BioMedGraphica_Conn_ID,BioMedGraphica_ID,PO,KEGG,Reactome
BMGC_PW0001,BMG_PW0002,"The various, enzyme-controlled, series of reactions allowing for the conversion of materials, energy availability and biodegradation of xenobiotics. [GO:0008152, http://www.onelook.com/ OneLook, Reactome:R-HSA-1430728]",,"Metabolic processes in human cells generate energy through the oxidation of molecules consumed in the diet and mediate the synthesis of diverse essential molecules not taken in the diet as well as the inactivation and elimination of toxic ones generated endogenously or present in the extracellular environment. The processes of energy metabolism can be classified into two groups according to whether they involve carbohydrate-derived or lipid-derived molecules, and within each group it is useful to distinguish processes that mediate the breakdown and oxidation of these molecules to yield energy from ones that mediate their synthesis and storage as internal energy reserves. Synthetic reactions are conveniently grouped by the chemical nature of the end products, such as nucleotides, amino acids and related molecules, and porphyrins. Detoxification reactions (biological oxidations) are likewise conveniently classified by the chemical nature of the toxin. At the same time, all of these processes are tightly integrated. Intermediates in reactions of energy generation are starting materials for biosyntheses of amino acids and other compounds, broad-specificity oxidoreductase enzymes can be involved in both detoxification reactions and biosyntheses, and hormone-mediated signaling processes function to coordinate the operation of energy-generating and energy-storing reactions and to couple these to other biosynthetic processes."
BMGC_PW0002,BMG_PW0003,"The pathways where a signal - hormone, neurotransmitter, growth factor, peptide, any molecule - triggers one or multiple cascades of events. This involves a number of molecules, including receptors, proteins, ligands, messengers, any participating molecule. A signaling pathway may be upstream or downstream of other signaling pathways. Signaling pathways control a very broad spectrum of processes as well as pathways. [GO:0007165, OneLook:www.onelook.com, Reactome:R-HSA-162582]",,"Signal transduction is a process in which extracellular signals elicit changes in cell state and activity. Transmembrane receptors sense changes in the cellular environment by binding ligands, such as hormones and growth factors, or reacting to other types of stimuli, such as light. Stimulation of transmembrane receptors leads to their conformational change which propagates the signal to the intracellular environment by activating downstream signaling cascades. Depending on the cellular context, this may impact cellular proliferation, differentiation, and survival. On the organism level, signal transduction regulates overall growth and behavior. Receptor tyrosine kinases (RTKs) transmit extracellular signals by phosphorylating their protein partners on conserved tyrosine residues. Some of the best studied RTKs are EGFR (reviewed in Avraham and Yarden, 2011), FGFR (reviewed in Eswarakumar et al, 2005), insulin receptor (reviewed in Saltiel and Kahn, 2001), NGF (reviewed in Reichardt, 2006), PDGF (reviewed in Andrae et al, 2008) and VEGF (reviewed in Xie et al, 2004). RTKs frequently activate downstream signaling through RAF/MAP kinases (reviewed in McKay and Morrison, 2007 and Wellbrock et al 2004), AKT (reviewed in Manning and Cantley, 2007) and PLC- gamma (reviewed in Patterson et al, 2005), which ultimately results in changes in gene expression and cellular metabolism. Receptor serine/threonine kinases of the TGF-beta family, such as TGF-beta receptors (reviewed in Kang et al. 2009) and BMP receptors (reviewed in Miyazono et al. 2009), transmit extracellular signals by phosphorylating regulatory SMAD proteins on conserved serine and threonine residues. This leads to formation of complexes of regulatory SMADs and SMAD4, which translocate to the nucleus where they act as transcription factors. WNT receptors transmit their signal through beta-catenin. In the absence of ligand, beta-catenin is constitutively degraded in a ubiquitin-dependent manner. WNT receptor stimulation releases beta-catenin from the destruction complex, allowing it to translocate to the nucleus where it acts as a transcriptional regulator (reviewed in MacDonald et al, 2009 and Angers and Moon, 2009). WNT receptors were originally classified as G-protein coupled receptors (GPCRs). Although they are structurally related, GPCRs primarily transmit their signals through G-proteins, which are trimers of alpha, beta and gamma subunits. When a GPCR is activated, it acts as a guanine nucleotide exchange factor, catalyzing GDP to GTP exchange on the G-alpha subunit of the G protein and its dissociation from the gamma-beta heterodimer. The G-alpha subunit regulates the activity of adenylate cyclase, while the gamma-beta heterodimer can activate AKT and PLC signaling (reviewed in Rosenbaum et al. 2009, Oldham and Hamm 2008, Ritter and Hall 2009). NOTCH receptors are activated by transmembrane ligands expressed on neighboring cells, which results in cleavage of NOTCH receptor and release of its intracellular domain. NOTCH intracellular domain translocates to the nucleus where it acts as a transcription factor (reviewed in Kopan and Ilagan, 2009). Integrins are activated by extracellular matrix components, such as fibronectin and collagen, leading to conformational change and clustering of integrins on the cell surface. This results in activation of integrin-linked kinase and other cytosolic kinases and, in co-operation with RTK signaling, regulates survival, proliferation and cell shape and adhesion (reviewed in Hehlgans et al, 2007) . Besides inducing changes in gene expression and cellular metabolism, extracellular signals that trigger the activation of Rho GTP-ases can trigger changes in the organization of cytoskeleton, thereby regulating cell polarity and cell-cell junctions (reviewed in Citi et al, 2011)."
BMGC_PW0003,BMG_PW0005,"Those metabolic reactions and pathways involved in the oxidation, breakdown and synthesis of carbohydrates in the tissue. The breakdown can be utilized by the body for energy production. The converse synthesis is used for energy storage. [GO:0005975, OneLook:www.onelook.com, Reactome:R-HSA-71387]","Carbon metabolism is the most basic aspect of life. This map presents an overall view of central carbon metabolism, where the number of carbons is shown for each compound denoted by a circle, excluding a cofactor (CoA, CoM, THF, or THMPT) that is replaced by an asterisk. The map contains carbon utilization pathways of glycolysis (map00010), pentose phosphate pathway (map00030), and citrate cycle (map00020), and six known carbon fixation pathways (map00710 and map00720) as well as some pathways of methane metabolism (map00680). The six carbon fixation pathways are: (1) reductive pentose phosphate cycle (Calvin cycle) in plants and cyanobacteria that perform oxygenic photosynthesis, (2) reductive citrate cycle in photosynthetic green sulfur bacteria and some chemolithoautotrophs, (3) 3-hydroxypropionate bi-cycle in photosynthetic green nonsulfur bacteria, two variants of 4-hydroxybutyrate pathways in Crenarchaeota called (4) hydroxypropionate-hydroxybutyrate cycle and (5) dicarboxylate-hydroxybutyrate cycle, and (6) reductive acetyl-CoA pathway in methanogenic bacteria.","Starches and sugars are major constituents of the human diet and the catabolism of monosaccharides, notably glucose, derived from them is an essential part of human energy metabolism (Dashty 2013). Glucose can be catabolized to pyruvate (glycolysis) and pyruvate synthesized from diverse sources can be metabolized to form glucose (gluconeogenesis). Glucose can be polymerized to form glycogen under conditions of glucose excess (glycogen synthesis), and glycogen can be broken down to glucose in response to stress or starvation (glycogenolysis). Other monosaccharides prominent in the diet, fructose and galactose, can be converted to glucose. The disaccharide lactose, the major carbohydrate in breast milk, is synthesized in the lactating mammary gland. The pentose phosphate pathway allows the synthesis of diverse monosaccharides from glucose including the pentose ribose-5-phosphate and the regulatory molecule xylulose-5-phosphate, as well as the generation of reducing equivalents for biosynthetic processes. Glycosaminoglycan metabolism and xylulose-5-phosphate synthesis from glucuronate are also annotated as parts of carbohydrate metabolism. The digestion of dietary starch and sugars and the uptake of the resulting monosaccharides into the circulation from the small intestine are annotated as parts of the “Digestion and absorption” pathway."
BMGC_PW0004,BMG_PW0007,"The mitogen-activated protein kinase pathway groups several serine/threonine protein kinase mediated cascades in response to a number of extracellular stimuli. A characteristic feature of these cascades is the presence of at least three kinases in series leading to the activation of a multifunctional MAP kinase. [GO:0000165, KEGG:map04010, PMID:14570565, PMID:14976517, PMID:17229475, PMID:17306385, Reactome:R-HSA-5683057]","The mitogen-activated protein kinase (MAPK) cascade is a highly conserved module that is involved in various cellular functions, including cell proliferation, differentiation and migration. Mammals express at least four distinctly regulated groups of MAPKs, extracellular signal-related kinases (ERK)-1/2, Jun amino-terminal kinases (JNK1/2/3), p38 proteins (p38alpha/beta/gamma/delta) and ERK5, that are activated by specific MAPKKs: MEK1/2 for ERK1/2, MKK3/6 for the p38, MKK4/7 (JNKK1/2) for the JNKs, and MEK5 for ERK5. Each MAPKK, however, can be activated by more than one MAPKKK, increasing the complexity and diversity of MAPK signalling. Presumably each MAPKKK confers responsiveness to distinct stimuli. For example, activation of ERK1/2 by growth factors depends on the MAPKKK c-Raf, but other MAPKKKs may activate ERK1/2 in response to pro-inflammatory stimuli.","The mitogen activated protein kinases (MAPKs) are a family of conserved protein serine threonine kinases that respond to varied extracellular stimuli to activate intracellular processes including gene expression, metabolism, proliferation, differentiation and apoptosis, among others. The classic MAPK cascades, including the ERK1/2 pathway, the p38 MAPK pathway, the JNK pathway and the ERK5 pathway are characterized by three tiers of sequentially acting, activating kinases (reviewed in Kryiakis and Avruch, 2012; Cargnello and Roux, 2011). The MAPK kinase kinase kinase (MAPKKK), at the top of the cascade, is phosphorylated on serine and threonine residues in response to external stimuli; this phosphorylation often occurs in the context of an interaction between the MAPKKK protein and a member of the RAS/RHO family of small GTP-binding proteins. Activated MAPKKK proteins in turn phosphorylate the dual-specificity MAPK kinase proteins (MAPKK), which ultimately phosphorylate the MAPK proteins in a conserved Thr-X-Tyr motif in the activation loop. Less is known about the activation of the atypical families of MAPKs, which include the ERK3/4 signaling cascade, the ERK7 cascade and the NLK cascade. Although the details are not fully worked out, these MAPK proteins don't appear to be phosphorylated downstream of a 3-tiered kinase system as described above (reviewed in Coulombe and Meloche, 2007; Cargnello and Roux, 2011) . Both conventional and atypical MAPKs are proline-directed serine threonine kinases and, once activated, phosphorylate substrates in the consensus P-X-S/T-P site. Both cytosolic and nuclear targets of MAPK proteins have been identified and upon stimulation, a proportion of the phosphorylated MAPKs relocalize from the cytoplasm to the nucleus. In some cases, nuclear translocation may be accompanied by dimerization, although the relationship between these two events is not fully elaborated (reviewed in Kryiakis and Avruch, 2012; Cargnello and Roux, 2011; Plotnikov et al, 2010)."
BMGC_PW0005,BMG_PW0008,"The secreted glycoproteins of the Wnt family regulate a wide spectrum of developmental processes and they are also playing important roles in the adult organism. Deregulation of Wnt cascades has oncogenic effects and is responsible for tumorigenesis in adults. [GO:0016055, KEGG:04310, PMID:12573432, PMID:15001769, PMID:15041171, Reactome:R-HSA-195721]","Wnt proteins are secreted morphogens that are required for basic developmental processes, such as cell-fate specification, progenitor-cell proliferation and the control of asymmetric cell division, in many different species and organs. There are at least three different Wnt pathways: the canonical pathway, the planar cell polarity (PCP) pathway and the Wnt/Ca2+ pathway. In the canonical Wnt pathway, the major effect of Wnt ligand binding to its receptor is the stabilization of cytoplasmic beta-catenin through inhibition of the bea-catenin degradation complex. Beta-catenin is then free to enter the nucleus and activate Wnt-regulated genes through its interaction with TCF (T-cell factor) family transcription factors and concomitant recruitment of coactivators. Planar cell polarity (PCP) signaling leads to the activation of the small GTPases RHOA (RAS homologue gene-family member A) and RAC1, which activate the stress kinase JNK (Jun N-terminal kinase) and ROCK (RHO-associated coiled-coil-containing protein kinase 1) and leads to remodelling of the cytoskeleton and changes in cell adhesion and motility. WNT-Ca2+ signalling is mediated through G proteins and phospholipases and leads to transient increases in cytoplasmic free calcium that subsequently activate the kinase PKC (protein kinase C) and CAMKII (calcium calmodulin mediated kinase II) and the phosphatase calcineurin.","WNT signaling pathways control a wide range of developmental and adult process in metozoans including cell proliferation, cell fate decisions, cell polarity and stem cell maintenance (reviewed in Saito-Diaz et al, 2013; MacDonald et al, 2009). The pathway is named for the WNT ligands, a large family of secreted cysteine-rich glycoproteins. At least 19 WNT members have been identified in humans and mice with distinct expression patterns during development (reviewed in Willert and Nusse, 2012). These ligands can activate at least three different downstream signaling cascades depending on which receptors they engage. In the so-called 'canonical' WNT signaling pathway, WNT ligands bind one of the 10 human Frizzled (FZD) receptors in conjunction with the LRP5/6 co-receptors to activate a transcriptional cascade that controls processes such as cell fate, proliferation and self-renenwal of stem cells. Engagement of the FZD-LRP receptor by WNT ligand results in the stabilization and translocation of cytosolic beta-catenin to the nucleus where it is a co-activator for LEF (lymphoid enhancer-binding factor)- and TCF (T cell factor) -dependent transcription. In the absence of WNT ligand, cytosolic beta-catenin is phosphorylated by a degradation complex consisting of glycogen synthase kinase 3 (GSK3), casein kinase 1 (CK1), Axin and Adenomatous polyposis coli (APC), and subsequently ubiquitinated and degraded by the 26S proteasome (reviewed in Saito-Diaz et al, 2013; Kimmelman and Xu, 2006). In addition to the beta-catenin-dependent transcriptional response, WNT signaling can also activate distinct non-transcriptional pathways that regulate cell migration and polarity. These beta-catenin-independent 'non-canonical' pathways signal through Frizzled receptors independently of LRP5/6, or occur through the tyrosine kinase receptors ROR and RYK (reviewed in Veeman et al, 2003; James et al, 2009). Non-canonical WNT pathways are best studied in Drosophila where the planar cell polarity (PCP) pathway controls the orientation of wing hairs and eye facets, but are also involved in processes such as convergent extension, neural tube closure, inner ear development and hair orientation in vertebrates and mammals(reviewed in Seifert and Mlodzik, 2007; Simons and Mlodzik, 2008). In the PCP pathway, binding of WNT ligand to the FZD receptor leads to activation of small Rho GTPases and JNK, which regulate the cytoskeleton and coordinate cell migration and polarity (reviewed in Lai et al, 2009; Schlessinger et al, 2009). In some cases, a FZD-WNT interaction increases intracellular calcium concentration and activates CaMK II and PKC; this WNT calcium pathway promotes cell migration and inhibits the canonical beta-catenin dependent transcriptional pathway (reviewed in Kuhl et al, 2000; Kohn and Moon, 2005; Rao et al 2010). Binding of WNT to ROR or RYK receptors also regulates cell migration, apparently through activation of JNK or SRC kinases, respectively, however the details of these pathways remain to be worked out (reviewed in Minami et al, 2010). Although the WNT signaling pathways were originally viewed as discrete, linear pathways controlled by defined subsets of 'canonical' or 'non-canonical' ligands and receptors, the emerging evidence is challenging this notion. Instead, the specificity and the downstream response appear to depend on the particular cellular context and vary with species, tissue and stage of development (reviewed in van Amerongen and Nusse, 2009; Rao et al, 2010)."
BMGC_PW0006,BMG_PW0009,"Apoptosis is a programmed cell death pathway that is characterized by particular morphological features such as membrane blebbing and DNA fragmentation. It can be intrinsic or extrinsic and involves the activation of caspases. [GO:0006915, KEGG:map04210, PMID:12196263, PMID:18414491, Reactome:R-HSA-109581]","Apoptosis is a genetically programmed process for the elimination of damaged or redundant cells by activation of caspases (aspartate-specific cysteine proteases). The onset of apoptosis is controlled by numerous interrelating processes. The 'extrinsic' pathway involves stimulation of members of the tumor necrosis factor (TNF) receptor subfamily, such as TNFRI, CD95/Fas or TRAILR (death receptors), located at the cell surface, by their specific ligands, such as TNF-alpha, FasL or TRAIL, respectively. The 'intrinsic' pathway is activated mainly by non-receptor stimuli, such as DNA damage, ER stress, metabolic stress, UV radiation or growth-factor deprivation. The central event in the 'intrinsic' pathway is the mitochondrial outer membrane permeabilization (MOMP), which leads to the release of cytochrome c. These two pathways converge at the level of effector caspases, such as caspase-3 and caspase-7. The third major pathway is initiated by the constituents of cytotoxic granules (e.g. Perforin and Granzyme B) that are released by CTLs (cytotoxic T-cells) and NK (natural killer) cells. Granzyme B, similarly to the caspases, cleaves its substrates after aspartic acid residues, suggesting that this protease has the ability to activate members of the caspase family directly. It is the balance between the pro-apoptotic and anti-apoptotic signals that eventually determines whether cells will undergo apoptosis, survive or proliferate. TNF family of ligands activates anti-apoptotic or cell-survival signals as well as apoptotic signals. NGF and Interleukin-3 promotes the survival, proliferation and differentiation of neurons or hematopoietic cells, respectively. Withdrawal of these growth factors leads to cell death, as described above.","Apoptosis is a distinct form of cell death that is functionally and morphologically different from necrosis. Nuclear chromatin condensation, cytoplasmic shrinking, dilated endoplasmic reticulum, and membrane blebbing characterize apoptosis in general. Mitochondria remain morphologically unchanged. In 1972 Kerr et al introduced the concept of apoptosis as a distinct form of ""cell-death"", and the mechanisms of various apoptotic pathways are still being revealed today. The two principal pathways of apoptosis are (1) the Bcl-2 inhibitable or intrinsic pathway induced by various forms of stress like intracellular damage, developmental cues, and external stimuli and (2) the caspase 8/10 dependent or extrinsic pathway initiated by the engagement of death receptors The caspase 8/10 dependent or extrinsic pathway is a death receptor mediated mechanism that results in the activation of caspase-8 and caspase-10. Activation of death receptors like Fas/CD95, TNFR1, and the TRAIL receptor is promoted by the TNF family of ligands including FASL (APO1L OR CD95L), TNF, LT-alpha, LT-beta, CD40L, LIGHT, RANKL, BLYS/BAFF, and APO2L/TRAIL. These ligands are released in response to microbial infection, or as part of the cellular, humoral immunity responses during the formation of lymphoid organs, activation of dendritic cells, stimulation or survival of T, B, and natural killer (NK) cells, cytotoxic response to viral infection or oncogenic transformation. The Bcl-2 inhibitable or intrinsic pathway of apoptosis is a stress-inducible process, and acts through the activation of caspase-9 via Apaf-1 and cytochrome c. The rupture of the mitochondrial membrane, a rapid process involving some of the Bcl-2 family proteins, releases these molecules into the cytoplasm. Examples of cellular processes that may induce the intrinsic pathway in response to various damage signals include: auto reactivity in lymphocytes, cytokine deprivation, calcium flux or cellular damage by cytotoxic drugs like taxol, deprivation of nutrients like glucose and growth factors like EGF, anoikis, transactivation of target genes by tumor suppressors including p53. In many non-immune cells, death signals initiated by the extrinsic pathway are amplified by connections to the intrinsic pathway. The connecting link appears to be the truncated BID (tBID) protein a proteolytic cleavage product mediated by caspase-8 or other enzymes."
BMGC_PW0007,BMG_PW0010,"The metabolic reactions involved in the oxidation, utilization and/or synthesis of lipids in tissues. [GO:0006629, OneLook:www.onelook.com, Reactome:R-HSA-556833]",,"Lipids are hydrophobic but otherwise chemically diverse molecules that play a wide variety of roles in human biology. They include ketone bodies, fatty acids, triacylglycerols, phospholipids and sphingolipids, eicosanoids, cholesterol, bile salts, steroid hormones, and fat-soluble vitamins. They function as a major source of energy (fatty acids, triacylglycerols, and ketone bodies), are major constituents of cell membranes (cholesterol and phospholipids), play a major role in their own digestion and uptake (bile salts), and participate in numerous signaling and regulatory processes (steroid hormones, eicosanoids, phosphatidylinositols, and sphingolipids) (Vance & Vance 2008 - URL). The central steroid in human biology is cholesterol, obtained from animal fats consumed in the diet or synthesized de novo from acetyl-coenzyme A. (Vegetable fats contain various sterols but no cholesterol.) Cholesterol is an essential constituent of lipid bilayer membranes and is the starting point for the biosyntheses of bile acids and salts, steroid hormones, and vitamin D. Bile acids and salts are mostly synthesized in the liver. They are released into the intestine and function as detergents to solubilize dietary fats. Steroid hormones are mostly synthesized in the adrenal gland and gonads. They regulate energy metabolism and stress responses (glucocorticoids), salt balance (mineralocorticoids), and sexual development and function (androgens and estrogens). At the same time, chronically elevated cholesterol levels in the body are associated with the formation of atherosclerotic lesions and hence increased risk of heart attacks and strokes. The human body lacks a mechanism for degrading excess cholesterol, although an appreciable amount is lost daily in the form of bile salts and acids that escape recycling. Aspects of lipid metabolism currently annotated in Reactome include lipid digestion, mobilization, and transport; fatty acid, triacylglycerol, and ketone body metabolism; peroxisomal lipid metabolism; phospholipid and sphingolipid metabolism; cholesterol biosynthesis; bile acid and bile salt metabolism; and steroid hormone biosynthesis."
BMGC_PW0008,BMG_PW0012,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of nucleotides. Nucleotides, which are the units of DNA and RNA, can also play important roles in cellular energy, enzyme regulation as well as serve as signaling molecules. [GO:0009117, PMID:20561600, PMID:21222015, Reactome:R-HSA-15869]",,"Nucleotides and their derivatives are used for short-term energy storage (ATP, GTP), for intra- and extra-cellular signaling (cAMP; adenosine), as enzyme cofactors (NAD, FAD), and for the synthesis of DNA and RNA. Most dietary nucleotides are consumed by gut flora; the human body's own supply of these molecules is synthesized de novo. Additional metabolic pathways allow the interconversion of nucleotides, the salvage and reutilization of nucleotides released by degradation of DNA and RNA, the catabolism of excess nucleotides, and the transport of these molecules between the cytosol and the nucleus (Rudolph 1994). These pathways are regulated to control the total size of the intracellular nucleotide pool, to balance the relative amounts of individual nucleotides, and to couple the synthesis of deoxyribonucleotides to the onset of DNA replication (S phase of the cell cycle). These pathways are also of major clinical interest as they are the means by which nucleotide analogues used as anti-viral and anti-tumor drugs are taken up by cells, activated, and catabolized (Weilin and Nordlund 2010). As well, differences in nucleotide metabolic pathways between humans and aplicomplexan parasites like Plasmodium have been exploited to design drugs to attack the latter (Hyde 2007). The movement of nucleotides and purine and pyrimidine bases across lipid bilayer membranes, mediated by SLC transporters, is annotated as part of the module ""transmembrane transport of small molecules""."
BMGC_PW0009,BMG_PW0013,"Complex human diseases encompass a spectrum of genetic and environmental attributes that together affect the normal functioning of several molecular and cellular pathways. Their combined and accumulated effect is manifested in the anomalous phenotype of the complex condition. [InHouse:InHouse_PW_dictionary, Reactome:R-HSA-1643685]",,"Biological processes are captured in Reactome by identifying the molecules (DNA, RNA, protein, small molecules) involved in them and describing the details of their interactions. From this molecular viewpoint, human disease pathways have three mechanistic causes: the inclusion of microbially-expressed proteins, altered functions of human proteins, or changed expression levels of otherwise functionally normal human proteins. The first group encompasses the infectious diseases such as influenza, tuberculosis and HIV infection. The second group involves human proteins modified either by a mutation or by an abnormal post-translational event that produces an aberrant protein with a novel function. Examples include somatic mutations of EGFR and FGFR (epidermal and fibroblast growth factor receptor) genes, which encode constitutively active receptors that signal even in the absence of their ligands, or the somatic mutation of IDH1 (isocitrate dehydrogenase 1) that leads to an enzyme active on 2-oxoglutarate rather than isocitrate, or the abnormal protein aggregations of amyloidosis which lead to diseases such as Alzheimer's. Infectious diseases are represented in Reactome as microbial-human protein interactions and the consequent events. The existence of variant proteins and their association with disease-specific biological processes is represented by inclusion of the modified protein in a new or variant reaction, an extension to the 'normal' pathway. Diseases which result from proteins performing their normal functions but at abnormal rates can also be captured, though less directly. Many mutant alleles encode proteins that retain their normal functions but have abnormal stabilities or catalytic efficiencies, leading to normal reactions that proceed to abnormal extents. The phenotypes of such diseases can be revealed when pathway annotations are combined with expression or rate data from other sources. Depending on the biological pathway/process immediately affected by disease-causing gene variants, non-infectious diseases in Reactome are organized into diseases of signal transduction by growth factore receptors and second messengers, diseases of mitotic cell cycle, diseases of cellular response to stress, diseases of programmed cell death, diseases of DNA repair, disorders of transmembrane transporters, diseases of metabolism, diseases of immune system, diseases of neuronal system, disorders of developmental biology, disorders of extracellular matrix organization, and diseases of hemostatis."
BMGC_PW0010,BMG_PW0014,"Neurodegenerative diseases group together a number of conditions of various and many times poorly understood origins that are characterized by the progressive loss of particular neurons, the formation of particular structures such as plaques and fibrils, and protein aggregates. Proteosomal degradation, programmed cell death and oxidative stress are among a number of pathways thought to be disrupted. [inHouse:InHouse_PW_dictionary, Reactome:R-HSA-8863678]",,"Neurodegenerative diseases manifest as the progressive dysfunction and loss of neurons, which is frequently accompanied by formation of misfolded protein deposits in the brain. Classification of neurodegenerative diseases is based on clinical symptoms, which depend on the anatomical region affected by neuronal dysfunction, the identity of misfolded proteins and cellular and subcellular pathology. In Alzheimer’s disease (AD), beta-amyloid protein (APP) deposits form in the extracellular space, where they can make plaques, while abnormally phosphorylated tau protein (MAPT) accumulates in neuronal cells. Beside AD, neuronal and/or glial inclusions of hyperphosphorylated tau are also found in Pick disease (PiD), neurofibrillary tangle-dementia (NFT), primary age-related tauopathy (PART), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), argyrophilic grain disease (AGD) and globular glial tauopathies (GGT). In prion disease, such as Creutzfeldt-Jakob disease, deposits of PrP protein are formed mostly in the extracellular and presynaptic space. PrP deposits in neuronal cell bodies are mainly confined to endosomes and lysosomes, which is attributed to neuronal uptake of pathological proteins and intercellular prion spreading. In Parkinson disease (PD) and dementia with Lewy bodies (DLB), deposits of alpha-synuclein (SNCA) are formed in the cytoplasm of neuronal cell bodies and neurites. In multiple system atrophy (MSA), deposits of alpha-synuclein form in the cytoplasm of glial cells (Papp-Lantos bodies). Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are characterized by ubiquitin-positive cytoplasmic inclusions of TAR DNA-binding protein 43 (TARDBP, commonly known as TDP-43), a protein that normally localizes to the nucleus. Pathological TDP-43 inclusions have been associated with the TDP-43 gene mutations, as well as mutations in several other genes, including C9orf72, GRN, VCP, SQSTM1, DCTN1 and OPTN. TDP-43 inclusions have also been reported in AD, DLB, hippocampal sclerosis (HS) and chronic traumatic encephalopathy. FUS protein-positive inclusion bodies are found in familial ALS, caused by mutations in the FUS gene, as well as in a small subgroup of FTLD-related diseases. FUS-positive inclusions may be accompanied by FET protein-positive inclusions. For a detailed review of molecular pathology of neurodegenerative diseases, please refer to Kovacs 2016. Within this broad domain, the process by which APP-triggered deregulation of CDK5 (cyclin-dependent kinase 5) triggers multiple neurodegenerative pathways associated with Alzheimer's disease has been annotated."
BMGC_PW0011,BMG_PW0015,"A mostly sporadic, late-onset condition affecting the central nervous system, that is the most prevalent neurodegenerative disease and the most common form of dementia. It is characterized by the presence of amyloid plaques and fibril tangles. Possible pathways affected range from protein mis-folding and aggregation, to oxidative stress and impaired metal homeostasis. [InHouse:InHouse_PW_dictionary, KEGG:map05010]","Alzheimer disease (AD) is a chronic disorder that slowly destroys neurons and causes serious cognitive disability. AD is associated with senile plaques and neurofibrillary tangles (NFTs). Amyloid-beta (Abeta), a major component of senile plaques, has various pathological effects on cell and organelle function. To date genetic studies have revealed four genes that may be linked to autosomal dominant or familial early onset AD (FAD). These four genes include: amyloid precursor protein (APP), presenilin 1 (PS1), presenilin 2 (PS2) and apolipoprotein E (ApoE). All mutations associated with APP and PS proteins can lead to an increase in the production of Abeta peptides, specfically the more amyloidogenic form, Abeta42. It was proposed that Abeta form Ca2+ permeable pores and bind to and modulate multiple synaptic proteins, including NMDAR, mGluR5 and VGCC, leading to the overfilling of neurons with calcium ions. Consequently, cellular Ca2+ disruptions will lead to neuronal apoptosis, autophagy deficits, mitochondrial abnormality, defective neurotransmission, impaired synaptic plasticity and neurodegeneration in AD. FAD-linked PS1 mutation downregulates the unfolded protein response and leads to vulnerability to ER stress.",
BMGC_PW0012,BMG_PW0016,"A late onset, mostly sporadic neurodegenerative disease characterized by the loss of motor neurons in the brain stem and spinal cord. Various pathways are thought to be deregulated and contribute to the condition; among them calcium and/or zinc homeostasis, apoptosis, Cdk5 and calcineurin dependent processes, and in the case of the more rare, genetically inherited form of the disease, mutations in the cytosolic Cu, Zn superoxide dismutase (SOD1) and the subsequent changes in the processes that involve SOD1. [InHouse:In_House_PW_dictionary, KEGG:map05014]","Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by a progressive degeneration of motor neurons in the brain and spinal cord. In 90% of patients, ALS is sporadic, with no clear genetic linkage. On the other hand, the remaining 10% of cases show familial inheritance, with mutations in SOD1, TDP43(TARDBP), FUS, or C9orf72 genes being the most frequent causes. In spite of such difference, familial ALS and sporadic ALS have similarities in their pathological features. Proposed disease mechanisms contributing to motor neuron degeneration in ALS are: impaired proteostasis, aberrant RNA processing, mitochondrial disfunction and oxidative stress, microglia activation, and axonal dysfunction.",
BMGC_PW0013,BMG_PW0018,"One of the most common neurodegenerative diseases that is characterized by the loss of dopaminergic neurons in the substantia nigra and the presence of cytoplasmic inclusions called Lewy bodies in surrounding neurons. Several pathways are thought to be deregulated; for instance, imbalance of iron homeostasis is believed to contribute to the pathogenesis of the condition. [KEGG:map05012, PMID:18052765, PMID:19422283]","Parkinson disease (PD) is a progressive neurodegenerative movement disorder that results primarily from the death of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc). Both environmental factors and mutations in familial PD-linked genes such as SNCA, Parkin, DJ-1, PINK1 and LRRK2 are associated with PD pathogenesis. These pathogenic mutations and environmental factors are known to cause disease due to oxidative stress, intracellular Ca2+ homeostasis impairment, mitochondrial dysfunctions and altered protein handling compromising key roles of DA neuronal function and survival. The demise of DA neurons located in the SNc leads to a drop in the dopaminergic input to the striatum, which is hypothesized to impede movement by inducing hypo and hyper activity in striatal spiny projection neurons (SPNs) of the direct (dSPNs) and indirect (iSPNs) pathways in the basal ganglia, respectively.",
BMGC_PW0014,BMG_PW0019,"Prion disease - any of a group of fatal, transmissible neurodegenerative diseases caused by abnormalities of prion protein metabolism, which may result from mutations in the prion protein gene or from infection with pathogenic isoforms of the protein.  Characteristics include neuronal loss, gliosis, and extensive vacuolization of the cerebral cortex. Prion diseases may be sporadic, inherited as an autosomal dominant trait, or acquired. Human diseases include Creutzfeldt-Jakob disease, Gerstmann-Strussler syndrome, fatal familial insomnia, and kuru [KEGG:map05020, OneLook:www.onelook.com]","Prion diseases, also termed transmissible spongiform encephalopathies (TSEs), are a group of fatal neurodegenerative diseases that affect humans and a number of other animal species. The etiology of these diseases is thought to be associated with the conversion of a normal protein, PrPC, into an infectious, pathogenic form, PrPSc. The conversion is induced by prion infections (for example, variant Creutzfeldt-Jakob disease (vCJD), iatrogenic CJD, Kuru), mutations (familial CJD, Gerstmann-Straussler-Scheinker syndrome, fatal familial insomnia (FFI)) or unknown factors (sporadic CJD (sCJD)), and is thought to occur after PrPC has reached the plasma membrane or is re-internalized for degradation. The PrPSc form shows greater protease resistance than PrPC and accumulates in affected individuals, often in the form of extracellular plaques. Pathways that may lead to neuronal death comprise oxidative stress, regulated activation of complement, ubiquitin-proteasome and endosomal-lysosomal systems, synaptic alterations and dendritic atrophy, corticosteroid response, and endoplasmic reticulum stress. In addition, the conformational transition could lead to the lost of a beneficial activity of the natively folded protein, PrPC.",
BMGC_PW0015,BMG_PW0023,"The Immune response pathways mediate the defense of host cells against infection and injury. The first line of defense is provided by the phylogenetically older innate immune response. The later, more versatile response is provided by the pathways of adaptive immunity: the B cell mediated humoral and the T cell mediated cellular or cell-mediated responses. [GO:0006955, MCW_library:Handbook_of_cellular_and_molecular_immunology, OneLook:www.onelook.com, Reactome:R-HSA-168256]",,"Humans are exposed to millions of potential pathogens daily, through contact, ingestion, and inhalation. Our ability to avoid infection depends on the adaptive immune system and during the first critical hours and days of exposure to a new pathogen, our innate immune system."
BMGC_PW0016,BMG_PW0025,"Those metabolic reactions involved in the energy-yielding conversion of glucose to pyruvate or in the formation of glucose from non-carbohydrate precursors such as pyruvate, lactate, citric acid cycle intermediates, the carbon skeleton of many amino acids. While many enzymes are shared by the two pathways, a few steps are carried out by pathway-specific enzymes. The two pathways are independently regulated. [KEGG:map00010]","Glycolysis is the process of converting glucose into pyruvate and generating small amounts of ATP (energy) and NADH (reducing power). It is a central pathway that produces important precursor metabolites: six-carbon compounds of glucose-6P and fructose-6P and three-carbon compounds of glycerone-P, glyceraldehyde-3P, glycerate-3P, phosphoenolpyruvate, and pyruvate [MD:M00001]. Acetyl-CoA, another important precursor metabolite, is produced by oxidative decarboxylation of pyruvate [MD:M00307]. When the enzyme genes of this pathway are examined in completely sequenced genomes, the reaction steps of three-carbon compounds from glycerone-P to pyruvate form a conserved core module [MD:M00002], which is found in almost all organisms and which sometimes contains operon structures in bacterial genomes. Gluconeogenesis is a synthesis pathway of glucose from noncarbohydrate precursors. It is essentially a reversal of glycolysis with minor variations of alternative paths [MD:M00003].",
BMGC_PW0017,BMG_PW0026,"The series of chemical reactions that are central to all aerobic cells and constitute the citric acid cycle. Also known as the tricarboxylic acid cycle (TCA) or Krebs cycle, it is the center of convergence for all molecular fuels. [GO:0006099, KEGG:map00020, OneLook:www.onelook.com, Reactome:R-HSA-71403, SMP:00057]","The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011].","In the citric acid or tricarboxylic acid (TCA) cycle, the acetyl group of acetyl CoA (derived primarily from oxidative decarboxylation of pyruvate, beta-oxidation of long-chain fatty acids, and catabolism of ketone bodies and several amino acids) can be completely oxidized to CO2 in reactions that also yield one high-energy phosphate bond (as GTP or ATP) and four reducing equivalents (three NADH + H+, and one FADH2). Then, the electron transport chain oxidizes NADH and FADH2 to yield nine more high-energy phosphate bonds (as ATP). All reactions of the citric acid cycle take place in the mitochondrion. Eight canonical reactions mediate the synthesis of citrate from acetyl-CoA and oxaloacetate and the metabolism of citrate to re-form oxaloacetate. Three reactions are reversible: the interconversions of citrate and isocitrate, of fumarate and malate, and of malate and oxaloacetate. The reverse reactions are irrelevant under normal physiological conditions but appear to have a role in glucose- and glutamine-stimulated insulin secretion (Zhang et al., 2020) and cancer metabolism (e.g., Jiang et al., 2016). Succinate synthesis from succinyl-CoA can be coupled to the phosphorylation of either GDP (the canonical reaction) or ADP; we annotate both reactions. Two mitochondrial isocitrate dehydrogenase isozymes catalyze the oxidative decarboxylation of isocitrate to form alpha-ketoglutarate (2-oxoglutarate): IDH3 catalyzes the canonical reaction coupled to the reduction of NAD+, while IDH2 catalyzes the same reaction coupled to the reduction of NADP+, a reaction whose normal physiological function is unclear. Both reactions are annotated. The cyclical nature of the reactions responsible for the oxidation of acetate was first suggested by Hans Krebs from biochemical studies of pigeon breast muscle (Krebs et al., 1938; Krebs and Eggleston, 1940). Ochoa and colleagues studied many molecular details of individual reactions, mainly by studying enzymes purified from pig hearts (Ochoa, 1980). While the human homologs of these enzymes have all been identified, their biochemical characterization has, in general, been limited, and many molecular details of the human reactions are inferred from those worked out in studies of the model systems. Studies examining the impact of elevated citric acid cycle intermediates such as succinate and fumarate led to the recognition of the role of metabolites in driving cancer progression ('oncometabolites') (Pollard et al., 2005; reviewed in Hayashi et al., 2018). The role of TCA enzymes in disease was reviewed by Kang et al., 2021."
BMGC_PW0018,BMG_PW0029,"Acetyl-CoA, the starting material for fatty acid biosynthesis, can be derived from amino acid and lipid degradation or the oxidative decarboxylation of pyruvate. Fatty acid biosynthesis involves the condensation of C2 units; it requires seven enzymatic reactions which are carried out by the multifunctional enzyme fatty acid synthase. [GO:0006633, KEGG:00061, PMID:11248039, PMID:8001737, SMP:00456]",,
BMGC_PW0019,BMG_PW0030,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of purines. Purines consist of a pyrimidine ring fused to an imidazole ring. The nucleobases adenine and guanine in DNA are purines. [GO:0006144, KEGG:00230, OneLook:www.onelook.com, SMP:00050]",,
BMGC_PW0020,BMG_PW0031,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of pyrimidines. Cytosine, thymine and uracil - the nucleobases found in nucleic acids, are pyrimidine derivatives. [GO:0006206, KEGG:00240, OneLook:www.onelook.com, SMP:00046]",,
BMGC_PW0021,BMG_PW0033,"Those metabolic reactions whereby the electrons, derived from the oxidation of glucose and lipids or the degradation of amino acids, are passed to oxygen via a series of series of spatially separated complexes. The energy derived generates an electrochemical gradient that drives the synthesis of ATP. The coupling between the electron transport chain, also known as the respiratory chain, and the ATP biosynthetic pathway is known as oxidative phosphorylation. Under certain circumstances the two may be uncoupled. [GO:0022904, OneLook:www.onelook.com, PMID:19760284, PMID:21625217, Reactome:R-HSA-611105, SMP:00355]",,"Mitochondria are often described as the ""powerhouse"" of a cell as it is here that energy is largely released from the oxidation of food. Reducing equivalents generated from beta-oxidation of fatty acids and from the Krebs cycle enter the electron transport chain (also called the respiratory chain). During a series of redox reactions, electrons travel down the chain releasing their energy in controlled steps. These reactions drive the active transport of protons from the mitochondrial matrix , through the inner membrane to the intermembrane space. The respiratory chain consists of five main types of carrier; flavins, iron-sulfur centres, quinones, cytochromes (heme proteins) and copper. The two main reducing equivalents entering the respiratory chain are NADH and FADH2. NADH is linked through the NADH-specific dehydrogenase whereas FADH2 is reoxidised within succinate dehydrogenase and a ubiquinone reductase of the fatty acid oxidation pathway. Oxygen is the final acceptor of electrons and with protons, is converted to form water, the end product of aerobic cellular respiration. A proton electrochemical gradient (often called protonmotive force) is established across the inner membrane, with positive charge in the intermembrane space relative to the matrix. Protons driven by the proton-motive force, can enter ATP synthase thus returning to the mitochondrial matrix. ATP synthases use this exergonic flow to form ATP in the matrix, a process called chemiosmotic coupling. A by-product of this process is heat generation. An antiport, ATP-ADP translocase, preferentially exports ATP from the matrix thereby maintaining a high ADP:ATP ratio in the matrix. The tight coupling of electron flow to ATP synthesis means oxygen consumption is dependent on ADP availability (termed respiratory control). High ADP (low ATP) increases electron flow thereby increasing oxygen consumption and low ADP (high ATP) decreases electron flow and thereby decreases oxygen consumption. There are many inhibitors of mitochondrial ATP synthesis. Most act by either blocking the flow of electrons (eg cyanide, carbon monoxide, rotenone) or uncoupling electron flow from ATP synthesis (eg dinitrophenol). Thermogenin is a natural protein found in brown fat. Newborn babies have a large amount of brown fat and the heat generated by thermogenin is an alternative to ATP synthesis (and thus electron flow only produces heat) and allows the maintenance of body temperature in newborns. The electron transport chain is located in the inner mitochondrial membrane and comprises some 80 proteins organized in four enzymatic complexes (I-IV). Complex V generates ATP but has no electron transfer activity. In addition to these 5 complexes, there are also two electron shuttle molecules; Coenzyme Q (also known as ubiquinone, CoQ) and Cytochrome c (Cytc). These two molecules shuttle electrons between the large complexes in the chain. How many ATPs are generated by this process? Theoretically, for each glucose molecule, 32 ATPs can be produced. As electrons drop from NADH to oxygen in the chain, the number of protons pumped out and returning through ATP synthase can produce 2.5 ATPs per electron pair. For each pair donated by FADH2, only 1.5 ATPs can be formed. Twelve pairs of electrons are removed from each glucose molecule; 10 by NAD+ = 25 ATPs 2 by FADH2 = 3 ATPs. Making a total of 28 ATPs. However, 2 ATPs are formed during the Krebs' cycle and 2 ATPs formed during glycolysis for each glucose molecule therefore making a total ATP yield of 32 ATPs. In reality, the energy from the respiratory chain is used for other processes (such as active transport of important ions and molecules) so under conditions of normal respiration, the actual ATP yield probably does not reach 32 ATPs. The reducing equivalents that fuel the electron transport chain, namely NADH and FADH2, are produced by the Krebs cycle (TCA cycle) and the beta-oxidation of fatty acids. At three steps in the Krebs cycle (isocitrate conversion to oxoglutarate; oxoglutarate conversion to succinyl-CoA; Malate conversion to oxaloacetate), a pair of electrons (2e-) are removed and transferred to NAD+, forming NADH and H+. At a single step, a pair of electrons are removed from succinate, reducing FAD to FADH2. From the beta-oxidation of fatty acids, one step in the process forms NADH and H+ and another step forms FADH2. Cytoplasmic NADH, generated from glycolysis, has to be oxidized to reform NAD+, essential for glycolysis, otherwise glycolysis would cease to function. There is no carrier that transports NADH directly into the mitochondrial matrix and the inner mitochondrial membrane is impermeable to NADH so the cell uses two shuttle systems to move reducing equivalents into the mitochondrion and regenerate cytosolic NAD+. The first is the glycerol phosphate shuttle, which uses electrons from cytosolic NADH to produce FADH2 within the inner membrane. These electrons then flow to Coenzyme Q. Complex I is bypassed so only 1.5 ATPs can be formed per NADH via this route. The overall balanced equation, summing all the reactions in this system, is NADH (cytosol) + H+ (cytosol) + NAD+ (mito.) = NAD+ (cytosol) + NADH (mito.) + H+ (mito.) The malate-aspartate shuttle uses the oxidation of malate to generate NADH in the mitochondrial matrix. This NADH can then be fed directly to complex I and thus can form 3 ATPs via the respiratory chain. The overall balanced equation is NADH (cytosol) + H+ (cytosol) + FAD (inner memb.) = NAD+ (cytosol) + FADH2 (inner memb.) Both of these shuttle systems regenerate cytosolic NAD+. The entry point for NADH is complex I (NADH dehydrogenase) and the entry point for FADH2 is Coenzyme Q. The input of electrons from fatty acid oxidation via ubiquinone is complicated and not shown in the diagram."
BMGC_PW0022,BMG_PW0035,Those metabolic reactions in the nitrogen cycle carried out by various microorganisms. [KEGG:map00910],"The biological process of the nitrogen cycle is a complex interplay among different microorganisms catalyzing different reactions, where nitrogen is found in various oxidation states ranging from +5 in nitrate to -3 in ammonia. The core nitrogen cycle involves four reduction pathways and two oxidation pathways. Nitrogen fixation [MD:M00175] is the process of reducing atmospheric molecular nitrogen to ammonia, a biologically useful reduced form incorporated into amino acids and other vital compounds. The ability of fixing atmospheric nitrogen by the nitrogenase enzyme complex is present in restricted prokaryotes (diazotrophs). The other reduction pathways are assimilatory nitrate reduction [MD:M00531] and dissimilatory nitrate reduction [MD:M00530] both for conversion to ammonia, and denitrification [MD:M00529]. Denitrification is a respiration in which nitrate or nitrite is reduced as a terminal electron acceptor under low oxygen or anoxic conditions, producing gaseous nitrogen compounds (N2, NO and N2O) to the atmosphere. The two oxidation pathways are nitrification [MD:M00528] and anaerobic ammonium oxidation (anammox) [MD:M00973]. Nitrification is the oxidation of ammonia (NH3) with oxygen into nitrite followed by the oxidation of nitrite into nitrate. The first step is performed by ammonia-oxidizing microorganisms (e.g., Nitrosomonas and Nitrosococcus) and the second step by nitrite-oxidizing microorganisms (e.g., Nitrobacter). Anammox is a biochemical process of oxidizing ammonium (NH4+) into dinitrogen gas (N2) using nitrite as an electron acceptor. It occurs in the anammoxosome, a membrane bound compartment inside the cytoplasm, of anammox bacteria (e.g., Planctomycetes).",
BMGC_PW0023,BMG_PW0038,"Those metabolic reactions involved in the biosynthesis of bile acids - any of the steroid carboxylic acids derived from cholesterol. Cholic and chenodeoxycholic acids are the primary bile acids and are formed in the liver. Secondary bile acids - deoxycholic and lithocholic - are formed from the primary bile acids through the action of intestinal bacteria. Bile acid also acts as a signal molecule via several nuclear receptors. [GO:0006699, KEGG:00120, OneLook:www.onelook.com, PMID:22414897, SMP:00035]","Bile acids are steroid carboxylic acids derived from cholesterol in vertebrates. The primary bile acids, cholic acid and chenodeoxycholic acid, are synthesized in the liver and conjugated with taurine or glycine before secretion via bile into the intestine. The conversion from cholesterol to cholic and chenodeoxycholic acids involves four steps: 1) the initiation of synthesis by 7alpha-hydroxylation of sterol precursors, 2) further modifications to the ring structures, 3) side-chain oxidation and shortening (cleavage) by three carbons, and 4) conjugation of the bile acid with taurine or glycine.",
BMGC_PW0024,BMG_PW0040,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of fructose and mannose, as depicted in the KEGG diagram. [KEGG:map00051, OneLook:www.onelook.com]",,
BMGC_PW0025,BMG_PW0042,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of pyruvate - a salt, ester, or anionic form of pyruvic acid. Pyruvate, which is the end-product of glycolysis, can be converted to lactate under anaerobic conditions, can be further oxidized via the Krebs or citrate cycle or can be converted back to glucose via gluconeogenesis. [GO:0006090, KEGG:00620, KEGG:00620, OneLook:www.onelook.com, Reactome:R-HSA-70268, SMP:00060]",,"Pyruvate sits at an intersection of key pathways of energy metabolism. It is the end product of glycolysis and the starting point for gluconeogenesis and can be generated by the transamination of alanine. The pyruvate dehydrogenase complex can convert it to acetyl CoA (Reed and Hackert 1990), which can enter the TCA cycle or serve as the starting point for the syntheses of long-chain fatty acids, steroids, and ketone bodies depending on the tissue and metabolic state in which it is formed. It also plays a central role in balancing the energy needs of various tissues in the body. Under conditions in which oxygen supply is limiting, e.g., in exercising muscle, or in the absence of mitochondria, e.g., in red blood cells, re-oxidation of NADH produced by glycolysis cannot be coupled to the generation of ATP. Instead, re-oxidation is coupled to the reduction of pyruvate to lactate. This lactate is released into the blood and taken up primarily by the liver, where it is oxidized to pyruvate and can be used for gluconeogenesis (Cori 1981). For a recent review, see Prochownik & Wang, 2021."
BMGC_PW0026,BMG_PW0044,"Those metabolic reactions involved in the generation of reducing equivalents and five carbon (pentose) sugars. The oxidative phase is irreversible; the non-oxidative is reversible. [GO:0006098, KEGG:map00030, OneLook:www.oneloook.com, Reactome:R-HSA-71336, SMP:00031]","The pentose phosphate pathway is a process of glucose turnover that produces NADPH as reducing equivalents and pentoses as essential parts of nucleotides. There are two different phases in the pathway. One is irreversible oxidative phase in which glucose-6P is converted to ribulose-5P by oxidative decarboxylation, and NADPH is generated [MD:M00006]. The other is reversible non-oxidative phase in which phosphorylated sugars are interconverted to generate xylulose-5P, ribulose-5P, and ribose-5P [MD:M00007]. Phosphoribosyl pyrophosphate (PRPP) formed from ribose-5P [MD:M00005] is an activated compound used in the biosynthesis of histidine and purine/pyrimidine nucleotides. This pathway map also shows the Entner-Doudoroff pathway where 6-P-gluconate is dehydrated and then cleaved into pyruvate and glyceraldehyde-3P [MD:M00008].","The pentose phosphate pathway is responsible for the generation of a substantial fraction of the cytoplasmic NADPH required for biosynthetic reactions, and for the generation of ribose 5-phosphate for nucleotide synthesis. Although the pentose phosphate pathway and glycolysis are distinct, they involve three common intermediates, glucose 6-phosphate, glyceraldehyde 3-phosphate, and fructose 6-phosphate, so the two pathways are interconnected. The pentose phosphate pathway consists of eight reactions:1. Conversion glucose 6-phosphate to D-glucono-1,5-lactone 6-phosphate, with the formation of NADPH; 2. Conversion of D-glucono-1,5-lactone 6-phosphate to 6-phospho-D-gluconate; 3. Conversion of 6-phospho-D-gluconate to ribulose 5-phosphate, with the formation of NADPH; 4. Conversion of ribulose 5-phosphate to xylulose 5-phosphate; 5. Conversion of ribulose 5-phosphate to ribose 5-phosphate; 6. Rearrangement of ribose 5-phosphate and xylulose 5-phosphate to form sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate; 7. Rearrangement of sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate to form erythrose 4-phosphate and fructose 6-phosphate; and 8. Rearrangement of xylulose 5-phosphate and erythrose 4-phosphate to form glyceraldehyde 3-phosphate and fructose-6-phosphate. The oxidative branch of the pentose phosphate pathway, reactions 1-3, generates NADPH and pentose 5-phosphate. The non-oxidative branch of the pathway, reactions 4-8, converts pentose 5-phosphate to other sugars. The overall pathway can operate to generate only NADPH (glucose 6-phosphate is converted to pentose 5-phosphates, which are directed to the synthesis of fructose 6-phosphate and glyceraldehyde 3-phosphate, which in turn are converted back to glucose 6-phosphate). The reactions of the non-oxidative branch can operate to generate net amounts of ribose 5-phosphate with no production of NADPH. Net flux through this network of reactions appears to depend on the metabolic state of the cell and the nature of the biosynthetic reactions underway (Casazza and Veech 1987). G6PD, the enzyme that catalyzes the first reaction of the pathway, is more extensively mutated in human populations than any other enzyme, pehaps because these mutant alleles confer malaria resistance (Luzzatto and Afolayan 1968). Mutations affecting other parts of the pathway are rare, though several have been described and studies of their effects have contributed to our understanding of the normal flux of metabolites through this network of reactions (Wamelink et al. 2008)."
BMGC_PW0027,BMG_PW0050,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of histidine, an essential amino acid which can act as either a proton donor or a proton acceptor. While the synthesis and degradation pathways of histidine are present in microorganisms, histidine can be acted upon by eukaryotic enzymes. Histidine is the precursor of histamine, is involved in immune responses and also acts as a neurotransmitter. [GO:0006547, KEGG:00340, OneLook:www.onelook.com, SMP:00044]",,
BMGC_PW0028,BMG_PW0051,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of tyrosine - a non-essential amino acid produced from phenylalanine and a precursor of thyroid hormones, catecholamines and melanin. Along with phenylalanine and tryptophan, it is one of the three aromatic amino acids. [GO:0006570, http://en.wikipedia.org/wiki/Tyrosine wikipedia, KEGG:00350, SMP:00006]",,
BMGC_PW0029,BMG_PW0052,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of phenylalanine, an essential amino acid. Along with tyrosine and tryptophan, it is one of the three aromatic amino acids. [GO:0006558, KEGG:00360, OneLook:www.onelook.com, Reactome:R-HSA-8964208]",,"The first reaction in this pathway converts phenylalanine to tyrosine, coupled to the conversion of tetrahydrobiopterin to 4a-hydroxytetrahydrobiopterin, catalyzed by phenylalanine hydroxylase. Deficiencies in this enzyme are responsible for the commonest form of phenylketonuria (PKU) in humans. This reaction functions both as the first step in the pathway by which the body disposes of excess phenylalanine, and as a source of the amino acid tyrosine. The next two reactions are responsible for the regeneration of tetrahydrobiopterin from 4a-hydroxytetrahydrobiopterin (Blau et al. 2001)."
BMGC_PW0030,BMG_PW0053,"Those metabolic reactions that are involved in the synthesis, utilization and/or degradation of tryptophan - a dietary essential amino acid and precursor for several important compounds. Along with phenylalanine and tyrosine, it is one of the three aromatic amino acids. [GO:0006568, http://en.wikipedia.org/wiki/Tryptophan wikipedia, KEGG:00380, SMP:00063]",,
BMGC_PW0031,BMG_PW0054,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of nucleotide sugars. Nucleotide sugars are glycosyl donors usually classified depending on the type of the nucleoside forming them. Several are used in animals and many others can be found in plants and bacteria. [InHouse:PW_dictionary, KEGG:map00520]",,
BMGC_PW0032,BMG_PW0057,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of fatty acids - any long-chain monobasic organic acid. [GO:0006631, KEGG:map00071, Reactome:R-HSA-8978868, SMP:00051]",,"The synthesis and breakdown of fatty acids are a central part of human energy metabolism, and the eicosanoid class of fatty acid derivatives regulate diverse processes in the body (Vance & Vance 2008 - URL). Processes annotated in this module include the synthesis of fatty acids from acetyl-CoA, mitochondrial and peroxisomal breakdown of fatty acids, and the metabolism of eicosanoids and related molecules."
BMGC_PW0033,BMG_PW0058,"Those signaling pathways that are involved in or mediate the various aspects of nervous system and/or brain function. [GO:0023041, Reactome:R-HSA-112316]",,"The human brain contains at least 100 billion neurons, each with the ability to influence many other cells. Clearly, highly sophisticated and efficient mechanisms are needed to enable communication among this astronomical number of elements. This communication occurs across synapses, the functional connection between neurons. Synapses can be divided into two general classes: electrical synapses and chemical synapses. Electrical synapses permit direct, passive flow of electrical current from one neuron to another. The current flows through gap junctions, specialized membrane channels that connect the two cells. Chemical synapses enable cell-to-cell communication using neurotransmitter release. Neurotransmitters are chemical agents released by presynaptic neurons that trigger a secondary current flow in postsynaptic neurons by activating specific receptor molecules. Neurotransmitter secretion is triggered by the influx of Ca2+ through voltage-gated channels, which gives rise to a transient increase in Ca2+ concentration within the presynaptic terminal. The rise in Ca2+ concentration causes synaptic vesicles (the presynaptic organelles that store neurotransmitters) to fuse with the presynaptic plasma membrane and release their contents into the space between the pre- and postsynaptic cells."
BMGC_PW0034,BMG_PW0059,"Long-term potentiation (LTP) is a strengthening of the synapse that can last from hours to days and months. It is thought to underlie information storage and constitute the cellular basis of learning and memory. LTP engages numerous cascades of events on either side of the synapse and is accompanied by changes in gene expression. [Dorland's:www.onelook.com, GO:0060291, KEGG:map04720, Reactome:R-HSA-9620244]","Hippocampal long-term potentiation (LTP), a long-lasting increase in synaptic efficacy, is the molecular basis for learning and memory. Tetanic stimulation of afferents in the CA1 region of the hippocampus induces glutamate release and activation of glutamate receptors in dendritic spines. A large increase in [Ca2+]i resulting from influx through NMDA receptors leads to constitutive activation of CaM kinase II (CaM KII) . Constitutively active CaM kinase II phosphorylates AMPA receptors, resulting in potentiation of the ionic conductance of AMPA receptors. Early-phase LTP (E-LTP) expression is due, in part, to this phosphorylation of the AMPA receptor. It is hypothesized that postsynaptic Ca2+ increases generated through NMDA receptors activate several signal transduction pathways including the Erk/MAP kinase and cAMP regulatory pathways. The convergence of these pathways at the level of the CREB/CRE transcriptional pathway may increase expression of a family of genes required for late-phase LTP (L-LTP).","In long-term potentiation (LTP), involved in learning and memory, a brief period of synaptic activity induces a lasting increase in the strength of the synapse. LTP is initiated by NMDA receptor-mediated activation of calcium/calmodulin-dependent protein kinase II (CaMKII), followed by binding of CaMKII to the NMDA receptor and CaMKII-mediated phosphorylation of AMPA receptor subunits (reviewed by Lisman et al. 2012 and Luscher and Malenka 2012)."
BMGC_PW0035,BMG_PW0060,"Long term depression is a weakening of a synapse that lasts hours to days. It results from either strong synaptic stimulation (as in the cerebellum) or to weak synaptic stimulation (as in the hippocampus), and engages several cascades. [GO:0060292, KEGG:map04730, OneLook:www.onelook.com]","Cerebellar long-term depression (LTD), thought to be a molecular and cellular basis for cerebellar learning, is a process involving a decrease in the synaptic strength between parallel fiber (PF) and Purkinje cells (PCs) induced by the conjunctive activation of PFs and climbing fiber (CF). Multiple signal transduction pathways have been shown to be involved in this process. Activation of PFs terminating on spines in dendritic branchlets leads to glutamate release and activation of both AMPA and mGluRs. Activation of CFs, which make multiple synaptic contacts on proximal dendrites, also via AMPA receptors, opens voltage-gated calcium channels (VGCCs) and causes a generalized influx of calcium. These cellular signals, generated from two different synaptic origins, trigger a cascade of events culminating in a phosphorylation-dependent, long-term reduction in AMPA receptor sensitivity at the PF-PC synapse. This may take place either through receptor internalization and/or through receptor desensitization.",
BMGC_PW0036,BMG_PW0061,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of ascorbate and aldarate, as depicted in the KEGG diagram. [KEGG:map00053, OneLook:www.onelook.com]",,
BMGC_PW0037,BMG_PW0062,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glyoxylate and dicarboxylate, as depicted in the KEGG diagram. [KEGG:map00630]",,
BMGC_PW0038,BMG_PW0063,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of propanoate - any salt or ester of propanoic or propionic acid. Several propanoates are used in the food industry. [GO:0019541, http://dl.clackamas.cc.or.us/ch106-04/nomencla1.htm Web, KEGG:map00640, OneLook:www.onelook.com, SMP:00016]",,
BMGC_PW0039,BMG_PW0064,"Those reactions involved in the synthesis, utilization and/or degradation of butanoate - an ester or salt of n-butyric acid. Various butanoates are used as ingredients in flavoring and perfumery. [GO:0019605, KEGG:map00650, OneLook:www.onelook.com, SMP:00073]",,
BMGC_PW0040,BMG_PW0066,"Those reactions involved in carbon dioxide fixation - the reductive carboxylate cycle (CO2 fixation) - the conversion of atmospheric carbon dioxide to organic carbon compounds, as in photosynthesis. [KEGG:map00720, OneLook:www.onelook.com]",,
BMGC_PW0041,BMG_PW0067,"Those pathways used by methanotrophs and the methanogens that metabolize methane as the sole carbon source or as a byproduct. [GO:0015947, KEGG:map00680, OneLook:www.onelook.com]",,
BMGC_PW0042,BMG_PW0068,"Those metabolic reactions involved in the synthesis, utilization or degradation of ketone bodies. The chemicals acetoacetate, acetone and beta-hydroxybutyrate are collectively known as ketone bodies, although only the first two are ketones. They provide fuel for heart and skeletal muscle and for the brain during starvation. Excessive accumulation of these acidic chemicals leads to dangerous diabetic conditions known as ketoacidosis. [GO:0046950, KEGG:map00072, MCW_Libraries:QU4_V876f_2008, OneLook:www.onelook.com, Reactome:R-HSA-74182, SMP:00071]",,"Acetoacetate, beta-hydroxybutyrate, and acetone collectively are called ketone bodies. The first two are synthesized from acetyl-CoA, in the mitochondria of liver cells; acetone is formed by spontaneous decarboxylation of acetoacetate. Ketone body synthesis in liver is effectively irreversible because the enzyme that catalyzes the conversion of acetoacetate to acetoacetyl-CoA is not present in liver cells. Ketone bodies, unlike fatty acids and triglycerides, are water-soluble. They are exported from the liver, and are taken up by other tissues, notably brain and skeletal and cardiac muscle. There, they are broken down to acetyl-CoA which is oxidized via the TCA cycle to yield energy. In a normal person, this pathway of ketone body synthesis and utilization is most active during extended periods of fasting. Under these conditions, mobilization and breakdown of stored fatty acids generates abundant acetyl-CoA acetyl-CoA in liver cells for synthesis of ketone bodies, and their utilization in other tissues minimizes the demand of these tissues for glucose (Sass 2011)."
BMGC_PW0043,BMG_PW0069,"Those metabolic reactions involved in the synthesis of C21-steroid hormones. Pregnenolone, the first C21 steroid derived from cholesterol, and progesterone, to which pregnenolone can be converted, provide the starting materials for the biosynthesis of C21, C19 and C18 steroid hormones. The C21 class includes glucocorticoids such as cortisol and mineralocorticoids such as aldosterone. Glucocorticoids and mineralocorticoids are collectively referred to as corticosteroids. [GO:0006700, KEGG:map00140, PMID:17926129]","Steroid hormones derived from cholesterol are a class of biologically active compounds in vertebrates. The cholesterol side-chain cleavage enzyme CYP11A1 catalyzes conversion of cholesterol, a C27 compound, to the first C21 steroid, pregnenolone, which is converted by a bifunctional enzyme complex to the gestagen hormone, progesterone [MD:M00107]. Pregnenolone and progesterone are the starting materials for the three groups of steroids: C21 steroids of glucocorticoids and mineralocorticoids, C19 steroids of androgens, and C18 steroids of estrogens. (i) Progesterone is converted by hydroxylations at carbons 21 and 11 to corticosterone, which is further modified by hydroxylation and oxydoreduction at carbon 18 to yield aldosterone, a mineralcorticoid [MD:M00108]. Cortisol, the main glucocorticoid, is formed from 17alpha-hydroxyprogesterone with 11-deoxycortisol as an intermediate [MD:M00109]. (ii) Male hormone testosterone is formed from pregnenolone by two pathways, delta5 pathway via dehydroepiandrosterone and delta4 pathway via androstenedione [MD:M00110]. The enzyme CYP17A1 is responsible for the 17,20 lyase and 17alpha-hydroxylase activities in respective pathways. (iii) Female hormones estrone and estradiol are formed from testosterone and 4-androstene-3,17-dione by oxidative removal of the C19 methyl group and subsequent aromatization of ring A. In addition to these three groups, recent studies show that there is another group, termed neurosteroids, synthesized in the brain rather than the peripheral endocrine gland.",
BMGC_PW0044,BMG_PW0070,"Those metabolic reactions involved in the degradation of valine, leucine and isoleucine - the three dietary-essential branched amino acids. [GO:0009083, KEGG:00280, OneLook:www.onelook.com, Reactome:R-HSA-70895, SMP:00032]",,"The branched-chain amino acids, leucine, isoleucine, and valine, are all essential amino acids (i.e., ones required in the diet). They are major constituents of muscle protein. The breakdown of these amino acids starts with two common steps catalyzed by enzymes that act on all three amino acids: reversible transamination by branched-chain amino acid aminotransferase, and irreversible oxidative decarboxylation by the branched-chain ketoacid dehydrogenase complex. Isovaleryl-CoA is produced from leucine by these two reactions, alpha-methylbutyryl-CoA from isoleucine, and isobutyryl-CoA from valine. These acyl-CoA's undergo dehydrogenation, catalyzed by three different but related enzymes, and the breakdown pathways then diverge. Leucine is ultimately converted to acetyl-CoA and acetoacetate; isoleucine to acetyl-CoA and succinyl-CoA; and valine to succinyl-CoA. Under fasting conditions, substantial amounts of all three amino acids are generated by protein breakdown. In muscle, the final products of leucine, isoleucine, and valine catabolism can be fully oxidized via the citric acid cycle; in liver they can be directed toward the synthesis of ketone bodies (acetoacetate and acetyl-CoA) and glucose (succinyl-CoA) (Neinast et al. 2019)."
BMGC_PW0045,BMG_PW0072,"Those metabolic reactions involved in the degradation of lysine. In mammals, lysine is metabolized to acetyl-CoA. A derivative of lysine, allysine, is used in the production of elastin and collagen. [GO:0006554, https://en.wikipedia.org/wiki/Lysine wikipedia, KEGG:00310, Reactome:R-HSA-71064, SMP:00037]",,"In humans, most catabolism of L-lysine normally proceeds via a sequence of seven reactions which feeds into the pathway for fatty acid catabolism. In the first two reactions, catalyzed by a single enzyme complex, lysine is combined with alpha-ketoglutarate to form saccharopine, which in turn is cleaved and oxidized to yield glutamate and alpha-ketoadipic semialdehyde. The latter molecule is further oxidized to alpha-ketoadipate. Alpha-ketoadipate is oxidatively decarboxylated by the alpha-ketoglutarate dehydrogenase complex (the same enzyme complex responsible for the conversion of alpha-ketoglutarate to succinyl-CoA in the citric acid cycle), yielding glutaryl-CoA. Glutaryl-CoA is converted to crotonyl-CoA, crotonyl-CoA is converted to beta-hydroxybutyryl-CoA, and beta-hydroxybutyryl-CoA is converted to acetoacetyl-CoA. The products of lysine catabolism are thus exclusively ketogenic; i.e., under starvation conditions they can be used for the synthesis of ketone bodies, beta-hydroxybutyrate and acetoacetate, but not for the net synthesis of glucose (Cox 2001; Goodman and Freeman 2001)."
BMGC_PW0046,BMG_PW0073,"Those metabolic reactions involved in the biosynthesis of lysine - an essential amino acid. In plants and bacteria it is synthesized from aspartate. [GO:0009085, https://en.wikipedia.org/wiki/Lysine wikipedia, KEGG:00300]",,
BMGC_PW0047,BMG_PW0075,"The series of metabolic reactions, occurring in the liver, by which the ammonia derived from the breakdown of amino acids combines with carbon dioxide to form urea. [GO:0000050, PMID:12055339, Reactome:R-HSA-70635, SMP:00059]",,"The urea cycle yields urea, the major form in which excess nitrogen is excreted from the human body, and the amino acid arginine (Brusilow and Horwich 2001). It consists of four reactions: that of ornithine and carbamoyl phosphate to form citrulline, of citrulline and aspartate to form argininosuccinate, the cleavage of argininosuccinate to yield fumarate and arginine, and the cleavage of arginine to yield urea and re-form ornithine. The carbamoyl phosphate consumed in this cycle is synthesized in the mitochondria from bicarbonate and ammonia, and this synthesis in turn is dependent on the presence of N-acetylglutamate, which allosterically activates carbamoyl synthetase I enzyme. The synthesis of N-acetylglutamate is stimulated by high levels of arginine. Increased levels of free amino acids, indicated by elevated arginine levels, thus stimulate urea synthesis. Two enzymes catalyze the hydrolysis of arginine to yield ornithine and urea. Cytosolic ARG1 is the canonical urea cycle enzyme. Mitochondrial ARG2 likewise catalyzes urea production from arginine and may have a substantial sparing effect in patients lacking ARG1 enzyme, so its reaction is annotated here although the role of ARG2 under normal physiological conditions remains unclear."
BMGC_PW0048,BMG_PW0076,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of beta-alanine. Beta-alanine is an amino acid formed in vivo by the degradation of dihydrouracil and carnosine. Beta-alanine is not used in the synthesis of proteins but is a component of natural peptides, vitamins such as vitamin B5 and of coenzyme A. A rare genetic disorder, hyper-beta-alaninemia, has been reported. [GO:0019482, KEGG:map00410, Onelook:www.onelook.com, SMP:00007]",,
BMGC_PW0049,BMG_PW0085,"The series of events, collectively known as the cell cycle, that underlie the replication of the genome and the segregation of chromosomes into daughter cells. The cycle begins with a diploid cell and produces two identical diploid cells. [GO:0000278, Handbook:Essential_Cell_Biology, KEGG:map04110, Reactome:R-HSA-69278]","Mitotic cell cycle progression is accomplished through a reproducible sequence of events, DNA replication (S phase) and mitosis (M phase) separated temporally by gaps known as G1 and G2 phases. Cyclin-dependent kinases (CDKs) are key regulatory enzymes, each consisting of a catalytic CDK subunit and an activating cyclin subunit. CDKs regulate the cell's progression through the phases of the cell cycle by modulating the activity of key substrates. Downstream targets of CDKs include transcription factor E2F and its regulator Rb. Precise activation and inactivation of CDKs at specific points in the cell cycle are required for orderly cell division. Cyclin-CDK inhibitors (CKIs), such as p16Ink4a, p15Ink4b, p27Kip1, and p21Cip1, are involved in the negative regulation of CDK activities, thus providing a pathway through which the cell cycle is negatively regulated.              Eukaryotic cells respond to DNA damage by activating signaling pathways that promote cell cycle arrest and DNA repair. In response to DNA damage, the checkpoint kinase ATM phosphorylates and activates Chk2, which in turn directly phosphorylates and activates p53 tumor suppressor protein. p53 and its transcriptional targets play an important role in both G1 and G2 checkpoints. ATR-Chk1-mediated protein degradation of Cdc25A protein phosphatase is also a mechanism conferring intra-S-phase checkpoint activation.","The events of replication of the genome and the subsequent segregation of chromosomes into daughter cells make up the cell cycle. DNA replication is carried out during a discrete temporal period known as the S (synthesis)-phase, and chromosome segregation occurs during a massive reorganization of cellular architecture at mitosis. Two gap-phases separate these cell cycle events: G1 between mitosis and S-phase, and G2 between S-phase and mitosis. Cells can exit the cell cycle for a period and enter a quiescent state known as G0, or terminally differentiate into cells that will not divide again, but undergo morphological development to carry out the wide variety of specialized functions of individual tissues. A family of protein serine/threonine kinases known as the cyclin-dependent kinases (CDKs) controls progression through the cell cycle. As the name suggests, the kinase activity of the catalytic subunits is dependent on binding to cyclin partners, and control of cyclin abundance is one of several mechanisms by which CDK activity is regulated throughout the cell cycle. A complex network of regulatory processes determines whether a quiescent cell (in G0 or early G1) will leave this state and initiate the processes to replicate its chromosomal DNA and divide. This regulation, during the Mitotic G1-G1/S phases of the cell cycle, centers on transcriptional regulation by the DREAM complex, with major roles for D and E type cyclin proteins. Chromosomal DNA synthesis occurs in the S phase, or the synthesis phase, of the cell cycle. The cell duplicates its hereditary material, and two copies of each chromosome are formed. A key aspect of the regulation of DNA replication is the assembly and modification of a pre-replication complex assembled on ORC proteins. Mitotic G2-G2/M phases encompass the interval between the completion of DNA synthesis and the beginning of mitosis. During G2, the cytoplasmic content of the cell increases. At G2/M transition, duplicated centrosomes mature and separate and CDK1:cyclin B complexes become active, setting the stage for spindle assembly and chromosome condensation at the start of mitotic M phase. Mitosis, or M phase, results in the generation of two daughter cells each with a complete diploid set of chromosomes. Events of the M/G1 transition, progression out of mitosis and division of the cell into two daughters (cytokinesis) are regulated by the Anaphase Promoting Complex. The Anaphase Promoting Complex or Cyclosome (APC/C) plays additional roles in regulation of the mitotic cell cycle, insuring the appropriate length of the G1 phase. The APC/C itself is regulated by phosphorylation and interactions with checkpoint proteins."
BMGC_PW0050,BMG_PW0086,"The series of events underlying the progression of the early cell cycle into the G phase and under the control of D-type cyclins together with Cdk4 and Cdk6. The formation of the pre-initiation replication complex takes place during this phase. [GO:0000080, Reactome:R-HSA-69236]",,"Early cell cycle progression in G1 is under the control of the D-type cyclins together with Cdk4 and Cdk6. An important target for these CDKs is the Retinoblastoma (Rb) protein, which when phosphorylated promotes cell cycle progression by releasing E2F transcription factors that transactivate several important genes for later cell cycle events. The formation of Cyclin D - Cdk4/6 complexes is promoted by two proteins, p21Cip1/Waf1 and p27kip1, and their activity can be inhibited by the binding of several small CDK-inhibitory proteins (CKIs): p15INK4B, p16INK4A, p18INK4C and p19INK4D."
BMGC_PW0051,BMG_PW0087,"The series of events underlying the transition from G1 into S phase and under the control of Cyclin E/A - Cdk2 and cyclin D-Cdk4/Cdk6 complexes and their regulators. Genetic alterations of this important transition point are frequent in human cancers. [GO:0000082, PMID:10919634, PMID:12200872, PMID:16236519, Reactome:R-HSA-69206]",,"Cyclin E - Cdk2 complexes control the transition from G1 into S-phase. In this case, the binding of p21Cip1/Waf1 or p27kip1 is inhibitory. Important substrates for Cyclin E - Cdk2 complexes include proteins involved in the initiation of DNA replication. The two Cyclin E proteins are subjected to ubiquitin-dependent proteolysis, under the control of an E3 ubiquitin ligase known as the SCF. Cyclin A - Cdk2 complexes, which are also regulated by p21Cip1/Waf1 and p27kip1, are likely to be important for continued DNA synthesis, and progression into G2. An additional level of control of Cdk2 is reversible phosphorylation of Threonine-14 (T14) and Tyrosine-15 (Y15), catalyzed by the Wee1 and Myt1 kinases, and dephosphorylation by the three Cdc25 phosphatases, Cdc25A, B and C."
BMGC_PW0052,BMG_PW0088,"The series of events underlying duplication of the hereditary material of the cell, forming two copies of each chromosome. [GO:0000084, Reactome:R-HSA-69242]",,"DNA synthesis occurs in the S phase, or the synthesis phase, of the cell cycle. The cell duplicates its hereditary material, and two copies of the chromosome are formed. As DNA replication continues, the E type cyclins shared by the G1 and S phases, are destroyed and the levels of the mitotic cyclins rise."
BMGC_PW0053,BMG_PW0089,"The series of events underlying the second 'gap' phase of the mitotic cell cycle - an interval between the completion of DNA synthesis and the beginning of mitosis, during which protein synthesis occurs. [GO:0000085, Reactome:R-HSA-68911]",,"This is one of two 'gap' phases in the standard eukaryotic mitotic cell cycle. It is the interval between the completion of DNA synthesis and the beginning of mitosis. Protein synthesis occurs in this phase, following DNA replication in the S phase. This is the time when the cell stockpiles on the cytoplasmic contents, before mitosis and cytokinesis occur (Mitchison 2003, Kaldis 2016)."
BMGC_PW0054,BMG_PW0090,"The series of events underlying the transition from the G2 phase into mitosis. [GO:0000086, Reactome:R-HSA-69275]",,"Together with two B-type cyclins, CCNB1 and CCNB2, Cdc2 (CDK1) regulates the transition from G2 into mitosis. CDK1 can also form complexes with Cyclin A (CCNA1 and CCNA3). CDK1 complexes with A and B type cyclins are activated by dephosphorylation of CDK1 threonine residue T14 and tyrosine residue Y15. Cyclin A:CDK1 and Cyclin B:CDK1 complexes phosphorylate several proteins involved in mitotic spindle formation and function, the breakdown of the nuclear envelope, and chromosome condensation that is necessary for the ~2 meters of DNA to be segregated at mitosis (Nigg 1998, Nilsson and Hoffmann 2000, Salaun et al. 2008, Fisher et al. 2012)."
BMGC_PW0055,BMG_PW0091,"The series of events underlying mitosis (M phase), in turn comprised of several phases, involving nuclear division and cytokinesis and resulting in the formation of two daughter cells. [GO:0000279, Reactome:R-HSA-68886]",,"Mitosis, or the M phase, involves nuclear division and cytokinesis, where two identical daughter cells are produced. Mitosis involves prophase, prometaphase, metaphase, anaphase, and telophase. Finally, cytokinesis leads to cell division. The phase between two M phases is called the interphase; it encompasses the G1, S, and G2 phases of the cell cycle."
BMGC_PW0056,BMG_PW0092,The series of events underlying progression out of mitosis and division into two daughter cells. It requires the inactivation of cyclinB-cdc2 by ubiquitin-dependent proteolysis. [Reactome:R-HSA-68874],,
BMGC_PW0057,BMG_PW0093,"Those pathways involved in the control of cell cycle progression as well as its precision and fidelity. [GO:0000075, PMID:14644189, Reactome:R-HSA-69620]",,"A hallmark of the human cell cycle in normal somatic cells is its precision. This remarkable fidelity is achieved by a number of signal transduction pathways, known as checkpoints, which monitor cell cycle progression ensuring an interdependency of S-phase and mitosis, the integrity of the genome and the fidelity of chromosome segregation. Checkpoints are layers of control that act to delay CDK activation when defects in the division program occur. As the CDKs functioning at different points in the cell cycle are regulated by different means, the various checkpoints differ in the biochemical mechanisms by which they elicit their effect. However, all checkpoints share a common hierarchy of a sensor, signal transducers, and effectors that interact with the CDKs. The stability of the genome in somatic cells contrasts to the almost universal genomic instability of tumor cells. There are a number of documented genetic lesions in checkpoint genes, or in cell cycle genes themselves, which result either directly in cancer or in a predisposition to certain cancer types. Indeed, restraint over cell cycle progression and failure to monitor genome integrity are likely prerequisites for the molecular evolution required for the development of a tumor. Perhaps most notable amongst these is the p53 tumor suppressor gene, which is mutated in >50% of human tumors. Thus, the importance of the checkpoint pathways to human biology is clear."
BMGC_PW0058,BMG_PW0094,"Those pathways of DNA damage response that occur during the G1 phase. [InHouse:PW_dictionary, Reactome:R-HSA-69615]",,"In the G1 phase there are two types of DNA damage responses, the p53-dependent and the p53-independent pathways. The p53-dependent responses inhibit CDKs through the up-regulation of genes encoding CKIs mediated by the p53 protein, whereas the p53-independent mechanisms inhibit CDKs through the inhibitory T14Y15 phosphorylation of Cdk2. Failure of DNA damage checkpoints in G1 leads to mutagenic replication of damaged templates and other replication defects."
BMGC_PW0059,BMG_PW0095,"Those pathways that assure the genome is replicated only once per cell cycle. The checkpoints control for damaged and un-replicated DNA. [InHouse:PW_dictionary, Reactome:R-HSA-69481]",,"G2/M checkpoints include the checks for damaged DNA, unreplicated DNA, and checks that ensure that the genome is replicated once and only once per cell cycle. If cells pass these checkpoints, they follow normal transition to the M phase. However, if any of these checkpoints fail, mitotic entry is prevented by specific G2/M checkpoint events. The G2/M checkpoints can fail due to the presence of unreplicated DNA or damaged DNA. In such instances, the cyclin-dependent kinase, Cdc2(Cdk1), is maintained in its inactive, phosphorylated state, and mitotic entry is prevented. Events that ensure that origins of DNA replication fire once and only once per cell cycle are also an example of a G2/M checkpoint. In the event of high levels of DNA damage, the cells may also be directed to undergo apopotosis (not covered)."
BMGC_PW0060,BMG_PW0096,"The pathway prevents cells with mis-aligned chromosomes from dividing. Defects of kinetochore function activate checkpoint proteins to initiate a cascade of events that eventually prevent separation of sister chromatids. [GO:0071174, InHouse:PW_dictionary, Reactome:R-HSA-69618]",,"The mitotic checkpoint or spindle assembly checkpoint is an evolutionarily conserved mechanism that ensures that cells with misaligned chromosomes do not exit mitosis and divide to form aneuploid cells. As chromosome attachment to the spindle microtubules is a stochastic process, not all chromosomes achieve alignment at the spindle equator at the same time. It is therefore essential that even a single unaligned chromosome can prevent the onset of anaphase. The ability of the checkpoint to monitor the status of chromosome alignment is achieved by assigning checkpoint proteins to the kinetochore, a macromolecular complex that resides at centromeres of chromosomes that establishes connections with spindle microtubules. The checkpoint proteins monitor, in an unknown way, the mechanical activities between kinetochore-associated proteins and microtubules. Defects in mechanical activities at kinetochores activate the resident checkpoint proteins to initiate a signal that is amplified throughout the cell that ultimately prevents the activation of the proteolytic process that is required for sister chromatid separation and the onset of anaphase. Kinetochores of unaligned chromosomes differ from those of aligned chromosomes in two ways. Kinetochores of aligned chromosomes are saturated with between 20 to 30 microtubules. In addition, poleward directed forces exerted at each sister kinetochore generates tension between them. Unaligned kinetochores on the other hand, are not saturated with microtubules and are not under tension. The mitotic checkpoint detects the presence of unattached kinetochores rather than monitoring for the presence of attached kinetochores. Consequently, unattached kinetochores emit an inhibitory signal that inhibits the biochemical events that are required to initiate the onset of anaphase. The mechanism by which this inhibitory signal is generated at unattached kinetochores has not precisely been determined but the signal is generated as a result of the lack of microtubule occupancy and kinetochore tension. A single unattached kinetochore is capable of preventing cells from exiting mitosis. The mitotic checkpoint provides a way for a localized defect to affect the global biochemical status of the cell. In principle, the signal that is generated at an unattached kinetochore diffuses throughout the cell to affect its target. There are currently two models for how this is achieved. One model is based on the observation that the Mad2 checkpoint protein binds and is rapidly released from unattached kinetochores. The kinetochore is believed to act as a catalyst that converts Mad2 into an inhibitory state that diffuses throughout the cell upon its release from the kinetochore. A second model proposes that the signal is amplified by a kinase cascade much like a conventional signal transduction pathway. This kinase cascade is believed to be comprised of the checkpoint kinases, hBUBR1, hBUB1, hMPS1."
BMGC_PW0061,BMG_PW0098,"The pathways involved in the repair of damaged DNA. The damage can involve mismatched or damaged bases, distortion of the helix or breaks in the DNA double strand. Repair of DNA lesions along with the upstream lesion detection and signaling its presence are collectively known as the DNA damage response. [GO:0006281, PMID:19847258, Reactome:R-HSA-73894]",,
BMGC_PW0062,BMG_PW0099,"The pathways governing and/or regulating DNA transcription and gene expression. DNA transcription into coding and non-coding RNA is accomplished by one prokaryotic and several eukaryotic RNA polymerases. Transcription-coupled repair handles DNA lesions that interfere with the progression of RNA polymerases. Splicing of nascent RNA is thought to be predominantly co-transcriptional. Signaling pathways mediated by various transcription factors are involved in the regulation of gene expression. [GO:0006351, http://en.wikipedia.org/wiki/Transcription wikipedia, Reactome:R-HSA-212436]",,"OVERVIEW OF TRANSCRIPTION REGULATION: Detailed studies of gene transcription regulation in a wide variety of eukaryotic systems has revealed the general principles and mechanisms by which cell- or tissue-specific regulation of differential gene transcription is mediated (reviewed in Naar, 2001. Kadonaga, 2004, Maston, 2006, Barolo, 2002; Roeder, 2005, Rosenfeld, 2006). Of the three major classes of DNA polymerase involved in eukaryotic gene transcription, Polymerase II generally regulates protein-encoding genes. Figure 1 shows a diagram of the various components involved in cell-specific regulation of Pol-II gene transcription. Core Promoter: Pol II-regulated genes typically have a Core Promoter where Pol II and a variety of general factors bind to specific DNA motifs: i: the TATA box (TATA DNA sequence), which is bound by the ""TATA-binding protein"" (TBP). ii: the Initiator motif (INR), where Pol II and certain other core factors bind, is present in many Pol II-regulated genes. iii: the Downstream Promoter Element (DPE), which is present in a subset of Pol II genes, and where additional core factors bind. The core promoter binding factors are generally ubiquitously expressed, although there are exceptions to this. Proximal Promoter: immediately upstream (5') of the core promoter, Pol II target genes often have a Proximal Promoter region that spans up to 500 base pairs (b.p.), or even to 1000 b.p.. This region contains a number of functional DNA binding sites for a specific set of transcription activator (TA) and transcription repressor (TR) proteins. These TA and TR factors are generally cell- or tissue-specific in expression, rather than ubiquitous, so that the presence of their cognate binding sites in the proximal promoter region programs cell- or tissue-specific expression of the target gene, perhaps in conjunction with TA and TR complexes bound in distal enhancer regions. Distal Enhancer(s): many or most Pol II regulated genes in higher eukaryotes have one or more distal Enhancer regions which are essential for proper regulation of the gene, often in a cell or tissue-specific pattern. Like the proximal promoter region, each of the distal enhancer regions typically contain a cluster of binding sites for specific TA and/or TR DNA-binding factors, rather than just a single site. Enhancers generally have three defining characteristics: i: They can be located very long distances from the promoter of the target gene they regulate, sometimes as far as 100 Kb, or more. ii: They can be either upstream (5') or downstream (3') of the target gene, including within introns of that gene. iii: They can function in either orientation in the DNA. Combinatorial mechanisms of transcription regulation: The specific combination of TA and TR binding sites within the proximal promoter and/or distal enhancer(s) provides a ""combinatorial transcription code"" that mediates cell- or tissue-specific expression of the associated target gene. Each promoter or enhancer region mediates expression in a specific subset of the overall expression pattern. In at least some cases, each enhancer region functions completely independently of the others, so that the overall expression pattern is a linear combination of the expression patterns of each of the enhancer modules. Co-Activator and Co-Repressor Complexes: DNA-bound TA and TR proteins typically recruit the assembly of specific Co-Activator (Co-A) and Co-Repressor (Co-R) Complexes, respectively, which are essential for regulating target gene transcription. Both Co-A's and Co-R's are multi-protein complexes that contain several specific protein components. Co-Activator complexes generally contain at lease one component protein that has Histone Acetyl Transferase (HAT) enzymatic activity. This functions to acetylate Histones and/or other chromatin-associated factors, which typically increases that transcription activation of the target gene. By contrast, Co-Repressor complexes generally contain at lease one component protein that has Histone De-Acetylase (HDAC) enzymatic activity. This functions to de-acetylate Histones and/or other chromatin-associated factors. This typically increases the transcription repression of the target gene. Adaptor (Mediator) complexes: In addition to the co-activator complexes that assemble on particular cell-specific TA factors, - there are at least two additional transcriptional co-activator complexes common to most cells. One of these is the Mediator complex, which functions as an ""adaptor"" complex that bridges between the tissue-specific co-activator complexes assembled in the proximal promoter (or distal enhancers). The human Mediator complex has been shown to contain at least 19 protein distinct components. Different combinations of these co-activator proteins are also found to be components of specific transcription Co-Activator complexes, such as the DRIP, TRAP and ARC complexes described below. TBP/TAF complex: Another large Co-A complex is the ""TBP-associated factors"" (TAFs) that assemble on TBP (TATA-Binding Protein), which is bound to the TATA box present in many promoters. There are at least 23 human TAF proteins that have been identified. Many of these are ubiquitously expressed, but TAFs can also be expressed in a cell or tissue-specific pattern. Specific Coactivator Complexes for DNA-binding Transcription Factors. A number of specific co-activator complexes for DNA-binding transcription factors have been identified, including DRIP, TRAP, and ARC (reviewed in Bourbon, 2004, Blazek, 2005, Conaway, 2005, and Malik, 2005). The DRIP co-activator complex was originally identified and named as a specific complex associated with the Vitamin D Receptor member of the nuclear receptor family of transcription factors (Rachez, 1998). Similarly, the TRAP co-activator complex was originally identified as a complex that associates with the thyroid receptor (Yuan, 1998). It was later determined that all of the components of the DRIP complex are also present in the TRAP complex, and the ARC complex (discussed further below). For example, the DRIP205 and TRAP220 proteins were show to be identical, as were specific pairs of the other components of these complexes (Rachez, 1999). In addition, these various transcription co-activator proteins identified in mammalian cells were found to be the orthologues or homologues of the Mediator (""adaptor"") complex proteins (reviewed in Bourbon, 2004). The Mediator proteins were originally identified in yeast by Kornberg and colleagues, as complexes associated with DNA polymerase (Kelleher, 1990). In higher organisms, Adapter complexes bridge between the basal transcription factors (including Pol II) and tissue-specific transcription factors (TFs) bound to sites within upstream Proximal Promoter regions or distal Enhancer regions (Figure 1). However, many of the Mediator homologues can also be found in complexes associated with specific transcription factors in higher organisms. A unified nomenclature system for these adapter / co-activator proteins now labels them Mediator 1 through Mediator 31 (Bourbon, 2004). For example, the DRIP205 / TRAP220 proteins are now identified as Mediator 1 (Rachez, 1999), based on homology with yeast Mediator 1. Example Pathway: Specific Regulation of Target Genes During Notch Signaling: One well-studied example of cell-specific regulation of gene transcription is selective regulation of target genes during Notch signaling. Notch signaling was first identified in Drosophila, where it has been studied in detail at the genetic, molecular, biochemical and cellular levels (reviewed in Justice, 2002; Bray, 2006; Schweisguth, 2004; Louvri, 2006). In Drosophila, Notch signaling to the nucleus is thought always to be mediated by one specific DNA binding transcription factor, Suppressor of Hairless. In mammals, the homologous genes are called CBF1 (or RBPJkappa), while in worms they are called Lag-1, so that the acronym ""CSL"" has been given to this conserved transcription factor family. There are at least two human CSL homologues, which are now named RBPJ and RBPJL. In Drosophila, Su(H) is known to be bifunctional, in that it represses target gene transcription in the absence of Notch signaling, but activates target genes during Notch signaling. At least some of the mammalian CSL homologues are believed also to be bifunctional, and to mediate target gene repression in the absence of Notch signaling, and activation in the presence of Notch signaling. Notch Co-Activator and Co-Repressor complexes: This repression is mediated by at least one specific co-repressor complexes (Co-R) bound to CSL in the absence of Notch signaling. In Drosophila, this co-repressor complex consists of at least three distinct co-repressor proteins: Hairless, Groucho, and dCtBP (Drosophila C-terminal Binding Protein). Hairless has been show to bind directly to Su(H), and Groucho and dCtBP have been shown to bind directly to Hairless (Barolo, 2002). All three of the co-repressor proteins have been shown to be necessary for proper gene regulation during Notch signaling in vivo (Nagel, 2005). In mammals, the same general pathway and mechanisms are observed, where CSL proteins are bifunctional DNA binding transcription factors (TFs), that bind to Co-Repressor complexes to mediate repression in the absence of Notch signaling, and bind to Co-Activator complexes to mediate activation in the presence of Notch signaling. However, in mammals, there may be multiple co-repressor complexes, rather than the single Hairless co-repressor complex that has been observed in Drosophila. During Notch signaling in all systems, the Notch transmembrane receptor is cleaved and the Notch intracellular domain (NICD) translocates to the nucleus, where it there functions as a specific transcription co-activator for CSL proteins. In the nucleus, NICD replaces the Co-R complex bound to CSL, thus resulting in de-repression of Notch target genes in the nucleus (Figure 2). Once bound to CSL, NICD and CSL proteins recruit an additional co-activator protein, Mastermind, to form a CSL-NICD-Mam ternary co-activator (Co-A) complex. This Co-R complex was initially thought to be sufficient to mediate activation of at least some Notch target genes. However, there now is evidence that still other co-activators and additional DNA-binding transcription factors are required in at least some contexts (reviewed in Barolo, 2002). Thus, CSL is a good example of a bifunctional DNA-binding transcription factor that mediates repression of specific targets genes in one context, but activation of the same targets in another context. This bifunctionality is mediated by the association of specific Co-Repressor complexes vs. specific Co-Activator complexes in different contexts, namely in the absence or presence of Notch signaling."
BMGC_PW0063,BMG_PW0100,"The series of events governing the processes whereby mRNA is translated into a polypeptide chain. Post-translational modifications often accompany the formation of the final, mature protein. Translation involves initiation, elongation and termination steps and is dependent upon the availability of aminoacyl-tRNA and mature ribosomes. [GO:0006412, PMID:23209153, PMID:23677826, Reactome:R-HSA-72766]",,"Protein synthesis is accomplished through the process of translation of an mRNA sequence into a polypeptide chain. This process can be divided into three distinct stages: initiation, elongation and termination. During the initiation phase, the two subunits of the ribosome are brought together to the translation start site on the mRNA where the polypeptide chain is to begin. Extension of the polypeptide chain occurs when a specific aminoacyl-tRNA, as determined by the template mRNA, binds an elongating ribosome. The protein chain is released from the ribosome when any one of three stop codons in the relevant reading frame on the mRNA is reached. Individual reactions at each one of these stages are catalyzed by a number of initiation, elongation and release factors, respectively. Proteins destined for the endoplasmic reticulum (ER) contain a short sequence of hydrophobic amino acid residues (approximately 20 residues) at their N-termini. Upon protrusion of the signal sequence from the translating ribosome, the signal sequence is bound by the cytosolic signal recognition particle (SRP), translation is temporarily halted, and the SRP:nascent peptide:ribosome complex then docks with a SRP receptor complex on the ER membrane. There the nascent peptide:ribosome complex is transferred from the SRP complex to a translocon complex embedded in the ER membrane and reoriented so that the nascent polypeptide protrudes through a pore in the translocon into the ER lumen. Translation now resumes, the signal peptide is cleaved from the polypeptide by signal peptidase as the signal peptide emerges into the ER, and elongation proceeds with the growing polypeptide oriented into the ER lumen. The 13 proteins encoded by the mitochondrial genome are translated within the mitochondrion by mitochondrial ribosomes (mitoribosomes) at the matrix face of the inner mitochondrial membrane. Mitochondrial translation reflects both the bacterial origin of the organelle and subsequent divergent evolution during symbiosis. Mitoribosomes have shorter rRNAs, mitochondria-specific proteins, and rearranged protein positions. Mitochondrial mRNAs have either no untranslated leaders or very short untranslated leaders of 1-3 nucleotides. Translation begins with N-formylmethionine, as in bacteria, and continues with cycles of aminoacyl-tRNA:TUFM:GTP binding, GTP hydrolysis and dissociation of TUFM:GDP. All 13 proteins encoded by the mitochondrial genome are hydrophobic inner membrane proteins which are inserted cotranslationally into the membrane by an interaction with OXA1L. Translation is terminated when MTRF1L:GTP recognizes a UAA or UAG codon at the A-site of the mitoribosome. The translated polypeptide is released and MRRF and GFM2:GTP act to dissociate the 55S ribosome into 28S and 39S subunits."
BMGC_PW0064,BMG_PW0101,"The Raf/Mek/Erk signaling pathway - a Ras activated protein kinase cascade - regulates diverse processes such as cell growth, proliferation and differentiation, in response to cytokines, hormones, growth factors. [GO:0070371, KEGG:map04010, PMID:15035987, PMID:17112607, PMID:17229475, PMID:17306385]","The mitogen-activated protein kinase (MAPK) cascade is a highly conserved module that is involved in various cellular functions, including cell proliferation, differentiation and migration. Mammals express at least four distinctly regulated groups of MAPKs, extracellular signal-related kinases (ERK)-1/2, Jun amino-terminal kinases (JNK1/2/3), p38 proteins (p38alpha/beta/gamma/delta) and ERK5, that are activated by specific MAPKKs: MEK1/2 for ERK1/2, MKK3/6 for the p38, MKK4/7 (JNKK1/2) for the JNKs, and MEK5 for ERK5. Each MAPKK, however, can be activated by more than one MAPKKK, increasing the complexity and diversity of MAPK signalling. Presumably each MAPKKK confers responsiveness to distinct stimuli. For example, activation of ERK1/2 by growth factors depends on the MAPKKK c-Raf, but other MAPKKKs may activate ERK1/2 in response to pro-inflammatory stimuli.","The mitogen activated protein kinases (MAPKs) are a family of conserved protein serine threonine kinases that respond to varied extracellular stimuli to activate intracellular processes including gene expression, metabolism, proliferation, differentiation and apoptosis, among others. The classic MAPK cascades, including the ERK1/2 pathway, the p38 MAPK pathway, the JNK pathway and the ERK5 pathway are characterized by three tiers of sequentially acting, activating kinases (reviewed in Kryiakis and Avruch, 2012; Cargnello and Roux, 2011). The MAPK kinase kinase kinase (MAPKKK), at the top of the cascade, is phosphorylated on serine and threonine residues in response to external stimuli; this phosphorylation often occurs in the context of an interaction between the MAPKKK protein and a member of the RAS/RHO family of small GTP-binding proteins. Activated MAPKKK proteins in turn phosphorylate the dual-specificity MAPK kinase proteins (MAPKK), which ultimately phosphorylate the MAPK proteins in a conserved Thr-X-Tyr motif in the activation loop. Less is known about the activation of the atypical families of MAPKs, which include the ERK3/4 signaling cascade, the ERK7 cascade and the NLK cascade. Although the details are not fully worked out, these MAPK proteins don't appear to be phosphorylated downstream of a 3-tiered kinase system as described above (reviewed in Coulombe and Meloche, 2007; Cargnello and Roux, 2011) . Both conventional and atypical MAPKs are proline-directed serine threonine kinases and, once activated, phosphorylate substrates in the consensus P-X-S/T-P site. Both cytosolic and nuclear targets of MAPK proteins have been identified and upon stimulation, a proportion of the phosphorylated MAPKs relocalize from the cytoplasm to the nucleus. In some cases, nuclear translocation may be accompanied by dimerization, although the relationship between these two events is not fully elaborated (reviewed in Kryiakis and Avruch, 2012; Cargnello and Roux, 2011; Plotnikov et al, 2010)."
BMGC_PW0065,BMG_PW0103,"The apoptotic pathway involving organelles, primarily the mitochondrion and endoplasmic reticulum (ER), and involving the pro- and anti-apoptotic members of the Bcl family of proteins, cytochrome C, formation of the apoptosome and activation of caspases. [GO:0097193, KEGG:map04210, PMID:14744432, Reactome:R-HSA-109606]","Apoptosis is a genetically programmed process for the elimination of damaged or redundant cells by activation of caspases (aspartate-specific cysteine proteases). The onset of apoptosis is controlled by numerous interrelating processes. The 'extrinsic' pathway involves stimulation of members of the tumor necrosis factor (TNF) receptor subfamily, such as TNFRI, CD95/Fas or TRAILR (death receptors), located at the cell surface, by their specific ligands, such as TNF-alpha, FasL or TRAIL, respectively. The 'intrinsic' pathway is activated mainly by non-receptor stimuli, such as DNA damage, ER stress, metabolic stress, UV radiation or growth-factor deprivation. The central event in the 'intrinsic' pathway is the mitochondrial outer membrane permeabilization (MOMP), which leads to the release of cytochrome c. These two pathways converge at the level of effector caspases, such as caspase-3 and caspase-7. The third major pathway is initiated by the constituents of cytotoxic granules (e.g. Perforin and Granzyme B) that are released by CTLs (cytotoxic T-cells) and NK (natural killer) cells. Granzyme B, similarly to the caspases, cleaves its substrates after aspartic acid residues, suggesting that this protease has the ability to activate members of the caspase family directly. It is the balance between the pro-apoptotic and anti-apoptotic signals that eventually determines whether cells will undergo apoptosis, survive or proliferate. TNF family of ligands activates anti-apoptotic or cell-survival signals as well as apoptotic signals. NGF and Interleukin-3 promotes the survival, proliferation and differentiation of neurons or hematopoietic cells, respectively. Withdrawal of these growth factors leads to cell death, as described above.","The intrinsic (Bcl-2 inhibitable or mitochondrial) pathway of apoptosis functions in response to various types of intracellular stress including growth factor withdrawal, DNA damage, unfolding stresses in the endoplasmic reticulum and death receptor stimulation. Following the reception of stress signals, proapoptotic BCL-2 family proteins are activated and subsequently interact with and inactivate antiapoptotic BCL-2 proteins. This interaction leads to the destabilization of the mitochondrial membrane and release of apoptotic factors. These factors induce the caspase proteolytic cascade, chromatin condensation, and DNA fragmentation, ultimately leading to cell death. The key players in the Intrinsic pathway are the Bcl-2 family of proteins that are critical death regulators residing immediately upstream of mitochondria. The Bcl-2 family consists of both anti- and proapoptotic members that possess conserved alpha-helices with sequence conservation clustered in BCL-2 Homology (BH) domains. Proapoptotic members are organized as follows: 1. ""Multidomain"" BAX family proteins such as BAX, BAK etc. that display sequence conservation in their BH1-3 regions. These proteins act downstream in mitochondrial disruption. 2. ""BH3-only"" proteins such as BID,BAD, NOXA, PUMA,BIM, and BMF have only the short BH3 motif. These act upstream in the pathway, detecting developmental death cues or intracellular damage. Anti-apoptotic members like Bcl-2, Bcl-XL and their relatives exhibit homology in all segments BH1-4. One of the critical functions of BCL-2/BCL-XL proteins is to maintain the integrity of the mitochondrial outer membrane."
BMGC_PW0066,BMG_PW0105,"The apoptotic pathway involving the death receptors-mediated route of caspase activation. Members of the tumor necrosis superfamily such as the better known Tnf-alpha (Tnf), Fas ligand or Trail elicit apoptosis via receptor-associated adapters. [GO:0097191, KEGG:map04210, PMID:14744432, Reactome:R-HSA-5357769]","Apoptosis is a genetically programmed process for the elimination of damaged or redundant cells by activation of caspases (aspartate-specific cysteine proteases). The onset of apoptosis is controlled by numerous interrelating processes. The 'extrinsic' pathway involves stimulation of members of the tumor necrosis factor (TNF) receptor subfamily, such as TNFRI, CD95/Fas or TRAILR (death receptors), located at the cell surface, by their specific ligands, such as TNF-alpha, FasL or TRAIL, respectively. The 'intrinsic' pathway is activated mainly by non-receptor stimuli, such as DNA damage, ER stress, metabolic stress, UV radiation or growth-factor deprivation. The central event in the 'intrinsic' pathway is the mitochondrial outer membrane permeabilization (MOMP), which leads to the release of cytochrome c. These two pathways converge at the level of effector caspases, such as caspase-3 and caspase-7. The third major pathway is initiated by the constituents of cytotoxic granules (e.g. Perforin and Granzyme B) that are released by CTLs (cytotoxic T-cells) and NK (natural killer) cells. Granzyme B, similarly to the caspases, cleaves its substrates after aspartic acid residues, suggesting that this protease has the ability to activate members of the caspase family directly. It is the balance between the pro-apoptotic and anti-apoptotic signals that eventually determines whether cells will undergo apoptosis, survive or proliferate. TNF family of ligands activates anti-apoptotic or cell-survival signals as well as apoptotic signals. NGF and Interleukin-3 promotes the survival, proliferation and differentiation of neurons or hematopoietic cells, respectively. Withdrawal of these growth factors leads to cell death, as described above.","Caspases, a family of cysteine proteases, execute apoptotic cell death. Caspases exist as inactive zymogens in cells and undergo a cascade of catalytic activation at the onset of apoptosis. Initiation of apoptosis occurs through either a cell-intrinsic or cell-extrinsic pathway. Extrinsic pathway cell death signals originate at the plasma membrane where: An extracellular ligand (e.g., FasL) binds to its cell surface transmembrane “death receptor” (e.g., Fas receptor), inducing oligomerization of the receptor (Trauth et al. 1989; Itoh and Nagata 1993; Danial and Korsmeyer 2004). The ""death receptors"" are specialized cell-surface receptors including Fas/CD95, tumor necrosis factor-alpha (TNF-alpha) receptor 1, and two receptors, DR4 and DR5, that bind to the TNF-alpha related apoptosis-inducing ligand (TRAIL). Ligand binding promotes clustering of proteins that bind to the intracellular domain of the receptor (e.g., FADD, or Fas-associated death domain-containing protein), which then binds to the prodomain of initiator caspases (e.g.caspase-8 or -10) to promote their dimerization and activation. Active caspase-8/-10 can then directly cleave and activate effector caspases, such as caspase-3 or it can cleave Bid, which facilitates mitochondrial cytochrome c release. Unique group of proteins termed dependence receptors (DpRs) transduce positive (often prosurvival or progrowth) signals when engaged by ligand, but emit proapoptotic signals in the absence of ligand (Goldschneider and Mehlen 2010). DpR family includes p75 neurotrophin receptor (p75NTR), deleted in colon cancer (DCC), and UNC5 homologs, among others. cell-surface membrane receptors."
BMGC_PW0067,BMG_PW0106,"Those reactions involved in the breaking down of toxic chemical compounds such as oil spills, solvents, pesticides and other pollutants. These chemicals are generally resistant to degradation, but microorganisms possess enzymes that are capable of breaking them down. [GO:0042178, http://www.genome.jp/kegg/pathway.html#xenobiotics KEGG, Reactome:R-HSA-211981]",,"Of the 50 microsomal CYPs, 15 act on xenobiotics. They all possess wide substrate specificity to cater for most foreign compounds that find their way into the body."
BMGC_PW0068,BMG_PW0107,"Those enzymatic reactions involved in the degradation of caprolactam - a cyclic amide of caproic acid used to produce a type of nylon. [GO:0019384, KEGG:map00930, OneLook:www.onelook.com]",,
BMGC_PW0069,BMG_PW0108,"Those enzymatic reactions involved in the degradation of bisphenol A, known as BPA, an important compound in the production of plastics. However, it is believed to be hazardous to humans and reports have linked several health effects to levels of BPA exposure. [GO:0043636, KEGG:map00363, OneLook:www.onelook.com]",,
BMGC_PW0070,BMG_PW0109,"Those enzymatic reactions involved in the degradation of toluene and xylene. Toluene is used as organic solvent in rubber, paint, cement. Xylene represents any of three benzene derivatives used as solvent in printing, rubber, also as a cleaning agent. [KEGG:map00622, Onelook:www.onelook.com]",,
BMGC_PW0071,BMG_PW0110,"Those enzymatic reactions involved in the degradation of gamma-hexachlorocyclohexane,  also known as lindane, used as an insecticide and suspected to be carcinogenic. [KEGG:map00361, OneLook:www.onelook.com]",,
BMGC_PW0072,BMG_PW0112,"Those enzymatic reactions involved in the degradation of atrazine - a herbicide used to kill weeds. [GO:0019381, KEGG:map00791, OneLook:www.onelook.com]",,
BMGC_PW0073,BMG_PW0113,"Those enzymatic reactions involved in the aerobic pathway of benzoate degradation. [GO:0043640, KEGG:map00362, Online:Appl._Env._Microbiology\,_2004\,_v.70(9)\,_p4861-70.]",,
BMGC_PW0074,BMG_PW0117,"Those enzymatic reactions involved in the degradation of ethylbenzene - a liquid hydrocarbon used in the manufacture of styrene and as a solvent and diluent for dyes and paints. [KEGG:map00642, OneLook:www.onelook.com]",,
BMGC_PW0075,BMG_PW0119,"Those enzymatic reactions involved in the degradation of styrene - an aromatic hydrocarbon that is colorless and oily. It is used in the manufacture of rubber, resins and plastics. It is a toxic, possibly carcinogenic substance. [GO:0042207, KEGG:map00643, OneLook:www.onelook.com]",,
BMGC_PW0076,BMG_PW0120,"Those enzymatic reactions involved in the degradation of tetrachloroethene (acetylene tetrachloride) - used as a solvent for fats, waxes, resins and as an intermediate in the synthesis of chlorinated hydrocarbons. [GO:0019337, KEGG:map00625, OneLook:www.onelook.com]",,
BMGC_PW0077,BMG_PW0121,"The Hedgehog signaling pathway (Hh) plays important roles in vertebrate embryogenesis, particularly in the differentiation of the neural tube, in vasculogenesis and in angiogenesis. Post-embryonically it is believed to play a homeostatic role in the maintenance of stem cells. Alteration of the pathway has been implicated in a number of human cancers. [GO:0007224, KEGG:map04340, PID:200168, PID:200172, PMID:12495844, PMID:15205520, PMID:15596107, Reactome:R-HSA-5358351]","The Hedgehog (Hh) signaling pathway has numerous roles in the control of cell proliferation, tissue patterning, stem cell maintenance and development. The primary cilium is an important center for transduction of the Hedgehog signal in vertebrates. In Hh's absence, the Ptch receptor localizes to the cilium, where it inhibits Smo activation. Gli proteins are phosphorylated by PKA, CKI and GSK3B and partially degraded into truncated Gli repressor form (GliR) that suppresses Hh target gene transcription in the nucleus. In Hh's presence, Ptch disappears from the cilium, and activated Smo contributes to the translocation of the protein complex Gli, Sufu, Kif7 to ciliary tip, where Gli dissociates from the negative regulator Sufu. The production of Gli activator form (GliA) occurs and the increased nuclear accumulation of GliA results in activation transcription of Hh target genes.","Hedgehog (Hh) is a secreted morphogen that regulates developmental processes in vertebrates including limb bud formation, neural tube patterning, cell growth and differentiation (reviewed in Hui and Angers, 2011). Hh signaling also contributes to stem cell homeostasis in adult tissues. Downregulation of Hh signaling can lead to neonatal abnormalities, while upregulation of signaling is associated with the development of various cancers (Beachy et al, 2004; Jiang and Hui, 2008; Hui and Angers, 2011). Hh signaling is switched between 'off' and an 'on' states to differentially regulate an intracellular signaling cascade that targets the Gli transcription factors. In the absence of Hh ligand, cytosolic Gli proteins are cleaved to yield a truncated form that translocates into the nucleus and represses target gene transcription. Binding of Hh to the Patched (PTC) receptor on the cell surface stabilizes the Gli proteins in their full-length transcriptional activator form, stimulating Hh-dependent gene expression (reviewed in Hui and Angers, 2011; Briscoe and Therond, 2013)."
BMGC_PW0078,BMG_PW0124,"G-proteins act as signal transducers between activated receptors or other incoming signals and downstream effectors. They comprise the heterotrimeric G proteins downstream of G protein-coupled receptors (GPCRs) and the Ras superfamily of small, monomeric G proteins. They function as molecular switches, alternating between the GDP-inactive and GTP-active bound state. [GO:0007186, PMID:11152757, PMID:12040175, Reactome:R-HSA-372790]",,"G protein-coupled receptors (GPCRs; 7TM receptors; seven transmembrane domain receptors; heptahelical receptors; G protein-linked receptors [GPLR]) are the largest family of transmembrane receptors in humans, accounting for more than 1% of the protein-coding capacity of the human genome. All known GPCRs share a common architecture of seven membrane-spanning helices connected by intra- and extracellular loops. The extracellular loops contain two highly-conserved cysteine residues that form disulphide bonds to stabilize the structure of the receptor. They recognize diverse messengers such as light, odorants, small molecules, hormones and neurotransmitters. Most GPCRs act as guanine nucleotide exchange factors; activated by ligand binding, they promote GDP-GTP exchange on associated heterotrimeric guanine nucleotide-binding (G) proteins. There are two models for GPCR-G Protein interactions: 1) ligand-GPCR binding first, then binding to G Proteins; 2) ""Pre-coupling"" of GPCRs and G Proteins before ligand binding (review Oldham WM and Hamm HE, 2008). These in turn activate effector enzymes or ion channels. GPCRs are involved in a range of physiological roles which include the visual sense, smell, behavioural regulation, functions of the autonomic nervous system and regulation of the immune system and inflammation. GPCRs are divided into classes based on sequence homology and functional similarity. The main mammalian classes, in order of size, are the Rhodopsin-like family A, the Secretin receptor family B, and the Metabotropic glutamate/pheromone receptor family C."
BMGC_PW0079,BMG_PW0125,"The series of events governing the synthesis of the large ribosomal RNA (rRNA) precursor in the nucleolus. [GO:0006360, PMID:22365827, Reactome:R-HSA-73864]",,"RNA polymerase (Pol) I (one of three eukaryotic nuclear RNA polymerases) is devoted to the transcription of the ribosomal DNA genes, which are found in multiple arrayed copies in every eukaryotic cell. These genes encode for the large ribosomal RNA precursor, which is then processed into the three largest subunits of the ribosomal RNA, the 18S, 28S, and 5.8S RNAs. In human cells the rDNA gene clusters are localized on the short arm of the five pairs of the acrocentric chromosomes. The rRNA promoter has two essential and specially spaced sequences: a CORE element and an upstream control element (UCE, also called UPE). The CORE element of the human promoter overlaps with the transcription start site, extending from 20 to 45, and is required for specific initiation of transcription. The polymerase is a multisubunit complex, composed of two large subunits (the most conserved portions include the catalytic site that shares similarity with other eukaryotic and bacterial multisubunit RNA polymerases) and a number of smaller subunits. Under a number of experimental conditions the core is competent to mediate ribonucleic acid synthesis, in vivo however, it requires additional factors to select the appropriate template. In humans the RNA transcript (45S) is approximately 13,000 nucleotides long. Before leaving the nucleus as assembled ribosomal particles, the 45S rRNA is cleaved to give one copy each of the 28S rRNA, the 18S rRNA, and the 5.8S rRNA. Equal quantities of the three rRNAs are produced by initially transcribing them as one transcript."
BMGC_PW0080,BMG_PW0126,"The series of events governing the synthesis of protein-coding messenger RNA (mRNA) precursors and of transcripts of many classes of non-coding genes. [GO:0006366, http://en.wikipedia.org/wiki/Transcription_%28genetics%29 Wikipedia, PMID:22365827, PMID:23827673, Reactome:R-HSA-73857]",,"RNA polymerase II (Pol II) is the central enzyme that catalyses DNA- directed mRNA synthesis during the transcription of protein-coding genes. Pol II consists of a 10-subunit catalytic core, which alone is capable of elongating the RNA transcript, and a complex of two subunits, Rpb4/7, that is required for transcription initiation. The transcription cycle is divided in three major phases: initiation, elongation, and termination. Transcription initiation include promoter DNA binding, DNA melting, and initial synthesis of short RNA transcripts. The transition from initiation to elongation, is referred to as promoter escape and leads to a stable elongation complex that is characterized by an open DNA region or transcription bubble. The bubble contains the DNA-RNA hybrid, a heteroduplex of eight to nine base pairs. The growing 3-end of the RNA is engaged with the polymerase complex active site. Ultimately transcription terminates and Pol II dissocitates from the template."
BMGC_PW0081,BMG_PW0127,"The series of events governing the synthesis of transport/transfer RNA (tRNA) precursors, the small ribosomal rRNA and other small RNAs. [GO:0006383, PMID:22365827, Reactome:R-HSA-74158]",,"RNA polymerase III is one of three types of nuclear RNA polymerases present in eucaryotic cells. About 10% of the total transcription in dividing cells can be attributed to its activity. It synthesizes an eclectic collection of catalytic or structural RNA molecules, some of which are involved in protein synthesis, pre-mRNA splicing, tRNA processing, and the control of RNA polymerase II elongation, whereas some others have still unknown functions. Like other RNA polymerases, RNA polymerase III cannot recognize its target promoters directly. Instead it is recruited to specific promoter sequences through the help of transcription factors. There are three basic types of RNA polymerase III promoters, called types 1, 2, and 3(Geiduschek and Kassavetis, 1992). Although in vivo, RNA polymerase III may be recruited to these promoters as part of a large complex (holo RNA polymerase III) containing the polymerase and its initiation factors (Wang et al., 1997), in vitro the reaction can be divided into several steps. First, the promoter elements are recognized by DNA binding factors, which then recruit a factor known as TFIIIB. TFIIIB itself then directly contacts RNA polymerase III. In human cells but not in S. cerevisiae, there are at least two versions of TFIIIB. One contains TBP, Bdp1, and Brf1 (Brf1-TFIIIB), and the other TBP, Bdp1, and Brf2 (Brf2-TFIIIB) (Schramm et al., 2000; Teichmann et al., 2000)."
BMGC_PW0082,BMG_PW0128,"The base excision repair pathway involves the identification and removal of a damaged base followed by its replacement with the correct nucleotide and ligation of the break in the strand. [GO:0006284, KEGG:map03410, OneLook:www.onelook.com, Reactome:R-HSA-73884]","Base excision repair (BER) is the predominant DNA damage repair pathway for the processing of small base lesions, derived from oxidation and alkylation damages. BER is normally defined as DNA repair initiated by lesion-specific DNA glycosylases and completed by either of the two sub-pathways: short-patch BER where only one nucleotide is replaced and long-patch BER where 2-13 nucleotides are replaced. Each sub-pathway of BER relies on the formation of protein complexes that assemble at the site of the DNA lesion and facilitate repair in a coordinated fashion. This process of complex formation appears to provide an increase in specificity and efficiency to the BER pathway, thereby facilitating the maintenance of genome integrity by preventing the accumulation of highly toxic repair intermediates.","Of the three major pathways involved in the repair of nucleotide damage in DNA, base excision repair (BER) involves the greatest number of individual enzymatic activities. This is the consequence of the numerous individual glycosylases, each of which recognizes and removes a specific modified base(s) from DNA. BER is responsible for the repair of the most prevalent types of DNA lesions, oxidatively damaged DNA bases, which arise as a consequence of reactive oxygen species generated by normal mitochondrial metabolism or by oxidative free radicals resulting from ionizing radiation, lipid peroxidation or activated phagocytic cells. BER is a two-step process initiated by one of the DNA glycosylases that recognizes a specific modified base(s) and removes that base through the catalytic cleavage of the glycosydic bond, leaving an abasic site without disruption of the phosphate-sugar DNA backbone. Subsequently, abasic sites are resolved by a series of enzymes that cleave the backbone, insert the replacement residue(s), and ligate the DNA strand. BER may occur by either a single-nucleotide replacement pathway or a multiple-nucleotide patch replacement pathway, depending on the structure of the terminal sugar phosphate residue. The glycosylases found in human cells recognize ""foreign adducts"" and not standard functional modifications such as DNA methylation (Lindahl and Wood 1999, Sokhansanj et al. 2002)."
BMGC_PW0083,BMG_PW0129,"The nucleotide excision repair pathway is an important mechanism for the detection of helix-distorting base alterations. Unlike the base excision repair pathway that only removes the damaged bases, the NER pathway removes an entire lesion-containing segment. The single-strand gap thus introduced is filled in by DNA polymerase using the undamaged strand as a template. The pathway can be subdivided into two sub-pathways: transcription-coupled and global genome repair. They only differ in the lesion recognition step while the core repair component is shared. [GO:0006289, KEGG:map03420, OneLook:www.onelook.com, PMID:23046879, PMID:23085398, Reactome:R-HSA-5696398, SMP:00478]","Nucleotide excision repair (NER) is a mechanism to recognize and repair bulky DNA damage caused by compounds, environmental carcinogens, and exposure to UV-light. In humans hereditary defects in the NER pathway are linked to at least three diseases: xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD). The repair of damaged DNA involves at least 30 polypeptides within two different sub-pathways of NER known as transcription-coupled repair (TCR-NER) and global genome repair (GGR-NER). TCR refers to the expedited repair of lesions located in the actively transcribed strand of genes by RNA polymerase II (RNAP II). In GGR-NER the first step of damage recognition involves XPC-hHR23B complex together with XPE complex (in prokaryotes, uvrAB complex). The following steps of GGR-NER and TCR-NER are similar.","Nucleotide excision repair (NER) was first described in the model organism E. coli in the early 1960s as a process whereby bulky base damage is enzymatically removed from DNA, facilitating the recovery of DNA synthesis and cell survival. Deficient NER processes have been identified from the cells of cancer-prone patients with different variants of xeroderma pigmentosum (XP), trichothiodystrophy (TTD), and Cockayne's syndrome. The XP cells exhibit an ultraviolet radiation hypersensitivity that leads to a hypermutability response to UV, offering a direct connection between deficient NER, increased mutation rate, and cancer. While the NER pathway in prokaryotes is unique, the pathway utilized in yeast and higher eukaryotes is highly conserved. NER is involved in the repair of bulky adducts in DNA, such as UV-induced photo lesions (both 6-4 photoproducts (6-4 PPDs) and cyclobutane pyrimidine dimers (CPDs)), as well as chemical adducts formed from exposure to aflatoxin, benzopyrene and other genotoxic agents. Specific proteins have been identified that participate in base damage recognition, cleavage of the damaged strand on both sides of the lesion, and excision of the oligonucleotide bearing the lesion. Reparative DNA synthesis and ligation restore the strand to its original state. NER consists of two related pathways called global genome nucleotide excision repair (GG-NER) and transcription-coupled nucleotide excision repair (TC-NER). The pathways differ in the way in which DNA damage is initially recognized, but the majority of the participating molecules are shared between these two branches of NER. GG-NER is transcription-independent, removing lesions from non-coding DNA strands, as well as coding DNA strands that are not being actively transcribed. TC-NER repairs damage in transcribed strands of active genes. Several of the proteins involved in NER are key components of the basal transcription complex TFIIH. An ubiquitin ligase complex composed of DDB1, CUL4A or CUL4B and RBX1 participates in both GG-NER and TC-NER, implying an important role of ubiquitination in NER regulation. The establishment of mutant mouse models for NER genes and other DNA repair-related genes has been useful in demonstrating the associations between NER defects and cancer. For past and recent reviews of nucleotide excision repair, please refer to Lindahl and Wood 1998, Friedberg et al. 2002, Christmann et al. 2003, Hanawalt and Spivak 2008, Marteijn et al. 2014)."
BMGC_PW0084,BMG_PW0131,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of selenoamino acids - amino acids in which a selenium atom replaces a sulfur atom. Examples include selenocysteine, selenohomocysteine and selenomethionine. [http://morelife.org/glossary/ Technical glossary, http://pathman.smpdb.ca/pathways/SMP00029/pathway SMPDB, KEGG:map00450, Reactome:R-HSA-2408522, SMP:00029]",,"Selenium (Se) is a trace element essential for the normal function of the body. Selenoamino acids are defined as those amino acids where selenium has been substituted for sulphur. Selenium and sulphur share many chemical properties and so the substitution of normal amino acids with selenoamino acids has little effect on protein structure and function. Both inorganic (selenite, SeO3(2-); and selenate, SeO4(2-)) and organic (selenocysteine, Sec; and selenomethionine, SeMet) forms of selenium can be introduced in the diet where they are transformed into the intermediate selenide (Se(2-)) and then utilized for the de novo synthesis of Sec through a phosphorylated intermediate in a tRNA-dependent fashion. The final step of Sec formation is catalyzed by O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase (SEPSECS) that converts phosphoseryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec). All nutritional selenium is metabolised into selenide directly or through methylselenol (MeSeH). Sec liberated from selenoproteins is transformed to Se(2-) by selenocysteine lyase (SCLY). SeMet liberated from general proteins and from free SeMet sources is transformed into Se(2-) either through MeSeH by cystathionine gamma-lyase (CTH) followed by demethylation (SeMet to CH3SeH to H2Se), or through Sec by SCLY after the trans-selenation pathway (SeMet to Sec to H2Se). MeSec is hydrolysed into MeSeH by CTH. Methylseleninic acid (MeSeO2H) is reduced to methylselenol. MeSeH is demethylated to Se(2-) for further utilization for selenoprotein synthesis or oxidised to selenite (SeO3(2-)) for excretion in the form of selenosugar. Additionally, MeSeH is further methylated to dimethylselenide (Me2Se) and trimethylselenonium (Me3Se+) for excretion."
BMGC_PW0085,BMG_PW0132,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glutathione - a tripeptide that acts as an antioxidant and provides protection against reactive oxygen species. It is also used in the conjugation of xenobiotics and drugs by the phase II biotransformation enzymes. [GO:0006749, https://en.wikipedia.org/wiki/Glutathione wikipedia, KEGG:00480, SMP:00015]",,"The combination of glutamate, cysteine and ATP is required to form glutathione. The steps involved in the synthesis and recycling of glutathione are outlined (Meister, 1988)."
BMGC_PW0086,BMG_PW0133,"Those reactions involved in the synthesis, utilization and/or degradation of cofactors, vitamins and other nutrients. Cofactors are necessary for the proper function of certain proteins and enzymes; they can be inorganic such as the metal ions or the iron-sulfur cluster or organic. Organic compounds that are tightly bound to proteins are also referred to as prosthetic groups. Often, they are or are made from vitamins, compounds that are vital but in small amounts and which are insufficiently synthesized by the organism. Some of these molecules can also perform signaling functions. [http://www.onelook.com OneLook, Reactome:R-HSA-196854]",,"Vitamins are a diverse group of organic compounds, classified according to their solubility, either fat-soluble or water-soluble, that are either not synthesized or synthesized only in limited amounts by human cells. They are required in small amounts in the diet and have distinct biochemical roles, often as coenzymes (cofactors). The physiological processes dependent on vitamin-requiring reactions include many aspects of intermediary metabolism, vision, bone formation, and blood coagulation, and vitamin deficiencies are associated with a correspondingly diverse and severe group of diseases. Metabolic pathways for water-soluble B group and C vitamins, and for fat-soluble vitamins A, D and K are annotated in Reactome, covering processes that convert dietary forms of these molecules into active forms, and that regenerate active forms of vitamin cofactors consumed in other metabolic processes."
BMGC_PW0087,BMG_PW0135,"Those metabolic reactions involving riboflavin, also known as vitamin B2 - a water-soluble vitamin. B2 occurs in several products and is a precursor for flavin coenzymes. [GO:0006771, https://en.wikipedia.org/wiki/Riboflavin wikipedia, KEGG:00740, Reactome:R-HSA-196843, SMP:00070]",,"Riboflavin (vitamin B2, E101) is an essential component for the cofactors FAD (flavin-adenine dinucleotide) and FMN (flavin mononucleotide). Together with NAD+ and NADP+, FAD and FMN are important hydrogen carriers and take part in more than 100 redox reactions involved in energy metabolism. Riboflavin is present in many vegetables and meat and during digestion, various flavoproteins from food are degraded and riboflavin is resorbed. The major degradation and excretion product in humans is riboflavin (Rivlin 1970)."
BMGC_PW0088,BMG_PW0136,"Those metabolic reactions involving vitamin B6 - a water-soluble vitamin that exists in several forms. Vitamin B6 is required for many enzymatic reactions as the active pyridoxal 5'-phosphate (PLP) form. A number of organisms can carry out de novo synthesis of vitamin B6; humans derive it from diet. [GO:0042816, https://en.wikipedia.org/wiki/Vitamin_B6 wikipedia, KEGG:00750, SMP:00017]",,
BMGC_PW0089,BMG_PW0137,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of biotin, also known as vitamin B7 or H, a water-soluble vitamin. Biotin assists in various metabolic reactions and processes. [GO:0006768, https://en.wikipedia.org/wiki/Biotin wikipedia, KEGG:00780, Reactome:R-HSA-196780, SMP:00066]","Biotin (vitamin H or vitamin B7) is the essential cofactor of biotin-dependent carboxylases, such as pyruvate carboxylase and acetyl-CoA carboxylase. Mammals cannot synthesize biotin, while in bacteria, fungi, and plants it is synthesized from pimelate thioester through different pathways. In E. coli and many organisms, pimelate thioester is derived from malonyl-ACP. The pathway starts with the methylation to malonyl-ACP methyl ester, followed by the fatty acid chain elongation cycle to form pimeloyl-ACP methyl ester, which is then demethylated to form pimeloyl-ACP [MD:M00572]. Pimeloyl-ACP is converted to biotin through the final four steps in the biotin bicyclic ring assembly, which are conserved among biotin-producing organisms [MD:M00123]. In B. subtilis, biotin is derived from pimeloyl-ACP formed by oxidative cleavage of long-chain acyl-ACPs [MD:M00573]. Some bacteria synthesize biotin from pimeloyl-CoA derived from pimelate [MD:M00577]. Biotin is covalently attached to biotin-dependent carboxylase by biotin protein ligase, also known as holocarboxylase synthase in mammals, to form an active holocarboxylase. After degradation of the biotinylated carboxylase into biocytin, it is further degraded by biotinidase to release free biotin, which is recycled in holocarboxylase synthesis. Biotin is catabolized by beta-oxidation of the valeric acid side chain or oxidation of sulfur in the heterocyclic ring.","Biotin (Btn) is an essential cofactor in a variety of carboxylation reactions (Zempleni et al. 2009). Humans cannot synthesize Btn but it is abundant in the human diet and can be taken up from the intestinal lumen by the SLC5A6 transporter. Its uptake, intracellular translocation, covalent conjugation to apoenzymes, and salvage are described here."
BMGC_PW0090,BMG_PW0138,"Folate metabolism represents the various aspects of the folate cycle and the folate-mediated transfer reactions essential for several biosynthetic pathways. The folate cycle and the folate-mediated one-carbon pathways are part of folate metabolism. Folate compounds are water-soluble forms of vitamin B9. [GO:0046655, KEGG:00790, PMID:11001804, PMID:15166809, PMID:15298442, SMP:00053]",,
BMGC_PW0091,BMG_PW0139,"Those reactions involving retinol, a fat-soluble vitamin that is the dietary form of vitamin A and is important for bone growth and in vision. Precursors of retinol such as carotenoid or retinyl esters are derived from diet and are converted to retinal and retinol, respectively. [GO:0042572, KEGG:map00830, OneLook:www.onelook.com, PMID:21586336, PMID:21718801, Reactome:R-HSA-975634, SMP:00074]",,"Vitamin A (all-trans-retinol) must be taken up, either as carotenes from plants, or as retinyl esters from animal food. The most prominent carotenes are alpha-carotene, lycopene, lutein, beta-cryptoxanthine, and especially beta-carotene. After uptake they are mostly broken down to retinal. Retinyl esters are hydrolysed like other fats. In enterocytes, retinoids bind to retinol-binding protein (RBP). Transport from enterocytes to the liver happens via chylomicrons (Harrison & Hussain 2001, Harrison 2005)."
BMGC_PW0092,BMG_PW0140,"Those metabolic reactions involved in the biosynthesis of ubiquinone, also known as coenzyme Q. Ubiquinone is a member of the mitochondrial respiratory chain and plays important roles in cellular metabolism. [GO:0006744, KEGG:00130, PMID:14757233, Reactome:R-HSA-2142789, SMP:00065]","Ubiquinone (UQ), also called coenzyme Q, and plastoquinone (PQ) are electron carriers in oxidative phosphorylation and photosynthesis, respectively. The quinoid nucleus of ubiquinone is derived from the shikimate pathway; 4-hydroxybenzoate is directly formed from chorismate in bacteria, while it can be formed from either chorismate or tyrosine in yeast. The following biosynthesis of terpenoid moiety involves reactions of prenylation, decarboxylation, and three hydroxylations alternating with three methylations. The order of these reactions are somewhat different between bacteria and yeast. Phylloquinone (vitamin K1), menaquinone (vitamin K2), and tocopherol (vitamin E) are fat-soluble vitamins. Phylloquinone is a compound present in all photosynthetic plants serving as a cofactor for photosystem I-mediated electron transport. Menaquinone is an obligatory component of the electron-transfer pathway in bacteria.","The length of the polyisoprenoid chain of ubiquinone, aka coenzyme Q (CoQ), varies depending on the species involved: it is 6 in budding yeast, Saccharomyces cerevisiae, (CoQ6) and 10 in humans (CoQ10). Most ubiquinone is naturally reduced to ubiquinol (CoQ10H2 in humans), and this form dominates in human tissues. It functions as a ubiquitous coenzyme in redox reactions, and has a central role in the electron transport chain of the inner mitochondrial membrane.to shuttle electrons from complexes I and II to complex III. It also acts as a cofactor for biosynthetic and catabolic reactions, detoxifies damaging lipid species, and engages in cellular signaling and oxygen sensing. In eukaryotes, ubiquinones/ubiquinols are also found in other membranes such as the endoplasmic reticulum, Golgi vesicles, lysosomes, peroxisomes and the plasma membrane (reviewed in Guerra & Pagliarini, 2023). Ubiquinol/ubiquinone is synthesized in the following way. Initially, mitochondrial 4-hydroxyphenylpyruvate dioxygenase-like protein (HPDL) processes 4-hydroxphenylpyruvate (HPP, HPPA) to (S)-4-hydroxymandelate (4-HMA). HPDL defects lead to CoQ10 deficiency. The HPDL product 4-HMA is a precursor for the synthesis of 4-hydroxybenzoate (PHB), from which the CoQ10 head group is derived (Banh et al., 2021). Because HPDL is a mitochondrial protein, cytosolic HPP from tyrosine catabolism must either be imported by a yet unknown transport mechanism or mitochondrial HPP could be the product of an unknown mitochondrial reaction (Husain et al., 2020; reviewed in Staiano et al., 2023). A polyprenyl diphosphate synthase (PDSS1-2) assembles the polyisoprenoid tail. Next, 4-hydroxybenzoate polyprenyltransferase (COQ2) catalyzes the formation of the covalent linkage between PHB and the polyisoprenoid tail to produce 4-hydroxy-3-polyprenyl benzoic acid intermediate (DHB, 3-decaprenyl-4-hydroxybenzoic acid in humans). Modifications of the aromatic ring follow and involve an oxidative decarboxylation, two hydroxylations, two O-methylations, one C-methylation. This series of reactions, which precise order is not fully established, especially regarding the oxidative decarboxylation step (Pelosi et al., 2024; Nicoll et al., 2024), yield the fully substituted hydroquinone, ubiquinol (reviewed in Guerra & Pagliarini, 2023). Homologs of the core enzymes COQ3, COQ4, COQ5, COQ6, COQ7, and COQ9 have been shown to form a membrane-localized multienzyme complex (""COQ synthome"") in yeast (He et al., 2014). There is some evidence of such a complex, called complex Q, in humans (Floyd et al., 2016). A complex was reconstituted in vitro with ancestral versions of COQ3-7 and COQ9, and was able to convert a short chain analog of DHB (4-Hydroxy-3-(3-methylbut-2-en-1-yl)benzoic acid) into CoQ1 (Nicoll et al., 2024). COQ8A and COQ8B proteins may contribute to the formation and functionality of this complex, as they can bind to most core enzymes (Floyd et al., 2016), and as COQ8B increased the in vitro activity of COQ6 via phosphorylation of COQ3 (Nicoll et al., 2024).. Parts of CoQ10 synthesis may also occur in the Golgi and endoplasmic reticulum membranes, adding to the cellular membrane CoQ10 pool. The relevance of such processes seems minor (Kalén et al., 1990; Staiano et al., 2023).The precise function of two other genes, COQ10A and COQ10B, which appear to be quinone-binding proteins, is still under investigation. Most of the time, CoQ10 is transported out of the mitochondrion and to the plasma membrane by isoforms of the STARD7 lipid carrier (reviewed in Guile et al., 2023). CoQ10 deficiency, which can result from reduced activity of any biosynthesis core enzymes or the COQ8A, and COQ8B proteins, has significant implications. It is associated with several inherited metabolic disorders, the phenotypes of which are extremely heterogeneous. These disorders range from fatal neonatal presentations with multisystem involvement to adult-onset isolated myopathy. However, in many cases, the symptoms can be ameliorated by nutritional supplementation with CoQ10 (reviewed in Quinzii et al., 2017; Staiano et al., 2023)."
BMGC_PW0093,BMG_PW0141,"Insulin, the peptide hormone secreted by pancreatic beta cells, plays essential roles in glucose and energy homeostasis. Insulin signaling activates two main intracellular pathways to regulate carbohydrate and fat metabolism and to prompt glucose absorption in insulin sensitive tissues such as skeletal muscle and adipocytes. Deregulation of the pathway has been associated with a number of conditions, primarily diabetes. [GO:0008286, KEGG:map4910, PID:200014, PMID:12169433, Reactome:R-HSA-74752, SMP:00391]",,"Insulin binding to its receptor results in receptor autophosphorylation on tyrosine residues and the tyrosine phosphorylation of insulin receptor substrates (e.g. IRS and Shc) by the insulin receptor tyrosine kinase. This allows association of IRSs with downstream effectors such as PI-3K via its Src homology 2 (SH2) domains leading to end point events such as Glut4 (Slc2a4) translocation. Shc when tyrosine phosphorylated associates with Grb2 and can thus activate the Ras/MAPK pathway independent of the IRSs. Signal transduction by the insulin receptor is not limited to its activation at the cell surface. The activated ligand-receptor complex initially at the cell surface, is internalised into endosomes itself a process which is dependent on tyrosine autophosphorylation. Endocytosis of activated receptors has the dual effect of concentrating receptors within endosomes and allows the insulin receptor tyrosine kinase to phosphorylate substrates that are spatially distinct from those accessible at the plasma membrane. Acidification of the endosomal lumen, due to the presence of proton pumps, results in dissociation of insulin from its receptor. (The endosome constitutes the major site of insulin degradation). This loss of the ligand-receptor complex attenuates any further insulin-driven receptor re-phosphorylation events and leads to receptor dephosphorylation by extra-lumenal endosomally-associated protein tyrosine phosphatases (PTPs). The identity of these PTPs is not clearly established yet."
BMGC_PW0094,BMG_PW0149,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of starch and sucrose, as depicted in the KEGG diagram. Starch is a polysaccharide produced by all green plants and is an important carbohydrate in the human diet. Sucrose, or the table sugar is a disaccharide of glucose and fructose that is produced by plants and cyanobacteria. [http://www.onelook.com OneLook, KEGG:map00500]",,
BMGC_PW0095,BMG_PW0150,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of amino sugars. An amino sugar has an amino group substituent in place of a hydroxyl group. Amino sugars are important constituents of a variety of polysaccharides and glycoproteins. [GO:0006040, https://en.wikipedia.org/wiki/Amino_sugar wikipedia, KEGG:00520, SMP:00045]",,
BMGC_PW0096,BMG_PW0151,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of triacylglycerols - esters of glycerols with three fatty acid molecules. Triglycerides are the common form of transport and storage of fatty acids. Esters with one or two fatty acid molecules are metabolic intermediates present in small amounts. [GO:0006641, KEGG:map00561, MCW_library:QU4_M235b_2009, OneLook:www.onelook.com, Reactome:R-HSA-8979227]",,"Fatty acids derived from the diet and synthesized de novo in the liver are assembled into triglycerides (triacylglycerols) for transport and storage. Synthesis proceeds in steps of conversion of fatty acyl-CoA to phosphatidic acid, conversion of phosphatidic acid to diacylglycerol, and conversion of diacylglycerol to triacylglycerol (Takeuchi & Reue 2009). Hydrolysis of triacylglycerol to yield fatty acids and glycerol is a tightly regulated part of energy metabolism. A central part in this regulation is played by hormone-sensitive lipase (HSL), a neutral lipase abundant in adipocytes and skeletal and cardiac muscle, but also abundant in ovarian and adrenal tissue, where it mediates cholesterol ester hydrolysis, yielding cholesterol for steroid biosynthesis. The hormones to which it is sensitive include catecholamines (e.g., epinephrine), ACTH, and glucagon, all of which trigger signaling cascades that lead to its phosphorylation and activation, and insulin, which sets off events leading to its dephosphorylation and inactivation (Kraemer & Shen 2002). The processes of triacylglycerol and cholesterol ester hydrolysis are also regulated by subcellular compartmentalization: these lipids are packaged in cytosolic particles and the enzymes responsible for their hydrolysis, and perhaps for additional steps in their metabolism, are organized at the surfaces of these particles (e.g., Brasaemle et al. 2004)."
BMGC_PW0097,BMG_PW0152,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of inositol phosphate, which represents all of the possible phosphorylated states of inositol. Inositol phosphates have many important cellular functions. [GO:0043647, KEGG:map00562, OneLook:www.onelook.com, Reactome:R-HSA-1483249, SMP:00462]",,"Inositol phosphates (IPs) are molecules involves in signalling processes in eukaryotes. myo-Inositol consists of a six-carbon cyclic alcohol with an axial 2-hydroxy and five equatorial hydroxyls. Mono-, di-, and triphosphorylation of the inositol ring generates a wide variety of stereochemically distinct signalling entities. Inositol 1,4,5-trisphosphate (I(1,4,5)P3), is formed when the phosphoinositide phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) is hydrolysed by a phospholipase C isozyme. An array of inositol trisphosphate (IP3) and tetrakisphosphate (IP4) molecules are synthesised by the action of various kinases and phosphatases in the cytosol. These species then transport between the cytosol and the nucleus where they are acted on by inositol polyphosphate multikinase (IPMK), inositol-pentakisphosphate 2-kinase (IPPK), inositol hexakisphosphate kinase 1 (IP6K1) and 2 (IP6K2), to produce IP5, IP6, IP7, and IP8 molecules. Some of these nuclear produced IPs transport back to the cytosol where they are converted to an even wider variety of IPs, by kinases and phosphatases, including the di- and triphospho inositol phosphates aka pyrophosphates (Irvine & Schell 2001, Bunney & Katan 2010, Alcazar-Romain & Wente 2008, York 2006, Monserrate and York 2010)."
BMGC_PW0098,BMG_PW0155,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glycosaminoglycans - any of several high molecular weight linear polysaccharides of repeating disaccharide units. In many cases, the unit consists of an amino sugar and a uronic acid. When aggregating with proteins, they form proteoglycans. [GO:0030203, http://en.wikipedia.org/wiki/Glycosaminoglycan wikipedia, MCW_Libraries:QU4_V876f_2008, Reactome:R-HSA-1630316]",,"Glycosaminoglycans (GAGs) are long, unbranched polysaccharides containing a repeating disaccharide unit composed of a hexosamine (either N-acetylgalactosamine (GalNAc) or N-acetylglucosamine (GlcNAc)) and a uronic acid (glucuronate or iduronate). They can be heavily sulfated. GAGs are located primarily in the extracellular matrix (ECM) and on cell membranes, acting as a lubricating fluid for joints and as part of signalling processes. They have structural roles in connective tissue, cartilage, bone and blood vessels (Esko et al. 2009). GAGs are degraded in the lysosome as part of their natural turnover. Defects in the lysosomal enzymes responsible for the metabolism of membrane-associated GAGs lead to lysosomal storage diseases called mucopolysaccharidoses (MPS). MPSs are characterised by the accumulation of GAGs in lysosomes resulting in chronic, progressively debilitating disorders that in many instances lead to severe psychomotor retardation and premature death (Cantz & Gehler 1976, Clarke 2008). The biosynthesis and breakdown of the main GAGs (hyaluronate, keratan sulfate, chondroitin sulfate, dermatan sulfate and heparan sulfate) is described here."
BMGC_PW0099,BMG_PW0159,"Those metabolic reactions involved in the synthesis of glycosylphosphatidylinositol (GPI) anchors. The GPI anchor allows for the attachment of cell surface proteins to the cell membrane. [GO:0006506, InHouse:InHouse_PW_dictionary, KEGG:map00563, Reactome:R-HSA-162710]","Cell surface proteins can be attached to the cell membrane via the glycolipid structure called glycosylphosphatidylinositol (GPI) anchor. Hundreds of GPI-anchored proteins have been identified in many eukaryotes ranging from protozoa and fungi to mammals. All protein-linked GPI anchors share a common core structure, characterized by the substructure Man (a1-4) GlcN (a1-6) myo-inositol-1P-lipid. Biosynthesis of GPI anchors proceeds in three stages: (i) preassembly of a GPI precursor in the ER membrane, (ii) attachment of the GPI to the C-terminus of a newly synthesized protein in the lumen of the ER, and (iii) lipid remodeling and/or carbohydrate side-chain modifications in the ER and the Golgi. Defects of GPI anchor biosynthesis gene result in a genetic disorder, paroxysmal nocturnal hemoglobinuria.","Glycosylphosphatidyl inositol (GPI) acts as a membrane anchor for many cell surface proteins. GPI is synthesized in the endoplasmic reticulum. In humans, a single pathway consisting of nine reactions appears to be responsible for the synthesis of the major GPI species involved in membrane protein anchoring. This pathway is shown in the figure. Two additional reactions, not shown, allow the synthesis of variant forms of GPI, one with an additional mannose residue and one with an additional ethanolamine (Tauron et al. 2004; Shishioh et al. 2005). These variant GPI molecules may be used for tissue-specific protein modifications, or may function independently. The steps of GPI synthesis were first identified by isolating large numbers of mutant cell lines that had lost the ability to express GPI anchored proteins on their surfaces. Somatic cell hybrid analyses of these lines allowed the definition of complementation groups corresponding to distinct mutated genes, and cDNAs corresponding to normal forms of these genes were identified on the basis of their abilities to restore normal cell surface protein expression in mutant cells. Co-precipitation experiments with tagged cloned proteins have allowed the identification of additional proteins involved in GPI anchor biosynthesis."
BMGC_PW0100,BMG_PW0160,"Those metabolic reactions involved in the synthesis of sphingolipids. Sphingolipids are enriched in the Central Nervous System (CNS) and display multiple biological functions. They participate in tissue development, cell recognition and adhesion, and act as receptors for toxins. [GO:0030148, Reactome:R-HSA-1660661]",,"Glycosphingolipid biosynthesis is based on salvage of sphingolipids and de novo sphingolipid synthesis. Sphingoid-1-phosphate signalling molecules are synthesized through the same pathway, which starts with the transfer of a fatty acid onto serine. The diversity of products results from later dehydrogenation or hydroxylation of fatty acid moieties, as well as the usage of fatty acids of different lengths. Biosynthesis takes place in the endoplasmic reticulum lumen and the cytosol. Lipophilic products are transported to other membranes via a specialized transporter (CERT1) or the secretory pathway. Soluble sphingoid-1-phosphates are exported by multiple transporters in the plasma membrane (reviewed by Merrill 2002, Gault et al. 2010)."
BMGC_PW0101,BMG_PW0162,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of gangliosides - any of a group of glycosphingolipids in which the polar head group on ceramide is a sialic acid. Their names include letters and numbers where the letters M, D and T indicate the number of sialic acid residues in the molecule - one, two or three, respectively. [GO:0001573, KEGG:00604, OneLook:www.onelook.com]",,
BMGC_PW0102,BMG_PW0163,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of taurine and hypotaurine. [InHouse:PW_InHouse_dictionary, KEGG:map00430]",,
BMGC_PW0103,BMG_PW0164,"Those metabolic reactions involved in the synthesis of monoterpenoids. Terpenoids are a large class of naturally-occurring organic chemicals. They are derived from five-carbon units and are modified in manifold ways. [GO:0016099, KEGG:00760]",,
BMGC_PW0104,BMG_PW0165,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of pantothenic acid or panthothenate, also known as vitamin B5 - a water-soluble vitamin. Vitamin B5 is the precursor to coenzyme A (CoA) which in turn, plays an essential role in fatty acids and pyruvate metabolism. [GO:0015939, https://en.wikipedia.org/wiki/Pantothenic_acid wikipedia, KEGG:00770, Reactome:R-HSA-199220, SMP:00027]",,"Vitamin B5 ((R)-pantothenate, PanK), is an essential precursor for the synthesis of the metabolic cofactor Coenzyme A (CoA-SH) (Robishaw and Neely 1985) and is the prosthetic group of acyl carrier protein (ACP) (Joshi et al. 2003). The name pantothenate is from the Greek “pantothen”, ""from everywhere"". Both pantothenate and CoA-SH are found in nearly every foodstuff and in the gut microbiome. CoA-SH itself is readily degraded in the gut and in extracellular fluids within the body. No processes are known to transport it across plasma membranes. Instead, individual cells take up PanK, which is stable in the extracellular environment, to synthesize CoA-SH for their own use. Within a cell, distinct groups of CoA-SH-requiring reactions occur in the cytosol, mitochondrial matrix, and peroxisomes, and controlling CoA pool size in each location plays a major role in regulating and integrating cellular metabolic processes. Control is achieved by selective degradation, synthesis, and transport of CoA within a cell (Cavestro et al. 2023, Naquet et al. 2020). The reactions annotated here provide an incomplete description of these processes, as key steps remain incompletely understood."
BMGC_PW0105,BMG_PW0168,"Members of the EGF/neuregulin superfamily are important regulators of tissue development and repair. A characteristic feature is the presence of the EGF module, a 36-40 amino acid sequence with a disulfide-bonded three-loop structure necessary for receptor binding. [GO:0007173, KEGG:map04012, MCW_e-journal:J._Mol._Evolo.2000\,_v50\,_p397-412, PID:200101, PID:200159, PMID:12814936, Reactome:R-HSA-177929]","The ErbB family of receptor tyrosine kinases (RTKs) couples binding of extracellular growth factor ligands to intracellular signaling pathways regulating diverse biologic responses, including proliferation, differentiation, cell motility, and survival. Ligand binding to the four closely related members of this RTK family -epidermal growth factor receptor (EGFR, also known as ErbB-1 or HER1), ErbB-2 (HER2), ErbB-3 (HER3), and ErbB-4 (HER4)-induces the formation of receptor homo- and heterodimers and the activation of the intrinsic kinase domain, resulting in phosphorylation on specific tyrosine residues (pY) within the cytoplasmic tail. Signaling effectors containing binding pockets for pY-containing peptides are recruited to activated receptors and induce the various signaling pathways. The Shc- and/or Grb2-activated mitogen-activated protein kinase (MAPK) pathway is a common target downstream of all ErbB receptors. Similarly, the phosphatidylinositol-3-kinase (PI-3K) pathway is directly or indirectly activated by most ErbBs. Several cytoplasmic docking proteins appear to be recruited by specific ErbB receptors and less exploited by others. These include the adaptors Crk, Nck, the phospholipase C gamma (PLCgamma), the intracellular tyrosine kinase Src, or the Cbl E3 ubiquitin protein ligase.","The epidermal growth factor receptor (EGFR) is one member of the ERBB family of transmembrane glycoprotein tyrosine receptor kinases (RTK). Binding of EGFR to its ligands induces conformational change that unmasks the dimerization interface in the extracellular domain of EGFR, leading to receptor homo- or heterodimerization at the cell surface. Dimerization of the extracellular regions of EGFR triggers additional conformational change of the cytoplasmic EGFR regions, enabling the kinase domains of two EGFR molecules to achieve the catalytically active conformation. Ligand activated EGFR dimers trans-autophosphorylate on tyrosine residues in the cytoplasmic tail of the receptor. Phosphorylated tyrosines serve as binding sites for the recruitment of signal transducers and activators of intracellular substrates, which then stimulate intracellular signal transduction cascades that are involved in regulating cellular proliferation, differentiation, and survival. Recruitment of complexes containing GRB2 and SOS1 to phosphorylated EGFR dimers either directly, through phosphotyrosine residues that serve as GRB2 docking sites, or indirectly, through SHC1 recruitment, promotes GDP to GTP exchange on RAS, resulting in the activation of RAF/MAP kinase cascade. Binding of complexes of GRB2 and GAB1 to phosphorylated EGFR dimers leads to formation of the active PI3K complex, conversion of PIP2 into PIP3, and activation of AKT signaling. Phospholipase C-gamma1 (PLCG1) can also be recruited directly, through EGFR phosphotyrosine residues that serve as PLCG1 docking sites, which leads to PLCG1 phosphorylation by EGFR and activation of DAG and IP3 signaling. EGFR signaling is downregulated by the action of ubiquitin ligase CBL. CBL binds directly to the phosphorylated EGFR dimer through the phosphotyrosine Y1069 (i.e. Y1045 in the mature protein) in the C-tail of EGFR, and after CBL is phosphorylated by EGFR, it becomes active and ubiquitinates phosphorylated EGFR dimers, targeting them for degradation. Positive regulation of EGFR signaling by direct association of EGFR with accessory proteins such as AAMP and FAM83B is being investigated. For review of EGFR signaling, please refer to Carpenter 1999, Wells 1999, Schlessinger 2002, Herbst 2004, Avraham and Yarden, 2011, Bartel et al. 2016, Uribe et al. 2021, Keflee et al. 2022."
BMGC_PW0106,BMG_PW0178,"The mTOR signaling pathway regulates cellular processes such as translation, ribosome biogenesis, cell growth and autophagy and is regulated by or responds to growth factors, energy metabolites and/or levels of nutrients. [GO:0031929, KEGG:map04150, PID:200096, PubMed:TIBS\,_2004\,_v._29(1)\,_32-38., Reactome:R-HSA-165159]","The mammalian (mechanistic) target of rapamycin (mTOR) is a highly conserved serine/threonine protein kinase, which exists in two complexes termed mTOR complex 1 (mTORC1) and 2 (mTORC2). mTORC1 contains mTOR, Raptor, PRAS40, Deptor, mLST8, Tel2 and Tti1. mTORC1 is activated by the presence of growth factors, amino acids, energy status, stress and oxygen levels to regulate several biological processes, including lipid metabolism, autophagy, protein synthesis and ribosome biogenesis. On the other hand, mTORC2, which consists of mTOR, mSin1, Rictor, Protor, Deptor, mLST8, Tel2 and Tti1, responds to growth factors and controls cytoskeletal organization, metabolism and survival.","Target of rapamycin (mTOR) is a highly-conserved serine/threonine kinase that regulates cell growth and division in response to energy levels, growth signals, and nutrients (Zoncu et al. 2011). Control of mTOR activity is critical for the cell since its dysregulation leads to cancer, metabolic disease, and diabetes (Laplante & Sabatini 2012). In cells, mTOR exists as two structurally distinct complexes termed mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), each one with specificity for different sets of effectors. mTORC1 couples energy and nutrient abundance to cell growth and proliferation by balancing anabolic (protein synthesis and nutrient storage) and catabolic (autophagy and utilization of energy stores) processes."
BMGC_PW0107,BMG_PW0182,"Those metabolic reactions involved in the synthesis of terpenoids. The terpenoids, sometimes referred to as isoprenoids, are a class of naturally-occurring chemicals. Terpenoids are derived from five-carbon isoprene units and are assembled and modified in manifold ways. They are classified according to the number of isoprene units. The mevalonate pathway and the non-mevalonate MEP/DOXP pathway are the two biosynthetic routes. The first can branch into non-sterol and sterol-producing compounds. The second is only found in plants. [GO:0016114, KEGG:map00900, OneLook:www.onelook.com]","Terpenoids, also known as isoprenoids, are a large class of natural products consisting of isoprene (C5) units. There are two biosynthetic pathways, the mevalonate pathway [MD:M00095] and the non-mevalonate pathway or the MEP/DOXP pathway [MD:M00096], for the terpenoid building blocks: isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). The action of prenyltransferases then generates higher-order building blocks: geranyl diphosphate (GPP), farsenyl diphosphate (FPP), and geranylgeranyl diphosphate (GGPP), which are the precursors of monoterpenoids (C10), sesquiterpenoids (C15), and diterpenoids (C20), respectively. Condensation of these building blocks gives rise to the precursors of sterols (C30) and carotenoids (C40). The MEP/DOXP pathway is absent in higher animals and fungi, but in green plants the MEP/DOXP and mevalonate pathways co-exist in separate cellular compartments. The MEP/DOXP pathway, operating in the plastids, is responsible for the formation of essential oil monoterpenes and linalyl acetate, some sesquiterpenes, diterpenes, and carotenoids and phytol. The mevalonate pathway, operating in the cytosol, gives rise to triterpenes, sterols, and most sesquiterpenes.",
BMGC_PW0108,BMG_PW0183,"Those metabolic reactions involved in the degradation of limonene -  an essential oil, a monocyclic terpene, found in the peel of oranges and lemons, and pinene - a terpene found in turpentine and many essential oils, used as a solvent and in the manufacture of camphor, insecticides, and synthetic pine oil. [KEGG:map00903, OneLook:www.onelook.com]",,
BMGC_PW0109,BMG_PW0184,"Those metabolic reactions involved in the synthesis of streptomycin - the first of the aminoglycoside antibiotics to be isolated, derived from Streptomyces griseus; it is effective against a wide variety of aerobic gram-negative bacilli and some gram-positive bacteria, including mycobacteria. Its use is now limited because of the emergence of resistant strains. [GO:0019872, KEGG:map00521, OneLook:www.onelook.com]",,
BMGC_PW0110,BMG_PW0188,"Those reactions involved in the synthesis, utilization and/or degradation of porphyrin - any of a group of compounds containing the porphyrin structure, four pyrrole rings connected by methine bridges in a cyclic configuration, to which a variety of side chains may be attached - and chlorophyll - any of a group of green magnesium-containing porphyrin derivatives occurring in all photosynthetic organisms. [KEGG:map00860, OneLook:www.onelook.com]","Porphyrins are a group of chemical compounds with the backbone ring structure consisting of four linked pyrrole units. Metal complexes of porphyrins, as well as those of corrinoids with the one-carbon shorter ring structure, play important biological roles. They include iron-containing heme, magnesium-containing chlorophyll, nickel-containing coenzyme F430 and cobalt-containing cobamide (such as vitamin B12 coenzyme) as shown in this map.",
BMGC_PW0111,BMG_PW0189,"Those metabolic reactions involved in the biosynthesis of keratan sulfate - a glycosaminoglycan found in the cornea, in cartilage, and in the nucleus pulposus and also as the accumulation product in Morquio's syndrome. It consists of repeating disaccharide units in specific linkage, each composed of a sulfated N-acetylglucosamine residue linked to one of galactose, which is usually sulfated. There are two forms, keratan sulfate I and keratan sulfate II, which differ in carbohydrate content and localization; the former occurs in the cornea and the latter in skeletal tissues. [GO:0018146, KEGG:map00533, OneLook:www.onelook.com, Reactome:R-HSA-2022854]","Keratan sulfate (KS) is a glycosaminoglycan with the basic disaccharide unit of N-acetyllactosamine, Gal(b1-4)GlcNAc(b1-3), with sulfate esters at C-6 of GlcNAc and Gal residues. There are two types of KS distinguished by the protein linkage: type I for N-linked via the N-glycan core structure and type II for O-linked via the O-glycan core 2 structure.","Keratan sulfate (KSI) is the best characterised keratan sulfate. It is 10 times more abundant in cornea than cartilage. KSI is attached to an asparagine (Asn) residue on the core protein via an N-linked branched oligosaccharide (an N-glycan core structure used as a precursor in N-glycan biosynthesis). KSI is elongated by the alternate additions of galactose (Gal) and N-acetylglucosamine (GlcNAc), mediated by glycosyltransferases. Elongation is terminated by the addition of a single N-acetylneuraminic acid (sialyl) residue. KSI is also sulfated on Gal and GlcNAc residues by at least two sulfotransferases (Funderburgh 2000, Funderburgh 2002, Quantock et al. 2010). KSI can be attached to asparagine residues on core proteins, creating so called proteoglycans (PGs). Seven common core proteins found in corneal and skeletal tissues are used as examples here."
BMGC_PW0112,BMG_PW0190,"Those metabolic reactions involved in the synthesis of N-linked glycans. A 14 residue sugar is first built on a dolichol carrier and then attached to the amide group of an asparagine of a nascent polypeptide chain. The asparagine is in a specific amino acid sequence. Subsequent processing involves removal as well as addition of various sugars and produces a wide range of N-glycan structures. [KEGG:map00510, MCW_Libraries:QU4_V876f_2008]","N-glycans or asparagine-linked glycans are major constituents of glycoproteins in eukaryotes. N-glycans are covalently attached to asparagine with the consensus sequence of Asn-X-Ser/Thr by an N-glycosidic bond, GlcNAc b1- Asn. Biosynthesis of N-glycans begins on the cytoplasmic face of the ER membrane with the transferase reaction of UDP-GlcNAc and the lipid-like precursor P-Dol (dolichol phosphate) to generate GlcNAc a1- PP-Dol. After sequential addition of monosaccharides by ALG glycosyltransferases [MD:M00055], the N-glycan precursor is attached by the OST (oligosaccharyltransferase) complex to the polypeptide chain that is being synthesized and translocated through the ER membrane. The protein-bound N-glycan precursor is subsequently trimmed, extended, and modified in the ER and Golgi by a complex series of reactions catalyzed by membrane-bound glycosidases and glycosyltransferases. N-glycans thus synthesized are classified into three types: high-mannose type, complex type, and hybrid type. Defects in N-glycan biosynthesis lead to a variety of human diseases known as congenital disorders of glycosylation [DS:H00118 H00119].",
BMGC_PW0113,BMG_PW0192,"Those metabolic reactions involved in the synthesis of O-linked glycans. Sugars are serially added to a fully synthesized polypeptide chain. The initial step involves the transfer of N-acetylgalactosamine to the carboxy group of a serine or threonine. The location of the residue appears to be dictated by structure rather than amino acid signature. [KEGG:map00512, MCW_Libraries:QU4_V876f]","O-glycans are a class of glycans that modify serine or threonine residues of proteins. Biosynthesis of O-glycans starts from the transfer of N-acetylgalactosamine (GalNAc) to serine or threonine. The first GalNAc may be extended with sugars including galactose, N-acetylglucosamine, fucose, or sialic acid, but not mannose, glucose, or xylose. Depending on the sugars added, there are four common O-glycan core structures, cores 1 through 4, and an additional four, cores 5 though 8. Mucins are highly O-glycosylated glycoproteins ubiquitous in mucous secretions on cell surfaces and in body fluids. Mucin O-glycans can be branched, and many sugars or groups of sugars are antigenic. Important modifications of mucin O-glycans include O-acetylation of sialic acid and O-sulfation of galactose and N-acetylglucosamine.",
BMGC_PW0114,BMG_PW0193,"Those metabolic reactions involved in the biosynthesis of chondroitin. Chondroitin is a mucopolysaccharide occurring in sulfated form in various animal tissues (such as cartilage). [GO:0030206, KEGG:map00532, OneLook:www.onelook.com, Reactome:R-HSA-2022870]","Glycosaminoglycans (GAGs) are linear polysaccharide chains consisting of repeating disaccharide units and form proteglycans by covalently attaching to their core proteins. Chondroitin sulfate (CS) is a glycosaminoglycan with the disaccharide unit of beta-D-galactosamine (GalNAc) and beta-D-glucuronic acid (GlcA), and often modified with ester-linked sulfate at certain positions. Dermatan sulfate (DS) is a modified form of CS, in which a portion of D-glucuronate residues is epimerized to L-iduronates (IdoA). CS and DS are linked to serine residues in core proteins via a linkage tetrasaccharide formed by the transfer of xylose and three more residues [MD:M00057]. The assembly process of CS is initiated by transferring GalNAc residue to the linkage tetrasaccharide. The polymerization is catalyzed by bifunctional enzymes (chondroitin synthases) possessing both beta 1,3 glucuronosyltransferase and beta 1,4 N-acetylgalactosaminyltransferase activities [MD:M00058]. Chondroitin polymerization also requires the action of the chondroitin polymerizing factor. There are various O-sulfation patterns in CS and DS, where 4-O sulfation and 6-O sulfation of GalNAc and 2-O-sulfation of the uronic acids (GlcA / IdoA) are mainly found.","Chondroitin sulfate (CS) glycosaminoglycan consists of N-acetylgalactosamine (GalNAc) residues alternating in glycosidic linkages with glucuronic acid (GlcA). GalNAc residues are sulfated to varying degrees on 4- and/or 6- positions. The steps below describe the biosynthesis of a simple CS molecule (Pavao et al. 2006, Silbert & Sugumaran 2002)."
BMGC_PW0115,BMG_PW0194,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of globosides - glycosphingolipids containing acetylated amino sugars and simple hexoses. [GO:0001575, KEGG:00603, OneLook:www.onelook.com]",,
BMGC_PW0116,BMG_PW0195,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of sphingolipids - important components of animal and plant membranes. They contain a long chain amino alcohol and a ceramide core. Ceramides are also the precursors of glycolipids, also referred to as glycosphingolipids, which have attached sugar(s). [GO:0006665, KEGG:00600, MCW_library:QU4_M235b_2009, OneLook:www.onelook.com, PMID:17976918, Reactome:R-HSA-428157, SMP:00034]",,"Sphingolipids are derivatives of long chain sphingoid bases such as sphingosine (trans-1,3-dihydroxy 2-amino-4-octadecene), an 18-carbon unsaturated amino alcohol which is the most abundant sphingoid base in mammals. Amide linkage of a fatty acid to sphingosine yields ceramides. Esterification of phosphocholine to ceramides yields sphingomyelin, and ceramide glycosylation yields glycosylceramides. Introduction of sialic acid residues yields gangliosides. These molecules appear to be essential components of cell membranes, and intermediates in the pathways of sphingolipid synthesis and breakdown modulate processes including apoptosis and T cell trafficking. While sphingolipids are abundant in a wide variety of foodstuffs, these dietary molecules are mostly degraded by the intestinal flora and intestinal enzymes. The body primarily depends on de novo synthesis for its sphingolipid supply (Hannun and Obeid 2008; Merrill 2002). De novo synthesis proceeds in four steps: the condensation of palmitoyl-CoA and serine to form 3-ketosphinganine, the reduction of 3-ketosphinganine to sphinganine, the acylation of sphinganine with a long-chain fatty acyl CoA to form dihydroceramide, and the desaturation of dihydroceramide to form ceramide. Other sphingolipids involved in signaling are derived from ceramide and its biosynthetic intermediates. These include sphinganine (dihydrosphingosine) 1-phosphate, phytoceramide, sphingosine, and sphingosine 1-phosphate. Sphingomyelin is synthesized in a single step in the membrane of the Golgi apparatus from ceramides generated in the endoplasmic reticulum (ER) membrane and transferred to the Golgi by CERT (ceramide transfer protein), an isoform of COL4A3BP that is associated with the ER membrane as a complex with PPM1L (protein phosphatase 1-like) and VAPA or VAPB (VAMP-associated proteins A or B). Sphingomyelin synthesis appears to be regulated primarily at the level of this transport process through the reversible phosphorylation of CERT (Saito et al. 2008)."
BMGC_PW0117,BMG_PW0196,"A SAPK MAPK pathway that plays an important role in inflammation and may be involved in several forms of cancer. [GO:0051403, KEGG:map04010, PID:200018, PMID:14570565, PMID:15102355, Reactome:R-HSA-171007]","The mitogen-activated protein kinase (MAPK) cascade is a highly conserved module that is involved in various cellular functions, including cell proliferation, differentiation and migration. Mammals express at least four distinctly regulated groups of MAPKs, extracellular signal-related kinases (ERK)-1/2, Jun amino-terminal kinases (JNK1/2/3), p38 proteins (p38alpha/beta/gamma/delta) and ERK5, that are activated by specific MAPKKs: MEK1/2 for ERK1/2, MKK3/6 for the p38, MKK4/7 (JNKK1/2) for the JNKs, and MEK5 for ERK5. Each MAPKK, however, can be activated by more than one MAPKKK, increasing the complexity and diversity of MAPK signalling. Presumably each MAPKKK confers responsiveness to distinct stimuli. For example, activation of ERK1/2 by growth factors depends on the MAPKKK c-Raf, but other MAPKKKs may activate ERK1/2 in response to pro-inflammatory stimuli.","NGF induces sustained activation of p38, a member of the MAPK family (Morooka T, Nishida E, 1998). Both p38 and the ERKs appear to be involved in neurite outgrowth and differentiation caused by NGF in PC12 cells. As a matter of fact, PC12 cell differentiation appears to involve activation of both ERK/MAPK and p38. Both ERK/MAPK and p38 pathways contribute to the phosphorylation of the transcription factor CREB and the activation of immediate-early genes (Xing J, 1998). p38 activation by NGF may occur by at least two mechanisms, involving SRC or MEK kinases."
BMGC_PW0118,BMG_PW0197,"A Wnt mediated pathway that is involved in the regulation of cell-cell adhesion and motility. [GO:0007223, KEGG:map04310, PMID:10858654, PMID:12573432]","Wnt proteins are secreted morphogens that are required for basic developmental processes, such as cell-fate specification, progenitor-cell proliferation and the control of asymmetric cell division, in many different species and organs. There are at least three different Wnt pathways: the canonical pathway, the planar cell polarity (PCP) pathway and the Wnt/Ca2+ pathway. In the canonical Wnt pathway, the major effect of Wnt ligand binding to its receptor is the stabilization of cytoplasmic beta-catenin through inhibition of the bea-catenin degradation complex. Beta-catenin is then free to enter the nucleus and activate Wnt-regulated genes through its interaction with TCF (T-cell factor) family transcription factors and concomitant recruitment of coactivators. Planar cell polarity (PCP) signaling leads to the activation of the small GTPases RHOA (RAS homologue gene-family member A) and RAC1, which activate the stress kinase JNK (Jun N-terminal kinase) and ROCK (RHO-associated coiled-coil-containing protein kinase 1) and leads to remodelling of the cytoskeleton and changes in cell adhesion and motility. WNT-Ca2+ signalling is mediated through G proteins and phospholipases and leads to transient increases in cytoplasmic free calcium that subsequently activate the kinase PKC (protein kinase C) and CAMKII (calcium calmodulin mediated kinase II) and the phosphatase calcineurin.","WNT signaling pathways control a wide range of developmental and adult process in metozoans including cell proliferation, cell fate decisions, cell polarity and stem cell maintenance (reviewed in Saito-Diaz et al, 2013; MacDonald et al, 2009). The pathway is named for the WNT ligands, a large family of secreted cysteine-rich glycoproteins. At least 19 WNT members have been identified in humans and mice with distinct expression patterns during development (reviewed in Willert and Nusse, 2012). These ligands can activate at least three different downstream signaling cascades depending on which receptors they engage. In the so-called 'canonical' WNT signaling pathway, WNT ligands bind one of the 10 human Frizzled (FZD) receptors in conjunction with the LRP5/6 co-receptors to activate a transcriptional cascade that controls processes such as cell fate, proliferation and self-renenwal of stem cells. Engagement of the FZD-LRP receptor by WNT ligand results in the stabilization and translocation of cytosolic beta-catenin to the nucleus where it is a co-activator for LEF (lymphoid enhancer-binding factor)- and TCF (T cell factor) -dependent transcription. In the absence of WNT ligand, cytosolic beta-catenin is phosphorylated by a degradation complex consisting of glycogen synthase kinase 3 (GSK3), casein kinase 1 (CK1), Axin and Adenomatous polyposis coli (APC), and subsequently ubiquitinated and degraded by the 26S proteasome (reviewed in Saito-Diaz et al, 2013; Kimmelman and Xu, 2006). In addition to the beta-catenin-dependent transcriptional response, WNT signaling can also activate distinct non-transcriptional pathways that regulate cell migration and polarity. These beta-catenin-independent 'non-canonical' pathways signal through Frizzled receptors independently of LRP5/6, or occur through the tyrosine kinase receptors ROR and RYK (reviewed in Veeman et al, 2003; James et al, 2009). Non-canonical WNT pathways are best studied in Drosophila where the planar cell polarity (PCP) pathway controls the orientation of wing hairs and eye facets, but are also involved in processes such as convergent extension, neural tube closure, inner ear development and hair orientation in vertebrates and mammals(reviewed in Seifert and Mlodzik, 2007; Simons and Mlodzik, 2008). In the PCP pathway, binding of WNT ligand to the FZD receptor leads to activation of small Rho GTPases and JNK, which regulate the cytoskeleton and coordinate cell migration and polarity (reviewed in Lai et al, 2009; Schlessinger et al, 2009). In some cases, a FZD-WNT interaction increases intracellular calcium concentration and activates CaMK II and PKC; this WNT calcium pathway promotes cell migration and inhibits the canonical beta-catenin dependent transcriptional pathway (reviewed in Kuhl et al, 2000; Kohn and Moon, 2005; Rao et al 2010). Binding of WNT to ROR or RYK receptors also regulates cell migration, apparently through activation of JNK or SRC kinases, respectively, however the details of these pathways remain to be worked out (reviewed in Minami et al, 2010). Although the WNT signaling pathways were originally viewed as discrete, linear pathways controlled by defined subsets of 'canonical' or 'non-canonical' ligands and receptors, the emerging evidence is challenging this notion. Instead, the specificity and the downstream response appear to depend on the particular cellular context and vary with species, tissue and stage of development (reviewed in van Amerongen and Nusse, 2009; Rao et al, 2010)."
BMGC_PW0119,BMG_PW0198,"The planar cell polarity (PCP) Wnt signaling pathway plays an essential role in morphogenesis through the regulation of tissues patterning. [GO:0060071, KEGG:map04310, PMID:12573432, PMID:16765615]","Wnt proteins are secreted morphogens that are required for basic developmental processes, such as cell-fate specification, progenitor-cell proliferation and the control of asymmetric cell division, in many different species and organs. There are at least three different Wnt pathways: the canonical pathway, the planar cell polarity (PCP) pathway and the Wnt/Ca2+ pathway. In the canonical Wnt pathway, the major effect of Wnt ligand binding to its receptor is the stabilization of cytoplasmic beta-catenin through inhibition of the bea-catenin degradation complex. Beta-catenin is then free to enter the nucleus and activate Wnt-regulated genes through its interaction with TCF (T-cell factor) family transcription factors and concomitant recruitment of coactivators. Planar cell polarity (PCP) signaling leads to the activation of the small GTPases RHOA (RAS homologue gene-family member A) and RAC1, which activate the stress kinase JNK (Jun N-terminal kinase) and ROCK (RHO-associated coiled-coil-containing protein kinase 1) and leads to remodelling of the cytoskeleton and changes in cell adhesion and motility. WNT-Ca2+ signalling is mediated through G proteins and phospholipases and leads to transient increases in cytoplasmic free calcium that subsequently activate the kinase PKC (protein kinase C) and CAMKII (calcium calmodulin mediated kinase II) and the phosphatase calcineurin.","WNT signaling pathways control a wide range of developmental and adult process in metozoans including cell proliferation, cell fate decisions, cell polarity and stem cell maintenance (reviewed in Saito-Diaz et al, 2013; MacDonald et al, 2009). The pathway is named for the WNT ligands, a large family of secreted cysteine-rich glycoproteins. At least 19 WNT members have been identified in humans and mice with distinct expression patterns during development (reviewed in Willert and Nusse, 2012). These ligands can activate at least three different downstream signaling cascades depending on which receptors they engage. In the so-called 'canonical' WNT signaling pathway, WNT ligands bind one of the 10 human Frizzled (FZD) receptors in conjunction with the LRP5/6 co-receptors to activate a transcriptional cascade that controls processes such as cell fate, proliferation and self-renenwal of stem cells. Engagement of the FZD-LRP receptor by WNT ligand results in the stabilization and translocation of cytosolic beta-catenin to the nucleus where it is a co-activator for LEF (lymphoid enhancer-binding factor)- and TCF (T cell factor) -dependent transcription. In the absence of WNT ligand, cytosolic beta-catenin is phosphorylated by a degradation complex consisting of glycogen synthase kinase 3 (GSK3), casein kinase 1 (CK1), Axin and Adenomatous polyposis coli (APC), and subsequently ubiquitinated and degraded by the 26S proteasome (reviewed in Saito-Diaz et al, 2013; Kimmelman and Xu, 2006). In addition to the beta-catenin-dependent transcriptional response, WNT signaling can also activate distinct non-transcriptional pathways that regulate cell migration and polarity. These beta-catenin-independent 'non-canonical' pathways signal through Frizzled receptors independently of LRP5/6, or occur through the tyrosine kinase receptors ROR and RYK (reviewed in Veeman et al, 2003; James et al, 2009). Non-canonical WNT pathways are best studied in Drosophila where the planar cell polarity (PCP) pathway controls the orientation of wing hairs and eye facets, but are also involved in processes such as convergent extension, neural tube closure, inner ear development and hair orientation in vertebrates and mammals(reviewed in Seifert and Mlodzik, 2007; Simons and Mlodzik, 2008). In the PCP pathway, binding of WNT ligand to the FZD receptor leads to activation of small Rho GTPases and JNK, which regulate the cytoskeleton and coordinate cell migration and polarity (reviewed in Lai et al, 2009; Schlessinger et al, 2009). In some cases, a FZD-WNT interaction increases intracellular calcium concentration and activates CaMK II and PKC; this WNT calcium pathway promotes cell migration and inhibits the canonical beta-catenin dependent transcriptional pathway (reviewed in Kuhl et al, 2000; Kohn and Moon, 2005; Rao et al 2010). Binding of WNT to ROR or RYK receptors also regulates cell migration, apparently through activation of JNK or SRC kinases, respectively, however the details of these pathways remain to be worked out (reviewed in Minami et al, 2010). Although the WNT signaling pathways were originally viewed as discrete, linear pathways controlled by defined subsets of 'canonical' or 'non-canonical' ligands and receptors, the emerging evidence is challenging this notion. Instead, the specificity and the downstream response appear to depend on the particular cellular context and vary with species, tissue and stage of development (reviewed in van Amerongen and Nusse, 2009; Rao et al, 2010)."
BMGC_PW0120,BMG_PW0199,"The Wnt signaling pathway is involved in many developmental processes. In the conventional or canonical Wnt pathway, beta-catenin is a central component required for the transcriptional control of Wnt signaling target genes. [GO:0060070, KEGG:map04310, PID:200077, PMID:12573432, PMID:15001769, PMID:18432252, Reactome:REACT_11045.1]","Wnt proteins are secreted morphogens that are required for basic developmental processes, such as cell-fate specification, progenitor-cell proliferation and the control of asymmetric cell division, in many different species and organs. There are at least three different Wnt pathways: the canonical pathway, the planar cell polarity (PCP) pathway and the Wnt/Ca2+ pathway. In the canonical Wnt pathway, the major effect of Wnt ligand binding to its receptor is the stabilization of cytoplasmic beta-catenin through inhibition of the bea-catenin degradation complex. Beta-catenin is then free to enter the nucleus and activate Wnt-regulated genes through its interaction with TCF (T-cell factor) family transcription factors and concomitant recruitment of coactivators. Planar cell polarity (PCP) signaling leads to the activation of the small GTPases RHOA (RAS homologue gene-family member A) and RAC1, which activate the stress kinase JNK (Jun N-terminal kinase) and ROCK (RHO-associated coiled-coil-containing protein kinase 1) and leads to remodelling of the cytoskeleton and changes in cell adhesion and motility. WNT-Ca2+ signalling is mediated through G proteins and phospholipases and leads to transient increases in cytoplasmic free calcium that subsequently activate the kinase PKC (protein kinase C) and CAMKII (calcium calmodulin mediated kinase II) and the phosphatase calcineurin.","WNT signaling pathways control a wide range of developmental and adult process in metozoans including cell proliferation, cell fate decisions, cell polarity and stem cell maintenance (reviewed in Saito-Diaz et al, 2013; MacDonald et al, 2009). The pathway is named for the WNT ligands, a large family of secreted cysteine-rich glycoproteins. At least 19 WNT members have been identified in humans and mice with distinct expression patterns during development (reviewed in Willert and Nusse, 2012). These ligands can activate at least three different downstream signaling cascades depending on which receptors they engage. In the so-called 'canonical' WNT signaling pathway, WNT ligands bind one of the 10 human Frizzled (FZD) receptors in conjunction with the LRP5/6 co-receptors to activate a transcriptional cascade that controls processes such as cell fate, proliferation and self-renenwal of stem cells. Engagement of the FZD-LRP receptor by WNT ligand results in the stabilization and translocation of cytosolic beta-catenin to the nucleus where it is a co-activator for LEF (lymphoid enhancer-binding factor)- and TCF (T cell factor) -dependent transcription. In the absence of WNT ligand, cytosolic beta-catenin is phosphorylated by a degradation complex consisting of glycogen synthase kinase 3 (GSK3), casein kinase 1 (CK1), Axin and Adenomatous polyposis coli (APC), and subsequently ubiquitinated and degraded by the 26S proteasome (reviewed in Saito-Diaz et al, 2013; Kimmelman and Xu, 2006). In addition to the beta-catenin-dependent transcriptional response, WNT signaling can also activate distinct non-transcriptional pathways that regulate cell migration and polarity. These beta-catenin-independent 'non-canonical' pathways signal through Frizzled receptors independently of LRP5/6, or occur through the tyrosine kinase receptors ROR and RYK (reviewed in Veeman et al, 2003; James et al, 2009). Non-canonical WNT pathways are best studied in Drosophila where the planar cell polarity (PCP) pathway controls the orientation of wing hairs and eye facets, but are also involved in processes such as convergent extension, neural tube closure, inner ear development and hair orientation in vertebrates and mammals(reviewed in Seifert and Mlodzik, 2007; Simons and Mlodzik, 2008). In the PCP pathway, binding of WNT ligand to the FZD receptor leads to activation of small Rho GTPases and JNK, which regulate the cytoskeleton and coordinate cell migration and polarity (reviewed in Lai et al, 2009; Schlessinger et al, 2009). In some cases, a FZD-WNT interaction increases intracellular calcium concentration and activates CaMK II and PKC; this WNT calcium pathway promotes cell migration and inhibits the canonical beta-catenin dependent transcriptional pathway (reviewed in Kuhl et al, 2000; Kohn and Moon, 2005; Rao et al 2010). Binding of WNT to ROR or RYK receptors also regulates cell migration, apparently through activation of JNK or SRC kinases, respectively, however the details of these pathways remain to be worked out (reviewed in Minami et al, 2010). Although the WNT signaling pathways were originally viewed as discrete, linear pathways controlled by defined subsets of 'canonical' or 'non-canonical' ligands and receptors, the emerging evidence is challenging this notion. Instead, the specificity and the downstream response appear to depend on the particular cellular context and vary with species, tissue and stage of development (reviewed in van Amerongen and Nusse, 2009; Rao et al, 2010)."
BMGC_PW0121,BMG_PW0200,"A specific pathway for repair of double-strand breaks. It is involved in repair of breaks induced by damaging agents or generated during meiotic recombination. [GO:0000724, KEGG:03440, PMID:24326623, Reactome:R-HSA-5693538]","Homologous recombination (HR) is essential for the accurate repair of DNA double-strand breaks (DSBs), potentially lethal lesions. HR takes place in the late S-G2 phase of the cell cycle and involves the generation of a single-stranded region of DNA, followed by strand invasion, formation of a Holliday junction, DNA synthesis using the intact strand as a template, branch migration and resolution. It is investigated that RecA/Rad51 family proteins play a central role. The breast cancer susceptibility protein Brca2 and the RecQ helicase BLM (Bloom syndrome mutated) are tumor suppressors that maintain genome integrity, at least in part, through HR.",
BMGC_PW0122,BMG_PW0201,"A specific pathway for repair of double-strand breaks. Possibly constitutive, it is the most important pathway in mammalian cells and plays an important role in mitotically replicating cells. [GO:0006303, PMID:12947387, Reactome:R-HSA-5693571]","Nonhomologous end joining (NHEJ) eliminates DNA double-strand breaks (DSBs) by direct ligation. NHEJ involves binding of the KU heterodimer to double-stranded DNA ends, recruitment of DNA-PKcs (MRX complex in yeast), processing of ends, and recruitment of the DNA ligase IV (LIG4)-XRCC4 complex, which brings about ligation. A recent study shows that bacteria accomplish NHEJ using just two proteins (Ku and DNA ligase), whereas eukaryotes require many factors. NHEJ repairs DSBs at all stages of the cell cycle, bringing about the ligation of two DNA DSBs without the need for sequence homology, and so is error-prone.",
BMGC_PW0123,BMG_PW0202,"The Notch signaling pathway regulates processes involved in early embryonic development. It plays an important role in cell fate determination. Target genes of Notch have been implicated in angiogenesis, somitogenesis and gliogenesis. Deregulation of the Notch signaling pathway underlies a broad spectrum of diseases and clinical conditions. [GO:0007219, KEGG:map04330, PID:200015, PubMed:Several_articles_in_PubMed, Reactome:R-HSA-157118]","The Notch signaling pathway is an evolutionarily conserved, intercellular signaling mechanism essential for proper embryonic development in all metazoan organisms in the Animal kingdom. The Notch proteins (Notch1-Notch4 in vertebrates) are single-pass receptors that are activated by the Delta (or Delta-like) and Jagged/Serrate families of membrane-bound ligands. They are transported to the plasma membrane as cleaved, but otherwise intact polypeptides. Interaction with ligand leads to two additional proteolytic cleavages that liberate the Notch intracellular domain (NICD) from the plasma membrane. The NICD translocates to the nucleus, where it forms a complex with the DNA binding protein CSL, displacing a histone deacetylase (HDAc)-co-repressor (CoR) complex from CSL. Components of an activation complex, such as MAML1 and histone acetyltransferases (HATs), are recruited to the NICD-CSL complex, leading to the transcriptional activation of Notch target genes.","The Notch Signaling Pathway (NSP) is a highly conserved pathway for cell-cell communication. NSP is involved in the regulation of cellular differentiation, proliferation, and specification. For example, it is utilised by continually renewing adult tissues such as blood, skin, and gut epithelium not only to maintain stem cells in a proliferative, pluripotent, and undifferentiated state but also to direct the cellular progeny to adopt different developmental cell fates. Analogously, it is used during embryonic development to create fine-grained patterns of differentiated cells, notably during neurogenesis where the NSP controls patches such as that of the vertebrate inner ear where individual hair cells are surrounded by supporting cells. This process is known as lateral inhibition: a molecular mechanism whereby individual cells within a field are stochastically selected to adopt particular cell fates and the NSP inhibits their direct neighbours from doing the same. The NSP has been adopted by several other biological systems for binary cell fate choice. In addition, the NSP is also used during vertebrate segmentation to divide the growing embryo into regular blocks called somites which eventually form the vertebrae. The core of this process relies on regular pulses of Notch signaling generated from a molecular oscillator in the presomatic mesoderm. The Notch receptor is synthesized in the rough endoplasmic reticulum as a single polypeptide precursor. Newly synthesized Notch receptor is proteolytically cleaved in the trans-golgi network, creating a heterodimeric mature receptor comprising of non-covalently associated extracellular and transmembrane subunits. This assembly travels to the cell surface ready to interact with specific ligands. Following ligand activation and further proteolytic cleavage, an intracellular domain is released and translocates to the nucleus where it regulates gene expression."
BMGC_PW0124,BMG_PW0204,"The transforming growth factor-beta (TGF-beta) signaling pathway regulates numerous cellular processes such as proliferation, differentiation, migration and cell death. The SMAD-dependent pathway represents the core signaling cascade mediated by the TGF-beta superfamily. Mutations in the TGF-beta family are responsible for a number of human diseases. [GO:0007179, PMID:15130563, PMID:16678165, PubMed:TIBS\,_2004\,_v29_(5)\,_p265-273, Reactome:R-HSA-170834]",,"The TGF-beta/BMP pathway incorporates several signaling pathways that share most, but not all, components of a central signal transduction engine. The general signaling scheme is rather simple: upon binding of a ligand, an activated plasma membrane receptor complex is formed, which passes on the signal towards the nucleus through a phosphorylated receptor SMAD (R-SMAD). In the nucleus, the activated R-SMAD promotes transcription in complex with a closely related helper molecule termed Co-SMAD (SMAD4). However, this simple linear pathway expands into a network when various regulatory components and mechanisms are taken into account. The signaling pathway includes a great variety of different TGF-beta/BMP superfamily ligands and receptors, several types of the R-SMADs, and functionally critical negative feedback loops. The R-SMAD:Co-SMAD complex can interact with a great number of transcriptional co-activators/co-repressors to regulate positively or negatively effector genes, so that the interpretation of a signal depends on the cell-type and cross talk with other signaling pathways such as Notch, MAPK and Wnt. The pathway plays a number of different biological roles in the control of embryonic and adult cell proliferation and differentiation, and it is implicated in a great number of human diseases. TGF beta (TGFB1) is secreted as a homodimer, and as such it binds to TGF beta receptor II (TGFBR2), inducing its dimerization. Binding of TGF beta enables TGFBR2 to form a stable hetero-tetrameric complex with TGF beta receptor I homodimer (TGFBR1). TGFBR2 acts as a serine/threonine kinase and phosphorylates serine and threonine residues within the short GS domain (glycine-serine rich domain) of TGFBR1. The phosphorylated heterotetrameric TGF beta receptor complex (TGFBR) internalizes into clathrin coated endocytic vesicles where it associates with the endosomal membrane protein SARA. SARA facilitates the recruitment of cytosolic SMAD2 and SMAD3, which act as R-SMADs for TGF beta receptor complex. TGFBR1 phosphorylates recruited SMAD2 and SMAD3, inducing a conformational change that promotes formation of R-SMAD trimers and dissociation of R-SMADs from the TGF beta receptor complex. In the cytosol, phosphorylated SMAD2 and SMAD3 associate with SMAD4 (known as Co-SMAD), forming a heterotrimer which is more stable than the R-SMAD homotrimers. R-SMAD:Co-SMAD heterotrimer translocates to the nucleus where it directly binds DNA and, in cooperation with other transcription factors, regulates expression of genes involved in cell differentiation, in a context-dependent manner. The intracellular level of SMAD2 and SMAD3 is regulated by SMURF ubiquitin ligases, which target R-SMADs for degradation. In addition, nuclear R-SMAD:Co-SMAD heterotrimer stimulates transcription of inhibitory SMADs (I-SMADs), forming a negative feedback loop. I-SMADs bind the phosphorylated TGF beta receptor complexes on caveolin coated vesicles, derived from the lipid rafts, and recruit SMURF ubiquitin ligases to TGF beta receptors, leading to ubiquitination and degradation of TGFBR1. Nuclear R-SMAD:Co-SMAD heterotrimers are targets of nuclear ubiquitin ligases which ubiquitinate SMAD2/3 and SMAD4, causing heterotrimer dissociation, translocation of ubiquitinated SMADs to the cytosol and their proteasome-mediated degradation. For a recent review of TGF-beta receptor signaling, please refer to Kang et al. 2009."
BMGC_PW0125,BMG_PW0206,"Diabetes mellitus is characterized by abnormally high levels of glucose in the blood. Hereditary and environmental factors are likely contributors but the exact mechanisms are not well understood. Type 2 diabetes mellitus, characterized by insulin resistance, involves alterations in insulin secretion and signaling and impaired glucose homeostasis pathways. [KEGG:map04930, OneLook:www.onelook.com]","Insulin resistance is strongly associated with type II diabetes. ""Diabetogenic"" factors including FFA, TNFalpha and cellular stress induce insulin resistance through inhibition of IRS1 functions. Serine/threonine phosphorylation, interaction with SOCS, regulation of the expression, modification of the cellular localization, and degradation represent the molecular mechanisms stimulated by them. Various kinases (ERK, JNK, IKKbeta, PKCzeta, PKCtheta and mTOR) are involved in this process.             The development of type II diabetes requires impaired beta-cell function. Chronic hyperglycemia has been shown to induce multiple defects in beta-cells. Hyperglycemia has been proposed to lead to large amounts of reactive oxygen species (ROS) in beta-cells, with subsequent damage to cellular components including PDX-1. Loss of PDX-1, a critical regulator of insulin promoter activity, has also been proposed as an important mechanism leading to beta-cell dysfunction.             Although there is little doubt as to the importance of genetic factors in type II diabetes, genetic analysis is difficult due to complex interaction among multiple susceptibility genes and between genetic and environmental factors. Genetic studies have therefore given very diverse results. Kir6.2 and IRS are two of the candidate genes. It is known that Kir6.2 and IRS play central roles in insulin secretion and insulin signal transmission, respectively.",
BMGC_PW0126,BMG_PW0207,"The Jak-Stat pathway is a main intracellular cascade initiated primarily in response to cytokine and also other ligand signaling. Four Janus kinases (Jak) and seven signal transducers and activators of transcription (Stat) families of proteins mediate the action of almost 40 cytokine receptors, including the receptor for leptin. Combinations between four Jak(s) and seven Stat(s) shape the outcome of ligand- triggered signaling through the various receptors. [GO:0007259, KEGG:map04630, MCW_library:Handbook_of_cellular_and_molecular_immunology, PMID:12039028, PMID:14668806, PMID:14737178, PMID:17312100]","The Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway is one of a handful of pleiotropic cascades used to transduce a multitude of signals for development and homeostasis in animals, from humans to flies. In mammals, the JAK/STAT pathway is the principal signaling mechanism for a wide array of cytokines and growth factors. Following the binding of cytokines to their cognate receptor, STATs are activated by members of the JAK family of tyrosine kinases. Once activated, they dimerize and translocate to the nucleus and modulate the expression of target genes. In addition to the activation of STATs, JAKs mediate the recruitment of other molecules such as the MAP kinases, PI3 kinase etc. These molecules process downstream signals via the Ras-Raf-MAP kinase and PI3 kinase pathways which results in the activation of additional transcription factors.",
BMGC_PW0127,BMG_PW0212,"Polyamines play important roles in cell growth, proliferation and survival. They can be derived from diet as well as via cellular- and intestinal flora-mediated biosynthesis. [GO:0006595, PMID:19603518, Reactome:R-HSA-351202]",,"Polyamines is a family of molecules (i.e. putrescine, spermine, spermidine) derived from ornithine according to a decarboxylation/condensative process. More recently, it has been demonstrated that arginine can be metabolised according to the same pathway leading to agmatine formation. Polyamines are essential for the growth, the maintenance and the function of normal cells. The complexity of their metabolism and the fact that polyamines homeostasis is tightly regulated support the idea that polyamines are essential to cell survival. Multiple abnormalities in the control of polyamines metabolism might be implicated in several pathological processes (Moinard et al., 2005). Legend for the following figure:"
BMGC_PW0128,BMG_PW0216,"Those metabolic reactions involved in the biosynthesis of heme - an iron-containing compound where the iron is complexed within a porphyrin heterocyclic ring. There are several kinds of heme depending on the composition of their side chain. Heme serves as a prosthetic group for several classes of proteins that include hemoglobin and myoglobin, cytochromes, peroxidases, catalases and others. [GO:0006783, PMID:26785297, Reactome:R-HSA-189451]",,"Although heme is synthesised in virtually all tissues, the principal sites of synthesis are erythroid cells (~85%) and hepatocytes (most of the remainder). Eight enzymes are involved in heme biosynthesis, four each in the mitochondria and the cytosol (Layer et al. 2010). The process starts in the mitochondria with the condensation of succinyl CoA (from the TCA cycle) and glycine to form 5-aminolevulinate (ALA). The next four steps take place in the cytosol. Two molecules of ALA are condensed to form the monopyrrole porphobilinogen (PBG). The next two steps convert four molecules of PBG into the cyclic tetrapyrrole uroporphyringen III, which is then decarboxylated into coproporphyrinogen III. The last three steps occur in the mitochondria and involve modifications to the tetrapyrrole side chains and finally, insertion of iron. In addition to these synthetic steps, a spontaneous cytosolic reaction allows the formation of uroporphyringen I which is then enzymatically decarboxylated to coproporphyrinogen I, which cannot be metabolized further in humans. Also, lead can inactivate ALAD, the enzyme that catalyzes PBG synthesis, and ferrochelatase, the enzyme that catalyzes heme synthesis (Ponka et al. 1999, Aijoka et al. 2006). The porphyrias are disorders that arise from defects in the enzymes of heme biosynthesis. Defective pathway enzymes after ALA synthase result in accumulated substrates which can cause either skin problems, neurological complications, or both due to their toxicity in higher concentrations. They are broadly classified as hepatic porphyrias or erythropoietic porphyrias, based on the site of the overproduction of the substrate. Each defect is described together with the reaction it affects (Peoc'h et al. 2016)."
BMGC_PW0129,BMG_PW0230,"The phosphatidylinositol 3-kinase-Akt signaling pathway, involving PI3K class I enzymes, particularly class IA, controls various processes such as cell growth, proliferation and survival. Class IA enzymes couple to receptor tyrosine kinases or their adaptors; class IB couple to G-protein-coupled receptors mainly via Galphai. Members of the Akt family of protein kinases are activated downstream of class I PI3Ks and collectively (Akt1, 2, and 3) phosphorylate more than 70 cytoplasmic and nuclear substrates. Deregulation of the pathway has been linked to various forms of cancer. [KEGG:04151, PID:200197, PMID:14737178, PMID:15023437, PMID:15143962, Reactome:R-HSA-109704]","The phosphatidylinositol 3' -kinase(PI3K)-Akt signaling pathway is activated by many types of cellular stimuli or toxic insults and regulates fundamental cellular functions such as transcription, translation, proliferation, growth, and survival. The binding of growth factors to their receptor tyrosine kinase (RTK) or G protein-coupled receptors (GPCR) stimulates class Ia and Ib PI3K isoforms, respectively. PI3K catalyzes the production of phosphatidylinositol-3,4,5-triphosphate (PIP3) at the cell membrane. PIP3 in turn serves as a second messenger that helps to activate Akt. Once active, Akt can control key cellular processes by phosphorylating substrates involved in apoptosis, protein synthesis, metabolism, and cell cycle.",The PI3K (Phosphatidlyinositol-3-kinase) - AKT signaling pathway stimulates cell growth and survival.
BMGC_PW0130,BMG_PW0231,"Tumor necrosis factor (Tnf) signaling plays pivotal roles in immunity, cell proliferation, differentiation and apoptosis by activating several pathways. NF-kB is a major pathway activated by Tnf; others include JNK and P38 MAPK. Through receptor-associated adapters, Tnf elicits apoptosis via the extrinsic pathway. Deregulation of Tnf signaling has been implicated in a great number of human diseases - cerebral malaria, cancer and multiple sclerosis are a few examples. [GO:0033209, PID:200102, PMID:12040173, PMID:12655295, PMID:20303867, Reactome:R-HSA-75893]","Tumor necrosis factor (TNF), as a critical cytokine, can induce a wide range of intracellular signal pathways including apoptosis and cell survival as well as inflammation and immunity. Activated TNF is assembled to a homotrimer and binds to its receptors (TNFR1, TNFR2) resulting in the trimerization of TNFR1 or TNFR2. TNFR1 is expressed by nearly all cells and is the major receptor for TNF (also called TNF-alpha). In contrast, TNFR2 is expressed in limited cells such as CD4 and CD8 T lymphocytes, endothelial cells, microglia, oligodendrocytes, neuron subtypes, cardiac myocytes, thymocytes and human mesenchymal stem cells. It is the receptor for both TNF and LTA (also called TNF-beta). Upon binding of the ligand, TNFR mediates the association of some adaptor proteins such as TRADD or TRAF2, which in turn initiate recruitment of signal transducers. TNFR1 signaling induces activation of many genes, primarily controlled by two distinct pathways, NF-kappa B pathway and the MAPK cascade, or apoptosis and necroptosis. TNFR2 signaling activates NF-kappa B pathway including PI3K-dependent NF-kappa B pathway and JNK pathway leading to survival.","The inflammatory cytokine tumor necrosis factor alpha (TNF-α) is expressed in immune and nonimmune cell types including macrophages, T cells, mast cells, granulocytes, natural killer (NK) cells, fibroblasts, neurons, keratinocytes and smooth muscle cells as a response to tissue injury or upon immune responses to pathogenic stimuli (Köck A. et al. 1990; Dubravec DB et al. 1990; Walsh LJ et al. 1991; te Velde AA et al. 1990; Imaizumi T et al. 2000). TNF-α interacts with two receptors, namely TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2). Activation of TNFR1 can trigger multiple signal transduction pathways inducing inflammation, proliferation, survival or cell death (Ward C et al. 1999; Micheau O and Tschopp J 2003; Widera D et al. 2006). Whether a TNF-α-stimulated cell will survive or die is dependent on autocrine/paracrine signals, and on the cellular context. TNF binding to TNFR1 results initially in the formation of complex I that consists of TNFR1, TRADD (TNFR1-associated death domain), TRAF2 (TNF receptor associated factor-2), RIPK1 (receptor-interacting serin/threonine protein kinase 1), and E3 ubiquitin ligases BIRC2,BIRC3 (cIAP1/2,cellular inhibitor of apoptosis) and LUBAC (Micheau O and Tschopp J 2003). The conjugation of ubiquitin chains by BIRC2/3 and LUBAC (composed of HOIP, HOIL-1 and SHARPIN ) to RIPK1 allows further recruitment and activation of the TAK1 (also known as mitogen-activated protein kinase kinase kinase 7 (MAP3K7)) complex and IκB kinase (IKK) complex. TAK1 and IKK phosphorylate RIPK1 to limit its cytotoxic activity and activate both nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NFkappaB) and mitogen‐activated protein (MAP) kinase signaling pathways promoting cell survival by induction of anti-apoptotic proteins such as BIRC, cellular FLICE (FADD-like IL-1β-converting enzyme)-like inhibitory protein (cFLIP) and secretion of pro-inflammatory cytokines (TNF and IL-6). When the survival pathway is inhibited, the TRADD:TRAF2:RIPK1 detaches from the membrane-bound TNFR1 signaling complex and recruits Fas-associated death domain-containing protein (FADD) and procaspase-8 (also known as complex II). Once recruited to FADD, multiple procaspase-8 molecules interact via their tandem death-effector domains (DED), thereby facilitating both proximity-induced dimerization and proteolytic cleavage of procaspase-8, which are required for initiation of apoptotic cell death (Hughes MA et al. 2009; Oberst A et al. 2010). When caspase activity is inhibited under certain pathophysiological conditions (e.g., expression of caspase-8 inhibitory proteins such as CrmA and vICA after infection with cowpox virus or CMV) or by pharmacological agents, deubiquitinated RIPK1 is physically and functionally engaged by its homolog RIPK3 leading to formation of the necrosome, a necroptosis-inducing complex consisting of RIPK1 and RIPK3 (Tewari M & Dixit VM 1995; Fliss PM & Brune W 2012; Sawai H 2013; Moquin DM et al. 2013; Kalai M et al. 2002; Cho YS et al. 2009, He S et al. 2009, Zhang DW et al., 2009). Within the complex II procaspase-8 can also form heterodimers with cFLIP isoforms, FLIP long (L) and FLIP short (S), which are encoded by the NFkappaB target gene CFLAR (Irmler M et al. 1997; Boatright KM et al. 2004; Yu JW et al. 2009; Pop C et al. 2011). FLIP(S) appears to act purely as an antagonist of caspase-8 activity blocking apoptotic but promoting necroptotic cell death (Feoktistova et al. 2011). The regulatory function of FLIP(L) has been found to differ depending on its expression levels. FLIP(L) was shown to inhibit death receptor (DR)-mediated apoptosis only when expressed at high levels, while low cell levels of FLIP(L) enhanced DR signaling to apoptosis (Boatright KM et al. 2004; Okano H et al. 2003; Yerbes R et al. 2011; Yu JW et al. 2009; Hughes MA et al. 2016). In addition, caspase-8:FLIP(L) heterodimer activity within the TRADD:TRAF2:RIPK1:FADD:CASP8:FLIP(L) complex allowed cleavage of RIPK1 to cause the dissociation of the TRADD:TRAF2:RIP1:FADD:CASP8, thereby inhibiting RIPK1-mediated necroptosis (Feoktistova et al. 2011, 2012). TNF-α can also activate sphingomyelinase (SMASE, such as SMPD2,3) proteins to catalyze hydrolysis of sphingomyeline into ceramide (Adam D et al.1996; Adam-Klages S et al. 1998; Ségui B et al. 2001). Activation of neutral SMPD2,3 leads to an accumulation of ceramide at the cell surface and has proinflammatory effects. However, TNF can also activate the pro-apoptotic acidic SMASE via caspase-8 mediated activation of caspase-7 which in turn proteolytically cleaves and activates the 72kDa pro-A-SMase form (Edelmann B et al. 2011). Ceramide induces anti-proliferative and pro-apoptotic responses. Further, ceramide can be converted by ceramidase into sphingosine, which in turn is phosphorylated by sphingosine kinase into sphingosine-1-phosphate (S1P). S1P exerts the opposite biological effects to ceramide by activating cytoprotective signaling to promote cell growth counteracting the apoptotic stimuli (Cuvillier O et al. 1996). Thus, TNF-α-induced TNFR1 activation leads to divergent intracellular signaling networks with extensive cross-talk between the pro-apoptotic/necroptotic pathway, and the other NFkappaB, and MAPK pathways providing highly specific cell responses initiated by various types of stimuli."
BMGC_PW0131,BMG_PW0232,"The innate immune response - a universal and ancient form of host defense against infection - is a first line of response to various pathogens and also to damaged cells. It plays a role in stimulating adaptive immunity; molecules generated during innate responses act as second signals that can impact on both the magnitude and the nature of the adaptive response. [GO:0045087, PMID:11861602, PMID:20303867, Reactome:R-HSA-168249]",,Innate immunity encompases the nonspecific part of immunity tha are part of an individual's natural biologic makeup
BMGC_PW0132,BMG_PW0233,"The adaptive immune response is an evolutionarily newer mechanism that provides great specificity and diversity of antigen recognition, immunological memory and specialized responses. The two types of adaptive immune response pathways are humoral and cellular or cell-mediated. [GO:0002250, MCW_library:Handbook_on_cellular_and_molecular_immunology, PMID:11861602, Reactome:R-HSA-1280218]",,"Adaptive immunity refers to antigen-specific immune response efficiently involved in clearing the pathogens. The adaptive immune system is comprised of B and T lymphocytes that express receptors with remarkable diversity tailored to recognize aspects of particular pathogens or antigens. During infection, dendritic cells (DC) which act as sentinels in the peripheral tissues recognize and pick up the pathogen in the form of antigenic determinants and then process these antigens and present them to T cells. These T cells of appropriate specificity respond to the antigen, and either kill the pathogen directly or secrete cytokines that will stimulate B lymphocyte response. B cells provide humoral immunity by secreting antibodies specific for the pathogen or antigen."
BMGC_PW0133,BMG_PW0237,"Diabetes mellitus is characterized by abnormally high levels of glucose in the blood. Hereditary and environmental factors are likely contributors but the exact mechanisms are not well understood. The type 1 diabetes mellitus pathway involves alterations in immune response pathways resulting in destruction of the insulin-producing beta cells. [KEGG:map04940, OneLook:www.onelook.com]","Type I diabetes mellitus is a disease that results from autoimmune destruction of the insulin-producing beta-cells. Certain beta-cell proteins act as autoantigens after being processed by antigen-presenting cell (APC), such as macrophages and dendritic cells, and presented in a complex with MHC-II molecules on the surface of the APC. Then immunogenic signals from APC activate CD4+ T cells, predominantly of the Th1 subset. Antigen-activated Th1 cells produce IL-2 and IFNgamma. They activate macrophages and cytotoxic CD8+ T cells, and these effector cells may kill islet beta-cells by one or both of two types of mechanisms: (1) direct interactions of antigen-specific cytotoxic T cells with a beta-cell autoantigen-MHC-I complex on the beta-cell, and (2) non-specific inflammatory mediators, such as free radicals/oxidants and cytokines (IL-1, TNFalpha, TNFbeta, IFNgamma).             Type I diabetes is a polygenic disease. One of the principle determining genetic factors in diabetes incidence is the inheritance of mutant MHC-II alleles. Another plausible candidate gene is the insulin gene.",
BMGC_PW0134,BMG_PW0241,"The VEGF family plays key roles in angiogenesis and lymphangiogenesis. Through their receptors, VEGFs can initiate a diverse and complex network of signaling cascades. Deregulation of VEGF-mediated pathways, mostly through upregulation of VEGF expression, has been implicated in a number of conditions, primarily cancer. [GO:0048010, KEGG:map04370, OneLook:www.onelook.com, PID:200109, PID:200188, PMID:15544039, PMID:15563310, Reactome:R-HSA-194138]","There is now much evidence that VEGFR-2 is the major mediator of VEGF-driven responses in endothelial cells and it is considered to be a crucial signal transducer in both physiologic and pathologic angiogenesis. The binding of VEGF to VEGFR-2 leads to a cascade of different signaling pathways, resulting in the up-regulation of genes involved in mediating the proliferation and migration of endothelial cells and promoting their survival and vascular permeability. For example, the binding of VEGF to VEGFR-2 leads to dimerization of the receptor, followed by intracellular activation of the PLCgamma;PKC-Raf kinase-MEK-mitogen-activated protein kinase (MAPK) pathway and subsequent initiation of DNA synthesis and cell growth, whereas activation of the phosphatidylinositol 3' -kinase (PI3K)-Akt pathway leads to increased endothelial-cell survival. Activation of PI3K, FAK, and p38 MAPK is implicated in cell migration signaling.","In normal development vascular endothelial growth factors (VEGFs) are crucial regulators of vascular development during embryogenesis (vasculogenesis) and blood-vessel formation in the adult (angiogenesis). In tumor progression, activation of VEGF pathways promotes tumor vascularization, facilitating tumor growth and metastasis. Abnormal VEGF function is also associated with inflammatory diseases including atherosclerosis, and hyperthyroidism. The members of the VEGF and VEGF-receptor protein families have distinct but overlapping ligand-receptor specificities, cell-type expression, and function. VEGF-receptor activation in turn regulates a network of signaling processes in the body that promote endothelial cell growth, migration and survival (Hicklin and Ellis, 2005; Shibuya and Claesson-Welsh, 2006). Molecular features of the VGF signaling cascades are outlined in the figure below (from Olsson et al. 2006; Nature Publishing Group). Tyrosine residues in the intracellular domains of VEGF receptors 1, 2,and 3 are indicated by dark blue boxes; residues susceptible to phosphorylation are numbered. A circled R indicates that phosphorylation is regulated by cell state (VEGFR2), by ligand binding (VEGFR1), or by heterodimerization (VEGFR3). Specific phosphorylation sites (boxed numbers) bind signaling molecules (dark blue ovals), whose interaction with other cytosolic signaling molecules (light blue ovals) leads to specific cellular (pale blue boxes) and tissue-level (pink boxes) responses in vivo. Signaling cascades whose molecular details are unclear are indicated by dashed arrows. DAG, diacylglycerol; EC, endothelial cell; eNOS, endothelial nitric oxide synthase; FAK, focal adhesion kinase; HPC, hematopoietic progenitor cell; HSP27, heat-shock protein-27; MAPK, mitogen-activated protein kinase; MEK, MAPK and ERK kinase; PI3K, phosphatidylinositol 3' kinase; PKC, protein kinase C; PLCgamma, phospholipase C-gamma; Shb, SH2 and beta-cells; TSAd, T-cell-specific adaptor. In the current release, the first events in these cascades - the interactions between VEGF proteins and their receptors - are annotated."
BMGC_PW0135,BMG_PW0247,"Those metabolic reactions involved in the biosynthesis of lipopolysaccharides, also known as lipoglycans, found in the outer membranes of Gram-negative bacteria. They are large molecules consisting of a lipid and a polysaccharide joined by a covalent bond. In host cells they act as endotoxins which are recognized by members of the Toll-like receptors to elicit strong immune responses. [GO:0009103, KEGG:map00540, OneLook:www.onelook.com]",,
BMGC_PW0136,BMG_PW0248,"Those metabolic reactions involved in the biosynthesis of peptidoglycan - a high molecular weight polymer that forms the tough, rigid structure of bacterial cell walls. It is made up of three parts: (1) a backbone, composed of alternating N-acetylglucosamine and N-acetylmuramic acid; (2) a set of identical tetrapeptide side-chains attached to N-acetylmuramic acid; and (3) a set of identical peptide cross-bridges. The backbone is the same in all bacterial species; however, the tetrapeptide side-chains and the peptide cross-bridges vary from species to species. [GO:0009252, KEGG:map00550, OneLook:www.onelook.com]",,
BMGC_PW0137,BMG_PW0249,"Those metabolic reactions involved in the synthesis of diterpenoids. Terpenoids are a large class of naturally-occurring organic chemicals. They are derived from five-carbon units and are modifed in manifold ways. [GO:0016102, KEGG:map00904, OneLook:www.onelook.com]",,
BMGC_PW0138,BMG_PW0252,"Those metabolic reactions involved in the biosynthesis of penicillin and cephalosporins. The former is the best known antibiotic which blocks the cross linking reaction in peptidoglycan synthesis, thus destroying the bacterial cell wall. The latter represents a broad class of antibiotics similar to penicillin, both chemically and in mode of action. [KEGG:map00311, OneLook:www.onelook.com]",,
BMGC_PW0139,BMG_PW0256,"Those metabolic reactions involved in the synthesis of tetracyclines - any of a group of biosynthetic antibiotics. Some are isolated from certain species of Streptomyces and others are produced semisynthetically. [GO:0043644, KEGG:map00253, OneLook:www.onelook.com]",,
BMGC_PW0140,BMG_PW0257,"Those metabolic reactions involved in the biosynthesis of clavulanic acid. Clavulanic acid is a beta-lactam antibiotic produced by a bacterium of the genus Streptomyces (S. clavuligerus) that is a beta-lactamase inhibitor and is usually used in the form of its clavulanate salt of potassium especially in combination with amoxicillin. [GO:0033050, Internet:Google, KEGG:map00331]",,
BMGC_PW0141,BMG_PW0267,"Those reactions and molecular interactions underlying the folding of a protein into its functional three-dimensional structure. Folding takes place in the cytoplasm and, in the case of secreted proteins, in the endoplasmic reticulum. Proteins are checked (quality control) for proper folding and misfolded proteins are targeted for degradation. [GO:0006457, PMID:17686625, PMID:21495850, Reactome:R-HSA-391251]",,"Due to the crowded envirnoment within the cell, many proteins must interact with molecular chaperones to attain their native conformation (reviewed in Young et al., 2004). Chaperones recognize and associate with proteins in their non-native state and facilitate their folding by stabilizing the conformation of productive folding intermediates. Chaperones that take part broadly in de novo protein folding, such as the Hsp70s and the chaperonins, facilitate the folding process through cycles of substrate binding and release regulated by their ATPase activity (see Young et al., 2004; Spiess et al., 2004; Bigotti and Clarke, 2008)."
BMGC_PW0142,BMG_PW0272,"A neurotransmitter-releasing pathway of neuron-to-neuron communication. It involves fusion of neurotransmitter-filled synaptic vesicles with the plasma membrane and activation of postsynaptic receptors. It also involves recycling and re-release of synaptic vesicles. [GO:0007268, PubMed:Annu._Rev._Neursci._2003\,_v26\,_701-28., Reactome:R-HSA-112315]",,"Chemical synapses are specialized junctions that are used for communication between neurons, neurons and muscle or gland cells. The synapse involves a presynaptic neuron and a postsynaptic neuron, muscle cell or glad cell. The pre and the postsynaptic cell are separated by a gap (space) of 20 to 40 nm called the synaptic cleft. The signals pass in a single direction from the presynaptic to postsynaptic neuron (cell). The presynaptic neuron communicates via the release of neurotransmitter which bind the receptors on the postsynaptic cell. The process is initiated when an action potential invades the terminal membrane of the presynaptic neuron. Action potentials occur in electrically excitable cells such as neurons and muscles and endocrine cells. They are initiated by the transient opening of voltage dependent sodium channels, causing a rapid, large depolarization of membrane potentials that spread along the axon membrane. When action potentials arrive at the synaptic terminals, depolarization in membrane potential leads to the opening of voltage gated calcium channels located on the presynaptic membrane. The external Ca2+ concentration is approximately 10-3 M while the internal Ca2+ concentration is approximately 10-7 M. Opening of calcium channels causes a rapid influx of Ca2+ into the presynaptic terminal. The elevated presynaptic Ca2+ concentration allows synaptic vesicles to fuse with the plasma membrane of the presynaptic neuron and release their contents, neurotransmitters, into the synaptic cleft. These diffuse across the synaptic cleft and bind to specific receptors on the membrane of the postsynaptic cells. Activation of postsynaptic receptors upon neurotransmitter binding can lead to a multitude of effects in the postsynaptic cell, such as changing the membrane potential and excitability, and triggering intracellular signaling cascades."
BMGC_PW0143,BMG_PW0275,"Cellular senescence, also known as replicative senescence, results from cells ceasing to divide. Generally, it is a state of steady cell cycle arrest induced by stresses such as DNA damage, toxins and/or oncogene activation. [GO:0090398, PMID:24449267, Reactome:R-HSA-2559583]","Cellular senescence is a state of irreversible cellular arrest and can be triggered by a number of factors, such as telomere shortening, oncogene activation, irradiation, DNA damage and oxidative stress. It is characterized by enlarged flattened morphology, senescence-associated beta-galactosidase (SA-b-gal) activity, secretion of inflammatory cytokines, growth factors and matrix metalloproteinases, as part of the senescence-associated secretory phenotype (SASP). Cellular senescence is functionally associated with many biological processes including aging, tumor suppression, placental biology, embryonic development, and wound healing.","Cellular senescence involves irreversible growth arrest accompanied by phenotypic changes such as enlarged morphology, reorganization of chromatin through formation of senescence-associated heterochromatic foci (SAHF), and changes in gene expression that result in secretion of a number of proteins that alter local tissue environment, known as senescence-associated secretory phenotype (SASP). Senescence is considered to be a cancer protective mechanism and is also involved in aging. Senescent cells accumulate in aged tissues (reviewed by Campisi 1997 and Lopez-Otin 2013), which may be due to an increased senescence rate and/or decrease in the rate of clearance of senescent cells. In a mouse model of accelerated aging, clearance of senescent cells delays the onset of age-related phenotypes (Baker et al. 2011). Cellular senescence can be triggered by the aberrant activation of oncogenes or loss-of-function of tumor suppressor genes, and this type of senescence is known as the oncogene-induced senescence, with RAS signaling-induced senescence being the best studied. Oxidative stress, which may or may not be caused by oncogenic RAS signaling, can also trigger senescence. Finally, the cellular senescence program can be initiated by DNA damage, which may be caused by reactive oxygen species (ROS) during oxidative stress, and by telomere shortening caused by replicative exhaustion which may be due to oncogenic signaling. The senescent phenotype was first reported by Hayflick and Moorhead in 1961, when they proposed replicative senescence as a mechanism responsible for the cessation of mitotic activity and morphological changes that occur in human somatic diploid cell strains as a consequence of serial passaging, preventing the continuous culture of untransformed cells-the Hayflick limit (Hayflick and Moorhead 1961). Secreted proteins that constitute the senescence-associated secretory phenotype (SASP), also known as the senescence messaging secretome (SMS), include inflammatory and immune-modulatory cytokines, growth factors, shed cell surface molecules and survival factors. The SASP profile is not significantly affected by the type of senescence trigger or the cell type (Coppe et al. 2008), but the persistent DNA damage may be a deciding SASP initiator (Rodier et al. 2009). SASP components function in an autocrine manner, reinforcing the senescent phenotype (Kuilman et al. 2008, Acosta et al. 2008), and in the paracrine manner, where they may promote epithelial-to-mesenchymal transition (EMT) and malignancy in the nearby premalignant or malignant cells (Coppe et al. 2008). Senescent cells may remain viable for years, such as senescent melanocytes of moles and nevi, or they can be removed by phagocytic cells. The standard marker for immunohistochemical detection of senescent cells is senescence-associated beta-galactosidase (SA-beta-Gal), a lysosomal enzyme that is not required for senescence. For reviews of this topic, please refer to Collado et al. 2007, Adams 2009, Kuilman et al. 2010. For a review of differential gene expression between senescent and immortalized cells, please refer to Fridman and Tainsky 2008."
BMGC_PW0144,BMG_PW0276,"The autophagic pathway involves the sequestration of misfolded or long-lived proteins and of defective organelles within double membrane vesicles, and delivery of the cargo to lysosomes for degradation and recycling. It is also known as macroautophagy, or bulk autophagy. [GO:0016236, https://en.wikipedia.org/wiki/Autophagy wikipedia, KEGG:04140, PMID:20034776, PMID:20089931, PMID:20211164, Reactome:R-HSA-1632852]","Autophagy (or macroautophagy) is a cellular catabolic pathway involving in protein degradation, organelle turnover, and non-selective breakdown of cytoplasmic components, which is evolutionarily conserved among eukaryotes and exquisitely regulated. This progress initiates with production of the autophagosome, a double-membrane intracellular structure of reticular origin that engulfs cytoplasmic contents and ultimately fuses with lysosomes for cargo degradation. Autophagy is regulated in response to extra- or intracellular stress and signals such as starvation, growth factor deprivation and ER stress. Constitutive level of autophagy plays an important role in cellular homeostasis and maintains quality control of essential cellular components.","Macroautophagy (hereafter referred to as autophagy) acts as a buffer against starvation by liberating building materials and energy sources from cellular components. It has additional roles in embryonic development, removal of apoptotic cells or organelles, antigen presentation, protection against toxins and as a degradation route for aggregate-prone proteins and infectious agents. The dysregulation of autophagy is involved in several human diseases, for example, Crohn's disease, cancer and neurodegeneration (Ravikumar et al. 2010). Autophagy is highly conserved from yeast to humans; much of the machinery was first identified in yeast (see Klionsky et al. 2011). Initially, double-membraned cup-shaped structures called the isolation membrane or phagophore engulf portions of cytoplasm. The membranes fuse to form the autophagosome. In yeast cells, autophagosomes are formed at the phagophore assembly site (PAS) next to the vacuole. In mammals, autophagosomes appear throughout the cytoplasm then move along microtubules towards the microtubule-organising centre. This transport requires microtubules and the function of dynein motor proteins; depolymerization of microtubules or inhibition of dynein-dependent transport results in inhibition of autophagy (Kochl et al. 2006, Kimura et al. 2008). Autophagosomes fuse with lysosomes forming autolysosomes whose contents are degraded by lysosomal hydrolases (Mizushima et al. 2011). The origins of the autophagosomal membrane and the incorporation of existing membrane material have been extensively debated. The endoplasmic reticulum (ER), mitochondria, mitochondria-associated ER membranes (MAMs), the Golgi, the plasma membrane and recycling endosomes have all been implicated in the nucleation of the isolation membrane and subsequent growth of the membrane (Lamb et al. 2013). Recently 3D tomographic imaging of isolation membranes has shown the cup-shaped isolation membrane tightly sandwiched between two sheets of ER and physically connected to the ER through a narrow membrane tube (Hayashi-Nishino et al. 2009, Yla-Anttila et al. 2009). This suggests that isolation membrane formation and elongation are guided by adjacent ER sheets, supporting the now prevalent 'ER cradle' model, which suggests that the isolation membrane arises from the ER (Hayashi-Nishino et al. 2009, Shibutani & Yoshimori 2014). Autophagy is tightly regulated. The induction of autophagy in response to starvation is partly mediated by inactivation of the mammalian target of rapamycin (mTOR) (Noda & Ohsumi 1998) and activation of Jun N-terminal kinase (JNK), while energy loss induces autophagy by activation of AMP kinase (AMPK). Other pathways regulating autophagy are regulated by calcium, cyclic AMP, calpains and the inositol trisphosphate (IP3) receptor (Rubinsztein et al. 2012). In mammals, two complexes cooperatively produce the isolation membrane. The ULK complex consists of ULK1/2, ATG13, (FIP200) and ATG101 (Alers et al. 2012). The PIK3C3-containing Beclin-1 complex consists of PIK3C3 (Vps34), BECN1 (Beclin-1, Atg6), PIK3R4 (p150, Vps15) and ATG14 (Barkor) (Matsunaga et al. 2009, Zhong et al. 2009). A similar complex where ATG14 is replaced by UVRAG functions later in autophagosome maturation and endocytic traffic (Itakura et al. 2008, Liang et al. 2008). Binding of KIAA0226 to this complex negatively regulates the maturation process (Matsunaga et al. 2009). The ULK and Beclin-1 complexes are recruited to specific autophagosome nucleation regions where they stimulate phosphatidylinositol-3-phosphate (PI3P) production and facilitate the elongation and initial membrane curvature of the phagophore membrane (Carlsson & Simonsen 2015). The ULK complex is considered the most upstream component of the mammalian autophagy pathway (Itakura & Mizushima 2010), acting as an integrator of the autophagy signals downstream of mTORC1. It is not fully understood how ULK1 is modulated in response to environmental cues. Phosphorylation plays an essential role (Dunlop & Tee 2013) but it is not clear how phosphorylation regulates ULK1 activities (Ravikumar et al. 2010). ULK1 kinase activity is required for autophagy, but the substrate(s) of ULK1 that mediate its autophagic function are not certain. ULK1 may also have kinase-independent functions in autophagy (Wong et al. 2013). PIK3C3 (Vps34) is a class III phosphatidylinositol 3-kinase that produces PI3P. It is essential for the early stages of autophagy and colocalizes strongly with early autophagosome markers (Axe et al. 2008). BECN1 binds several further proteins that affect autophagosome formation. Partners that induce autophagy include AMBRA1 (Fimia et al. 2007), UVRAG (Liang et al. 2006) and SH3GLB1 (Takahashi et al. 2007). Binding of BCL2 or BCL2L1 (Bcl-xL) inhibit autophagy (Pattingre et al. 2005, Ciechomska et al. 2009). The inositol 1,4,5-trisphosphate receptor complex that binds BCL2 also interacts with BECN1, inhibiting autophagy (Vincencio et al. 2009). CISD2 (Nutrient-deprivation autophagy factor-1, NAF1), a component in the IP3R complex, interacts with BCL2 at the ER and stabilizes the BCL2-BECN1 interaction (Chang et al. 2010). Starvation leads to activation of c-Jun NH2-terminal kinase-1 (JNK1), which results in the phosphorylation of BCL2 and BCL2L1, which release their binding to BECN1 and thus induces autophagosome formation (Wei et al. 2008). AMBRA1 can simultaneously bind dynein and the Beclin-1 complex. During nutrient starvation, AMBRA1 is phosphorylated in a ULK1-dependent manner (Di Bartolomeo et al. 2010). This phosphorylation releases AMBRA1-associated Beclin-1 complexes from dynein and the microtubule network, freeing the complex to translocate to autophagy initiation sites (Di Bartolomeo et al. 2010). A characteristic of this early phase of autophagosome formation is the formation of PI3P-enriched ER-associated structures called omegasomes (Axe et al. 2008) or cradles (Hayashi-Nishino et al. 2009). Omegasomes appear to concentrate at or near the connected mitochondria-associated ER membrane (Hamasaki et al. 2013). However, the phagophore also can incorporate existing material from other membrane sources such as ER exit sites (ERES), the ER-Golgi intermediate compartment (ERGIC), the Golgi, the plasma membrane and recycling endosomes (Carlsson & Simonsen 2015). Omegasomes lead to the formation of the isolation membrane or phagophore, which is thought to form de novo by an unknown mechanism (Simonsen & Stenmark 2008, Roberts & Ktistakis 2013). Phagophore expansion is probably mediated by membrane uptake from endomembranes and semi-autonomous organelles (Lamb et al. 2013, Shibutani & Yoshimori 2014). ATG9 is a direct target of ULK1. In nutrient-rich conditions mammalian ATG9 is localized to the trans-Golgi network and endosomes (including early, late and recycling endosomes), whereas under starvation conditions it is localized to autophagosomes, in a process that is dependent on ULK1 (Young et al. 2006). ATG9 is believed to play a role in the delivery of vesicles derived from existing membranes to the expanding phagophore (Lamb et al. 2013). Yeast Atg9 forms a complex with Atg2 and Atg18 (Reggiori et al. 2004). PI3P produced at the initiation site is sensed by WIPI2b, the mammalian homologue of Atg18 (Polson et al. 2010). WIPI2b then recruits Atg16L1 (Dooley et al. 2014). There are four WIPI proteins in mammalian cells (Proikas-Cezanne et al. 2015). They are all likely bind PI3P and be recruited to membranes but the function of WIPI1, 3 and 4 in autophagy is not yet clear. WIPI4 (WDR45) has been shown to bind Atg2 and to be involved in lipid droplet formation (Velikkakath et al. 2012); mutations in WIPI4 have been shown to cause a neurodegenerative disease (Saitsu et al. 2013). The elongation of the membrane that will become the autophagosome is regulated by two ubiquitination-like reactions. First, the ubiquitin-like molecule ATG12 is conjugated to ATG5 by ATG7, which acts as an E1-like activating enzyme, and ATG10, which has a role similar to an E2 ubiquitin-conjugating enzyme. The ATG5:ATG12 complex then interacts non-covalently with ATG16L1. This complex associates with the forming autophagosome but dissociates from completed autophagosomes (Geng & Klionski 2008). The second ubiquitin-like reaction involves the conjugation of ubiquitin-like molecules of the LC3 family (Weidberg et al. 2010). LC3 proteins are conjugated through their C-terminal glycine residues with PE by the E1-like ATG7 and E2-like ATG3. This allows LC3 proteins to associate with the autophagosome membrane. The ATG12:ATG5:ATG16L1 complex (Mizushima et al., 2011) acts as an E3 like enzyme for the conjugation of LC3 family proteins (mammalian homologues of yeast Atg8) to phosphatidylethanolamine (PE) (Hanada et al. 2007, Fujita et al. 2008). LC3 PE can be deconjugated by the protease ATG4 (Li et al. 2011, 2012). ATG4 is also responsible for priming LC3 proteins by cleaving the C terminus to expose a glycine residue (Kirisako et al, 2000, Scherz Shouval et al. 2007). LC3 proteins remain associated with autophagosomes until they fuse with lysosomes. The LC3-like proteins inside the resulting autolysosomes are degraded, while those on the cytoplasmic surface are delipidated and recycled. ATG5:ATG12:ATG16L1-positive LC3-negative vesicles represent pre-autophagosomal structures (pre-phagophores and possibly early phagophores), ATG5:ATG12:ATG16L1-positive LC3-positive structures can be considered to be phagophores, and ATG5:ATG12:ATG16L1-negative LC3-positive vesicles can be regarded as mature autophagosomes (Tandia et al. 2011). Phagophore expansion is probably mediated by membrane uptake from endomembranes as well as from semiautonomous organelles (Lamb et al. 2013, Shibutani & Yoshimori 2014). The mechanisms involved in the closure of the phagophore membrane are poorly understood. As the phagophore is a double-membraned structure, its closure involves the fusion of a narrow opening, a process that is distinct from other membrane fusion events (Carlsson & Simonsen 2015). The topology of the phagophore is similar to that of cytokinesis, viral budding or multivesicular body (MVB) formation. These processes rely on the Endosomal Sorting Complex Required for Transport (ESCRT) (Rusten et al. 2012). ESCRT and associated proteins facilitate membrane budding away from the cytosol and subsequent cleavage of the bud neck (Hurley & Hanson 2010). Several studies have shown that depletion of ESCRT subunits or the regulatory ATPase Vps4 causes an accumulation of autophagosomes (Filimonenko et al. 2007, Rusten et al. 2007) but it is not clear whether ESCRTs are required for autophagosome closure or for autophagosome to endosome fusion. UVRAG is also involved in the maturation step, recruiting proteins that bring about membrane fusion such as the class C Vps proteins, which activate Rab7 thereby promoting fusion with late endosomes and lysosomes (Liang et al. 2008)."
BMGC_PW0145,BMG_PW0279,"The endocytic pathway allows for recycling of cargo delivered via the exocytic or secretory routes, uptake of nutrients, internalization of receptors and also, the engulfing of dying cells or of material foreign to the cell. Endocytosis can be subdivided into four pathways: clathrin-mediated and caveolae-mediated endocytosis, micropinocytosis and phagocytosis. Endosomes and lysosomes are central endocytic components responsible for sorting, recycling, or degradation of cargo, as necessary. [GO:0006897, KEGG:04144, PMID:16882731, PMID:16985500, PMID:18354421]","Endocytosis is a mechanism for cells to remove ligands, nutrients, and plasma membrane (PM) proteins, and lipids from the cell surface, bringing them into the cell interior. Transmembrane proteins entering through clathrin-dependent endocytosis (CDE) have sequences in their cytoplasmic domains that bind to the APs (adaptor-related protein complexes) and enable their rapid removal from the PM. In addition to APs and clathrin, there are numerous accessory proteins including dynamin. Depending on the various proteins that enter the endosome membrane, these cargoes are sorted to distinct destinations. Some cargoes, such as nutrient receptors, are recycled back to the PM. Ubiquitylated membrane proteins, such as activated growth-factor receptors, are sorted into intraluminal vesicles and eventually end up in the lysosome lumen via multivesicular endosomes (MVEs). There are distinct mechanisms of clathrin-independent endocytosis (CIE) depending upon the cargo and the cell type.",
BMGC_PW0146,BMG_PW0284,"Integrins signal bi-directionally across the plasma membrane and provide an example of mechanotransduction. Inside-out signaling modulates their interaction with ligands to regulate cell adhesion and ECM organization. Ligand binding initiates and shapes many signaling events and links to the cytoskeleton. Via protein clustering and ECM organization integrins synergize with and/or modulate various growth factor pathways. Integrin signaling regulates multiple processes including gene expression, cell proliferation, differentiation and survival. [GO:0007229, KEGG:map04510, PMID:11842240, PMID:14570568, PMID:15009204, PMID:15276463, Reactome:R-HSA-9006921]","Cell-matrix adhesions play essential roles in important biological processes including cell motility, cell proliferation, cell differentiation, regulation of gene expression and cell survival. At the cell-extracellular matrix contact points, specialized structures are formed and termed focal adhesions, where bundles of actin filaments are anchored to transmembrane receptors of the integrin family through a multi-molecular complex of junctional plaque proteins. Some of the constituents of focal adhesions participate in the structural link between membrane receptors and the actin cytoskeleton, while others are signalling molecules, including different protein kinases and phosphatases, their substrates, and various adapter proteins. Integrin signaling is dependent upon the non-receptor tyrosine kinase activities of the FAK and src proteins as well as the adaptor protein functions of FAK, src and Shc to initiate downstream signaling events. These signalling events culminate in reorganization of the actin cytoskeleton; a prerequisite for changes in cell shape and motility, and gene expression. Similar morphological alterations and modulation of gene expression are initiated by the binding of growth factors to their respective receptors, emphasizing the considerable crosstalk between adhesion- and growth factor-mediated signalling.",
BMGC_PW0147,BMG_PW0293,"Hypertrophic cardiomyopathy, or HCM, is a disease of the myocardium (the muscle of the heart) in which a portion of the myocardium is thickened. Many physiological and pathological conditions as well as many pathways underlie the hypertrophic response. [KEGG:map05410, OneLook:www.onelook.org, PMID:15276462]","Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder with an autosomal dominant pattern of inheritance that is characterized by hypertrophy of the left ventricles with histological features of myocyte hypertrophy, myfibrillar disarray, and interstitial fibrosis. HCM is one of the most common inherited cardiac disorders, with a prevalence in young adults of 1 in 500. Hundreds of mutations in the genes that encode protein constituents of the sarcomere have been identified in HCM. These mutations increase the Ca2+ sensitivity of cardiac myofilaments. Increased myofilament Ca2+ sensitivity is expected to increase the ATP utilization by actomyosin at submaximal Ca2+ concentrations, which might cause an imbalance in energy supply and demand in the heart under severe stress. The inefficient use of ATP suggests that an inability to maintain normal ATP levels could be the central abnormality. This theory might be supported by the discovery of the role of a mutant PRKAG2 gene in HCM, which in active form acts as a central sensing mechanism protecting cells from depletion of ATP supplies. The increase in the myfilament Ca2+ sensitivity well account for the diastolic dysfunction of model animals as well as human patients of HCM. It has been widely proposed that left ventricular hypertrophy is not a primary manifestation but develops as compensatory response to sarcomere dysfunction.",
BMGC_PW0148,BMG_PW0294,"The PDGF signaling pathway plays an important role in the regulation of cell growth and survival. [GO:0048008, PID:200149, PID:200162, PID:200201, PMID:14515146, PMID:26153649, Reactome:R-HSA-186797]",,"Platelet-derived Growth Factor (PDGF) is a potent stimulator of growth and motility of connective tissue cells such as fibroblasts and smooth muscle cells as well as other cells such as capillary endothelial cells and neurons.The PDGF family of growth factors is composed of four different polypeptide chains encoded by four different genes. The classical PDGF chains, PDGF-A and PDGF-B, and more recently discovered PDGF-C and PDGF-D. The four PDGF chains assemble into disulphide-bonded dimers via homo- or heterodimerization, and five different dimeric isoforms have been described so far; PDGF-AA, PDGF-AB, PDGF-BB, PDGF-CC and PDGF-DD. It is notable that no heterodimers involving PDGF-C and PDGF-D chains have been described. PDGF exerts its effects by binding to, and activating, two protein tyrosine kinase (PTK) receptors, alpha and beta. These receptors dimerize and undergo autophosphorylation. The phosphorylation sites then attract downstream effectors to transduct the signal into the cell."
BMGC_PW0149,BMG_PW0300,"The p53-dependent pathway of G1 arrest in response to damaged DNA. [InHouse:PW_dictionary, Reactome:R-HSA-69580]",,"The arrest at G1/S checkpoint is mediated by the action of a widely known tumor suppressor protein, p53. Loss of p53 functions, as a result of mutations in cancer prevent the G1/S checkpoint (Kuerbitz et al, 1992). P53 is rapidly induced in response to damaged DNA. A number of kinases, phosphatases, histone acetylases and ubiquitin-conjugating enzymes regulate the stability as well as transcriptional activity of p53 after DNA damage."
BMGC_PW0150,BMG_PW0310,"A stress-induced MAPK pathway that regulates an array of processes such as gene expression, cell migration, cytoskeletal organization and apoptosis. [GO:0007254, KEGG:map04010, PMID:15102441]","The mitogen-activated protein kinase (MAPK) cascade is a highly conserved module that is involved in various cellular functions, including cell proliferation, differentiation and migration. Mammals express at least four distinctly regulated groups of MAPKs, extracellular signal-related kinases (ERK)-1/2, Jun amino-terminal kinases (JNK1/2/3), p38 proteins (p38alpha/beta/gamma/delta) and ERK5, that are activated by specific MAPKKs: MEK1/2 for ERK1/2, MKK3/6 for the p38, MKK4/7 (JNKK1/2) for the JNKs, and MEK5 for ERK5. Each MAPKK, however, can be activated by more than one MAPKKK, increasing the complexity and diversity of MAPK signalling. Presumably each MAPKKK confers responsiveness to distinct stimuli. For example, activation of ERK1/2 by growth factors depends on the MAPKKK c-Raf, but other MAPKKKs may activate ERK1/2 in response to pro-inflammatory stimuli.","The mitogen activated protein kinases (MAPKs) are a family of conserved protein serine threonine kinases that respond to varied extracellular stimuli to activate intracellular processes including gene expression, metabolism, proliferation, differentiation and apoptosis, among others. The classic MAPK cascades, including the ERK1/2 pathway, the p38 MAPK pathway, the JNK pathway and the ERK5 pathway are characterized by three tiers of sequentially acting, activating kinases (reviewed in Kryiakis and Avruch, 2012; Cargnello and Roux, 2011). The MAPK kinase kinase kinase (MAPKKK), at the top of the cascade, is phosphorylated on serine and threonine residues in response to external stimuli; this phosphorylation often occurs in the context of an interaction between the MAPKKK protein and a member of the RAS/RHO family of small GTP-binding proteins. Activated MAPKKK proteins in turn phosphorylate the dual-specificity MAPK kinase proteins (MAPKK), which ultimately phosphorylate the MAPK proteins in a conserved Thr-X-Tyr motif in the activation loop. Less is known about the activation of the atypical families of MAPKs, which include the ERK3/4 signaling cascade, the ERK7 cascade and the NLK cascade. Although the details are not fully worked out, these MAPK proteins don't appear to be phosphorylated downstream of a 3-tiered kinase system as described above (reviewed in Coulombe and Meloche, 2007; Cargnello and Roux, 2011) . Both conventional and atypical MAPKs are proline-directed serine threonine kinases and, once activated, phosphorylate substrates in the consensus P-X-S/T-P site. Both cytosolic and nuclear targets of MAPK proteins have been identified and upon stimulation, a proportion of the phosphorylated MAPKs relocalize from the cytoplasm to the nucleus. In some cases, nuclear translocation may be accompanied by dimerization, although the relationship between these two events is not fully elaborated (reviewed in Kryiakis and Avruch, 2012; Cargnello and Roux, 2011; Plotnikov et al, 2010)."
BMGC_PW0151,BMG_PW0311,"Those signaling pathways that are mediated through the binding of calmodulin - a multifunctional calcium transducer - to its target effectors. [PMID:10884684, PMID:14671000, Reactome:R-HSA-111997]",,"Calmodulin (CaM) is a small acidic protein that contains four EF-hand motifs, each of which can bind a calcium ion, therefore it can bind up to four calcium ions. The protein has two approximately symmetrical domains, separated by a flexible hinge region. Calmodulin is the prototypical example of the EF-hand family of Ca2+-sensing proteins. Changes in intracellular Ca2+ concentration regulate calmodulin in three distinct ways. First, by directing its subcellular distribution. Second, by promoting association with different target proteins. Third, by directing a variety of conformational states in calmodulin that result in target-specific activation. Calmodulin binds and activates several effector protein (e.g. the CaM-dependent adenylyl cyclases, phosphodiesterases, protein kinases and the protein phosphatase calcineurin)."
BMGC_PW0152,BMG_PW0317,"Those metabolic reactions involved in the synthesis of novobiocin, an aminocoumarin antibiotic. It is also known as albamycin or cathomycin and is produced by an actinomycete of the order Actinobacteria. [GO:0043642, KEGG:map00401, OneLook:www.onelook.com]",,
BMGC_PW0153,BMG_PW0325,"The family of fibroblast growth factors (FGF) comprises 22 ligands classified into seven phylogenetic subfamilies and three groups by mode of action: the intracellular intracrine and the extracellular paracrine or canonical and endocrine or hormone-like groups. The paracrine subfamilies signal via the fibroblast growth factor receptors (FGFR), receptor tyrosine kinases (RTK). The endocrine subfamily is FGFR-dependent but the affinity towards the receptors is low and it relies on the Klotho family of transmembrane proteins. The intracrine subfamily is FGFR-independent. Overall, the pathway plays important roles during embryonic and postnatal development, neuromodulation, mineral metabolism and homeostasis. Deregulation of the pathway has been associated with neoplastic and metabolic diseases. [GO:0008543, PID:200220, PMID:19379279, PMID:19601767, PMID:20940169, PMID:22298654, Reactome:R-HSA-190236]",,"The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. These receptors are key regulators of several developmental processes in which cell fate and differentiation to various tissue lineages are determined. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. An alternative, FGF-independent, source of FGFR activation originates from the interaction with cell adhesion molecules, typically in the context of interactions on neural cell membranes and is crucial for neuronal survival and development. Upon ligand binding, receptor dimers are formed and their intrinsic tyrosine kinase is activated causing phosphorylation of multiple tyrosine residues on the receptors. These then serve as docking sites for the recruitment of SH2 (src homology-2) or PTB (phosphotyrosine binding) domains of adaptors, docking proteins or signaling enzymes. Signaling complexes are assembled and recruited to the active receptors resulting in a cascade of phosphorylation events. This leads to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape, depending on the cell type or stage of maturation."
BMGC_PW0154,BMG_PW0326,"The TGF-beta superfamily of growth factors regulates a broad spectrum of processes such as angiogenesis, embryonic development, cell differentiation, proliferation and wound healing. Binding to two types of serine/threonine receptors and activation of Smad proteins is a common theme. However, ligand-receptor interaction and the identity of the activated Smad protein(s) appear to be member-specific. [KEGG:map04350, PMID:15473857, Reactome:R-HSA-9006936]","The transforming growth factor-beta (TGF-beta) family members, which include TGF-betas, activins and bone morphogenetic proteins (BMPs), are structurally related secreted cytokines found in species ranging from worms and insects to mammals. A wide spectrum of cellular functions such as proliferation, apoptosis, differentiation and migration are regulated by TGF-beta family members. TGF-beta family member binds to the Type II receptor and recruits Type I, whereby Type II receptor phosphorylates and activates Type I. The Type I receptor, in turn, phosphorylates receptor-activated Smads ( R-Smads: Smad1, Smad2, Smad3, Smad5, and Smad8). Once phosphorylated, R-Smads associate with the co-mediator Smad, Smad4, and the heteromeric complex then translocates into the nucleus. In the nucleus, Smad complexes activate specific genes through cooperative interactions with other DNA-binding and coactivator (or co-repressor) proteins.","The human genome encodes 33 TGF-beta family members, including TGF-beta itself, as well as bone morphogenetic protein (BMP), activin, nodal and growth and differentiation factors (GDFs). This superfamily of ligands generally binds as dimers to hetero-tetrameric cell-surface receptor serine/threonine kinases to activate SMAD-dependent and SMAD-independent signaling (reviewed in Morikawa et al, 2016; Budi et al, 2017). Signaling by the TGF-beta receptor complex is initiated by TGF-beta. TGF-beta (TGFB1), secreted as a homodimer, binds to TGF-beta receptor II (TGFBR2), inducing its dimerization and formation of a stable hetero-tetrameric complex with TGF-beta receptor I homodimer (TGFBR1). TGFBR2-mediated phosphorylation of TGFBR1 triggers internalization of the heterotetrameric TGF beta receptor complex (TGFBR) into clathrin coated endocytic vesicles and recruitment of cytosolic SMAD2 and SMAD3, which act as R-SMADs for TGF beta receptor complex. TGFBR1 phosphorylates SMAD2 and SMAD3, promoting their association with SMAD4 (known as Co-SMAD). In the nucleus, the SMAD2/3:SMAD4 heterotrimer binds target DNA elements and, in cooperation with other transcription factors, regulates expression of genes involved in cell differentiation. For a review of TGF-beta receptor signaling, please refer to Kang et al. 2009. Signaling by BMP is triggered by bone morphogenetic proteins (BMPs). BMPs can bind type I receptors in the absence of type II receptors, but the presence of both types dramatically increases binding affinity. The type II receptor kinase transphosphorylates the type I receptor, leading to recruitment and phosphorylation of SMAD1, SMAD5 and SMAD8, which function as R-SMADs in BMP signalling pathways. Phosphorylated SMAD1, SMAD5 and SMAD8 form heterotrimeric complexes with SMAD4, the only Co-SMAD in mammals. The SMAD1/5/8:SMAD4 heterotrimer regulates transcription of genes involved in development of many tissues, including bone, cartilage, blood vessels, heart, kidney, neurons, liver and lung. For review of BMP signaling, please refer to Miyazono et al. 2010. Signaling by activin is triggered when an activin dimer (activin A, activin AB or activin B) binds the type II receptor (ACVR2A, ACVR2B). This complex then interacts with the type I receptor (ACVR1B, ACVR1C) and phosphorylates it. The phosphorylated type I receptor phosphorylates SMAD2 and SMAD3. Dimers of phosphorylated SMAD2/3 bind SMAD4 and the resulting ternary complex enters the nucleus and activates target genes. For a review of activin signaling, please refer to Chen et al. 2006."
BMGC_PW0155,BMG_PW0327,"The bone morphogenetic proteins (BMP) are related to TGF-beta and activins and are members of the TGF-beta superfamily. The BMP signaling pathway plays important roles in induction and patterning of the mesoderm. BMP pathway cross-talks to other pathways such as TGF-beta, Wnt, MAPK, Notch, JAK-STAT and others. [GO:0030509, PID:200144, PMID:15368350, Reactome:R-HSA-201451]",,"Bone morphogenetic proteins (BMPs) have many biological activities in various tissues, including bone, cartilage, blood vessels, heart, kidney, neurons, liver and lung. They are members of the Transforming growth factor-Beta (TGFB) family. They bind to type II and type I serine-threonine kinase receptors, which transduce signals through SMAD and non-SMAD signalling pathways. BMP signalling is linked to a wide variety of clinical disorders, including vascular diseases, skeletal diseases and cancer. BMPs typically activate BMP type I receptors and signal via SMAD1, 5 and 8. They can be classified into several subgroups, including the BMP2/4 group, the BMP5-8 osteogenic protein-1 (OP1) group, the growth and differentiation factor (GDF) 5-7 group and the BMP9/10 group. Most of the proteins of the BMP2/4, OP1 and BMP9/10 groups induce formation of bone and cartilage tissues in vivo, while the GDF5-7 group induce cartilage and tendon-like, but not bone-like, tissues (Miyazono et al. 2010). Members of the TGFB family bind to two types of serine-threonine kinase receptors, type I and type II (Massagué 2012). BMPs can bind type I receptors in the absence of type II receptors, but both types are required for signal transduction. The presence of both types dramatically increases binding affinity (Rozenweig et al. 1995). The type II receptor kinase transphosphorylates the type I receptor, which transmits specific intracellular signals. Type I and type II receptors share similar structural properties, comprised of a relatively short extracellular domain, a single membrane-spanning domain and an intracellular domain containing a serine-threonine kinase domain. Seven receptors, collectively referred to as the Activin receptor-like kinases (ALK), have been identified as type I receptors for the TGFB family in mammals. ALKs are classified into three groups based on their structure and function, the BMPRI group (Bone morphogenetic protein receptor type-1A, ALK3, BMPR1A and Bone morphogenetic protein receptor type-1B, ALK6, BMPR1B), the ALK1 group (Serine/threonine-protein kinase receptor R3, ALK1, ACVRL1 and Activin receptor type-1, ALK2, ACVR1) and the TBetaR1 group (Activin receptor type-1B, ALK4, ACVR1B and TGF-beta receptor type-1, ALK5, TGFBR1 and Activin receptor type-1C, ALK7, ACVR1C) (Kawabata et al. 1998). ALK1 group and BMPRI group activate SMAD1/5/8 and transduce similar intracellular signals. The TBetaR1 group activate SMAD2/3. BMPR1A and ACVR1 are widely expressed. BMPR1B shows a more restricted expression profile. ACVRL1 is limited to endothelial cells and a few other cell types. The binding specificities of BMPs to type I receptors is affected by the type II receptors that are present (Yu et al. 2005). Typically, BMP2 and BMP4 bind to BMPR1A and BMPR1B (ten Dijke et al. 1994). BMP6 and BMP7 bind strongly to ACVR1 and weakly to BMPR1B. Growth/differentiation factor 5 (BMP14, GDF5) preferentially binds to BMPR1B, but not to other type I receptors (Nishitoh et al. 1995). BMP9 and BMP10 bind to ACVRL1 and ACVRL (Scharpfenecker et al. 2007). BMP type I receptors are shared by other members of the TGFB family. Three receptors, Bone morphogenetic protein receptor type-2 (BMPR2), Activin receptor type-2A (ACVR2A) and Activin receptor type-2B (ACVR2B) are the type II receptors for mammalian BMPs. They are widely expressed in various tissues. BMPR2 is specific for BMPs, whereas ACVR2A and ACVR2B are shared with activins and myostatin. BMP binding and signalling can be affected by coreceptors. Glycosylphosphatidylinositol (GPI)-anchored proteins of the repulsive guidance molecule (RGM) family, including RGMA, RGMB (DRAGON) and Hemojuvelin (HFE2, RGMC) are coreceptors for BMP2 and BMP4, enhancing signaling (Samad et al. 2005, Babitt et al. 2005, 2006). They interact with BMP type I and/or type II receptors and bind BMP2 and BMP4, but not BMP7 or TGFB1. BMP2/4 signalling normally involves BMPR2, not ACVR2A or ACVR2B. Cells transfected with RGMA use both BMPR2 and ACVR2A for BMP-2/4 signalling, suggesting that RGMA facilitates the use of ACVR2A by BMP2/4 (Xia et al. 2007). Endoglin (ENG) is a transmembrane protein expressed in proliferating endothelial cells. It binds various ligands including TGFB1/3, Activin-A and BMP2/7 (Barbara et al. 1999). It inhibits TGFB-induced responses and enhances BMP7-induced responses (Scherner et al. 2007). Mutations in ENG result in hereditary haemorrhagic telangiectasia (HHT1), also known as OslerWeberRendu disease, while mutations in ACVRL1 lead to HHT2, suggesting that they act in a common signalling pathway (McAllister et al. 1994, Johnson et al. 1996). BMP2 is a dimeric protein, having two receptor-binding motifs. One is a high-affinity binding site for BMPR1A, the other is a low-affinity binding site for BMPR2 (Kirsch et al. 2000). In the absence of ligand stimulation, small fractions of type II and type I receptors are present as preexisting homodimers and heterodimers on the cell surface. Ligand-binding increases oligomerization. The intracellular domains of type I receptors have a characteristic GS domain (glycine and serine-rich domain) located N-terminal to the serine-threonine kinase domains. Type II receptor kinases are constitutively active in the absence of ligand. Upon ligand binding, the type II receptor kinase phosphorylates the GS domain of the type I receptor, a critical event in signal transduction by the serine/threonine kinase receptors (Miyazono et al. 2010). Activation of the TGFBR1 receptor has been studied in detail. The inactive conformation is maintained by interaction between the GS domain, the N-terminal lobe and the activation loop of the kinase (Huse et al. 1999). When the GS domain is phosphorylated by the type II receptor kinase, the TGFBR1 kinase is converted to an active conformation. Mutations of Thr-204 in TGFBR1 and the corresponding Gln in BMP type I receptors lead to their constitutive activation. The L45 loop, in the kinase domain of type I receptors, specifically interacts with receptor-regulated Smads (R-Smads). Neurotrophic tyrosine kinase receptor type 3 (NT-3 growth factor receptor, TrkC, NTRK3) directly binds BMPR2, interfereing with its interaction with BMPR1A, which inhibits downstream signalling (Jin et al. 2007). Tyrosine-protein kinase transmembrane receptor ROR2 and BMPR1B form a heteromeric complex in a ligand independent fashion that modulatesGDF5-BMPR1B signalling by inhibition of Smad1/5 signalling (Sammar et al. 2004). Type I receptor kinases activated by the type II receptor kinases, phosphorylate R-Smads. R-Smads then form a complex with common-partner Smad (co-Smad) and translocate to the nucleus. The oligomeric Smad complexes regulate the transcription of target genes through interaction with various transcription factors and transcriptional coactivators or corepressors. Inhibitory Smads (I-Smads) negatively regulate the action of R-Smads and/or co-Smads. Eight different Smads have been identified in mammals. Smad1, Smad5 and Smad8 are R-Smads in BMP signalling pathways (BMP-specific R-Smads). Smad2 and Smad3 are R-Smads in TGFB/activin signalling pathways. BMP receptors can phosphorylate Smad2 in certain types of cells (Murakami et al. 2009). Smad1, Smad5 and Smad8 are structurally highly similar to each other. The functional differences between them are largely unknown. Smad4 is the only co-Smad in mammals, shared by both BMP and TGFB/activin signalling pathways. Smad6 and Smad7 are I-Smads."
BMGC_PW0156,BMG_PW0328,"Activins are members of the TGF-beta superfamily of growth factors. The pathway plays important roles in embryonic development, inflammation and reproductive biology. Deregulation of activin signaling contributes to a number of pathological conditions. [GO:0032924, PID:200029, PMID:16885529, PMID:16997617, PMID:19273500, Reactome:R-HSA-1502540]",,"Activin was initially discovered as an activator of follicle stimulating hormone in the pituitary gland. It has since been shown to be an important participant in the differentiation of embryonic cells into mesodermal and endodermal layers. Activin binds the Activin receptor and triggers downstream events: phosphorylation of SMAD2 and SMAD3 followed by activation of gene expression (reviewed in Attisano et al. 1996, Willis et al. 1996, Chen et al. 2006, Hinck 2012). Activins are dimers comprising activin A (INHBA:INHBA), activin AB (INHBA:INHBB), and activin B (INHBB:INHBB). Activin first binds the type II receptor (ACVR2A, ACVR2B) and this complex then interacts with the type I receptor (ACVR1B, ACVR1C) (Attisano et al. 1996). The type II receptor phosphorylates the type I receptor and then the phosphorylated type I receptor phosphorylates SMAD2 and SMAD3. Dimers of phosphorylated SMAD2/3 bind SMAD4 and the resulting ternary complex enters the nucleus and activates target genes."
BMGC_PW0157,BMG_PW0329,"The cell-cell signaling pathway conveys information between cells using cell adhesion molecules. [GO:0007267, Reactome:R-HSA-1500931, RGD:InHouse_dictionary]",,"Cell-to-Cell communication is crucial for multicellular organisms because it allows organisms to coordinate the activity of their cells. Some cell-to-cell communication requires direct cell-cell contacts mediated by receptors on their cell surfaces. Members of the immunoglobulin superfamily (IgSF) proteins are some of the cell surface receptors involved in cell-cell recognition, communication and many aspects of the axon guidance and synapse formation-the crucial processes during embryonal development (Rougon & Hobert 2003). Processes annotated here as aspects of cell junction organization mediate the formation and maintenance of adherens junctions, tight junctions, and gap junctions, as well as aspects of cellular interactions with extracellular matrix and hemidesmosome assembly. Nephrin protein family interactions are central to the formation of the slit diaphragm, a modified adherens junction. Interactions among members of the signal regulatory protein family are important for the regulation of migration and phagocytosis by myeloid cells."
BMGC_PW0158,BMG_PW0351,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glycerophospholipids, also known as phospholipids. They are key components of membranes and some are also involved in signaling. [GO:0006650, KEGG:map00564, MCW_library:QU4_M235b_2009, SMP:00025]",,
BMGC_PW0159,BMG_PW0357,"The hypoxia inducible transcription factor is activated in response to hypoxic conditions to promote the expression of many genes that play important roles in glucose and energy metabolism, angiogenesis and erythropoiesis. [PID:200036, PID:200202, PMID:11181957, PMID:12603312, PMID:14597660, PMID:15031665, Reactome:R-HSA-1234158]",,"HIF-alpha (HIF1A, HIF2A (EPAS1), HIF3A) is translocated to the nucleus, possibly by two pathways: importin 4/7 (Chachami et al. 2009) and importin alpha/beta (Depping et al. 2008). Once in the nucleus HIF-alpha heterodimerizes with HIF-beta (ARNT) (Wang et al. 1995, Jiang et al. 1996, Tian et al. 1997, Gu et al. 1998, Erbel et al. 2003) and recruits CBP and p300 to promoters of target genes (Ebert and Bunn 1998, Kallio et al. 1998, Ema et al. 1999, Gu et al. 2001, Dames et al. 2002, Freedman et al. 2002)."
BMGC_PW0160,BMG_PW0360,"Leptin acts on two populations of hypothalamic neurons that express orexigenic (feeding inducing) and anorexigenic genes, respectively. Leptin reduces the expression of genes from the former and enhances the expression of genes from the latter neurons. The leptin mediated response acts primarily via Jak-dependent activation of STAT. [GO:0033210, PMID:11239410, PMID:12079865, Reactome:R-HSA-2586552]",,"Leptin (LEP, OB, OBS), a circulating adipokine, and its receptor LEPR (DB, OBR) control food intake and energy balance and are implicated in obesity-related diseases (recently reviewed in Amitani et al. 2013, Dunmore and Brown 2013, Cottrell and Mercer 2012, La Cava 2012, Marroqui et al. 2012, Paz-Filho et al. 2012, Denver et al. 2011, Lee 2011, Marino et al. 2011, Morton and Schwartz 2011, Scherer and Buettner 2011, Shan and Yeo 2011, Wauman and Tavernier 2011, Dardeno et al. 2010, Bjorbaek 2009, Morris and Rui 2009, Myers et al. 2008), including cancer (Guo et al. 2012), inflammation (Newman and Gonzalez-Perez 2013, Iikuni et al. 2008), and angiogenesis (Gonzalez-Perez et al. 2013). The identification of spontaneous mutations in the leptin gene (ob or LEP) and the leptin receptor gene (Ob-R, db or LEPR) genes in mice opened up a new field in obesity research. Leptin was discovered as the product of the gene affected by the ob (obesity) mutation, which causes obesity in mice. Likewise LEPR is the product of the gene affected by the db (diabetic) mutation. Leptin binding to LEPR induces canonical (JAK2/STATs; MAPK/ERK 1/2, PI-3K/AKT) and non-canonical signaling pathways (PKC, JNK, p38 MAPK and AMPK) in diverse cell types. The binding of leptin to the long isoform of LEPR (OB-Rl) initiates a phosphorylation cascade that results in transcriptional activation of target genes by STAT5 and STAT3 and activation of the PI3K pathway(not shown here), the MAPK/ERK pathway, and the mTOR/S6K pathway. Shorter LEPR isoforms with truncated intracellular domains are unable to activate the STAT pathway, but can transduce signals by way of activation of JAK2, IRS-1 or ERKs, including MAPKs. LEPR is constitutively bound to the JAK2 kinase. Binding of LEP to LEPR causes a conformational change in LEPR that activates JAK2 autophosphorylation followed by phosphorylation of LEPR by JAK2. Phosphorylated LEPR binds STAT3, STAT5, and SHP2 which are then phosphorylated by JAK2. Phosphorylated JAK2 binds SH2B1 which then binds IRS1/2, resulting in phosphorylation of IRS1/2 by JAK2. Phosphorylated STAT3 and STAT5 dimerize and translocate to the nucleus where they activate transcription of target genes (Jovanovic et al. 2010). SHP2 activates the MAPK pathway. IRS1/2 activate the PI3K/AKT pathway which may be the activator of mTOR/S6K. Several isoforms of LEPR have been identified (reviewed in Gorska et al. 2010). The long isoform (LEPRb, OBRb) is expressed in the hypothalamus and all types of immune cells. It is the only isoform known to fully activate signaling pathways in response to leptin. Shorter isoforms (LEPRa, LEPRc, LEPRd, and a soluble isoform LEPRe) are able to interact with JAK kinases and activate other pathways, however their roles in energy homeostasis are not fully characterized."
BMGC_PW0161,BMG_PW0367,"The aryl hydrocarbon receptor (AhR) is a transcription factor whose ligands include a variety of aromatic hydrocarbons and which regulates the expression of phase I and phase II drug- and xenobiotic-metabolizing enzymes. Phase I enzymes convert otherwise inactive hydrocarbons into active metabolites with potential carcinogenic effects, thus rendering AhR a player in tumor initiation. [PMID:15451023, PMID:15627472, PMID:20106901, PMID:20868221, Reactome:R-HSA-8937144]",,"The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that belongs to the basic helix-loop-helix/PER-ARNT-SIM family of DNA binding proteins and controls the expression of a diverse set of genes. Two major types of environmental compounds can activate AHR signaling: halogenated aromatic hydrocarbons such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polycyclic aromatic hydrocarbons (PAH) such as benzo(a)pyrene. Unliganded AHR forms a complex in the cytosol with two copies of 90kD heat shock protein (HSP90AB1), one X-associated protein (AIP), and one p23 molecular chaperone protein (PTGES3). After ligand binding and activation, the AHR complex translocates to the nucleus, disassociates from the chaperone subunits, dimerises with the aryl hydrocarbon receptor nuclear translocator (ARNT) and transactivates target genes via binding to xenobiotic response elements (XREs) in their promoter regions. AHR targets genes of Phase I and Phase II metabolism, such as cytochrome P450 1A1 (CYP1A1), cytochorme P450 1B1 (CYP1B1), NAD(P)H:quinone oxidoreductase I (NQO1) and aldehyde dehydrogenase 3 (ALHD3A1). This is thought to be an organism's response to foreign chemical exposure and normally, foreign chemicals are made less reactive by the induction and therefore increased activity of these enzymes (Beischlag et al. 2008). AHR itself is regulated by the aryl hydrocarbon receptor repressor (AHRR, aka BHLHE77, KIAA1234), an evolutionarily conserved bHLH-PAS protein that inhibits both xenobiotic-induced and constitutively active AHR transcriptional activity in many species. AHRR resides predominantly in the nuclear compartment where it competes with AHR for binding to ARNT. As a result, there is competition between AHR:ARNT and AHRR:ARNT complexes for binding to XREs in target genes and AHRR can repress the transcription activity of AHR (Hahn et al. 2009, Haarmann-Stemmann & Abel 2006)."
BMGC_PW0162,BMG_PW0370,"The glutathione conjugation of endogenous and exogenous electrophilic compounds represents a major pathway phase II biotransformation. The glutathione conjugates may either be excreted or undergo further processing. [MCW_-_book:QV_600_C335t_2001, PMID:17482904, Reactome:R-HSA-156590]",,"Glutathione S-Transferases (GSTs; EC 2.5.1.18) are another major set of phase II conjugation enzymes. They can be found in the cytosol as well as being microsomal membrane-bound. Cytosolic GSTs are encoded by at least 5 gene families (alpha, mu, pi, theta and zeta GST) whereas membrane-bound enzymes are encoded by single genes. Soluble GSTs are homo- or hetero-dimeric enzymes (approximately 25KDa subunits) which can act on a wide range of endogenous and exogenous electrophiles. GSTs mediate conjugation using glutathione (GSH), a tripeptide synthesized from its precursor amino acids gamma-glutamate, cysteine and glycine. A generalized reaction is RX + GSH -> HX + GSR Glutathione conjugates are excreted in bile and converted to cysteine and mercapturic acid conjugates in the intestine and kidneys. GSH is the major, low molecular weight, non-protein thiol synthesized de novo in mammalian cells. As well as taking part in conjugation reactions, GSH also has antioxidant ability and can metabolize endogenous and exogenous compounds. The nucleophilic GSH attacks the electrophilic substrate forming a thioether bond between the cysteine residue of GSH and the electrophile. The result is generally a less reactive and more water-soluble conjugate that can be easily excreted. In some cases, GSTs can activate compounds to reactive species such as certain haloalkanes and haloalkenes. Substrates for GSTs include epoxides, alkenes and compounds with electrophilic carbon, sulfur or nitrogen centres. There are two types of conjugation reaction with glutathione: displacement reactions where glutathione displaces an electron-withdrawing group and addition reactions where glutathione is added to activated double bond structures or strained ring systems."
BMGC_PW0163,BMG_PW0376,"Inhibition of protein folding or its disruption by mutant proteins in the endoplasmic reticulum triggers a signal transduction response known as the unfolded protein response (UPR). The UPR increases the biosynthetic capacity while decreasing the biosynthetic burden of the secretory pathway through up- and downregulation of gene expression. [GO:0030968, PMID:15603751, PMID:15952902, Reactome:R-HSA-381119]",,"The Unfolded Protein Response (UPR) is a regulatory system that protects the Endoplasmic Reticulum (ER) from overload. The UPR is provoked by the accumulation of improperly folded protein in the ER during times of unusually high secretion activity. Analysis of mutants with altered UPR, however, shows that the UPR is also required for normal development and function of secretory cells. One level at which the URP operates is transcriptional and translational regulation: mobilization of ATF6, ATF6B, CREB3 factors and IRE1 leads to increased transcription of genes encoding chaperones, while mobilization of PERK (pancreatic eIF2alpha kinase, EIF2AK3) leads to phosphorylation of the translation initiation factor eIF2alpha and global down-regulation of protein synthesis. ATF6, ATF6B, and CREB3 factors (CREB3 (LUMAN), CREB3L1 (OASIS), CREB3L2 (BBF2H7, Tisp40), CREB3L3 (CREB-H), and CREB3L4 (CREB4)) are membrane-bound transcription activators that respond to ER stress by transiting from the ER membrane to the Golgi membrane where their transmembrane domains are cleaved, releasing their cytosolic domains to transit to the nucleus and activate transcription of target genes. IRE1, also a resident of the ER membrane, dimerizes and autophosphorylates in response to ER stress. The activated IRE1 then catalyzes unconventional splicing of XBP1 mRNA to yield an XBP1 isoform that is targeted to the nucleus and activates chaperone genes."
BMGC_PW0164,BMG_PW0381,"The G2/M checkpoint pathways assure the genome is replicated only once per cell cycle. The checkpoints control for damaged and un-replicated DNA. Various DNA damage checkpoints lead to inhibition of the cyclin-dependent kinases that regulate the next cell cycle point. [GO:0007095, InHouse:PW_dictionary, Reactome:R-HSA-69473]",,
BMGC_PW0165,BMG_PW0382,"Those pathways that assure the genome is replicated only once per cell cycle. The checkpoints control for damaged and un-replicated DNA. Un-replicated DNA signals to block the cell cycle from proceeding. The mechanism by which the cell detects un-replicated DNA is not known. [InHouse:PW_dictionary, Reactome:R-HSA-69478]",,"The G2/M DNA replication checkpoint ensures that mitosis is not initiated until DNA replication is complete. If replication is blocked, the DNA replication checkpoint signals to maintain Cyclin B - Cdc2 complexes in their T14Y15 phosphorylated and inactive state. This prevents the phosphorylation of proteins involved in G2/M transition, and prevents mitotic entry. Failure of these checkpoints results in changes of ploidy: in the case of mitosis without completion of DNA replication, aneuploidy of <2C will result, and the opposite is true if DNA replication is completed more than once in a single cell cycle with an overall increase in ploidy. The mechanism by which unreplicated DNA is first detected by the cell is unknown."
BMGC_PW0166,BMG_PW0383,"A very close relative of Ras, the Rap1 mediated pathway appears to control diverse processes such as modulation of growth and differentiation, secretion, integrin-linked cell adhesion and morphogenesis. [GO:0032486, PMID:11331911, Reactome:R-HSA-392517]","Rap1 is a small GTPase that controls diverse processes, such as cell adhesion, cell-cell junction formation and cell polarity. Like all G proteins, Rap1 cycles between an inactive GDP-bound and an active GTP-bound conformation. A variety of extracellular signals control this cycle through the regulation of several unique guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). Rap1 plays a dominant role in the control of cell-cell and cell-matrix interactions by regulating the function of integrins and other adhesion molecules in various cell types. Rap1 also regulates MAP kinase (MAPK) activity in a manner highly dependent on the context of cell types.","Rap1 (Ras-proximate-1) is a small G protein in the Ras superfamily. Like all G proteins, Rap1 is activated when bound GDP is exchanged for GTP. Rap1 is targeted to lipid membranes by the covalent attachment of lipid moieties to its carboxyl terminus. Movement of Rap1 from endosomal membranes to the plasma membrane upon activation has been reported in several cell types including Jurkat T cells and megakaryocytes. On activation, Rap1 undergoes conformational changes that facilitate recruitment of a variety of effectors, triggering it's participation in integrin signaling, ERK activation, and others."
BMGC_PW0167,BMG_PW0385,"The reelin signaling pathway regulates neuronal positioning and may also play a role in synaptic plasticity. The reelin gene appears to be downregulated in schizophrenic brains but the link between the reelin pathway and the disease remains to be established. [GO:0038026, PID:200062, PMID:12764038, PMID:14715136, PMID:14993361, Reactome:R-HSA-8866376]",,"Reelin (RELN) is an extracellular, multifunctional signal glycoprotein that controls not only the positioning of neurons in the developing brain, but also their growth, maturation, and synaptic activity in the adult brain (Stranahan et al. 2013). Abnormal Reelin expression in the brain is implicated in a number of neuropsychiatric disorders including autism, schizophrenia, bipolar disorder and Alzheimer's disease (Folsom & Fatemi 2013)."
BMGC_PW0168,BMG_PW0391,"Dopamine signaling plays important roles in processes such as motivation, learning and movement. It also plays several roles in the periphery as a modulator of renal, cardiovascular and endocrine systems. Dopamine signals to a family of at least 5 receptors that are classified into two subfamilies that couple to distinct G proteins to elicit diverse downstream events. Deregulation of the pathway has been implicated in several neuropsychiatric and neurological disorders. [GO:0007212, KEGG:04728, PMID:17408758, PMID:18353279, Reactome:R-HSA-390651]","Dopamine (DA) is an important and prototypical slow neurotransmitter in the mammalian brain, where it controls a variety of functions including locomotor activity, motivation and reward, learning and memory, and endocrine regulation. Once released from presynaptic axonal terminals, DA interacts with at least five receptor subtypes in the central nervous system (CNS), which have been divided into two groups: the D1-like receptors (D1Rs), comprising D1 and D5 receptors, both positively coupled to adenylyl cyclase and cAMP production, and the D2-like receptors (D2Rs), comprising D2, D3, and D4 receptors, whose activation results in inhibition of adenylyl cyclase and suppression of cAMP production. In addition, D1Rs and D2Rs modulate intracellular Ca2+ levels and a number of Ca2+ -dependent intracellular signaling processes. Through diverse cAMP- and Ca2+-dependent and - independent mechanisms, DA influences neuronal activity, synaptic plasticity, and behavior. Presynaptically localized D2Rs regulate synthesis and release of DA as the main autoreceptor of the dopaminergic system.","Dopamine receptors play vital roles in processes such as the control of learning, motivation, fine motor control and modulation of neuroendocrine signaling (Giralt JA and Greengard P, 2004). Abnormalities in dopamine receptor signaling may lead to neuropsychiatric disorders such as Parkinson's disease and schizophrenia. Dopamine receptors are prominent in the CNS and the neurotransmitter dopamine is the primary endogenous ligand for these receptors. In humans, there are five distinct types of dopamine receptor, D1-D5. They are subdivided into two families; D1-like family (D1 and D5) which couple with the G protein alpha-s and are excitatory and D2-like family (D2,D3 and D4) which couple with the G protein alpha-i and are inhibitory (Kebabian JW and Calne DB, 1979)."
BMGC_PW0169,BMG_PW0394,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of cobalamin, known as vitamin B12 - a water-soluble vitamin. Cobalamin has important roles in a number of metabolic pathways. There are several related compounds whose synthesis occurs in bacteria but whose conversion can be carried out in higher organisms. [GO:0009235, https://en.wikipedia.org/wiki/Vitamin_B12 wikipedia, Reactome:R-HSA-196741]",,"Vitamin B12 (cobalamin) is a water soluble vitamin, consisting of a planar corrin ring coordinating with a cobalt atom through four nitrogen atoms. A 5,6 dimethylbenzamidizole base coordinates with the cobalt atom in the lower axial position. Groups that can coordinate with the cobalt atom in the upper axial position include methyl (methylcobalamin, MetCbl), adenosyl (adenosylcobalamin, AdoCbl) and cyano (cyanocobalamin (CNCbl)). Only bacteria and archaea synthesise cobalamin so humans need a dietary intake to prevent deficiency. Food derived from animals provides cobalamins (RCbl) including MeCbl and AdoCbl. CNCbl, a semi synthetic form of the vitamin produced from bacterial hydroxocobalamin is provided by many pharmaceuticals, supplements, and food additives. Cbl derivatives function as cofactors in two reactions, AdoCbl in the conversion of homocysteine to methionine and MetCbl in the conversion of L-methylmalonyl CoA to succinyl CoA. Both reactions are essential for normal human function, however, and defects in the steps by which Cbl or CNCbl is taken up from the diet, transported to metabolically active cells, and transformed to AdoCbl and MeCbl are associated with severe defects in blood formation and neural function (Banerjee et al. 2021, Froese & Gravel 2010, Green 2010, Nielsen et al. 2012, Quadros 2010; Seetharam 1999). The overall process of Cbl utilization is presented here in three parts: its uptake from the diet into gut enterocytes, its release into the blood, circulation within the body (including renal re-uptake), and delivery to the cells where it is used, and its metabolism in those cells to generate AdoCbl and MeCbl."
BMGC_PW0170,BMG_PW0401,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of creatine. Officially methyl guanidino-acetic acid formed from arginine and glycine and the methyl group of methionine, creatine supplies energy to muscle cells. [GO:0006600, Onelook:www.onelook.com, PMID:10893433, Reactome:R-HSA-71288]",,"In humans, creatine is synthesized primarily in the liver and kidney, from glycine, arginine, and S-adenosylmethionine, in a sequence of two reactions. From the liver, creatine is exported to tissues such as skeletal muscle and brain, where it undergoes phosphorylation and serves as a short-term energy store. The mechanism by which creatine leaves producer tissues is unclear, but its uptake by consumer tissues is mediated by the SLC6A8 transporter. Once formed, phosphocreatine undergoes a slow spontaneous reaction to form creatinine, which is excreted from the body."
BMGC_PW0171,BMG_PW0407,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of serotonin - an amine neurotransmitter that is believed to play important roles in a number of conditions such as depression, bipolar disorder and anxiety. [GO:0042428, OneLook:www.onelook.com, Reactome:R-HSA-380612]",,Serotonin is first metabolized to 5-hydroxyindole acetaldehyde by monoamine oxidase. 5-hydroxyindole acetaldehyde is then catalyzed by aldehyde dehydrogenase to form 5-hydroxyindole acetic acid.
BMGC_PW0172,BMG_PW0409,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of gamma-aminobutyric acid (GABA), the central nervous system's main inhibitory neurotransmitter, involved in reducing neuronal excitability throughout the system. [GO:0009448, http://www.onelook.com OneLook, Reactome:R-HSA-888590]",,"GABA is a major inhibitory neurotransmitter in the mammalian central nervous system. GABA modulates neuronal excitability throughout the nervous system. Disruption of GABA neurotransmission leads to many neurological diseases including epilepsy and a general anxiety disorder. GABA is synthesized by two distinct enzymes GAD67 and GAD65 that differ in their cellular localization, functional properties and co-factor requirements. GABA synthesized by GAD65 is used for neurotransmission whereas GABA synthesized by GAD67 is used for processes other than neurotransmission such as synaptogenesis and protection against neuronal injury. GABA is loaded into synaptic vesicle with the help of vesicular inhibitory amino acid transporter or VGAT. GAD65 and VGAT are functionally linked at the synaptic vesicle membrane and GABA synthesized by GAD65 is preferentially loaded into the synaptic vesicle over GABA synthesized in cytoplasm by GAD67.The GABA loaded synaptic vesicles are docked at the plasma membrane with the help of the SNARE complexes and primed by interplay between various proteins including Munc18, complexin etc. Release of GABA loaded synaptic vesicle is initiated by the arrival of action potential at the presynaptic bouton and opening of N or P/Q voltage gated Ca2+ channels. Ca2+ influx results in Ca2+ binding by synaptobrevin, which is a part of the SNARE complex that also includes SNAP25 and syntaxin, leading to synaptic vesicle fusion. Release of GABA in the synaptic cleft leads to binding of GABA by the GABA receptors and post ligand binding events."
BMGC_PW0173,BMG_PW0410,"Those metabolic reactions involved in the degradation of heme - an iron-containing compound where the iron is complexed within a porphyrin heterocyclic ring, There are several kinds of hemes depending on the composition of their side chain. Heme serves as a prosthetic group for a number of proteins. [GO:0042167, PMID:24782769, Reactome:R-HSA-189483]",,"Most of the heme degraded in humans comes from hemoglobin. Approximately 6-8 grams of hemoglobin is degraded daily which is equivalent to approximately 300 milligrams of heme per day. Heme is not recycled so it must be degraded and excreted. The iron, however, is conserved. There are two steps to heme degradation; 1. cleavage of the heme ring by a microsomal heme oxygenase producing biliverdin 2. biliverdin is reduced to bilirubin. Bilirubin can then be conjugated with glucuronic acid and excreted."
BMGC_PW0174,BMG_PW0413,"A pathway of protein modification via conjugation with SUMO (small ubiquitin-related modifier). SUMOylation does not target proteins to the proteasome, rather it targets proteins to particular cellular compartments. [GO:0016925, PMID:10806345, PMID:15808504, PMID:23328396, PMID:23416108, Reactome:R-HSA-2990846]",,"Small Ubiquitin-like MOdifiers (SUMOs) are a family of 3 proteins (SUMO1,2,3) that are reversibly conjugated to lysine residues of target proteins via a glycine-lysine isopeptide bond (reviewed in Hay 2013, Hannoun et al. 2010, Gareau and Lima 2010, Wilkinson and Henley 2010, Wang and Dasso 2009). Proteomic methods have yielded estimates of hundreds of target proteins. Targets are mostly located in the nucleus and therefore SUMOylation disproportionately affects gene expression. SUMOs are initially translated as proproteins possessing extra amino acid residues at the C-terminus which are removed by the SUMO processing endoproteases SENP1,2,5 (Hay 2007). Different SENPs have significantly different efficiencies with different SUMOs. The processing exposes a glycine residue at the C-terminus that is activated by ATP-dependent thiolation at cysteine-173 of UBA2 in a complex with SAE1, the E1 complex. The SUMO is transferred from E1 to cysteine-93 of a single E2 enzyme, UBC9 (UBE2I). UBC9 with or, in some cases, without an E3 ligase conjugates the glycine C-terminus of SUMO to an epsilon amino group of a lysine residue on the target protein. SUMO2 and SUMO3 may then be further polymerized, forming chains. SUMO1 is unable to form polymers. Conjugated SUMO can act as a biinding site for proteins possessing SUMO interaction motifs (SIMs) and can also directly affect the formation of complexes between the target protein and other proteins. Conjugated SUMOs are removed by cleavage of the isopeptide bond by processing enzymes SENP1,2,3,5. The processing enzymes SENP6 and SENP7 edit chains of SUMO2 and SUMO3."
BMGC_PW0175,BMG_PW0416,"The pathways by which water flows into and out of the cell and into and out of sub-cellular compartments for multi-cellular organisms, mediated by members of the aquaporin family of water channels (WCP). The 13 members identified in mammals are grouped into three subfamilies: aquaporins, selective for water; aquaglyceroporins, permeable to both water and small molecules; superaquaporins, the sub-cellular aquaporins. WCPs belong to the superfamily of major intrinsic proteins (MIPs). [GO:0006833, PMID:19165894, Reactome:R-HSA-445717]",,"Aquaporins (AQP's) are six-pass transmembrane proteins that form channels in membranes. Each monomer contains a central channel formed in part by two asparagine-proline-alanine motifs (NPA boxes) that confer selectivity for water and/or solutes. The monomers assemble into tetramers. During passive transport by Aquaporins most aquaporins (i.e. AQP0/MIP, AQP1, AQP2, AQP3, AQP4, AQP5, AQP7, AQP8, AQP9, AQP10) transport water into and out of cells according to the osmotic gradient across the membrane. Four aquaporins (the aquaglyceroporins AQP3, AQP7, AQP9, AQP10) conduct glycerol, three aquaporins (AQP7, AQP9, AQP10) conduct urea, and one aquaporin (AQP6) conducts anions, especially nitrate. AQP8 also conducts ammonia in addition to water. AQP11 and AQP12, classified as group III aquaporins, were identified as a result of the genome sequencing project and are characterized by having variations in the first NPA box when compared to more traditional aquaporins. Additionally, a conserved cysteine residue is present about 9 amino acids downstream from the second NPA box and this cysteine is considered indicative of group III aquaporins. Purified AQP11 incorporated into liposomes showed water transport. Knockout mice lacking AQP11 had fatal cyst formation in the proximal tubule of the kidney. Exogenously expressed AQP12 showed intracellular localization. AQP12 is expressed exclusively in pancreatic acinar cells. Aquaporins are important in fluid and solute transport in various tissues. During Transport of glycerol from adipocytes to the liver by Aquaporins, glycerol generated by triglyceride hydrolysis is exported from adipocytes by AQP7 and is imported into liver cells via AQP9. AQP1 plays a role in forming cerebrospinal fluid and AQP1, AQP4, and AQP9 appear to be important in maintaining fluid balance in the brain. AQP0, AQP1, AQP3, AQP4, AQP8, AQP9, and AQP11 play roles in the physiology of the hepatobiliary tract. In the kidney, water and solutes are passed out of the bloodstream and into the proximal tubule via the slit-like structure formed by nephrin in the glomerulus. Water is reabsorbed from the filtrate during its transit through the proximal tubule, the descending loop of Henle, the distal convoluted tubule, and the collecting duct. Aquaporin-1 (AQP1) in the proximal tubule and the descending thin limb of Henle is responsible for about 90% of reabsorption (as estimated from mouse knockouts of AQP1). AQP1 is located on both the apical and basolateral surface of epithelial cells and thus transports water through the epithelium and back into the bloodstream. In the collecting duct epithelial cells have AQP2 on their apical surfaces and AQP3 and AQP4 on their basolateral surfaces to transport water across the epithelium. Vasopressin regulates renal water homeostasis via Aquaporins by regulating the permeability of the epithelium through activation of a signaling cascade leading to the phosphorylation of AQP2 and its translocation from intracellular vesicles to the apical membrane of collecting duct cells. Here, three views of aquaporin-mediated transport have been annotated: a generic view of transport mediated by the various families of aquaporins independent of tissue type (Passive transport by Aquaporins), a view of the role of specific aquaporins in maintenance of renal water balance (Vasopressin regulates renal water homeostasis via Aquaporins), and a view of the role of specific aquaporins in glycerol transport from adipocytes to the liver (Transport of glycerol from adipocytes to the liver by Aquaporins)."
BMGC_PW0176,BMG_PW0431,"A pathway of protein modification via conjugation with ubiquitin. Ubiquitination is well known for targeting proteins for degradation. However, ubiquitination is also used as a tag that modulates the signaling outcomes of modified substrates. [GO:0016567, PMID:10806345, PMID:21135871, PMID:22420778, Reactome:R-HSA-8852135]",,"Ubiquitin is a small, 76 amino acid residue protein that is conjugated by E3 ubiquitin ligases to other proteins in order to regulate their function or degradation (enzymatic cascade reviewed in Neutzner and Neutzner 2012, Kleiger and Mayor 2014, structures and mechanisms of conjugating enzymes reviewed in Lorenz et al. 2013). Ubiquitination of target proteins usually occurs between the C-terminal glycine residue of ubiquitin and a lysine residue of the target, although linkages with cysteine, serine, and threonine residues are also observed (reviewed in Wang et al. 2012, McDowell and Philpott 2013). Ubiquitin must first be processed from larger precursors and then activated by formation of a thiol ester bond between ubiquitin and an E1 activating enzyme (UBA1 or UBA6) and transfer to an E2 conjugating enzyme before being transferred by an E3 ligase to a target protein. Precursor proteins containing multiple ubiquitin monomers (polyubiquitins) are produced from the UBB and UBC genes; precursors containing a single ubiquitin monomer and a ribosomal protein are produced from the UBA52 and RPS27A genes. Many proteases (deubiquitinases) may potentially process these precursors yielding monomeric ubiquitin. The proteases OTULIN and USP5 are particularly active in cleaving the polyubiquitin precursors, whereas the proteases UCHL3, USP7, and USP9X cleave the ubiquitin-ribosomal protein precursors yielding ubiquitin monomers (Grou et al. 2015). A resultant ubiquitin monomer is activated by adenylation of the C-terminal glycine followed by conjugation of the C-terminus to a cysteine residue of the E1 enzymes UBA1 or UBA6 via a thiol ester bond. The ubiquitin is then transferred from the E1 enzyme to a cysteine residue of one of several E2 enzymes (reviewed in van Wijk and Timmers 2010, Stewart et al. 2016). Through a less well characterized mechanism, E3 ubiquitin ligases then bring a target protein and the E2-ubiquitin conjugate into proximity so that the ubiquitin is transferred via formation of an amide bond to a particular lysine residue (or, in rarer cases, a thiol ester bond to a cysteine residue or an ester bond to a serine or threonine residue) of the target protein (reviewed in Berndsen and Wolberger 2014). Based on protein homologies, families of E3 ubiquitin ligases have been identified that include RING-type ligases (reviewed in Deshaies et al. 2009, Metzger et al. 2012, Metzger et al. 2014), HECT-type ligases (reviewed in Rotin et al. 2009, Metzger et al. 2012), and RBR-type ligases (reviewed in Dove et al. 2016). A subset of the RING-type ligases participate in CULLIN-RING ligase complexes (CRLs which include SCF complexes, reviewed in Lee and Zhou 2007, Genschik et al. 2013, Skaar et al. 2013, Lee et al. 2014). Some E3-E2 combinations catalyze mono-ubiquitination of the target protein (reviewed in Nakagawa and Nakayama 2015). Other E3-E2 combinations catalyze conjugation of further ubiquitin monomers to the initial ubiquitin, forming polyubiquitin chains. (It may also be possible for some E3-E2 combinations to preassemble polyubiquitin and transfer it as a unit to the target protein.) Ubiquitin contains several lysine (K) residues and a free alpha amino group to which further ubiquitin can be conjugated. Thus different types of polyubiquitin are possible: K11 linked polyubiquitin is observed in endoplasmic reticulum-associated degradation (ERAD), K29 linked polyubiquitin is observed in lysosomal degradation, K48 linked polyubiquitin directs target proteins to the proteasome for degradation, whereas K63 linked polyubiquitin generally acts as a scaffold to recruit other proteins in several cellular processes, notably DNA repair (reviewed in Komander et al. 2009). Ubiquitination is highly regulated (reviewed in Vittal et al. 2015) and affects all cellular processes including DNA damage response (reviewed in Brown and Jackson 2015), immune signaling (reviewed in Park et al. 2014, Lutz-Nicoladoni et al. 2015), and regulation of normal and cancerous cell growth (reviewed in Skaar and Pagano 2009, Yerlikaya and Yontem 2013, Strikoudis et al. 2014)."
BMGC_PW0177,BMG_PW0451,"Those metabolic reactions involved in the synthesis of cholesterol, an essential sterol component of mammalian cell membrane. Cholesterol is the precursor of all steroid hormones. [GO:0006695, OneLook:www.onelook.com, Reactome:R-HSA-191273, SMP:00023]",,"Cholesterol is synthesized de novo from acetyl CoA. The overall synthetic process is outlined in the attached illustration. Enzymes whose regulation plays a major role in determining the rate of cholesterol synthesis in the body are highlighted in red, and connections to other metabolic processes are indicated. The transformation of zymosterol into cholesterol can follow either of routes, one in which reduction of the double bond in the isooctyl side chain is the final step (cholesterol synthesis via desmosterol, also known as the Bloch pathway) and one in which this reduction is the first step (cholesterol biosynthesis via lathosterol, also known as the Kandutsch-Russell pathway). The former pathway is prominent in the liver and many other tissues while the latter is prominent in skin, where it may serve as the source of the 7-dehydrocholesterol that is the starting point for the synthesis of D vitamins. Defects in several of the enzymes involved in this process are associated with human disease and have provided useful insights into the regulatory roles of cholesterol and its synthetic intermediates in human development (Gaylor 2002; Herman 2003; Kandutsch & Russell 1960; Mitsche et al. 2015; Song et al. 2005)."
BMGC_PW0178,BMG_PW0457,"Those metabolic reactions involved in the synthesis, utilization and/or conversion of arachidonic acid - a polyunsaturated, omega-6 fatty acid. It is a precursor in the production of eicosanoids and can also be converted to other metabolites, collectively known as the arachidonic acid cascade. [GO:0019369, KEGG:map00590, OneLook:www.onelook.com, PMID:15896353, Reactome:R-HSA-2142753, SMP:00075]",,"Eicosanoids, oxygenated, 20-carbon fatty acids, are autocrine and paracrine signaling molecules that modulate physiological processes including pain, fever, inflammation, blood clot formation, smooth muscle contraction and relaxation, and the release of gastric acid. Eicosanoids are synthesized in humans primarily from arachidonate (all-cis 5,8,11,14-eicosatetraenoate) that is released from membrane phospholipids. Once released, arachidonate is acted on by prostaglandin G/H synthases (PTGS, also known as cyclooxygenases (COX)) to form prostaglandins and thromboxanes, by arachidonate lipoxygenases (ALOX) to form leukotrienes, epoxygenases (cytochrome P450s and epoxide hydrolase) to form epoxides such as 15-eicosatetraenoic acids, and omega-hydrolases (cytochrome P450s) to form hydroxyeicosatetraenoates (Buczynski et al. 2009, Vance & Vance 2008). Levels of free arachidonate in the cell are normally very low so the rate of synthesis of eicosanoids is determined primarily by the activity of phospholipase A2, which mediates phospholipid cleavage to generate free arachidonate. The enzymes involved in arachidonate metabolism are typically constitutively expressed so the subset of these enzymes expressed by a cell determines the range of eicosanoids it can synthesize. Eicosanoids are unstable, undergoing conversion to inactive forms with half-times under physiological conditions of seconds or minutes. Many of these reactions appear to be spontaneous."
BMGC_PW0179,BMG_PW0471,"The coagulation cascade is the series of events proceeding via the tissue factor (extrinsic) or the contact activation (intrinsic) pathway and converging in the formation of fibrin clots. Several anticoagulation systems are in place to modulate the pathway. The coagulation cascade and the complement pathway of immune responses are connected in a cross talk. [GO:0072378, KEGG:04610, PMID:26018600, PMID:26149013, Reactome:R-HSA-140877]","The complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation: the classical pathway, the lectin pathway, and the alternative pathway. All of these pathways generate a crucial enzymatic activity that, in turn, generates the effector molecules of complement. The main consequences of complement activation are the opsonization of pathogens, the recruitment of inflammatory and immunocompetent cells, and the direct killing of pathogens. Blood coagulation is another series of proenzyme-to-serine protease conversions, culminating the formation of thrombin, the enzyme responsible for the conversion of soluble fibrinogen to the insoluble fibrin clot. Protease-activated receptors, such as those activated by thrombin, are members of G protein-coupled receptors and function as a mediator of innate immunity. The kallikrein-kinin system is an endogenous metabolic cascade, triggering of which results in the release of vasoactive kinins (bradykinin-related peptides). Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning.","The formation of a fibrin clot at the site of an injury to the wall of a normal blood vessel is an essential part of the process to stop blood loss after vascular injury. The reactions that lead to fibrin clot formation are commonly described as a cascade, in which the product of each step is an enzyme or cofactor needed for following reactions to proceed efficiently. The entire clotting cascade can be divided into three portions, the extrinsic pathway, the intrinsic pathway, and the common pathway. The extrinsic pathway begins with the release of tissue factor at the site of vascular injury and leads to the activation of factor X. The intrinsic pathway provides an alternative mechanism for activation of factor X, starting from the activation of factor XII. The common pathway consists of the steps linking the activation of factor X to the formation of a multimeric, cross-linked fibrin clot. Each of these pathways includes not only a cascade of events that generate the catalytic activities needed for clot formation, but also numerous positive and negative regulatory events."
BMGC_PW0180,BMG_PW0472,"Hemostasis is the response to blood vessel injury to prevent blood loss via platelet-mediated primary homeostasis and the secondary homeostasis of coagulation. The latter is a complex cascade which is triggered by the innate immune response and inflammation. [GO:0007599, PMID:26018600, Reactome:R-HSA-109582]",,"Hemostasis is a physiological response that culminates in the arrest of bleeding from an injured vessel. Under normal conditions the vascular endothelium supports vasodilation, inhibits platelet adhesion and activation, suppresses coagulation, enhances fibrin cleavage and is anti-inflammatory in character. Under acute vascular trauma, vasoconstrictor mechanisms predominate and the endothelium becomes prothrombotic, procoagulatory and proinflammatory in nature. This is achieved by a reduction of endothelial dilating agents: adenosine, NO and prostacyclin; and by the direct action of ADP, serotonin and thromboxane on vascular smooth muscle cells to elicit their contraction (Becker et al. 2000). The chief trigger for the change in endothelial function that leads to the formation of a haemostatic thrombus is the loss of the endothelial cell barrier between blood and extracellular matrix components (Ruggeri 2002). Circulating platelets identify and discriminate areas of endothelial lesions; here, they adhere to the exposed sub endothelium. Their interaction with the various thrombogenic substrates and locally generated or released agonists results in platelet activation. This process is described as possessing two stages, firstly, adhesion - the initial tethering to a surface, and secondly aggregation - the platelet-platelet cohesion (Savage & Cattaneo et al. 2001). Three mechansism contribute to the loss of blood following vessel injury. The vessel constricts, reducing the loss of blood. Platelets adhere to the site of injury, become activated and aggregate with fibrinogen into a soft plug that limits blood loss, a process termed primary hemostasis. Proteins and small molecules are released from granules by activated platelets, stimulating the plug formation process. Fibrinogen from plasma forms bridges between activated platelets. These events initiate the clotting cascade (secondary hemostasis). Negatively-charged phospholipids exposed at the site of injury and on activated platelets interact with tissue factor, leading to a cascade of reactions that culminates with the formation of an insoluble fibrin clot."
BMGC_PW0181,BMG_PW0478,"The steps leading to the activation of plasminogen and the subsequent breaking down of a fibrin clot - the product of the coagulation cascade. [GO:0042730, PMID:26149056, Reactome:R-HSA-75205]",,"The crosslinked fibrin multimers in a clot are broken down to soluble polypeptides by plasmin, a serine protease. Plasmin can be generated from its inactive precursor plasminogen and recruited to the site of a fibrin clot in two ways, by interaction with tissue plasminogen activator at the surface of a fibrin clot, and by interaction with urokinase plasminogen activator at a cell surface. The first mechanism appears to be the major one responsible for the dissolution of clots within blood vessels. The second, although capable of mediating clot dissolution, may normally play a major role in tissue remodeling, cell migration, and inflammation (Chapman 1997; Lijnen 2001). Clot dissolution is regulated in two ways. First, efficient plasmin activation and fibrinolysis occur only in complexes formed at the clot surface or on a cell membrane - proteins free in the blood are inefficient catalysts and are rapidly inactivated. Second, both plasminogen activators and plasmin itself are inactivated by specific serpins, proteins that bind to serine proteases to form stable, enzymatically inactive complexes (Kohler and Grant 2000). These events are outlined in the drawing: black arrows connect the substrates (inputs) and products (outputs) of individual reactions, and blue lines connect output activated enzymes to the other reactions that they catalyze."
BMGC_PW0182,BMG_PW0479,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of lipoproteins - any of the protein-lipid complexes. In the blood, lipoproteins carry fats essential for the cell. Genetic variability and environmental (nongenetic) factors contribute to alterations in the homeostasis of lipid metabolic pathways and constitute cardiovascular disease risk. [GO:0042157, PMID:16011471, Reactome:R-HSA-174824]",,"Because of their hydrophobicity, lipids are found in the extracellular spaces of the human body primarily in the form of lipoprotein complexes. Chylomicrons form in the small intestine and transport dietary lipids to other tissues in the body. Very low density lipoproteins (VLDL) form in the liver and transport triacylglycerol synthesized there to other tissues of the body. As they circulate, VLDL are acted on by lipoprotein lipases on the endothelial surfaces of blood vessels, liberating fatty acids and glycerol to be taken up by tissues and converting the VLDL first to intermediate density lipoproteins (IDL) and then to low density lipoproteins (LDL). IDL and LDL are cleared from the circulation via a specific cell surface receptor, found in the body primarily on the surfaces of liver cells. High density lipoprotein (HDL) particles, initially formed primarily by the liver, shuttle several kinds of lipids between tissues and other lipoproteins. Notably, they are responsible for the so-called reverse transport of cholesterol from peripheral tissues to LDL for return to the liver. Three aspects of lipoprotein function are currently annotated in Reactome: chylomicron-mediated lipid transport, LDL endocytosis and degradation, and HDL-mediated lipid transport, each divided into assembly, remodeling, and clearance subpathways."
BMGC_PW0183,BMG_PW0483,"Peptides generated from proteolytic degradation of cytosolic proteins are translocated to the ER where they associate with class I MHC molecules. Peptide-class I MHC complexes move through the Golgi and are transported to the cell surface to be recognized by CD8+ T cells. [GO:0002474, MCW:Handbook_on_cellular_nad_molecular_immunology, PMID:16181325, Reactome:R-HSA-983169]",,"Major histocompatibility complex (MHC) class I molecules play an important role in cell mediated immunity by reporting on intracellular events such as viral infection, the presence of intracellular bacteria or tumor-associated antigens. They bind peptide fragments of these proteins and presenting them to CD8+ T cells at the cell surface. This enables cytotoxic T cells to identify and eliminate cells that are synthesizing abnormal or foreign proteins. MHC class I is a trimeric complex composed of a polymorphic heavy chain (HC or alpha chain) and an invariable light chain, known as beta2-microglobulin (B2M) plus an 8-10 residue peptide ligand. Represented here are the events in the biosynthesis of MHC class I molecules, including generation of antigenic peptides by the ubiquitin/26S-proteasome system, delivery of these peptides to the endoplasmic reticulum (ER), loading of peptides to MHC class I molecules and display of MHC class I complexes on the cell surface."
BMGC_PW0184,BMG_PW0484,"Peptides generated from enzymatic degradation of proteins internalized in late endosomes or lysosomes bind to class II MHC molecules. Peptide-class II MHC complexes are delivered to the cell surface to be recognized by CD4+ T cells. [GO:0002495, MCW:Handbook_on_cellular_and_molecular_immunology, PMID:16181322, Reactome:R-HSA-2132295]",,"Antigen presenting cells (APCs) such as B cells, dendritic cells (DCs) and monocytes/macrophages express major histocompatibility complex class II molecules (MHC II) at their surface and present exogenous antigenic peptides to CD4+ T helper cells. CD4+ T cells play a central role in immune protection. On their activation they stimulate differentiation of B cells into antibody-producing B-cell blasts and initiate adaptive immune responses. MHC class II molecules are transmembrane glycoprotein heterodimers of alpha and beta subunits. Newly synthesized MHC II molecules present in the endoplasmic reticulum bind to a chaperone protein called invariant (Ii) chain. The binding of Ii prevents the premature binding of self antigens to the nascent MHC molecules in the ER and also guides MHC molecules to endocytic compartments. In the acidic endosomal environment, Ii is degraded in a stepwise manner, ultimately to free the class II peptide-binding groove for loading of antigenic peptides. Exogenous antigens are internalized by the APC by receptor mediated endocytosis, phagocytosis or pinocytosis into endocytic compartments of MHC class II positive cells, where engulfed antigens are degraded in a low pH environment by multiple acidic proteases, generating MHC class II epitopes. Antigenic peptides are then loaded into the class II ligand-binding groove. The resulting class II peptide complexes then move to the cell surface, where they are scanned by CD4+ T cells for specific recognition (Berger & Roche 2009, Zhou & Blum 2004, Watts 2004, Landsverk et al. 2009)."
BMGC_PW0185,BMG_PW0499,"The complement system is an important effector of innate and also of humoral adaptive immunity. It consists of three biochemical cascades that are differently initiated but share similar late steps and effector functions. The complement pathway and the coagulation cascade are connected in a cross talk. [GO:0006956, KEGG:04610, PMID:11287977, PMID:26149013, Reactome:R-HSA-166658]","The complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation: the classical pathway, the lectin pathway, and the alternative pathway. All of these pathways generate a crucial enzymatic activity that, in turn, generates the effector molecules of complement. The main consequences of complement activation are the opsonization of pathogens, the recruitment of inflammatory and immunocompetent cells, and the direct killing of pathogens. Blood coagulation is another series of proenzyme-to-serine protease conversions, culminating the formation of thrombin, the enzyme responsible for the conversion of soluble fibrinogen to the insoluble fibrin clot. Protease-activated receptors, such as those activated by thrombin, are members of G protein-coupled receptors and function as a mediator of innate immunity. The kallikrein-kinin system is an endogenous metabolic cascade, triggering of which results in the release of vasoactive kinins (bradykinin-related peptides). Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning.","In the complement cascade, a panel of soluble molecules rapidly and effectively senses a danger or damage and triggers reactions to provide a response that discriminates among foreign intruders, cellular debris, healthy and altered host cells (Ricklin D et al. 2010). Complement proteins circulate in the blood stream in functionally inactive states. When triggered the complement cascade generates enzymatically active molecules (such as C3/C5 convertases) and biological effectors: opsonins (C3b, C3d and C4b), anaphylatoxins (C3a and C5a), and C5b, which initiates assembly of the lytic membrane attack complex (MAC). Three branches lead to complement activation: the classical, lectin and alternative pathways (Kang YH et al. 2009; Ricklin D et al. 2010). The classical pathway is initiated by C1 complex binding to immune complexes, pentraxins or other targets such as apoptotic cells leading to cleavage of C4 and C2 components and formation of the classical C3 convertase, C4bC2a. The lectin pathway is activated by binding of mannan-binding lectin (MBL) to repetitive carbohydrate residues, or by binding of ficolins to carbohydrate or acetylated groups on target surfaces. MBL and ficolins interact with MBL-associated serine proteases (MASP) leading to cleavage of C4 and C2 and formation of the classical C3 convertase, C4bC2a. The alternative pathway is spontaneously activated by the hydrolysis of the internal thioester group of C3 to give C3(H2O). Alternative pathway activation involves interaction of C3(H2O) and/or previously generated C3b with factor B, which is cleaved by factor D to generate the alternative C3 convertases C3(H2O)Bb and/or C3bBb. All three pathways merge at the proteolytic cleavage of component C3 by C3 convertases to form opsonin C3b and anaphylatoxin C3a. C3b covalently binds to glycoproteins scattered across the target cell surface. This is followed by an amplification reaction that generates additional C3 convertases and deposits more C3b at the local site. C3b can also bind to C3 convertases switching them to C5 convertases, which mediate C5 cleavage leading to MAC formation. Thus, the activation of the complement system leads to several important outcomes: opsonization of target cells to enhance phagocytosis, lysis of target cells via membrane attack complex (MAC) assembly on the cell surface, production of anaphylatoxins C3a/C5a involved in the host inflammatory response, C5a-mediated leukocyte chemotaxis, and clearance of antibody-antigen complexes. The complement system is able to distinguish between pathological and physiological challenges, i.e. the outcomes of complement activation are predetermined by the trigger and are tightly tuned by a combination of initiation events with several regulatory mechanisms. These regulatory mechanisms use soluble (e.g., C4BP, CFI and CFH) and membrane-bound regulators (e.g., CR1, CD46(MCP), CD55(DAF) and CD59) and are coordinated by complement receptors such as CR1, CR2, etc. In response to microbial infection complement activation results in flagging microorganisms with opsonins for facilitated phagocytosis, formation of MAC on cells such as Gram-negative bacteria leading to cell lysis, and release of C3a and C5a to stimulate downstream immune responses and to attract leukocytes. Most pathogens can be eliminated by these complement-mediated host responses, though some pathogenic microorganisms have developed ways of avoiding complement recognition or blocking host complement attack resulting in greater virulence (Lambris JD et al. 2008; Serruto D et al. 2010). All three complement pathways (classical, lectin and alternative) have been implicated in clearance of dying cells (Mevorach D et al. 1998; Ogden CA et al. 2001; Gullstrand B et al.2009; Kemper C et al. 2008). Altered surfaces of apoptotic cells are recognized by complement proteins leading to opsonization and subsequent phagocytosis. In contrast to pathogens, apoptotic cells are believed to induce only a limited complement activation by allowing opsonization of altered surfaces but restricting the terminal pathway of MAC formation (Gershov D et al. 2000; Braunschweig A and Jozsi M 2011). Thus, opsonization facilitates clearance of dying cells and cell debris without triggering danger signals and further inflammatory responses (Fraser DA et al. 2007, 2009; Benoit ME et al. 2012). C1q-mediated complement activation by apoptotic cells has been shown in a variety of human cells: keratinocytes, human umbilical vein endothelial cells (HUVEC), Jurkat T lymphoblastoid cells, lung adenocarcinoma cells (Korb LC and Ahearn JM 1997; Mold C and Morris CA 2001; Navratil JS et al. 2001; Nauta AJ et al. 2004). In addition to C1q the opsonization of apoptotic Jurkat T cells with MBL also facilitated clearance of these cells by both dendritic cells (DC) and macrophages (Nauta AJ et al. 2004). Also C3b, iC3b and C4b deposition on apoptotic cells as a consequence of activation of the complement cascade may promote complement-mediated phagocytosis. C1q, MBL and cleavage fragments of C3/C4 can bind to several receptors expressed on macrophages (e.g. cC1qR (calreticulin), CR1, CR3, CR4) suggesting a potential clearance mechanism through this interaction (Mevorach D et al. 1998; Ogden CA et al. 2001). Apoptosis is also associated with an altered expression of complement regulators on the surface of apoptotic cells. CD46 (MCP) bound to the plasma membrane of a healthy cell protects it from complement-mediated attack by preventing deposition of C3b and C4b, and reduced expression of CD46 on dying cells may lead to enhanced opsonization (Elward K et al. 2005). Upregulation of CD55 (DAF) and CD59 on apoptotic cell surfaces may protect damaged cells against complement mediated lysis (Pedersen ED et al. 2007; Iborra A et al. 2003; Hensel F et al. 2001). In addition, fluid-phase complement regulators such as C4BP, CFH may also inhibit lysis of apoptotic cells by limiting complement activation (Trouw LA et al 2007; Braunschweig A and Jozsi M. 2011). Complement facilitates the clearance of immune complexes (IC) from the circulation (Chevalier J and Kazatchkine MD 1989; Nielsen CH et al. 1997). Erythrocytes bear clusters of complement receptor 1 (CR1 or CD35), which serves as an immune adherence receptor for C3 and/or C4 fragments deposited on IC that are shuttled to liver and spleen, where IC are transferred and processed by tissue macrophages through an Fc receptor-mediated process. Complement proteins are always present in the blood and a small percentage spontaneously activate. Inappropriate activation leads to host cell damage, so on healthy human cells any complement activation or amplification is strictly regulated by surface-bound regulators that accelerate decay of the convertases (CR1, CD55), act as a cofactor for the factor I (CFI)-mediated degradation of C3b and C4b (CR1, CD46), or prevent the formation of MAC (CD59). Soluble regulators such as C4BP, CFH and FHL1 recognize self surface pattern-like glycosaminoglycans and further impair activation. Complement components interact with other biological systems. Upon microbial infection complement acts in cooperation with Toll-like receptors (TLRs) to amplify innate host defense. Anaphylatoxin C5a binds C5a receptor (C5aR) resulting in a synergistic enhancement of the TLR and C5aR-mediated proinflammatory cytokine response to infection. This interplay is negatively modulated by co-ligation of TLR and the second C5a receptor, C5L2, suggesting the existence of complex immunomodulatory interactions (Kohl J 2006; Hajishengallis G and Lambris JD 2010). In addition to C5aR and C5L2, complement receptor 3 (CR3) facilitates TLR2 or TLR4 signaling pathways by promoting a recruitment of their sorting adaptor TIRAP (MAL) to the receptor complex (van Bruggen R et al. 2007; Kagan JC and Medzhitov R 2006). Complement may activate platelets or facilitate biochemical and morphological changes in the endothelium potentiating coagulation and contributing to homeostasis in response to injury (Oikonomopoulou K et al. 2012). The interplay of complement and coagulation also involves cleavage of C3 and C5 convertases by coagulation proteases, generating biologically active anaphylatoxins (Amara U et al. 2010). Complement is believed to link the innate response to both humoral and cell-mediated immunity (Toapanta FR and Ross TM 2006; Mongini PK et al. 1997). The majority of published data is based on experiments using mouse as a model organism. Further characterization of the influence of complement on B or T cell activation is required for the human system, since differences between murine models and the human system are not yet fully determined. Complement is also involved in regulation of mobilization and homing of hematopoietic stem/progenitor cells (HSPCs) from bone marrow to the circulation and peripheral tissue in order to accommodate blood cell replenishment (Reca R et al. 2006). Thus, the complement system orchestrates the host defense by sensing a danger signal and transmitting it into specific cellular responses while extensively communicating with associated biological pathways ranging from immunity and inflammation to homeostasis and development. Originally the larger fragment of Complement Factor 2 (C2) was designated C2a. However, complement scientists decided that the smaller of all C fragments should be designated with an 'a', the larger with a 'b', changing the nomenclature for C2. Recent literature may use the updated nomenclature and refer to the larger C2 fragment as C2b, and refer to the classical C3 convertase as C4bC2b. Throughout this pathway Reactome adheres to the original convention to agree with the current (Sep 2013) Uniprot names for C2 fragments. The complement cascade pathway is organised into the following sections: initial triggering, activation of C3 and C5, terminal pathway and regulation."
BMGC_PW0186,BMG_PW0500,"The classical complement pathway is one of the three biochemical pathways of the complement system. It is activated by antigen-bound antibodies. [GO:0006958, KEGG:map04610, PMID:11287977, Reactome:R-HSA-173623]","The complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation: the classical pathway, the lectin pathway, and the alternative pathway. All of these pathways generate a crucial enzymatic activity that, in turn, generates the effector molecules of complement. The main consequences of complement activation are the opsonization of pathogens, the recruitment of inflammatory and immunocompetent cells, and the direct killing of pathogens. Blood coagulation is another series of proenzyme-to-serine protease conversions, culminating the formation of thrombin, the enzyme responsible for the conversion of soluble fibrinogen to the insoluble fibrin clot. Protease-activated receptors, such as those activated by thrombin, are members of G protein-coupled receptors and function as a mediator of innate immunity. The kallikrein-kinin system is an endogenous metabolic cascade, triggering of which results in the release of vasoactive kinins (bradykinin-related peptides). Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning.","C1, the first component of complement is a complex containing three protein species, C1q, C1r, and C1s. C1q is assembled from six identical subunits each of which consists of three homologous chains (A, B, and C). These chains form a globular domain at the C-terminus, followed by the ""neck"" and a coil in the ""stalk."" The six subunits are held together by the collagenous stalk parts (giving rise to the comparison of C1q with a ""bunch of six tulips""). The stalks also interact with the [C1s:C1r:C1r:C1s] tetramer assembled in a linear chain. Binding of an antigen to an antibody of the IgM or IgG class induces a conformational change in the Fc domain of the antibody that allows it to bind to the C1q component of C1. C1 activation requires interaction with two separate Fc domains, so pentavalent IgM antibody is far more efficient at complement activation than IgG antibody. Antibody binding results in a conformational change in the C1r component of the C1 complex and a proteolytic cleavage of C1r, activating it. Active C1r then cleaves and activates the C1s component of the C1 complex (Muller-Eberhard 1988)."
BMGC_PW0187,BMG_PW0501,"The lectin pathway is one of the three biochemical pathways of the complement system. It is activated by microbial polysaccharides binding to circulating lectins. [GO:0001867, KEGG:map04610, PMID:11287977, Reactome:R-HSA-166662]","The complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation: the classical pathway, the lectin pathway, and the alternative pathway. All of these pathways generate a crucial enzymatic activity that, in turn, generates the effector molecules of complement. The main consequences of complement activation are the opsonization of pathogens, the recruitment of inflammatory and immunocompetent cells, and the direct killing of pathogens. Blood coagulation is another series of proenzyme-to-serine protease conversions, culminating the formation of thrombin, the enzyme responsible for the conversion of soluble fibrinogen to the insoluble fibrin clot. Protease-activated receptors, such as those activated by thrombin, are members of G protein-coupled receptors and function as a mediator of innate immunity. The kallikrein-kinin system is an endogenous metabolic cascade, triggering of which results in the release of vasoactive kinins (bradykinin-related peptides). Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning.","Activation of the lectin pathway (LP) is initiated by Mannose-binding lectin (MBL), the hetero-complex CL-LK formed from COLEC11 (Collectin liver 1, CL-L1) and COLEC10 (Collectin kidney 1, CL-K1), and the ficolins (FCN1, FCN2, FCN3). All are Ca-dependent (C-type) lectins that initiate the complement cascade after binding to specific carbohydrate patterns on the target cell surface. All form trimers and larger oligomers (Jensen et al. 2005, Dommett et al. 2006, Garlatti et al. 2010). MBL and ficolins circulate in plasma as complexes with homodimers of MBL-associated serine proteases (MASP) (Fujita et al. 2004, Hajela et al. 2002). MASP1, MASP2 and MASP3 have all been reported to mediate complement activation. Upon binding of human lectin to the target surface, the complex of lectin:MASP undergoes conformational changes that result in MASP cleavage and activation (Matsushita M et al. 2000, Fujita et al. 2004). Active MASP2 cleaves C4 to generate C4a and C4b. C4b binds to the target cell surface via its thioester bond, then binds circulating C2 (Law and Dodds 1997). Bound C2 is cleaved by MASP2 to yield the C3 convertase C4b:C2a. The active form of MASP1 was reported to cleave C2 in a manner similar to MASP2 (Matsushita et al. 2000, Chen & Wallis 2004). MASP1 can cleave proenzyme MASP2, leading to complement activation (Heja et al. 2012). MASP1 can also cleave fibrinogen to yield fibrinopeptide B, and activates factor XIII. MASP1 may have a role in removal of 'dead C3', i.e. C3(H2O) (Hajela et al. 2002). In addition to MASP1 to 3, two alternatively-slpiced forms of MASP1 (MAp44) and MASP2 (sMAP) have been implicated in complement cascade signaling (Takahashi et al. 1999, Degn et al. 2010). The functions of MASP3, sMAP and MAp44 in the lectin pathway remain to be clarified."
BMGC_PW0188,BMG_PW0502,"The alternative pathway is one of the three biochemical pathways of the complement system. Stable activation of the alternative pathway occurs on microbial cell surfaces. [GO:0006957, KEGG:map04610, PMID:11287977, Reactome:R-HSA-173736]","The complement system is a proteolytic cascade in blood plasma and a mediator of innate immunity, a nonspecific defense mechanism against pathogens. There are three pathways of complement activation: the classical pathway, the lectin pathway, and the alternative pathway. All of these pathways generate a crucial enzymatic activity that, in turn, generates the effector molecules of complement. The main consequences of complement activation are the opsonization of pathogens, the recruitment of inflammatory and immunocompetent cells, and the direct killing of pathogens. Blood coagulation is another series of proenzyme-to-serine protease conversions, culminating the formation of thrombin, the enzyme responsible for the conversion of soluble fibrinogen to the insoluble fibrin clot. Protease-activated receptors, such as those activated by thrombin, are members of G protein-coupled receptors and function as a mediator of innate immunity. The kallikrein-kinin system is an endogenous metabolic cascade, triggering of which results in the release of vasoactive kinins (bradykinin-related peptides). Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning.","The proteins participating in alternative pathway activation are C3 (and C3b), the factors B, D, and properdin. In the first place, alternative pathway activation is a positive feedback mechanism to increase C3b. When C3b binds covalently to sugars on a cell surface, it can become protected. Then Factor B binds to C3b. In the presence of Factor D, bound Factor B is cleaved to Ba and Bb. Bb contains the active site for a C3 convertase. Properdin then binds to C3bBb to stabilize the C3bBb convertase on cell surface leading to cleavage of C3. Finally, a C3bBb3b complex forms and this is a C5 convertase."
BMGC_PW0189,BMG_PW0505,"The pathway involving the attachment of platelets to one another and leading to the formation of a thrombus. Platelet attachment can be induced by a variety of agents. [GO:0070527, OneLook:www.onelook.com, Reactome:R-HSA-76009]",,"The tethering of platelets to the site of vascular injury is the first step in the formation of a platelet thrombus. Firm adhesion of these tethered platelets, as well as the additional recruitment of others onto their surface leads to the formation of large platelet aggregates. The formation of a thrombus is strictly dependent on the formation of interplatelet bonds."
BMGC_PW0190,BMG_PW0509,Signaling by interleukin family members plays various roles in the immune response. [Reactome:R-HSA-449147],,"Interleukins are low molecular weight proteins that bind to cell surface receptors and act in an autocrine and/or paracrine fashion. They were first identified as factors produced by leukocytes but are now known to be produced by many other cells throughout the body. They have pleiotropic effects on cells which bind them, impacting processes such as tissue growth and repair, hematopoietic homeostasis, and multiple levels of the host defense against pathogens where they are an essential part of the immune system."
BMGC_PW0191,BMG_PW0511,"The interleukin-6 family includes several members involved in a wide range of biological processes such as immune regulation, inflammation, hematopoiesis and oncogenesis. All members share a common signal transducer, gp130, which activates Jak-Stat and Raf/Mek/Erk signaling pathways. [PMID:20410258, PMID:21715184, Reactome:R-HSA-6783589]",,"The interleukin-6 (IL6) family of cytokines includes IL6, IL11, IL27, leukemia inhibitory factor (LIF), oncostatin M (OSM), ciliary neurotrophic factor (CNTF), cardiotrophin 1 and 2 (CT-1) and cardiotrophin-like cytokine (CLC) (Heinrich et al. 2003, Pflanz et al. 2002). The latest addition to this family is IL31, discovered in 2004 (Dillon et al. 2004). The family is defined largely by the shared use of the common signal transducing receptor Interleukin-6 receptor subunit beta (IL6ST, gp130). The IL31 receptor uniquely does not include this subunit, instead it uses the related IL31RA. The members of the IL6 family share very low sequence homology but are structurally highly related, forming anti-parallel four-helix bundles with a characteristic “up-up-down-down” topology (Rozwarski et al. 1994, Cornelissen et al. 2012). Although each member of the IL6 family signals through a distinct receptor complex, their underlying signaling mechanisms are similar. Assembly of the receptor complex is followed by activation of receptor-associated Janus kinases (JAKs), believed to be constitutively associated with the receptor subunits.Activation of JAKs initiates downstream cytoplasmic signaling cascades that involve recruitment and phosphorylation of transcription factors of the Signal transducer and activator of transcription (STAT) family, which dimerize and translocate to the nucleus where they bind enhancer elements of target genes leading to transcriptional activation (Nakashima & Taga 1998). Negative regulators of IL6 signaling include Suppressor of cytokine signals (SOCS) family members and PTPN11 (SHP-2). IL6 is a pleiotropic cytokine with roles in processes including immune regulation, hematopoiesis, inflammation, oncogenesis, metabolic control and sleep. IL6 and IL11 bind their corresponding specific receptors IL6R and IL11R respectively, resulting in dimeric complexes that subsequently associate with IL6ST, leading to IL6ST homodimer formation (in a hexameric or higher order complex) and signal initiation. IL6R alpha exists in transmembrane and soluble forms. The transmembrane form is mainly expressed by hepatocytes, neutrophils, monocytes/macrophages, and some lymphocytes. Soluble forms of IL6R (sIL6R) are also expressed by these cells. Two major mechanisms for the production of sIL6R have been proposed. Alternative splicing generates a transcript lacking the transmembrane domain by using splicing donor and acceptor sites that flank the transmembrane domain coding region. This also introduces a frameshift leading to the incorporation of 10 additional amino acids at the C terminus of sIL6R.A second mechanism for the generation of sIL6R is the proteolytic cleavage or 'shedding' of membrane-bound IL-6R. Two proteases ADAM10 and ADAM17 are thought to contribute to this (Briso et al. 2008). sIL6R can bind IL6 and stimulate cells that express gp130 but not IL6R alpha, a process that is termed trans-signaling. This explains why many cells, including hematopoietic progenitor cells, neuronal cells, endothelial cells, smooth muscle cells, and embryonic stem cells, do not respond to IL6 alone, but show a remarkable response to IL6/sIL6R. It is clear that the trans-signaling pathway is responsible for the pro-inflammatory activities of IL6 whereas the membrane bound receptor governs regenerative and anti-inflammatory IL6 activities LIF, CNTF, OSM, CTF1, CRLF1 and CLCF1 signal via IL6ST:LIFR heterodimeric receptor complexes (Taga & Kishimoto 1997, Mousa & Bakhiet 2013). OSM signals via a receptor complex consisting of IL6ST and OSMR. These cytokines play important roles in the regulation of complex cellular processes such as gene activation, proliferation and differentiation (Heinrich et al. 1998). Antibodies have been developed to inhibit IL6 activity for the treatment of inflammatory diseases (Kopf et al. 2010)."
BMGC_PW0192,BMG_PW0512,"Interleukin-10 signaling is involved in various immunomodulatory functions. It promotes the release of immune mediators and antigen presentation, exerting important anti-inflammatory effects that may primarily characterize this family member. Signaling by Il-10 and the other members of the family activate the intracellular Jak-Stat cascade. [GO:0140105, PMID:20454917, PMID:21115385, Reactome:R-HSA-6783783]",,"Interleukin-10 (IL10) was originally described as a factor named cytokine synthesis inhibitory factor that inhibited T-helper (Th) 1 activation and Th1 cytokine production (Fiorentino et al. 1989). It was found to be expressed by a variety of cell types including macrophages, dendritic cell subsets, B cells, several T-cell subpopulations including Th2 and T-regulatory cells (Tregs) and Natural Killer (NK) cells (Moore et al. 2001). It is now recognized that the biological effects of IL10 are directed at antigen-presenting cells (APCs) such as macrophages and dendritic cells (DCs), its effects on T-cell development and differentiation are largely indirect via inhibition of macrophage/dendritic cell activation and maturation (Pestka et al. 2004, Mocellin et al. 2004). T cells are thought to be the main source of IL10 (Hedrich & Bream 2010). IL10 inhibits a broad spectrum of activated macrophage/monocyte functions including monokine synthesis, NO production, and expression of class II MHC and costimulatory molecules such as IL12 and CD80/CD86 (de Waal Malefyt et al. 1991, Gazzinelli et al. 1992). Studies with recombinant cytokine and neutralizing antibodies revealed pleiotropic activities of IL10 on B, T, and mast cells (de Waal Malefyt et al. 1993, Rousset et al. 1992, Thompson-Snipes et al. 1991) and provided evidence for the in vivo significance of IL10 activities (Ishida et al. 1992, 1993). IL10 antagonizes the expression of MHC class II and the co-stimulatory molecules CD80/CD86 as well as the pro-inflammatory cytokines IL1Beta, IL6, IL8, TNFalpha and especially IL12 (Fiorentino et al. 1991, D'Andrea et al. 1993). The biological role of IL10 is not limited to inactivation of APCs, it also enhances B cell, granulocyte, mast cell, and keratinocyte growth/differentiation, as well as NK-cell and CD8+ cytotoxic T-cell activation (Moore et al. 2001, Hedrich & Bream 2010). IL10 also enhances NK-cell proliferation and/or production of IFN-gamma (Cai et al. 1999). IL10-deficient mice exhibited inflammatory bowel disease (IBD) and other exaggerated inflammatory responses (Kuhn et al. 1993, Berg et al. 1995) indicating a critical role for IL10 in limiting inflammatory responses. Dysregulation of IL10 is linked with susceptibility to numerous infectious and autoimmune diseases in humans and mouse models (Hedrich & Bream 2010). IL10 signaling is initiated by binding of homodimeric IL10 to the extracellular domains of two adjoining IL10RA molecules. This tetramer then binds two IL10RB chains. IL10RB cannot bind to IL10 unless bound to IL10RA (Ding et al. 2001, Yoon et al. 2006); binding of IL10 to IL10RA without the co-presence of IL10RB fails to initiate signal transduction (Kotenko et al. 1997). IL10 binding activates the receptor-associated Janus tyrosine kinases, JAK1 and TYK2, which are constitutively bound to IL10R1 and IL10R2 respectively. In the classic model of receptor activation assembly of the receptor complex is believed to enable JAK1/TYK2 to phosphorylate and activate each other. Alternatively the binding of IL10 may cause conformational changes that allow the pseudokinase inhibitory domain of one JAK kinase to move away from the kinase domain of the other JAK within the receptor dimer-JAK complex, allowing the two kinase domains to interact and trans-activate (Waters & Brooks 2015). The activated JAK kinases phosphorylate the intracellular domains of the IL10R1 chains on specific tyrosine residues. These phosphorylated tyrosine residues and their flanking peptide sequences serve as temporary docking sites for the latent, cytosolic, transcription factor, STAT3. STAT3 transiently docks on the IL10R1 chain via its SH2 domain, and is in turn tyrosine phosphorylated by the receptor-associated JAKs. Once activated, it dissociates from the receptor, dimerizes with other STAT3 molecules, and translocates to the nucleus where it binds with high affinity to STAT-binding elements (SBEs) in the promoters of IL-10-inducible genes (Donnelly et al. 1999)."
BMGC_PW0193,BMG_PW0513,"Interleukin-6 signaling is involved in a wide range of biological processes such as immune regulation, inflammation, hematopoiesis and oncogenesis. A signal transducer common to all family members, gp130 activates Jak-Stat and Raf/Mek/Erk signaling pathways. [GO:0070102, PID:200146, PMID:20303867, PMID:20410258, PMID:21715184, Reactome:R-HSA-1059683]",,"Interleukin-6 (IL-6) is a pleiotropic cytokine with roles in processes including immune regulation, hematopoiesis, inflammation, oncogenesis, metabolic control and sleep. It is the founding member of a family of IL-6-related cytokines such as IL-11, IL-27 leukemia inhibitory factor (LIF), cilliary neurotrophic factor (CNTF) and oncostatin M. The IL-6 receptor (IL6R) consists of an alpha subunit that specifically binds IL-6 and a beta subunit, IL6RB or gp130, which is the signaling component of all the receptors for cytokines related to IL-6. IL6R alpha exists in transmembrane and soluble forms. The transmembrane form is mainly expressed by hepatocytes, neutrophils, monocytes/macrophages, and some lymphocytes. Soluble forms of IL6R (sIL6R) are also expressed by these cells. Two major mechanisms for the production of sIL6R have been proposed. Alternative splicing generates a transcript lacking the transmembrane domain by using splicing donor and acceptor sites that flank the transmembrane domain coding region. This also introduces a frameshift leading to the incorporation of 10 additional amino acids at the C terminus of sIL6R.A second mechanism for the generation of sIL6R is the proteolytic cleavage or 'shedding' of membrane-bound IL-6R. Two proteases ADAM10 and ADAM17 are thought to contribute to this (Briso et al. 2008). sIL6R can bind IL6 and stimulate cells that express gp130 but not IL6R alpha, a process that is termed trans-signaling. This explains why many cells, including hematopoietic progenitor cells, neuronal cells, endothelial cells, smooth muscle cells, and embryonic stem cells, do not respond to IL6 alone, but show a remarkable response to IL6/sIL6R. It is clear that the trans-signaling pathway is responsible for the pro-inflammatory activities of IL-6 whereas the membrane bound receptor governs regenerative and anti-inflammatory IL-6 activities IL6R signal transduction is mediated by two pathways:the JAK-STAT (Janus family tyrosine kinase-signal transducer and activator of transcription) pathway and the Ras-MAPK (mitogen-activated protein kinase) pathway. Negative regulators of IL-6 signaling include SOCS (suppressor of cytokine signals) and SHP2. Within the last few years different antibodies have been developed to inhibit IL-6 activity, and the first such antibodies have been introduced into the clinic for the treatment of inflammatory diseases (Kopf et al. 2010)."
BMGC_PW0194,BMG_PW0519,"Those enzymatic reactions involved in the biosynthesis of flavonoids - a class of plant secondary metabolites generally known for their antioxidant activity. [GO:0009813, KEGG:map00941, OneLook:www.onelook.com]",,
BMGC_PW0195,BMG_PW0520,"Those enzymatic reactions involved in the synthesis, utilization or degradation of linoleic acid - an unsaturated omega-6 fatty acid. Linoleic acid is an essential fatty acid that humans and other animals cannot synthesize and must obtain from diet. [GO:0043651, http://www.onelook.com OneLook, KEGG:map00591, Reactome:R-HSA-2046105, SMP:00018]",,"Linoleic acid (LA, 18:2(n-6)) is an omega-6 fatty acid obtained through diet, mainly from vegetable oils. Omega-6 fatty acids helps stimulate skin and hair growth, maintain bone health, regulate metabolism, and maintain the reproductive system. All the desaturation and elongation steps occur in the endoplasmic reticulum (ER) except for the final step which requires translocation to peroxisomes for partial beta-oxidation. The linoleic acid pathway involves the following steps: 18:2(n-6)-->18:3(n-6)--> 20:3(n-6)-->20:4(n-6)-->22:4(n-6)-->24:4(n-6)-->24:5(n-6)-->22:5(n-6). Two desaturation enzymes are involved in this process: delta-6 desaturase which converts 18:2(n-6) to 18:3 (n-6) and 24:4(n-6) to 24:5(n-6) respectively, and delta-5 desaturase which converts 20:3(n-6) to 20:4(n-6). (Sprecher 2002)."
BMGC_PW0196,BMG_PW0521,"Those metabolic reactions involved in the biosynthesis of heparan sulfate. Heparan sulfate is a glycosaminoglycan occurring in the cell membrane of most cells. It consists of repeating disaccharide units in specific linkage, each composed of a glucosamine residue linked to a uronic acid, either glucuronic acid or L-iduronic acid, which may be sulfated. [GO:0030210, KEGG:map00534, OneLook:www.onelook.com, Reactome:R-HSA-2022928]","Heparan sulfate (HS) and heparin (Hep) are glycosaminoglycans with repeating disaccharide units that consist of alternating residues of alpha-D-glucosamine (GlcN) and uronic acid, the latter being either beta-D-glucuronic acid (GlcA) or alpha-L-iduronic acid (IdoA). In these sugar residues, sulfation modification may be performed at various positions. Structural studies show that Hep possesses a higher degree of sulfation than HS. The biosynthesis of HS/Hep occurs with the addition of the first GlcNAc residue by EXTL3 glycosyltransferase after completion of tetrasaccharide linkage region attached to serine residue of a core protein. The chain polymeraization is then catalyzed by EXT1 and EXT2 transferases. As the chain polymerizes, HS/Hep undergoes a series of modification reactions including N-deacetylation, N-sulfation, epimerization, and subsequently O-sulfation. As final products of biosynthesis, HS is present in the form of hepran sulfate proteoglycan (HSPG) whereas Hep exists as a sugar chain without a core protein. The proteoglycan families with HS, as well as CS (chondroitin sulfate), DS (dermatan sulfate), and KS (keratan sulfate), are composed of two main types depending on the subcellular locations: cell membrane and extracellular matrix [BR:00535]. HS/Hep has been shown to bind to a variety of molecules, such as growth factors, chemokines, morphogens, and extracellular matrix components [BR:00536].","Heparan sulfate (HS) and heparin (sometimes collectively called HS-GAG) consist of the disaccharide unit GlcNAc-GlcA (N-acetylglucosamine-glucuronic acid) connected by a beta1,4 linkage. Heparin is exclusively made in mast cells whereas HS is made by virtually every type of cell in the body. As the chain length increases, the polysaccharides can undergo modifcations such as epimerisation of glucuronic acid to iduronic acid and deacetylation and sulfation of GlcNAc to form sulfated glucosamine (Stringer & Gallagher 1997, Sasisekharan & Venkataraman 2000)."
BMGC_PW0197,BMG_PW0529,"Those metabolic reactions leading to the biosynthesis of glycogen, a highly branched polysaccharide. Glycogen is the storage form of glucose in the cell; it represents an energy reserve that can be mobilized when and where there is a need for glucose. [GO:0005978, OneLook:www.onelook.com, Reactome:R-HSA-3322077]",,"Glycogen, a highly branched glucose polymer, is formed and broken down in most human tissues, but is most abundant in liver and muscle, where it serves as a major stored fuel. Glycogen metabolism has been studied in most detail in muscle, although considerable experimental data are available concerning these reactions in liver as well. Glycogen metabolism in other tissues has not been studied as extensively, and is thought to resemble the muscle process. Glycogen synthesis involves five reactions. The first two, conversion of glucose 6-phosphate to glucose 1-phosphate and synthesis of UDP-glucose from glucose 1-phosphate and UTP, are shared with several other pathways. The next three reactions, the auto-catalyzed synthesis of a glucose oligomer on glycogenin, the linear extension of the glucose oligomer catalyzed by glycogen synthase, and the formation of branches catalyzed by glycogen branching enzyme, are unique to glycogen synthesis. Repetition of the last two reactions generates large, extensively branched glycogen polymers. The catalysis of glycogenin glucosylation and oligoglucose chain extension by distinct isozymes in liver and nonhepatic tissues allows them to be regulated independently (Agius 2008; Bollen et al. 1998; Roach et al. 2012)."
BMGC_PW0198,BMG_PW0531,"Those metabolic reactions involved in the breakdown of glycogen to glucose-6-phosphate. Glucose-6-phosphate can then be dephosphorylated to glucose or it can be utilized via glycolysis for energy production; an alternative pathway of G6P utilization is the oxidative phase of the pentose phosphate shunt. A small percentage of glucose-6-phosphate can be converted to hexosamines. [GO:0005980, OneLook:www.onelook.com, Reactome:R-HSA-70221]",,"Cytosolic glycogen breakdown occurs via the same chemical steps in all tissues but is separately regulated via tissue specific isozymes and signaling pathways that enable distinct physiological fates for liver glycogen and that in other tissues. Glycogen phosphorylase, which can be activated by phosphorylase kinase, catalyzes the removal of glucose residues as glucose 1-phosphate from the ends of glycogen branches. The final four residues of each branch are removed in two steps catalyzed by debranching enzyme, and further glycogen phosphorylase activity completes the process of glycogen breakdown. The figure shows the actions of phosphorylase and debranching enzyme. The first glucose residue in each branch is released as free glucose; all other residues are released as glucose 1-phosphate. The latter molecule can be converted to glucose 6-phosphate in a step shared with other pathways (Villar-Palasi and Larner 1970; Hers 1976). Glycogen can also be taken up into lysosomes, where it is normally broken done by the action of a single enzyme, lysosomal alpha-glucosidase (GAA). Enzymes in liver generate 1,5-anhydro-D-fructose from glycogen, which in turn can be reduced to 1,5-anhydro-D-glucitol, a sequence of events that may represent a novel minor pathway for glycogen breakdown (Kametani et al. 1996)."
BMGC_PW0199,BMG_PW0545,"The nonsense-mediated decay pathway (NMD) degrades mRNA that contains a premature translation termination codon (PTC) and is one of the best characterized systems in eukaryotes. [GO:0000184, PMID:15933735, PMID:17010613, PMID:22664987, Reactome:R-HSA-927802]",,"The Nonsense-Mediated Decay (NMD) pathway activates the destruction of mRNAs containing premature termination codons (PTCs) (reviewed in Isken and Maquat 2007, Chang et al. 2007, Behm-Ansmant et al. 2007, Neu-Yilik and Kulozik 2008, Rebbapragada and Lykke-Andersen 2009, Bhuvanagiri et al. 2010, Nicholson et al. 2010, Durand and Lykke-Andersen 2011). In mammalian cells a termination codon can be recognized as premature if it precedes an exon-exon junction by at least 50-55 nucleotides or if it is followed by an abnormal 3' untranslated region (UTR). While length of the UTR may play a part, the qualifications for being ""abnormal"" have not been fully elucidated. Also, some termination codons preceding exon junctions are not degraded by NMD so the criteria for triggering NMD are not yet fully known (reviewed in Rebbapragada and Lykke-Andersen 2009). While about 30% of disease-associated mutations in humans activate NMD, about 10% of normal human transcripts are also degraded by NMD (reviewed in Stalder and Muhlemann 2008, Neu-Yilik and Kulozik 2008, Bhuvanagiri et al. 2010, Nicholson et al. 2010). Thus NMD is a normal physiological process controlling mRNA stability in unmutated cells. Exon junction complexes (EJCs) are deposited on an mRNA during splicing in the nucleus and are displaced by ribosomes during the first round of translation. When a ribosome terminates translation the A site encounters the termination codon and the eRF1 factor enters the empty A site and recruits eRF3. Normally, eRF1 cleaves the translated polypeptide from the tRNA in the P site and eRF3 interacts with Polyadenylate-binding protein (PABP) bound to the polyadenylated tail of the mRNA. During activation of NMD eRF3 interacts with UPF1 which is contained in a complex with SMG1, SMG8, and SMG9. NMD can arbitrarily be divided into EJC-enhanced and EJC-independent pathways. In EJC-enhanced NMD, an exon junction is located downstream of the PTC and the EJC remains on the mRNA after termination of the pioneer round of translation. The core EJC is associated with UPF2 and UPF3, which interact with UPF1 and stimulate NMD. Once bound near the PTC, UPF1 is phosphorylated by SMG1. The phosphorylation is the rate-limiting step in NMD and causes UPF1 to recruit either SMG6, which is an endoribonuclease, or SMG5 and SMG7, which recruit ribonucleases. SMG6 and SMG5:SMG7 recruit phosphatase PP2A to dephosphorylate UPF1 and allow further rounds of degradation. How EJC-independent NMD is activated remains enigmatic but may involve competition between PABP and UPF1 for eRF3."
BMGC_PW0200,BMG_PW0549,"Those metabolic reactions involved in the biosynthesis of brassinosteroids or brassins, a group of plant hormones released in response to low oxygen and sugar, or to root stresses. [GO:0016132, http://www.onelook.com OneLook, KEGG:map00905]",,
BMGC_PW0201,BMG_PW0559,"The growth hormone signaling pathway is an important regulator of postnatal development. However, despite many years of research, the molecular mechanisms underlying its many actions are incompletely understood. It is believed that its actions involve direct and indirect routes. An example of the latter is the role the pathway plays in stimulating the production of insulin-like growth factor. [GO:0060396, PMID:19407495, PMID:8853443, Reactome:R-HSA-982772]",,"Growth hormone (Somatotropin or GH) is a key factor in determining lean body mass, stimulating the growth and metabolism of muscle, bone and cartilage cells, while reducing body fat. It has many other roles; it acts to regulate cell growth, differentiation, apoptosis, and reorganisation of the cytoskeleton, affecting diverse processes such as cardiac function, immune function, brain function, and aging. GH also has insulin-like effects such as stimulating amino acid transport, protein synthesis, glucose transport, and lipogenesis. The growth hormone receptor (GHR) is a a member of the cytokine receptor family. When the dimeric receptor binds GH it undergoes a conformational change which leads to phosphorylation of key tyrosine residues in its cytoplasmic domains and activation of associated tyrosine kinase JAK2. This leads to recruitment of signaling molecules such as STAT5 and Src family kinases such as Lyn leading to ERK activation. The signal is attenuated by association of Suppressor of Cytokine Signaling (SOCS) proteins and SHP phosphatases which bind to or dephosphorylate specific phosphorylated tyrosines on GHR/JAK. The availability of GHR on the cell surface is regulated by at least two processes; internalization and cleavage from the suface by metalloproteases."
BMGC_PW0202,BMG_PW0572,"Those pathways that mediate the transport of sugars across the cell membrane. Transport of glucose, one of the major energy sources in the cell, is an important aspect of the sugar transport pathway. [http://www.ncbi.nlm.nih.gov/ Pubmed, Reactome:R-HSA-189200]",,"Two gene families are responsible for glucose transport in humans. SLC2 (encoding GLUTs) and SLC5 (encoding SGLTs) families mediate glucose absorption in the small intestine, glucose reabsorption in the kidney, glucose uptake by the brain across the blood-brain barrier and glucose release by all cells in the body. Glucose is taken up from interstitial fluid by a passive, facilitative transport driven by the diffusion gradient of glucose (and other sugars) across the plasma membrane. This process is mediated by a family of Na+-independent, facilitative glucose transporters (GLUTs) encoded by the SLC2A gene family (Zhao & Keating 2007; Wood & Trayhurn 2003). There are 14 members belonging to this family (GLUT1-12, 14 and HMIT (H+/myo-inositol symporter)). The GLUT family can be subdivided into three subclasses (I-III) based on sequence similarity and characteristic sequence motifs (Joost & Thorens 2001). Hexoses, notably fructose, glucose, and galactose, generated in the lumen of the small intestine by breakdown of dietary carbohydrate are taken up by enterocytes lining the microvilli of the small intestine and released from them into the blood. Uptake into enterocytes is mediated by two transporters localized on the lumenal surfaces of the cells, SGLT1 (glucose and galactose, together with sodium ions) and GLUT5 (fructose). GLUT2, localized on the basolateral surfaces of enterocytes, mediates the release of these hexoses into the blood (Wright et al. 2004). GLUT2 may also play a role in hexose uptake from the gut lumen into enterocytes when the lumenal content of monosaccharides is very high (Kellet & Brot-Laroche 2005) and GLUT5 mediates fructose uptake from the blood into cells of the body, notably hepatocytes. Cells take up glucose by facilitated diffusion, via glucose transporters (GLUTs) associated with the plasma membrane, a reversible reaction. Four tissue-specific GLUT isoforms are known. Glucose in the cytosol is phosphorylated by tissue-specific kinases to yield glucose 6-phosphate, which cannot cross the plasma membrane because of its negative charge. In the liver, this reaction is catalyzed by glucokinase which has a low affinity for glucose (Km about 10 mM) but is not inhibited by glucose 6-phosphate. In other tissues, this reaction is catalyzed by isoforms of hexokinase. Hexokinases are feedback-inhibited by glucose 6-phosphate and have a high affinity for glucose (Km about 0.1 mM). Liver cells can thus accumulate large amounts of glucose 6-phosphate but only when blood glucose concentrations are high, while most other tissues can take up glucose even when blood glucose concentrations are low but cannot accumulate much intracellular glucose 6-phosphate. These differences are consistent with the view that that the liver functions to buffer blood glucose concentrations, while most other tissues take up glucose to meet immediate metabolic needs. Glucose 6-phosphatase, expressed in liver and kidney, allows glucose 6-phosphate generated by gluconeogenesis (both tissues) and glycogen breakdown (liver) to leave the cell. The absence of glucose 6-phosphatase from other tissues makes glucose uptake by these tissues essentially irreversible, consistent with the view that cells in these tissues take up glucose for local metabolic use. Class II facilitative transporters consist of GLUT5, 7, 9 and 11 (Zhao & Keating 2007, Wood & Trayhurn 2003)."
BMGC_PW0203,BMG_PW0575,"Scatter factor/hepatocyte growth factor signaling impacts on various biological processes such as proliferation and survival, morphogenesis and motility. SF/HGF and its receptor c-Met have also been implicated in tumor growth and angiogenesis. [GO:0048012, PMID:16212809, PMID:16778093, PMID:18175071, Reactome:R-HSA-6806834]",,"MET is a receptor tyrosine kinase (RTK) (Cooper et al. 1984, Park et al. 1984) activated by binding to its ligand, Hepatocyte growth factor/Scatter factor (HGF/SF) (Bottaro et al. 1991, Naldini et al. 1991). Similar to other related RTKs, such as EGFR, ligand binding induces MET dimerization and trans-autophosphorylation, resulting in the active MET receptor complex (Ferracini et al. 1991, Longati et al. 1994, Rodrigues and Park 1994, Kirchhofer et al. 2004, Stamos et al. 2004, Hays and Watowich 2004). Phosphorylated tyrosines in the cytoplasmic tail of MET serve as docking sites for binding of adapter proteins, such as GRB2, SHC1 and GAB1, which trigger signal transduction cascades that activate PI3K/AKT, RAS, STAT3, PTK2, RAC1 and RAP1 signaling (Ponzetto et al. 1994, Pelicci et al. 1995, Weidner et al. 1995, Besser et al. 1997, Shen and Novak 1997, Beviglia and Kramer 1999, Rodrigues et al. 2000, Sakkab et al. 2000, Schaeper et al. 2000, Lamorte et al. 2002, Wang et al. 2002, Chen and Chen 2006, Palamidessi et al. 2008, Chen et al. 2011, Murray et al. 2014). Activation of PLC gamma 1 (PLCG1) signaling by MET remains unclear. It has been reported that PLCG1 can bind to MET directly (Ponzetto et al. 1994) or be recruited by phosphorylated GAB1 (Gual et al. 2000). Tyrosine residue Y307 of GAB1 that serves as docking sites for PLCG1 may be phosphorylated either by activated MET (Watanabe et al. 2006) or SRC (Chan et al. 2010). Another PCLG1 docking site on GAB1, tyrosine residue Y373, was reported as the SRC target, while the kinase for the main PLCG1 docking site, Y407 of GAB1, is not known (Chan et al. 2010). Signaling by MET promotes cell growth, cell survival and motility, which are essential for embryonic development (Weidner et al. 1993, Schmidt et al. 1995, Uehara et al. 1995, Bladt et al. 1995, Maina et al. 1997, Maina et al. 2001, Helmbacher et al. 2003) and tissue regeneration (Huh et al. 2004, Borowiak et al. 2004, Liu 2004, Chmielowiec et al. 2007). MET signaling is frequently aberrantly activated in cancer, through MET overexpression or activating MET mutations (Schmidt et al. 1997, Pennacchietti et al. 2003, Smolen et al. 2006, Bertotti et al. 2009). Considerable progress has recently been made in the development of HGF-MET inhibitors in cancer therapy. These include inhibitors of HGF activators, HGF inhibitors and MET antagonists, which are protein therapeutics that act outside the cell. Kinase inhibitors function inside the cell and have constituted the largest effort towards MET-based therapeutics (Gherardi et al. 2012). Pathogenic bacteria of the species Listeria monocytogenes, exploit MET receptor as an entryway to host cells (Shen et al. 2000, Veiga and Cossart 2005, Neimann et al. 2007). For review of MET signaling, please refer to Birchmeier et al. 2003, Trusolino et al. 2010, Gherardi et al. 2012, Petrini 2015."
BMGC_PW0204,BMG_PW0588,"The uptake and efflux routes of iron transport. Several systems mediate uptake of recycled and dietary iron. One system is involved in the efflux. [GO:0006826, PMID:25661197, PMID:26437604, Reactome:R-HSA-917937]",,"The transport of iron between cells is mediated by transferrin. However, iron can also enter and leave cells not only by itself, but also in the form of heme and siderophores. When entering the cell via the main path (by transferrin endocytosis), its goal is not the (still elusive) chelated iron pool in the cytosol nor the lysosomes but the mitochondria, where heme is synthesized and iron-sulfur clusters are assembled (Kurz et al,2008, Hower et al 2009, Richardson et al 2010)."
BMGC_PW0205,BMG_PW0592,"Phosphatidylinositol kinases represent a family of lipid kinases that phosphorylate the 3' position of the inositol ring in target substrates. They are grouped into three classes: class I, further subdivided into subclass A and B, class II and class III. By far the best known and characterized is class I, particularly IA that signals downstream of receptor tyrosine kinases and engages the Akt family of kinases. [GO:0014065, KEGG:04070, PMID:16847462, PMID:17052169, PMID:17641274, Reactome:R-HSA-109704]",,The PI3K (Phosphatidlyinositol-3-kinase) - AKT signaling pathway stimulates cell growth and survival.
BMGC_PW0206,BMG_PW0594,"The non-canonical Wnt signaling pathway groups the various Wnt signaling routes that are beta-catenin-independent. [GO:0035567, PID:200020, PMID:16019432, PMID:18432252, Reactome:R-HSA-3858494]",,"Humans and mice have 19 identified WNT proteins that were originally classified as either 'canonical' or 'non-canonical' depending upon whether they were able to transform the mouse mammary epithelial cell line C57MG and to induce secondary axis formation in Xenopus (Wong et al, 1994; Du et al, 1995). So-called canonical WNTs, including Wnt1, 3, 3a and 7, initiate signaling pathways that destabilize the destruction complex and allow beta-catenin to accumulate and translocate to the nucleus where it promotes transcription (reviewed in Saito-Diaz et al, 2013). Non-canonical WNTs, including Wnt 2, 4, 5a, 5b, 6, 7b, and Wnt11 activate beta-catenin-independent responses that regulate many aspects of morphogenesis and development, often by impinging on the cytoskeleton (reviewed in van Amerongen, 2012). Two of the main beta-catenin-independent pathways are the Planar Cell Polarity (PCP) pathway, which controls the establishment of polarity in the plane of a field of cells, and the WNT/Ca2+ pathway, which promotes the release of intracellular calcium and regulates numerous downstream effectors (reviewed in Gao, 2012; De, 2011)."
BMGC_PW0207,BMG_PW0600,"The Erk5 pathway, also known as the big MAP kinase, is activated by various stresses but not by inflammatory cytokines. In HeLa and PC12 cells, the pathway can be activated by growth factors. [GO:0070375, KEGG:map04010, PMID:17229475, PMID:17306385, Reactome:R-HSA-198765]","The mitogen-activated protein kinase (MAPK) cascade is a highly conserved module that is involved in various cellular functions, including cell proliferation, differentiation and migration. Mammals express at least four distinctly regulated groups of MAPKs, extracellular signal-related kinases (ERK)-1/2, Jun amino-terminal kinases (JNK1/2/3), p38 proteins (p38alpha/beta/gamma/delta) and ERK5, that are activated by specific MAPKKs: MEK1/2 for ERK1/2, MKK3/6 for the p38, MKK4/7 (JNKK1/2) for the JNKs, and MEK5 for ERK5. Each MAPKK, however, can be activated by more than one MAPKKK, increasing the complexity and diversity of MAPK signalling. Presumably each MAPKKK confers responsiveness to distinct stimuli. For example, activation of ERK1/2 by growth factors depends on the MAPKKK c-Raf, but other MAPKKKs may activate ERK1/2 in response to pro-inflammatory stimuli.","The location of neurotrophin stimulation appears to determine the nature of the transcriptional response through differential uses of individual MAP kinases. The ERK5 pathway has a unique function in retrograde signalling; in contrast, ERK1/2, which mediate nuclear responses following direct cell body stimulation, does not transmit a retrograde signal. Following neurotrophin stimulation of distal axons, phosphorylated TRK receptors are endocytosed and transported to the cell bodies, where MEK5 phosphorylates ERK5, leading to ERK5 nuclear translocation, phosphorylation of transcription factors, and neuronal survival. In contrast, neurotrophin stimulation of the cell bodies causes concurrent activation and nuclear transport of ERK1/2 as well as ERK5. Several distinctive features of the ERK5 pathway might be important for retrograde signalling. The ERK5 cascade does not depend on activation of the G-protein RAS. Instead, this pathway may use other G-proteins such as RAP that are associated with vesicles, or may not require any G-protein intermediate. Another distinctive feature is that the MEK5 isoform, which is expressed in the nervous system, exhibits a punctate staining pattern, suggesting a vesicular localization. ERK5 itself significantly differs from ERK1/2, and its substrate specificity also differs from ERK1/2. For instance, ERK5 directly activates transcription factors, including MEF2, that are not phosphorylated by ERK1/2. Conversely, ERK1/2, but not ERK5, activate transcription factors such as ELK1 and MITF."
BMGC_PW0208,BMG_PW0606,"Prostate cancer is a frequent form of cancer in men over the age of fifty. It is usually asymptomatic but when in an advanced stage, it may spread to other parts of the body, causing symptoms others than those sometimes observed. Several susceptibility as well as defective genes have been identified. [KEGG:map05215, PMID:12878745, PMID:14752525, PMID:15149739]","Prostate cancer constitutes a major health problem in Western countries. It is the most frequently diagnosed cancer among men and the second leading cause of male cancer deaths. The identification of key molecular alterations in prostate-cancer cells implicates carcinogen defenses (GSTP1), growth-factor-signaling pathways (NKX3.1, PTEN, and p27), and androgens (AR) as critical determinants of the phenotype of prostate-cancer cells. Glutathione S-transferases (GSTP1) are detoxifying enzymes. Cells of prostatic intraepithelial neoplasia, devoid of GSTP1, undergo genomic damage mediated by carcinogens. NKX3.1, PTEN, and p27 regulate the growth and survival of prostate cells in the normal prostate. Inadequate levels of PTEN and NKX3.1 lead to a reduction in p27 levels and to increased proliferation and decreased apoptosis. Androgen receptor (AR) is a transcription factor that is normally activated by its androgen ligand. During androgen withdrawal therapy, the AR signal transduction pathway also could be activated by amplification of the AR gene, by AR gene mutations, or by altered activity of AR coactivators. Through these mechanisms, tumor cells lead to the emergence of androgen-independent prostate cancer.",
BMGC_PW0209,BMG_PW0607,"Bladder cancer groups several types of malignant tumors of the urinary bladder. It is more prevalent in men than in women and combines both risk factors such as tobacco and exposure to certain carcinogens and genetic factors. Mutations in genes involved in a number of signaling pathways have been implicated in the development of these conditions. [KEGG:map05219, PMID:16474624, PMID:17158541]","The urothelium covers the luminal surface of almost the entire urinary tract, extending from the renal pelvis, through the ureter and bladder, to the proximal urethra. The majority of urothelial carcinoma are bladder carcinomas, and urothelial carcinomas of the renal pelvis and ureter account for only approximately 7% of the total. Urothelial tumours arise and evolve through divergent phenotypic pathways. Some tumours progress from urothelial hyperplasia to low-grade non-invasive superficial papillary tumours. More aggressive variants arise either from flat, high-grade carcinoma in situ (CIS) and progress to invasive tumours, or they arise de novo as invasive tumours. Low-grade papillary tumors frequently show a constitutive activation of the receptor tyrosine kinase-Ras pathway, exhibiting activating mutations in the HRAS and fibroblast growth factor receptor 3 (FGFR3) genes. In contrast, CIS and invasive tumors frequently show alterations in the TP53 and RB genes and pathways. Invasion and metastases are promoted by several factors that alter the tumour microenvironment, including the aberrant expression of E-cadherins (E-cad), matrix metalloproteinases (MMPs), angiogenic factors such as vascular endothelial growth factor (VEGF).",
BMGC_PW0210,BMG_PW0608,"Endometrial cancer affects the lining of the uterus, or endometrium. Hormonal and genetic alterations play a role in the development of this carcinoma type. Mutations in genes acting in several pathways have been associated with the condition and its types. [KEGG:map05213, PMID:12583434, PMID:15947972, PMID:16508724]","Endometrial cancer (EC) is the most common gynaecological malignancy and the fourth most common malignancy in women in the developed world after breast, colorectal and lung cancer. Two types of endometrial carcinoma are distinguished with respect to biology and clinical course. Type-I carcinoma is related to hyperestrogenism by association with endometrial hyperplasia, frequent expression of estrogen and progesterone receptors and younger age, whereas type-II carcinoma is unrelated to estrogen, associated with atrophic endometrium, frequent lack of estrogen and progesterone receptors and older age. The morphologic differences in these cancers are mirrored in their molecular genetic profile with type I showing defects in DNA-mismatch repair and mutations in PTEN, K-ras, and beta-catenin, and type II showing aneuploidy, p53 mutations, and her2/neu amplification.",
BMGC_PW0211,BMG_PW0609,"Colorectal cancer are malignant tumors of the colon and rectum. Both risk factors usually relating to life style such as physical exercise or use of tobacco and genetics contribute to the development of the condition. Mutations in the components of canonical Wnt and Smad-dependent TGF-beta signaling and of DNA mismatch repair pathways  have been associated with the pathogenesis of colorectal cancer pathway. [KEGG:map05210, OneLook:www.onelook.com]","Colorectal cancer (CRC) is the second largest cause of cancer-related deaths in Western countries. CRC arises from the colorectal epithelium as a result of the accumulation of genetic alterations in defined oncogenes and tumour suppressor genes (TSG). Two major mechanisms of genomic instability have been identified in sporadic CRC progression. The first, known as chromosomal instability (CIN), results from a series of genetic changes that involve the activation of oncogenes such as K-ras and inactivation of TSG such as p53, DCC/Smad4, and APC. The second, known as microsatellite instability (MSI), results from inactivation of the DNA mismatch repair genes MLH1 and/or MSH2 by hypermethylation of their promoter, and secondary mutation of genes with coding microsatellites, such as transforming growth factor receptor II (TGF-RII) and BAX. Hereditary syndromes have germline mutations in specific genes (mutation in the tumour suppressor gene APC on chromosome 5q in FAP, mutated DNA mismatch repair genes in HNPCC).",
BMGC_PW0212,BMG_PW0623,"Pancreatic cancer, a malignant tumor of the pancreas, has both genetic and predisposing factors. Deregulated pathways, such as TGF-B, PI3K-Akt or RAF/MEK/ERK, have been implicated in the development of pancreatic cancer. [KEGG:map05212, PMID:17898532, PMID:18662538]","Infiltrating ductal adenocarcinoma is the most common malignancy of the pancreas. When most investigators use the term 'pancreatic cancer' they are referring to pancreatic ductal adenocarcinoma (PDA). Normal duct epithelium progresses to infiltrating cancer through a series of histologically defined precursors (PanINs). The overexpression of HER-2/neu and activating point mutations in the K-ras gene occur early, inactivation of the p16 gene at an intermediate stage, and the inactivation of p53, SMAD4, and BRCA2 occur relatively late. Activated K-ras engages multiple effector pathways. Although EGF receptors are conventionally regarded as upstream activators of RAS proteins, they can also act as RAS signal transducers via RAS-induced autocrine activation of the EGFR family ligands. Moreover, PDA shows extensive genomic instability and aneuploidy. Telomere attrition and mutations in p53 and BRCA2 are likely to contribute to these phenotypes. Inactivation of the SMAD4 tumour suppressor gene leads to loss of the inhibitory influence of the transforming growth factor-beta signalling pathway.",
BMGC_PW0213,BMG_PW0635,"In the endoplasmic reticulum, correctly-folded proteins are targeted for further export whereas misfolded proteins are retained and targeted for degradation. [GO:0036503, KEGG:04141, PMID:18075753, PMID:18216874, PMID:22535891]","The endoplasmic reticulum (ER) is a subcellular organelle where proteins are folded with the help of lumenal chaperones. Newly synthesized peptides enter the ER via the sec61 pore and are glycosylated. Correctly folded proteins are packaged into transport vesicles that shuttle them to the Golgi complex. Misfolded proteins are retained within the ER lumen in complex with molecular chaperones. Proteins that are terminally misfolded bind to BiP and are directed toward degradation through the proteasome in a process called ER-associated degradation (ERAD). Accumulation of misfolded proteins in the ER causes ER stress and activates a signaling pathway called the unfolded protein response (UPR). In certain severe situations, however, the protective mechanisms activated by the UPR are not sufficient to restore normal ER function and cells die by apoptosis.",
BMGC_PW0214,BMG_PW0637,"The glycolytic pathway converts the six-carbon glucose to two three-carbon pyruvate molecules. The ten reactions of glycolysis can be subdivided into an energy-consuming 'stage I' and an energy-generating 'stage II'. The net energy yield is two molecules of ATP. Pyruvate can be further oxidized via the citrate cycle, converted to lactose under anaerobic conditions or back to glucose via gluconeogenesis. [GO:0006096, KEGG:00010, PMID:15466941, PMID:3306346, Reactome:R-HSA-70171, SMP:00040]","Glycolysis is the process of converting glucose into pyruvate and generating small amounts of ATP (energy) and NADH (reducing power). It is a central pathway that produces important precursor metabolites: six-carbon compounds of glucose-6P and fructose-6P and three-carbon compounds of glycerone-P, glyceraldehyde-3P, glycerate-3P, phosphoenolpyruvate, and pyruvate [MD:M00001]. Acetyl-CoA, another important precursor metabolite, is produced by oxidative decarboxylation of pyruvate [MD:M00307]. When the enzyme genes of this pathway are examined in completely sequenced genomes, the reaction steps of three-carbon compounds from glycerone-P to pyruvate form a conserved core module [MD:M00002], which is found in almost all organisms and which sometimes contains operon structures in bacterial genomes. Gluconeogenesis is a synthesis pathway of glucose from noncarbohydrate precursors. It is essentially a reversal of glycolysis with minor variations of alternative paths [MD:M00003].","The reactions of glycolysis (e.g., van Wijk and van Solinge 2005) convert glucose 6-phosphate to pyruvate. The entire process is cytosolic. Glucose 6-phosphate is reversibly isomerized to form fructose 6-phosphate. Phosphofructokinase 1 catalyzes the physiologically irreversible phosphorylation of fructose 6-phosphate to form fructose 1,6-bisphosphate. In six reversible reactions, fructose 1,6-bisphosphate is converted to two molecules of phosphoenolpyruvate and two molecules of NAD+ are reduced to NADH + H+. Each molecule of phosphoenolpyruvate reacts with ADP to form ATP and pyruvate in a physiologically irreversible reaction. Under aerobic conditions the NADH +H+ can be reoxidized to NAD+ via electron transport to yield additional ATP, while under anaerobic conditions or in cells lacking mitochondria NAD+ can be regenerated via the reduction of pyruvate to lactate."
BMGC_PW0215,BMG_PW0638,"The gluconeogenic pathway involves the synthesis of glucose from noncarbohydrate precursors. They include the glycolysis products pyruvate and lactate, citric acid cycle intermediates and the carbon skeletons of many amino acids. [GO:0006094, KEGG:00010, PMID:15466941, PMID:6311081, Reactome:R-HSA-70263, SMP:00128]","Glycolysis is the process of converting glucose into pyruvate and generating small amounts of ATP (energy) and NADH (reducing power). It is a central pathway that produces important precursor metabolites: six-carbon compounds of glucose-6P and fructose-6P and three-carbon compounds of glycerone-P, glyceraldehyde-3P, glycerate-3P, phosphoenolpyruvate, and pyruvate [MD:M00001]. Acetyl-CoA, another important precursor metabolite, is produced by oxidative decarboxylation of pyruvate [MD:M00307]. When the enzyme genes of this pathway are examined in completely sequenced genomes, the reaction steps of three-carbon compounds from glycerone-P to pyruvate form a conserved core module [MD:M00002], which is found in almost all organisms and which sometimes contains operon structures in bacterial genomes. Gluconeogenesis is a synthesis pathway of glucose from noncarbohydrate precursors. It is essentially a reversal of glycolysis with minor variations of alternative paths [MD:M00003].","Gluconeogenesis converts mitochondrial pyruvate to cytosolic glucose 6 phosphate which in turn can be hydrolyzed to glucose and exported from the cell. Gluconeogenesis is confined to cells of the liver and kidney and enables glucose synthesis from molecules such as lactate and alanine and other amino acids when exogenous glucose is not available (reviewed, e.g., by Chourpiliadis & Mohiuddin 2022). Gluconeogenesis occurs in two parts: a network of reactions converts mitochondrial pyruvate to cytosolic phosphoenolpyruvate; then phosphoenolpyruvate is converted to glucose 6 phosphate in a single sequence of cytosolic reactions. Three variants of the first part of the process are physiologically important. 1) A series of transport and transamination reactions convert mitochondrial oxaloacetate to cytosolic oxaloacetate which is converted to phosphoenolpyruvate by a hormonally regulated, cytosolic isoform of phosphoenolpyruvate carboxykinase. This variant allows regulated glucose synthesis from lactate. 2) Mitochondrial oxaloacetate is reduced to malate, which is exported to the cytosol and re oxidized to oxaloacetate. This variant provides reducing equivalents to the cytosol, needed for glucose synthesis from amino acids such as alanine and glutamine. 3) Constitutively expressed mitochondrial phosphoenolpyruvate carboxykinase catalyzes the conversion of mitochondrial oxaloacetate to phosphoenolpyruvate which may then be transported to the cytosol. The exact path followed by any one molecule of pyruvate through this reaction network is determined by the tissue in which the reactions are occurring, the source of the pyruvate, and the physiological stress that triggered gluconeogenesis. In the second part of gluconeogenesis, cytosolic phosphoenolpyruvate, however derived, is converted to fructose 1,6 bisphosphate by reactions that are the reverse of steps of glycolysis. Hydrolysis of fructose 1,6 bisphosphate to fructose 6 phosphate is catalyzed by fructose 1,6 bisphosphatase, and fructose 6 phosphate is reversibly isomerized to glucose 6 phosphate. In all cases, the synthesis of glucose from two molecules of pyruvate requires the generation and consumption of two reducing equivalents as cytosolic NADH + H+. For pyruvate derived from lactate (variants 1 and 3), NADH + H+ is generated with the oxidation of lactate to pyruvate in the cytosol (a reaction of pyruvate metabolism not shown in the diagram). For pyruvate derived from amino acids (variant 2), mitochondrial NADH + H+ generated by glutamate dehydrogenase (a reaction of amino acid metabolism, not shown) is used to reduce oxaloacetate to malate, which is transported to the cytosol and re oxidized, generating cytosolic NADH + H+. The synthesis of glucose from pyruvate also requires the consumption of six high energy phosphates, four from ATP and two from GTP."
BMGC_PW0216,BMG_PW0659,"The mismatch repair pathway assures the maintenance of normal Watson-Crick base pairing. Bases incorrectly matched during DNA replication are removed and replaced with the correct ones. [GO:0006298, KEGG:03430, KEGG:map03430, OneLook:www.onelook.com, Reactome:R-HSA-5358508]","DNA mismatch repair (MMR) is a highly conserved biological pathway that plays a key role in maintaining genomic stability. MMR corrects DNA mismatches generated during DNA replication, thereby preventing mutations from becoming permanent in dividing cells. MMR also suppresses homologous recombination and was recently shown to play a role in DNA damage signaling. Defects in MMR are associated with genome-wide instability, predisposition to certain types of cancer including HNPCC, resistance to certain chemotherapeutic agents, and abnormalities in meiosis and sterility in mammalian systems.             The Escherichia coli MMR pathway has been extensively studied and is well characterized. In E. coli, the mismatch-activated MutS-MutL-ATP complex licenses MutH to incise the nearest unmethylated GATC sequence. UvrD and an exonuclease generate a gap. This gap is filled by pol III and DNA ligase. The GATC sites are then methylated by Dam. Several human MMR proteins have been identified based on their homology to E. coli MMR proteins. These include human homologs of MutS and MutL. Although E. coli MutS and MutL proteins are homodimers, human MutS and MutL homologs are heterodimers. The role of hemimethylated dGATC sites as a signal for strand discrimination is not conserved from E. coli to human. Human MMR is presumed to be nick-directed in vivo, and is thought to discriminate daughter and template strands using a strand-specific nick.","The mismatch repair (MMR) system corrects single base mismatches and small insertion and deletion loops (IDLs) of unpaired bases. MMR is primarily associated with DNA replication and is highly conserved across prokaryotes and eukaryotes. MMR consists of the following basic steps: a sensor (MutS homologue) detects a mismatch or IDL, the sensor activates a set of proteins (a MutL homologue and an exonuclease) that select the nascent DNA strand to be repaired, nick the strand, exonucleolytically remove a region of nucleotides containing the mismatch, and finally a DNA polymerase resynthesizes the strand and a ligase seals the remaining nick (reviewed in Kolodner and Marsischkny 1999, Iyer et al. 2006, Li 2008, Fukui 2010, Jiricny 2013). Humans have 2 different MutS complexes. The MSH2:MSH6 heterodimer (MutSalpha) recognizes single base mismatches and small loops of one or two unpaired bases. The MSH2:MSH3 heterodimer (MutSbeta) recognizes loops of two or more unpaired bases. Upon binding a mismatch, the MutS complex becomes activated in an ATP-dependent manner allowing for subsequent downstream interactions and movement on the DNA substrate. (There are two mechanisms proposed: a sliding clamp and a switch diffusion model.) Though the order of steps and structural details are not fully known, the activated MutS complex interacts with MLH1:PMS2 (MutLalpha) and PCNA, the sliding clamp present at replication foci. The role of PCNA is multifaceted as it may act as a processivity factor in recruiting MMR proteins to replicating DNA, interact with MLH1:PMS2 and Exonuclease 1 (EXO1) to initiate excision of the recently replicated strand and direct DNA polymerase delta to initiate replacement of bases. MLH1:PMS2 makes an incision in the strand to be repaired and EXO1 extends the incision to make a single-stranded gap of up to 1 kb that removes the mismatched base(s). (Based on assays of purified human proteins, there is also a variant of the mismatch repair pathway that does not require EXO1, however the mechanism is not clear. EXO1 is almost always required, it is possible that the exonuclease activity of DNA polymerase delta may compensate in some situations and it has been proposed that other endonucleases may perform redundant functions in the absence of EXO1.) RPA binds the single-stranded region and a new strand is synthesized across the gap by DNA polymerase delta. The remaining nick is sealed by DNA ligase I (LIG1). Concentrations of MMR proteins MSH2:MSH6 and MLH1:PMS2 increase in human cells during S phase and are at their highest level and activity during this phase of the cell cycle (Edelbrock et al. 2009). Defects in MSH2, MSH6, MLH1, and PMS2 cause hereditary nonpolyposis colorectal cancer (HNPCC, also known as Lynch syndrome) (reviewed in Martin-Lopez and Fishel 2013)."
BMGC_PW0217,BMG_PW0660,"A pathway dealing with repair of double-strand breaks of the DNA or of strand damage such as interstrand cross-links. [GO:0006302, PMID:23085398, PMID:24326623, Reactome:R-HSA-5693532]",,
BMGC_PW0218,BMG_PW0669,"Insulin secretion by pancreatic beta-cells is an important aspect of glucose homeostasis. A major component of glucose-stimulated insulin secretion is represented by the route dependent on the ATP-sensitive potassium channels. However, other contributions are also likely to promote insulin secretion. [GO:0030073, PMID:18728221, PMID:18774732, Reactome:R-HSA-422356]","Pancreatic beta cells are specialised endocrine cells that continuously sense the levels of blood sugar and other fuels and, in response, secrete insulin to maintain normal fuel homeostasis. Glucose-induced insulin secretion and its potentiation constitute the principal mechanism of insulin release. Glucose is transported by the glucose transporter (GLUT) into the pancreatic beta-cell. Metabolism of glucose generates ATP, which inhibits ATP-sensitive K+ channels and causes voltage-dependent Ca2+ influx. Elevation of [Ca2+]i triggers exocytotic release of insulin granules. Insulin secretion is further regulated by several hormones and neurotransmitters. Peptide hormones, such as glucagon-like peptide 1 (GLP-1), increase cAMP levels and thereby potentiate insulin secretion via the combined action of PKA and Epac2. Achetylcholine (ACh), a major parasympathetic neurotransmitter, binds to Gq-coupled receptors and activates phospholipase C- (PLC-), and the stimulatory effects involve activation of protein kinase C (PKC), which stimulates exocytosis. In addition, ACh mobilizes intracellular Ca2+ by activation of IP3 receptors.","Pancreatic beta cells integrate signals from several metabolites and hormones to control the secretion of insulin. In general, glucose triggers insulin secretion while other factors can amplify or inhibit the amount of insulin secreted in response to glucose. Factors which increase insulin secretion include the incretin hormones Glucose-dependent insulinotropic polypeptide (GIP and glucagon-like peptide-1 (GLP-1), acetylcholine, and fatty acids. Factors which inhibit insulin secretion include adrenaline and noradrenaline. Increased blood glucose levels from dietary carbohydrate play a dominant role in insulin release from the beta cells of the pancreas. Glucose catabolism in the beta cell is the transducer that links increased glucose levels to insulin release. Glucose uptake and glycolysis generate cytosolic pyruvate; pyruvate is transported to mitochondria and converted both to oxaloacetate which increases levels of TCA cycle intermediates, and to acetyl-CoA which is oxidized to CO2 via the TCA cycle. The rates of ATP synthesis and transport to the cytosol increase, plasma membrane ATP-sensitive inward rectifying potassium channels (KATP channels) close, the membrane depolarizes, and voltage-gated calcium channels in the membrane open (Muoio and Newgard 2008; Wiederkehr and Wollheim 2006). Elevated calcium concentrations near the plasma membrane cause insulin secretion in two phases: an initial high rate within minutes of glucose stimulation and a slow, sustained release lasting longer than 30 minutes. In the initial phase, 50-100 insulin granules already docked at the membrane are exocytosed. Exocytosis is rendered calcium-dependent by Synaptotagmin V/IX, a calcium-binding membrane protein located in the membrane of the docked granule, although the exact action of Synapototagmin in response to calcium is unknown. Calcium also causes a translocation of reserve granules within the cell towards the plasma membrane for release in the second, sustained phase of secretion. Human cells contain L-type (continually reopening), P/Q-type (long burst), R-type (long burst), and T-type (short burst) calcium channels and these partly account for differences between the two phases of secretion. Other factors that distinguish the two phases are not yet fully known (Bratanova-Tochkova et al. 2002; Henquin 2000; MacDonald et al. 2005)."
BMGC_PW0219,BMG_PW0676,"Fas ligand binding to its receptor triggers a conformational change that allows the receptor to assemble a signaling complex known as DISC, followed by recruitment of pro-caspase-8 and activation of caspase-3 and -7. It is believed that Fas-mediated signaling to elicit apoptosis follows two routes. [GO:0036337, PID:200080, PMID:14744432, Reactome:R-HSA-75157]",,"The Fas family of cell surface receptors initiate the apototic pathway through interaction with the external ligand, FasL. The cytoplasmic domain of Fas interacts with a number of molecules in the transduction of the external signal to the cytoplasmic side of the cell membrane. The most notable cytoplasmic domain is the Death Domain (DD) that is involved in recruiting the FAS-associating death domain-containing protein (FADD). This interaction drives downstream events."
BMGC_PW0220,BMG_PW0677,"Trail-mediated signaling leads to apoptosis via assembly of the DISC complex (Death-Inducing Signaling Complex) downstream of its receptors. [GO:0036462, PID:200068, PMID:14744432, Reactome:R-HSA-75158]",,"Tumor necrosis factor-related apoptosis-inducing ligand or Apo 2 ligand (TRAIL/Apo2L) is a member of the tumor necrosis factor (TNF) family. This group of apoptosis induction pathways all work through protein interactions mediated by the intracellular death domain (DD), encoded within the cytoplasmic domain of the receptor. TRAIL selectively induces apoptosis through its interaction with the Fas-associated death domain protein (FADD) and caspase-8/10 (Wang S & el-Deiry WS 2003; Sprick MR et al. 2002). TRAIL and its receptors, TRAIL-R1 and TRAIL-R2, were shown to be rapidly endocytosed via clathrin-dependent and -independent manner in human Burkitt's lymphoma B cells (BJAB) (Kohlhaas SL et al. 2007). However, FADD and caspase-8 were able to bind TRAIL-R1/R2 in TRAIL-stimulated BJAB cells at 4oC (at which membrane trafficking is inhibited), suggesting that the endocytosis was not required for an assembly of the functional TRAIL DISC complex. Moreover, blocking of clathrin-dependent endocytosis did not interfere with the capacity of TRAIL to promote apoptosis (Kohlhaas SL et al. 2007)."
BMGC_PW0221,BMG_PW0680,"The metabolic pathways for generating glucose to meet the body's glucose needs. Gluconeogenesis in the liver and to some extent in kidney is the major pathway of glucose production; glycogenolysis is another route for generating glucose in these tissues. [GO:0006094, MCW_Libraries:ISBN-13_978-0470-12930-2, Reactome:R-HSA-70263]",,"Gluconeogenesis converts mitochondrial pyruvate to cytosolic glucose 6 phosphate which in turn can be hydrolyzed to glucose and exported from the cell. Gluconeogenesis is confined to cells of the liver and kidney and enables glucose synthesis from molecules such as lactate and alanine and other amino acids when exogenous glucose is not available (reviewed, e.g., by Chourpiliadis & Mohiuddin 2022). Gluconeogenesis occurs in two parts: a network of reactions converts mitochondrial pyruvate to cytosolic phosphoenolpyruvate; then phosphoenolpyruvate is converted to glucose 6 phosphate in a single sequence of cytosolic reactions. Three variants of the first part of the process are physiologically important. 1) A series of transport and transamination reactions convert mitochondrial oxaloacetate to cytosolic oxaloacetate which is converted to phosphoenolpyruvate by a hormonally regulated, cytosolic isoform of phosphoenolpyruvate carboxykinase. This variant allows regulated glucose synthesis from lactate. 2) Mitochondrial oxaloacetate is reduced to malate, which is exported to the cytosol and re oxidized to oxaloacetate. This variant provides reducing equivalents to the cytosol, needed for glucose synthesis from amino acids such as alanine and glutamine. 3) Constitutively expressed mitochondrial phosphoenolpyruvate carboxykinase catalyzes the conversion of mitochondrial oxaloacetate to phosphoenolpyruvate which may then be transported to the cytosol. The exact path followed by any one molecule of pyruvate through this reaction network is determined by the tissue in which the reactions are occurring, the source of the pyruvate, and the physiological stress that triggered gluconeogenesis. In the second part of gluconeogenesis, cytosolic phosphoenolpyruvate, however derived, is converted to fructose 1,6 bisphosphate by reactions that are the reverse of steps of glycolysis. Hydrolysis of fructose 1,6 bisphosphate to fructose 6 phosphate is catalyzed by fructose 1,6 bisphosphatase, and fructose 6 phosphate is reversibly isomerized to glucose 6 phosphate. In all cases, the synthesis of glucose from two molecules of pyruvate requires the generation and consumption of two reducing equivalents as cytosolic NADH + H+. For pyruvate derived from lactate (variants 1 and 3), NADH + H+ is generated with the oxidation of lactate to pyruvate in the cytosol (a reaction of pyruvate metabolism not shown in the diagram). For pyruvate derived from amino acids (variant 2), mitochondrial NADH + H+ generated by glutamate dehydrogenase (a reaction of amino acid metabolism, not shown) is used to reduce oxaloacetate to malate, which is transported to the cytosol and re oxidized, generating cytosolic NADH + H+. The synthesis of glucose from pyruvate also requires the consumption of six high energy phosphates, four from ATP and two from GTP."
BMGC_PW0222,BMG_PW0688,"Those enzymatic reactions involved in the degradation of biphenyl, an aromatic hydrocarbon used as a starting material for the production of polychlorinated biphenyls or as an intermediate for the production of a variety of organic compounds. [GO:0070980, KEGG:map00621, OneLook:www.onelook.com]",,
BMGC_PW0223,BMG_PW0691,"Those metabolic reactions involved in the synthesis of zeatin - a plant hormone derived from adenine. It induces plant growth and has been reported to have anti-aging effects on human skin fibroblasts. [GO:0033398, KEGG:map00908, OneLook:www.onelook.com]",,
BMGC_PW0224,BMG_PW0692,"Those metabolic reactions involved in the synthesis of carotenoids, organic pigments found in plants and other photosynthetic organisms. Some can act as antioxidants. [GO:0016117, KEGG:map00906, OneLook:www.onelook.com]",,
BMGC_PW0225,BMG_PW0693,"Thyroid cancer refers to one of several types of malignant tumors of the thyroid gland of which papillary thyroid cancer is the most frequent, accounting for almost 80% of all cases. The other types include follicular, medullary and anaplastic. [KEGG:map05216, OneLook:www.onelook.com]","Thyroid cancer is the most common endocrine malignancy and accounts for the majority of endocrine cancer- related deaths each year. More than 95% of thyroid carcinomas are derived from follicular cells. Their behavior varies from the indolent growing, well-differentiated papillary and follicular carcinomas (PTC and FTC, respectively) to the extremely aggressive undifferentiated carcinoma (UC). Somatic rearrangements of RET and TRK are almost exclusively found in PTC and may be found in early stages. The most distinctive molecular features of FTC are the prominence of aneuploidy and the high prevalence of RAS mutations and PAX8-PPAR{gamma} rearrangements. p53 seems to play a crucial role in the dedifferentiation process of thyroid carcinoma.",
BMGC_PW0226,BMG_PW0699,"Small cell lung cancer is an aggressive type of lung cancer. Several pathways appear to be deregulated and they include the intrinsic apoptotic pathway, PI3K-Akt signaling and changes in oncogene transcription factors such as Myc and p53. [KEGG:map05222, OneLook:www.onelook.com]","Lung cancer is a leading cause of cancer death among men and women in industrialized countries. Small cell lung carcinoma (SCLC) is a highly aggressive neoplasm, which accounts for approximately 25% of all lung cancer cases. Molecular mechanisms altered in SCLC include induced expression of oncogene, MYC, and loss of tumorsuppressor genes, such as p53, PTEN, RB, and FHIT. The overexpression of MYC proteins in SCLC is largely a result of gene amplification. Such overexpression leads to more rapid proliferation and loss of terminal differentiation. Mutation or deletion of p53 or PTEN can lead to more rapid proliferation and reduced apoptosis. The retinoblastoma gene RB1 encodes a nuclear phosphoprotein that helps to regulate cell-cycle progression. The fragile histidine triad gene FHIT encodes the enzyme diadenosine triphosphate hydrolase, which is thought to have an indirect role in proapoptosis and cell-cycle control.",
BMGC_PW0227,BMG_PW0700,"Non-small cell lung carcinoma groups together several non-small cell lung carcinomas. The main types are represented by squamous cell, adeno- and large-cell carcinoma. Alterations in Ras and epidermal growth factor signaling, among others, have been implicated in the condition. [KEGG:map05223, OneLook:www.onelook.com]","Lung cancer is a leading cause of cancer death among men and women in industrialized countries. Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer and represents a heterogeneous group of cancers, consisting mainly of squamous cell (SCC), adeno (AC) and large-cell carcinoma. Molecular mechanisms altered in NSCLC include activation of oncogenes, such as K-RAS, EGFR and EML4-ALK, and inactivation of tumorsuppressor genes, such as p53, p16INK4a, RAR-beta, and RASSF1. Point mutations within the K-RAS gene inactivate GTPase activity and the p21-RAS protein continuously transmits growth signals to the nucleus. Mutations or overexpression of EGFR leads to a proliferative advantage. EML4-ALK fusion leads to constitutive ALK activation, which causes cell proliferation, invasion, and inhibition of apoptosis. Inactivating mutation of p53 can lead to more rapid proliferation and reduced apoptosis. The protein encoded by the p16INK4a inhibits formation of CDK-cyclin-D complexes by competitive binding of CDK4 and CDK6. Loss of p16INK4a expression is a common feature of NSCLC. RAR-beta is a nuclear receptor that bears vitamin-A-dependent transcriptional activity. RASSF1A is able to form heterodimers with Nore-1, an RAS effector.Therefore loss of RASSF1A might shift the balance of RAS activity towards a growth-promoting effect.",
BMGC_PW0228,BMG_PW0704,"Acute myeloid leukemia is a common type of leukemia among adults. Abnormal cells are present inside the bone marrow that grow very vast and replace healthy blood cells. Several signaling pathways are disrupted and/or constitutively activated. [KEGG:map05221, OneLook:www.onelook.com]","Acute myeloid leukemia (AML) is a disease that is characterized by uncontrolled proliferation of clonal neoplastic cells and accumulation in the bone marrow of blasts with an impaired differentiation program. AML accounts for approximately 80% of all adult leukemias and remains the most common cause of leukemia death. Two major types of genetic events have been described that are crucial for leukemic transformation. A proposed necessary first event is disordered cell growth and upregulation of cell survival genes. The most common of these activating events were observed in the RTK Flt3, in N-Ras and K-Ras, in Kit, and sporadically in other RTKs. Alterations in myeloid transcription factors governing hematopoietic differentiation provide second necessary event for leukemogenesis. Transcription factor fusion proteins such as AML-ETO, PML-RARalpha or PLZF-RARalpha block myeloid cell differentiation by repressing target genes. In other cases, the transcription factors themselves are mutated.",
BMGC_PW0229,BMG_PW0705,"Chronic myeloid leukemia, a slowly progressing condition, is a type of leukemia where too many white blood cells are made in the bone marrow. [KEGG:map05220, OneLook:www.onelook.com]","Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder of a pluripotent stem cell. The natural history of CML has a triphasic clinical course comprising of an initial chronic phase (CP), which is characterized by expansion of functionally normal myeloid cells, followed by an accelerated phase (AP) and finally a more aggressive blast phase (BP), with loss of terminal differentiation capacity. On the cellular level, CML is associated with a specific chromosome abnormality, the t(9; 22) reciprocal translocation that forms the Philadelphia (Ph) chromosome. The Ph chromosome is the result of a molecular rearrangement between the c-ABL proto-oncogene on chromosome 9 and the BCR (breakpoint cluster region) gene on chromosome 22. The BCR/ABL fusion gene encodes p210 BCR/ABL, an oncoprotein, which, unlike the normal p145 c-Abl, has constitutive tyrosine kinase activity and is predominantly localized in the cytoplasm. While fusion of c-ABL and BCR is believed to be the primary cause of the chronic phase of CML, progression to blast crisis requires other molecular changes. Common secondary abnormalities include mutations in TP53, RB, and p16/INK4A, or overexpression of genes such as EVI1. Additional chromosome translocations are also observed,such as t(3;21)(q26;q22), which generates AML1-EVI1.",
BMGC_PW0230,BMG_PW0728,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glycosphingolipids - glycolipids with sugar(s) attached to the ceramide core. Based on the sequences of the core carbohydrate residues, they are classified into a number of series such as lacto- and neolacto-, globo-, ganglio- or muco-series. [GO:0006687, MCW_library:QU4_M235b_2009, PMID:15207828, PMID:17976918, PMID:18845618, Reactome:R-HSA-1660662]",,"The steps involved in the synthesis and degradation of glycosphingolipids (sphingolipids with one or more sugars attached) are annotated here (the topic is reviewed by Gault et al. 2010; Sandhoff & Sandhoff, 2018; Sandhoff et al, 2018)."
BMGC_PW0231,BMG_PW0731,"The de novo synthesis of triacylglycerol, the common form of fatty acid transport and storage. Most triacylglycerols are synthesized in the liver and stored in the adipose tissue. [GO:0019432, MCW_library:QU4_M235b_2009, Reactome:R-HSA-75109]",,"The overall process of triglyceride (triacylglycerol) biosynthesis consists of four biochemical pathways: fatty acyl-CoA biosynthesis, conversion of fatty acyl-CoA to phosphatidic acid, conversion of phosphatidic acid to diacylglycerol, and conversion of diacylglycerol to triacylglycerol."
BMGC_PW0232,BMG_PW0732,"Those enzymatic reactions involved in the degradation of triacylglycerols when energy reserves are low, such as in the fasting state, during exercise or in response to stress. Triacylglycerols are the common form of fatty acid transport and storage. [GO:0019433, MCW_library:QU4_M235b_2009, Reactome:R-HSA-163560]",,"Triacylglycerol is a major energy store in the body and its hydrolysis to yield fatty acids and glycerol is a tightly regulated part of energy metabolism. A central part in this regulation is played by hormone-sensitive lipase (HSL), a neutral lipase abundant in adipocytes and skeletal and cardiac muscle, but also abundant in ovarian and adrenal tissue, where it mediates cholesterol ester hydrolysis, yielding cholesterol for steroid biosynthesis. The hormones to which it is sensitive include catecholamines (e.g., epinephrine), ACTH, and glucagon, all of which trigger signaling cascades that lead to its phosphorylation and activation, and insulin, which sets off events leading to its dephosphorylation and inactivation (Holm et al. 2000; Kraemer and Shen 2002). The processes of triacylglycerol and cholesterol ester hydrolysis are also regulated by subcellular compartmentalization: these lipids are packaged in cytosolic particles and the enzymes responsible for their hydrolysis, and perhaps for additional steps in their metabolism, are organized at the surfaces of these particles (e.g., Brasaemle et al. 2004). This organization is dynamic: the inactive form of HSL is not associated with the particles, but is translocated there after being phosphorylated. Conversely, perilipin, a major constituent of the particle surface, appears to block access of enzymes to the lipids within the particle; its phosphorylation allows greater access. Here, HSL-mediated triacylglycerol hydrolysis is described as a pathway containing twelve reactions. The first six of these involve activation: phosphorylation of HSL, dimerization of HSL, disruption of CGI-58:perilipin complexes at the surfaces of cytosolic lipid particles, phosphorylation of perilipin, association of phosphorylated HSL with FABP, and translocation of HSL from the cytosol to the surfaces of lipid particles. The next four reactions are the hydrolysis reactions themselves: the hydrolysis of cholesterol esters, and the successive removal of three fatty acids from triacylglycerol. The last two reactions, dephosphorylation of perilipin and HSL, negatively regulate the pathway. These events are outlined in the figure below. Inputs (substrates) and outputs (products) of individual reactions are connected by black arrows; blue lines connect output activated enzymes to the other reactions that they catalyze. Despite the undoubted importance of these reactions in normal human energy metabolism and in the pathology of diseases such as type II diabetes, they have been studied only to a limited extent in human cells and tissues. Most experimental data are derived instead from two rodent model systems: primary adipocytes from rats, and mouse 3T3-L1 cells induced to differentiate into adipocytes."
BMGC_PW0233,BMG_PW0765,"Those metabolic reactions involved in the synthesis of C19-steroid hormones. Pregnenolone, a C21 steroid derived from cholesterol, and progesterone, to which pregnenolone can be converted, provide the starting material for the C21, C19 and C18 steroid hormones. The C19 class is represented by androgens such as testosterone. [GO:0006702, PMID:17926129, PMID:18720009, Reactome:R-HSA-193048]",,Androgens are the determining factors for male development and behaviour in vertebrates (Miller 2002).
BMGC_PW0234,BMG_PW0766,"Mineralocorticoids are a group of C21 steroid hormones synthesized by the adrenal cortex and so named because of their effects on the concentration of sodium as well as potassium and chloride. The group is best exemplified by aldosterone. [GO:0006705, OneLook:www.onelook.com, Reactome:R-HSA-193993]",,"Aldosterone, the major human mineralocorticoid, is synthesized in the zona glomerulosa of the adrenal cortex from pregnenolone. Pregnenolone is converted to progesterone in two reactions, both catalyzed by 3-beta-hydroxysteroid dehydrogenase/isomerase. Progesterone is hydroxylated by CYP21A2 to form deoxycorticosterone, which in turn is converted to aldosterone in a three-reaction sequence catalyzed by CYP11B2 (Payne and Hales 2004)."
BMGC_PW0235,BMG_PW0767,"Those metabolic reactions involved in the synthesis of glucocorticoids, a group of C21 steroid hormones synthesized by the adrenal cortex and so named because of their effects on glucose metabolism. They also play a role in developmental processes and the immune system. The group is best exemplified by cortisol. [GO:0006704, OneLook:www.onelook.com, Reactome:R-HSA-194002]",,"Cortisol, the major human glucocorticoid, is synthesized in the zona fasciculata of the adrenal cortex from pregnenolone. Pregnenolone is converted to 17alpha-hydoxyprogesterone in two reactions, both catalyzed by 3-beta-hydroxysteroid dehydrogenase/isomerase. 17Alpha-hydroxyprogesterone is hydroxylated by CYP21A2 to form 11-deoxycortisol, which in turn is converted to cortisol by CYP11B1. The conversion of the active steroid hormone, cortisol, to inactive cortisone occurs in many tissues, notably the liver (Payne and Hales 2004)."
BMGC_PW0236,BMG_PW0771,"Those metabolic reactions involved in the synthesis of acetoacetate and beta-hydroxybutyrate, also known as ketone bodies, although only acetoacetate is a ketone. Generally, the acetyl-CoA derived from fatty acid oxidation enters the citrate cycle. In the liver, a substantial fraction of acetyl-CoA is converted to ketone bodies which are then released into the bloodstream to supply peripheral tissues. [GO:0042181, KEGG:map00072, MCW_Libraries:QU4_V876f_2008, Reactome:R-HSA-77111]",,"In a healthy, well-nourished individual, the production of ketone bodies occurs at a relatively low rate. During periods of normal physiological responses to carbohydrate shortages, the liver increases the production of ketone bodies from acetyl-CoA generated from fatty acid oxidation. This allows heart and skeletal muscle to use ketone bodies as the primary source of energy, thereby preserving the limited glucose supply for use in brain tissue. In untreated diabetes mellitus, a huge buildup of ketone bodies occurs due to an increase in fatty acid oxidation. The production of ketone bodies exceeds the ability of peripheral tissues to oxidize them, and results in lowering the pH of blood. Blood acidification is dangerous, chiefly as it impairs the ability of hemoglobin to bind oxygen. Ketone body synthesis proceeds via the synthesis of ccetoacetic acid in three steps from acetyl CoA, followed by the reduction of acetoacetic acid to beta-hydroxybutyrate. In the body, these reactions occur in the mitochondria of liver cells (Sass 2011)."
BMGC_PW0237,BMG_PW0772,"Those metabolic reactions that convert acetoacetate and beta-hydroxybutyrate back to acetyl-CoA, which then can enter the citrate cycle for energy production. Ketone bodies are synthesized in the liver and released into the bloodstream to supply fuel to peripheral tissues, heart and skeletal muscle in particular and during starvation, the brain. [GO:0046952, KEGG:map00072, MCW_Libraries:QU4_V876f_2008, Reactome:R-HSA-77108]",,"The levels of acetone in ketone bodies are much lower than those of acetoacetic acid and beta-hydroxybutyric acid. Acetone cannot be converted back to acetyl-CoA, and is excreted in urine, or breathed out through the lungs. Extrahepatic tissues utilize ketone bodies by converting the beta-hydroxybutyrate successively to acetoacetate, acetoacetatyl-CoA, finally to acetyl-CoA (Sass 2011)."
BMGC_PW0238,BMG_PW0775,"Those metabolic reactions involved in the synthesis of C18-steroid hormones. Pregnenolone, a C21 steroid derived from cholesterol, and progesterone, to which pregnenolone can be converted, provide the starting material for the C21, C19 and C18 steroid hormones. The C18 class is represented by estrogens. The major natural estrogens are beta-estradiol - the primary estrogen, the estrone of menopause and the estriol of pregnancy. [GO:0006703, OneLook:www.onelook.com, PMID:17926129, Reactome:R-HSA-193144]",,"In female vertebrates, estrogens control reproductive system development and reproductive functions (Payne AH and Hales DB, 2004)."
BMGC_PW0239,BMG_PW0788,"Epinephrine acts as a hormone and a neurotransmitter. It promotes various actions by signaling via various adrenergic receptors, of the G-protein coupled receptor type. The alpha 2 receptors couple to the Galphai subunit. [OneLook:www.onelook.com, Reactome:R-HSA-392023]",,"Adrenaline (epinephrine) signalling via the alpha-2 adrenergic receptor has many effects including inhibition of insulin release in pancreas, induction of glucagon release from pancreas, contraction of sphincters of the gastrointestinal tract, negative feedback processes in neuronal synapses and stimulation of platelet aggregation. This receptor preferentially couples to members of the Gi class of heterotrimeric G-proteins, leading to inhibition af adenylate cyclase and thereby decreased cAMP levels."
BMGC_PW0240,BMG_PW0803,"MicroRNAs (miRNAs) are a large family of small RNAs involved in the post-transcriptional regulation of gene expression. The biogenesis and function of miRNA is subject to complex control. Deregulation of miRNA expression has been linked to many diseases including cancer. [GO:0035196, PMID:20471939, PMID:20661255, PMID:20885409, Reactome:R-HSA-203927]",,"Biogenesis of microRNAs (miRNAs) can be summarized in five steps (reviewed in Ketting 2011, Nowotny and Yang 2009, Kim et al. 2009, Chua et al. 2009, Hannon and He 2004): 1. Transcription. miRNA transcripts may come from autonomously transcribed genes, they may be contained in cotranscripts with other genes, or they may be located in introns of host genes. Most miRNAs are transcribed by RNA polymerase II, however a few miRNAs originate as RNA polymerase III cotranscripts with neighboring repetitive elements. The initial transcript, termed a primary microRNA (pri-miRNA), contains an imperfectly double-stranded region within a hairpin loop. Longer sequences extend from the 5' and 3' ends of the hairpin and may also contain double-stranded regions. 2. Cleavage by DROSHA. The 5' and 3' ends of the pri-miRNA are removed during endoribonucleolytic cleavage by the DROSHA nuclease in a complex with the RNA-binding protein DGCR8 (the Microprocessor complex). The cleavage product is a short hairpin of about 60 to 70 nt called the pre-microRNA (pre-miRNA). 3. Nuclear export by Exportin-5. The resulting pre-miRNA is bound by Exportin-5 in a complex with Ran and GTP. The complex translocates the pre-miRNA through the nuclear pore into the cytoplasm. 4. Cleavage by DICER1. Once in the cytoplasm the pre-miRNA is bound by the RISC loading complex which contains DICER1, an Argonaute protein and either TARBP2 or PRKRA. DICER1 cleaves the pre-miRNA to yield an imperfectly double-stranded miRNA of about 21 to 23 nucleotides. At this stage the double-stranded miRNA has protruding single-stranded 3' ends of 2-3 nt. 5. Incorporation into RNA-Induced Silencing Complex (RISC) and strand selection. The double-stranded miRNA is passed to a Argonaute protein contained in the RISC loading complex. One strand, the passenger strand, will be removed and degraded; the other strand, the guide strand, will be retained and will guide the Argonaute:miRNA complex (RISC) to target mRNAs. The human genome encodes 4 Argonaute proteins (AGO1 (EIF2C1), AGO2 (EIF2C2), AGO3 (EIF2C3), AGO4 (EIF2C4)), however only AGO2 (EIF2C2) can cleave target mRNAs with perfect or nearly perfect complementarity to the guide miRNA. For complexes that contain AGO2, cleavage of the passenger strand of the double-stranded miRNA accompanies removal of the passenger strand. Complexes containing other Argonautes may use a helicase to remove the passenger strand but this is not fully known. The resulting miRNA-loaded AGO2 is predominantly located in complexes with TARBP2 or PRKRA at the cytosolic face of the rough endoplasmic reticulum. AGO2, TARBP2, and DICER1 are also observed in the nucleus."
BMGC_PW0241,BMG_PW0809,"Toll-like receptors represent a large and the better understood family of pattern recognition receptors that sense an array of exogenous structures, and recent evidence shows they can also recognize defective endogenous molecules. The intracellular signaling cascades they set in motion lead to the expression of inflammatory mediators. [GO:0002224, KEGG:04620, PMID:20303867, PMID:20303872, Reactome:R-HSA-168898]","Specific families of pattern recognition receptors are responsible for detecting microbial pathogens and generating innate immune responses. Toll-like receptors (TLRs) are membrane-bound receptors identified as homologs of Toll in Drosophila. Mammalian TLRs are expressed on innate immune cells, such as macrophages and dendritic cells, and respond to the membrane components of Gram-positive or Gram-negative bacteria. Pathogen recognition by TLRs provokes rapid activation of innate immunity by inducing production of proinflammatory cytokines and upregulation of costimulatory molecules. TLR signaling pathways are separated into two groups: a MyD88-dependent pathway that leads to the production of proinflammatory cytokines with quick activation of NF-{kappa}B and MAPK, and a MyD88-independent pathway associated with the induction of IFN-beta and IFN-inducible genes, and maturation of dendritic cells with slow activation of NF-{kappa}B and MAPK.","In human, ten members of the Toll-like receptor (TLR) family (TLR1-TLR10) have been identified (TLR11 has been found in mouse, but not in human). All TLRs have a similar Toll/IL-1 receptor (TIR) domain in their cytoplasmic region and an Ig-like domain in the extracellular region, where each is enriched with a varying number of leucine-rich repeats (LRRs). Each TLR can recognize specific microbial pathogen components. The binding pathogenic component to TLR initializes signaling pathways that lead to induction of Interferon alpha/beta and inflammatory cytokines. There are two main signaling pathways. The first is a MyD88-dependent pathway that is common to all TLRs, except TLR3; the second is a TRIF(TICAM1)-dependent pathway that is peculiar to TLR3 and TLR4. TLR4-mediated signaling pathway via TRIF requires adapter molecule TRAM (TRIF-related adapter molecule or TICAM2). TRAM is thought to bridge between the activated TLR4 complex and TRIF.(Takeda & Akira 2004; Akira 2003; Takeda & Akira 2005; Kawai 2005; Heine & Ulmer 2005). This pathway is organized as trafficking and processing of TLR, various TLR cascades (TLR10,TLR3,TLR5,TLR7/8,TLR9,TLR4,TLR2) and their regulation."
BMGC_PW0242,BMG_PW0811,"This family of pattern recognition receptors are cytoplasmic proteins that recognize exogenous cytoplasmic DNA. The signaling cascades they set in motion lead to the expression of inflammatory mediators. [GO:0039529, KEGG:04622, PMID:20303867, PMID:20303872]","Specific families of pattern recognition receptors are responsible for detecting viral pathogens and generating innate immune responses. Non-self RNA appearing in a cell as a result of intracellular viral replication is recognized by a family of cytosolic RNA helicases termed RIG-I-like receptors (RLRs). The RLR proteins include RIG-I, MDA5, and LGP2 and are expressed in both immune and nonimmune cells. Upon recognition of viral nucleic acids, RLRs recruit specific intracellular adaptor proteins to initiate signaling pathways that lead to the synthesis of type I interferon and other inflammatory cytokines, which are important for eliminating viruses.",
BMGC_PW0243,BMG_PW0812,"NOD-like receptors are cytosolic proteins that recognize components of bacterial peptidoglycans. The signaling cascades they set in motion lead to the expression of inflammatory mediators. [GO:0035872, KEGG:04621, PMID:20303867, PMID:20303872, Reactome:R-HSA-168643]","Specific families of pattern recognition receptors are responsible for detecting various pathogens and generating innate immune responses. The intracellular NOD-like receptor (NLR) family contains more than 20 members in mammals and plays a pivotal role in the recognition of intracellular ligands. NOD1 and NOD2, two prototypic NLRs, sense the cytosolic presence of the bacterial peptidoglycan fragments that escaped from endosomal compartments, driving the activation of NF-{kappa}B and MAPK, cytokine production and apoptosis. On the other hand, a different set of NLRs induces caspase-1 activation through the assembly of multiprotein complexes called inflammasomes. The activated of caspase-1 regulates maturation of the pro-inflammatory cytokines IL-1B, IL-18 and drives pyroptosis.","The innate immune system is the first line of defense against invading microorganisms, a broad specificity response characterized by the recruitment and activation of phagocytes and the release of anti-bacterial peptides. The receptors involved recognize conserved molecules present in microbes called pathogen-associated molecular patterns (PAMPs), and/or molecules that are produced as a result of tissue injury, the damage associated molecular pattern molecules (DAMPs). PAMPs are essential to the pathogen and therefore unlikely to vary. Examples are lipopolysaccharide (LPS), peptidoglycans (PGNs) and viral RNA. DAMPs include intracellular proteins, such as heat-shock proteins and extracellular matrix proteins released by tissue injury, such as hyaluronan fragments. Non-protein DAMPs include ATP, uric acid, heparin sulfate and dsDNA. The receptors for these factors are referred to collectively as pathogen- or pattern-recognition receptors (PRRs). The best studied of these are the membrane-associated Toll-like receptor family. Less well studied but more numerous are the intracellular nucleotide-binding domain, leucine rich repeat containing receptors (NLRs) also called nucleotide binding oligomerization domain (NOD)-like receptors, a family with over 20 members in humans and over 30 in mice. These recognise PAMPs/DAMPs from phagocytosed microorganisms or from intracellular infections (Kobayashi et al. 2003, Proell et al. 2008, Wilmanski et al. 2008). Some NLRs are involved in process unrelated to pathogen detection such as tissue homeostasis, apoptosis, graft-versus-host disease and early development (Kufer & Sansonetti 2011). Structurally NLRs can be subdivided into the caspase-recruitment domain (CARD)-containing NLRCs (NODs) and the pyrin domain (PYD)-containing NLRPs (NALPs), plus outliers including ice protease (caspase-1) activating factor (IPAF) (Martinon & Tschopp, 2005). In practical terms, NLRs can be divided into the relatively well characterized NOD1/2 which signal via RIP2 primarily to NFkappaB, and the remainder, some of which participate in macromolecular structures called Inflammasomes that activate caspases. Mutations in several members of the NLR protein family have been linked to inflammatory diseases, suggesting these molecules play important roles in maintaining host-pathogen interactions and inflammatory responses. Most NLRs have a tripartite structure consisting of a variable amino-terminal domain, a central nucleotide-binding oligomerization domain (NOD or NACHT) that is believed to mediate the formation of self oligomers, and a carboxy-terminal leucine-rich repeat (LRR) that detects PAMPs/DAMPs. In most cases the amino-terminal domain includes protein-interaction modules, such as CARD or PYD, some harbour baculovirus inhibitor repeat (BIR) or other domains. For most characterised NLRs these domains have been attributed to downstream signaling Under resting conditions, NLRs are thought to be present in an autorepressed form, with the LRR folded back onto the NACHT domain preventing oligomerization. Accessory proteins may help maintain the inactive state. PAMP/DAMP exposure is thought to triggers conformational changes that expose the NACHT domain enabling oligomerization and recruitment of effectors, though it should be noted that due to the lack of availability of structural data, the mechanistic details of NLR activation remain largely elusive. New terminology for NOD-like receptors was adopted by the Human Genome Organization (HUGO) in 2008 to standardize the nomenclature of NLRs. The acronym NLR, once standing for NOD-like receptor, now is an abbreviation of 'nucleotide-binding domain, leucine-rich repeat containing' protein. The term NOD-like receptor is officially outdated and replaced by NLRC where the C refers to the CARD domain. However the official gene symbols for NOD1 and NOD2 still contain NOD and this general term is still widely used."
BMGC_PW0244,BMG_PW0816,"T cell receptor (TCR) signaling in developing thymocytes is important for the establishment of CD4 and CD8 lineages. Mature T cells express either CD4 or CD8 co-receptors which are essential for the interaction with peptide-bound class II or class I MHC complexes to elicit CD4 T helper (Th) or CD8 cytotoxic T lymphocyte responses, respectively. In either case, T cell-initiated signaling activates the expression of genes whose products mediate these responses. [GO:0050852, KEGG:04660, MCW_library:Handbook_of_cellular_and_molecular_immunology, PMID:16448548, PMID:20537906, Reactome:R-HSA-202403]","Activation of T lymphocytes is a key event for an efficient response of the immune system. It requires the involvement of the T-cell receptor (TCR) as well as costimulatory molecules such as CD28. Engagement of these receptors through the interaction with a foreign antigen associated with major histocompatibility complex molecules and CD28 counter-receptors B7.1/B7.2, respectively, results in a series of signaling cascades. These cascades comprise an array of protein-tyrosine kinases, phosphatases, GTP-binding proteins and adaptor proteins that regulate generic and specialised functions, leading to T-cell proliferation, cytokine production and differentiation into effector cells.","The TCR is a multisubunit complex that consists of clonotypic alpha/beta chains noncovalently associated with the invariant CD3 delta/epsilon/gamma and TCR zeta chains. T cell activation by antigen presenting cells (APCs) results in the activation of protein tyrosine kinases (PTKs) that associate with CD3 and TCR zeta subunits and the co-receptor CD4. Members of the Src kinases (Lck), Syk kinases (ZAP-70), Tec (Itk) and Csk families of nonreceptor PTKs play a crucial role in T cell activation. Activation of PTKs following TCR engagement results in the recruitment and tyrosine phosphorylation of enzymes such as phospholipase C gamma1 and Vav as well as critical adaptor proteins such as LAT, SLP-76 and Gads. These proximal activation leads to reorganization of the cytoskeleton as well as transcription activation of multiple genes leading to T lymphocyte proliferation, differentiation and/or effector function."
BMGC_PW0245,BMG_PW0817,"Antigen recognition by B cell receptors initiates signaling cascades that activate the expression of genes whose products are important for B cell functional responses. [GO:0050853, KEGG:04662, MCW_library:Handbook_on_cellular_and_molecular_immunology, PMID:19827951, PMID:20591989, Reactome:R-HSA-983705]","B cells are an important component of adaptive immunity. They produce and secrete millions of different antibody molecules, each of which recognizes a different (foreign) antigen. The B cell receptor (BCR) is an integral membrane protein complex that is composed of two immunoglobulin (Ig) heavy chains, two Ig light chains and two heterodimers of Ig-alpha and Ig-beta. After BCR ligation by antigen, three main protein tyrosine kinases (PTKs) -the SRC-family kinase LYN, SYK and the TEC-family kinase BTK- are activated. Phosphatidylinositol 3-kinase (PI3K) and phospholipase C-gamma 2 (PLC-gamma 2) are important downstream effectors of BCR signalling. This signalling ultimately results in the expression of immediate early genes that further activate the expression of other genes involved in B cell proliferation, differentiation and Ig production as well as other processes.","Mature B cells express IgM and IgD immunoglobulins which are complexed at the plasma membrane with Ig-alpha (CD79A, MB-1) and Ig-beta (CD79B, B29) to form the B cell receptor (BCR) (Fu et al. 1974, Fu et al. 1975, Kunkel et al. 1975, Van Noesel et al. 1992, Sanchez et al. 1993, reviewed in Brezski and Monroe 2008). Binding of antigen to the immunoglobulin activates phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) in the cytoplasmic tails of Ig-alpha and Ig-beta by Src family tyrosine kinases, including LYN, FYN, and BLK (Nel et al. 1984, Yamanashi et al. 1991, Flaswinkel and Reth 1994, Saouaf et al. 1994, Hata et al. 1994, Saouaf et al. 1995, reviewed in Gauld and Cambier 2004, reviewed in Harwood and Batista 2010). The protein kinase SYK binds the phosphorylated immunoreceptor tyrosine-activated motifs (ITAMs) on the cytoplasmic tails of Ig-alpha (CD79A, MB-1) and Ig-beta (CD79B, B29) (Wienands et al. 1995, Rowley et al. 1995, Tsang et al. 2008). The binding causes the activation and autophosphorylation of SYK (Law et al. 1994, Baldock et al. 2000, Irish et al. 2006, Tsang et al. 2008, reviewed in Bradshaw 2010). Activated SYK and other kinases phosphorylate BLNK (SLP-65), BCAP, and CD19 which serve as scaffolds for the assembly of large complexes, the signalosomes, by recruiting phosphoinositol 3-kinase (PI3K), phospholipase C gamma (predominantly PLC-gamma2 in B cells, Coggeshall et al. 1992), NCK, BAM32, BTK, VAV1, and SHC. The effectors are phosphorylated by SYK and other kinases. PLC-gamma associated with BLNK hydrolyzes phosphatidylinositol-4,5-bisphosphate to yield inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (Carter et al. 1991, Kim et al. 2004). IP3 binds receptors on the endoplasmic reticulum and causes release of calcium ions from the ER into the cytosol. The depletion of calcium from the ER in turn activates STIM1 to interact with ORAI and TRPC1 channels in the plasma membrane, resulting in an influx of extracellular calcium ions (Muik et al. 2008, Luik et al. 2008, Park et al. 2009, Mori et al. 2002). PI3K associated with BCAP and CD19 phosphorylates phosphatidylinositol 4,5-bisphosphate to yield phosphatidyinositol 3,4,5-trisphosphate. Second messengers (calcium, diacylglycerol, inositol 1,4,5-trisphosphate, and phosphatidylinositol 3,4,5-trisphosphate) trigger signaling pathways: NF-kappaB is activated via protein kinase C beta, RAS is activated via RasGRP proteins, NF-AT is activated via calcineurin, and AKT (PKB) is activated via PDK1 (reviewed in Shinohara and Kurosaki 2009, Stone 2006)."
BMGC_PW0246,BMG_PW0820,"The pathways of antigen processing and presentation assure the generation of peptides that have the structural attributes necessary for the association with and their placement near major histocompatibility complex (MHC) molecules. Protein antigens present in vesicular compartments generate class II peptides, those in cytosol, class I. [GO:0019882, KEGG:04612, MCW_library:Handbook_on_cellular_and_molecular_immunology]",,"MHC class I molecules generally present peptide antigens derived from proteins synthesized by the cell itself to CD8+ T cells. However, in some circumstances, antigens from extracellular environment can be presented on MHC class I to stimulate CD8+ T cell immunity, a process termed cross-presentation (Rock & Shen. 2005). Cross-presentation/cross-priming is the ability of antigen presenting cells (APCs) to present exogenous antigens on MHC class I molecules to CD8+ T lymphocytes. Among all the APCs, dendritic cells (DC) are the dominant antigen cross presenting cell types in vivo, although macrophages and B cells appear to cross present model antigens in vitro with a low degree of efficiency (Amigorena & Savina. 2010, Ackermann & Peter Cresswell. 2004). Compared to macrophages, DCs have low levels of lysosomal proteases and exhibit limited lysosomal degradation (Delamarre et al. 2005). This limited proteolysis of internalized antigens by DCs might contribute to their high efficiency for cross-presentation (Monua & Trombetta. 2007). APCs acquire the exogenous antigens through endocytic mechanisms, especially phagosomes for particulate/cell-associated antigens and endosomes for soluble protein antigens. There does not seem to be a unique pathway for cross-presentation but rather different potential mechanisms of cross-presentation have been proposed. These proposed pathways can be classified according to the location where two key events occur: 1) processing of the antigenic protein and 2) loading of the processed peptide on to MHC I molecule (Blanchard & Shastri. 2010). Based on the requirement for TAP and cytosolic proteases two mechanisms have been described, a cytosolic pathway (TAP-dependent and proteasome-dependent) or a vacuolar pathway (TAP- and proteasome-independent) (Blanchard & Shastri. 2010, Amigorena & Savina. 2010). Regarding peptide-loading, MHC I could be loaded in the ER or in the phagosome and recycled to cell surface (Blanchard & Shastri. 2010). Exogenous soluble antigens are cross-presented by dendritic cells, albeit with lower efficiency than for particulate substrates. Soluble antigens destined for cross-presentation are taken up by distinct endocytosis mechanisms which route them into stable early endosomes and then to the cytoplasm for proteasomal degradation and peptide loading. The outcome of the cross-presentation can be either tolerance or immunity (Rock & Shen. 2005)."
BMGC_PW0247,BMG_PW0823,"Cytokine-initiated signaling pathways play important roles in innate and adaptive immunity, as well as cell proliferation and apoptosis. [GO:0019221, KEGG:04060, MCW_library:Handbook_on_molecular_and_cellular_immunology, Reactome:R-HSA-1280215]","Cytokines are soluble extracellular proteins or glycoproteins that are crucial intercellular regulators and mobilizers of cells engaged in innate as well as adaptive inflammatory host defenses, cell growth, differentiation, cell death, angiogenesis, and development and repair processes aimed at the restoration of homeostasis. Cytokines are released by various cells in the body, usually in response to an activating stimulus, and they induce responses through binding to specific receptors on the cell surface of target cells. Cytokines can be grouped by structure into different families and their receptors can likewise be grouped.","Cytokines are small proteins that regulate and mediate immunity, inflammation, and hematopoiesis. They are secreted in response to immune stimuli, and usually act briefly, locally, at very low concentrations. Cytokines bind to specific membrane receptors, which then signal the cell via second messengers, to regulate cellular activity."
BMGC_PW0248,BMG_PW0824,"Chemokine-initiated pathways play important roles in innate and adaptive immunity. They are also involved in development and tissue maintenance. The presence and localization of four cysteines is important for structural folding and is also the basis for chemokine classification. The spacing between the first two cysteine residues divides the family members into four groups. Most mammalian chemokines belong to the CC and CXC families. Chemokines signal via G-protein-coupled receptors to engage distinct G-protein signaling and downstream cascades. [GO:0070098, KEGG:04062, MCW_library:Handbook_on_molecular_and_cellular_immunology, PMID:15062643, Reactome:R-HSA-380108]","Inflammatory immune response requires the recruitment of leukocytes to the site of inflammation upon foreign insult. Chemokines are small chemoattractant peptides that provide directional cues for the cell trafficking and thus are vital for protective host response. In addition, chemokines regulate plethora of biological processes of hematopoietic cells to lead cellular activation, differentiation and survival.             The chemokine signal is transduced by chemokine receptors (G-protein coupled receptors) expressed on the immune cells. After receptor activation, the alpha- and beta-gamma-subunits of G protein dissociate to activate diverse downstream pathways resulting in cellular polarization and actin reorganization. Various members of small GTPases are involved in this process. Induction of nitric oxide and production of reactive oxygen species are as well regulated by chemokine signal via calcium mobilization and diacylglycerol production.","Chemokine receptors are cytokine receptors found on the surface of certain cells, which interact with a type of cytokine called a chemokine. Following interaction, these receptors trigger a flux of intracellular calcium which leads to chemotaxis. Chemokine receptors are divided into different families, CXC chemokine receptors, CC chemokine receptors, CX3C chemokine receptors and XC chemokine receptors that correspond to the 4 distinct subfamilies of chemokines they bind."
BMGC_PW0249,BMG_PW0836,"Acetylcholine signaling plays important roles in the central and peripheral nervous systems and exerts both excitatory and inhibitory effects. It is synthesized from acetyl-CoA and choline by choline O-acetyltransferase. [GO:0095500, KEGG:04725, OneLook:www.onelook.com, PMID:17786266, Reactome:R-HSA-181431]","Acetylcholine (ACh) is a neurotransmitter widely distributed in the central (and also peripheral, autonomic and enteric) nervous system (CNS). In the CNS, ACh facilitates many functions, such as learning, memory, attention and motor control. When released in the synaptic cleft, ACh binds to two distinct types of receptors: Ionotropic nicotinic acetylcholine receptors (nAChR) and metabotropic muscarinic acetylcholine receptors (mAChRs). The activation of nAChR by ACh leads to the rapid influx of Na+ and Ca2+ and subsequent cellular depolarization. Activation of mAChRs is relatively slow (milliseconds to seconds) and, depending on the subtypes present (M1-M5), they directly alter cellular homeostasis of phospholipase C, inositol trisphosphate, cAMP, and free calcium. In the cleft, ACh may also be hydrolyzed by acetylcholinesterase (AChE) into choline and acetate. The choline derived from ACh hydrolysis is recovered by a presynaptic high-affinity choline transporter (CHT).","Acetylcholine is the neurotransmitter found at neuromuscular junctions, synapses in the ganglia of the visceral motor system, and at a variety of sites within the central nervous system. A great deal is known about the function of cholinergic transmission at the neuromuscular junction and at ganglionic synapses, the actions of ACh in the central nervous system are not as well understood. Acetylcholine is synthesized in nerve terminals from acetyl coenzyme A (acetyl CoA) synthesized from glucose) and choline. This reaction is catalyzed by choline acetyltransferase (ChAT). The presence of acetyltransferase in a neuron is thus a strong indication that ACh is used as one of its transmitters. Choline is present in plasma at a concentration of about 10 mM, and is taken up into cholinergic neurons by a high affinity Na+/choline transporter. About 10,000 molecules of ACh are packaged into each neurotransmitter containing vesicle by a vesicular ACh transporter. Nicotinic acetylcholine receptors (nAchR) are ionotropic receptors that can be activated by nicotine and permeable to of monovalent (sodium, potassium) and divalent cations(calcium), however, the permeability of sodium and/or calcium maybe high or low depending on the subunit composition of the receptor. Nicotinic acetylcholine receptors are expressed widely in the central and peripheral nervous system in the presynaptic terminal, terminal bouton and post synaptic neuron. Functionally nicotinic acetylcholine receptors in the pre synaptic and postsynaptic terminals behave similarly. Nicotinic AChR are a family of acetylcholine gated pentameric receptors that are formed by the association of various combinations of mostly alpha, beta subunits (for the neuronal type) and together with gamma, delta and epsilon subunits (for the muscle type). In addition, receptors may be more diverse due the fact that some receptors have same subunits but the stoichiometry of the subunits is different."
BMGC_PW0250,BMG_PW0839,"Glutamate signaling via the ionotropic AMPA or NMDA and several metabotropic receptors plays important roles in the modulation of synaptic plasticity, long term depression or potentiation, and in learning and memory. [GO:0007215, KEGG:04724, OneLook:www.onelook.com]","Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system(CNS). Glutamate is packaged into synaptic vesicles in the presynaptic terminal. Once released into the synaptic cleft, glutamate acts on postsynaptic ionotropic glutamate receptors (iGluRs) to mediate fast excitatory synaptic transmission. Glutamate can also act on metabotropic glutamate receptors (mGluRs) and exert a variety of modulatory effects through their coupling to G proteins and the subsequent recruitment of second messenger systems. Presynaptically localized Group II and Group III mGluRs are thought to represent the classical inhibitory autoreceptor mechanism that suppresses excess glutamate release. After its action on these receptors, glutamate can be removed from the synaptic cleft by EAATs located either on the presynaptic terminal, neighboring glial cells, or the postsynaptic neuron. In glia, glutamate is converted to glutamine, which is then transported back to the presynaptic terminal and converted back to glutamate.",
BMGC_PW0251,BMG_PW0840,"Glutamate signaling via the ionotropic NMDA glutamate receptor plays important roles in synaptic plasticity and in learning and memory. The receptor is ligand-gated and voltage-dependent and requires glycine as a co-agonist. [GO:0035235, OneLook:www.onelook.com, Reactome:R-HSA-442755]",,"NMDA receptors are a subtype of ionotropic glutamate receptors that are specifically activated by a glutamate agonist N-methyl-D-aspartate (NMDA). Activation of NMDA receptors involves opening of the ion channel that allows the influx of Ca2+. NMDA receptors are central to activity dependent changes in synaptic strength and are predominantly involved in the synaptic plasticity that pertains to learning and memory. A unique feature of NMDA receptors, unlike other glutamate receptors, is the requirement for dual activation, both voltage-dependent and ligand-dependent activation. The ligand-dependent activation of NMDA receptors requires co-activation by two ligands, glutamate and glycine. However, at resting membrane potential, the pore of ligand-bound NMDA receptors is blocked by Mg2+. The voltage dependent Mg2+ block is relieved upon depolarization of the post-synaptic membrane. NMDA receptors are coincidence detectors, and are activated only if there is a simultaneous activation of both pre- and post-synaptic cell. Upon activation, NMDA receptors allow the influx of Ca2+ that initiates various molecular signaling cascades involved in the processes of learning and memory. For review, please refer to Cohen and Greenberg 2008, Hardingham and Bading 2010, Traynelis et al. 2010, and Paoletti et al. 2013."
BMGC_PW0252,BMG_PW0841,"Glutamate signaling via the ionotropic AMPA receptor plays important roles in long-term potentiation (LTP). The AMPA receptors are both receptors and cation channels. [GO:0035235, OneLook:www.onelook.com, Reactome:R-HSA-399721]",,"Excitatory synaptic transmission in the brain is carried out by glutamate receptors through the activation of both ionotropic and metabotropic receptors. Ionotropic glutamate receptors are of three subtypes based on distinct physiologic properties and their differential binding of exogenous ligands namely NMDA (N-methyl D-aspartate), AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and Kainate . The ionotropic receptors are glutamate gated ion channels that initiate signaling by influx of ions, and are comprised of subunits with distinct structures and distinguished based on their agonist binding. Even though all three types of receptors are found at the glutamatergic synapses yet they exhibit great diversity in the synaptic distribution. The metabotropic glutamate receptors are a family of G-protein coupled receptors that are slow acting. Fast excitatory synaptic transmission is carried out through AMPA receptors. Post-synaptic transmission involves binding of the ligand such as glutamate/AMPA to the AMPA receptor resulting in the Na influx which causes depolarization of the membrane. NMDA receptors are blocked by Mg at resting membrane potential. NMDA receptors are activated upon coincident depolarization and glutamate binding are activated following AMPA receptor activation.NMDA receptors are blocked by Mg at resting membrane potential. NMDA receptors are Ca permeable and their activity leads to increase in Ca which, leads to upregulation of AMPA receptors at the synapse which causes the long lasting excitatory post-synaptic potential (EPSP) which forms the basis of long term potentiation (LTP). LTP is one form of synaptic plasticity wherein the strength of the synapses is enhanced by either change in the number, increase in the efficacy by phosphorylation or change in the type of receptors. Phosphorylation of AMPA receptors changes the localization of the receptors, increases the single channel conductance, and increases the probability of open channel. GluR1 has four phosphorylation sites; serine 818 (S818) is phosphorylated by PKC and is necessary for LTP, serine 831 (S831) is phosphorylated by CaMKII that increases the delivery of receptors to the synapse and also increased their single channel conductance, threonine (T840) is implicated in LTP. Serine 845 (S845) is phosphorylated by PKA which regulates open channel probability. Long term depression is another form of plasticity wherein the number of AMPA receptors is diminished by either phosphorylation of GluR2 at Ser880 or dephosphorylation of GluR1 by protein phosphatase1, protein phosphatase 2A and protein phosphatase 2B (calcineurin)."
BMGC_PW0253,BMG_PW0842,"Glutamate signaling via the various metabotropic, G protein-coupled receptors plays important roles in both the central and peripheral nervous systems. Based on their structure and physiological function, the receptors have been classified into three groups. Group I receptors couple to Galphaq, group II and III couple to Galphai [GO:0007216, OneLook:www.onelook.com, Reactome:R-HSA-420499]",,"The class C G-protein-coupled receptors are a class of G-protein coupled receptors that include the metabotropic glutamate receptors and several additional receptors (Brauner-Osborne H et al, 2007). Family C GPCRs have a large extracellular N-terminus which binds the orthosteric (endogenous) ligand. The shape of this domain is often likened to a clam. Several allosteric ligands to these receptors have been identified and these bind within the seven transmembrane region."
BMGC_PW0254,BMG_PW0843,"Gamma-aminobutyric acid signals at inhibitory synapses via the type A receptor, which is part of a ligand-gated ion channel, and the type B receptors, which are metabotropic G protein-coupled receptors. [GO:0007214, KEGG:04727, OneLook:www.onelook.com, Reactome:R-HSA-977443]","Gamma aminobutyric acid (GABA) is the most abundant inhibitory neurotransmitter in the mammalian central nervous system (CNS). When released in the synaptic cleft, GABA binds to three major classes of receptors: GABAA, GABAB, and GABAC receptors. GABAA and GABAC receptors are ionotropic and mediate fast GABA responses by triggering chloride channel openings, while GABAB receptors are metabotropic and mediate slower GABA responses by activating G-proteins and influencing second messenger systems. GABAA receptors, the major sites for fast inhibitory neurotransmission in the CNS, are regulated by phosphorylation mechanisms, affecting both their functional properties and their cell surface mobility and trafficking. GABA release by the presynaptic terminal is negatively regulated by GABAB autoreceptors, and is cleared from the extracellular space by GABA transporters (GATs) located either on the presynaptic terminal or neighboring glial cells.","Gamma aminobutyric acid (GABA) receptors are the major inhibitory receptors in human synapses. They are of two types. GABA A receptors are fast-acting ligand gated chloride ion channels that mediate membrane depolarization and thus inhibit neurotransmitter release (G Michels et al Crit Rev Biochem Mol Biol 42, 2007, 3-14). GABA B receptors are slow acting metabotropic Gprotein coupled receptors that act via the inhibitory action of their Galpha/Go subunits on adenylate cyclase to attenuate the actions of PKA. In addition, their Gbeta/gamma subunits interact directly with N and P/Q Ca2+ channels to decrease the release of Ca2+. GABA B receptors also interact with Kir3 K+ channels and increase the influx of K+, leading to cell membrane hyperpolarization and inhibition of channels such as NMDA receptors (A Pinard et al Adv Pharmacol, 58, 2010, 231-55)."
BMGC_PW0255,BMG_PW0852,"The phase I biotransformation pathway involves the conversion of exogenous substances to more polar metabolites. Members of the cytochrome P450 superfamily and to a lesser extent, flavin-containing monooxygenases mediate the reactions. [PMID:19835560, Reactome:R-HSA-211945]",,"Phase 1 of metabolism is concerned with functionalization, that is the introduction or exposure of functional groups on the chemical structure of a compound. This provides a 'handle' for phase 2 conjugating species with which to react with. Many xenobiotics are lipophilic and almost chemically inert (e.g. PAHs) so would not necessarily undergo a phase 2 reaction. Making them more chemically reactive would facilitate their excretion but also increases their chance of reacting with cellular macromolecules (e.g. proteins, DNA). There is a fine balance between producing a more reactive metabolite and conjugation reactions. There are two groups of enzymes in phase 1 - oxidoreductases and hydrolases. Oxidoreductases introduce an oxygen atom into or remove electrons from their substrates. The major oxidoreductase enzyme system is called the P450 monooxygenases. Other systems include flavin-containing monooxygenases (FMO), cyclooxygenases (COX) and monoamine oxidases (MAO). Hydrolases hydrolyse esters, amides, epoxides and glucuronides."
BMGC_PW0256,BMG_PW0853,"The phase II biotransformation pathway involves the conjugation of phase I products to various hydrophilic moieties that renders them more suitable for excretion. Various enzyme superfamilies are involved in carrying out the specific conjugation of metabolites. [PMID:19835560, PMID:20668491, Reactome:R-HSA-156580]",,"Phase II of biotransformation is concerned with conjugation, that is using groups from cofactors to react with functional groups present or introduced from phase I on the compound. The enzymes involved are a set of transferases which perform the transfer of the cofactor group to the substrate. The resultant conjugation results in greatly increasing the excretory potential of compounds. Although most conjugations result in pharmacological inactivation or detoxification, some can result in bioactivation. Most of the phase II enzymes are located in the cytosol except UDP-glucuronosyltransferases (UGT), which are microsomal. Phase II reactions are typically much faster than phase I reactions therefore the rate-limiting step for biotransformation of a compound is usually the phase I reaction. Phase II metabolism can deal with all the products of phase I metabolism, be they reactive (Type I substrate) or unreactive/poorly active (Type II substrate) compounds. With the exception of glutathione, the conjugating species needs to be made chemically reactive after synthesis. The availability of the cofactor in the synthesis may be a rate-limiting factor in some phase II pathways as it may prevent the formation of enough conjugating species to deal with the substrate or it's metabolite. As many substrates and/or their metabolites are chemically reactive, their continued presence may lead to toxicity."
BMGC_PW0257,BMG_PW0854,"Glucuronidation of phase I products by members of the UDP-glucuronosyltranferase superfamily represents the major phase II conjugation pathway. [GO:0052695, PMID:20668491, Reactome:R-HSA-156588]",,"Glucuronidation conjugation utilizes UDP-glucuronosyltransferases (UGTs; EC 2.4.1.17) to catalyze a wide range of diverse endogenous and xenobiotic compounds. Glucuronidation is the major pathway in phase II metabolism and accounts for approximately 35% of drug conjugation. UGTs are microsomal membrane-bound and catalyze the transfer of a glucuronate group of uridine diphosphoglucuronate (UDPGA, a co-substrate) to the functional group of specific substrates. UDPGA is synthesized from glucose-1-phosphate (G1P). G1P is required for glycolysis and is present in high concentrations in the cell, making it is unlikely to be a limiting factor in UDPGA synthesis. UDP is added to G1P to form UDP-glucose which is then dehydrogenated to form UDPGA. The basic reaction is UDP-Glucuronate + acceptor -> UDP + acceptor-beta-D-glucuronide The effect of this conjugation is to confer polarity to the substrate which can then be easily excreted in urine or bile. Functional groups acted on include hydroxyl, carboxylate, amino and sulfate groups. There are 2 families of UGTs, UGT1 and UGT2 which are further sub-divided into 3 subfamilies, UGT1A, UGT2A and UGT2B. There are more than 26 different isozymes in humans, of which 18 are functional proteins. They are composed of 527-530 residues and have a molecular weight of 50-57KDa. The UGT1 family comprises of 9 proteins (UGT1A1, 1A3-1A10) but only 5 have been isolated in humans. Example substrates which are glucuronidated are acetaminophen by UGT1A6 and bilirubin by UGT1A1. Members of the UGT2 subfamily are each encoded by their own genes, in contrast to UGT1As which are encoded at the UGT1 locus. Example substrates are morphine conjugation by UGT2B7 and androgenic steroid conjugation by UGT2B17. Xenobiotics conjugated with glucuronic acid can be substrates for beta-glucuronidase, an enzyme common in gut microflora. This enzyme can release the parent or phase I metabolite which can be reabsorbed. It can then either re-exert it's original effects or be conjugated by glucuronic acid again. This cycle is called enterohepatic circulation and can delay the elimination of the xenobiotic."
BMGC_PW0258,BMG_PW0856,"Those enzymatic reactions involved in the synthesis of pyrimidine nucleotides. A major route for pyrimidine synthesis is the de novo pathway. However, an alternate pathway, the salvage pathway, converts nucleosides generated by DNA or RNA breakdown back to nucleotide monophosphates which can then re-enter the biosynthetic pathway. [GO:0019856, PMID:15096496, PMID:16098809, Reactome:R-HSA-500753]",,"The pyrimidine orotate (orotic acid) is synthesized in a sequence of four reactions, deriving its atoms from glutamine, bicarbonate, and aspartate. A single multifunctional cytosolic enzyme catalyzes the first three of these reactions, while the last one is catalyzed by an enzyme associated with the inner mitochondrial membrane. In two further reactions, catalyzed by a bifunctional cytosolic enzyme, orotate reacts with 1-phosphoribosyl 5-pyrophosphate (PRPP) to yield orotidine 5'-monophosphate, which is decarboxylated to yield uridine 5'-monophosphate (UMP). While several individual reactions in this pathway are reversible, other irreversible reactions drive the pathway in the direction of UMP biosynthesis in the normal cell. All reactions are thus annotated here only in the forward direction. This pathway has been most extensively analyzed at the genetic and biochemical level in hamster cell lines. All three enzymes have also been purified from human sources, however, and the key features of these reactions have been confirmed from studies of this human material (Jones 1980; Webster et al. 2001). All other pyrimidines are synthesized from UMP. The reactions annotaed here, catalyzed by dCMP deaminase and dUTP diphosphatase yield dUMP, which in turn is converted to TMP by thymidylate synthase."
BMGC_PW0259,BMG_PW0858,"The salvage pathway of pyrimidine biosynthesis, mostly used in resting and differentiated cells, allows for the synthesis of pyrimidines from intermediates derived from DNA and RNA degradation pathways. [GO:0008655, PMID:15096496, PMID:16098809, Reactome:R-HSA-73614]",,"In pyrimidine salvage reactions, nucleosides and free bases generated by DNA and RNA breakdown are converted back to nucleotide monophosphates, allowing them to re-enter the pathways of pyrimidine biosynthesis and interconversion."
BMGC_PW0260,BMG_PW0859,"Those enzymatic reactions involved in the degradation of pyrimidines. [GO:0006208, PMID:16098809, Reactome:R-HSA-73621]",,"In parallel sequences of three reactions each, thymine is converted to beta-aminoisobutyrate and uracil is converted to beta-alanine. Both of these molecules are excreted in human urine and appear to be normal end products of pyrimidine catabolism (Griffith 1986; Webster et al. 2001). Mitochondrial AGXT2, however, can also catalyze the transamination of both molecules with pyruvate, yielding 2-oxoacids that can be metabolized further by reactions of branched-chain amino acid and short-chain fatty acid catabolism (Tamaki et al. 2000). The importance of these reactions in normal human pyrimidine catabolism has not been well worked out."
BMGC_PW0261,BMG_PW0861,"Those enzymatic reactions involved in the degradation pathway of purines. Several enzymes are involved in the breakdown of adenine and guanine to uric acid. Primates, birds and other animal excrete uric acid. In other species uric acid is further metabolized to allantoin. [GO:0006145, OneLook:www.onelook.com, Reactome:R-HSA-74259, RGD_library:Lehringer_Principles_of_Biochemistry]",,"The purine bases guanine and hypoxanthine (derived from adenine by events in the purine salvage pathways) are converted to xanthine and then to urate uric acid, which is excreted from the body (Watts 1974). The end-point of this pathway in humans and hominoid primates is unusual. Most other mammals metabolize uric acid further to yield more soluble end products, and much speculation has centered on possible roles for high uric acid levels in normal human physiology."
BMGC_PW0262,BMG_PW0863,"The salvage pathway of purine biosynthesis allows for the synthesis of purines from intermediates derived from DNA and RNA degradation pathways. This is important because some tissues are unable to synthesize purines de novo. [GO:0043101, Reactome:R-HSA-74217]",,"Nucleosides and free bases generated by DNA and RNA breakdown are converted back to nucleotide monophosphates, allowing them to re-enter the pathway of purine biosynthesis and interconversion. Under normal conditions, DNA turnover is limited and deoxyribonucleotide salvage operates at a correspondingly low level (Watts 1974)."
BMGC_PW0263,BMG_PW0873,"Phosphatidylcholine is the predominant phospholipid of eukaryotic membranes. Of the three known biosynthetic pathways, two are found in eukaryotes and one, the CDP-choline pathway, is the best characterized. [GO:0006656, PMID:15749057, Reactome:R-HSA-1483191]",,"De novo (Kennedy pathway) synthesis of phosphatidylcholine (PC) involves phosphorylation of choline (Cho) to phosphocholine (PCho) followed by condensing with cytidine triphosphate (CTP) to form CDP-choline (CDP-Cho). Diacylglycerol (DAG) and CDP-ETA together then form PC. Alternatively, PC is formed when phosphatidylethanolamine (PE) is methylated by phosphatidylethanolamine N-methyltransferase (PEMT) (Henneberry et al. 2002; Wright & McMaster 2002)."
BMGC_PW0264,BMG_PW0877,"Interleukin-1 family mediated signaling plays important roles in innate and adaptive immune responses. The best characterized member of the family is interleukin-1, followed by interleukin-18 and the more recently identified interleukin-33. Other family members are less well characterized. [PMID:20081871, Reactome:R-HSA-446652]",,"The Interleukin-1 (IL1) family of cytokines comprises 11 members, namely Interleukin-1 alpha (IL1A), Interleukin-1 beta (IL1B), Interleukin-1 receptor antagonist protein (IL1RN, IL1RA), Interleukin-18 (IL18), Interleukin-33 (IL33), Interleukin-36 receptor antagonist protein (IL36RN, IL36RA), Interleukin-36 alpha (IL36A), Interleukin-36 beta (IL36B), Interleukin-36 gamma (IL36G), Interleukin-37 (IL37) and Interleukin-38 (IL38). The genes encoding all except IL18 and IL33 are on chromosome 2. They share a common C-terminal three-dimensional structure and with apart from IL1RN they are synthesized without a hydrophobic leader sequence and are not secreted via the classical reticulum endoplasmic-Golgi pathway. IL1B and IL18, are produced as biologically inactive propeptides that are cleaved to produce the mature, active interleukin peptide. The IL1 receptor (IL1R) family comprises 10 members: Interleukin-1 receptor type 1 (IL1R1, IL1RA), Interleukin-1 receptor type 2 (IL1R2, IL1RB), Interleukin-1 receptor accessory protein (IL1RAP, IL1RAcP, IL1R3), Interleukin-18 receptor 1 (IL18R1, IL18RA) , Interleukin-18 receptor accessory protein (IL18RAP, IL18RB), Interleukin-1 receptor-like 1 (IL1RL1, ST2, IL33R), Interleukin-1 receptor-like 2 (IL1RL2, IL36R), Single Ig IL-1-related receptor (SIGIRR, TIR8), Interleukin-1 receptor accessory protein-like 1 (IL1RAPL1, TIGGIR2) and X-linked interleukin-1 receptor accessory protein-like 2 (IL1RAPL2, TIGGIR1). Most of the genes encoding these receptors are on chromosome 2. IL1 family receptors heterodimerize upon cytokine binding. IL1, IL33 and IL36 bind specific receptors, IL1R1, IL1RL1, and IL1RL2 respectively. All use IL1RAP as a co-receptor. IL18 binds IL18R1 and uses IL18RAP as co-receptor. The complexes formed by IL1 family cytokines and their heterodimeric receptors recruit intracellular signaling molecules, including Myeloid differentiation primary response protein MyD88 (MYD88), members of he IL1R-associated kinase (IRAK) family, and TNF receptor-associated factor 6 (TRAF6), activating Nuclear factor NF-kappa-B (NFκB), as well as Mitogen-activated protein kinase 14 (MAPK14, p38), c-Jun N-terminal kinases (JNKs), extracellular signal-regulated kinases (ERKs) and other Mitogen-activated protein kinases (MAPKs)."
BMGC_PW0265,BMG_PW0889,"The interferons represent a subset of cytokines whose signaling is involved in various aspects of innate and adaptive immunity. Based on the type of receptors they employ, interferons have been classified into type I and II. A third type, the lambda interferons, are members of the interleukin 10 family. [GO:0140888, PMID:17502369, PMID:20712454, Reactome:R-HSA-913531]",,"Interferons (IFNs) are cytokines that play a central role in initiating immune responses, especially antiviral and antitumor effects. There are three types of IFNs:Type I (IFN-alpha, -beta and others, such as omega, epsilon, and kappa), Type II (IFN-gamma) and Type III (IFN-lamda). In this module we are mainly focusing on type I IFNs alpha and beta and type II IFN-gamma. Both type I and type II IFNs exert their actions through cognate receptor complexes, IFNAR and IFNGR respectively, present on cell surface membranes. Type I IFNs are broadly expressed heterodimeric receptors composed of the IFNAR1 and IFNAR2 subunits, while the type II IFN receptor consists of IFNGR1 and IFNGR2. Type III interferon lambda has three members: lamda1 (IL-29), lambda2 (IL-28A), and lambda3 (IL-28B) respectively. IFN-lambda signaling is initiated through unique heterodimeric receptor composed of IFN-LR1/IF-28Ralpha and IL10R2 chains. Type I IFNs typically recruit JAK1 and TYK2 proteins to transduce their signals to STAT1 and 2; in combination with IRF9 (IFN-regulatory factor 9), these proteins form the heterotrimeric complex ISGF3. In nucleus ISGF3 binds to IFN-stimulated response elements (ISRE) to promote gene induction. Type II IFNs in turn rely upon the activation of JAKs 1 and 2 and STAT1. Once activated, STAT1 dimerizes to form the transcriptional regulator GAF (IFNG activated factor) and this binds to the IFNG activated sequence (GAS) elements and initiate the transcription of IFNG-responsive genes. Like type I IFNs, IFN-lambda recruits TYK2 and JAK1 kinases and then promote the phosphorylation of STAT1/2, and induce the ISRE3 complex formation."
BMGC_PW0266,BMG_PW0892,"The interleukin-17 family-mediated signaling plays important roles in inflammation and in the development of autoimmunity as well as in the host defense against fungal and bacterial infections. [GO:0097400, PMID:21349428, Reactome:R-HSA-448424]","The interleukin 17 (IL-17) family, a subset of cytokines consisting of IL-17A-F, plays crucial roles in both acute and chronic inflammatory responses. IL-17A, the hallmark cytokine of the newly defined T helper 17 (TH17) cell subset, has important roles in protecting the host against extracellular pathogens, but also promotes inflammatory pathology in autoimmune disease, whereas IL-17F is mainly involved in mucosal host defense mechanisms. IL-17E (IL-25) is an amplifier of Th2 immune responses. IL-17C has biological functions similar to those of IL-17A. The functions of IL-17B and IL-17D remain largely elusive. The IL-17 family signals via their correspondent receptors and activates downstream pathways that include NF-kappaB, MAPKs and C/EBPs to induce the expression of antimicrobial peptides, cytokines and chemokines. The receptor proximal adaptor Act1 (an NF-kappaB activator 1) is considered as the master mediator in IL-17A signaling. It is likely that Act1 is a common signal adaptor also shared by other members mediated signalings in this family.","Interleukin-17 (IL17) is a family of cytokines (Kawaguchi et al. 2004, Gu et al. 2013). IL17A, the founding member of the family is able to induce the production of other cytokines and chemokines, such as IL6, IL8, and granulocyte colony-stimulating factor (G-CSF) in a variety of cell types, including activated T-cells. It plays a pivotal role in host defenses in response to microbial infection and is involved in the pathogenesis of autoimmune diseases and allergic syndromes. IL17 activates several downstream signaling pathways including NFkB, MAPKs and C/EBPs, inducing the expression of antibacterial peptides, proinflammatory chemokines and cytokines and matrix metalloproteases (MMPs). IL17 can stabilize the mRNA of genes induced by TNF-alpha. IL17 signal transduction is mediated by the cytosolic adaptor molecule ACT1 (also known as CIKS). The receptor for IL17D is unknown (Gu et al. 2013)."
BMGC_PW0267,BMG_PW0901,"The interleukin-2 family of cytokines, also known as the gamma(c) family because of the shared gamma(c) receptor, play crucial roles in the regulation of T cells. [PMID:19543225, PMID:21889323, Reactome:R-HSA-451927]",,"The interleukin-2 family (also called the common gamma chain cytokine family) consists of interleukin (IL)2, IL9, IL15 and IL21. Although sometimes considered to be within this family, the IL4 and IL7 receptors can form complexes with other receptor chains and are represented separately in Reactome. Receptors of this family associate with JAK1 and JAK3, primarily activating STAT5, although certain family members can also activate STAT1, STAT3 or STAT6."
BMGC_PW0268,BMG_PW0903,"Interleukin-7, an interleukin-2 family member, is secreted by several cell types and is involved in leukemia progression. [GO:0038111, Reactome:R-HSA-1266695]",,"Interleukin-7 (IL7) is produced primarily by T zone fibroblastic reticular cells found in lymphoid organs, and also expressed by non-hematopoietic stromal cells present in other tissues including the skin, intestine and liver. It is an essential survival factor for lymphocytes, playing a key anti-apoptotic role in T-cell development, as well as mediating peripheral T-cell maintenance and proliferation. This dual function is reflected in a dose-response relationship that distinguishes the survival function from the proliferative activity; low doses of IL7 (<1 ng/ml) sustain only survival, higher doses (>1 ng/ml) promote survival and cell cycling (Kittipatarin et al. 2006, Swainson et al. 2007). The IL7 receptor is a heterodimeric complex of the the common cytokine-receptor gamma chain (IL2RG, CD132, or Gc) and the IL7-receptor alpha chain (IL7R, IL7RA, CD127). Both chains are members of the type 1 cytokine family. Neither chain is unique to the IL7 receptor as IL7R is utilized by the receptor for thymic stromal lymphopoietin (TSLP) while IL2RG is shared with the receptors for IL2, IL4, IL9, IL15 and IL21. IL2RG consists of a single transmembrane region and a 240aa extracellular region that includes a fibronectin type III (FNIII) domain thought to be involved in receptor complex formation. It is expressed on most lymphocyte populations. Null mutations of IL2RG in humans cause X-linked severe combined immunodeficiency (X-SCID), which has a phenotype of severely reduced T-cell and natural killer (NK) cell populations, but normal numbers of B cells. In addition to reduced T- and NK-cell numbers, Il2rg knockout mice also have dramatically reduced B-cell populations suggesting that Il2rg is more critical for B-cell development in mice than in humans. Patients with severe combined immunodeficiency (SCID) phenotype due to IL7R mutations (see Puel & Leonard 2000), or a partial deficiency of IL7R (Roifman et al. 2000) have markedly reduced circulating T cells, but normal levels of peripheral blood B cells and NK cells, similar to the phenotype of IL2RG mutations, highlighting a requirement for IL7 in T cell lymphopoiesis. It has been suggested that IL7 is essential for murine, but not human B cell development, but recent studies indicate that IL7 is essential for human B cell production from adult bone marrow and that IL7-induced expansion of the progenitor B cell compartment is increasingly critical for human B cell production during later stages of development (Parrish et al. 2009). IL7 has been shown to induce rapid and dose-dependent tyrosine phosphorylation of JAKs 1 and 3, and concomitantly tyrosine phosphorylation and DNA-binding activity of STAT5a/b (Foxwell et al. 1995). IL7R was shown to directly induce the activation of JAKs and STATs by van der Plas et al. (1996). Jak1 and Jak3 knockout mice displayed severely impaired thymic development, further supporting their importance in IL7 signaling (Rodig et al. 1998, Nosaka et al. 1995). The role of STAT5 in IL7 signaling has been studied largely in mouse models. Tyr449 in the cytoplasmic domain of IL7RA is required for T-cell development in vivo and activation of JAK/STAT5 and PI3k/Akt pathways (Jiang et al. 2004, Pallard et al. 1999). T-cells from an IL7R Y449F knock-in mouse did not activate STAT5 (Osbourne et al. 2007), indicating that IL7 regulates STAT5 activity via this key tyrosine residue. STAT5 seems to enhance proliferation of multiple cell lineages in mouse models but it remains unclear whether STAT5 is required solely for survival signaling or also for the induction of proliferative activity (Kittipatarin & Khaled, 2007). The model for IL7 receptor signaling is believed to resemble that of other Gc family cytokines, based on detailed studies of the IL2 receptor, where IL2RB binds constitutively to JAK1 while JAK3 is pre-associated uniquely with the IL2RG chain. Extending this model to IL7 suggests a similar series of events: IL7R constitutively associated with JAK1 binds IL7, the resulting trimer recruits IL2RG:JAK3, bringing JAK1 and JAK3 into proximity. The association of both chains of the IL7 receptor orients the cytoplasmic domains of the receptor chains so that their associated kinases (Janus and phosphatidylinositol 3-kinases) can phosphorylate sequence elements on the cytoplasmic domains (Jiang et al. 2005). JAKs have low intrinsic enzymatic activity, but after mutual phosphorylation acquire much higher activity, leading to phosphorylation of the critical Y449 site on IL7R. This site binds STAT5 and possibly other signaling adapters, they in turn become phosphorylated by JAK1 and/or JAK3. Phosphorylated STATs translocate to the nucleus and trigger the transcriptional events of their target genes. The role of the PI3K/AKT pathway in IL7 signaling is controversial. It is a potential T-cell survival pathway because in many cell types PI3K signaling regulates diverse cellular functions such as cell cycle progression, transcription, and metabolism. The ERK/MAPK pathway does not appear to be involved in IL7 signaling (Crawley et al. 1996). It is not clear how IL7 influences cell proliferation. In the absence of a proliferative signal such as IL7 or IL3, dependent lymphocytes arrest in the G0/G1 phase of the cell cycle. To exit this phase, cells typically activate specific G1 Cyclin-dependent kinases/cyclins and down regulate cell cycle inhibitors such as Cyclin-dependent kinase inhibitor 1B (Cdkn1b or p27kip1). There is indirect evidence suggesting a possible role for IL7 stimulated activation of PI3K/AKT signaling, obtained from transformed cell lines and thymocytes, but not confirmed by observations using primary T-cells (Kittipatarin & Khaled, 2007). IL7 withdrawal results in G1/S cell cycle arrest and is correlated with loss of cdk2 activity (Geiselhart et al. 2001), both events which are known to be regulated by the dephosphorylating activity of Cdc25A. Expression of a p38 MAPK-resistant Cdc25A mutant in an IL-7-dependent T-cell line as well as in peripheral, primary T-cells was sufficient to sustain cell survival and promote cell cycling for several days in the absence of IL7 (Khaled et al. 2005). Cdkn1b is a member of the CIP/KIP family of cyclin-dependent cell cycle inhibitors (CKIs) that negatively regulates the G1/S transition. In IL7 dependent T-cells, the expression of Cdkn1b was sufficient to cause G1 arrest in the presence of IL7. Withdrawal of IL7 induced the upregulation of Cdkn1b and arrested cells in G1 while siRNA knockout of Cdkn1b enhanced cell cycle progression. However, adoptive transfer of Cdkn1b-deficient lymphocytes into IL7 deficient mice indicated that loss of Cdkn1b could only partially compensate for the IL7 signal needed by T-cells to expand in a lymphopenic environment (Li et al. 2006), so though Cdkn1b may be involved in negative regulation of the cell cycle through an effect on cdk2 activity, its absence is not sufficient to fully induce cell cycling under lymphopenic conditions."
BMGC_PW0269,BMG_PW0908,"Interleukin-12 family members are heterodimeric cytokines produced by antigen-presenting cells. The signaling they initiate triggers the Jak-Stat intracellular cascade and plays important roles in the regulation of T helper (Th) cell differentiation. [PMID:20885915, Reactome:R-HSA-447115]",,"Interleukin-12 (IL-12) is a heterodimer of interleukin-12 subunit alpha (IL12A, IL-12p35) and interleukin-12 subunit beta (IL12B, IL-12p40). It is a potent immunoregulatory cytokine involved in the generation of cell mediated immunity to intracellular pathogens. It is produced by antigen presenting cells, including dendritic cells, macrophages/monocytes, neutrophils and some B cells (D'Andrea et al. 1992, Kobayashi et al.1989, Heufler et al.1996). It enhances the cytotoxic activity of natural killer (NK) cells and cytotoxic T cells, stimulating proliferation of activated NK and T cells and induces production of interferon gamma (IFN gamma) by these cells (Stern et al. 1990). IL-12 also plays an important role in immunomodulation by promoting cell mediated immunity through induction of a class 1 T helper cell (Th1) immune response. IL-12 may contribute to immunopathological conditions such as rheumatoid arthritis (McIntyre et al. 1996). The receptor for IL-12 is a heterodimer of IL-12Rbeta1 (IL12RB1) and IL-12Rbeta2 (IL12RB2), both highly homologous to Interleukin-6 receptor subunit beta (IL6ST,gp130). Each has an extracellular ligand binding domain, a transmembrane domain and a cytosolic domain containing box 1 and box 2 sequences that mediate binding of Janus family tyrosine kinases (JAKs). IL-12 binding is believed to bring about the heterodimerization and generation of a high affinity receptor complex capable of signal transduction. In this model, receptor dimerization leads to juxtaposition of the cytosolic domains and subsequent tyrosine phosphorylation and activation of JAK2 and TYK2. These activated kinases, in turn, tyrosine phosphorylate and activate several members of the signal transducer and activator of transcription (STAT) family, mainly STAT4, while also STAT1, STAT3 and STAT5 have been reported to be activated (Bacon et al. 1995, Jacobson et al. 1995, Yu et al. 1996, Gollob et al.1995). The STATs translocate to the nucleus to activate transcription of several genes, including IFN gamma. The production of IFN gamma has a pleiotropic effect in the cell, stimulating production of molecules important to cell mediated immunity. In particular, IFN gamma stimulates production of more IL-12 and sets up a positive regulation loop between IL-12 signaling and IFN gamma (Chan et al. 1991). The importance of IL-12 for this loop is demonstrated by IL-12 and STAT4 knockout mice that are severely compromised in IFN-gamma production (Kaplan et al. 1996; Magram et al. 1996), as well as by patients with IL12B mutations that are severely compromised in IFN-gamma production (Altare et al.1998)."
BMGC_PW0270,BMG_PW0956,"Ceramide signaling can act as a lipid second messenger or as a mediator of various cellular signaling pathways by promoting receptor clustering. The pathway plays important roles in apoptosis. [KEGG:05212, PID:200119, PMID:20607622, Reactome:R-HSA-193681]","Infiltrating ductal adenocarcinoma is the most common malignancy of the pancreas. When most investigators use the term 'pancreatic cancer' they are referring to pancreatic ductal adenocarcinoma (PDA). Normal duct epithelium progresses to infiltrating cancer through a series of histologically defined precursors (PanINs). The overexpression of HER-2/neu and activating point mutations in the K-ras gene occur early, inactivation of the p16 gene at an intermediate stage, and the inactivation of p53, SMAD4, and BRCA2 occur relatively late. Activated K-ras engages multiple effector pathways. Although EGF receptors are conventionally regarded as upstream activators of RAS proteins, they can also act as RAS signal transducers via RAS-induced autocrine activation of the EGFR family ligands. Moreover, PDA shows extensive genomic instability and aneuploidy. Telomere attrition and mutations in p53 and BRCA2 are likely to contribute to these phenotypes. Inactivation of the SMAD4 tumour suppressor gene leads to loss of the inhibitory influence of the transforming growth factor-beta signalling pathway.","In certain cell types, ligand binding to p75NTR leads to ceramide production, which can mediate either cell survival (e.g. in noecotical subplate neurons) or apoptosis (e.g. in oligodendrocytes). Low levels of ceramide are also able to stimulate axonal outgrowth in hippocampal neurons."
BMGC_PW0271,BMG_PW0957,"The signaling pathway initiated by light-induced isomerization of 11-cis retinal and subsequent activation of its photoreceptors in rods and cones. [GO:0007603, KEGG:04744, PMID:18514002, PMID:22074921, Reactome:R-HSA-2187338]","Phototransduction is a biochemical process by which the photoreceptor cells generate electrical signals in response to captured photons. The vertebrate cascade starts with the absorption of photons by the photoreceptive pigments, the rhodopsins, which consist of a membrane embedded chromophore, 11-cis-retinal, and a G-protein-coupled receptor, opsin. The photon isomerizes 11-cis-retinal to all-trans-retinal which induces a structural change that activates the opsin. This triggers hydrolysis of cGMP by activating a transducinphosphodiesterase 6 (PDE6) cascade, which results in closure of the cGMP-gated cation channels (CNG) in the plasma membrane and membrane hyperpolarization. The hyperpolarization of the membrane potential of the photoreceptor cell modulates the release of neurotransmitters to downstream cells. Recovery from light involves the deactivation of the light- activated intermediates: photolyzed rhodopsin is phosphorylated by rhodopsin kinase (RK) and subsequently capped off by arrestin; GTP-binding transducin alpha subunit deactivates through a process that is stimulated by RGS9.","Visual phototransduction is the process by which photon absorption by visual pigment molecules in photoreceptor cells is converted to an electrical cellular response. The events in this process are photochemical, biochemical and electrophysiological and are highly conserved across many species. This process occurs in two types of photoreceptors in the retina, rods and cones. Each type consists of two parts, the outer segment which detects a photon signal and the inner segment which contains the necessary machinery for cell metabolism. Each type of cell functions differently. Rods are very light sensitive but their flash response is slow so they work best in twilight conditions but are not good at detecting objects moving quickly. Cones are less light-sensitive and have a fast flash response so they work best in daylight conditions and are better at detecting fast moving objects than rods. The visual pigment consists of a chromophore (11-cis-retinal, 11cRAL, A1) covalently attached to a GPCR opsin family member. The linkage is via a Schiff base forming retinylidene protein. Upon photon absorption, 11cRAL isomerises to all-trans retinal (atRAL), changing the conformation of opsin to an activated form which can activate the regulatory G protein transducin (Gt). The alpha subunit of Gt activates phosphodiesterase which hydrolyses cGMP to 5'-GMP. As high level of cGMP keep cGMP-gated sodium channels open, the lowering of cGMP levels closes these channels which causes hyperpolarization of the cell and subsequently, closure of voltage-gated calcium channels. As calcium levels drop, the level of the neurotransmitter glutamate also drops causing depolarization of the cell. This effectively relays the light signal to postsynaptic neurons as electrical signal (Burns & Pugh 2010, Korenbrot 2012, Pugh & Lamb 1993). 11cRAL cannot be synthesised in vertebrates. Vitamin A from many dietary sources is the precursor for 11cRAL. It is taken from food in the form of esters such as retinyl acetate or palmitate or one of four caretenoids (alpha-carotene, beta-carotene, gamma-carotene and beta-cryptoxanthin). Retinoids are transported from the gut to be stored in liver, until required by target organs such as the eye (Harrison & Hussain 2001, Harrison 2005). In the eye, in the form 11cRAL, it is used in the retinoid (visual) cycle to initiate phototransduction and for visual pigment regeneration to ready the photoreceptor for the next phototransduction event (von Lintig 2012, Blomhoff & Blomhoff 2006, von Lintig et al. 2010, D'Ambrosio et al. 2011, Wang & Kefalov 2011, Kefalov 2012, Wolf 2004)."
BMGC_PW0272,BMG_PW0962,"The interleukin-3, interleukin 5 and granulocyte-macrophage colony-stimulating factor family of hemopoietic cytokines mediate overlapping and distinct signals. Collectively they regulate the production and activation of hemopoietic cells. [PMID:19436055, Reactome:R-HSA-512988]",,"The Interleukin-3 (IL-3), IL-5 and Granulocyte-macrophage colony stimulating factor (GM-CSF) receptors form a family of heterodimeric receptors that have specific alpha chains but share a common beta subunit, often referred to as the common beta (Bc). Both subunits contain extracellular conserved motifs typical of the cytokine receptor superfamily. The cytoplasmic domains have limited similarity with other cytokine receptors and lack detectable catalytic domains such as tyrosine kinase domains. IL-3 is a 20-26 kDa product of CD4+ T cells that acts on the most immature marrow progenitors. IL-3 is capable of inducing the growth and differentiation of multi-potential hematopoietic stem cells, neutrophils, eosinophils, megakaryocytes, macrophages, lymphoid and erythroid cells. IL-3 has been used to support the proliferation of murine cell lines with properties of multi-potential progenitors, immature myeloid as well as T and pre-B lymphoid cells (Miyajima et al. 1992). IL-5 is a hematopoietic growth factor responsible for the maturation and differentiation of eosinophils. It was originally defined as a T-cell-derived cytokine that triggers activated B cells for terminal differentiation into antibody-secreting plasma cells. It also promotes the generation of cytotoxic T-cells from thymocytes. IL-5 induces the expression of IL-2 receptors (Kouro & Takatsu 2009). GM-CSF is produced by cells (T-lymphocytes, tissue macrophages, endothelial cells, mast cells) found at sites of inflammatory responses. It stimulates the growth and development of progenitors of granulocytes and macrophages, and the production and maturation of dendritic cells. It stimulates myeloblast and monoblast differentiation, synergises with Epo in the proliferation of erythroid and megakaryocytic progenitor cells, acts as an autocrine mediator of growth for some types of acute myeloid leukemia, is a strong chemoattractant for neutrophils and eosinophils. It enhances the activity of neutrophils and macrophages. Under steady-state conditions GM-CSF is not essential for the production of myeloid cells, but it is required for the proper development of alveolar macrophages, otherwise, pulmonary alvelolar proteinosis (PAP) develops. A growing body of evidence suggests that GM-CSF plays a key role in emergency hematopoiesis (predominantly myelopoiesis) in response to infection, including the production of granulocytes and macrophages in the bone marrow and their maintenance, survival, and functional activation at sites of injury or insult (Hercus et al. 2009). All three receptors have alpha chains that bind their specific ligands with low affinity (de Groot et al. 1998). Bc then associates with the alpha chain forming a high affinity receptor (Geijsen et al. 2001), though the in vivo receptor is likely be a higher order multimer as recently demonstrated for the GM-CSF receptor (Hansen et al. 2008). The receptor chains lack intrinsic kinase activity, instead they interact with and activate signaling kinases, notably Janus Kinase 2 (JAK2). These phosphorylate the common beta subunit, allowing recruitment of signaling molecules such as Shc, the phosphatidylinositol 3-kinases (PI3Ks), and the Signal Transducers and Activators of Transcription (STATs). The cytoplasmic domain of Bc has two distinct functional domains: the membrane proximal region mediates the induction of proliferation-associated genes such as c-myc, pim-1 and oncostatin M. This region binds multiple signal-transducing proteins including JAK2 (Quelle et al. 1994), STATs, c-Src and PI3 kinase (Rao and Mufson, 1995). The membrane distal domain is required for cytokine-induced growth inhibition and is necessary for the viability of hematopoietic cells (Inhorn et al. 1995). This region interacts with signal-transducing proteins such as Shc (Inhorn et al. 1995) and SHP and mediates the transcriptional activation of c-fos, c-jun, c-Raf and p70S6K (Reddy et al. 2000). Figure reproduced by permission from Macmillan Publishers Ltd: Leukemia, WL Blalock et al. 13:1109-1166, copyright 1999. Note that residue numbering in this diagram refers to the mature Common beta chain with signal peptide removed."
BMGC_PW0273,BMG_PW0998,"Those metabolic reactions involving the fat-soluble vitamin A and its metabolites. Vitamin A, retinol and vitamin A activities of metabolites such as retinal and retinoic acids are essential for visual transduction as well as for neuro and immune system functions and epithelial differentiation. Plants and microorganisms can synthesize vitamin A de novo while higher organisms derive it from diet as precursors of carotenoids or retinyl esters. [GO:0001523, PMID:21554983, Reactome:R-HSA-975634]",,"Vitamin A (all-trans-retinol) must be taken up, either as carotenes from plants, or as retinyl esters from animal food. The most prominent carotenes are alpha-carotene, lycopene, lutein, beta-cryptoxanthine, and especially beta-carotene. After uptake they are mostly broken down to retinal. Retinyl esters are hydrolysed like other fats. In enterocytes, retinoids bind to retinol-binding protein (RBP). Transport from enterocytes to the liver happens via chylomicrons (Harrison & Hussain 2001, Harrison 2005)."
BMGC_PW0274,BMG_PW1003,"The series of reactions within a cell required to convert absorbed photons into molecular signals. [GO:0007602, Reactome:R-HSA-2514856]",,"The visual pigment (rhodopsin in rods) consists of an 11-cis-retinal (11cRAL) chromophore covalently attached to a GPCR opsin family member via a Schiff base linkage. Upon photon absorption, 11cRAL isomerizes to all trans retinal (atRAL), changing the conformation of opsin to a form that can activate the regulatory G protein transducin (Gt). The alpha subunit of Gt activates phosphodiesterase which hydrolyses cGMP to 5'-GMP. A high level of cGMP keeps cGMP-gated cation channels open, so lower cGMP levels close these channels and hyperpolarize the cell. The hyperpolarization spreads passively to the synapse located at the opposite end of the rod, where it subsequently closes voltage-gated calcium channels. Vesicular release of the neurotransmitter glutamate subsides as the intracellular calcium levels drop. This diminution of neurotransmitter release relays the light signal to postsynaptic neurons. The events below describe activation, inactivation, recovery and regulation of the phototransduction cascade in rods (Burns & Pugh 2010, Korenbrot 2012, Smith 2010)."
BMGC_PW0275,BMG_PW1004,"Those metabolic reactions involving ascorbic acid, known as vitamin C, a water-soluble vitamin. Vitamin C is an essential antioxidant that is derived from glucose. Unlike many animals, humans do not have the ability to produce it. [GO:0019852, https://en.wikipedia.org/wiki/Vitamin_C wikipedia, Reactome:R-HSA-196836]",,"Vitamin C (ascorbate) is an antioxidant and a cofactor in reactions catalyzed by Cu+-dependent monooxygenases and Fe++-dependent dioxygenases. Many mammals can synthesize ascorbate de novo; humans and other primates cannot due to an evolutionarily recent mutation in the gene catalyzing the last step of the biosynthetic pathway. Reactions annotated here mediate the uptake of ascorbate and its fully oxidized form, dehydroascorbate (DHA) by cells, and the reduction of DHA and monodehydroascorbate to regenerate ascorbate (Linster and Van Schaftingen 2007)."
BMGC_PW0276,BMG_PW1005,"Those metabolic reactions involving niacin, also known as nicotinate, vitamin B3 or vitamin PP - a water-soluble vitamin. Niacin represents an essential nutrient and is also a precursor of NAD through a salvage pathway. Niacin is among the few vitamins humans can synthesize. [GO:1901847, https://en.wikipedia.org/wiki/Niacin wikipedia, KEGG:00760, Reactome:R-HSA-196807, SMP:00048]",,"Nicotinate (niacin) and nicotinamide are precursors of the coenzymes nicotinamide-adenine dinucleotide (NAD+) and nicotinamide-adenine dinucleotide phosphate (NADP+). When NAD+ and NADP+ are interchanged in a reaction with their reduced forms, NADH and NADPH respectively, they are important cofactors in several hundred redox reactions. Nicotinate is synthesized from 2-amino-3-carboxymuconate semialdehyde, an intermediate in the catabolism of the essential amino acid tryptophan (Magni et al. 2004)."
BMGC_PW0277,BMG_PW1006,"Those metabolic reactions involving vitamin D - a fat-soluble vitamin. Vitamin D represents a group of fat-soluble compounds that can be synthesized from cholesterol and exposure to sunlight. In view of the latter source, it is not considered a true vitamin. One of its metabolites, calcitriol, acts in a hormone-like manner as a signaling molecule. [GO:0042359, https://en.wikipedia.org/wiki/Vitamin_D wikipedia, Reactome:R-HSA-196791]",,"Vitamin D3 (VD3, cholecalciferol) is a steroid hormone that principally plays roles in regulating intestinal calcium absorption and in bone metabolism. It is obtained from the diet and produced in the skin by photolysis of 7-dehydrocholesterol and released into the bloodstream. Very few foods (eg. oily fish, mushrooms exposed to sunlight and cod liver oil) are natural sources of vitamin D. A small number of countries in the world artificially fortify a few foods with vitamin D. The metabolites of vitamin D are carried in the circulation bound to a plasma protein called vitamin D binding protein (GC) (for review see Delanghe et al. 2015, Chun 2012). Vitamin D undergoes two subsequent hydroxylations to form the active form of the vitamin, 1-alpha, 25-dihydroxyvitamin D (1,25(OH)2D). The first hydroxylation takes place in the liver followed by subsequent transport to the kidney where the second hydroxylation takes place. 1,25(OH)2D acts by binding to nuclear vitamin D receptors (Neme et al. 2017) and it has been estimated that upwards of 2000 genes are directly or indirectly regulated which are involved in calcium homeostasis, immune responses, cellular growth, differentiation and apoptosis (Hossein-nezhad et al. 2013, Hossein-nezhad & Holick 2013). Inactivation of 1,25(OH)2D occurs via C23/C24 oxidation catalysed by cytochrome CYP24A1 enzyme (Christakos et al. 2016)."
BMGC_PW0278,BMG_PW1009,"Retinoic acid, a vitamin A-derived metabolite, plays important roles in development and cell differentiation. All-trans retinoic acid (RA) binds to nuclear RA (RARs) and X (RXRs) receptor subtypes that once activated act as transcription factors. [GO:0048384, PMID:22020178, PMID:22318625, Reactome:R-HSA-5362517]",,"Vitamin A (retinol) can be metabolised into active retinoid metabolites that function either as a chromophore in vision or in regulating gene expression transcriptionally and post-transcriptionally. Genes regulated by retinoids are essential for reproduction, embryonic development, growth, and multiple processes in the adult, including energy balance, neurogenesis, and the immune response. The retinoid used as a cofactor in the visual cycle is 11-cis-retinal (11cRAL). The non-visual cycle effects of retinol are mediated by retinoic acid (RA), generated by two-step conversion from retinol (Napoli 2012). All-trans-retinoic acid (atRA) is the major activated metabolite of retinol. An isomer, 9-cis-retinoic acid (9cRA) has biological activity, but has not been detected in vivo, except in the pancreas. An alternative route involves BCO1 cleavage of carotenoids into retinal, which is then reduced into retinol in the intestine (Harrison 2012). The two isomers of RA serve as ligands for retinoic acid receptors (RAR) that regulate gene expression. (Das et al. 2014). RA is catabolised to oxidised metabolites such as 4-hydroxy-, 18-hydroxy- or 4-oxo-RA by CYP family enzymes, these metabolites then becoming substrates for Phase II conjugation enzymes (Ross & Zolfaghari 2011)."
BMGC_PW0279,BMG_PW1013,"Altered immune system responses can be grouped into four categories: malignancy, immunodeficiency, hypersensitivity and autoimmunity. [Reactome:R-HSA-5260271]",,"The immune system is a complex network of the biological processes that provide defense mechanisms during infection or in response to an intrinsic danger signal. Compromised immune response may present itself as either overactivity or underactivity of the immune system leading to a broad spectrum of clinical phenotypes that can be categorized into four main groups - autoimmunity, immunodeficiency (ID) with a greater susceptibility to infectious diseases, hypersensitivity to compounds that are usually not harmful and malignancy. Several host conditions may cause the dysfunctional immunity. Among them are inherited and somatic mutations found in the components of immune signaling pathways. In addition to genetic defects, infection with pathogen such as human immunodeficiency virus (HIV), or interaction of immune cells with immunosuppressive drugs result in non-genetic immunodeficiencies. Age-associated alterations in immunity may also contribute to pathogenesis of immunodeficiency . The Reactome module represents selected defects of the immune system and provides a short description of their clinical phenotypes. The module also describes functional features of defective molecules by both providing a published source for experimental functional analysis data and linking to the corresponding normal process within the Reactome database."
BMGC_PW0280,BMG_PW1023,"Infectious diseases are caused by pathogens that have gained access to the host organism and have managed to avoid the host defense mechanisms while taking over some of the host pathways. [http://www.onelook.com OneLook, Reactome:R-HSA-5663205]",,"Infectious diseases are ones due to the presence of pathogenic microbial agents in human host cells. Processes annotated in this category include bacterial, viral and parasitic infection pathways. Bacterial infection pathways currently include some metabolic processes mediated by intracellular Mycobacterium tuberculosis, the actions of clostridial, anthrax, and diphtheria toxins, and the entry of Listeria monocytogenes into human cells. Viral infection pathways currently include the life cycles of SARS-CoV viruses, influenza virus, HIV (human immunodeficiency virus), and human cytomegalovirus (HCMV). Parasitic infection pathways currently include Leishmania infection-related pathways. Fungal infection pathways and prion diseases have not been annotated."
BMGC_PW0281,BMG_PW1025,"Prolonged use of cocaine results in cardiovascular and brain damage. Cocaine is thought to bind to the dopamine reuptake transporter thus blocking the reuptake of dopamine into nerve terminals. The resulting higher concentration of dopamine in synapses leads to overactivation of dopamine receptors such as D1 and of signaling pathways downstream of it overall believed to be critical in mediating the behavioral responses to cocaine. [http://www.onelook.com OneLook, KEGG:map05030]","Drug addiction is a chronic, relapsing disorder in which compulsive drug-seeking and drug-taking behavior persists despite serious negative consequences.There is strong evidence that the dopaminergic system that projects from the ventral tegmental area (VTA) of the midbrain to the nucleus accumbens (NAc), and to other forebrain sites, is the major substrate of reward and reinforcement for both natural rewards and addictive drugs. Cocaine binds strongly to the dopamine-reuptake transporter, preventing the reuptake of dopamine into the nerve terminal. Because of this blocking effect, dopamine remains at high concentrations in the synapse and continues to affect adjacent neurons, producing the characteristic cocaine ""high."" Activated D1 receptor activates the PKA signaling pathway, and this pathway plays a critical role in mediating the behavioral responses to cocaine administration. Cocaine-induced neuroadaptations, including dopamine depletion, may underlie craving and hedonic dysregulation.",
BMGC_PW0282,BMG_PW1027,"Morphine, an effective pain killer drug, can also be extremely addictive. Activation of dopamine neurons and reduction of inhibitory synaptic transmission might be associated with the effects or morphine. Changes in neuronal responses and communication may underlie the addictive behavior. [http://www.onelook.com OneLook, KEGG:map05032]","Morphine is an alkaloid from the plant extracts of opium poppy. Although morphine is highly effective for the treatment of pain, it is also known to be intensely addictive. We now know that the most important brain-reward circuit involves dopamine (DA) -containing neurons in the ventral tegmental area (VTA) of the midbrain and their target areas in the limbic forebrain, in particular, the nucleus accumbens (NAc) and frontal regions of cerebral cortex. Morphine can cause indirect excitation of VTA dopamine neurons by reducing inhibitory synaptic transmission mediated by GABAergic neurons. The chronic use of morphine is characterized by adaptive changes in neurons and neuronal communication; such adaptations (e.g., 'superactivation' of adenylyl cyclase) must underlie altered behaviour associated with morphine dependence and withdrawal syndrome, as well as drug-induced craving and relapse to drug use.",
BMGC_PW0283,BMG_PW1028,"Nicotine, like the other addictive substances, impacts on the dopaminergic and mesolimbic reward circuitries. Nicotine is also a ligand for the nicotinic acetylcholine receptors which are ligand-gated ion channels. [http://www.onelook.com OneLook, KEGG:map05033]","Nicotine is one of the main psychoactive ingredients in tobacco that contributes to the harmful tobacco smoking habit. A common feature of addictive drugs, including nicotine, is that they increase dopamine (DA) release in the nucleus accumbens (NAc). The principal dopaminergic projections to NAc arise from neurons in the ventral tegmental area (VTA). In the VTA, alpha6- and alpha4beta2-containing nAChRs (alpha6*-AChRs and alpha4beta2*-AChRs, respectively) are located on GABAergic terminals and provide inhibitory inputs onto DAergic neuons, while alpha7*-nAChRs are located on glutamatergic terminals and activation of these receptors enhances glutamate release and increases excitability of DAergic neurons. Nicotine acts as an agonist to activate and desensitize these nicotinic acetylcholine receptors (nAChRs). After a short exposure to nicotine, alpha6*- and alpha4beta2*- nAChRs on GABAergic afferents are desensitized, decreasing GABA release and decreasing local inhibition of DA neurons. But the alpha7*-nAChRs on glutamatergic afferents remain active and enhance glutamate excitation of the DA neurons, leading to increased DA release in the NAc -and so facilitate the reinforcing effects of nicotine.",
BMGC_PW0284,BMG_PW1029,"The mechanisms of alcohol dependence, or alcoholism, are not well understood. Like in the case of other substances of abuse, alcohol may lead to stimulation of dopamine release and overactivation of dopamine-related circuitries. [http://www.onelook.com OneLook, KEGG:map05034]","Alcoholism, also called dependence on alcohol (ethanol), is a chronic relapsing disorder that is progressive and has serious detrimental health outcomes. As one of the primary mediators of the rewarding effects of alcohol, dopaminergic ventral tegmental area (VTA) projections to the nucleus accumbens (NAc) have been identified. Acute exposure to alcohol stimulates dopamine release into the NAc, which activates D1 receptors, stimulating PKA signaling and subsequent CREB-mediated gene expression, whereas chronic alcohol exposure leads to an adaptive downregulation of this pathway, in particular of CREB function. The decreased CREB function in the NAc may promote the intake of drugs of abuse to achieve an increase in reward and thus may be involved in the regulation of positive affective states of addiction. PKA signaling also affects NMDA receptor activity and may play an important role in neuroadaptation in response to chronic alcohol exposure.",
BMGC_PW0285,BMG_PW1030,"Arrhythmogenic right ventricular cardiomyopathy (ARVC) represents an inherited heart muscle condition leading to arrhythmia and heart failure that could results in death. Mutations in several genes and disruption of associated pathways have been implicated in the condition. [http://www.onelook.com OneLook, KEGG:map05412]","Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease that may result in arrhythmia, heart failure, and sudden death. The hallmark pathological findings are progressive myocyte loss and fibrofatty replacement, with a predilection for the right ventricle. A number of genetic studies have identified mutations in various components of the cardiac desmosome that have important roles in the pathogenesis of ARVC. Disruption of desmosomal function by defective proteins might lead to death of myocytes under mechanical stress. The myocardial injury may be accompanied by inflammation. Since regeneration of cardiac myocytes is limited, repair by fibrofatty replacement occurs. Several studies have implicated that desmosome dysfunction results in the delocalization and nuclear translocation of plakoglobin. As a result, competition between plakoglobin and beta-catenin will lead to the inhibition of Wnt/beta-catenin signaling, resulting in a shift from a myocyte fate towards an adipocyte fate of cells. The ryanodine receptor plays a crucial part in electromechanical coupling by control of release of calcium from the sarcoplasmic reticulum into the cytosol. Therefore, defects in this receptor could result in an imbalance of calcium homeostasis that might trigger cell death.",
BMGC_PW0286,BMG_PW1031,"Dilated cardiomyopathy (DCM) is a condition in which the heart is weakened and enlarged resulting in inefficient blood pumping. Although mostly occurring in adults, it can also affect children. [http://www.onelook.com OneLook, KEGG:map05414]","Dilated cardiomyopathy (DCM) is a heart muscle disease characterised by dilation and impaired contraction of the left or both ventricles that results in progressive heart failure and sudden cardiac death from ventricular arrhythmia. Genetically inherited forms of DCM (""familial"" DCM) have been identified in 25-35% of patients presenting with this disease, and the inherited gene defects are an important cause of ""familial"" DCM. The pathophysiology may be separated into two categories: defects in force generation and defects in force transmission. In cases where an underlying pathology cannot be identified, the patient is diagnosed with an ""idiopathic"" DCM. Current hypotheses regarding causes of ""idiopathic"" DCM focus on myocarditis induced by enterovirus and subsequent autoimmune myocardium impairments. Antibodies to the beta1-adrenergic receptor (beta1AR), which are detected in a substantial number of patients with ""idiopathic"" DCM, may increase the concentration of intracellular cAMP and intracellular Ca2+, a condition often leading to a transient hyper-performance of the heart followed by depressed heart function and heart failure.",
BMGC_PW0287,BMG_PW1032,"Myocarditis is a condition associated with inflammation of the heart muscle that can have both infectious and non-infectious etiologies, with the former being the primary cause. Viral proteins, once inside the host cells, interfere with the function of host gene and they can either avoid or appropriate host pathways. [http://www.onelook.com OneLook, KEGG:map05416]","Myocarditis is a cardiac disease associated with inflammation and injury of the myocardium. It results from various etiologies, both noninfectious and infectious, but coxsackievirus B3 (CVB3) is still considered the dominant etiological agent. Myocarditis may be caused by direct cytopathic effects of virus, a pathologic immune response to persistent virus, or autoimmunity triggered by the viral infection. The virus enters the myocyte through internalization of the coxsackie-adenoviral receptor (CAR) and its coreceptor, decay-accelerating factor (DAF). Viral proteases cleave various proteins in the host cell. One example is viral protease 2A, which cleaves eukaryote initiation factor 4G (eIF4G) and the dystrophin protein, resulting in a complete shutdown of cap-dependent RNA translation and cytoskeletal destruction in infected cardiomyocytes, respectively. CVB3 also cleaves the member of the Bcl-2 family Bid, leading to apoptosis. CVB3 infection also induces the cleavage of cyclin D protein through a proteasome-dependent pathway, leading to the host cell-growth arrest. Viral infection and necrosis of myocytes may lead to the release of intracellular antigens, resulting in activation of self-reactive T cells. CVB infection is a significant cause of dilated cardiomyopathy (DCM) as well as myocarditis. Epidemiologically, myocarditis underlies a significant portion of patients with DCM.",
BMGC_PW0288,BMG_PW1033,"Maturity onset diabetes of the young (MODY) represents any of a number of hereditary, monogenic forms of diabetes caused by mutations in several genes. [http://www.onelook.com OneLoook, KEGG:map04950]","About 2-5% of type II diabetic patients suffer from a monogenic disease with autosomal dominant inheritance. This monogenic form of type II diabetes is called maturity onset diabetes of the young (MODY).             We now know that MODY is caused by heterozygous mutations in at least five genes encoding transcription factors: HNF4alpha (MODY1), HNF1alpha (MODY3), PDX1 (MODY4), HNF1beta (MODY5) and NEUROD1 (MODY6). MODY2, which is so far the only subtype not related to a transcription factor, is caused by mutations in the glucokinase gene. Mutations of MODY transcription factor genes lead to abnormal expression of genes involved in pancreatic islet development and metabolism.",
BMGC_PW0289,BMG_PW1034,"Vibrio cholerae disease is an infection of the small intestine resulting in dehydration and electrolyte imbalance which in some cases can cause death. Cholera toxin, is one the main virulence factors of the Gram-negative Vibrio cholerae bacterium which, together with other virulence factors can invade the host. [http://www.onelook.com OneLook, KEGG:map05110]","Cholera toxin (CTX) is one of the main virulence factors of Vibrio cholerae. Once secreted, CTX B-chain (CTXB) binds to ganglioside GM1 on the surface of the host's cells. After binding takes place, the entire CTX complex is carried from plasma membrane (PM) to endoplasmic reticulum (ER). In the ER, the A-chain (CTXA) is recognized by protein disulfide isomerase (PDI), unfolded, and delivered to the membrane where the membrane-associated ER-oxidase, Ero1, oxidizes PDI to release the CTXA into the protein-conducting channel, Sec61. CTXA is then retro-translocated to the cytosol and induces water and electrolyte secretion by increasing cAMP levels via adenylate cyclase (AC) to exert toxicity.             Other than CTX, Vibrio cholerae generates several toxins that are perilous to eukaryotic cells. Zonula occludens toxin (ZOT) causes tight junction disruption through protein kinase C-dependent actin polymerization. RTX toxin (RtxA) causes actin depolymerization by covalently cross-linking actin monomers into dimers, trimers, and higher multimers. Vibrio cholerae cytolysin (VCC) is an important pore-forming toxin. The assembly of VCC anion channels in cells cause vacuolization and lysis.",
BMGC_PW0290,BMG_PW1035,"Salmonella, a Gram-negative bacterium of which  many species exist, in humans can cause gastroenteritis or the more severe typhoid fever. Salmonella enters the host via the digestive tract; bacteria that escape the host defense machinery can survive and replicate in Salmonella-containing vacuole (SCV) whose maturation they control. [http://www.onelook.com OneLook, KEGG:map05132]","Salmonella infection usually presents as a self-limiting gastroenteritis or the more severe typhoid fever and bacteremia. The common disease-causing Salmonella species in human is a single species, Salmonella enterica, which has numerous serovars.             Following intestinal colonization Salmonella inject effector proteins into the host cells using a type III secretion system (T3SS), T3SS1. Then a small group of effector proteins induce rearrangement of the actin cytoskeleton resulting in membrane ruffles and rapid internalization of the bacteria.The T3SS2 is responsible for translocating effector proteins that direct Salmonella-containing vacuole (SCV) maturation. The majority of the bacteria are known to survive and replicate in SCV.",
BMGC_PW0291,BMG_PW1036,"The pathogenic Escherichia coli strains EPEC and EHEC (enteropathogenic and enterohemorrhagic E. coli, respectively) can cause severe food poisoning in humans. The non-pathogenic strains are part of the gut normal flora with beneficial contributions for the host. [http://www.onelook.com OneLook, KEGG:map05130]","Enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) are closely related pathogenic strains of Escherichia coli. The hallmark of EPEC/EHEC infections [DS:H00278 H00277] is induction of attaching and effacing (A/E) lesions that damage intestinal epithelial cells. The capacity to form A/E lesions is encoded mainly by the locus of enterocyte effacement (LEE) pathogenicity island. Tir, Map, EspF, EspG are known LEE-encoded effector proteins secreted via the type III secretion system, which is also LEE-encoded, into the host cell. EPEC and EHEC Tir's link the extracellular bacterium to the cell cytoskeleton. Map and EspF are involved in mitochondrion membrane permeabilization. EspG interacts with tubulins and stimulates microtubule destabilization. LEE-encoded adhesin or intimin (Eae) is exported via the general secretory pathway to the periplasm, where it is inserted into the outer membrane. In addition to Tir, two potential host cell-carried intimin receptors, beta1 integrin (ITGB1) and nucleolin (NCL), have so far been identified. The distinguishing feature of EHEC is the elaboration of Shiga-like toxin (Stx). Stx cleaves ribosomal RNA, thereby disrupting protein synthesis and killing the intoxicated epithelial or endothelial cells.",
BMGC_PW0292,BMG_PW1037,"Shigella, a Gram-negative bacterium that is related to Salmonella and to Escherichia coli, is a disease causing agent in humans and primates. Shigellosis, also known as bacillary dysentery or Marlow syndrome is due to colonization of the intestinal epithelium and the subsequent evasion of the host defense machinery and use of host intracellular pathways by the bacteria. [http://www.onelook.com OneLook, KEGG:map05131]","Shigellosis, or bacillary dysentery, is an intestinal infection caused by Shigella, a genus of enterobacteria. Shigella are potential food-borne pathogens that are capable of colonizing the intestinal epithelium by exploiting epithelial-cell functions and circumventing the host innate immune response. During basolateral entry into the host-cell cytoplasm, Shigella deliver a subset of effectors into the host cells through the type III secretion system. The effectors induce membrane ruffling through the stimulation of the Rac1-WAVE-Arp2/3 pathway, enabling bacterial entry into the epithelial cells. During multiplication within the cells, Shigella secrete another subset of effectors. VirG induces actin polymerization at one pole of the bacteria, allowing the bacteria to spread intracellularly and to infect adjacent cells. OspF, OspG and IpaH(9.8) downregulate the production of proinflammatory cytokines such as IL-8, helping bacteria circumvent the innate immune response.",
BMGC_PW0293,BMG_PW1038,"The Gram-negative Bordetella pertusis is the causative agent of pertussis or whooping cough. One of its main virulence factors, pertussis toxin blocks the interaction of Galphai subunit of heterotrimeric G protein with its partner receptors. This results in unrestrained adenylyl cyclase activity and subsequent increased concentration of cAMP which affects normal intracellular signaling. [http://www.onelook.com OneLook, KEGG:map05133]","Pertussis, also known as whooping cough, is an acute respiratory infectious disease caused by a bacteria called Bordetella Pertussis. The characteristic symptoms are paroxysmal cough, inspiratory wheezing and post-tussive vomiting.             Following the inhalation of respiratory secretions from an infected individual, bacteria enter the upper respiratory tract and adhere to epithelial cells. Several adhesion factors have been implicated: the filamentous hemagglutinin (FHA), fimbriae, and pertactin (Prn).             Pertussis toxin (Ptx) and adenylate cyclase toxin (ACT) have been identified so far as major protein toxins of B. pertussis. PTX is a hexameric AB5-type exotoxin. Catalytic A subunit catalyzes the ADP-ribosylation of the Gi subunits of the heterotrimeric G protein, then inhibits multiple downstream pathways. ACT is able to penetrate the cytoplasmic membrane of host cells and becomes activated through the cleavage and the binding of calmodulin (CaM). Activated ACT converts ATP to cyclic AMP and subverts cellular signaling pathways.",
BMGC_PW0294,BMG_PW1039,"Legionella, a pathogenic Gram-negative bacterium that includes species such as legionella pneumophila, causes several respiratory infections of which Legionnaires' disease is potentially fatal. L. pneumophila can grow within lung macrophages and is known to subvert several host pathways. [http://www.onelook.com OneLook, KEGG:map05134]","Legionellosis is a potentially fatal infectious disease caused by the bacterium Legionella pneumophila and other legionella species. Two distinct clinical and epidemiological syndromes are associated with Legionella species: Legionnaires' disease is the more severe form of the infection, which may involve pneumonia, and Pontiac fever is a milder respiratory illness.             The pathogenesis of L. pneumophila is derived from its growth within lung macrophages. One of the L. pneumophila's type IV secretion systems, the Dot/Icm secretion system, is of critical importance for its ability to replicate and to cause disease. The Dot/Icm substrates modulate multiple host cell processes and in particular, redirect trafficking of the L. pneumophila phagosome and mediate its conversion into an ER-derived organelle competent for intracellular bacterial replication. L. pneumophila also manipulates host cell death and survival pathways in a way that allows continued intracellular replication.",
BMGC_PW0295,BMG_PW1040,"Staphylococcus aureus, a Gram-positive bacteria of which there are many species, usually colonizes the skin and mucous membranes of humans and other organisms and are mostly harmless. However, they can also cause a range of infections of which some can be extremely severe. [http://www.onelook.com OneLook, KEGG:map05150]","Staphylococcus aureus can cause multiple forms of infections ranging from superficial skin infections to food poisoning and life-threatening infections. The organism has several ways to divert the effectiveness of the immune system: secreting immune modulating proteins that inhibit complement activation and neutrophil chemotaxis or lysis, modulating the sensitivity to cationic antimicrobial peptides (such as defensin) by increasing the positive net charge of its cytoplasmic membrane, and expression of superantigens that prevent development of a normal immune response or cause an emetic response when ingested.",
BMGC_PW0296,BMG_PW1041,"Mycobacterium tuberculosis is the causative agent of most forms of tuberculosis. Once in the lung, the bacteria interfere with a number of intracellular pathways and processes. [http://www.onelook.com OneLook, KEGG:map05152]","Tuberculosis, or TB, is an infectious disease caused by Mycobacterium tuberculosis. One third of the world's population is thought to be infected with TB. About 90% of those infected result in latent infections, and about 10% of latent infections develop active diseases when their immune system is impaired due to the age, other diseases such as AIDS or exposure to immunosuppressive drugs. TB is transmitted through the air and primarily attacks the lungs, then it can spread by the circulatory system to other parts of body. Once TB bacilli have entered the host by the respiratory route and infected macrophages in the lungs, they interfere with phagosomal maturation, antigen presentation, apoptosis and host immune system to establish persistent or latent infection.",
BMGC_PW0297,BMG_PW1045,"Trypanosoma cruzi is the causative agent of the Chagas disease, also known as the American trypanosomiasis, as it occurs primarily in poor areas of the Americas, mostly Central and South America. Infection interferes with a number of intracellular pathways and it appears to activate calcium signaling. [http://www.onelook.com OneLook, KEGG:map05142]","Trypanosoma cruzi is an intracellular protozoan parasite that causes Chagas disease, also called American trypanosomiasis. The parasite life cycle involves hematophagous reduviid bugs as vectors. Once parasites enter the host body, they invade diverse host cells including cardiomyocytes. Establishment of infection depends on various parasite molecules such as cruzipain, oligopeptidase B, and trans-sialidase that activate Ca2+ signaling. Internalized parasites escape from the parasitophorous vacuole using secreted pore-forming TcTOX molecule and replicate in the cytosol. Multiplied parasites eventually lyse infected host cells and are released in the circulation. During these events, the parasites manipulate host innate immunity and elicit cardiomyocyte hypertrophy. T lymphocyte responses are also disturbed.",
BMGC_PW0298,BMG_PW1046,"Several species of the protozoan parasite Plasmodium can infect humans and cause malaria. Severe malaria, which is primarily caused by Plasmodium falciparum, can lead to death and the fatalities are mostly children. Deregulated induction of cytokines appears to play a role in the infection. [KEGG:map05144]",Plasmodium protozoa are parasites that account for malaria infection. Sporozoite forms of the parasite are injected by mosquito bites under the skin and are carried to the liver where they develop into the merozoite form.             Sporozoite invasion of hepatocytes is mediated by parasite surface protein like CSP. Subsequent infection into red blood cells (RBCs) by merozoites causes malaria disease via aberrant cytokine production and sequestration of parasite-infected red blood cells (pRBCs) to host endothelium. Microvasculature sequestration in the brain brings about cerebral malaria that can results in death or persisting neurological impairment. PfEMP1 has been suggested as the key adhesive molecule of pRBCs.,
BMGC_PW0299,BMG_PW1047,"Toxoplasma gondii, whose hosts include various warm-blooded species including humans, is the causative agent of toxoplasmosis. The infection interferes with a number of host pathways; in its most severe manifestations it can be fatal. [http://www.onelook.com OneLook, KEGG:map05145]","Toxoplasma gondii is an obligate intracellular parasite that is prevalent worldwide. The tachyzoite form acquired by oral ingestion downmodulates proinflammatory signaling pathways via various mechanisms. During early infection, nuclear translocation of NFkB is temporally blocked and p38 MAPK phosphorylation is prevented, suppressing IL-12 production. Another pathway for IL-12 induction occurs through CCR5 dependent pathway, but parasitic induction of an eicosanoid LXA4 contributes to the downregulation of IL-12. Direct activation of STAT3 by the parasite enhance anti-inflammatory function of IL-10 and TGF beta. T. gondii can cause lifelong chronic infection by establishing an anti-apoptotic environment through induction of bcl-2 or IAPs and by redirecting LDL-mediated cholesterol transport to scavenge nutrients from the host.",
BMGC_PW0300,BMG_PW1049,The influenza A virus is the causative agent of seasonal epidemics and occasional pandemics of influenza which affects the respiratory system. [KEGG:map05164],"Influenza is a contagious respiratory disease caused by influenza virus infection. Influenza A virus is responsible for both annual seasonal epidemics and periodic worldwide pandemics. Novel strains that cause pandemics arise from avian influenza virus by genetic reassortment among influenza viruses and two surface glycoproteins HA and NA form the basis of serologically distinct virus types. The innate immune system recognizes invaded virus through multiple mechanisms. Viral non-structural NS1 protein is a multifunctional virulence factor that interfere IFN-mediated antiviral response. It inhibits IFN production by blocking activation of transcription factors such as NF-kappa B and IRF3. NS1 further inhibits the activation of IFN-induced antiviral genes. PB1-F2 protein is another virulence factor that induce apoptosis of infected cells, which results in life-threatening bronchiolitis.",
BMGC_PW0301,BMG_PW1050,"The hepatitis C virus is the causative agent of hepatitis C, a chronic liver disease in humans. The virus interferes with several signaling and regulatory pathways in the host cells. [http://www.onelook.com OneLook, KEGG:map05160]","Hepatitis C virus (HCV) is a major cause of chronic liver disease. The HCV employ several strategies to perturb host cell immunity. After invasion, HCV RNA genome functions directly as an mRNA in the cytoplasm of the host cell and forms membrane-associated replication complexes along with non-structural proteins. Viral RNA can trigger the RIG-I pathway and interferon production during this process. Translated HCV protein products regulate immune response to inhibit the action of interferon. HCV core and NS5A proteins appear to be the most important molecules with regulatory functions that modulate transcription, cellular proliferation, and apoptosis.",
BMGC_PW0302,BMG_PW1053,"The measles virus (MV) of the genus Morbillivirus is the causative agent of the condition that bears its name. The condition causes immunosuppression and several MV proteins are thought to interfere with the normal host immune responses. [http://www.onelook.com OneLook, KEGG:map05162]","Measles virus (MV) is highly contagious virus that leads infant death worldwide. Humans are the unique natural reservoir for this virus. MV infection is characterized by virus-induced immune suppression that can lead to increased susceptibility to secondary bacterial and viral infections. The P, V and C proteins act as virulence factors to suppress innate immune response in host by inhibiting signaling for both type I IFN induction and JAK/STAT-mediated interferon-stimulated gene (ISG) induction. Moreover,  H protein expressed on viral particles and binding to SLAM or CD46,  as well as N protein liberated from infected cells and interacting with Fc-gamma R, causes an inhibition of IL-12 synthesis in dendritic cells. IL-12 is a key cytokine inducing cellular immune responses to protect host from the harm caused by pathogenic infections.",
BMGC_PW0303,BMG_PW1055,"Primary bile acids, cholic and  chenodeoxycholic acids, are derived from cholesterol in the liver. Upon conjugation with glycine or taurine they can be secreted into the intestine. [http://www.onelook.com OneLook, KEGG:map00120]","Bile acids are steroid carboxylic acids derived from cholesterol in vertebrates. The primary bile acids, cholic acid and chenodeoxycholic acid, are synthesized in the liver and conjugated with taurine or glycine before secretion via bile into the intestine. The conversion from cholesterol to cholic and chenodeoxycholic acids involves four steps: 1) the initiation of synthesis by 7alpha-hydroxylation of sterol precursors, 2) further modifications to the ring structures, 3) side-chain oxidation and shortening (cleavage) by three carbons, and 4) conjugation of the bile acid with taurine or glycine.",
BMGC_PW0304,BMG_PW1056,"Secondary bile acids, deoxycholic and lithocholic acids, are synthesized from the primary ones by intestinal bacteria. like the primary bile acids, they need to be conjugated to glycine or taurine prior to secretion. [http://www.onelook.com OneLook, KEGG:map00121]",,
BMGC_PW0305,BMG_PW1058,"The metabolic reactions involving lipoic acid, a compound derived from octanoic acid that contains two sulfur centers. Lipoic acid is a co-factor for the pyruvate dehydrogenase complex responsible for the irreversible decarboxylation of pyruvate to acetyl-CoA. [GO:0009106, KEGG:00785, PMID:17052205]",,
BMGC_PW0306,BMG_PW1060,"Interstrand cross links (ICL) of DNA can be induced by both endogenous and exogenous ligands. ICL if not repaired will lead to cell death. The ICL repair pathway, also known as the Fanconi anemia pathway, is the cellular response to this type of DNA damage. [GO:0036297, KEGG:03460, PMID:19061902, PMID:20713514, PMID:21605559, Reactome:R-HSA-6783310]","The Fanconi anemia pathway is required for the efficient repair of damaged DNA, especially interstrand cross-links (ICLs). DNA ICL is directly recognized by FANCM and associated proteins, that recruit the FA core complex. The FA core complex monoubiquitinates FANCD2 and FANCI. The monoubiquitinated FANCD2/FANCI becomes an active form and interacts with a series of DNA repair proteins and facilitates downstream repair pathways. Fanconi anemia is caused by mutations in one of at least 13 FA genes and is characterized by congenital growth abnormalities, bone marrow failure and cancer predisposition.","Fanconi anemia (FA) is a genetic disease of genome instability characterized by congenital skeletal defects, aplastic anemia, susceptibility to leukemias, and cellular sensitivity to DNA damaging agents. Patients with FA have been categorized into at least 15 complementation groups (FA-A, -B, -C, -D1, -D2, -E, -F, -G, -I, -J, -L, -M, -N, -O and -P). These complementation groups correspond to the genes FANCA, FANCB, FANCC, FANCD1/BRCA2, FANCD2, FANCE, FANCF, FANCG, FANCJ/BRIP1, FANCL, FANCM, FANCN/PALB2, FANCO/RAD51C and FANCP/SLX4. Eight of these proteins, FANCA, FANCB, FANCC, FANCE, FANCF, FANCG, FANCL, and FANCM, together with FAAP24, FAAP100, FAAP20, APITD1 and STRA13, form a nuclear complex termed the FA core complex. The FA core complex is an E3 ubiquitin ligase that recognizes and is activated by DNA damage in the form of interstrand crosslinks (ICLs), triggering monoubiquitination of FANCD2 and FANCI, which initiates repair of ICL-DNA. FANCD2 and FANCI form a complex and are mutually dependent on one another for their respective monoubiquitination. After DNA damage and during S phase, FANCD2 localizes to discrete nuclear foci that colocalize with proteins involved in homologous recombination repair, such as BRCA1 and RAD51. The FA pathway is regulated by ubiquitination and phosphorylation of FANCD2 and FANCI. ATR-dependent phosphorylation of FANCI and FANCD2 promotes monoubiquitination of FANCD2, stimulating the FA pathway (Cohn and D'Andrea 2008, Wang 2007). The complex of USP1 and WDR48 (UAF1) is responsible for deubiquitination of FANCD2 and negatively regulates the FA pathway (Cohn et al. 2007). Monoubiquitinated FANCD2 recruits DNA nucleases, including SLX4 (FANCP) and FAN1, which unhook the ICL from one of the two covalently linked DNA strands. The DNA polymerase nu (POLN) performs translesion DNA synthesis using the DNA strand with unhooked ICL as a template, thereby bypassing the unhooked ICL. The unhooked ICL is subsequently removed from the DNA via nucleotide excision repair (NER). Incision of the stalled replication fork during the unhooking step generates a double strand break (DSB). The DSB is repaired via homologous recombination repair (HRR) and involves the FA genes BRCA2 (FANCD1), PALB2 (FANCN) and BRIP1 (FANCJ) (reviewed by Deans and West 2011, Kottemann and Smogorzewska 2013). Homozygous mutations in BRCA2, PALB2 or BRIP1 result in Fanconi anemia, while heterozygous mutations in these genes predispose carriers to primarily breast and ovarian cancer. Well established functions of BRCA2, PALB2 and BRIP1 in DNA repair are BRCA1 dependent, but it is not yet clear whether there are additional roles for these proteins in the Fanconi anemia pathway that do not rely on BRCA1 (Evans and Longo 2014, Jiang and Greenberg 2015). Heterozygous BRCA1 mutations predispose carriers to breast and ovarian cancer with high penetrance. Complete loss of BRCA1 function is embryonic lethal. It has only recently been reported that a partial germline loss of BRCA1 function via mutations that diminish protein binding ability of the BRCT domain of BRCA1 result in a FA-like syndrome. BRCA1 has therefore been designated as the FANCS gene (Jiang and Greenberg 2015). The FA pathway is involved in repairing DNA ICLs that arise by exposure to endogenous mutagens produced as by-products of normal cellular metabolism, such as aldehyde containing compounds. Disruption of the aldehyde dehydrogenase gene ALDH2 in FANCD2 deficient mice leads to severe developmental defects, early lethality and predisposition to leukemia. In addition to this, the double knockout mice are exceptionally sensitive to ethanol consumption, as ethanol metabolism results in accumulated levels of aldehydes (Langevin et al. 2011)."
BMGC_PW0307,BMG_PW1061,"The pathway of ribosome biogenesis starts with the transcription of rRNA precursors, and involves the co-transciptional events of pre-rRNA processing and the assembly of pre-ribosomal particles. The maturation of pre-40S and pre-60S particles follows independent routes. Once in the cytoplasm, additional steps yield the mature, translation-competent ribosome. Alterations in the pathway result in specific phenotypes collectively known as ribosomopathies. [GO:0042254, KEGG:03008, PMID:20194897, PMID:20875629]","Ribosomes are the cellular factories responsible for making proteins. In eukaryotes, ribosome biogenesis involves the production and correct assembly of four rRNAs and about 80 ribosomal proteins. It requires hundreds of factors not present in the mature particle. In the absence of these proteins, ribosome biogenesis is stalled and cell growth is terminated even under optimal growth conditions. The primary pre-rRNA transcript is assembled into the 90S pre-ribosome, which contains both 40S and 60S assembly factors. Within this complex, the pre-rRNA is cleaved. pre-60S ribosomes are subjected to several sequential processing steps in the nucleoplasm involving numerous assembly intermediates before it is exported to the cytoplasm and matured into the 60S ribosomal subunit. The pre-40S ribosome is matured to the small ribosomal subunit in the cytoplasm by cleavage.",
BMGC_PW0308,BMG_PW1131,"The C16 palmitate product of the fatty acid biosynthetic pathway can be esterifed to triacylglycerol or converted to longer chain saturated and unsaturated fatty acid molecules by elongases and desaturases, depending on the needs of the cell. The elongation pathway takes place in the endoplasmic reticulum or in the mitochondrion. Longer chain fatty acids are present in certain specialized tissues; for instance, myelin contains large amounts of C22 and C24 molecules. [GO:0030497, KEGG:00062, PMID:22984005, SMP:00054]",,
BMGC_PW0309,BMG_PW1132,"The C16 palmitate product of the fatty acid biosynthetic pathway can be esterifed to triacylglycerol or converted to longer chain saturated and unsaturated fatty acid molecules by elongases and desaturases, depending on the needs of the cell. Unsaturated fatty acids are essential membrane components. [GO:0006636, KEGG:map01040]",,
BMGC_PW0310,BMG_PW1133,"Those metabolic reactions involving ether lipids, lipid molecules in which one or several of the carbons on glycerol has an ether linkage to an alkyl chain. Ether lipids are constituents of cell membrane; some metabolites could act as signaling second messengers or carry out antioxidant functions. [GO:0046485, https://en.wikipedia.org/wiki/Ether_lipid wikipedia, KEGG:00565]",,
BMGC_PW0311,BMG_PW1137,"The clathrin-mediated endocytosis pathway involves clathrin-coated vesicles used for the engulfment of material. [GO:0072583, http://en.wikipedia.org/wiki/Endocytosis Wikipedia, PMID:16985500, Reactome:R-HSA-8856828]",,"Clathrin-mediated endocytosis (CME) is one of a number of process that control the uptake of material from the plasma membrane, and leads to the formation of clathrin-coated vesicles (Pearse et al, 1975; reviewed in Robinson, 2015; McMahon and Boucrot, 2011; Kirchhausen et al, 2014). CME contributes to signal transduction by regulating the cell surface expression and signaling of receptor tyrosine kinases (RTKs) and G-protein coupled receptors (GPCRs). Most RTKs exhibit a robust increase in internalization rate after binding specific ligands; however, some RTKs may also exhibit significant ligand-independent internalization (reviewed in Goh and Sorkin, 2013). CME controls RTK and GPCR signaling by organizing signaling both within the plasma membrane and on endosomes (reviewed in Eichel et al, 2016; Garay et al, 2015; Vieira et al, 1996; Sorkin and von Zastrow, 2014; Di Fiori and von Zastrow, 2014; Barbieri et al, 2016). CME also contributes to the uptake of material such as metabolites, hormones and other proteins from the extracellular space, and regulates membrane composition by recycling membrane components and/or targeting them for degradation. Clathrin-mediated endocytosis involves initiation of clathrin-coated pit (CCP) formation, cargo selection, coat assembly and stabilization, membrane scission and vesicle uncoating. Although for simplicity in this pathway, the steps leading to a mature CCP are represented in a linear and temporally distinct fashion, the formation of a clathrin-coated vesicle is a highly heterogeneous process and clear temporal boundaries between these processes may not exist (see for instance Taylor et al, 2011; Antonescu et al, 2011; reviewed in Kirchhausen et al, 2014). Cargo selection in particular is a critical aspect of the formation of a mature and stable CCP, and many of the proteins involved in the initiation and maturation of a CCP contribute to cargo selection and are themselves stabilized upon incorporation of cargo into the nascent vesicle (reviewed in Kirchhausen et al, 2014; McMahon and Boucrot, 2011). Although the clathrin triskelion was identified early as a major component of the coated vesicles, clathrin does not bind directly to membranes or to the endocytosed cargo. Vesicle formation instead relies on many proteins and adaptors that can bind the plasma membrane and interact with cargo molecules. Cargo selection depends on the recognition of endocytic signals in cytoplasmic tails of the cargo proteins by adaptors that interact with components of the vesicle's inner coat. The classic adaptor for clathrin-coated vesicles is the tetrameric AP-2 complex, which along with clathrin was identified early as a major component of the coat. Some cargo indeed bind directly to AP-2, but subsequent work has revealed a large family of proteins collectively known as CLASPs (clathrin- associated sorting proteins) that mediate the recruitment of diverse cargo into the emerging clathrin-coated vesicles (reviewed in Traub and Bonifacino, 2013). Many of these CLASP proteins themselves interact with AP-2 and clathrin, coordinating cargo recruitment with coat formation (Schmid et al, 2006; Edeling et al, 2006; reviewed in Traub and Bonifacino, 2013; Kirchhausen et al, 2014). Initiation of CCP formation is also influenced by lipid composition, regulated by clathrin-associated phosphatases and kinases (reviewed in Picas et al, 2016). The plasma membrane is enriched in PI(4,5)P2. Many of the proteins involved in initiating clathrin-coated pit formation bind to PI(4,5)P2 and induce membrane curvature through their BAR domains (reviewed in McMahon and Boucrot, 2011; Daumke et al, 2014). Epsin also contributes to early membrane curvature through its Epsin N-terminal homology (ENTH) domain, which promotes membrane curvature by inserting into the lipid bilayer (Ford et al, 2002). Following initiation, some CCPs progress to formation of vesicles, while others undergo disassembly at the cell surface without producing vesicles (Ehrlich et al, 2004; Loerke et al, 2009; Loerke et al, 2011; Aguet et al, 2013; Taylor et al, 2011). The assembly and stabilization of nascent CCPs is regulated by several proteins and lipids (Mettlen et al, 2009; Antonescu et al, 2011). Maturation of the emerging clathrin-coated vesicle is accompanied by further changes in the lipid composition of the membrane and increased membrane curvature, promoted by the recruitment of N-BAR domain containing proteins (reviewed in Daumke et al, 2014; Ferguson and De Camilli, 2012; Picas et al, 2016). Some N-BAR domain containing proteins also contribute to the recruitment of the large GTPase dynamin, which is responsible for scission of the mature vesicle from the plasma membrane (Koh et al, 2007; Lundmark and Carlsson, 2003; Soulet et al, 2005; David et al, 1996; Owen et al, 1998; Shupliakov et al, 1997; Taylor et al, 2011; Ferguson et al, 2009; Aguet et al, 2013; Posor et al, 2013; Chappie et al, 2010; Shnyrova et al, 2013; reviewed in Mettlen et al, 2009; Daumke et al, 2014). After vesicle scission, the clathrin coat is dissociated from the new vesicle by the ATPase HSPA8 (also known as HSC70) and its DNAJ cofactor auxilin, priming the vesicle for fusion with a subsequent endocytic compartment and releasing clathrin for reuse (reviewed in McMahon and Boucrot, 2011; Sousa and Laufer, 2015)."
BMGC_PW0312,BMG_PW1140,"The phagocytosis pathway is used for the removal of unwanted material such as dying cells and also of foreign material. As such it is also part of the immune response. Various receptors on the surface of a phagocytic cell will recognize/bind material and induce signaling cascades. [GO:0006909, KEGG:04145, PMID:16985500, PMID:9039775]","Phagocytosis is the process of taking in relatively large particles by a cell, and is a central mechanism in the tissue remodeling, inflammation, and defense against infectious agents. A phagosome is formed when the specific receptors on the phagocyte surface recognize ligands on the particle surface. After formation, nascent phagosomes progressively acquire digestive characteristics. This maturation of phagosomes involves regulated interaction with the other membrane organelles, including recycling endosomes, late endosomes and lysosomes. The fusion of phagosomes and lysosomes releases toxic products that kill most bacteria and degrade them into fragments. However, some bacteria have strategies to escape the bactericidal mechanisms associated with phagocytosis and survive within host phagocytes.",
BMGC_PW0313,BMG_PW1147,"Those metabolic reactions involved in the synthesis of steroids. Notable examples include cholesterol and steroid hormones. [GO:0006694, http://en.wikipedia.org/wiki/Steroid wikipedia, KEGG:00100]",,
BMGC_PW0314,BMG_PW1148,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of caffeine, a xanthine alkaloid found in the seeds, leaves, and fruit of certain plants that humans use as a stimulant. [http://en.wikipedia.org/wiki/Caffeine wikipedia, KEGG:00232]",,
BMGC_PW0315,BMG_PW1149,"Those metabolic reactions involved in the degradation of glycosaminoglycans. [GO:0006027, KEGG:00531]",,
BMGC_PW0316,BMG_PW1151,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glycerolipids, which are composed of mono-, di-, and tri-substituted glycerols. Triacylglycerol, or triglyceride, is the best known example. [GO:0046486, http://www.onelook.com OneLook, KEGG:00561, SMP:00039]",,
BMGC_PW0317,BMG_PW1153,"Those enzymatic reactions involved in the synthesis, utilization or degradation of alpha-linolenic acid - an unsaturated omega-3 fatty acid. Alpha-linolenic acid is an essential fatty acid that humans and other animals cannot synthesize and must obtain from diet. [GO:0036109, http://en.wikipedia.org/wiki/Alpha-Linolenic_acid wikipedia, KEGG:00592, Reactome:R-HSA-2046106, SMP:00018]",,"Alpha-linolenic acid (ALA, 18:3(n-3)) is an omega-3 fatty acid, supplied through diet as it cannot be synthesized by humans. ALA has an important role in human health. It is converted to long chain more unsaturated n-3 fatty acids by a series of alternating desaturation and elongation reactions. Omega-3 products of ALA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduce inflammation and may help lower risk of chronic diseases, such as heart disease and arthritis. All the desaturation and elongation steps occur in the endoplasmic reticulum (ER) except for the final step which requires translocation to peroxisomes for partial beta-oxidation. The alpha-linolenic acid pathway involves the following steps: 18:3(n-3)--> 18:4(n-3)-->20:4(n-3)-->20:5(n-3)-->22:5(n-3)-->24:5(n-3)-->24:6(n-3)-->22:6(n-3). Two desaturation enzymes are involved in this process: delta-6 desaturase that converts 18:3(n-3) to 18:4(n-3) and 24:5(n-3) to 24:6(n-3) respectively, delta-5 desaturase 20:4(n-3) to 20:5(n-3). (Sprecher 2002)."
BMGC_PW0318,BMG_PW1154,"Aminoacyl-tRNA, or transfer RNA (tRNA) carries amino acids to ribosomes and is part of the translation pathway. tRNAs are specific for the amino acids with which they are associated. Their synthesis involves adenylation of the amino acid followed by its transfer; both steps require ATP. [GO:0043039, http://en.wikipedia.org/wiki/Aminoacyl-tRNA wikipedia, KEGG:00970, Reaactome:R-HSA-379724]",,
BMGC_PW0319,BMG_PW1155,"The pathway whereby various RNA molecules synthesized in the nucleus are exported to the cytoplasm to be further processed such as protein-coding mRNA or to fulfill particular functions. [GO:0050658, KEGG:03013, PMID:15519698, PMID:21776079]","The exchange of molecules between the nucleus and cytoplasm is mediated through nuclear pore complexes (NPCs) embedded in the nuclear envelope. The NPC is composed of highly conserved, distinct structural modules: the inner pore ring, the cytoplasmic and nuclear rings as well as the cytoplasmic filaments and the nuclear basket. Nuclear transport receptors (e.g. importins and exportins) mediate translocation of cargos through the NPC. Cargo proteins harbouring a nuclear export signal (NES) bind to exportins and Ran-GTP to form an export complex in the nucleoplasm. Nuclear export of bulk mRNA is provided by the non-karyopherin transport proteins TAP-p15 in a Ran-GTP-independent manner. Several EJC factors are known to function in mRNA export.",
BMGC_PW0320,BMG_PW1156,"The turnover of RNA molecules produced by the three eukaryotic polymerases and those resulting from their processing and/or assembly. It includes the degradation of defective molecules, of excess molecules, or of defective components by the RNA surveillance or decay pathway. [GO:0006401, KEGG:03018, PMID:19239894]","The correct processing, quality control and turnover of cellular RNA molecules are critical to many aspects in the expression of genetic information. In eukaryotes, two major pathways of mRNA decay exist and both pathways are initiated by poly(A) shortening of the mRNA. In the 5' to 3' pathway, this is followed by decapping which then permits the 5' to 3' exonucleolytic degradation of transcripts. In the 3' to 5' pathway, the exosome, a large multisubunit complex, plays a key role. The exosome exists in archaeal cells, too. In bacteria, endoribonuclease E, a key enzyme involved in RNA decay and processing, organizes a protein complex called degradosome. RNase E or R interacts with the phosphate-dependent exoribonuclease polynucleotide phosphorylase, DEAD-box helicases, and additional factors in the RNA-degrading complex.",
BMGC_PW0321,BMG_PW1159,"The signaling pathway initiated by the endogenous cannabinoids that activate the G-protein-coupled (GPCR) cannabinoid receptors and utilize a retrograde route from the postsynaptic to the presynaptic neuron. [GO:0071926, KEGG:04723, PMID:21531987]","Endogenous cannabinoids (endocannabinoids) serve as retrograde messengers at synapses in various regions of the brain. The family of endocannabinoids includes at least five derivatives of arachidonic acid; the two best characterized are arachydonoyl ethanolamide (anandamide, AEA) and 2-arachydonoil glycerol (2AG). They are released from postsynaptic neurons upon postsynaptic depolarization and/or receptor activation. The released endocannabinoids then activate the CB1 receptors (CB1R) at presynaptic terminals and suppress the release of inhibitory transmitter GABA (depolarization-induced suppression of inhibition, DSI) or excitatory transmitter glutamate (depolarization-induced suppression of excitation, DSE) by inhibiting Ca2+ channels. Besides the well-known expression of the CB1R in the plasma membrane, this receptor is also present in mitochondrial membranes, where it reduces the mitochondrial respiration and contributes to DSI. Whereas DSI and DSE result in short-term synaptic plasticity, endocannabinoids also mediate long-term synaptic changes (eCB-LTD). Persistent activation of CB1 receptors over a period of minutes triggers eCB-LTD by a RIM1alpha-dependent mechanism.",
BMGC_PW0322,BMG_PW1222,"The Stem Cell Factor (SCF) signaling pathway plays important roles in cell migration, proliferation and survival. SCF activates the KIT receptor tyrosine kinase which then prompts several intracellular signaling pathways. Deregulation of the pathway has been associated with several conditions including cancer. [GO:0038109, PMID:23073628, Reactome:R-HSA-1433557]",,"Stem cell factor (SCF) is a growth factor with membrane bound and soluble forms. It is expressed by fibroblasts and endothelial cells throughout the body, promoting proliferation, migration, survival and differentiation of hematopoetic progenitors, melanocytes and germ cells.(Linnekin 1999, Ronnstrand 2004, Lennartsson and Ronnstrand 2006). The receptor for SCF is KIT, a tyrosine kinase receptor (RTK) closely related to the receptors for platelet derived growth factor receptor, colony stimulating factor 1 (Linnekin 1999) and Flt3 (Rosnet et al. 1991). Four isoforms of c-Kit have been identified in humans. Alternative splicing results in isoforms of KIT differing in the presence or absence of four residues (GNNK) in the extracellular region. This occurs due to the use of an alternate 5' splice donor site. These GNNK+ and GNNK- variants are co-expressed in most tissues; the GNNK- form predominates and was more strongly tyrosine-phosphorylated and more rapidly internalized (Ronnstrand 2004). There are also splice variants that arise from alternative usage of splice acceptor site resulting in the presence or absence of a serine residue (Crosier et al., 1993). Finally, there is an alternative shorter transcript of KIT expressed in postmeiotic germ cells in the testis which encodes a truncated KIT consisting only of the second part of the kinase domain and thus lackig the extracellular and transmembrane domains as well as the first part of the kinase domain (Rossi et al. 1991). Binding of SCF homodimers to KIT results in KIT homodimerization followed by activation of its intrinsic tyrosine kinase activity. KIT stimulation activates a wide array of signalling pathways including MAPK, PI3K and JAK/STAT (Reber et al. 2006, Ronnstrand 2004). Defects of KIT in humans are associated with different genetic diseases and also in several types of cancers like mast cell leukaemia, germ cell tumours, certain subtypes of malignant melanoma and gastrointestinal tumours."
BMGC_PW0323,BMG_PW1230,"Those metabolic reactions involved in the synthesis of catecholamines. Epinephrine, norepinephrine and dopamine are among the most abundant and are produced primarily from the adrenal medulla and the postganglionic fibers of the sympathetic nervous system. [GO:0042423, PMID:19342614, Reactome:R-HSA-209905, SMP:00012]",,"The catecholamine neurotransmitters dopamine, noradrenaline and adrenaline are found in nervous tissue of animals. They are synthesized in catecholaminergic neurons by four enzymes from tyrosine to adrenaline: tyrosine hydroxylase (TH); aromatic L-amino acid decarboxylase (AADC); dopamine beta-hydroxylase (DBH); and phenylethanolamine N-methyltransferase (PNMT)."
BMGC_PW0324,BMG_PW1247,"The prolactin signaling pathway is important for normal reproduction. Prolactin is a peptide hormone whose signaling activates several intracellular cascades. [GO:0038161, PMID:21664429, PMID:22684822, Reactome:R-HSA-1170546]","Prolactin (PRL) is a polypeptide hormone known to be involved in a wide range of biological functions including osmoregulation, lactation, reproduction, growth and development, endocrinology and metabolism, brain and behavior, and immunomodulation. PRL mediates its action through PRLR, a transmembrane protein of the hematopoietin cytokine receptor superfamily. At the protein level, the long PRLR isoform (long-R) and several short PRLR isoforms (short-R) have been detected. Acting through the long-R, PRL activates many signaling cascades including Jak2/Stat, the major cascade, Src kinase, phosphatidylinositol-3-kinase (PI3K)/AKT, and mitogen-activated protein kinase (MAPK) pathways. PRL cannot activate Jak2/Stat5 through the short-R, but can activate pathways including MAPK and PI3K pathways.","Prolactin (PRL) is a hormone secreted mainly by the anterior pituitary gland. It was originally identified by its ability to stimulate the development of the mammary gland and lactation, but is now known to have numerous and varied functions (Bole-Feysot et al. 1998). Despite this, few pathologies have been associated with abnormalities in prolactin receptor (PRLR) signaling, though roles in various forms of cancer and certain autoimmune disorders have been suggested (Goffin et al. 2002). A vast body of literature suggests effects of PRL in immune cells (Matera 1996) but PRLR KO mice have unaltered immune system development and function (Bouchard et al. 1999). In addition to the pituitary, numerous other tissues produce PRL, including the decidua and myometrium, certain cells of the immune system, brain, skin and exocrine glands such as the mammary, sweat and lacrimal glands (Ben-Jonathan et al. 1996). Pituitary PRL secretion is negatively regulated by inhibitory factors originating from the hypothalamus, the most important of which is dopamine, acting through the D2 subclass of dopamine receptors present in lactotrophs (Freeman et al. 2000). PRL-binding sites or receptors have been identified in numerous cells and tissues of adult mammals. Various forms of PRLR, generated by alternative splicing, have been reported in several species including humans (Kelly et al. 1991, Clevenger et al. 2003). PRLR is a member of the cytokine receptor superfamily. Like many other members of this family, the first step in receptor activation was generally believed to be ligand-induced dimerization whereby one molecule of PRL bound to two molecules of receptor (Elkins et al. 2000). Recent reports suggest that PRLR pre-assembles at the plasma membrane in the absence of ligand (Gadd & Clevenger 2006, Tallet et al. 2011), suggesting that ligand-induced activation involves conformational changes in preformed PRLR dimers (Broutin et al. 2010). PRLR has no intrinsic kinase activity but associates (Lebrun et al. 1994, 1995) with Janus kinase 2 (JAK2) which is activated following receptor activation (Campbell et al. 1994, Rui et al. 1994, Carter-Su et al. 2000, Barua et al. 2009). JAK2-dependent activation of JAK1 has also been reported (Neilson et al. 2007). It is generally accepted that activation of JAK2 occurs by transphosphorylation upon ligand-induced receptor activation, based on JAK activation by chimeric receptors in which various extracellular domains of cytokine or tyrosine kinase receptors were fused to the IL-2 receptor beta chain (see Ihle et al. 1994). This activation step involves the tyrosine phosphorylation of JAK2, which in turn phosphorylates PRLR on specific intracellular tyrosine residues leading to STAT5 recruitment and signaling, considered to be the most important signaling cascade for PRLR. STAT1 and STAT3 activation have also been reported (DaSilva et al. 1996) as have many other signaling pathways; signaling through MAP kinases (Shc/SOS/Grb2/Ras/Raf/MAPK) has been reported as a consequence of PRL stimuilation in many different cellular systems (see Bole-Feysot et al. 1998) though it is not clear how this signal is propagated. Other cascades non exhaustively include Src kinases, Focal adhesion kinase, phospholipase C gamma, PI3 kinase/Akt and Nek3 (Clevenger et al. 2003, Miller et al. 2007). The protein tyrosine phosphatase SHP2 is recruited to the C terminal tyrosine of PRLR and may have a regulatory role (Ali & Ali 2000). PRLR phosphotyrosines can recruit insulin receptor substrates (IRS) and other adaptor proteins to the receptor complex (Bole-Feysot et al. 1998). Female homozygous PRLR knockout mice are completely infertile and show a lack of mammary development (Ormandy et al. 1997). Hemizogotes are unable to lactate following their first pregnancy and depending on the genetic background, this phenotype can persist through subsequent pregnancies (Kelly et al. 2001)."
BMGC_PW0325,BMG_PW1260,"Those metabolic reactions involved in the degradation of glycine. Several routes are available, of which the glycine cleavage system is the predominant one. It occurs in the mitochondria and produces 5,10-methylene tetrahydrofolate and as such, is an important component of the folate cycle pathway. [GO:0006546, http://en.wikipedia.org/wiki/Glycine wikipedia, PMID:18941301, Reactome:R-HSA-6783984]",,"The simplest amino acid, glycine, is catabolised by several different pathways. The major pathway is via the glycine cleavage system, comprising dimeric P protein (GLDC), T protein (AMT, GCST), dimeric L protein (DLD) and H protein (GCSH) (Kikuchi et al. 2008)."
BMGC_PW0326,BMG_PW1262,"Those metabolic reactions involved in the degradation of histidine. Histidine degradation provides a source of nitrogen and is carried out in microorganisms. [GO:0006548, PMID:24165547, PMID:24728193, Reactome:R-HSA-70921]",,"The major pathway of histidine catabolism, annotated here, proceeds in four steps to yield glutamate and, in the process, convert one molecule of tetrahydrofolate to 5-formiminotetrahydrofolate (Morris et al. 1972). Histidine can also be decarboxylated to form histamine. Histidine can also be used to form carnosine (beta-alanyl-L-histidine), an abundant dipeptide in skeletal muscle and brain of most vertebrates."
BMGC_PW0327,BMG_PW1269,"RNA polymerase II and a set of general and specific transcription factors assemble as a large pre-initiation complex which undergoes a series of transformations before transcription proceeds. Promoter recognition and subsequent initiation of transcription are dependent upon the presence of these transcription factors. Activators and repressors impact upon transcription at these early stages. [GO:0006367, PMID:23000482, Reactome:R-HSA-75953]",,"Formation of the open complex exposes the template strand to the catalytic center of the RNA polymerase II enzyme. This facilitates formation of the first phosphodiester bond, which marks transcription initiation. As a result of this, the TFIIB basal transcription factor dissociates from the initiation complex. The open transcription initiation complex is unstable and can revert to the closed state. Initiation at this stage requires continued (d)ATP-hydrolysis by TFIIH. Dinucleotide transcripts are not stably associated with the transcription complex. Upon dissociation they form abortive products. The transcription complex is also sensitive to inhibition by small oligo-nucleotides. Dinucleotides complementary to position -1 and +1 in the template can also direct first phosphodiester bond formation. This reaction is independent on the basal transcription factors TFIIE and TFIIH and does not involve open complex formation. This reaction is sensitive to inhibition by single-stranded oligonucleotides."
BMGC_PW0328,BMG_PW1270,"The pathway of DNA transcription carried out by the eukaryotic polymerases. [GO:0006351, http://en.wikipedia.org/wiki/Transcription_%28genetics%29 wikipedia, Reactome:R-HSA-212436]",,"OVERVIEW OF TRANSCRIPTION REGULATION: Detailed studies of gene transcription regulation in a wide variety of eukaryotic systems has revealed the general principles and mechanisms by which cell- or tissue-specific regulation of differential gene transcription is mediated (reviewed in Naar, 2001. Kadonaga, 2004, Maston, 2006, Barolo, 2002; Roeder, 2005, Rosenfeld, 2006). Of the three major classes of DNA polymerase involved in eukaryotic gene transcription, Polymerase II generally regulates protein-encoding genes. Figure 1 shows a diagram of the various components involved in cell-specific regulation of Pol-II gene transcription. Core Promoter: Pol II-regulated genes typically have a Core Promoter where Pol II and a variety of general factors bind to specific DNA motifs: i: the TATA box (TATA DNA sequence), which is bound by the ""TATA-binding protein"" (TBP). ii: the Initiator motif (INR), where Pol II and certain other core factors bind, is present in many Pol II-regulated genes. iii: the Downstream Promoter Element (DPE), which is present in a subset of Pol II genes, and where additional core factors bind. The core promoter binding factors are generally ubiquitously expressed, although there are exceptions to this. Proximal Promoter: immediately upstream (5') of the core promoter, Pol II target genes often have a Proximal Promoter region that spans up to 500 base pairs (b.p.), or even to 1000 b.p.. This region contains a number of functional DNA binding sites for a specific set of transcription activator (TA) and transcription repressor (TR) proteins. These TA and TR factors are generally cell- or tissue-specific in expression, rather than ubiquitous, so that the presence of their cognate binding sites in the proximal promoter region programs cell- or tissue-specific expression of the target gene, perhaps in conjunction with TA and TR complexes bound in distal enhancer regions. Distal Enhancer(s): many or most Pol II regulated genes in higher eukaryotes have one or more distal Enhancer regions which are essential for proper regulation of the gene, often in a cell or tissue-specific pattern. Like the proximal promoter region, each of the distal enhancer regions typically contain a cluster of binding sites for specific TA and/or TR DNA-binding factors, rather than just a single site. Enhancers generally have three defining characteristics: i: They can be located very long distances from the promoter of the target gene they regulate, sometimes as far as 100 Kb, or more. ii: They can be either upstream (5') or downstream (3') of the target gene, including within introns of that gene. iii: They can function in either orientation in the DNA. Combinatorial mechanisms of transcription regulation: The specific combination of TA and TR binding sites within the proximal promoter and/or distal enhancer(s) provides a ""combinatorial transcription code"" that mediates cell- or tissue-specific expression of the associated target gene. Each promoter or enhancer region mediates expression in a specific subset of the overall expression pattern. In at least some cases, each enhancer region functions completely independently of the others, so that the overall expression pattern is a linear combination of the expression patterns of each of the enhancer modules. Co-Activator and Co-Repressor Complexes: DNA-bound TA and TR proteins typically recruit the assembly of specific Co-Activator (Co-A) and Co-Repressor (Co-R) Complexes, respectively, which are essential for regulating target gene transcription. Both Co-A's and Co-R's are multi-protein complexes that contain several specific protein components. Co-Activator complexes generally contain at lease one component protein that has Histone Acetyl Transferase (HAT) enzymatic activity. This functions to acetylate Histones and/or other chromatin-associated factors, which typically increases that transcription activation of the target gene. By contrast, Co-Repressor complexes generally contain at lease one component protein that has Histone De-Acetylase (HDAC) enzymatic activity. This functions to de-acetylate Histones and/or other chromatin-associated factors. This typically increases the transcription repression of the target gene. Adaptor (Mediator) complexes: In addition to the co-activator complexes that assemble on particular cell-specific TA factors, - there are at least two additional transcriptional co-activator complexes common to most cells. One of these is the Mediator complex, which functions as an ""adaptor"" complex that bridges between the tissue-specific co-activator complexes assembled in the proximal promoter (or distal enhancers). The human Mediator complex has been shown to contain at least 19 protein distinct components. Different combinations of these co-activator proteins are also found to be components of specific transcription Co-Activator complexes, such as the DRIP, TRAP and ARC complexes described below. TBP/TAF complex: Another large Co-A complex is the ""TBP-associated factors"" (TAFs) that assemble on TBP (TATA-Binding Protein), which is bound to the TATA box present in many promoters. There are at least 23 human TAF proteins that have been identified. Many of these are ubiquitously expressed, but TAFs can also be expressed in a cell or tissue-specific pattern. Specific Coactivator Complexes for DNA-binding Transcription Factors. A number of specific co-activator complexes for DNA-binding transcription factors have been identified, including DRIP, TRAP, and ARC (reviewed in Bourbon, 2004, Blazek, 2005, Conaway, 2005, and Malik, 2005). The DRIP co-activator complex was originally identified and named as a specific complex associated with the Vitamin D Receptor member of the nuclear receptor family of transcription factors (Rachez, 1998). Similarly, the TRAP co-activator complex was originally identified as a complex that associates with the thyroid receptor (Yuan, 1998). It was later determined that all of the components of the DRIP complex are also present in the TRAP complex, and the ARC complex (discussed further below). For example, the DRIP205 and TRAP220 proteins were show to be identical, as were specific pairs of the other components of these complexes (Rachez, 1999). In addition, these various transcription co-activator proteins identified in mammalian cells were found to be the orthologues or homologues of the Mediator (""adaptor"") complex proteins (reviewed in Bourbon, 2004). The Mediator proteins were originally identified in yeast by Kornberg and colleagues, as complexes associated with DNA polymerase (Kelleher, 1990). In higher organisms, Adapter complexes bridge between the basal transcription factors (including Pol II) and tissue-specific transcription factors (TFs) bound to sites within upstream Proximal Promoter regions or distal Enhancer regions (Figure 1). However, many of the Mediator homologues can also be found in complexes associated with specific transcription factors in higher organisms. A unified nomenclature system for these adapter / co-activator proteins now labels them Mediator 1 through Mediator 31 (Bourbon, 2004). For example, the DRIP205 / TRAP220 proteins are now identified as Mediator 1 (Rachez, 1999), based on homology with yeast Mediator 1. Example Pathway: Specific Regulation of Target Genes During Notch Signaling: One well-studied example of cell-specific regulation of gene transcription is selective regulation of target genes during Notch signaling. Notch signaling was first identified in Drosophila, where it has been studied in detail at the genetic, molecular, biochemical and cellular levels (reviewed in Justice, 2002; Bray, 2006; Schweisguth, 2004; Louvri, 2006). In Drosophila, Notch signaling to the nucleus is thought always to be mediated by one specific DNA binding transcription factor, Suppressor of Hairless. In mammals, the homologous genes are called CBF1 (or RBPJkappa), while in worms they are called Lag-1, so that the acronym ""CSL"" has been given to this conserved transcription factor family. There are at least two human CSL homologues, which are now named RBPJ and RBPJL. In Drosophila, Su(H) is known to be bifunctional, in that it represses target gene transcription in the absence of Notch signaling, but activates target genes during Notch signaling. At least some of the mammalian CSL homologues are believed also to be bifunctional, and to mediate target gene repression in the absence of Notch signaling, and activation in the presence of Notch signaling. Notch Co-Activator and Co-Repressor complexes: This repression is mediated by at least one specific co-repressor complexes (Co-R) bound to CSL in the absence of Notch signaling. In Drosophila, this co-repressor complex consists of at least three distinct co-repressor proteins: Hairless, Groucho, and dCtBP (Drosophila C-terminal Binding Protein). Hairless has been show to bind directly to Su(H), and Groucho and dCtBP have been shown to bind directly to Hairless (Barolo, 2002). All three of the co-repressor proteins have been shown to be necessary for proper gene regulation during Notch signaling in vivo (Nagel, 2005). In mammals, the same general pathway and mechanisms are observed, where CSL proteins are bifunctional DNA binding transcription factors (TFs), that bind to Co-Repressor complexes to mediate repression in the absence of Notch signaling, and bind to Co-Activator complexes to mediate activation in the presence of Notch signaling. However, in mammals, there may be multiple co-repressor complexes, rather than the single Hairless co-repressor complex that has been observed in Drosophila. During Notch signaling in all systems, the Notch transmembrane receptor is cleaved and the Notch intracellular domain (NICD) translocates to the nucleus, where it there functions as a specific transcription co-activator for CSL proteins. In the nucleus, NICD replaces the Co-R complex bound to CSL, thus resulting in de-repression of Notch target genes in the nucleus (Figure 2). Once bound to CSL, NICD and CSL proteins recruit an additional co-activator protein, Mastermind, to form a CSL-NICD-Mam ternary co-activator (Co-A) complex. This Co-R complex was initially thought to be sufficient to mediate activation of at least some Notch target genes. However, there now is evidence that still other co-activators and additional DNA-binding transcription factors are required in at least some contexts (reviewed in Barolo, 2002). Thus, CSL is a good example of a bifunctional DNA-binding transcription factor that mediates repression of specific targets genes in one context, but activation of the same targets in another context. This bifunctionality is mediated by the association of specific Co-Repressor complexes vs. specific Co-Activator complexes in different contexts, namely in the absence or presence of Notch signaling."
BMGC_PW0329,BMG_PW1272,"Those metabolic reactions involved in the synthesis of glutathione. Glutathione is a tripeptide that exerts important functions as an antioxidant and in the conjugation of xenobiotics and drugs by phase II biotransformation enzymes. [GO:0006750, PMID:22998389, PMID:23201762, Reactome:R-HSA-174403]",,"The combination of glutamate, cysteine and ATP is required to form glutathione. The steps involved in the synthesis and recycling of glutathione are outlined (Meister, 1988)."
BMGC_PW0330,BMG_PW1276,"Those metabolic reactions involved in the degradation of tryptophan, an essential amino acid. Tryptophan undergoes oxidative catabolism carried out by several hemeprotein enzymes. In plants, tyrosine is the precursor for several secondary metabolites. [GO:0006569, PMID:20817774, PMID:22889220, Reactome:R-HSA-71240]",,Tryptophan is catabolized in seven steps to yield aminomuconate. Intermediates in this process are also used in the synthesis of serotonin and kynurenine (Peters 1991).
BMGC_PW0331,BMG_PW1300,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of steroid hormones. [Reactome:R-HSA-196071]",,"Steroid hormones are synthesized primarily in the adrenal gland and gonads. They regulate energy metabolism and stress responses (glucocorticoids), salt balance (mineralocorticoids), and sexual development and function (androgens and estrogens). All steroids are synthesized from cholesterol. Steroid hormone synthesis is largely regulated at the initial steps of cholesterol mobilization and transport into the mitochondrial matrix for conversion to pregnenolone. In the body, the fate of pregnenolone is tissue-specific: in the zona fasciculata of the adrenal cortex it is converted to cortisol, in the zona glomerulosa to aldosterone, and in the gonads to testosterone and then to estrone and estradiol. These pathways are outlined in the figure below, which also details the sites on the cholesterol molecule that undergo modification in the course of these reactions."
BMGC_PW0332,BMG_PW1307,"Nodal of the Nodal signaling pathway belongs to the transforming growth factor-beta superfamily and plays important roles during vertebrate embryogenesis, where it is involved in pattern formation and differentiation. [GO:0038092, PMID:16838294, Reactome:R-HSA-1181150]",,"Signaling by NODAL is essential for patterning of the axes of the embryo and formation of mesoderm and endoderm (reviewed in Schier 2009, Shen 2007). The NODAL proprotein is secreted and cleaved extracellularly to yield mature NODAL. Mature NODAL homodimerizes and can also form heterodimers with LEFTY1, LEFTY2, or CERBERUS, which negatively regulate NODAL signaling. NODAL also forms heterodimers with GDF1, which increases NODAL activity. NODAL dimers bind the NODAL receptor comprising a type I Activin receptor (ACVR1B or ACVR1C), a type II Activin receptor (ACVR2A or ACVR2B), and an EGF-CFC coreceptor (CRIPTO or CRYPTIC). After binding NODAL, the type II activin receptor phosphorylates the type I activin receptor which then phosphorylates SMAD2 and SMAD3 (R-SMADs). Phosphorylated SMAD2 and SMAD3 form hetero-oligomeric complexes with SMAD4 (CO-SMAD) and transit from the cytosol to the nucleus. Within the nucleus the SMAD complexes interact with transcription factors such as FOXH1 to activate transcription of target genes."
BMGC_PW0333,BMG_PW1312,"The series of events, collectively known as the cell cycle, that underlie the replication of the genome and the segregation of chromosomes into daughter cells. The mitotic cell cycle pathway underlies the generation of new cells. The meiotic cell cycle pathway is a special type of cell division that takes place in germ cells. [GO:0007049, Handbook:Essential_Cell_Biology, Reactome:R-HSA-1640170]","Mitotic cell cycle progression is accomplished through a reproducible sequence of events, DNA replication (S phase) and mitosis (M phase) separated temporally by gaps known as G1 and G2 phases. Cyclin-dependent kinases (CDKs) are key regulatory enzymes, each consisting of a catalytic CDK subunit and an activating cyclin subunit. CDKs regulate the cell's progression through the phases of the cell cycle by modulating the activity of key substrates. Downstream targets of CDKs include transcription factor E2F and its regulator Rb. Precise activation and inactivation of CDKs at specific points in the cell cycle are required for orderly cell division. Cyclin-CDK inhibitors (CKIs), such as p16Ink4a, p15Ink4b, p27Kip1, and p21Cip1, are involved in the negative regulation of CDK activities, thus providing a pathway through which the cell cycle is negatively regulated.              Eukaryotic cells respond to DNA damage by activating signaling pathways that promote cell cycle arrest and DNA repair. In response to DNA damage, the checkpoint kinase ATM phosphorylates and activates Chk2, which in turn directly phosphorylates and activates p53 tumor suppressor protein. p53 and its transcriptional targets play an important role in both G1 and G2 checkpoints. ATR-Chk1-mediated protein degradation of Cdc25A protein phosphatase is also a mechanism conferring intra-S-phase checkpoint activation.","The replication of the genome and the subsequent segregation of chromosomes into daughter cells are controlled by a series of events collectively known as the cell cycle. DNA replication is carried out during a discrete temporal period known as the S (synthesis)-phase, and chromosome segregation occurs during a massive reorganization to cellular architecture at mitosis. Two gap-phases separate these major cell cycle events: G1 between mitosis and S-phase, and G2 between S-phase and mitosis. In the development of the human body, cells can exit the cell cycle for a period and enter a quiescent state known as G0, or terminally differentiate into cells that will not divide again, but undergo morphological development to carry out the wide variety of specialized functions of individual tissues. A family of protein serine/threonine kinases known as the cyclin-dependent kinases (CDKs) controls progression through the cell cycle. As the name suggests, the activity of the catalytic subunit is dependent on binding to a cyclin partner. The human genome encodes several cyclins and several CDKs, with their names largely derived from the order in which they were identified. The oscillation of cyclin abundance is one important mechanism by which these enzymes phosphorylate key substrates to promote events at the relevant time and place. Additional post-translational modifications and interactions with regulatory proteins ensure that CDK activity is precisely regulated, frequently confined to a narrow window of activity. In addition, genome integrity in the cell cycle is maintained by the action of a number of signal transduction pathways, known as cell cycle checkpoints, which monitor the accuracy and completeness of DNA replication during S phase and the orderly chromosomal condensation, pairing and partition into daughter cells during mitosis. Replication of telomeric DNA at the ends of human chromosomes and packaging of their centromeres into chromatin are two aspects of chromosome maintenance that are integral parts of the cell cycle. Meiosis is the specialized form of cell division that generates haploid gametes from diploid germ cells, associated with recombination (exchange of genetic material between chromosomal homologs)."
BMGC_PW0334,BMG_PW1313,"The series of events that take place in the germ cells resulting in the production of four non-identical haploid cells from each diploid cell that enters the cycle. Meiosis involves chromosomal pairing and exchange of DNA segments or recombination. [GO:1903046, Handbook:Essential_cell_Biology, Reactome:R-HSA-1500620]",,"During meiosis the replicated chromosomes of a single diploid cell are segregated into 4 haploid daughter cells by two successive divisions, meiosis I and meiosis II. In meiosis I, the distinguishing event of meiosis, pairs (bivalents) of homologous chromosomes in the form of sister chromatids are paired by synapsis along their regions of homologous DNA (Yang and Wang 2009), and then segregated, resulting in haploid daughters containing sister chromatids paired at their centromeres (Cohen et al. 2006, Handel and Schimenti 2010). The sister chromatids are then separated and segregated during meiosis II. Recombination between chromosomal homologues but not between sister chromatids occurs during prophase of meiosis I (Inagaki et al. 2010). Though hundreds of recombination events are initiated, most are resolved without crossovers and only tens proceed to become crossovers. In mammals recombination events are required between homologues for normal pairing, synapsis, and segregation."
BMGC_PW0335,BMG_PW1318,"The translation pathway that takes place in the mitochondrion. The mitochondrial translation pathway utilizes 22 tRNAs which are encoded in the mitochondrial genome. The mitochondrial genome also encodes 2 ribosomal genes. A small set of mitochondrially-encoded proteins is translated in the mitochondrion. Most others are nuclear genes, synthesized on cytosolic ribosomes and then targeted to the organelle. [GO:0032543, PMID:22258151, PMID:22729854, Reactome:R-HSA-5368287]",,"Of the roughly 1000 human mitochondrial proteins only 13 proteins, all of them hydrophobic inner membrane proteins that are components of the oxidative phosphorylation apparatus, are encoded in the mitochondrial genome and translated by mitoribosomes at the matrix face of the inner membrane (reviewed in Herrmann et al. 2012, Hallberg and Larsson 2014, Lightowlers et al. 2014). The remainder, including all proteins of the mitochondrial translation system, are encoded in the nucleus and imported from the cytosol into the mitochondrion. Translation in the mitochondrion reflects both the bacterial origin of the organelle and subsequent divergent evolution during symbiosis (reviewed in Huot et al. 2014, Richman et al. 2014). Human mitochondrial ribosomes have a low sedimentation coefficient of only 55S, but at 2.71 MDa they retain a similar mass to E. coli 70S particles. The 55S particles are protein-rich compared to both cytosolic ribosomes and eubacterial ribosomes. This is due to shorter mt-rRNAs, mitochondria-specific proteins, and numerous rearrangements in individual protein positions within the two ribosome subunits (inferred from bovine ribosomes in Sharma et al. 2003, Greber et al. 2014, Kaushal et al. 2014, reviewed in Agrawal and Sharma 2012). Mitochondrial mRNAs have either no untranslated leader or short leaders of 1-3 nucleotides, with the exception of the 2 bicistronic transcripts, RNA7 and RNA14, which have overlapping orfs that encode ND4L/ND4 and ATP8/ATP6 respectively. Translation is believed to initiate with the mRNA binding the 28S subunit:MTIF3 (28S subunit:IF-3Mt, 28S subunit:IF2mt) complex together with MTIF2:GTP (IF-2Mt:GTP, IF2mt:GTP) at the matrix face of the inner membrane (reviewed in Christian and Spremulli 2012). MTIF3 can dissociate 55S particles in preparation for initiation, enhances formation of initiation complexes, and inhibits N-formylmethionine-tRNA (fMet-tRNA) binding to 28S subunits in the absence of mRNA. Binding of fMet-tRNA to the start codon of the mRNA results in a stable complex while absence of a start codon at the 5' end of the mRNA causes eventual dissociation of the mRNA from the 28S subunit. After recognition of a start codon, the 39S subunit then binds the stable complex, GTP is hydrolyzed, and the initiation factors MTIF3 and MTIF2:GDP dissociate. Translation elongation then proceeds by cycles of aminoacyl-tRNAs binding, peptide bond formation, and displacement of deacylated tRNAs. In each cycle an aminoacyl-tRNA in a complex with TUFM:GTP (EF-Tu:GTP) binds at the A-site of the ribosome, GTP is hydrolyzed, and TUFM:GDP dissociates. The elongating polypeptide bonded to the tRNA at the P-site is transferred to the aminoacyl group at the A-site by peptide bond formation at the peptidyl transferase center, leaving a deacylated tRNA at the P-site and the elongating polypeptide attached to the tRNA at the A-site. The polypeptide is co-translationally inserted into the inner mitochondrial membrane via an interaction with OXA1L (Haque et al. 2010, reviewed in Ott and Hermann 2010). After peptide bond formation, GFM1:GTP (EF-Gmt:GTP) then binds the ribosome complex, GTP is hydrolyzed, GFM1:GDP dissociates, and the ribosome translocates 3 nucleotides in the 3' direction along the mRNA, relocating the polypeptide-tRNA to the P-site and allowing another cycle to begin. TUFM:GDP is regenerated to TUFM:GTP by the guanine nucleotide exchange factor TSFM (EF-Ts, EF-TsMt). Translation is terminated when MTRF1L:GTP (MTRF1a:GTP) recognizes an UAA or UAG termination codon at the A-site of the ribosome (Tsuboi et al. 2009). GTP hydrolysis does not appear to be required. The tRNA-aminoacyl bond between the translated polypeptide and the final tRNA at the P-site is hydrolyzed by the 39S subunit, facilitating release of the polypeptide. MRRF (RRF) and GFM2:GTP (EF-G2mt:GTP) then act to release the remaining tRNA and mRNA from the ribosome and dissociate the 55S ribosome into 28S and 39S subunits. Mutations have been identified in genes encoding mitochondrial ribosomal proteins and translation factors. These have been shown to be pathogenic, causing neurological and other diseases (reviewed in Koopman et al. 2013, Pearce et al. 2013)."
BMGC_PW0336,BMG_PW1319,"Aminoacyl-tRNA, or transfer RNA (tRNA) carries amino acids to ribosomes and is part of the translation pathway. tRNAs are specific for the amino acids with which they are associated. Their synthesis involves adenylation of the amino acid followed by its transfer; both steps require ATP. There are 22 tRNA genes encoded by the mitochondrial genome. Mutations in these genes have been implicated in a number of disorders and may affect various steps of tRNA biosynthesis. [GO:0070127, PMID:22258151, Reactome:R-HSA-379726]",,"Mitochondrial tRNA synthetases act in the mitochondrial matrix to catalyze the reactions of tRNAs encoded in the mitochondrial genome, their cognate amino acids, and ATP to form aminoacyl-tRNAs, AMP, and pyrophosphate (Schneider et al. 2000). The synthetase enzymes that catalyze these reactions are all encoded in the nuclear genome. In three cases, glycine, lysine, and glutamine, a single gene encodes two enzyme isoforms, one cytosolic and one mitochondrial. All other mitochondrial tRNA synthetases are encoded by genes different from the ones encoding the corresponding cytosolic enzymes."
BMGC_PW0337,BMG_PW1326,"RNA polymerase II transcription elongation commences when the nascent transcript reaches about 25 residues. Some general transcription factors are released and the RNA polymerase II carries out elongation of the pre-mRNA transcript and proofreading. Various regulators control early elongation, proximal promoter pausing and full elongation proceedings. Nascent mRNA processing, splicing and alternative splicing are co-occurring. [GO:0006368, PMID:22975042, PMID:23000482, PMID:23046879, Reactome:R-HSA-75955]",,"The mechanisms governing the process of elongation during eukaryotic mRNA synthesis are being unraveled by recent studies. These studies have led to the expected discovery of a diverse collection of transcription factors that directly regulate the activities of RNA Polymerase II and unexpected discovery of roles for many elongation factors in other basic processes like DNA repair, recombination, etc. The transcription machinery and structural features of the major RNA polymerases are conserved across species. The genes active during elongation fall under different classes like, housekeeping, cell-cycle regulated, development and differentiation specific genes etc. The list of genes involved in elongation has been growing in recent times, and include: -TFIIS,DSIF, NELF, P-Tefb etc. that are involved in drug induced or sequence-dependent arrest - TFIIF, ELL, elongin, elongator etc. that are involved in increasing the catalytic rate of elongation by altering the Km and/or the Vmax of Pol II -FACT, Paf1 and other factors that are involved chromatin modification - DNA repair proteins, RNA processing and export factors, the 19S proteasome and a host of other factors like Spt5-Spt5, Paf1, and NELF complexes, FCP1P etc. (Arndt and Kane, 2003). Elongation also represents processive phase of transcription in which the activities of several mRNA processing factors are coupled to transcription through their binding to RNA polymerase (Pol II). One of the key events that enables this interaction is the differential phosphorylation of Pol II CTD. Phosphorylation pattern of CTD changes during transcription, most significantly at the beginning and during elongation process. TFIIH-dependent Ser5 phosphorylation is observed primarily at promoter regions while P-Tefb mediated Ser2 phosphorylation is seen mainly in the coding regions, during elongation. Experimental evidence suggests a dynamic association of RNA processing factors with differently modified forms of the polymerase during the transcription cycle. (Komarnitsky et al., 2000). [Komarnitsky et al 2000, Arndt & Kane 2003, Shilatifard et al 2003]"
BMGC_PW0338,BMG_PW1327,"Termination of transcription is important for partitioning the genome and maintaining adequate expression of neighboring genes. [GO:0006386, PMID:21487437, Reactome:R-HSA-73856]",,"This section includes the cleavage of both polyadenylated and non-polyadenylated transcripts. In the former case polyadenylation has to precede transcript cleavage, while in the latter case there is no polyadenylation."
BMGC_PW0339,BMG_PW1353,"Those metabolic reactions involved in the synthesis of coenzyme A. The five-step reaction pathway requires pantothenate (vitamin B5) and cysteine as precursors. [GO:0015937, PMID:11923312, Reactome:R-HSA-196783]",,Coenzyme A (CoA) is a ubiquitous cofactor that functions as an acyl group carrier in diverse processes including fatty acid metabolism and the TCA cycle (Lipmann 1953). It is synthesized from the vitamin pantothenate in a sequence of five reactions (Daugherty et al. 2002; Leonardi et al. 2005; Robishaw and Neely 1985). These reactions all occur in the cytosol or the mitochondrial intermembrane space (Leonardi et al. 2005). A recently described transport protein appears to mediate the uptake of Coenzyme A into the mitochondrial matrix (Prohl et al. 2001).
BMGC_PW0340,BMG_PW1370,"Those metabolic reactions involved in the synthesis of nicotinamide adenine dinucleotide (NAD) from precursors such as nicotinamide, nicotinic acid or nicotinamide riboside, collectively known as vitamin B3 or niacin. [GO:0034356, PMID:18020963, PMID:20007326, PMID:26785480, Reactome:R-HSA-197264]",,"Nicotinamide (NAM) levels are modulated by the action of three enzymes involved in nicotinamide salvaging. They are nicotinamide deaminase, nicotinamide phosphoribosyltransferase and nicotinate phosphoribosyltransferase. These enzymes are poorly characterized in humans, depsite their importance in NAM utilization (Magni et al. 2004). Although not a salvage reaction, NAM levels can also be regulated by nicotinamide N-methyltransferase (NNMT), a potential regulator of diet-induced obesity (Kraus et al. 2014)."
BMGC_PW0341,BMG_PW1467,"Those diseases and disorders that are caused by deregulation of a metabolic pathway. It can be due to an inherited defect in an enzyme function and thus congenital, or acquired, when resulting from the failure or malfunctioning of an important metabolic organ. [MeSH:D008659, Reactome:R-HSA-5668914]",,"Metabolic processes in human cells generate energy through the oxidation of molecules consumed in the diet and mediate the synthesis of diverse essential molecules not taken in the diet as well as the inactivation and elimination of toxic ones generated endogenously or present in the extracellular environment. Mutations that disrupt these processes by inactivating a required enzyme or regulatory protein, or more rarely by changing its specificity can lead to severe diseases. Metabolic diseases annotated here involve aspects of carbohydrate, glycosylation, amino acid (phenylketonuria), surfactant and vitamin metabolism, and biological oxidations. One somatic mutation that affects cytosolic isocitrate metabolism, often found in glioblastomas and some lymphoid neoplasms, is also annotated. Also described are mutated forms of adrenocorticotropic hormone (ACTH) that can lead to obesity, resulting in excessive accumulation of body fat."
BMGC_PW0342,BMG_PW1490,"Alterations in the visual phototransduction signaling have been linked to a number conditions such as retinits pigmentosa (RP), Bardet-Biedl syndrome (BBS), macular degeneration and others. More than 200 point mutations in rhodopsin account for ~25% of the autosomal dominant type of RP. [PMID:20212494, PMID:23684651, Reactome:R-HSA-2474795]",,"The process of vision involves two stages; the retinoid cycle which supplies and regenerates the visual chromophore required for vision and phototransduction which propagates the light signal. Defects in the genes involved in the retinoid cycle cause degenerative retinal diseases. These defective genes are described here (for reviews see Travis et al. 2007, Palczewski 2010, Fletcher et al. 2011, den Hollander et al. 2008)."
BMGC_PW0343,BMG_PW1493,"Alteration in the retinoid cycle, or the visual cycle, have been associated with retinitis pigmentosa and a few other forms of photoreceptor degeneration. [PMID:20212494, PMID:23684651, Reactome:R-HSA-2453864]",,"The gene defects which cause diseases related to the retinoid cycle are described here (Travis et al. 2007, Palczewski 2010, Fletcher et al. 2011, den Hollander et al. 2008)."
BMGC_PW0344,BMG_PW1510,"The Hippo signaling pathway plays important roles in organ development and growth and tumor suppression. The pathway consists of a core of four kinases which once activated by upstream regulators promote the cytoplasmic sequestration of YAP/TAZ transcriptional regulators. Dysregulation of the pathway has been implicated in tumor metastasis. [GO:0035329, PMID:23312716, PMID:23431053, PMID:26045258, Reactome:R-HSA-2028269]","Hippo signaling pathways control diverse aspects of cell proliferation, survival, and morphogenesis in eukaryotes. The core organization of these networks is conserved over a billion years of evolution, with related forms described in animals and fungi. In Drosophila and mammals, Hippo/MST co-operate with Mats/Mob1 and Salvador/WW45 to activate Warts/LATS, which negatively regulates Yorkie/YAP. Yorkie/YAP interact with Scalloped/TEAD to promote gene transcriptions and control organ size through the balance between cell proliferation and apoptosis. In C. elegans, WTS-1 YAP-1 EGL-44 axis is conserved and regulates thermotolerance and healthy lifespan. In S. cerevisiae, the LATS-related Dbf2 or Dbf20 kinase in complex with Mob1 controls mitotic exit and cytokinesis, and the Hippo/MST family of kinases, STE-20, modulates Tec1, the putative yeast TEAD ortholog.","Human Hippo signaling is a network of reactions that regulates cell proliferation and apoptosis, centered on a three-step kinase cascade. The cascade was discovered by analysis of Drosophila mutations that lead to tissue overgrowth, and human homologues of its components have since been identified and characterized at a molecular level. Data from studies of mice carrying knockout mutant alleles of the genes as well as from studies of somatic mutations in these genes in human tumors are consistent with the conclusion that in mammals, as in flies, the Hippo cascade is required for normal regulation of cell proliferation and defects in the pathway are associated with cell overgrowth and tumorigenesis (Oh and Irvine 2010; Pan 2010; Zhao et al. 2010). This group of reactions is also notable for its abundance of protein:protein interactions mediated by WW domains and PPxY sequence motifs (Sudol and Harvey 2010). There are two human homologues of each of the three Drosophila kinases, whose functions are well conserved: expression of human proteins rescues fly mutants. The two members of each pair of human homologues have biochemically indistinguishable functions. Autophosphorylated STK3 (MST2) and STK4 (MST1) (homologues of Drosophila Hippo) catalyze the phosphorylation and activation of LATS1 and LATS2 (homologues of Drosophila Warts) and of the accessory proteins MOB1A and MOB1B (homologues of Drosophila Mats). LATS1 and LATS2 in turn catalyze the phosphorylation of the transcriptional co-activators YAP1 and WWTR1 (TAZ) (homologues of Drosophila Yorkie). In their unphosphorylated states, YAP1 and WWTR1 freely enter the nucleus and function as transcriptional co-activators. In their phosphorylated states, however, YAP1 and WWTR1 are instead bound by 14-3-3 proteins, YWHAB and YWHAE respectively, and sequestered in the cytosol. Several accessory proteins are required for the three-step kinase cascade to function. STK3 (MST2) and STK4 (MST1) each form a complex with SAV1 (homologue of Drosophila Salvador), and LATS1 and LATS2 form complexes with MOB1A and MOB1B (homologues of Drosophila Mats). In Drosophila a complex of three proteins, Kibra, Expanded, and Merlin, can trigger the Hippo cascade. A human homologue of Kibra, WWC1, has been identified and indirect evidence suggests that it can regulate the human Hippo pathway (Xiao et al. 2011). A molecular mechanism for this interaction has not yet been worked out and the molecular steps that trigger the Hippo kinase cascade in humans are unknown. Four additional processes related to human Hippo signaling, although incompletely characterized, have been described in sufficient detail to allow their annotation. All are of physiological interest as they are likely to be parts of mechanisms by which Hippo signaling is modulated or functionally linked to other signaling processes. First, the caspase 3 protease cleaves STK3 (MST2) and STK4 (MST1), releasing inhibitory carboxyterminal domains in each case, leading to increased kinase activity and YAP1 / TAZ phosphorylation (Lee et al. 2001). Second, cytosolic AMOT (angiomotin) proteins can bind YAP1 and WWTR1 (TAZ) in their unphosphorylated states, a process that may provide a Hippo-independent mechanism to down-regulate the activities of these proteins (Chan et al. 2011). Third, WWTR1 (TAZ) and YAP1 bind ZO-1 and 2 proteins (Remue et al. 2010; Oka et al. 2010). Fourth, phosphorylated WWTR1 (TAZ) binds and sequesters DVL2, providing a molecular link between Hippo and Wnt signaling (Varelas et al. 2010)."
BMGC_PW0345,BMG_PW1516,"Those metabolic reactions involved in the biosynthesis of dermatan sulfate - a mucopolysaccharide found primarily in skin but also in tendons, lungs, heart valves and blood vessels. [GO:0030208, http://en.wikipedia.org/wiki/Dermatan_sulfate wikipedia, Reactome:R-HSA-2022923]",,"Dermatan sulfate (DS) consists of N-acetylgalactosamine (GalNAc) residues alternating in glycosidic linkages with glucuronic acid (GlcA) or iduronic acid (IdoA) residues. As with CS, GalNAc residues can be sulfated in CS chains but also the uronic acid residues may be substituted with sulfate at the 2- and 4- positions. The steps below outline the synthesis of a simple DS chain (Silbert & Sugumaran 2002)."
BMGC_PW0346,BMG_PW1521,"Thromboxane is one of several families of prostanoids, eicosanoids derived from omega-3 or omega-6 fatty acids. Of the two thromboxane molecules, only A2 has activity. Thromboxane A2 signaling exerts vasoconstrictor and platelet aggregation roles. Its actions oppose those of prostaglandin I2, the other important prostanoid for cardiovascular system homeostasis. [GO:0038193, PMID:12955468, PMID:23063076, Reactome:R-HSA-428930]",,"Thromboxane (TXA2) binds to the thromboxane receptor (TP). There are 2 splice variant forms of TP, differing in their cytoplasmic carboxyl terminal tails. TP beta was first identified in endothelial cells. TP alpha was identified in platelets and placenta. The major signalling route for TP is Gq-mediated stimulation of PLC and consequent increase in cellular calcium. TP also couples to G13, leading to stimulation of Rho and Rac."
BMGC_PW0347,BMG_PW1551,"Programmed cell death pathways group together several types that can be described as apoptotic or non-apoptotic, based on morphological characteristics. The common feature is their highly regulated nature, as opposed to accidental, non-programmed cell death. [GO:0012501, PMID:11965491, PMID:21760595, PMID:23030059, Reactome:R-HSA-5357801]",,"Cell death is a fundamental cellular response that has a crucial role in shaping our bodies during development and in regulating tissue homeostasis by eliminating unwanted cells. There are a number of different forms of cell death, each with a corresponding number of complex subprocesses. The first form of regulated or programmed cell death to be characterized was apoptosis. Evidence has emerged for a number of regulated non-apoptotic cell death pathways, including some with morphological features that were previously attributed to necrosis. More recently necrosis has been subdivided into parts including programmed necrotic cell death processes, such as RIP1-mediated regulated necrosis or pyroptosis. Reactome currently represents programmed cell death using the model of extrinsic signalling that leads to a molecular decision point pivoting on caspase-8 activation or inhibition. Caspase-8 activation tilts the cell towards apoptosis, while caspase-8 inhibition tilts the cell towards Regulated Necrosis. The terminology and molecular definitions of cell death-related events annotated here are consistent with the 2015 recommendations of the Nomenclature Committee on Cell Death (NCCD) (Galluzzi L et al. 2015)."
BMGC_PW0348,BMG_PW1564,"Initiation of transcription from the bipartite rDNA repeats requires the assembly of the Pol I preinitiation complex (PIC) and subsequent recruitment of the polymerase. [GO:0006361, PMID:22960599, Reactome:R-HSA-73762]",,During initiation the double-stranded DNA must be melted and transcription begins. SL1 forms and interacts with UBF-1 and the rDNA promoter. It is this platform that will recruit active RNA polymerase I to the SL1:phosphorlated UBF-1:rDNA promoter complex. Mammalian rRNA genes are preceded by a terminator element that is recognized by the SL1 complex. This SL1 modulated acetylation of the basal Pol I transcription machinery has functional consequences suggesting that the reversible acetylation may be one way to regulate rDNA transcription.
BMGC_PW0349,BMG_PW1565,"Subunits of Pol I have elongation and hydrolysis capabilities. However, additional trans-acting factors are involved in Pol I elongation steps. [GO:0006362, PMID:21893173, Reactome:R-HSA-73777]",,
BMGC_PW0350,BMG_PW1566,"Termination of transcription by the polymerase I system requires the recruitment of specific factors to particular DNA elements. [GO:0006363, PMID:23092677, Reactome:R-HSA-73863]",,Termination of transcription by RNA polymerase I is a 4 step process. Initially TTF-1 binds the template rDNA. This complex pauses polymerase I allowing PTRF to interact with the quaternary complex releasing both pre-rRNA and Pol I from the template and TTF-1.
BMGC_PW0351,BMG_PW1567,"Processing of the initial tRNA transcript, including splicing of intron-containing pre-tRNAs and multiple modifications to produce the mature tRNA molecule that is exported to the cytoplasm. [GO:0008033, PMID:21915787, PMID:23545199, Reactome:R-HSA-72306]",,"Genes encoding transfer RNAs (tRNAs) are transcribed by RNA polymerase III in the nucleus and by mitochondrial RNA polymerase in the mitochondrion. In the nucleus transcription reactions produce precursor tRNAs (pre-tRNAs) that have extra 5' leaders, 3' trailers, and, in some cases, introns which are removed by enzymes and enzyme complexes: RNase P cleaves the 5' leader, RNase Z cleaves the 3' trailer, TRNT1 polymerizes CCA onto the resulting 3' end, the TSEN complex cleaves at each end of the intron, and the tRNA ligase complex ligates the resulting exons (reviewed in Rossmanith et al. 1995, Phizicky and Hopper 2010, Suzuki et al. 2011, Abbott et al. 2014, Li and Mason 2014). The nucleotides within tRNAs undergo further chemical modifications such as methylation and deamination by a diverse set of enzymes (reviewed in Helm and Alfonzo 2014, Boschi-Muller and Motorin 2013). The order of events for each tRNA is not fully known and the understanding of the overall process is complicated by the retrograde (cytosol to nucleus) transport of tRNAs. In the mitochondrial matrix transcription produces long precursor RNAs, H strand transcripts and an L strand transcript, that are cleaved by mitochondrial RNase P (an entirely proteinaceous complex), ELAC2, and other nucleases to yield 12S rRNA, 16S rRNA, mRNAs, and pre-tRNAs lacking 3' CCA sequences (reviewed in Van Haute et al. 2015). TRNT1 polymerizes an untemplated CCA sequence onto the 3' ends of the pre-tRNAs and chemical modifications are made to several nucleotides in the tRNAs."
BMGC_PW0352,BMG_PW1568,"The reactions involved in processing the primary Pol I-transcribed rRNA and the 5S pre-rRNA transcribed by Pol III. The large Pol I transcribed pre-rRNA contains the mature 18S, 5.8S and 25S/28S rRNAs separated by internal (ITS) and flanked by external transcribed spacers (ETS). The nascent pre-rRNA associates co-transcriptionally with various factors, folds and is modified, while endo- and exo-nucleolytic cleavages sequentially remove the spacers. Cleavage at site ITS1 separates the initial 90S pre-ribosome into pre-40S and pre-60S particles whose nucleocytoplasmic processing will follow independent routes. [GO:0006364, PMID:17509569, PMID:25346433, Reactome:R-HSA-72312]",,"Each eukaryotic cytosolic ribosome contains 4 molecules of RNA: 28S rRNA (25S rRNA in yeast), 5.8S rRNA, and 5S rRNA in the 60S subunit and 18S rRNA in the 40S subunit. The 18S rRNA, 5.8S rRNA, and 28S rRNA are produced by endonucleolytic and exonucleolytic processing of a single 47S precursor (pre-rRNA) (reviewed in Henras et al. 2015). Transcription of ribosomal RNA genes, processing of pre-rRNA, and assembly of precursor 60S and 40S subunits occur in the nucleolus (reviewed in Hernandez-Verdun et al. 2010), with a few late reactions occurring in the cytosol. Within the nucleolus non-transcribed DNA and inactive polymerase complexes are located in the fibrillar center, active DNA polymerase I transcription occurs at the interface between the fibrillar center and the dense fibrillar component, early processing of pre-rRNA occurs in the dense fibrillar component, and late processing of pre-rRNA occurs in the granular component (Stanek et al. 2001). Processed ribosomal RNA contains many modified nucleotides which are generated by enzymes acting on encoded nucleotides contained in the precursor rRNA (reviewed in Boschi-Muller and Motorin 2013). The most numerous modifications are pseudouridine residues and 2'-O-methylribonucleotides. Pseudouridylation is guided by base pairing between the precursor rRNA and a small nucleolar RNA (snoRNA) in a Box C/D snoRNP (reviewed in Henras et al 2004, Yu and Meier 2014). Similarly, 2'-O-methylation is guided by base pairing between the precursor rRNA and a snoRNA in a Box H/ACA snoRNP (reviewed in Henras et al. 2004, Hamma and Ferre-D'Amare 2010). Other modifications include N(1)-methylpseudouridine, 5-methylcytosine, 7-methylguanosine, 6-dimethyladenosine, and 4-acetylcytidine. Modification of nucleotides occur as the pre-rRNA is being cleaved. However, the order of cleavage and modification steps is not clear so these two processes are presented separately here. Defects in ribosome biogenesis factors can cause disease (reviewed in Freed et al. 2010). Mitochondrial ribosomes are completely distinct from cytoplasmic ribosomes, having different protein subunits and 12S rRNA and 16S rRNA. The mitochondrial rRNAs are encoded in the mitochondrial genome and are produced by processing of a long H strand transcript. Specific residues in the rRNAs are modified by enzymes to yield 5 different types of modified nucleotides:"
BMGC_PW0353,BMG_PW1590,"The pathway of processing - absorption, distribution, metabolism or elimination - of abacavir, a drug used for the treatment of HIV. Genetic variations can result in changes in the availability of the drug. [PMID:18479171, Reactome:R-HSA-2161522]",,"Abacavir is a nucleoside analogue reverse transcriptase inhibitor with antiretroviral activity, widely used in combination with other drugs to treat HIV-1 infection (Yuen et al. 2008). Its uptake across the plasma membrane is mediated by organic cation transporters SLC22A1, 2, and 3; the transport proteins ABCB1 and ABCG2 mediate its efflux. Abacavir itself is a prodrug. Activation requires phosphorylation by a cytosolic adenosine phosphotransferase and deamination by ADAL deaminase to yield carbovir monophosphate. Cytosolic nucleotide kinases convert carbovir monophosphate to carbovir triphosphate, the active HIV reverse transcriptase inhibitor. Abacavir can be glucuronidated or oxidized to a 5'-carboxylate; these are the major forms in which it is excreted from the body."
BMGC_PW0354,BMG_PW1752,"The insulin precursor, preproinsulin is subject to several processing steps in the endoplasmic reticulum and the Golgi apparatus before ending as the mature zinc-insulin hexamer stored in secretory granules. The expression of insulin is confined to the beta cells of the pancreatic islets of Langerhans. [GO:0030070, PMID:24843567, Reactome:R-HSA-264876]",,"Generation of insulin containing secretory granules from newly synthesized proinsulin in the lumen of the endoplasmic reticulum (ER) involves formation of proinsulin intramolecular disulfide bonds, formation of proinsulin zinc calcium complexes, proteolytic cleavage of proinsulin to yield insulin and C peptide, and translocation of the granules across the cytosol to the plasma membrane (Dodson & Steiner 1998). Transcription of the human insulin gene INS is annotated as part of the pathway “Regulation of gene expression in beta cells” (see reaction R-HSA-211289). The preproinsulin mRNA is translated by ribosomes at the rough endoplasmic reticulum (ER) and the preproinsulin enters the secretion pathway by virtue of its signal peptide, which is co-translationally cleaved to yield proinsulin. In the process annotated here, within the ER, three intramolecular disulfide bonds form in proinsulin, mediated by P4HD (PDI1A) and ERO1B proteins. Correctly folded, disulfide-bonded proinsulin then moves via vesicles from the ER to the Golgi Complex where it forms complexes with zinc and calcium. Proinsulin zinc calcium complexes bud in vesicles from the trans Golgi to form immature secretory vesicles (secretory granules) in the cytosol. Within the immature granules, endoproteases PCKS1 and PCKS2 (Prohormone Convertases 1 and 2) cleave proinsulin at two sites and CPE (Carboxypeptidase E) removes additional amino acid residues to yield the cystine bonded A and B chains of mature insulin and the C peptide, which will be secreted with the insulin. The insulin zinc calcium complexes form insoluble crystals within the granule. The insulin containing secretory granules are then translocated across the cytosol to the inner surface of the plasma membrane. Translocation occurs initially by attachment of the granules to Kinesin 1, which motors along microtubules, and then by attachment to Myosin Va, which motors along the microfilaments of the cortical actin network. A pancreatic beta cell contains about 10,000 insulin granules of which about 1,000 are docked at the plasma membrane and 50 are readily releasable in immediate response to stimulation by glucose or other secretogogues. Docking is due to interaction between the Exocyst proteins EXOC3 on the granule membrane and EXOC4 on the plasma membrane. Exocytosis is accomplished by interaction between SNARE type proteins Syntaxin 1A and Syntaxin 4 on the plasma membrane and Synaptobrevin 2/VAMP2 on the granule membrane. Exocytosis is a calcium dependent process due to interaction of the calcium binding membrane protein Synaptotagmin V/IX with the SNARE type proteins."
BMGC_PW0355,BMG_PW1836,"Damage to mitochondria will promote mitophagy, the mitochondrial autophagy pathway. It exhibits features common to macroautophagy or the regular autophagy, and also features that are distinct. Under more sustained stress, the cell will promote apoptosis. Translocation of cardiolipin, the signature phospholipid of the mitochondrial inner membrane, to the outer membrane, provides a signal of mitochondrial dysfunction. [GO:0000423, PMID:22743996, PMID:23065344, PMID:25673287, PMID:25840011, Reactome:R-HSA-5205647]","Mitochondria act as the energy powerhouse of the cell, and are essential for eukaryotic cells to grow and function normally. However, deleterious byproducts of oxidative phosphorylation process called reactive oxidative species (ROS) lead to mitochondrial dysfunction. If the damage is too excessive to be repaired, such mitochondria are selectively recognized and targeted for degradation by a specific mode of autophagy, termed mitophagy. The loss of the mitochondrial membrane potential can induce mitophagy, involving the kinase PINK1 and the E3 ligase Parkin. PINK1 serves as the sensor for the mitochondrial depolarization and recruits Parkin, followed by ubiquitin-dependent recruitment of mitophagy receptors. There are also several PINK1/Parkin-independent mitophagy pathways, in which a group of LIR-containing receptors are required in response to different stimuli. Mitophagy contributes to the maintenance of a healthy mitochondrial network and the prevention of programmed cell death.","Mitophagy is a specific form of autophagy where mitochondria are specifically targeted for degradation by autophagolysosomes. In mammals there are a number of known mechanisms of mitophagy. One ensures maternal inheritance of mitochondrial DNA through the elimination of sperm derived mitochondria. A second is elimination of functional mitochondria during erythrocyte maturation and eye lens maturation. It is established that the outer mitochondrial membrane receptor Nix (or Bnip3l) and autophagosome associated protein LC3 are important for mitochondrial degradation in erythrocytes. A third mechanism is driven by the PINK1 and Parkin (PRKN) proteins. PRKN is recruited to the mitochondria when the mitochondrial membrane potential is reduced due to uncoupling, thereby initiating mitophagy."
BMGC_PW0356,BMG_PW1948,"Nuclear eukaryotic DNA replication takes place in the context of the cell cycle during the S-phase. The fast and accurate replication of DNA requires the presence and the coordinated function of a complex of proteins known as the replisome. The exact composition of the replisome in higher organisms still has to be fully determined. Mitochondria contain their own DNA. Human mtDNA is a small, circular molecule that resides in the matrix and, depending on cell type, can exist as a few to several thousands copies. mtDNA has its own replicative machinery. [GO:0044786, https://en.wikipedia.org/wiki/DNA_replication wikipedia, https://en.wikipedia.org/wiki/Mitochondrial_DNA wikipedia, PMID:19665592, Reactome:R-HSA-69306]","A complex network of interacting proteins and enzymes is required for DNA replication. Generally, DNA replication follows a multistep enzymatic pathway. At the DNA replication fork, a DNA helicase (DnaB or MCM complex) precedes the DNA synthetic machinery and unwinds the duplex parental DNA in cooperation with the SSB or RPA. On the leading strand, replication occurs continuously in a 5 to 3 direction, whereas on the lagging strand, DNA replication occurs discontinuously by synthesis and joining of short Okazaki fragments. In prokaryotes, the leading strand replication apparatus consists of a DNA polymerase (pol III core), a sliding clamp (beta), and a clamp loader (gamma delta complex). The DNA primase (DnaG) is needed to form RNA primers. Normally, during replication of the lagging-strand DNA template, an RNA primer is removed either by an RNase H or by the 5 to 3 exonuclease activity of DNA pol I, and the DNA ligase joins the Okazaki fragments. In eukaryotes, three DNA polymerases (alpha, delta, and epsilon) have been identified. DNA primase forms a permanent complex with DNA polymerase alpha. PCNA and RFC function as a clamp and a clamp loader. FEN 1 and RNase H1 remove the RNA from the Okazaki fragments and DNA ligase I joins the DNA.","Studies in the past decade have suggested that the basic mechanism of DNA replication initiation is conserved in all kingdoms of life. Initiation in unicellular eukaryotes, in particular Saccharomyces cerevisiae (budding yeast), is well understood, and has served as a model for studies of DNA replication initiation in multicellular eukaryotes, including humans. In general terms, the first step of initiation is the binding of the replication initiator to the origin of replication. The replicative helicase is then assembled onto the origin, usually by a helicase assembly factor. Either shortly before or shortly after helicase assembly, some local unwinding of the origin of replication occurs in a region rich in adenine and thymine bases (often termed a DNA unwinding element, DUE). The unwound region provides the substrate for primer synthesis and initiation of DNA replication. The best-defined eukaryotic origins are those of S. cerevisiae, which have well-conserved sequence elements for initiator binding, DNA unwinding and binding of accessory proteins. In multicellular eukaryotes, unlike S. cerevisiae, these loci appear not to be defined by the presence of a DNA sequence motif. Indeed, choice of replication origins in a multicellular eukaryote may vary with developmental stage and tissue type. In cell-free models of metazoan DNA replication, such as the one provided by Xenopus egg extracts, there are only limited DNA sequence specificity requirements for replication initiation (Kelly & Brown 2000; Bell & Dutta 2002; Marahrens & Stillman 1992; Cimbora & Groudine 2001; Mahbubani et al 1992, Hyrien & Mechali 1993)."
BMGC_PW0357,BMG_PW1956,"Mitochondria are essential organelles that provide most of the ATP fuel for the cell, are the site of several important metabolic pathways and play essential roles in calcium storage, signaling and apoptosis. Of the many proteins involved, only 13 are encoded in the mammalian mitochondrial DNA. The remaining ~99% of mitochondrial proteins are translocated from the cytosol via a complex, multicomponent pathway system. Mitochondria-encoded proteins are translocated from the mitochondrial matrix into the inner mitochondrial membrane by a single system. [GO:0006626, PMID:22178138, PMID:24561263, PMID:25633533, Reactome:R-HSA-1268020]",,"A human mitochondrion contains about 1500 proteins, more than 99% of which are encoded in the nucleus, synthesized in the cytosol and imported into the mitochondrion. Proteins are targeted to four locations (outer membrane, intermembrane space, inner membrane, and matrix) and must be sorted accordingly (reviewed in Kutik et al. 2007, Milenkovic et al. 2007, Bolender et al. 2008, Endo and Yamano 2009, Wiedemann and Pfanner 2017, Kang et al. 2018). Newly synthesized proteins are transported from the cytosol across the outer membrane by the TOMM40:TOMM70 complex. Proteins that contain presequences first interact with the TOMM20 subunit of the complex while proteins that contain internal targeting elements first interact with the TOMM70 subunit. After initial interaction the protein is conducted across the outer membrane by TOMM40 subunits. In yeast some proteins such as Aco1, Atp1, Cit1, Idh1, and Atp2 have both presequences that interact with TOM20 and mature regions that interact with TOM70 (Yamamoto et al. 2009). After passage across the outer membrane, proteins may be targeted to the outer membrane via the SAMM50 complex, to the inner membrane via the TIMM22 or TIMM23 complexes (reviewed in van der Laan et al. 2010), to the matrix via the TIMM23 complex (reviewed in van der Laan et al. 2010), or proteins may fold and remain in the intermembrane space (reviewed in Stojanovski et al. 2008, Deponte and Hell 2009, Sideris and Tokatlidis 2010). Presequences on matrix and inner membrane proteins cause interaction with TIMM23 complexes; internal targeting sequences cause outer membrane proteins to interact with the SAMM50 complex and inner membrane proteins to interact with the TIMM22 complex. While in the intermembrane space hydrophobic proteins are chaperoned by the TIMM8:TIMM13 complex and/or the TIMM9:TIMM10:FXC1 complex."
BMGC_PW0358,BMG_PW1985,"A group of inherited metabolic disorders resulting from alterations in the glycogen metabolic pathway. [MeSH:D006008, Reactome:R-HSA-3229121]",,"The regulated turnover of glycogen plays a central, tissue-specific role in the maintenance of blood glucose levels and in the provision of glucose to tissues such as muscle and brain in response to stress. Defects in the enzymes involved in glycogen turnover are associated with abnormal responses to fasting and exercise that can differ widely in their presentation and severity. Additional symptoms can be the result of accumulation of abnormal products of glycogen metabolism (Hauk et al. 1959; Hers 1964; Shin 2006). Annotations are provided here for diseases due to deficiencies of GYS1 and GYS1 (glycogen synthase 1 and 2; glycogen storage disease type 0 (GSD type 0), of G6PC (glucose-6-phosphatase, GSD type Ia) and the SLC37A4 transporter (GSD type Ib), of GAA (lysosomal acid alpha-glucosidase, GSD type II), of GBE1 (glycogen branching enzyme, GSD type IV), and of GYG1 (glycogenin 1, GSD XV). Two additional diseases, myoclonic epilepsy of Lafora (Roach et al. 2012) and severe congenital neutropenia type 4 (Boztug et al. 2009), are included as they are due to defects in enzymes of glycogen metabolism."
BMGC_PW0359,BMG_PW2279,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of porphyrins. Porphyrins represent a group of heterocyclic macrocycle organic compounds. Many are naturally occurring and one best example is the red blood cell heme pigment. [GO:0006778, https://en.wikipedia.org/wiki/Porphyrin wikipedia, Reactome:R-HSA-189445, SMP:00024]",,"Porphyrins are heterocyclic macrocycles, consisting of four pyrrole subunits (tetrapyrrole) linked by four methine (=CH-) bridges. The extensive conjugated porphyrin macrocycle is chromatic and the name itself, porphyrin, is derived from the Greek word for purple. The aromatic character of porphyrins can be seen by NMR spectroscopy. Porphyrins readily combine with metals by coordinating them in the central cavity. Iron (heme) and magnesium (chlorophyll) are two well known examples although zinc, copper, nickel and cobalt form other known metal-containing phorphyrins. A porphyrin which has no metal in the cavity is called a free base. Some iron-containing porphyrins are called hemes (heme-containing proteins or hemoproteins) and these are found extensively in nature ie. hemoglobin. Hemoglobin is quantitatively the most important hemoprotein. The hemoglobin iron is the transfer site of oxygen and carries it in the blood all round the body for cell respiration. Other examples are cytochromes present in mitochondria and endoplasmic reticulum which takes part in electron transfer events, catalase and peroxidase whic protect the body against the oxidant hydrogen peroxide and tryptophan oxygenase which is present in intermediary metabolism. Hemoproteins are synthesized in all mammalian cells and the major sites are erythropoietic tissue and the liver. The processes by which heme is synthesized, transported, and metabolized are a critical part of human iron metabolism (Severance and Hamze 2009); here the core processes of heme biosynthesis and catabolism have been annotated."
BMGC_PW0360,BMG_PW2285,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of carnitine. Carnitine is derived from lysine and methionine and is important for fatty acid transport into the mitochondrial matrix. [GO:0009437, https://en.wikipedia.org/wiki/Carnitine wikipedia, Reactome:R-HSA-200425]",,"The mitochondrial carnitine system catalyzes the transport of long-chain fatty acids into the mitochondrial matrix where they undergo beta oxidation. This transport system consists of the malonyl-CoA sensitive carnitine palmitoyltransferase I (CPT-I) localized in the mitochondrial outer membrane, the carnitine:acylcarnitine translocase, an integral inner membrane protein, and carnitine palmitoyltransferase II localized on the matrix side of the inner membrane. (Kerner & Hoppel, 2000; Ramsay et al. 2001). Additional reactions annotated here enable the uptake of carnitine and the regulation of fatty acid biosynthesis at the level of ACACA and ACACB to minimize simultaeous mitochondrial catabolism and cytosolic biosynthesis of long-chain fatty acids."
BMGC_PW0361,BMG_PW2411,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of phosphatidylinositol (PtdIns). Phosphorylation of PtdIns can occur at the 3, 4, and/or 5 position of the inositol ring using one or multiple phosphate groups. These phosphorylated forms of PtdIns are known as phosphoinositides. [GO:0046488, https://en.wikipedia.org/wiki/Phosphatidylinositol#Phosphoinositides wikipedia, Reactome:R-HSA-1483255]",,"Phosphatidylinositol (PI), a membrane phospholipid, can be reversibly phosphorylated at the 3, 4, and 5 positions of the inositol ring to generate seven phosphoinositides: phosphatidylinositol 3-phosphate (PI3P), phosphatidylinositol 4-phosphate (PI4P), phosphatidylinositol 5-phosphate (PI5P), phosphatidylinositol 3,4-bisphosphate PI(3,4)P2, phosphatidylinositol 4,5-bisphosphate PI(4,5)P2, phosphatidylinositol 3,5-bisphosphate PI(3,5)P2, and phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3). These seven phosphoinositides, which are heterogeneously distributed within cells, can serve as signature components of different intracellular compartment membranes and so help to mediate specificity of membrane interactions. Phosphoinositide levels are tightly regulated spatially and temporally by the action of various kinases and phosphatases whilst PI(4,5)P2 is also a substrate for phospholipase C. The differential localisation of each of these enzymes on specific compartment membranes ensures maintenance of the heterogeneous distribution of phosphoinositides despite the continuous membrane flow from one compartment to another. PI is primarily synthesised in the endoplasmic reticulum from where the phospholipid is exported to other compartments via membrane traffic or via cytosolic phospholipid transfer proteins. Phosphorylation of PI to PI4P primarily occurs in the Golgi, where PI4P plays an important role in the biogenesis of transport vesicles such as the secretory vesicle involved in its transport to the plasma membrane. At this place, PI4P has a major function acting as a precursor of PI(4,5)P2, which is located predominantly at this membrane. PI(4,5)P2 binds and regulates a wide range of proteins that function on the cell surface and serves as a precursor for second messengers. Additionally, it helps define this membrane as a target for secretory vesicles, functions as a coreceptor in endocytic processes, and functions as a cofactor for actin nucleation. At the plasma membrane, PI(4,5)P2 is further phosphorylated to PI(3,4,5)P3, another phosphoinositide with important signalling functions including stimulating cell survival and proliferation. The inositol 3-phosphatase, phosphatase and tensin homolog (PTEN) regenerates PI(4,5)P2, while the 5-phosphatases convert PI(3,4,5)P3 into the phosphoinositide, PI(3,4)P2, propagating the signal initiated by PI(3,4,5)P3. PI(3,4)P2 is further dephosphorylated in the endocytic pathway by inositol 4-phosphatases to PI3P, the signature phosphoinositide of the early endosomal compartment and a ligand for numerous endosomal proteins. However, the bulk of PI3P is generated directly in the endosomes by phosphorylation of PI. The subsequent endosomal phosphorylation of PI3P to PI(3,5)P2 is believed to generate docking sites for recruitment of cytosolic factors responsible for the control of outgoing traffic from the endosomes. The main localisation and function of the low abundance phosphoinositide PI5P, that can be generated by several pathways, remains to be determined (Krauss & Haucke 2007, Leventis & Grinstein 2010, Roth 2004, Gees et al. 2010, De Matteis & Godi 2004, van Meer et al. 2008, Vicinanza et al. 2008, Lemmon 2008, Kutaleladze 2010, Robinson & Dixon 2006, Blero et al. 2007, Liu & Bankaitis 2010, McCrea & De Camilli 2009, Vicinanza et al. 2008, Di Paolo & De Camilli, 2006)."
BMGC_PW0362,BMG_PW2417,"The cycle of synaptic vesicle exocytosis and neurotransmitter release and the subsequent endocytosis and recycling of synaptic vesicles at nerve terminals. [GO:0099504, KEGG:04721, PMID:15217342, PMID:25339369, Reactome:R-HSA-112310]","Communication between neurons is mediated by the release of neurotransmitter from synaptic vesicles (SVs). At the nerve terminal, SVs cycle through repetitive episodes of exocytosis and endocytosis. SVs are filled with neurotransmitters by active transport. The loaded SVs are then docked at a specialized region of the presynaptic plasma membrane known as the active zone, where they undergo a priming reaction. Upon arrival of an action potential, Ca2+ enters through voltage-gated channels and neurotransmitter is released by exocytosis, usually in less than a millisecond. After fusion, the vesicle is retrieved by endocytosis and reloaded for another round of exocytosis.","Neurotransmitter is stored in the synaptic vesicle in the pre-synaptic terminal prior to its release in the synaptic cleft upon depolarization of the pre-synaptic membrane. The release of the neurotransmitter is a multi-step process that is controlled by electrical signals passing through the axons in form of action potential. Neurotransmitters include glutamate, acetylcholine, nor-epinephrine, dopamine and seratonin. Each of the neurotransmitter cycle is independently described."
BMGC_PW0363,BMG_PW2635,"The series of molecular signals initiated by a ligand binding to pattern recognition receptor toll-like receptor 2, which is expressed constitutively on macrophages, dendritic cells, and B cells, and can be induced in some other cell types, including epithelial cells. [GO:0034134, Reactome:R-HSA-181438]",,"TLR2 is involved in recognition of peptidoglycan from gram-positive bacteria, bacterial lipoproteins, mycoplasma lipoprotein and mycobacterial products. It is quite possible that recognition of at least some other TLR2 ligands may be assisted by additional accessory proteins, particularly in association with TLR1 or TLR6. TLR2 is expressed constitutively on macrophages, dendritic cells, and B cells, and can be induced in some other cell types, including epithelial cells. TLR1 and TLR6, on the other hand, are expressed almost ubiquitously (Muzio et al. 2000). TLR2 may be a sensor and inductor of specific defense processes, including oxidative stress and cellular necrosis initially spurred by microbial compounds."
BMGC_PW0364,BMG_PW2636,"The series of molecular signals initiated by a ligand binding to the endolysosomal pattern recognition receptor toll-like receptor 3, expressed on myeloid dendritic cells, respiratory epithelium and macrophages. [GO:0034138, Reactome:R-HSA-168164]",,"Toll-like receptor 3 (TLR3) as was shown for mammals is expressed in various tissues and cells, including myeloid dendritic cells, macrophages, respiratory and intestinal epithelium, neurons and microglial cells to induce antiviral and inflammatory responses of the innate immunity in combating viral infections. TLR3 recognizes dsRNA in the endosome and that triggers the receptor dimerization. TLR3 recruits the adaptor TRIF (TICAM1), leading to the activation of NF-kappa-B and the production of type I interferons (IFNs). dsRNA-stimulated phosphorylation of two specific TLR3 tyrosine residues (Tyr759 and Tyr858) is essential for initiating TLR3 signaling pathways."
BMGC_PW0365,BMG_PW2637,"The series of molecular signals initiated by a ligand binding to pattern recognition receptor toll-like receptor 4, well known for its sensitivity to bacterial lipopolysaccharides. [GO:0034142, Reactome:R-HSA-166016]",,"166407	Toll-like Receptor 4 is a microbe associated molecular pattern receptor well known for it's sensitivity to bacterial lipopolysaccharides (LPS). LPS is assembled within diverse Gram-negative bacteria, many of which are human or plant pathogens. It is a component of the outer membrane of Gram-negative bacteria and consists of lipid A, a core polysaccharide and an O-polysaccharide of variable length (often more than 50 monosaccharide units). LPS is a potent activator of the innate immune response in humans, causing reactions including fever, headache, nausea, diarrhoea, changes in leukocyte and platelet counts, disseminated intravascular coagulation, multiorgan failure, shock and death. All these reactions are induced by cytokines and other endogenous mediators which are produced after interaction of LPS with the humoral and cellular targets of the host. In macrophages and dendritic cells, LPS-mediated activation of TLR4 triggers the biosynthesis of diverse mediators of inflammation, such as TNF-alpha and IL6, and activates the production of co-stimulatory molecules required for the adaptive immune response. In mononuclear and endothelial cells, LPS also stimulates tissue factor production. These events are desirable for clearing local infections, but when these various mediators and clotting factors are overproduced, they can damage small blood vessels and precipitate shock accompanied by disseminated intravascular coagulation and multiple organ failure.	Summation
169734	TLR4 is unique among the TLR family in its ability to recruit four adapters to activate two distinct signaling pathways. One pathway is activated by the pair of the adapters Mal or TIRAP (Toll/interleukin-1-receptor (TIR)-domain-containing adapter protein) and MyD88, which leads to the NFkB activation and the induction of pro-inflammatory cytokines. The second pathway is activated by the adapters TRIF (TIR-domain-containing adapter protein inducing interferon-beta) and TRAM (TRIF-related adapter molecule). The combined use of TRIF and TRAM adapters is specific for TLR4 signaling pathway and leads to the induction of type I interferons and delayed activation of NFkB. The previous model of TLR4 signaling pathway described the simultaneous activation of these two signaling pathways at the plasma membrane, however the later studies suggested that upon activation TLR4 first induces TIRAP-MyD88 signaling at the plasma membrane and is then endocytosed and activates TRAM-TRIF signaling from the early endosome [Kagan JC et al 2008; Tanimura N et al 2008; Zanoni I et al 2011].	Summation"
BMGC_PW0366,BMG_PW2638,"The series of molecular signals initiated by a ligand binding to pattern recognition receptor toll-like receptor 5, the receptor for flagellin, expressed on epithelial cells as well as on macrophages and dendritic cells. [GO:0034146, Reactome:R-HSA-168176]",,"TLR5 is the receptor for flagellin, the protein that forms bacterial flagella. Unlike most other Pathogen-Associated Molecular Patterns (PAMPs), flagellin does not undergo any posttranslational modifications that would distinguish it from cellular proteins. However, flagellin is extremely conserved at its amino- and carboxyl-termini, which presumably explains why it was selected as a ligand for innate immune recognition. TLR5 is expressed on epithelial cells as well as on macrophages and dendritic cells. Expression of TLR5 on intestinal epithelium is polarized such that TLR5 is expressed only on the basolateral side of the cell, as pathogenic but not commensal microbes cross the epithelial barrier. This ensures that innate immune responses are confined to pathogenic but not commensal microbes (Paul 2004; Hayashi et al. 2001; Gewirtz et al. 2001)."
BMGC_PW0367,BMG_PW2640,"The series of molecular signals initiated by a ligand binding to the endolysosomal pattern recognition receptor toll-like receptor 7, which senses ssRNA oligonucleotides from RNA viruses. [GO:0034154, Reactome:R-HSA-168181]",,"RNA can serve as a danger signal, both in its double-stranded form as well as single-stranded RNA (ssRNA). Toll like receptor 7 (TLR7) and TLR8 are endosomal receptors that sense ssRNA oligonucleotides containing guanosine (G)- and uridine (U)-rich sequences from RNA viruses (Jurk M et al. 2002; Heil F et al. 2004; Diebold SS et al. 2004; Li Y et al. 2013; reviewed in Lester SN & Li K 2014). TLR7 is primarily expressed in plasmacytoid dendritic cells (pDCs) and, to some extent, in B cells, monocytes and macrophages, whereas TLR8 is mostly expressed in monocytes, macrophages and myeloid DCs. Upon engagement of ssRNAs in endosomes, TLR7/8 initiate the myeloid differentiation factor 88 (MyD88)-dependent pathway, culminating in synthesis of type I and type III IFNs and proinflammatory mediators via activation of IFN regulatory factors (IRF7, IRF5) and NF-kappaB, respectively, depending on the cell type (Takaoka A et al., 2005; Heinz LX et al., 2020; reviewed in Lester SN & Li K 2014). TLR7 and TLR8 are able to detect GU-rich ssRNA sequences from the viral genomes of influenza, human immunodeficiency virus-1 (HIV-1), vesicular stomatitis virus (VSV), coxsackie B virus, coronavirus and flaviviruses (hepatitis C virus, HCV and West Nile virus, WNV; reviewed in Lester SN & Li K 2014). Specifically, GU-rich ssRNA oligonucleotides derived from HIV-1, for example, stimulate dendritic cells (DC) and macrophages to secrete interferon-alpha and proinflammatory, as well as regulatory, cytokines (Heil F et al. 2004). This has been found to be mediated by TLR7, as well as TLR8. Similarly, severe acute respiratory syndrome-associated coronavirus type 1 (SARS-CoV-1) GU-rich ssRNAs had powerful immunostimulatory activities in mononuclear phagocytes to induce considerable level of pro-inflammatory cytokine TNF-a, IL-6 and IL-12 release via the TLR7 and TLR8 (Li Y et al. 2013). Further, mice deficient in either Tlr7 or the TLR adaptor protein Myd88 demonstrated reduced responses to in vivo infection with VSV (Lund JM et al. 2004), mouse-adapted SARS-CoV-1 (Sheahan et al. 2008; Totura et al., 2015). Upon Middle East respiratory syndrome-related coronavirus (MERS-CoV) infection, lack of MyD88 signaling resulted in delayed viral clearance and increased lung pathology in mice (Zhao et al. 2014). Consistently, another study showed that Tlr7-/- mice have reduced IFN expression compared with wild-type mice (Channappanavar et al. 2019). In addition, loss of function TLR7 variants identified in the patients with SARS-CoV-2 (COVID-19) resulted in defective upregulation of type I IFN–related genes in the TLR7 pathway (Figure 3) in response to the TLR7 agonist imiquimod as compared with controls (Van der Made CI et al. 2020). Separate studies showed that synthetic imidazoquinoline compounds (e.g. imiquimod and R-848, low-molecular-weight immune response modifiers that can induce the synthesis of interferon-alpha) also exert their effects in a MyD88-dependent fashion through TLR7 or TLR8 (Hemmi H et al. 2002; Jurk M et al. 2002; Diebold SS et al. 2004). Some viruses utilize multiple strategies to evade antiviral innate immune signaling, as is seen with influenza or SARS coronaviruses. TLR7-mediated innate immunity, for example, was associated with the negative regulation through removing Lys63-linked polyubiquitin chains of TRAF3/TRAF6 by papin-like protease (PLpro) catalytic domain of nsp3 from SARS-CoV-1 (Li SW et al. 2016). Thus, TLR7 and TLR8 play a critical role in sensing of viral ssRNA in the endosome."
BMGC_PW0368,BMG_PW2641,"The series of molecular signals initiated by a ligand binding to the endolysosomal pattern recognition receptor toll-like receptor 8, which senses ssRNA oligonucleotides from RNA viruses. [GO:0034158, Reactome:R-HSA-168181]",,"RNA can serve as a danger signal, both in its double-stranded form as well as single-stranded RNA (ssRNA). Toll like receptor 7 (TLR7) and TLR8 are endosomal receptors that sense ssRNA oligonucleotides containing guanosine (G)- and uridine (U)-rich sequences from RNA viruses (Jurk M et al. 2002; Heil F et al. 2004; Diebold SS et al. 2004; Li Y et al. 2013; reviewed in Lester SN & Li K 2014). TLR7 is primarily expressed in plasmacytoid dendritic cells (pDCs) and, to some extent, in B cells, monocytes and macrophages, whereas TLR8 is mostly expressed in monocytes, macrophages and myeloid DCs. Upon engagement of ssRNAs in endosomes, TLR7/8 initiate the myeloid differentiation factor 88 (MyD88)-dependent pathway, culminating in synthesis of type I and type III IFNs and proinflammatory mediators via activation of IFN regulatory factors (IRF7, IRF5) and NF-kappaB, respectively, depending on the cell type (Takaoka A et al., 2005; Heinz LX et al., 2020; reviewed in Lester SN & Li K 2014). TLR7 and TLR8 are able to detect GU-rich ssRNA sequences from the viral genomes of influenza, human immunodeficiency virus-1 (HIV-1), vesicular stomatitis virus (VSV), coxsackie B virus, coronavirus and flaviviruses (hepatitis C virus, HCV and West Nile virus, WNV; reviewed in Lester SN & Li K 2014). Specifically, GU-rich ssRNA oligonucleotides derived from HIV-1, for example, stimulate dendritic cells (DC) and macrophages to secrete interferon-alpha and proinflammatory, as well as regulatory, cytokines (Heil F et al. 2004). This has been found to be mediated by TLR7, as well as TLR8. Similarly, severe acute respiratory syndrome-associated coronavirus type 1 (SARS-CoV-1) GU-rich ssRNAs had powerful immunostimulatory activities in mononuclear phagocytes to induce considerable level of pro-inflammatory cytokine TNF-a, IL-6 and IL-12 release via the TLR7 and TLR8 (Li Y et al. 2013). Further, mice deficient in either Tlr7 or the TLR adaptor protein Myd88 demonstrated reduced responses to in vivo infection with VSV (Lund JM et al. 2004), mouse-adapted SARS-CoV-1 (Sheahan et al. 2008; Totura et al., 2015). Upon Middle East respiratory syndrome-related coronavirus (MERS-CoV) infection, lack of MyD88 signaling resulted in delayed viral clearance and increased lung pathology in mice (Zhao et al. 2014). Consistently, another study showed that Tlr7-/- mice have reduced IFN expression compared with wild-type mice (Channappanavar et al. 2019). In addition, loss of function TLR7 variants identified in the patients with SARS-CoV-2 (COVID-19) resulted in defective upregulation of type I IFN–related genes in the TLR7 pathway (Figure 3) in response to the TLR7 agonist imiquimod as compared with controls (Van der Made CI et al. 2020). Separate studies showed that synthetic imidazoquinoline compounds (e.g. imiquimod and R-848, low-molecular-weight immune response modifiers that can induce the synthesis of interferon-alpha) also exert their effects in a MyD88-dependent fashion through TLR7 or TLR8 (Hemmi H et al. 2002; Jurk M et al. 2002; Diebold SS et al. 2004). Some viruses utilize multiple strategies to evade antiviral innate immune signaling, as is seen with influenza or SARS coronaviruses. TLR7-mediated innate immunity, for example, was associated with the negative regulation through removing Lys63-linked polyubiquitin chains of TRAF3/TRAF6 by papin-like protease (PLpro) catalytic domain of nsp3 from SARS-CoV-1 (Li SW et al. 2016). Thus, TLR7 and TLR8 play a critical role in sensing of viral ssRNA in the endosome."
BMGC_PW0369,BMG_PW2642,"The series of molecular signals initiated by a ligand binding to the endolysosomal pattern recognition receptor toll-like receptor 9, which recognizes unmethylated CpG DNA motifs of bacterial or viral origin. [GO:0034162, Reactome:R-HSA-168138]",,"CpG DNA is an unusual Pathogen-Associated Molecular Pattern (PAMP). Cytosine methylation exists in mammalian but not bacterial cells, and most (but not all) CpG in the mammalian genome is methylated. Therefore, unmethylated CpG DNA may signal the presence of microbial infection. Evidence of CpG recognition by TLR9 was demonstrated both in human and mouse, and this type of signaling requires its internalization into late endosomal/lysosomal compartments. TLR9 has been reported to be able to discern different types of CpG motifs, and therefore that it presumably recognizes CpG DNA directly. It appears that over evolutionary periods, TLR9 molecules expressed by different species have diverged. This has led to differences in the precise sequence motif (CpG dinucleotide plus flanking regions) that optimally stimulate the innate immune system of different animals."
BMGC_PW0370,BMG_PW2643,"The series of molecular signals initiated by a ligand such as a bacterial lipoprotein or peptide binding to a cotranslationally formed heterodimeric TLR1:TLR2 complex, followed by transmission of the signal by the activated receptor, and ending with the regulation of a downstream cellular process, e.g. transcription. [GO:0038123, Reactome:R-HSA-168179]",,"TLR1 is expressed by monocytes. TLR1 and TLR2 cotranslationally form heterodimeric complexes on the cell surface and in the cytosol. The TLR2:TLR1 complex recognizes Neisserial PorB and Mycobacterial triacylated lipoproteins and peptides, amongst others, triggering up-regulation of nuclear factor-kappaB production and apoptotic cascades. Such cooperation between TLR1 and TLR2 on the cell surface of normal human peripheral blood mononuclear cells, for instance, leads to the activation of pro-inflammatory cytokine secretion (Sandor et al. 2003)."
BMGC_PW0371,BMG_PW2644,"The series of molecular signals initiated by a ligand such as a bacterial cell wall component binding to a heterodimeric TLR6:TLR2 complex, followed by transmission of the signal by the activated receptor, and ending with the regulation of a downstream cellular process, e.g. transcription. [GO:0038124, Reactome:R-HSA-168188]",,"TLR2 and TLR4 recognize different bacterial cell wall components. While TLR4 is trained onto Gram-negative lipopolysaccharide components, TLR2 - in combination with TLR6 - plays a major role in recognizing peptidoglycan wall products from Gram-positive bacteria, as well as Mycobacterial diacylated lipopeptides. In particular, TLR6 appears to participate in discriminating the subtle differences between dipalmitoyl and tripalmitoyl cysteinyl residues (Okusawa et al. 2004)."
BMGC_PW0372,BMG_PW2645,"The series of molecular signals initiated by a ligand binding to pattern recognition receptor toll-like receptor 10, causing homodimerization. It is expressed as a highly N-glycosylated protein detectable in B cells and dendritic cells [GO:0034166, Reactome:R-HSA-168142]",,Little is known about TLR10 ligands. It has been established that the receptor homodimerizes upon binding and signals in an MyD88-dependent manner (Hasan U et al 2005; Nyman T et al 2008). It may also heterodimerize with TLRs 1 and 2. It is expressed in a restricted fashion as a highly N-glycosylated protein detectable in B cells and dendritic cells.
BMGC_PW0373,BMG_PW2646,"The chemical reactions and pathways involving the breakdown, interconversion and synthesis of amino acids containing sulfur, comprising cysteine, homocysteine, methionine and selenocysteine. Only plants and microorganisms employ all processes. [GO:0000096, Reactome:R-HSA-1614635]",,"The main sulfur amino acids are methionine, cysteine, homocysteine and taurine. Of these, the first two are proteinogenic. This group of reactions contains all processes that 1) break down sulfur amino acids, 2) interconvert between them, and 3) synthesize them from solved sulfide which comes from sulfate assimilation and reduction. Only plants and microorganisms employ all processes. Humans cannot de novo synthesize any sulfur amino acid, nor convert cysteine to methionine (Brosnan & Brosnan, 2006)."
BMGC_PW0374,BMG_PW2647,"Those metabolic reactions involved in oxidizing ethanol to acetaldehyde, which is oxidized to acetate. This is then condensed with coenzyme A to form acetyl-CoA. [GO:0006069, Reactome:R-HSA-71384]",,"Ethanol and related alcohols can be ingested as part of the diet and are formed by microorganisms in the intestinal tract. Ethanol oxidation to acetate occurs primarily in liver cells in a multistep process first described by Racker (1949). First, in the cytosol, ethanol is oxidized to acetaldehyde, with the formation of NADH. Second, in the mitochondrion, acetaldehyde is oxidized to acetate with the formation of NADH. Finally, acetate in the mitochondrion can be condensed with coenzyme A to form acetyl CoA. Polymorphisms in the enzymes catalyzing the first two steps are associated with variation in the efficiency of alcohol catabolism in human populations (Chen et al. 1999; Lange et al. 1976; Jornvall 1985). The molecular mechanism by which cytosolic acetaldehyde enters the mitochondrial matrix is not known (Lemasters 2007). Cytosolic enzymes capable of oxidizing acetaldehyde to acetate have also been identified and characterized in vitro (Inoue et al. 1979) so a purely cytosolic pathway for ethanol oxidation to acetate and conversion to acetyl-CoA can be annotated. The role of this pathway in vivo is unclear, though limited attempts to correlate deficiencies in the cytosolic enzyme with alcohol intolerance have yielded suggestive data (Yoshida et al. 1989). Additional peroxisomal and microsomal pathways for the oxidation of ethanol to acetaldehyde have been described; their physiological significance is unclear and they are not annotated here."
BMGC_PW0375,BMG_PW2648,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of glucose, also known as dextrose. It is an important source of energy for living organisms and is found free as well as combined in homo- and hetero-oligosaccharides and polysaccharides. [GO:0006006, Reactome:R-HSA-70326]",,"Glucose is the major form in which dietary sugars are made available to cells of the human body. Its breakdown is a major source of energy for all cells, and is essential for the brain and red blood cells. Glucose utilization begins with its uptake by cells and conversion to glucose 6-phosphate, which cannot traverse the cell membrane. Fates open to cytosolic glucose 6-phosphate include glycolysis to yield pyruvate, glycogen synthesis, and the pentose phosphate pathway. In some tissues, notably the liver and kidney, glucose 6-phosphate can be synthesized from pyruvate by the pathway of gluconeogenesis."
BMGC_PW0376,BMG_PW2649,"Those reactions involved in the biosynthesis of DNA. [GO:0071897, Reactome:R-HSA-69239]",,"The actual synthesis of DNA occurs in the S phase of the cell cycle. This includes the initiation of DNA replication, when the first nucleotide of the new strand is laid down during the synthesis of the primer. The DNA replication preinitiation events begin in late M or early G1 phase."
BMGC_PW0377,BMG_PW2650,"Those metabolic reactions involved in the degradation of fructose. [GO:0006001, Reactome:R-HSA-70350]",,"Fructose occurs naturally in foods as a free monosaccharide and as a component of the disaccharide sucrose. It is also widely used as a sweetener. In the body, fructose catabolism occurs in the liver and to a lesser extent in the kidney and small intestine. In these tissues, it is converted to dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate, two intermediates in the glycolytic pathway, in a sequence of three reactions. It is phosphorylated to form fructose 1-phosphate, which is cleaved by aldolase to yield dihydroxyacetone phosphate and D-glyceraldehyde, and the latter compound is phosphorylated to yield D-glyceraldehyde 3-phosphate. Other pathways exist for the conversion of D-glyceraldehyde to intermediates of glycolysis, but these appear to play only a minor role in normal fructose metabolism (Sillero et al. 1969)."
BMGC_PW0378,BMG_PW2651,"Those metabolic reactions involved in the degradation of galactose. [GO:0019388, Reactome:R-HSA-70370]",,"The main sources of galactose in the human diet are milk and milk products. The disaccharide lactose from these sources is hydrolyzed in the intestine to its constituent monosaccharides, glucose and galactose. Galactose is metabolized primarily in the liver in a sequence of three reactions that yield one molecule of glucose 1-phosphate per molecule of galactose. First, it is phosphorylated to yield galactose 1-phosphate. Then, galactose 1-phosphate and UDP-glucose react to form UDP-galactose and glucose 1-phosphate, and UDP-galactose undergoes epimerization to form UDP-glucose. In a reaction shared with other pathways, glucose 1-phosphate can be converted into glucose 6-phosphate (Holton et al. 2001; Elsas and Lai 2001)."
BMGC_PW0379,BMG_PW2653,"Those reactions involved in extending an existing DNA strand by activities including the addition of nucleotides to the 3' end of the strand. [GO:0022616, Reactome:R-HSA-69190]",,"Accurate and efficient genome duplication requires coordinated processes to replicate two template strands at eucaryotic replication forks. Knowledge of the fundamental reactions involved in replication fork progression is derived largely from biochemical studies of the replication of simian virus and from yeast genetic studies. Since duplex DNA forms an anti-parallel structure, and DNA polymerases are unidirectional, one of the new strands is synthesized continuously in the direction of fork movement. This strand is designated as the leading strand. The other strand grows in the direction away from fork movement, and is called the lagging strand. Several specific interactions among the various proteins involved in DNA replication underlie the mechanism of DNA synthesis, on both the leading and lagging strands, at a DNA replication fork. These interactions allow the replication enzymes to cooperate in the replication process (Hurwitz et al 1990; Brush et al 1996; Ayyagari et al 1995; Budd & Campbell 1997; Bambara et al 1997)."
BMGC_PW0380,BMG_PW2654,"The pathway in which DNA-dependent DNA replication is started; it begins when specific sequences, known as origins of replication, are recognized and bound by the origin recognition complex, followed by DNA unwinding. [GO:0006270, Reactome:R-HSA-68952]",,"DNA polymerases are not capable of de novo DNA synthesis and require synthesis of a primer, usually by a DNA-dependent RNA polymerase (primase) to begin DNA synthesis. In eukaryotic cells, the primer is synthesized by DNA polymerase alpha:primase. First, the DNA primase portion of this complex synthesizes approximately 6-10 nucleotides of RNA primer and then the DNA polymerase portion synthesizes an additional 20 nucleotides of DNA (Frick & Richardson 2002; Wang et al 1984)."
BMGC_PW0381,BMG_PW2655,"Those metabolic reactions involved in the degradation of glycerophospholipids. [GO:0046475, Reactome:R-HSA-6814848]",,"Reactions grouped in this pathway because of their shared chemistry - the hydrolysis of various phosphatidyl inositols and related phospholipids. They differ, however, in the tissues in which they occur and in their likely physiological roles. The activities of PNPLA6 and GDPD5 annotated here, for example, are especially prominent in kidney cells where the choline they generate plays a role in protecting cells from osmotic stress (Burg et al. 2007). Expression of others may be correlated with specific developmental events (Corda et al. 2013)."
BMGC_PW0382,BMG_PW2656,"Those metabolic reactions involved in the degradation of choline. [GO:0042426, Reactome:R-HSA-6798163]",,"Choline is an essential water-soluble nutrient in humans, serving as a precursor of phospholipids and the neurotransmitter acetylcholine. It is often associated with B vitamins based on its chemical structure but it isn't an official B vitamin. Its oxidation to betaine provides a link to folate-dependent, one-carbon metabolism where betaine is a methyl donor in the methionine cycle. Betaine is further metabolised to dimethylglycine which is cleared by the kidney (Ueland 2011, Hollenbeck 2012)."
BMGC_PW0383,BMG_PW2657,"A pathway of protein modification via removal of conjugated ubiquitin. [GO:0016579, Reactome:R-HSA-5688426]",,"Ubiquitination, the modification of proteins by the covalent attachment of ubiquitin (Ub), is a key regulatory mechanism for many many cellular processes, including protein degradation by the 26S proteasome. Ub conjugates linked via lysine 48 (K48) target substrates to the proteasome, whereas those linked via any of the six other Ub lysines can alter the function of the modified protein without leading to degradation. Deubiquitination, the reversal of this modification, regulates the function of ubiquitin-conjugated proteins. Deubiquitinating enzymes (DUBs) catalyze the removal of Ub and regulate Ub-mediated pathways. Given that Ub is covalently-linked to proteins destined to be degraded, it is a surprisingly long-lived protein in vivo (Haas & Bright 1987). This is due to the removal of Ub from its conjugates by DUBs prior to proteolysis. This may represent a quality control mechanism that prevents the degradation of proteins that were inappropriately tagged for degradation (Lam et al. 1997). DUBs are responsible for processing inactive Ub precursors and for keeping the 26S proteasome free of unanchored Ub chains that compete for Ub-binding sites. DUBs can be grouped into five families based on their conserved catalytic domains (Amerik & Hochstrasser 2004). Four of these families are thiol proteases and comprise the bulk of DUBs, while the fifth family is a small group of Ub specific metalloproteases. Thiol protease DUBs contain a Cys-His-Asp/Asn catalytic triad in which the Asp/Asn functions to polarize and orient the His, while the His serves as a general acid/base by both priming the catalytic Cys for nucleophilic attack on the (iso)peptide carbonyl carbon and by donating a proton to the lysine epsilon-amino leaving group. The nucleophilic attack of the catalytic Cys on the carbonyl carbon produces a negatively charged transition state that is stabilized by an oxyanion hole composed of hydrogen bond donors. A Cys-carbonyl acyl intermediate ensues and is then hydrolyzed by nucleophilic attack of a water molecule to liberate a protein C-terminal carboxylate and regenerate the enzyme. Ub binding often causes structural rearrangements necessary for catalysis. Many DUBs are inactivated by oxidation of the catalytic cysteine to sulphenic acid (single bond SOH) (Cotto-Rios et al. 2012, Lee et al. 2013). This can be reversed by reduction with DTT or glutathione. The sulphenic acid can be irreversibly oxidized to sulphinic acid (single bond SO2H) or sulphonic acid (single bond SO3H). Thiol proteases are reversibly inhibited by Ub C-terminal aldehyde, forming a thio-hemiacetal between the aldehyde group and the active site thiol."
BMGC_PW0384,BMG_PW2658,"Those metabolic reactions involving the fat-soluble vitamins. These include vitamins A, D, E and K. [GO:0006775, Reactome:R-HSA-6806667]",,"Vitamins A, D, E, and K are classified as fat-soluble. Metabolic pathways by which dietary precursors of vitamins A (Harrison 2005) and K (Shearer et al. 2012) are converted to active forms are annotated here. The conversion of 7-dehydrocholesterol is converted to active vitamin D (Dusso et al. 2005) is annotated as part of metabolism of steroids. (Vitamin E (tocopherol) is available in active form from the diet.)"
BMGC_PW0385,BMG_PW2659,"Those metabolic reactions involved in the synthesis, utilization and/or degradation of fructose. [GO:0006000, Reactome:R-HSA-5652084]",,"Fructose is found in fruits, is one of the components of the disaccharide sucrose, and is a widely used sweetener in processed foods. Dietary fructose is catabolized in the liver via fructose 1-phosphate to yield dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, which then are converted to pyruvate via steps of canonical glycolysis (Hers & Kusaka 1953; Sillero et al. 1969). Excessive dietary intake of fructose and its metabolism have been associated with major disease risks in humans, although this issue remains controversial (Kolderup & Svihus 2015; DiNicolantonio et al. 2015; Bray 2013; Mayes 1993; Rippe & Angelopoulos 2013; van Buul et al. 2013). Fructose can also be synthesized from glucose via the polyol pathway (Hers 1960; Oates 2008). This synthetic process provides the fructose found in seminal fluid and, in other tissues, can contribute to pathologies of diabetes."
BMGC_PW0386,BMG_PW2661,"The reactions involved in the biosynthesis of retinoic acid (RA). [GO:0002138, Reactome:R-HSA-5365859]",,"The major activated retinoid, all-trans-retinoic acid (atRA) is produced by the dehydrogenation of all-trans-retinol (atROL) by members of the short chain dehydrogenase/reductase (SDR) and aldehyde dehydrogenase (RALDH) gene families (Das et al. 2014, Napoli 2012)."
BMGC_PW0387,BMG_PW2663,"The chemical reactions and pathways involving hyaluronan, the naturally occurring anionic form of hyaluronic acid, which is not sulfated and is not found covalently attached to proteins as a proteoglycan. This includes any member of a group of glycosaminoglycans, the repeat units of which consist of beta-1,4 linked D-glucuronyl-beta-(1,3)-N-acetyl-D-glucosamine. [GO:0030212, Reactome:R-HSA-2142845]",,"Hyaluronan (hyaluronic acid, hyaluronate or HA) is an anionic glycosaminoglycan (GAG) distributed widely throughout connective, epithelial, and neural tissues and most abundant in the extracellular matrix and skin. HA is unique among the GAGs in that it is not sulfated and is not found covalently attached to proteins as a proteoglycan. HA polymers are very large (they can reach molecular weights of 10 million Da) and can displace a large volume of water making them excellent lubricators and shock absorbers. Another unique feature of HA is that it is synthesized at the plasma membrane unlike other GAGs which are formed in the Golgi. HA is a polymer of the disaccharide unit D-glucuronic acid and D-N-acetylglucosamine, linked via alternating beta-1,4 and beta-1,3 glycosidic bonds (Toole 2000, 2004, Volpi et al. 2009)."
BMGC_PW0388,BMG_PW2664,"A cellular senescence pathway associated with the dismantling of a cell as a response to oncogenic stress, such as the activation of the Ras oncogenic family, which can be caused by oncogenic mutations in RAS or RAF proteins, or by oncogenic mutations in growth factor receptors, such as EGFR, that act upstream of RAS/RAF/MAPK cascade. [GO:0090402, Reactome:R-HSA-2559585]",,"Oncogene-induced senescence (OIS) is triggered by high level of RAS/RAF/MAPK signaling that can be caused, for example, by oncogenic mutations in RAS or RAF proteins, or by oncogenic mutations in growth factor receptors, such as EGFR, that act upstream of RAS/RAF/MAPK cascade. Oncogene-induced senescence can also be triggered by high transcriptional activity of E2F1, E2F2 or E2F3 which can be caused, for example, by the loss-of-function of RB1 tumor suppressor. Oncogenic signals trigger transcription of CDKN2A locus tumor suppressor genes: p16INK4A and p14ARF. p16INK4A and p14ARF share exons 2 and 3, but are expressed from different promoters and use different reading frames (Quelle et al. 1995). Therefore, while their mRNAs are homologous and are both translationally inhibited by miR-24 microRNA (Lal et al. 2008, To et al. 2012), they share no similarity at the amino acid sequence level and perform distinct functions in the cell. p16INK4A acts as the inhibitor of cyclin-dependent kinases CDK4 and CDK6 which phosphorylate and inhibit RB1 protein thereby promoting G1 to S transition and cell cycle progression (Serrano et al. 1993). Increased p16INK4A level leads to hypophosphorylation of RB1, allowing RB1 to inhibit transcription of E2F1, E2F2 and E2F3-target genes that are needed for cell cycle progression, which results in cell cycle arrest in G1 phase. p14-ARF binds and destabilizes MDM2 ubiquitin ligase (Zhang et al. 1998), responsible for ubiquitination and degradation of TP53 (p53) tumor suppressor protein (Wu et al. 1993, Fuchs et al. 1998, Fang et al. 2000). Therefore, increased p14-ARF level leads to increased level of TP53 and increased expression of TP53 target genes, such as p21, which triggers p53-mediated cell cycle arrest and, depending on other factors, may also lead to p53-mediated apoptosis. CDKN2B locus, which encodes an inhibitor of CDK4 and CDK6, p15INK4B, is located in the vicinity of CDKN2A locus, at the chromosome band 9p21. p15INK4B, together with p16INK4A, contributes to senescence of human T-lymphocytes (Erickson et al. 1998) and mouse fibroblasts (Malumbres et al. 2000). SMAD3, activated by TGF-beta-1 signaling, controls senescence in the mouse multistage carcinogenesis model through regulation of MYC and p15INK4B gene expression (Vijayachandra et al. 2003). TGF-beta-induced p15INK4B expression is also important for the senescence of hepatocellular carcinoma cell lines (Senturk et al. 2010). MAP kinases MAPK1 (ERK2) and MAPK3 (ERK1), which are activated by RAS signaling, phosphorylate ETS1 and ETS2 transcription factors in the nucleus (Yang et al. 1996, Seidel et al. 2002, Foulds et al. 2004, Nelson et al. 2010). Phosphorylated ETS1 and ETS2 are able to bind RAS response elements (RREs) in the CDKN2A locus and stimulate p16INK4A transcription (Ohtani et al. 2004). At the same time, activated ERKs (MAPK1 i.e. ERK2 and MAPK3 i.e. ERK1) phosphorylate ERF, the repressor of ETS2 transcription, which leads to translocation of ERF to the cytosol and increased transcription of ETS2 (Sgouras et al. 1995, Le Gallic et al. 2004). ETS2 can be sequestered and inhibited by binding to ID1, resulting in inhibition of p16INK4A transcription (Ohtani et al. 2004). Transcription of p14ARF is stimulated by binding of E2F transcription factors (E2F1, E2F2 or E2F3) in complex with SP1 to p14ARF promoter (Parisi et al. 2002). Oncogenic RAS signaling affects mitochondrial metabolism through an unknown mechanism, leading to increased generation of reactive oxygen species (ROS), which triggers oxidative stress induced senescence pathway. In addition, increased rate of cell division that is one of the consequences of oncogenic signaling, leads to telomere shortening which acts as another senescence trigger. While OIS has been studied to considerable detail in cultured cells, establishment of in vivo role of OIS has been difficult due to lack of specific biomarkers and its interconnectedness with other senescence pathways (Baek and Ryeom 2017, reviewed in Sharpless and Sherr 2015)."
BMGC_PW0389,BMG_PW2665,"Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a heat stimulus, a temperature stimulus above the optimal temperature for that organism. In response to exposure to elevated temperature, cells activate a number of cytoprotective mechanisms known collectively as the \heat shock response\. [GO:0034605, Reactome:R-HSA-3371556]",,"In response to exposure to elevated temperature and certain other proteotoxic stimuli (e.g., hypoxia, free radicals) cells activate a number of cytoprotective mechanisms known collectively as ""heat shock response"". Major aspects of the heat shock response (HSR) are evolutionarily conserved events that allow cells to recover from protein damage induced by stress (Liu XD et al. 1997; Voellmy R & Boellmann F 2007; Shamovsky I & Nudler E 2008; Anckar J & Sistonen L 2011). The main hallmark of HSR is the dramatic alteration of the gene expression pattern. A diverse group of protein genes is induced by the exposure to temperatures 3-5 degrees higher than physiological. Functionally, most of these genes are molecular chaperones that ensure proper protein folding and quality control to maintain cell proteostasis. At the same time, heat shock-induced phosphorylation of translation initiation factor eIF2alpha leads to the shutdown of the nascent polypeptide synthesis reducing the burden on the chaperone system that has to deal with the increased amount of misfolded and thermally denatured proteins (Duncan RF & Hershey JWB 1989; Sarkar A et al. 2002; Spriggs KA et al. 2010). The induction of HS gene expression primarily occurs at the level of transcription and is mediated by heat shock transcription factor HSF1(Sarge KD et al. 1993; Baler R et al. 1993). Human cells express five members of HSF protein family: HSF1, HSF2, HSF4, HSFX and HSFY. HSF1 is the master regulator of the heat inducible gene expression (Zuo J et al. 1995; Akerfelt M et al. 2010). HSF2 is activated in response to certain developmental stimuli in addition to being co-activated with HSF1 to provide promoter-specific fine-tuning of the HS response by forming heterotrimers with HSF1 (Ostling P et al. 2007; Sandqvist A et al. 2009). HSF4 lacks the transcription activation domain and acts as a repressor of certain genes during HS (Nakai A et al. 1997; Tanabe M et al. 1999; Kim SA et al. 2012). Two additional family members HSFX and HSFY, which are located on the X and Y chromosomes respectively, remain to be characterized (Bhowmick BK et al. 2006; Shinka T et al. 2004; Kichine E et al. 2012). Under normal conditions HSF1 is present in both cytoplasm and nucleus in the form of an inactive monomer. The monomeric state of HSF1 is maintained by an intricate network of protein-protein interactions that include the association with HSP90 multichaperone complex, HSP70/HSP40 chaperone machinery, as well as intramolecular interaction of two conserved hydrophobic repeat regions. Monomeric HSF1 is constitutively phosphorylated on Ser303 and Ser 307 by (Zou J et al. 1998; Knauf U et al. 1996; Kline MP & Moromoto RI 1997; Guettouche T et al. 2005). This phosphorylation plays an essential role in ensuring cytoplasmic localization of at least a subpopulation of HSF1 molecules under normal conditions (Wang X et al. 2004). Exposure to heat and other proteotoxic stimuli results in the release of HSF1 from the inhibitory complex with chaperones and its subsequent trimerization, which is promoted by its interaction with translation elongation factor eEF1A1 (Baler R et al. 1993; Shamovsky I et al. 2006; Herbomel G et al 2013). The trimerization is believed to involve intermolecular interaction between hydrophobic repeats 1-3 leading to the formation of a triple coil structure. Additional stabilization of the HSF1 trimer is provided by the formation of intermolecular S-S bonds between Cys residues in the DNA binding domain (Lu M et al.2008). Trimeric HSF1 is predominantly localized in the nucleus where it binds the specific sequence in the promoter of hsp genes (Sarge KD et al. 1993; Wang Y and Morgan WD 1994). The binding sequence for HSF1 (HSE, heat shock element) contains series of inverted repeats nGAAn in head-to-tail orientation, with at least three elements being required for the high affinity binding. Binding of the HSF1 trimer to the promoter is not sufficient to induce transcription of the gene (Cotto J et al. 1996). In order to do so, HSF1 needs to undergo inducible phosphorylation on specific Ser residues such as Ser230, Ser326. This phosphorylated form of HSF1 trimer is capable of increasing the promoter initiation rate. HSF1 bound to DNA promotes recruiting components of the transcription mediator complex and relieving promoter-proximal pause of RNA polymerase II through its interaction with TFIIH transcription factor (Yuan CX & Gurley WB 2000). HSF1 activation is regulated in a precise and tight manner at multiple levels (Zuo J et al. 1995; Cotto J et al. 1996). This allows fast and robust activation of HS response to minimize proteotoxic effects of the stress. The exact set of HSF1 inducible genes is probably cell type specific. Moreover, cells in different pathophysiological states will display different but overlapping profile of HS inducible genes."
BMGC_PW0390,BMG_PW2666,"The series of events underlying mitotic metaphase, the cell cycle phase following prophase or prometaphase, during which chromosomes become aligned via spindle fibers on the equatorial or metaphase plate of the cell. Such an organization helps to ensure that later, when the chromosomes are separated, each new nucleus that is formed receives one copy of each chromosome.  [GO:0000089, Reactome:R-HSA-2555396]",,"Metaphase is marked by the formation of the metaphase plate. The metaphase plate is formed when the spindle fibers align the chromosomes along the middle of the cell. Such an organization helps to ensure that later, when the chromosomes are separated, each new nucleus that is formed receives one copy of each chromosome. This pathway has not yet been annotated in Reactome. The metaphase to anaphase transition during mitosis is triggered by the destruction of mitotic cyclins. In anaphase, the paired chromosomes separate at the centromeres, and move to the opposite sides of the cell. The movement of the chromosomes is facilitated by a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules."
BMGC_PW0391,BMG_PW2667,"The series of events underlying mitotic anaphase, following metaphase, during which the chromosomes separate and migrate towards the poles of the spindle at the opposite sides of the cell. The movement of the chromosomes is facilitated by a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules. [GO:0000090, Reactome:R-HSA-68882]",,"In anaphase, the paired chromosomes separate at the centromeres, and move to the opposite sides of the cell. The movement of the chromosomes is facilitated by a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules."
BMGC_PW0392,BMG_PW2668,A cobalamin (Cbl) metabolic pathway that deviates from what its normal course should be. Cbl deficiency results in hyperhomocysteinemia (due to defects in the conversion of homocysteine to methionine which requires Cbl as a cofactor) and increased levels of methylmalonic acid. Symptoms of Cbl deficiency are bone marrow promegaloblastosis (megaloblastic anemia) due to the inhibition of DNA synthesis (specifically purines and thymidine) and neurological symptoms. [Reactome:R-HSA-3296469],,
BMGC_PW0393,BMG_PW2669,A biotin metabolic pathway that deviates from what its normal course should be. [Reactome:R-HSA-3323169],,"Biotin (Btn, vitamin B7, vitamin H, coenzyme R) is an essential cofactor for five biotin-dependent carboxylase enzymes, involved in the synthesis of fatty acids, isoleucine, valine and in gluconeogenesis. Thus, Btn is necessary for cell growth, fatty acid synthesis and the metabolism of fats and amino acids. Inherited metabolic disorders characterized by deficient activities of all five biotin dependent carboxylases are termed multiple carboxylase deficiencies. Two congenital defects in biotin metabolism leading to multiple carboxylase deficiency are known, holocarboxylase synthetase deficiency (MIM 609018) and biotinidase deficiency (MIM 253260). In both scenarios symptoms include ketolactic acidosis, organic aciduria, hyperammonemia, skin rashes, hypotonia, seizures, developmental delay, alopecia, and coma. As humans are auxotrophic for Btn, the micronutrient must be obtained from external soures such as intestinal microflora and dietary forms. Accordingly, severe malnutrition can also give rise to biotin deficiency and multiple carboxylase deficiency. Biotin deficiency can also be induced by the excessive consumption of raw egg white that contains the biotin-binding protein avidin. Holocarboxylase synthetase deficiency arises when all five biotin-dependent enzymes are not biotinylated leading to their reduced activities. The defective genes causing these conditions are described here (Pendini et al. 2008, Suzuki et al. 2005). Biotinidase deficiency is caused by defects in the recycling of Btn. General symptoms include decreased appetite and growth, dermatitis and perosis. The defective genes causing these conditions are described here (Procter et al. 2013)."
BMGC_PW0394,BMG_PW2674,"Fatty acid degradation via beta oxidation, acting on very long-chain fatty acids having an aliphatic tail containing more than 22 carbons. [GO:0140493, Reactome:R-HSA-390247]",,Linear fatty acids containing more than 18 carbons are broken down by beta-oxidation in peroxisomes to yield acetyl-CoA and medium chain-length fatty acyl CoA's such as octanoyl-CoA (Wanders and Waterham 2006).
BMGC_PW0395,BMG_PW2675,"A pathway in which force is generated within muscle tissue, resulting in a change in muscle geometry. Force generation involves a calcium-triggered chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. [GO:0006936, Reactome:R-HSA-397014]",,"In this module, the processes by which calcium binding triggers actin - myosin interactions and force generation in smooth and striated muscle tissues are annotated."
BMGC_PW0396,BMG_PW2676,"A pathway in which force is generated within striated muscle tissue, resulting in a change in muscle geometry. Force generation involves a calcium-triggered chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. Striated muscle contains repeating units (sarcomeres) of the contractile myofibrils that are arranged in registry throughout the cell, resulting in transverse or oblique striations observable by light microscope. [GO:0006941, Reactome:R-HSA-390522]",,"Striated muscle contraction is a process whereby force is generated within striated muscle tissue, resulting in a change in muscle geometry, or in short, increased force being exerted on the tendons. Force generation involves a chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. Striated muscle is a type of muscle composed of myofibrils, containing repeating units called sarcomeres, in which the contractile myofibrils are arranged in parallel to the axis of the cell, resulting in transverse or oblique striations observable at the level of the light microscope. Here striated muscle contraction is represented on the basis of calcium binding to the troponin complex, which exposes the active sites of actin. Once the active sites of actin are exposed, the myosin complex bound to ADP can bind actin and the myosin head can pivot, pulling the thin actin and thick myosin filaments past one another. Once the myosin head pivots, ADP is ejected, a fresh ATP can be bound and the energy from the hydrolysis of ATP to ADP is channeled into kinetic energy by resetting the myosin head. With repeated rounds of this cycle the sarcomere containing the thin and thick filaments effectively shortens, forming the basis of muscle contraction."
BMGC_PW0397,BMG_PW2677,"A pathway in which force is generated within smooth muscle tissue, resulting in a change in muscle geometry. Force generation involves a calcium-triggered chemo-mechanical energy conversion step that is carried out by the actin/myosin complex activity, which generates force through ATP hydrolysis. Smooth muscle differs from striated muscle in the much higher actin/myosin ratio, the absence of conspicuous sarcomeres and the ability to contract to a much smaller fraction of its resting length. [GO:0006939, Reactome:R-HSA-445355]",,"Layers of smooth muscle cells can be found in the walls of numerous organs and tissues within the body. Smooth muscle tissue lacks the striated banding pattern characteristic of skeletal and cardiac muscle. Smooth muscle is triggered to contract by the autonomic nervous system, hormones, autocrine/paracrine agents, local chemical signals, and changes in load or length. Actin:myosin cross bridging is used to develop force with the influx of calcium ions (Ca2+) initiating contraction. Two separate protein pathways, both triggered by calcium influx contribute to contraction, a calmodulin driven kinase pathway, and a caldesmon driven pathway. Recent evidence suggests that actin, myosin, and intermediate filaments may be far more volatile then previously suspected, and that changes in these cytoskeletal elements along with alterations of the focal adhesions that anchor these proteins may contribute to the contractile cycle. Contraction in smooth muscle generally uses a variant of the same sliding filament model found in striated muscle, except in smooth muscle the actin and myosin filaments are anchored to focal adhesions, and dense bodies, spread over the surface of the smooth muscle cell. When actin and myosin move across one another focal adhesions are drawn towards dense bodies, effectively squeezing the cell into a smaller conformation. The sliding is triggered by calcium:caldesmon binding, caldesmon acting in an analogous fashion to troponin in striated muscle. Phosphorylation of myosin light chains also is involved in the initiation of an effective contraction."
BMGC_PW0398,BMG_PW2678,,,"PKB and PDK1 are activated via membrane-bound PIP3. Activated PDK1 phosphorylates PKB, which in turn phosphorylates PDE3B. The latter hydrolyses cAMP to 5'AMP, depleting cAMP pools."
BMGC_PW0399,BMG_PW2679,,,Mitogen-activated protein kinase kinase MAP2K1 (also known as MEK1) is a dual threonine and tyrosine recognition kinase that phosphorylates and activates MAPK3 (ERK1) (Ohren et al. 2004; Roskoski 2012a).
BMGC_PW0400,BMG_PW2680,,,
BMGC_PW0401,BMG_PW2681,,,"Ubiquitous environmental and endogenous genotoxic agents cause DNA lesions that can interfere with normal DNA metabolism including DNA replication, eventually resulting in mutations that lead to carcinogenesis and/or cell death. Cells possess repair mechanisms like nucleotide excision and base excision repair pathways to maintain the integrity of the genome. However, some types of lesions are repaired very inefficiently and others may not be recognized and repaired before the lesion-containing DNA undergoes DNA replication. To prevent acute cell death through arrested DNA replication at unrepaired lesions, cells have a mechanism, referred to as translesion synthesis (TLS), which allows DNA synthesis to proceed past lesions. TLS depends on the Y family of DNA polymerases (Lindahl and Wood 1999, Masutani et al. 2000, Yang 2014)."
BMGC_PW0402,BMG_PW2682,,,"Damaged double strand DNA (dsDNA) cannot be successfully used as a template by replicative DNA polymerase delta (POLD) and epsilon (POLE) complexes (Hoege et al. 2002). When the replication complex composed of PCNA, RPA, RFC and POLD or POLE stalls at a DNA damage site, PCNA becomes monoubiquitinated by RAD18 bound to UBE2B (RAD6). POLD or POLE dissociate from monoubiquitinated PCNA, while Y family DNA polymerases - REV1, POLH (DNA polymerase eta), POLK (DNA polymerase kappa) and POLI (DNA polymerase iota) - bind monoubiquitinated PCNA through their ubiquitin binding and PCNA binding motifs, resulting in a polymerase switch and initiation of translesion synthesis (TLS) (Hoege et al. 2002, Friedberg et al. 2005)."
BMGC_PW0403,BMG_PW2683,,,"DNA polymerase eta (POLH) consists of 713 amino acids and can bypass thymidine-thymidine dimers, correctly adding two dAMPs opposite to the lesion. Mutations in the POLH gene result in the loss of this bypass activity and account for the XP variant phenotype (XPV) in human xeroderma pigmentosum disorder patients. POLH can carry out TLS past various UV and chemically induced lesions via two steps: (a) preferential incorporation of correct bases opposite to the lesion (b) conditional elongation only at the sites where such correct bases are inserted (Masutani et al. 1999, Masutani et al. 2000)."
BMGC_PW0404,BMG_PW2684,,,Base excision repair is initiated by a DNA glycosylase which first recognizes and removes a damaged or incorrect (e.g. mismatched) base (Sokhansanj et al. 2002).
BMGC_PW0405,BMG_PW2685,,,Damaged pyrimidines are cleaved by pyrimide-specific glycosylases (Lindahl and Wood 1999).
BMGC_PW0406,BMG_PW2686,,,"The recognition and removal of an altered base by a DNA glycosylase is thought to involve the diffusion of the enzyme along the minor grove of the DNA molecule. The enzyme presumably compresses the backbone of the affected DNA strand at the site of damage. This compression is thought to result in an outward rotation of the damaged residue into a ""pocket"" of the enzyme that recognizes and cleaves the altered base from the backbone (Slupphaug et al. 1996, Parikh et al. 1998)."
BMGC_PW0407,BMG_PW2687,,,"Damaged purines are cleaved from the sugar-phosphate backbone by purine-specific glycosylases (Saparbaev and Laval 1994, Lindahl and Wood 1999)."
BMGC_PW0408,BMG_PW2688,,,"Following cleavage of the damaged base, DNA glycosylase is displaced by APEX1, an AP endonuclease (Parikh et al. 1998)."
BMGC_PW0409,BMG_PW2689,,,"During POLB-dependent long patch base excision repair (BER), PARP1 and/or PARP2 is recruited to the BER site along with flap endonuclease FEN1. PARP1 and/or PARP2 and FEN1 facilitate POLB-mediated strand displacement synthesis which involves incorporation of 2-10 nucleotides at the 3' end of the APEX1-created single strand break (SSB). After the DNA strand displacement synthesis is completed and the displaced strand is cleaved, POLB recruits DNA ligase I (LIG1) to ligate the SSB (Klungland and Lindahl 1997, Dimitriadis et al. 1998, Prasad et al. 2001, Lavrik et al. 2001, Tomkinson et al. 2001, Ranalli et al. 2002, Cistulli et al. 2004, Liu et al. 2005)."
BMGC_PW0410,BMG_PW2690,,,"While the single nucleotide replacement pathway appears to facilitate the repair of most damaged bases, an alternative BER pathway is evoked when the structure of the 5'-terminal sugar phosphate is such that it cannot be cleaved through the AP lyase activity of DNA polymerase beta (POLB). Under these circumstances, a short stretch of residues containing the abasic site is excised and replaced (Dianov et al., 1999). Following DNA glycosylase-mediated cleavage of the damaged base, the endonuclease APEX1 is recruited to the site of damage where it cleaves the 5' side of the abasic deoxyribose residue, as in the single nucleotide replacement pathway. However, POLB then synthesizes the first replacement residue without prior cleavage of the 5'-terminal sugar phosphate, hence displacing this entity. Long-patch BER can be completed by continued POLB-mediated DNA strand displacement synthesis in the presence of PARP1 or PARP2, FEN1 and DNA ligase I (LIG1) (Prasad et al. 2001). When the PCNA-containing replication complex is available, as is the case with cells in the S-phase of the cell cycle, DNA strand displacement synthesis is catalyzed by DNA polymerase delta (POLD) or DNA polymerase epsilon (POLE) complexes, in the presence of PCNA, RPA, RFC, APEX1, FEN1 and LIG1 (Klungland and Lindahl 1997, Dianova et al. 2001). In both POLB-dependent and PCNA-dependent DNA displacement synthesis, the displaced DNA strand containing the abasic sugar phosphate creates a flap structure that is recognized and cleaved by the flap endonuclease FEN1. The replacement residues added by POLB or POLD/POLE are then ligated by the DNA ligase I (LIG1) (Klungland and Lindahl, 1997; Matsumoto et al., 1999)."
BMGC_PW0411,BMG_PW2691,,,"The single nucleotide replacement pathway of base excision repair appears to facilitate the repair of most damaged bases. Following DNA glycosylase mediated cleavage of the damaged base, the endonuclease APEX1 is recruited to the site of damage where it cleaves the 5' side of the abasic (AP) deoxyribose residue. DNA polymerase beta (POLB) then cleaves the 3' side of the AP sugar phosphate, thus excising the AP residue. APEX1 is subsequently released, the XRCC1:LIG3 complex is recruited, and POLB mediates the synthesis of the replacement residue. Following LIG3 mediated ligation of the replaced residue, the XRCC1:LIG3 complex dissociates from DNA (Lindahl and Wood, 1999). An alternative BER pathway is employed when the structure of the terminal sugar phosphate is such that it cannot be cleaved by the AP lyase activity of POLB."
BMGC_PW0412,BMG_PW2692,,,This class of mRNAs is expressed from genes that lack introns yet the transcripts end in polyA tails. These tails are formed by a mechanism similar to that for pre-mRNAs containing introns. It is believed that there is a cis-element that replaces the 3' splice site that normally serves to activate polyadenylation of intron containing pre-mRNAs.
BMGC_PW0413,BMG_PW2693,,,"BIM acts as a sentinel to check the integrity of the cytoskeleton. It exists as two variant proteins: BIM-EL and BIM-L. In healthy cells, these two isoforms are sequestered to the dynein motor complex on microtubules via the dynein light chain DLC1. JNK or MAPK8 releases BIM in response to UV irradiation by phosphorylation."
BMGC_PW0414,BMG_PW2694,,,The switching on/off of its phosphorylation by growth/survival factors regulates BAD activity. BAD remains sequestered by 14-3-3 scaffold proteins after phosphorylation by Akt1. Calcineurin activates BAD by dephosphorylation.
BMGC_PW0415,BMG_PW2695,,,NOXA is transactivated in a p53-dependent manner and by E2F1. Activated NOXA is translocated to mitochondria.
BMGC_PW0416,BMG_PW2696,,,tBID binds to its mitochondrial partner BAK to release cytochrome c. Activated tBID results in an allosteric activation of BAK. This may induce its intramembranous oligomerization into a pore for cytochrome c efflux.
BMGC_PW0417,BMG_PW2697,,,"Bcl-2 interacts with tBid (Yi et al. 2003), BIM (Puthalakath et al. 1999), PUMA (Nakano and Vousden 2001), NOXA (Oda et al. 2000), BAD (Yang et al. 2005), BMF (Puthalakath et al. 2001), resulting in inactivation of BCL2. Binding of BCL2 to tBID inhibits BID-induced cytochrome C release and apoptosis (Yi et al. 2003). BH3 only proteins associate with and inactivate anti-apoptotic BCL-XL."
BMGC_PW0418,BMG_PW2699,,,"The apoptosome is a cytoplasmic protein complex of two major components ‑ the adapter protein apoptotic protease activating factor 1 (APAF1) and the protease caspase‑9 (CASP9) which interact with each other through their caspase recruitment domains (CARD) (Qin et al. 1999; Yuan S et al. 2010; Yuan S & Akey CW 2013). The function of the apoptosome is to assemble a multimeric complex between APAF1 and procaspase-9 CARDs to facilitate CASP9 activation (Jiang X and Wang X 2000; Srinivasrula SM et al. 2001; Shiozaki EN et al. 2002). The apoptosome is assembled upon APAF1 interaction with cytochrome c (CYCS), which is released from the mitochondrial intermembrane space during apoptosis (Zou H et al. 1997; Yuan S et al. 2013; Shakeri R et al. 2017). CYCS‑bound APAF1 undergoes ATP-mediated conformational changes and in the presence of CARD of CASP9 oligomerizes into a heptameric complex, which activates procaspase 9 (Zou H et al. 1997; Bratton SB et al. 2010; Acehan D et al. 2002; Yu X et al. 2005; Yuan S et al. 2010; Su TW et al. 2017). In the apoptosome, recruitment of caspase-9 may occur before oligomerization in the CARD disk, which presumably brings the caspase domain into proximity for their dimerization and activation (Su TW et al. 2017; Hu Q et al. 2014; Cheng TC et al. 2016). Once activated, CASP9 activates downstream effector caspases‑3 and ‑7. The activated effector caspases then cleave various cellular proteins. Different models have been proposed to explain CASP9 activation: the “proximity‑driven dimerization model” and the “induced conformation model”. The first models states that upon binding to heptameric APAF1, monomers of procaspase‑9 are brought into close proximity at a high concentration (Acehan et al. 2002; Renatus et al. 2001). This induces dimerization which is sufficient for CASP9 activation whereas autoprocessing within the apoptosome complex merely stabilizes CASP9 dimer (Boatright KM et al. 2003; Pop C et al. 2006). The “induced conformation model” is based on the observation that CASP9 has a much higher level of catalytic activity when it's bound to the apoptosome. The model suggests that a conformational change occurs at the active site of CASP9 upon binding to APAF1 thus inducing CASP9 homodimerization and stabilizing it in the catalytically active conformation (Shiozaki EN et al. 2002). CASP9 activation may also involve formation of a multimeric CARD:CARD assembly between APAF1 and procaspase‑9 (Hu Q et al. 2014)."
BMGC_PW0419,BMG_PW2700,,,Procaspase-3 and 7 are cleaved by the apoptosome.
BMGC_PW0420,BMG_PW2701,,,"Upon its release from the mitochondrial intermembrane space, cytochrome c (CYSC) binds to and causes an ATP-mediated conformational change in the cytoplasmic adaptor protein apoptotic protease‑activating factor 1 (APAF1). This conformational change triggers the formation of procaspase-9-activating oligomeric protein complex named apoptosome. The active caspase‑9 holoenzyme activates downstream effector caspases‑3 and ‑7. The activated effector caspases then cleave various cellular proteins."
BMGC_PW0421,BMG_PW2702,,,"Second mitochondria‑derived activator of caspases protein (SMAC, also known as direct IAP binding protein with low pI or DIABLO) in its dimeric form interacts and antagonizes X‑linked inhibitor of apoptosis protein (XIAP) by concurrently targeting both BIR2 and BIR3 domains of XIAP (Chai J et al. 2000; Liu Z et sl. 2000; Burke SP & Smith JB 2010). XIAP inhibits apoptosis by binding to and inhibiting the effectors caspase‑3 and ‑7 and an initiator caspase‑9 (Deveraux QL et al. 1997; Paulsen M et al. 2008). During apoptosis, SMAC (DIABLO) is released from the mitochondria (Du C et al. 2000). In the cytosol, SMAC binds to XIAP displacing it from caspase:XIAP complexes liberating the active caspases (Wu G et al. 2000; Abhari BA & Davoodi J 2008)."
BMGC_PW0422,BMG_PW2703,,,"Second mitochondria derived activator of caspase/direct inhibitor of apoptosis binding protein with low pI (SMAC, also known as DIABLO) regulates XIAP function and potentiates caspase-3, -7 and -9 activity by disrupting the interaction of caspases with XIAP. Residues 56-59 of SMAC (DIABLO) are homologous to the amino-terminal motif that is used by caspase-9 (CASP9) to bind to the BIR3 domain of XIAP. SMAC (DIABLO) competes with CASP9 for binding to BIR3 domain of XIAP promoting the release of XIAP from the CASP9:apoptosome complex (Srinivasula SM et al. 2001; Salvesen et al. 2002). The binding of SMAC to the BIR2 and BIR3 regions of XIAP creates a steric hindrance that is essential for preventing binding of XIAP linker region with effector caspases CASP3 and CASP7 thus achieving neutralization of XIAP inhibition. The strong affinity for XIAP allows SMAC (DIABLO) to displace caspase-3, -7 from the XIAP:caspase complexes (Wu G et al. 2000; Chai J et al. 2001; Huang Y et al. 2003; Abhari BA & Davoodi J 2008)."
BMGC_PW0423,BMG_PW2704,,,"Apoptotic cell death is achieved by the caspase-mediated cleavage of various vital proteins. Among caspase targets are proteins such as E-cadherin, Beta-catenin, alpha fodrin, GAS2, FADK, alpha adducin, HIP-55, and desmoglein involved in cell adhesion and maintenance of the cytoskeletal architecture. Cleavage of proteins such as APC and CIAP1 can further stimulate apoptosis by produce proapoptotic proteins (reviewed in Fischer et al., 2003. See also Wee et al., 2006 and the CASVM Caspase Substrates Database: http://www.casbase.org/casvm/squery/index.html )."
BMGC_PW0424,BMG_PW2705,,,"Once released from the mitochondria, SMAC binds to IAP family proteins displacing them from Caspase:IAP complexes liberating the active caspases."
BMGC_PW0425,BMG_PW2706,,,"In response to apoptotic signals, mitochondrial proteins are released into the cytosol and activate both caspase-dependent and -independent cell death pathways. Cytochrome c induces apoptosome formation, AIF and endonuclease G function in caspase independent apoptotic nuclear DNA damage. Smac/DIABLO and HtrA2/OMI promote both caspase activation and caspase-independent cytotoxicity (Saelens et al., 2004)."
BMGC_PW0426,BMG_PW2707,,,"Opioids are chemical substances similar to opiates, the active substances found in opium (morphine, codeine etc.). Opioid action is mediated by the receptors for endogenous opioids; peptides such as the enkephalins, the endorphins or the dynorphins. Opioids possess powerful analgesic and sedative effects, and are widely used as pain-killers. Their main side-effect is the rapid establishment of a strong addiction. Opioids receptors are G-protein coupled receptors (GPCR). There are four classes of receptors: mu (MOR), kappa (KOR) and delta (DOR), and the nociceptin receptor (NOP)."
BMGC_PW0427,BMG_PW2708,,,"Cyclic adenosine 3',5'-monophosphate (cAMP) induces gene transcription through activation of cAMP-dependent protein kinase (PKA), and subsequent phosphorylation of the transcription factor cAMP response element-binding protein, CREB, at serine-133."
BMGC_PW0428,BMG_PW2709,,,"The Ca2+-calmodulin-dependent protein kinase (CaM kinase) cascade includes three kinases: CaM-kinase kinase (CaMKK); and the CaM kinases CaMKI and CaMKIV, which are phosphorylated and activated by CaMKK. Members of this cascade respond to elevation of intracellular Ca2+ levels. CaMKK and CaMKIV localize both to the nucleus and to the cytoplasm, whereas CaMKI is only cytosolic. Nuclear CaMKIV regulates transcription through phosphorylation of several transcription factors, including CREB. In the cytoplasm, there is extensive cross-talk between CaMKK, CaMKIV and other signaling cascades, including those that involve the cAMP-dependent kinase (PKA), MAP kinases and protein kinase B (PKB/Akt)."
BMGC_PW0429,BMG_PW2710,,,"One important physiological role for Calmodulin is the regulation of adenylylcyclases. Four of the nine known adenylylcyclases are calcium sensitive, in particular type 8 (AC8)."
BMGC_PW0430,BMG_PW2711,,,"Human Ca2+/calmodulin-dependent phosphodiesterase PDE1 is activated by the binding of calmodulin in the presence of Ca(2+). PDE1 has three subtypes PDE1A, PDE1B and PDE1C and their role is to hydrolyze both cGMP and cAMP. Their role is to antagonize the increased concentration of the intracellular second messengers determined by the synthetic activity of the adenylate cyclase enzymes thus governing intracellular cAMP dynamics in response to changes in the cytosolic Ca2+ concentration. PDE1 are mainly cytosolic but different isoforms are expressed in different tissues."
BMGC_PW0431,BMG_PW2712,,,"Phospholipase A2 (PLA2) enzymes hydrolyze arachidonic acid (AA) from the sn-2 position of phospholipids. AA is a precursor of eicosanoids, lipid mediators involved in inflammtory responses. PLA2 enzymes function as regulators of phospholipid acyl turnover, either as housekeepers for membrane repair or for the production of imflammatory lipid mediators. There are diverse forms of PLA2 enyzmes including secretory (sPLA2), calcium-independent and cytosolic (cPLA2). The cPLA2 form which mediates arachidonic acid release is annotated here."
BMGC_PW0432,BMG_PW2713,,,"Calcium, as the ion Ca2+, is essential in many biological processes. The majority of Ca2+ in many organisms is bound to phosphates which form skeletal structures and also buffer Ca2+ levels in extracellular fluids (typically 1 millimolar). Intracellular free Ca2+, by contrast, is 10,000 times lower than the outside of the cell (typically 10 micromolar). This concentration gradient is used to import Ca2+ into cells where it acts as a second messenger."
BMGC_PW0433,BMG_PW2714,,,When dissociated Galpha-GTP and Gbeta-gamma can activate or inhibit different signalling cascades and effector proteins. The precise pathways depends on the identity of the alpha and beta/gamma subtypes.
BMGC_PW0434,BMG_PW2715,,,"The phospholipase C (PLC) family of enzymes is both diverse and complex. The isoforms beta, gamma and delta (each have subtypes) make up the members of this family. PLC hydrolyzes phosphatidylinositol bisphosphate (PIP2) into two second messengers, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). IP3 mobilizes intracellular calcium stores while DAG activates protein kinase C isoforms which are involved in regulatory functions."
BMGC_PW0435,BMG_PW2719,,,"Action potentials occur in electrically excitable cells such as neurons, muscles, and endocrine cells. They are initiated by transient opening of voltage dependent sodium channels, causing a rapid, large depolarization of membrane potentials that spread along the axon membrane. The action potential travels down the axon and reaches the presynaptic terminal depolarizing the membrane in the pre synaptic terminal. The depolarization causes the voltage gated Ca2+ channels to open allowing the influx of Ca2+ that signals the release of neurotransmitter into the synaptic cleft."
BMGC_PW0436,BMG_PW2720,,,"Neurotransmitter released in the synaptic cleft binds to specific receptors on the post-synaptic cell and the excess of the neurotransmitter is cleared to prevent over activation of the post-synaptic cell. The neurotransmitter is cleared by either re-uptake by the pre-synaptic neuron, diffusion in the perisynaptic area, uptake by astrocytes surrounding the synaptic cleft or enzymatic degradation of the neurotransmitter."
BMGC_PW0437,BMG_PW2721,,,Neuotransmitter uptake by astrocytes is mediated by a specific transporter located on the astrocytic membrane. The imported neurotransmitter is metabolized and transported back to the neuron.
BMGC_PW0438,BMG_PW2722,,,The neurotransmitter in the synaptic cleft released by the pre-synaptic neuron binds specific receptors located on the post-synaptic terminal. These receptors are either ion channels or G protein coupled receptors that function to transmit the signals from the post-synaptic membrane to the cell body.
BMGC_PW0439,BMG_PW2723,,,"TFIIS is a transcription factor involved in different phases of transcription, occurring in a major ubiquitous form and other tissue specific forms. TFIIS stimulates RNA Pol II complex out of elongation arrest. Other transcription factors like ELL, Elongin family members and TFIIF interact directly with elongating Pol II and increase its elongation rate. These factors have been observed to act on naked DNA templates by suppressing transient pausing by the enzyme at all or most steps of nucleotide addition. In Drosophila, ELL is found at a large number of transcriptionally active sites on polytene chromosomes. In general, ELL is suspected to have more unidentified functions. Elongin is a heterotrimeric protein complex that stimulates the overall rate of elongation. In addition, Elongin may act as an E3 Ubiquitin ligase. Ubiquitylation of RNA Pol II occurs rapidly after genotoxic assault by UV light or chemicals, and results in degradation by proteasome. The FACT complex appears to promote elongation by facilitating passage of polymerase through chromatin. All these factors contribute to the formation of a processive elongation complex centered around the RNA Pol II complex positioned on the DNA:RNA hybrid. This enables the RNA Pol II elongation complex to function as a platform that coordinates mRNA processing and export (Reviewed by Shilatifard et al., 2003)."
BMGC_PW0440,BMG_PW2724,,,"Release of phospho-IRS from the insulin receptor triggers a cascade of signalling events via PI3K, SOS, RAF and the MAP kinases."
BMGC_PW0441,BMG_PW2725,,,"Depending upon the stimulus and cell type mitogen-activated protein kinases (MAPK) signaling pathway can transmit signals to regulate many different biological processes by virtue of their ability to target multiple effector proteins (Kyriakis JM & Avruch J 2012; Yoon and Seger 2006; Shaul YD & Seger R 2007; Arthur JS & Ley SC 2013). In particular, the extracellular signal-regulated kinases MAPK3(ERK1) and MAPK1 (ERK2) are involved in diverse cellular processes such as proliferation, differentiation, regulation of inflammatory responses, cytoskeletal remodeling, cell motility and invasion through the increase of matrix metalloproteinase production (Viala E & Pouyssegur J 2004; Hsu MC et al. 2006; Dawson CW et al.2008; Kuriakose T et al. 2014).The canonical RAF:MAP2K:MAPK1/3 cascade is stimulated by various extracellular stimuli including hormones, cytokines, growth factors, heat shock and UV irradiation triggering the GEF-mediated activation of RAS at the plasma membrane and leading to the activation of the RAF MAP3 kinases. However, many physiological and pathological stimuli have been found to activate MAPK1/3 independently of RAF and RAS (Dawson CW et al. 2008; Wang J et al. 2009; Kuriakose T et al. 2014). For example, AMP-activated protein kinase (AMPK), but not RAF1, was reported to regulate MAP2K1/2 and MAPK1/3 (MEK and ERK) activation in rat hepatoma H4IIE and human erythroleukemia K562 cells in response to autophagy stimuli (Wang J et al. 2009). Tumor progression locus 2 (TPL2, also known as MAP3K8 and COT) is another MAP3 kinase which promotes MAPK1/3 (ERK)-regulated immune responses downstream of toll-like receptors (TLR), TNF receptor and IL1beta signaling pathways (Gantke T et al. 2011). In response to stimuli the cell surface receptors transmit signals inducing MAP3 kinases, e.g., TPL2, MEKK1, which in turn phosphorylate MAP2Ks (MEK1/2). MAP2K then phosphorylate and activate the MAPK1/3 (ERK1 and ERK2 MAPKs). Activated MAPK1/3 phosphorylate and regulate the activities of an ever growing pool of substrates that are estimated to comprise over 160 proteins (Yoon and Seger 2006). The majority of ERK substrates are nuclear proteins, but others are found in the cytoplasm and other organelles. Activated MAPK1/3 can translocate to the nucleus, where they phosphorylate and regulate various transcription factors, such as Ets family transcription factors (e.g., ELK1), ultimately leading to changes in gene expression (Zuber J et al. 2000)."
BMGC_PW0442,BMG_PW2726,,,Mitogen-activated protein kinase kinase MAP2K2 (also known as MEK2) is a dual threonine and tyrosine recognition kinase that phosphorylates and activates MAPK1 (ERK2) (Ohren et al. 2004; Roskoski 2012).
BMGC_PW0443,BMG_PW2727,,,SOS is recruited to the plasma membrane and mediates activation of Ras.
BMGC_PW0444,BMG_PW2728,,,"Transcription elongation by RNA polymerase II (RNAPII) is controlled by a number of trans-acting transcription elongation factors as well as by cis-acting elements. Transcription elongation is a rate-limiting step for proper mRNA production in which the phosphorylation of Pol II CTD is a crucial biochemical event. The role of CTD phosphorylation in transcription by Pol II is greatly impaired by protein kinase inhibitors such as 5,6-dichloro-1- ribofuranosylbenzimidazole (DRB), which block CTD phosphorylation and induce arrest of elongating Pol II. DRB-sensitive activation Pol II CTD during elongation has enabled the isolation of two sets of factors -Negative Elongation Factors (NELF) and DRB sensitivity inducing factor (DSIF). P-Tefb is a DRB-sensitive, cyclin-dependent CTD kinase composed of Cdk9 that carries out Serine-2 phosphorylation of Pol II CTD during elongation. The mechanism by which DSIF, NELF and P-TEFb act together in Pol II-regulated elongation is yet to be fully understood. Various biochemical evidences point to a model in which DSIF and NELF negatively regulate elongation through interactions with polymerase containing a hypophosphorylated CTD. Subsequent phosphorylation of the Pol II CTD by P-Tefb might promote elongation by inhibiting interactions of DSIF and NELF with the elongation complex."
BMGC_PW0445,BMG_PW2729,,,"During S phase of the cell cycle, RB1 is dephosphorylated by the PP2A protein phosphatase complex. Unphosphorylated RB1 associates with DNA damage sites in S phase, preventing initiation of DNA replication from these sites (Knudsen et al. 2000, Avni et al. 2003)."
BMGC_PW0446,BMG_PW2730,,,"Under specific conditions, Cyclin B, a mitotic cyclin, can inhibit the functions of pre-replicative complex. E2F1 activates Cdc25A protein which regulates Cyclin B in a positive manner. Cyclin B/Cdk1 function is restored which leads to the disruption of pre-replicative complex. This phenomenon has been demonstrated by Bosco et al (2001) in Drosophila."
BMGC_PW0447,BMG_PW2731,,,"Progression through G1 and G1 to S-phase transition that initiates DNA synthesis involve many complexes that are regulated by RB1:E2F pathway. RB1:E2F pathway plays a key role in gene expression regulation in proliferating and differentiated cells. As a repressor, E2F remains bound to RB1; it can activate the expression of S-phase genes involved in DNA replication after the phosphorylation of RB1. E2F proteins regulate expression of genes involved in various processes thereby forming interlinks between cell cycle, DNA synthesis, DNA damage recognition etc. In this module, activation of replication related genes by E2F1 and two ways by which E2F1 regulates DNA replication initiation are annotated."
BMGC_PW0448,BMG_PW2732,,,"As a result of binding to Bid, Bax oligomerizes and integrates in the outer mitochondrial membrane, triggering cytochrome c release. Bax mitochondrial membrane insertion triggered by Bid may represent a key step in pathways leading to apoptosis (Eskes et al., 2000)."
BMGC_PW0449,BMG_PW2733,,,"The BH3-only members act as sentinels that selectively trigger apoptosis in response to developmental cues or stress-signals like DNA damages. Widely expressed mammalian BH3-only proteins are thought to act by binding to and neutralizing their pro-survival counterparts. Activation of BH3-only proteins directly or indirectly results in the activation of proapoptotic BAX and BAK to trigger cell death. Anti-apoptotic BCL-2 or BCL-XL may bind and sequester BH3-only molecules to prevent BAX, BAK activation. The individual BH3-only members are held in check by various mechanisms with in the cells. They are recruited for death duties in response to death cues by diverse activation processes.The mechanisms involved in activation and release of BH3-only proteins for apoptosis will be discussed in this section. The following figure has been reproduced here with the kind permission from the authors."
BMGC_PW0450,BMG_PW2734,,,"Hydrolysis of phosphatidyl inositol-bisphosphate (PIP2) by phospholipase C (PLC) produces diacylglycerol (DAG) and inositol triphosphate (IP3). Both are potent second messengers. IP3 diffuses into the cytosol, but as DAG is a hydrophobic lipid it remains within the plasma membrane. IP3 stimulates the release of calcium ions from the smooth endoplasmic reticulum, while DAG activates the conventional and unconventional protein kinase C (PKC) isoforms, facilitating the translocation of PKC from the cytosol to the plasma membrane. The effects of DAG are mimicked by tumor-promoting phorbol esters. DAG is also a precursor for the biosynthesis of prostaglandins, the endocannabinoid 2-arachidonoylglycerol and an activator of a subfamily of TRP-C (Transient Receptor Potential Canonical) cation channels 3, 6, and 7."
BMGC_PW0451,BMG_PW2735,,,"The SNARE (SNAp REceptor) family of proteins are critical components of the machinery required for membrane fusion (Söllner et al. 1993, Wu et al. 2017). SNAREs can be grouped into three broad subfamilies: synaptosomal-associated proteins (SNAPs), vesicle-associated membrane proteins (VAMPs) and syntaxins. SNAPs contain two SNARE motifs and lack transmembrane domains, instead they are anchored to the membrane by thioester-linked acyl groups (Hong 2005). VAMPS or R-SNAREs have two subfamilies: short VAMPs or brevins and long VAMPs or longins. Syntaxins are evolutionarily less-well conserved, but except STX11 are transmembrane proteins (Hong 2005). Several SNARE proteins including Syntaxin-2 (STX2), STX4, STX11 and Vesicle-associated membrane protein 8 (VAMP8) are thought to be involved in platelet granule secretion (Golebiewska et al. 2013)."
BMGC_PW0452,BMG_PW2736,,,"The GPVI receptor is a complex of the GPVI protein with Fc epsilon R1 gamma (FcR). The Src family kinases Fyn and Lyn constitutively associate with the GPVI-FcR complex in platelets and initiate platelet activation through phosphorylation of the immunoreceptor tyrosine-based activation motif (ITAM) in the FcR gamma chain, leading to binding and activation of the tyrosine kinase Syk. Downstream of Syk, a series of adapter molecules and effectors lead to platelet activation. The GPVI receptor signaling cascade is similar to that of T- and B-cell immune receptors, involving the formation of a signalosome composed of adapter and effector proteins. At the core of the T-cell receptor signalosome is the transmembrane adapter LAT and two cytosolic adapters SLP-76 and Gads. While LAT is essential for signalling to PLCgamma1 downstream of the T-cell receptor, the absence of LAT in platelets only impairs the activation of PLCgamma2, the response to collagen and GPVI receptor ligands remains sufficient to elicit a full aggregation response. In contrast, GPVI signalling is almost entirely abolished in the absence of SLP-76."
BMGC_PW0453,BMG_PW2737,,,"Platelets function as exocytotic cells, secreting a plethora of effector molecules at sites of vascular injury. Platelets contain a number of distinguishable storage granules including alpha granules, dense granules and lysosomes. On activation platelets release a variety of proteins, largely from storage granules but also as the result of apparent cell lysis. These act in an autocrine or paracrine fashion to modulate cell signaling. Alpha granules contain mainly polypeptides such as fibrinogen, von Willebrand factor, growth factors and protease inhibitors that that supplement thrombin generation at the site of injury. Dense granules contain small molecules, particularly adenosine diphosphate (ADP), adenosine triphosphate (ATP), serotonin and calcium, all recruit platelets to the site of injury. The molecular mechanism which facilitates granule release involves soluble NSF attachment protein receptors (SNAREs), which assemble into complexes to form a universal membrane fusion apparatus. Although all cells use SNAREs for membrane fusion, different cells possess different SNARE isoforms. Platelets and chromaffin cells use many of the same chaperone proteins to regulate SNARE-mediated secretion (Fitch-Tewfik & Flaumenhaft 2013)."
BMGC_PW0454,BMG_PW2738,,,"Second messengers (calcium, diacylglycerol, inositol 1,4,5-trisphosphate, and phosphatidyinositol 3,4,5-trisphosphate) trigger signaling pathways: NF-kappaB is activated via protein kinase C beta, RAS via RasGRP proteins, NF-AT via calcineurin, and AKT via PDK1 (reviewed in Shinohara and Kurosaki 2009, Stone 2006)."
BMGC_PW0455,BMG_PW2739,,,"DAG and calcium activate protein kinase C beta (PKC-beta, Kochs et al. 1991) which phosphorylates CARMA1 and other proteins (Sommer et al. 2005). Phosphorylated CARMA1 recruits BCL10 and MALT1 to form the CBM complex (Sommer et al. 2005, Tanner et al. 2007) which, in turn, recruits the kinase TAK1 and the IKK complex (Sommer et al. 2005, Shinohara et al. 2005 using chicken cells). TAK1 phosphorylates the IKK-beta subunit, activating it (Wang et al. 2001). The IKK complex then phosphorylates IkB complexed with NF-kappaB dimers in the cytosol (Zandi et al. 1998, Burke et al. 1999, Heilker et al. 1999), resulting in the degradation of IkB (Miyamoto et al. 1994, Traenckner et al. 1994, Alkalay et al. 1995, DiDonato et al. 1995, Li et al. 1995, Lin et al. 1995, Scherer et al. 1995, Chen et al. 1995). NF-kappaB dimers are thereby released and are translocated to the nucleus where they activate transcription (Baeuerle and Baltimore 1988, Blank et al. 1991, Ghosh et al. 2008, Fagerlund et al. 2008)."
BMGC_PW0456,BMG_PW2740,,,"RasGRP1 and RasGRP3 bind diacylglycerol at the plasma membrane (Lorenzo et al. 2001) and are phosphorylated by protein kinase C (Teixeira et al. 2003, Zheng et al. 2005). Phosphorylated RasGRP1 (Roose et al. 2007) and RasGRP3 (Ohba et al. 2000, Yamashita et al. 2000, Rebhun et al. 2000, Lorenzo et al. 2001) then catalyze the exchange of GDP for GTP bound by RAS, thereby activating RAS."
BMGC_PW0457,BMG_PW2741,,,"Interferon-stimulated gene 15 (ISG15) is a member of the ubiquitin-like (Ubl) family. It is strongly induced upon exposure to type I Interferons (IFNs), viruses, bacterial LPS, and other stresses. Once released the mature ISG15 conjugates with an array of target proteins, a process termed ISGylation. ISGylation utilizes a mechanism similar to ubiquitination, requiring a three-step enzymatic cascade. UBE1L is the ISG15 E1 activating enzyme which specifically activates ISG15 at the expense of ATP. ISG15 is then transfered from E1 to the E2 conjugating enzyme UBCH8 and then to the target protein with the aid of an ISG15 E3 ligase, such as HERC5 and EFP. Hundreds of target proteins for ISGylation have been identified. Several proteins that are part of antiviral signaling pathways, such as RIG-I, MDA5, Mx1, PKR, filamin B, STAT1, IRF3 and JAK1, have been identified as targets for ISGylation. ISG15 also conjugates some viral proteins, inhibiting viral budding and release. ISGylation appears to act either by disrupting the activity of a target protein and/or by altering its localization within the cell."
BMGC_PW0458,BMG_PW2742,,,"Interferons activate JAK–STAT signaling, which leads to the transcriptional induction of hundreds of IFN-stimulated genes (ISGs). The ISG-encoded proteins include direct effectors which inhibit viral infection through diverse mechanisms as well as factors that promote adaptive immune responses. The ISG proteins generated by IFN pathways plays key roles in the induction of innate and adaptive immune responses."
BMGC_PW0459,BMG_PW2743,,,"Mammalian fertilization comprises sperm migration through the female reproductive tract, biochemical and morphological changes to sperm, and sperm-egg interaction in the oviduct. Although the broad concepts of fertilization are well defined, our understanding of the biochemical mechanisms underlying sperm-egg binding is limited."
BMGC_PW0460,BMG_PW2744,,,"Meiotic synapsis is the stable physical pairing of homologous chromosomes that begins in leptonema of prophase I and lasts until anaphase of prophase I. First, short segments of axial elements form along chromosomes. Telomeres then cluster at a region of the inner nuclear membrane and axial elements extend and fuse along the length of the chromosomes. Subsequent to the initiation of recombination transverse filaments of SYCP1 link axial/lateral elements to a central element containing SYCE1 and SYCE2, thus forming the synaptonemal complex (reviewed in Yang and Wang 2009). Unsynapsed regions are silenced during pachynema by recruitment of BRCA1 and ATR, which phosphorylates histone H2AX (reviewed in Inagaki et al. 2010)."
BMGC_PW0461,BMG_PW2750,,,"The first line of defense against infectious agents involves an active recruitment of phagocytes to the site of infection. Recruited cells include polymorhonuclear (PMN) leukocytes (i.e., neutrophils) and monocytes/macrophages, which function together as innate immunity sentinels (Underhill DM & Ozinsky A 2002; Stuart LM & Ezekowitz RA 2005; Flannagan RS et al. 2012). Dendritic cells are also present, serving as important players in antigen presentation for ensuing adaptive responses (Savina A & Amigorena S 2007). These cell types are able to bind and engulf invading microbes into a membrane-enclosed vacuole - the phagosome, in a process termed phagocytosis. Phagocytosis can be defined as the receptor-mediated engulfment of particles greater than 0.5 micron in diameter. It is initiated by the cross-linking of host cell membrane receptors following engagement with their cognate ligands on the target surface (Underhill DM & Ozinsky A 2002; Stuart LM & Ezekowitz RA 2005; Flannagan RS et al. 2012). When engulfed by phagocytes, microorganisms are exposed to a number of host defense microbicidal events within the resulting phagosome. These include the production of reactive oxygen and nitrogen species (ROS and RNS, RONS) by specialized enzymes (Fang FC et al. 2004; Kohchi C et al. 2009; Gostner JM et al. 2013; Vatansever F et al. 2013). NADPH oxidase (NOX) complex consume oxygen to produce superoxide radical anion (O2.-) and hydrogen peroxide (H2O2) (Robinson et al. 2004). Induced NO synthase (iNOS) is involved in the production of NO, which is the primary source of all RNS in biological systems (Evans TG et al. 1996). The phagocyte NADPH oxidase and iNOS are expressed in both PMN and mononuclear phagocytes and both cell types have the capacity for phagosomal burst activity. However, the magnitude of ROS generation in neutrophils far exceeds that observed in macrophages (VanderVen BC et al. 2009). Macrophages are thought to produce considerably more RNS than neutrophils (Fang FC et al. 2004; Nathan & Shiloh 2000). The presence of RONS characterized by a relatively low reactivity, such as H2O2, O2˙− or NO, has no deleterious effect on biological environment (Attia SM 2010; Weidinger A & and Kozlov AV 2015). Their activity is controlled by endogenous antioxidants (both enzymatic and non-enzymatic) that are induced by oxidative stress. However the relatively low reactive species can initiate a cascade of reactions to generate more damaging “secondary” species such as hydroxyl radical (•OH), singlet oxygen or peroxinitrite (Robinson JM 2008; Fang FC et al. 2004). These ""secondary"" RONS are extremely toxic causing irreversible damage to all classes of biomolecules (Weidinger A & and Kozlov AV 2015; Fang FC et al. 2004; Kohchi C et al. 2009; Gostner JM et al. 2013; Vatansever F et al. 2013). Although macrophages and neutrophils use similar mechanisms for the internalization of targets, there are differences in how they perform phagocytosis and in the final outcome of the process (Tapper H & Grinstein S 1997; Vierira OV et al. 2002). Once formed, the phagosome undergoes an extensive maturation process whereby it develops into a microbicidal organelle able to eliminate the invading pathogen. Maturation involves re-modeling both the membrane of the phagosome and its luminal contents (Vierira OV et al. 2002). In macrophages, phagosome formation and maturation follows a series of strictly coordinated membrane fission/fusion events between the phagosome and compartments of the endo/lysosomal network gradually transforming the nascent phagosome into a phagolysosome, a degradative organelle endowed with potent microbicidal properties (Zimmerli S et al. 1996; Vierira OV et al. 2002). Neutrophils instead contain a large number of preformed granules such as azurophilic and specific granules that can rapidly fuse with phagosomes delivering antimicrobial substances (Karlsson A & Dahlgren C 2002; Naucler C et al. 2002; Nordenfelt P and Tapper H 2011). Phagosomal pH dynamics may also contribute to the maturation process by regulating membrane traffic events. The microbicidal activity of macrophages is characterized by progressive acidification of the lumen (down to pH 4–5) by the proton pumping vATPase. A low pH is a prerequisite for optimal enzymatic activity of most late endosomal/lysosomal hydrolases reported in macrophages. Neutrophil phagosome pH regulation differs significantly from what is observed in macrophages (Nordenfelt P and Tapper H 2011; Winterbourn CC et al. 2016). The massive activation of the oxidative burst is thought to result in early alkalization of neutrophil phagosomes which is linked to proton consumption during the generation of hydrogen peroxide (Segal AW et al. 1981; Levine AP et al. 2015). Other studies showed that neutrophil phagosome maintained neutral pH values before the pH gradually decreased (Jankowski A et al. 2002). Neutrophil phagosomes also exhibited a high proton leak, which was initiated upon activation of the NADPH oxidase, and this activation counteracted phagosomal acidification (Jankowski A et al. 2002). The Reactome module describes ROS and RNS production by phagocytic cells. The module includes cell-type specific events, for example, myeloperoxidase (MPO)-mediated production of hypochlorous acid in neutrophils. It also highlights differences between phagosomal pH dynamics in neutrophils and macrophages. The module describes microbicidal activity of selective RONS such as hydroxyl radical or peroxynitrite. However, detection of any of these species in the phagosomal environment is subject to many uncertainties (Nüsse O 2011; Erard M et al. 2018). The mechanisms by which reactive oxygen/nitrogen species kill pathogens in phagocytic immune cells are still not fully understood."
BMGC_PW0462,BMG_PW2751,,,"A number of skeletal and developmental diseases have been shown to arise as a result of mutations in the FGFR1, 2 and 3 genes. These include dwarfism syndromes (achondroplasia, hypochondroplasia and the neonatal lethal disorders thanatophoric dysplasia I and II), as well as craniosynostosis disorders such as Pfeiffer, Apert, Crouzon, Jackson-Weiss and Muenke syndromes (reviewed in Webster and Donoghue 1997; Burke, 1998, Cunningham, 2007; Harada, 2009). These mutations fall into four general regions of the receptor: a) the immunoglobulin (Ig)-like domain II-III linker region, b) the alternatively spliced second half of the Ig III domain, c) the transmembrane domain and d) the tyrosine kinase domain (reviewed in Webster and Donoghue, 1997). With the exception of mutations in class b), which affect only the relevant splice variant, these mutations may be present in either the 'b' or 'c' isoforms. These activating mutations affect FGFR function by altering or expanding the ligand-binding range of the receptors (see for instance Ibrahimi, 2004a), by promoting ligand-independent dimerization (for instance, Galvin,1996; Neilson and Friesel, 1996; d'Avis,1998) or by increasing the activity of the kinase domain (for instance, Webster, 1996; Naski, 1996; Tavormina, 1999; Bellus, 2000). Thus, a number of the point mutations found in FGFR receptors alter their activity without altering their intrinsic kinase activity. Many of the mutations that promote constitutive dimerization do so by creating or removing cysteine residues; the presence of an unpaired cysteine in the receptor is believed to promote dimerization through the formation of intramolecular disulphide bonds (Galvin, 1996; Robertson, 1998). Paralogous mutations at equivalent positions have been identified in more than one FGF receptor, sometimes giving rise to different diseases. For instance, mutation of the highly conserved FGFR2 Ser252-Pro253 dipeptide in the region between the second and third Ig domain is responsible for virtually all cases of Apert Syndrome (Wilkie, 1995), while paralogous mutations in FGFR1 (S252R) and FGFR3 (P250R) are associated with Pfeiffer and Crouzon syndromes, respectively (Bellus, 1996). FGFR4 is unique in that mutations of this gene are not known to be associated with any developmental disorders. Recently, many of the same activating mutations in the FGFR genes that have been characterized in skeletal and developmental disorders have begun to be identified in a range of cancers (reviewed in Turner and Gross, 2010; Greulich and Pollock, 2011; Wesche, 2011). The best established link between a somatic mutation of an FGFR and the development of cancer is in the case of FGFR3, where 50% of bladder cancers have mutations in the FGFR3 coding sequence. Of these mutations, which largely match the activating mutations seen in thanatophoric dysplasias, over half occur at a single residue (S249C) (Cappellen, 1999; van Rhijn, 2002). Activating mutations have also been identified in the coding sequences of FGFR1, 2 and 4 (for review, see Wesche, 2011) In addition to activating point mutations, the FGFR1, 2 and 3 genes are subject to misregulation in cancer through gene amplification and translocation events, which are thought to lead to overexpression and ligand-independent dimerization (Weiss, 2010; Turner, 2010; Kunii, 2008; Takeda, 2007; Chesi, 1997; Avet-Loiseau, 1998; Ronchetti, 2001). It is important to note, however, that in each of these cases, the amplification or translocation involve large genomic regions encompassing additional genes, and the definitive roles of the FGFR genes in promoting oncogenesis has not been totally established. In the case of FGFR1, translocation events also give rise to FGFR1 fusion proteins that contain the intracellular kinase domain of the receptor fused to a dimerization domain from the partner gene. These fusions, which are expressed in a pre-leukemic myeloproliferative syndrome, dimerize constitutively based on the dimerization domain provided by the fusion partner and are constitutively active (reviewed in Jackson, 2010)."
BMGC_PW0463,BMG_PW2752,,,"ERBB2, also known as HER2 or NEU, is a receptor tyrosine kinase (RTK) belonging to the EGFR family. ERBB2 possesses an extracellular domain that does not bind any known ligand, contrary to other EGFR family members, a single transmembrane domain, and an intracellular domain consisting of an active kinase and a C-tail with multiple tyrosine phosphorylation sites. Inactive ERBB2 is associated with a chaperone heat shock protein 90 (HSP90) and its co-chaperone CDC37 (Xu et al. 2001, Citri et al. 2004, Xu et al. 2005). In addition, ERBB2 is associated with ERBB2IP (also known as ERBIN or LAP2), a protein responsible for proper localization of ERBB2. In epithelial cells, ERBB2IP restricts expression of ERBB2 to basolateral plasma membrane regions (Borg et al. 2000). ERBB2 becomes activated by forming a heterodimer with another ligand-activated EGFR family member, either EGFR, ERBB3 or ERBB4, which is accompanied by dissociation of chaperoning proteins HSP90 and CDC37 (Citri et al. 2004), as well as ERBB2IP (Borg et al. 2000) from ERBB2. ERBB2 heterodimers function to promote cell proliferation, cell survival and differentiation, depending on the cellular context. ERBB2 can also be activated by homodimerization when it is overexpressed, in cancer for example. In cells expressing both ERBB2 and EGFR, EGF stimulation of EGFR leads to formation of both ERBB2:EGFR heterodimers (Wada et al. 1990, Karunagaran et al. 1996) and EGFR homodimers. Heterodimers of ERBB2 and EGFR trans-autophosphorylate on twelve tyrosine residues, six in the C-tail of EGFR and six in the C-tail of ERBB2 - Y1023, Y1139, Y1196, Y1221, Y1222 and Y1248 (Margolis et al. 1989, Hazan et al. 1990,Walton et al. 1990, Helin et al. 1991, Ricci et al. 1995, Pinkas-Kramarski 1996). Phosphorylated tyrosine residues in the C-tail of EGFR and ERBB2 serve as docking sites for downstream signaling molecules. Three key signaling pathways activated by ERBB2:EGFR heterodimers are RAF/MAP kinase cascade, PI3K-induced AKT signaling, and signaling by phospholipase C gamma (PLCG1). Downregulation of EGFR signaling is mediated by ubiquitin ligase CBL, and is shown under Signaling by EGFR. In cells expressing ERBB2 and ERBB3, ERBB3 activated by neuregulin NRG1 or NRG2 binding (Tzahar et al. 1994) forms a heterodimer with ERBB2 (Pinkas-Kramarski et al. 1996, Citri et al. 2004). ERBB3 is the only EGFR family member with no kinase activity, and can only function in heterodimers, with ERBB2 being its preferred heterodimerization partner. After heterodimerization, ERBB2 phosphorylates ten tyrosine residues in the C-tail of ERBB3, Y1054, Y1197, Y1199, Y1222, Y1224, Y1260, Y1262, Y1276, Y1289 and Y1328 (Prigent et al. 1994, Pinkas-Kramarski et al. 1996, Vijapurkar et al. 2003, Li et al. 2007) that subsequently serve as docking sites for downstream signaling molecules, resulting in activation of PI3K-induced AKT signaling and RAF/MAP kinase cascade. Signaling by ERBB3 is downregulated by the action of RNF41 ubiquitin ligase, also known as NRDP1. In cells expressing ERBB2 and ERBB4, ligand stimulated ERBB4 can either homodimerize or form heterodimers with ERBB2 (Li et al. 2007), resulting in trans-autophosphorylation of ERBB2 and ERBB4 on C-tail tyrosine residues that will subsequently serve as docking sites for downstream signaling molecules, leading to activation of RAF/MAP kinase cascade and, in the case of ERBB4 CYT1 isoforms, PI3K-induced AKT signaling (Hazan et al. 1990, Cohen et al. 1996, Li et al. 2007, Kaushansky et al. 2008). Signaling by ERBB4 is downregulated by the action of WWP1 and ITCH ubiquitin ligases, and is shown under Signaling by ERBB4."
BMGC_PW0464,BMG_PW2754,,,"Oxygen plays a central role in the functioning of human cells: it is both essential for normal metabolism and toxic. Here we have annotated one aspect of cellular responses to oxygen, the role of hypoxia-inducible factor in regulating cellular transcriptional responses to changes in oxygen availability. In the presence of oxygen members of the transcription factor family HIF-alpha, comprising HIF1A, HIF2A (EPAS1), and HIF3A, are hydroxylated on proline residues by PHD1 (EGLN2), PHD2 (EGLN1), and PHD3 (EGLN3) and on asparagine residues by HIF1AN (FIH) (reviewed in Pouyssegur et al. 2006, Semenza 2007, Kaelin and Ratcliffe 2008, Nizet and Johnson 2009, Brahimi-Horn and Pouyssegur 2009, Majmundar et al. 2010, Loenarz and Schofield 2011). Both types of reaction require molecular oxygen as a substrate and it is probable that at least some HIF-alpha molecules carry both hydroxylated asparagine and hydroxylated proline (Tian et al. 2011). Hydroxylated asparagine interferes with the ability of HIF-alpha to interact with p300 and CBP while hydroxylated proline facilitates the interaction of HIF-alpha with the E3 ubiquitin ligase VHL, causing ubiquitination and proteolysis of HIF-alpha. Hypoxia inhibits both types of hydroxylation, resulting in the stabilization of HIF-alpha, which then enters the nucleus, binds HIF-beta, and recruits p300 and CBP to activate target genes such as EPO and VEGF."
BMGC_PW0465,BMG_PW2755,,,"HIF-alpha subunits, comprising HIF1A (Bruick and McKnight 2001, Ivan et al. 2001, Jaakkola et al. 2001), HIF2A (Percy et al. 2008, Furlow et al. 2009), and HIF3A (Maynard et al. 2003), are hydroxylated at proline residues by the prolyl hydroxylases PHD1 (EGLN2), PHD2 (EGLN1), and PHD3 (EGLN3) (Bruick and McKnight 2001, Berra et al. 2003, Hirsila et al. 2003, Metzen et al. 2003, Tuckerman et al. 2004, Appelhoff et al. 2004, Fedulova et al. 2007, Tian et al. 2011). The reaction requires molecular oxygen as a substrate and so it is inhibited by hypoxia. PHD2 (EGLN1) is predominantly cytosolic (Metzen et al. 2003) and is the key determinant in the regulation of HIF-alpha subunits by oxygen (Berra et al. 2003). HIF-alpha subunits hydroxylated at proline residues are bound by VHL, an E3 ubiquitin ligase in a complex containing ElonginB, Elongin C, CUL2, and RBX1. VHL ubiquitinates HIF-alpha, resulting in destruction of HIF-alpha by proteolysis. Hypoxia inhibits proline hydroxylation and interaction with VHL, stabilizing HIF-alpha, which transits to the nucleus and activates gene expression."
BMGC_PW0466,BMG_PW2756,,,"Signaling by EGFR is frequently activated in cancer through activating mutations in the coding sequence of the EGFR gene, resulting in expression of a constitutively active mutant protein. Epidermal growth factor receptor kinase domain mutants are present in ~16% of non-small-cell lung cancers (NSCLCs), but are also found in other cancer types, such as breast cancer, colorectal cancer, ovarian cancer and thyroid cancer. EGFR kinase domain mutants harbor activating mutations in exons 18-21 which code for the kinase domain (amino acids 712-979) . Small deletions, insertions or substitutions of amino acids within the kinase domain lock EGFR in its active conformation in which the enzyme can dimerize and undergo autophosphorylation spontaneously, without ligand binding (although ligand binding ability is preserved), and activate downstream signaling pathways that promote cell survival (Greulich et al. 2005, Zhang et al. 2006, Yun et al. 2007, Red Brewer et al. 2009). Point mutations in the extracellular domain of EGFR are frequently found in glioblastoma. Similar to kinase domain mutations, point mutations in the extracellular domain result in constitutively active EGFR proteins that signal in the absence of ligands, but ligand binding ability and responsiveness are preserved (Lee et al. 2006). EGFR kinase domain mutants need to maintain association with the chaperone heat shock protein 90 (HSP90) for proper functioning (Shimamura et al. 2005, Lavictoire et al. 2003). CDC37 is a co-chaperone of HSP90 that acts as a scaffold and regulator of interaction between HSP90 and its protein kinase clients. CDC37 is frequently over-expressed in cancers involving mutant kinases and acts as an oncogene (Roe et al. 2004, reviewed by Gray Jr. et al. 2008). Over-expression of the wild-type EGFR or EGFR cancer mutants results in aberrant activation of downstream signaling cascades, namely RAS/RAF/MAP kinase signaling and PI3K/AKT signaling, and possibly signaling by PLCG1, which leads to increased cell proliferation and survival, providing selective advantage to cancer cells that harbor activating mutations in the EGFR gene (Sordella et al. 2004, Huang et al. 2007). While growth factor activated wild-type EGFR is promptly down-regulated by internalization and degradation, cancer mutants of EGFR demonstrate prolonged activation (Lynch et al. 2004). Association of HSP90 with EGFR kinase domain mutants negatively affects CBL-mediated ubiquitination, possibly through decreasing the affinity of EGFR kinase domain mutants for phosphorylated CBL, so that CBL dissociates from the complex upon phosphorylation and cannot perform ubiquitination (Yang et al. 2006, Padron et al. 2007). Various molecular therapeutics are being developed to target aberrantly activated EGFR in cancer. Non-covalent (reversible) small tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib, selectively bind kinase domain of EGFR, competitively inhibiting ATP binding and subsequent autophosphorylation of EGFR dimers. EGFR kinase domain mutants sensitive to non-covalent TKIs exhibit greater affinity for TKIs than ATP compared with the wild-type EGFR protein, and are therefore preferential targets of non-covalent TKI therapeutics (Yun et al. 2007). EGFR proteins that harbor point mutations in the extracellular domain also show sensitivity to non-covalent tyrosine kinase inhibitors (Lee et al. 2006). EGFR kinase domain mutants harboring small insertions in exon 20 or a secondary T790M mutation are resistant to reversible TKIs (Balak et al. 2006) due to increased affinity for ATP (Yun et al. 2008), and are targets of covalent (irreversible) TKIs that form a covalent bond with EGFR cysteine residue C397. However, effective concentrations of covalent TKIs also inhibit wild-type EGFR, causing severe side effects (Zhou et al. 2009). Hence, covalent TKIs have not shown much promise in clinical trials (Reviewed by Pao and Chmielecki in 2010)."
BMGC_PW0467,BMG_PW2757,,,"ERBB4, also known as HER4, belongs to the ERBB family of receptors, which also includes ERBB1 (EGFR/HER1), ERBB2 (HER2/NEU) and ERBB3 (HER3). Similar to EGFR, ERBB4 has an extracellular ligand binding domain, a single transmembrane domain and a cytoplasmic domain which contains an active tyrosine kinase and a C-tail with multiple phosphorylation sites. At least three and possibly four splicing isoforms of ERBB4 exist that differ in their C-tail and/or the extracellular juxtamembrane regions: ERBB4 JM-A CYT1, ERBB4 JM-A CYT2 and ERBB4 JM-B CYT1 (the existence of ERBB4 JM-B CYT2 has not been confirmed). ERBB4 becomes activated by binding one of its seven ligands, three of which, HB-EGF, epiregulin EPR and betacellulin BTC, are EGF-like (Elenius et al. 1997, Riese et al. 1998), while four, NRG1, NRG2, NRG3 and NRG4, belong to the related neuregulin family (Tzahar et al. 1994, Carraway et al. 1997, Zhang et al. 1997, Hayes et al. 2007). Upon ligand binding, ERBB4 forms homodimers (Sweeney et al. 2000) or it heterodimerizes with ERBB2 (Li et al. 2007). Dimers of ERBB4 undergo trans-autophosphorylation on tyrosine residues in the C-tail (Cohen et al. 1996, Kaushansky et al. 2008, Hazan et al. 1990, Li et al. 2007), triggering downstream signaling cascades. The pathway Signaling by ERBB4 only shows signaling by ERBB4 homodimers. Signaling by heterodimers of ERBB4 and ERBB2 is shown in the pathway Signaling by ERBB2. Ligand-stimulated ERBB4 is also able to form heterodimers with ligand-stimulated EGFR (Cohen et al. 1996) and ligand-stimulated ERBB3 (Riese et al. 1995). Dimers of ERBB4 with EGFR and dimers of ERBB4 with ERBB3 were demonstrated in mouse cell lines in which human ERBB4 and EGFR or ERBB3 were exogenously expressed. These heterodimers undergo trans-autophosphorylation. The promiscuous heteromerization of ERBBs adds combinatorial diversity to ERBB signaling processes. As ERBB4 binds more ligands than other ERBBs, but has restricted expression, ERBB4 expression channels responses to ERBB ligands. The signaling capabilities of the four receptors have been compared (Schulze et al. 2005). As for other receptor tyrosine kinases, ERBB4 signaling effectors are largely dictated through binding of effector proteins to ERBB4 peptides that are phosphorylated upon ligand binding. All splicing isoforms of ERBB4 possess two tyrosine residues in the C-tail that serve as docking sites for SHC1 (Kaushansky et al. 2008, Pinkas-Kramarski et al. 1996, Cohen et al. 1996). Once bound to ERBB4, SHC1 becomes phosphorylated on tyrosine residues by the tyrosine kinase activity of ERBB4, which enables it to recruit the complex of GRB2 and SOS1, resulting in the guanyl-nucleotide exchange on RAS and activation of RAF and MAP kinase cascade (Kainulainen et al. 2000). The CYT1 isoforms of ERBB4 also possess a C-tail tyrosine residue that, upon trans-autophosphorylation, serves as a docking site for the p85 alpha subunit of PI3K (Kaushansky et al. 2008, Cohen et al. 1996), leading to assembly of an active PI3K complex that converts PIP2 to PIP3 and activates AKT signaling (Kainulainen et al. 2000). Besides signaling as a conventional transmembrane receptor kinase, ERBB4 differs from other ERBBs in that JM-A isoforms signal through efficient release of a soluble intracellular domain. Ligand activated homodimers of ERBB4 JM-A isoforms (ERBB4 JM-A CYT1 and ERBB4 JM-A CYT2) undergo proteolytic cleavage by ADAM17 (TACE) in the juxtamembrane region, resulting in shedding of the extracellular domain and formation of an 80 kDa membrane bound ERBB4 fragment known as ERBB4 m80 (Rio et al. 2000, Cheng et al. 2003). ERBB4 m80 undergoes further proteolytic cleavage, mediated by the gamma-secretase complex, which releases the soluble 80 kDa ERBB4 intracellular domain, known as ERBB4 s80 or E4ICD, into the cytosol (Ni et al. 2001). ERBB4 s80 is able to translocate to the nucleus, promote nuclear translocation of various transcription factors, and act as a transcription co-factor. For example, in mammary cells, ERBB4 binds SH2 transcription factor STAT5A. ERBB4 s80 shuttles STAT5A to the nucleus, and actsa as a STAT5A co-factor in binding to and promoting transcription from the beta-casein (CSN2) promoter, and may be involved in the regulation of other lactation-related genes (Jones et al. 1999, Williams et al. 2004, Muraoka-Cook et al. 2008). ERBB4 s80 binds activated estrogen receptor in the nucleus and acts as a transcriptional co-factor in promoting transcription of some estrogen-regulated genes, including progesterone receptor gene NR3C3 and CXCL12 (SDF1) (Zhu et al. 2006). In neuronal precursors, ERBB4 s80 binds the complex of TAB and NCOR1, helps to move the complex into the nucleus, and is a co-factor of TAB:NCOR1-mediated inhibition of expression of astrocyte differentiation genes GFAP and S100B (Sardi et al. 2006). The C-tail of ERBB4 possesses several WW-domain binding motifs (three in CYT1 isoform and two in CYT2 isoform), which enable interaction of ERBB4 with WW-domain containing proteins. ERBB4 s80, through WW-domain binding motifs, interacts with YAP1 transcription factor, a known proto-oncogene, and is a co-regulator of YAP1-mediated transcription in association with TEAD transcription factors (Komuro et al. 2003, Omerovic et al. 2004). Hence, the WW binding motif couples ERBB4 to the major effector arm of the HIPPO signaling pathway. The tumor suppressor WWOX, another WW-domain containing protein, competes with YAP1 in binding to ERBB4 s80 and prevents translocation of ERBB4 s80 to the nucleus (Aqeilan et al. 2005). WW-domain binding motifs in the C-tail of ERBB4 play an important role in the downregulation of ERBB4 receptor signaling, enabling the interaction of intact ERBB4, ERBB4 m80 and ERBB4 s80 with NEDD4 family of E3 ubiquitin ligases WWP1 and ITCH. The interaction of WWP1 and ITCH with intact ERBB4 is independent of receptor activation and autophosphorylation. Binding of WWP1 and ITCH ubiquitin ligases leads to ubiquitination of ERBB4 and its cleavage products, and subsequent degradation through both proteasomal and lysosomal routes (Omerovic et al. 2007, Feng et al. 2009). In addition, the s80 cleavage product of ERBB4 JM-A CYT-1 isoform is the target of NEDD4 ubiquitin ligase. NEDD4 binds ERBB4 JM-A CYT-1 s80 (ERBB4jmAcyt1s80) through its PIK3R1 interaction site and mediates ERBB4jmAcyt1s80 ubiquitination, thereby decreasing the amount of ERBB4jmAcyt1s80 that reaches the nucleus (Zeng et al. 2009). ERBB4 also binds the E3 ubiquitin ligase MDM2, and inhibitor of p53 (Arasada et al. 2005). Other proteins that bind to ERBB4 intracellular domain have been identified by co-immunoprecipitation and mass spectrometry (Gilmore-Hebert et al., 2010), and include transcriptional co-repressor TRIM28/KAP1, which promotes chromatin compaction. DNA damage signaling through ATM releases TRIM28-associated heterochromatinization. Interactions of ERBB4 with TRIM28 and MDM2 may be important for integration of growth factor responses and DNA damage responses. In human breast cancer cell lines, ERBB4 activation enhances anchorage-independent colony formation in soft agar but inhibits cell growth in a monolayer culture. Different ERBB4 ligands induce different gene expression changes in breast cancer cell lines. Some of the genes induced in response to ERBB4 signaling in breast cancer cell lines are RAB2, EPS15R and GATA4. It is not known if these gene are direct transcriptional targets of ERBB4 (Amin et al. 2004). Transcriptome and ChIP-seq comparisons of full-length and intracellular domain isoforms in isogenic MCF10A mammary cell background have revealed the diversification of ERBB4 signaling engendered by alternative splicing and cleavage (Wali et al., 2014). ERBB4 broadly affected protease expression, cholesterol biosynthesis, HIF1-alpha signaling, and HIPPO signaling pathways, and other pathways were differentially activated by CYT1 and CYT2 isoforms. For example, CYT1 promoted expression of transcription factors TWIST1 and SNAIL1 that promote epithelial-mesenchymal transition. HIF1-alpha and HIPPO signaling are mediated, respectively, by binding of ERBB4 to HIF1-alpha and to YAP (Paatero et al., 2012, Komuro et al., 2003). ERBB4 increases activity of the transcription factor SREBF2, resulting in increased expression of SREBF2-target genes involved in cholesterol biosynthesis. The mechanism is not known and may involve facilitation of SREBF2 cleavage through ERBB4-mediated PI3K signaling (Haskins et al. 2016). In some contexts, ERBB4 promotes growth suppression or apoptosis (Penington et al., 2002). Activation of ERBB4 in breast cancer cell lines leads to JNK dependent increase in BRCA1 mRNA level and mitotic cell cycle delay, but the exact mechanism has not been elucidated (Muraoka Cook et al. 2006). The nature of growth responses may be connected with the spliced isoforms expressed. In comparisons of CYT1 vs CYT2 (full-length and ICD) expression in mammary cells, CYT1 was a weaker growth inducer, associated with attenuated MAPK signaling relative to CYT2 (Wali et al., 2014). ERBB4 s80 is also able to translocate to the mitochondrial matrix, presumably when its nuclear translocation is inhibited. Once in the mitochondrion, the BH3 domain of ERBB4, characteristic of BCL2 family members, may enable it to act as a pro apoptotic factor (Naresh et al. 2006). ERBB4 plays important roles in the developing and adult nervous system. Erbb4 deficiency in somatostatin-expressing neurons of the thalamic reticular nucleus alters behaviors dependent on sensory selection (Ahrens et al. 2015). NRG1-activated ERBB4 signaling enhances AMPA receptor responses through PKC-dependent AMPA receptor exocytosis. This results in an increased excitatory input to parvalbumin-expressing inhibitory neurons in the visual cortex and regulates visual cortical plasticity (Sun et al. 2016). NRG1-activated ERBB4 signaling is involved in GABAergic activity in amygdala which mediates fear conditioning (fear memory) (Lu et al. 2014). Conditional Erbb4 deletion from fast-spiking interneurons, chandelier and basket cells of the cerebral cortex leads to synaptic defects associated with increased locomotor activity and abnormal emotional, social and cognitive function that can be linked to some of the schizophrenia features. The level of GAD1 (GAD67) protein is reduced in the cortex of conditional Erbb4 mutants. GAD1 is a GABA synthesizing enzyme. Cortical mRNA levels of GAD67 are consistently decreased in schizophrenia (Del Pino et al. 2014). Erbb4 is expressed in the GABAergic neurons of the bed nucleus stria terminalis, a part of the extended amygdala. Inhibition of NRG1-triggered ERBB4 signaling induces anxiety-like behavior, which depends on GABAergic neurotransmission. NRG1-ERBB4 signaling stimulates presynaptic GABA release, but the exact mechanism is not known (Geng et al. 2016). NRG1 protects cortical interneurons against ischemic brain injury through ERBB4-mediated increase in GABAergic transmission (Guan et al. 2015). NRG2-activated ERBB4 can reduce the duration of GABAergic transmission by binding to GABA receptors at the postsynaptic membrane via their GABRA1 subunit and promoting endocytosis of GABA receptors (Mitchell et al. 2013). NRG1 promotes synchronization of prefrontal cortex interneurons in an ERBB4 dependent manner (Hou et al. 2014). NRG1-ERBB4 signaling protects neurons from the cell death induced by a mutant form of the amyloid precursor protein (APP) (Woo et al. 2012). Clinical relevance of ERBB4 has been identified in several contexts. In cancer, putative and validated gain-of-function mutations or gene amplification that may be drivers have been identified at modest frequencies, and may also contribute to resistance to EGFR and ERBB2-targeted therapies. This is noteworthy as ERBB4 kinase activity is inhibited by pan-ERBB tyrosine kinase inhibitors, including lapatinib, which is approved by the US FDA. The reduced prevalence relative to EGFR and ERBB2 in cancer may reflect more restricted expression of ERBB4, or differential signaling, as specific ERBB4 isoforms have been linked to growth inhibition or apoptosis in experimental systems. ERBB2/ERBB4 heterodimers protect cardiomyocytes, so reduced activity of ERBB4 in patients treated with the ERBB2-targeted therapeutic antibody trastuzumab may contribute to the cardiotoxicity of this agent when used in combination with (cardiotoxic) anthracyclines. With the importance of ERBB4 in developing and adult nervous system, NRG1 and/or ERBB4 polymorphisms, splicing aberrations and mutations have been linked to nervous system disorders including schizophrenia and amyotrophic lateral sclerosis, although these findings are not yet definitive."
BMGC_PW0468,BMG_PW2758,,,"Dendritic cells (DCs) take up and process exogenous particulate or cell-associated antigens such as microbes or tumor cells for MHC-I cross-presentation. Particulate antigens have been reported to be more efficiently cross-presented than soluble antigens by DCs (Khor et al. 2008). Particulate antigens are internalized by phagosomes. There are two established models that explain the mechanism by which exogenous particulate antigens are presented through MHC I; the cytosolic pathway where internalized antigens are somehow translocated from phagosomes into cytosol for proteasomal degradation and the vacuolar pathway (Lin et al. 2008, Amigorena et al. 2010)."
BMGC_PW0469,BMG_PW2759,,,"The other TAP-dependent cross-presentation mechanism in phagocytes is the endoplasmic reticulum (ER)-phagosome model. Desjardins proposed that ER is recruited to the cell surface, where it fuses with the plasma membrane, underneath phagocytic cups, to supply membrane for the formation of nascent phagosomes (Gagnon et al. 2002). Three independent studies simultaneously showed that ER contributes to the vast majority of phagosome membrane (Guermonprez et al. 2003, Houde et al. 2003, Ackerman et al. 2003). The composition of early phagosome membrane contains ER-resident proteins, the components required for cross-presentation. This model is similar to the phagosome-to-cytosol model in that Ag is translocated to cytosol for proteasomal degradation, but differs in that antigenic peptides are translocated back into the phagosome (instead of ER) for peptide:MHC-I complexes. ER fusion with phagosome introduces molecules that are involved in Ag transport to cytosol (Sec61) and proteasome-generated peptides back into the phagosome (TAP) for loading onto MHC-I. Although the ER-phagosome pathway is controversial, the concept remains attractive as it explains how peptide-receptive MHC-I molecules could intersect with a relatively high concentration of exogenous antigens, presumably a crucial prerequisite for efficient cross-presentation (Basha et al. 2008)."
BMGC_PW0470,BMG_PW2760,,,"Some antigens are cross-presented through a vacuolar mechanism that involves generation of antigenic peptides and their loading on to MHC-I molecules within the endosomal compartment in a proteasome and TAP-independent manner. Antigens within the endosome are processed by cathepsin S and other proteases into antigenic peptides. Loading of these peptides onto MHC-I molecules occurs directly within early and late endosomal compartments. Why certain antigens are cross-presented exclusively by the cytosolic pathway while others use the vacuolar pathway is unknown. It may be because some epitopes cannot be generated by endosomal proteolysis, or are completely destroyed. Alternatively, the physical form of the antigen may influence its accessibility to the endosomal or vacuolar pathways (Shen et al. 2004)."
BMGC_PW0471,BMG_PW2761,,,"Exogenous soluble antigens are cross-presented by dendritic cells, albeit with lower efficiency than for particulate substrates. Soluble antigens destined for cross-presentation are taken up by distinct endocytosis mechanisms which route them into stable early endosomes and then to the cytoplasm for proteasomal degradation and peptide loading."
BMGC_PW0472,BMG_PW2762,,,"Carbon dioxide (CO2) in plasma is hydrated to yield protons (H+) and bicarbonate (HCO3-) by carbonic anhydrase IV (CA4) located on the apical plasma membranes of endothelial cells. Plasma CO2 is also taken up by erythrocytes via AQP1 and RhAG. Within erythrocytes CA1 and, predominantly, CA2 hydrate CO2 to HCO3- and protons (reviewed in Geers & Gros 2000, Jensen 2004, Boron 2010). The HCO3- is transferred out of the erythrocyte by the band 3 anion exchange protein (AE1, SLC4A1) which cotransports a chloride ion (Cl-) into the erythrocyte. Also within the erythrocyte, CO2 combines with the N-terminal alpha amino groups of HbA to form carbamates while protons bind histidine residues in HbA. The net result is the Bohr effect, a conformational change in HbA that reduces its affinity for O2 and hence assists the delivery of O2 to tissues."
BMGC_PW0473,BMG_PW2763,,,"Methionine salvage is a sequential pathway of six reactions that create methionine from 5'-methylthioadenosine (MTA) which is a byproduct of polyamine biosynthesis in nearly all organisms. The process happens completely in the cytosol. It is important in humans for recycling of sulphur that has to be assimilated using energy. (Pirkov et al, 2008; Albers, 2009)"
BMGC_PW0474,BMG_PW2764,,,"Erythrocytes circulating through the capillaries of the lung must exchange carbon dioxide (CO2) for oxygen (O2) during their short (0.5-1 sec.) transit time in pulmonary tissue (Reviewed in Jensen 2004, Esbaugh and Tufts 2006, Boron 2010). CO2 bound as carbamate to the N-terminus of hemoglobin and protons (H+) bound to histidine residues in hemoglobin are released as hemoglobin (HbA) binds O2. Bicarbonate (HCO3-) present in plasma is taken up by erythrocytes via the band3 anion exchanger (AE1, SLC4A1) and combined with H+ by carbonic anhydrases I and II (CA1/CA2) to yield water and CO2 (Reviewed by Esbaugh and Tufts 2006). CO2 is passively transported out of the erythrocyte by AQP1 and RhAG. HCO3- in plasma is also directly dehydrated by extracellular carbonic anhydrase IV (CA4) present on endothelial cells lining the capillaries in the lung."
BMGC_PW0475,BMG_PW2765,,,"All ERBB2 heterodimers, ERBB2:EGFR, ERBB2:ERBB3 and ERBB2:ERBB4, are able to activate RAF/MAP kinase cascade by recruiting SHC1 (Pinkas-Kramarski et al. 1996, Sepp-Lorenzino et al. 1996) to phosphorylated C-tail tyrosine residues in either EGFR (Y1148 and Y1173), ERBB2 (Y1196, Y1221, Y1222 and Y1248), ERBB3 (Y1328) or ERBB4 (Y1188 and Y1242 in JM-A CYT1 isoform, Y1178 and Y1232 in JM-B CYT1 isoform, Y1172 and Y1226 in JM-A CYT2 isoform). SHC1 recruitment is followed by phosphorylation (Segatto et al. 1993, Soler et al. 1994), and the phosphorylated SHC1 recruits GRB2:SOS1 complex (Xie et al. 1995), which leads to SOS1-mediated guanyl-nucleotide exchange on RAS (Xie et al. 1995) and downstream activation of RAF and MAP kinases."
BMGC_PW0476,BMG_PW2766,,,"The CYT1 isoforms of ERBB4 possess a C-tail tyrosine residue that, upon trans-autophosphorylation, serves as a docking site for the p85 alpha subunit of PI3K - PIK3R1 (Kaushansky et al. 2008, Cohen et al. 1996). Binding of PIK3R1 to CYT1 isoforms of ERBB4 is followed by recruitment of the p110 catalytic subunit of PI3K (PIK3CA), leading to assembly of an active PI3K complex that converts PIP2 to PIP3 and activates AKT signaling (Kainulainen et al. 2000)."
BMGC_PW0477,BMG_PW2767,,,"All splicing isoforms of ERBB4 possess two tyrosine residues in the C-tail that serve as docking sites for SHC1 (Kaushansky et al. 2008, Pinkas-Kramarski et al. 1996, Cohen et al. 1996). Once bound to ERBB4, SHC1 becomes phosphorylated on tyrosine residues by the tyrosine kinase activity of ERBB4, which enables it to recruit the complex of GRB2 and SOS1, resulting in the guanyl-nucleotide exchange on RAS and activation of RAF and MAP kinase cascade (Kainulainen et al. 2000)."
BMGC_PW0478,BMG_PW2768,,,"Activation of PLCG1 signaling is observed only in the presence of ERBB2:EGFR heterodimers, with PLCG1 binding to phosphorylated tyrosine Y992 and Y1173 in the C-tail of EGFR (Chattopadhyay et al. 1999), and potentially Y1023 in the C-tail of ERBB2 (Fazioli et al. 1991, Cohen et al. 1996)."
BMGC_PW0479,BMG_PW2769,,,"Besides signaling as a transmembrane receptor, ligand activated homodimers of ERBB4 JM-A isoforms (ERBB4 JM-A CYT1 and ERBB4 JM-A CYT2) undergo proteolytic cleavage by ADAM17 (TACE) in the juxtamembrane region, resulting in shedding of the extracellular domain and formation of an 80 kDa membrane bound ERBB4 fragment known as ERBB4 m80 (Rio et al. 2000, Cheng et al. 2003). ERBB4 m80 undergoes further proteolytic cleavage, mediated by the gamma-secretase complex, which releases the soluble 80 kDa ERBB4 intracellular domain, known as ERBB4 s80 or E4ICD, into the cytosol (Ni et al. 2001). ERBB4 s80 is able to translocate to the nucleus, promote nuclear translocation of various transcription factors, and act as a transcription co-factor. In neuronal precursors, ERBB4 s80 binds the complex of TAB and NCOR1, helps to move the complex into the nucleus, and is a co-factor of TAB:NCOR1-mediated inhibition of expression of astrocyte differentiation genes GFAP and S100B (Sardi et al. 2006). In mammary cells, ERBB4 s80 recruits STAT5A transcription factor in the cytosol, shuttles it to the nucleus, and acts as the STAT5A co-factor in binding to and promoting transcription from the beta-casein (CSN2) promoter, and may be involved in the regulation of other lactation-related genes (Williams et al. 2004, Muraoka-Cook et al. 2008). ERBB4 s80 was also shown to bind activated estrogen receptor in the nucleus and act as its transcriptional co-factor in promoting transcription of some estrogen-regulated genes, such as progesterone receptor gene NR3C3 and CXCL12 i.e. SDF1 (Zhu et al. 2006). ERBB4s80 may inhibit transcription of telomerase reverse transcriptase (TERT) by increasing methylation of the TERT gene promoter through an unknown mechanism (Ishibashi et al. 2012). The C-tail of ERBB4 possesses several WW-domain binding motifs (three in CYT1 isoform and two in CYT2 isoform), which enable interaction of ERBB4 with WW-domain containing proteins. ERBB4 s80, through WW-domain binding motifs, interacts with YAP1 transcription factor, a known proto-oncogene, and may be a co-regulator of YAP1-mediated transcription (Komuro et al. 2003, Omerovic et al. 2004). The tumor suppressor WWOX, another WW-domain containing protein, competes with YAP1 in binding to ERBB4 s80 and prevents translocation of ERBB4 s80 to the nucleus (Aqeilan et al. 2005). ERBB4 s80 is also able to translocate to the mitochondrial matrix, presumably when its nuclear translocation is inhibited. Once in the mitochondrion, the BH3 domain of ERBB4, characteristic of BCL2 family members, may enable it to act as a pro-apoptotic factor (Naresh et al. 2006)."
BMGC_PW0480,BMG_PW2770,,,"WW-domain binding motifs in the C-tail of ERBB4 play an important role in the downregulation of ERBB4 receptor signaling, enabling the interaction of intact ERBB4, ERBB4 m80 and ERBB4 s80 with NEDD4 family of E3 ubiquitin ligases WWP1 and ITCH. The interaction of WWP1 and ITCH with intact ERBB4 is independent of receptor activation and autophosphorylation. Binding of WWP1 and ITCH ubiquitin ligases leads to ubiquitination of ERBB4 and its cleavage products, and subsequent degradation through both proteasomal and lysosomal routes (Omerovic et al. 2007, Feng et al. 2009). In addition, the s80 cleavage product of ERBB4 JM-A CYT-1 isoform is the target of NEDD4 ubiquitin ligase. NEDD4 binds ERBB4 JM-A CYT-1 s80 (ERBB4jmAcyt1s80) through its PIK3R1 interaction site and mediates ERBB4jmAcyt1s80 ubiquitination, thereby decreasing the amount of ERBB4jmAcyt1s80 that reaches the nucleus (Zeng et al. 2009)."
BMGC_PW0481,BMG_PW2771,,,"Signaling by AKT is one of the key outcomes of receptor tyrosine kinase (RTK) activation. AKT is activated by the cellular second messenger PIP3, a phospholipid that is generated by PI3K. In ustimulated cells, PI3K class IA enzymes reside in the cytosol as inactive heterodimers composed of p85 regulatory subunit and p110 catalytic subunit. In this complex, p85 stabilizes p110 while inhibiting its catalytic activity. Upon binding of extracellular ligands to RTKs, receptors dimerize and undergo autophosphorylation. The regulatory subunit of PI3K, p85, is recruited to phosphorylated cytosolic RTK domains either directly or indirectly, through adaptor proteins, leading to a conformational change in the PI3K IA heterodimer that relieves inhibition of the p110 catalytic subunit. Activated PI3K IA phosphorylates PIP2, converting it to PIP3; this reaction is negatively regulated by PTEN phosphatase. PIP3 recruits AKT to the plasma membrane, allowing TORC2 to phosphorylate a conserved serine residue of AKT. Phosphorylation of this serine induces a conformation change in AKT, exposing a conserved threonine residue that is then phosphorylated by PDPK1 (PDK1). Phosphorylation of both the threonine and the serine residue is required to fully activate AKT. The active AKT then dissociates from PIP3 and phosphorylates a number of cytosolic and nuclear proteins that play important roles in cell survival and metabolism. For a recent review of AKT signaling, please refer to Manning and Cantley, 2007."
BMGC_PW0482,BMG_PW2772,,,"Developmental biology seeks to understand the array of processes by which a fertilized egg gives rise to the diverse tissues of the adult body. Examples of several developmental processes have been annotated here. In the early embryo, transcriptional regulation of pluripotent stem cells, gastrulation (including NODAL signaling), and activation of HOX genes during differentiation are annotated. Annotations of later, more specialized processes include nervous system development, cardiogenesis, aspects of the roles of cell adhesion molecules in axonal guidance and myogenesis, transcriptional regulation in pancreatic beta cells, adipogenesis, transcriptional regulation of granulopoeisis, transcriptional regulation of testis differentiation, LGI-ADAM interactions, and keratinization. Transitions between cell types and cell states in developmental and differentiation processes are annotated as developmental cell lineages."
BMGC_PW0483,BMG_PW2773,,,"Sprouty was initially characterized as a negative regulator of FGFR signaling in Drosophila. Human cells contain four genes encoding Sprouty proteins, of which Spry2 is the best studied and most widely expressed. Spry proteins modulate the duration and extent of signaling through the MAPK cascade after FGF stimulation, although the mechanism appears to depend on the particular biological context. Some studies have suggested that Sprouty binds to GRB2 and interferes with the recruitment of GRB2-SOS1 to the receptor, while others have shown that Sprouty interferes with the MAPK cascade at the level of RAF activation. In addition to modulating the MAPK pathway in response to FGF stimulation, Sprouty itself appears to be subject to complex post-translational modification that regulates its activity and stability."
BMGC_PW0484,BMG_PW2774,,,"ATP sensitive K+ channels couple intracellular metabolism with membrane excitability. These channels are inhibited by ATP so are open in low metabolic states and close in high metabolic states, resulting in membrane depolarization triggering responses such as insulin secretion, modulation of vascular smooth muscle and cardioprotection. The channel comprises four Kir6.x subunits and four regulatory sulphonylurea receptors (SUR) (Akrouh et al, 2009)."
BMGC_PW0485,BMG_PW2775,,,Activation of Kir 3 channels occurs after binding of G beta gamma subunits of GPCR. Activation of Kir3/GIRK leads to K+ efflux. The dissociation of GPCR into G alpha and G beta gamma subunits is activated by the activation of GABA B receptor by GABA binding.
BMGC_PW0486,BMG_PW2776,,,"Ca2+ activated potassium channels are expressed in neuronal and non-neuronal tissue such as smooth muscle, epithelial cell and sensory cells. Ca2+ activated potassium channels are activated when the Ca2+ ion concentration increased, The efflux of K+ via these channels leads to repolarization/hyperpolarization of the membrane potential which limits the Ca2+ influx though voltage activated Ca2+ channels (VGCC) thereby regulating the influx of Ca2+ flow via VGCC."
BMGC_PW0487,BMG_PW2777,,,"Classical Kir channels are inwardly rectifying K+ channels with strong inwardly rectifying currents that contribute to highly negative resting membrane potential, prolonged action potential plateau and rapid repolarization in the final stage of action potential. Classical Kir channels are found in various cells such as cardiac myocytes, purkinje fibers, atrial and ventricular tissues. Rectification is caused by intracellular Mg2+ ions and polyamines."
BMGC_PW0488,BMG_PW2778,,,"Inwardly rectifying G protein activated K+ channels (GIRK) are tetrameric assemblies of Ki3 3 family subunits (Kir 3.1, 3.2 3.3 and 3.4). The activation of G protein coupled receptor by ligand results in the liberation of G alpha and G beta gamma subunits. Gbeta gamma subunits interact and activate GIRK channels."
BMGC_PW0489,BMG_PW2780,,,"Inwardly rectifying K+ channels (Kir channels) show an inward rather than outward (like the voltage gated K+ channels) flow of K+ thereby contributing to maintenance of resting membrane potential and regulation of action potential in excitable tissue. Kir channels are found in a variety of cell types such as cardiac myocytes, neurons, blood cells, osteoblasts, glial cells, epithelial cells, and oocytes. Kir channels can be functionally divided into ATP sensitive K+ channels (Kir 6.1 and Kir 6.2), classical kir channels (Kir 2.1, 2.2, 2.3, 2.4, 5.1) G protein gated K+ channels (Kir 3.1, 3.2, 3.3, 3.4) and K+ transport channels (Kir1.1, 7.1, 4.2, 4.1)."
BMGC_PW0490,BMG_PW2781,,,"Inwardly rectifying potassium transport are tetrameric channels that are found in kidney in the nephron. Kir 1.1 works as a homotetramer, however, Kir 4.1 and 5.1 work as heterotetramers. These channels transport K+ from cytosol to the lumen of the tubules."
BMGC_PW0491,BMG_PW2782,,,"Potassium channels are tetrameric ion channels that are widely distributed and are found in all cell types. Potassium channels control resting membrane potential in neurons, contribute to regulation of action potentials in cardiac muscle and help release of insulin form pancreatic beta cells. Broadly K+ channels are classified into voltage gated K+ channels, Hyperpolarization activated cyclic nucleotide gated K+ channels (HCN), Tandem pore domain K+ channels, Ca2+ activated K+ channels and inwardly rectifying K+ channels."
BMGC_PW0492,BMG_PW2783,,,"Voltage-gated K+ channels (Kv) determine the excitability of heart, brain and skeletal muscle cells. Kv form octameric channel with alpha subunits that forms the pore of the channel and associated beta subunits. The alpha subunits associate with beta subunits with a stoichiometry of alpha4beta4.The alpha subunits have been classified into 12 families, 1-12 with several representatives from each family. Members of Kv 1-4 form both homotetramers and heterotetramers, however, members of Kv 5-12 form functional heterotetramers. Kv's are expressed in the axon, at axon nodes, somatodendritic sites and axon termini."
BMGC_PW0493,BMG_PW2784,,,"Tandem pore domain K+ channels (K2p) produce leak K+ current which stabilizes negative membrane potential and counter balances depolarization. These channels are regulated by voltage independent mechanisms such as membrane stretch, pH, temperature. Tandem pore domain K+ channels have been classified into six subfamilies; tandem pore domains in weak rectifying K+ channel (TWIK), TWIK-related K+ channel (TREK), TWIK-related acid-sensitive K+ channel (TASK), TWIK-related alkaline pH-activated K+ channel (TALK), tandem pore domain halothane-inhibted K+ channel (THIK), TWIK-releated spinal cord K+ channel)."
BMGC_PW0494,BMG_PW2787,,,"TASK 1 and 3 are closely related both structurally and functionally. TASK1 and TASK3 are activated by extracellular acidification and inhibited by decrease in pH. TASK 1 and Task 3 form functional homodimers and heterodimers, however the biophysical properties of TAS1 and TASK3 heteromers are different form parent subunit properties."
BMGC_PW0495,BMG_PW2790,,,"TREK1 and TREK 2 are activated by physiochemical changes like stretch, convex deformation of the plasma membrane, depolarization, heat and intracellular acidosis. Polyunsaturated fatty acids (PUFA) including arachidonic acid open TREK channels."
BMGC_PW0496,BMG_PW2791,,,"A series of receptor signaling pathways potentially govern chemical communication between sperm and egg, chemotactically guiding incoming sperm towards the oocyte. Though several substances are confirmed as sperm chemoattractant, progesterone (P) seems to be the best chemoattractant candidate for human sperm. Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH regulated, calcium selective ion channel, potassium channel KSper (Slo3), and Hv1, the voltage gated proton channel are involved in regulation of sperm hyperactivated motility. While progesterone, secreted by ovulated cumulus oophorus, may act as a chemoattractant for sperm cells over the short distances, a major determinant of sperm guidance over long distances in the mammalian female reproductive tract is rheotaxis."
BMGC_PW0497,BMG_PW2793,,,"Heterodimers of ERBB2 and ERBB3 are able to bind GRB7 (Fiddes et al. 1998) through phosphorylated tyrosine residues in the C-tail of ERBB3 (Y1199 and Y1262) (Fiddes et al. 1998), but the exact downstream signaling of this complex has not been elucidated. GRB7 can recruit SHC1 to the active ERBB2 complex, and contributes to ERBB2 signaling-induced RAS activation, which promotes cellular proliferation, but the exact mechanism has not been elucidated (Pradip et al. 2013). In addition, GRB7 can be phosphorylated by the integrin-activated PTK2 (FAK), leading to VAV2-dependent activation of RAC1 and promotion of cell migration. The exact mechanistic details of GRB7-induced RAC1 activation are not known (Pradip et al. 2013)."
BMGC_PW0498,BMG_PW2795,,,"Level of plasma membrane ERBB3 is regulated by E3 ubiquitin ligase RNF41 (also known as NRDP1), which binds and ubiquitinates both inactive and activated ERBB3, targeting it for degradation (Cao et al. 2007). RNF41 is subject to self-ubiquitination which keeps its levels low when ERBB3 is not stimulated, and preserves ERBB3 expression on the cell surface (Qiu et al. 2002). Self-ubiquitination of RNF41 is reversible, through the action of ubiquitin protease USP8, an enzyme stabilized by AKT-mediated phosphorylation. Therefore, activation of AKT by ERBB2:ERBB3 signaling leads to phosphorylation of USP8 (Cao et al. 2007), which increases level of RNF41 through deubiquitination, and results in degradation of activated ERBB3 (Cao et al. 2007) - a negative feedback loop of ERBB3 signaling. Downregulation of EGFR and ERBB4 signaling is explained in pathways Signaling by EGFR and Signaling by ERBB4."
BMGC_PW0499,BMG_PW2798,,,"Iron-sulfur (Fe-S) proteins are localized in the cytosol, nucleus, and mitochondria of mammalian cells (reviewed in Stemmler et al. 2010, Rouault 2012, Bandyopadhyay et al. 2008, Lill 2009, Lill et al. 2012). Fe-S protein biogenesis in the mitochondrial matrix involves the iron-sulfur cluster (ISC) assembly machinery. Ferrous iron is transported across the inner mitochondrial membrane into the mitochondrial matrix by Mitoferrin-1 (SLC25A37) and Mitoferrin-2 (SLC25A28). (Mitoferrin-1 is enriched in erythroid cells while Mitoferrin-2 is ubiquitous.) Frataxin binds ferrous iron in the mitochondrial matrix. The cysteine desulfurase NFS1 in a subcomplex with ISD11 provides the sulfur by converting cyteine into alanine and forming a persulfide which is used for cluster formation on ISCU, the scaffold protein. Interaction between NFS1 and ISD11 is necessary for desulfurase activity. Frataxin binds to a complex containing NFS1, ISD11, and ISCU and is proposed to function as an iron donor to ISCU or as an allosteric switch that activates sulfur transfer and Fe-S cluster assembly (Tsai and Barondeau 2010). Cluster formation also involves the electron transfer chain ferredoxin reductase and ferredoxin. ISCU initially forms clusters containing 2 iron atoms and 2 sulfur atoms ([2Fe-2S] clusters). They are released by the function of HSP70-HSC20 chaperones and the monothiol glutaredoxin GLRX5 and used for assembly of [2Fe-2S] proteins. Assembly of larger clusters such as [4Fe-4S] clusters may involve the function of ISCA1, ISCA2, and IBA57. The clusters are transferred to apo-enzymes such as the respiratory complexes, aconitase, and lipoate synthase through dedicated targeting factors such as IND1, NFU1, and BOLA3."
BMGC_PW0500,BMG_PW2800,,,"As inferred from mouse, RORA binds ROR elements (ROREs) in DNA and recruits the coactivators PPARGC1A (PGC-1alpha) and p300 (EP300, a histone acetylase) to activate transcription."
BMGC_PW0501,BMG_PW2801,,,"As inferred from mouse, BMAL1:CLOCK (ARNTL:CLOCK) and BMAL1:NPAS2 (ARNTL:NPAS2) heterodimers bind to sequence elements (E boxes) in the promoters of target genes and enhance transcription (Gekakis et al. 1998, reviewed in Munoz and Baler 2003)."
BMGC_PW0502,BMG_PW2802,,"The ATP-binding cassette (ABC) transporters form one of the largest known protein families, and are widespread in bacteria, archaea, and eukaryotes. They couple ATP hydrolysis to active transport of a wide variety of substrates such as ions, sugars, lipids, sterols, peptides, proteins, and drugs. The structure of a prokaryotic ABC transporter usually consists of three components; typically two integral membrane proteins each having six transmembrane segments, two peripheral proteins that bind and hydrolyze ATP, and a periplasmic (or lipoprotein) substrate-binding protein. Many of the genes for the three components form operons as in fact observed in many bacterial and archaeal genomes. On the other hand, in a typical eukaryotic ABC transporter, the membrane spanning protein and the ATP-binding protein are fused, forming a multi-domain protein with the membrane-spanning domain (MSD) and the nucleotide-binding domain (NBD).",Mammalian ABC transporters are usually found on the plasma membrane and on organelles such as the ER and peroxisome but a small number are also located on the mitochondria. Here they are thought to play roles in heme biosynthesis and iron-sulphur cluster synthesis (Burke & Ardehali 2007).
BMGC_PW0503,BMG_PW2803,,,"A defined subset of the ABC transporter superfamily, the ABCA transporters, are highly expressed in monocytes and macrophages and are regulated by cholesterol flux which may indicate their role in in chronic inflammatory diseases (Schmitz and Kaminski 2001, Schmitz et al. 2000). Some D and G members of the ABC transporter family are also important in lipid transport (Voloshyna & Reiss 2011, Morita & Imanaka 2012, Morita et al. 2011)."
BMGC_PW0504,BMG_PW2804,,,"Activation of non- excitable cells involves the agonist-induced elevation of cytosolic Ca2+, an essential process for platelet activation. It occurs through Ca2+ release from intracellular stores and Ca2+ entry through the plasma membrane. Ca2+ store release involves phospholipase C (PLC)-mediated production of inositol-1,4,5-trisphosphate (IP3), which in turn stimulates IP3 receptor channels to release Ca2+ from intracellular stores. This is followed by Ca2+ entry into the cell through plasma membrane calcium channels, a process referred to as store-operated calcium entry (SOCE). Stromal interaction molecule 1 (STIM1), a Ca2+ sensor molecule in intracellular stores, and the four transmembrane channel protein Orai1 are the key players in platelet SOCE. Other major Ca2+ entry mechanisms are mediated by the direct receptor-operated calcium (ROC) channel, P2X1 and transient receptor potential channels (TRPCs)."
BMGC_PW0505,BMG_PW2806,,,Puma is transactivated in a p53-dependent manner and by E2F1. Activated Puma is translocated to mitochondria.
BMGC_PW0506,BMG_PW2807,,,"Human amine oxidases (AO) catalyze the oxidative deamination of biogenic amines (neurotransmitters such as serotonin, noradrenaline, the hormone adrenaline and polyamines such as the spermines) and xenobiotic amines (exogenous dietary tyramine and phenylethylamine). The basic reaction is the oxidative cleavage of the alpha-H to form an imine product with the concomitant reduction of a FAD cofactor. The imine product then hydrolyses to an aldehyde and ammonia (or amine for secondary and tertiary amine substrates). Reduced FAD is reoxidized to form hydrogen peroxide to complete the catalytic cycle. The reaction can be summarized as RCH2NH2 + H2O + O2 = RCHO + NH3 + H2O2 The resultant hydrogen peroxide is the source of the most toxic free radical, the hydroxyl radical (.OH). This free radical is produced in the Fenton reaction with the use of ferrous (Fe2+) iron."
BMGC_PW0507,BMG_PW2809,,,"DNA fragmentation in response to apoptotic signals is achieved, in part, through the activity of apoptotic nucleases, termed DNA fragmentation factor (DFF) or caspase-activated DNase (CAD) (reviewed in Widlak and Garrard, 2005). In non-apoptotic cells, DFF is a nuclear heterodimer consisting of a 45 kD chaperone and inhibitor subunit (DFF45)/inhibitor of CAD (ICAD-L)] and a 40 kD nuclease subunit (DFF40/CAD)( Liu et al. 1997, 1998; Enari et al. 1998). During apoptosis, activated caspase-3 or -7 cleave DFF45/ICAD releasing active DFF40/CAD nuclease. The activity of DFF is tightly controlled at multiple stages. During translation, DFF45/ICAD, Hsp70, and Hsp40 proteins play a role in insuring the appropriate folding of DFF40 during translation(Sakahira and Nagata, 2002). The nuclease activity of DFF40 is enhanced by the chromosomal proteins histone H1, Topoisomerase II and HMGB1/2(Widlak et al., 2000). In addition, the inhibitors (DFF45/35; ICAD-S/L) are produced in stoichiometric excess (Widlak et al., 2003)."
BMGC_PW0508,BMG_PW2810,,,"Caspase-8 is synthesized as zymogen (procaspase-8) and is formed from procaspase-8 as a cleavage product. However, the cleavage itself appears not to be sufficient for the formation of an active caspase-8. Only the coordinated dimerization and cleavage of the zymogen produce efficient activation in vitro and apoptosis in cellular systems [Boatright KM and Salvesen GS 2003; Keller N et al 2010; Oberst A et al 2010]. The caspase-8 zymogens are present in the cells as inactive monomers, which are recruited to the death-inducing signaling complex (DISC) by homophilic interactions with the DED domain of FADD. The monomeric zymogens undergo dimerization and the subsequent conformational changes at the receptor complex, which results in the formation of catalytically active form of procaspase-8.[Boatright KM et al 2003; Donepudi M et al 2003; Keller N et al 2010; Oberst A et al 2010]."
BMGC_PW0509,BMG_PW2811,,,"Factor VII, the protease that initiates the normal blood clotting cascade, circulates in the blood in both its proenzyme (factor VII) and its activated (factor VIIa) forms. No clotting occurs, however, because neither form of the protein has any catalytic activity when free in solution. Blood clotting is normally initiated when tissue factor (TF), an intrinsic plasma membrane protein, is exposed to the blood by injury to the wall of a blood vessel. TF is then able to bind factor VIIa from plasma, and possibly also factor VII, to form complexes capable of catalyzing the conversion of factor X, from plasma, into its activated form, factor Xa. Factor Xa catalyzes the conversion of additional factor VII molecules to their activated form, increasing the amount of tissue factor:factor VIIa complex available at the site of injury, accelerating the generation of factor Xa, and allowing the activation of factor IXa as well. This process is self-limiting because as levels of factor Xa increase, tissue factor:factor VIIa complexes become trapped in the form of catalytically inactive heterotetramers with factor Xa and the protein TFPI (tissue pathway factor inhibitor). At this point the intinsic pathway, as an independent source of activated factor X, is thought to become critical for the continuation of clot formation (Broze 1995; Mann et al. 2003). The nature of the initial tissue factor:factor VII complexes formed is controversial. One model, building on the observation that the complex of factor VII and TF has low but measurable proteolytic activity on factor X, suggests that this complex begins the activation of factor X, and that as factor VIIa accumulates, tissue factor:factor VIIa complexes also form, accelerating the process (Nemerson 1988). A second model, building on the observation that normal plasma contains low levels of activated factor VII constitutively, suggests that complexes with factor VIIa form immediately at the onset of clotting (Rapaport and Rao 1995). The two models are not mutually exclusive, and in any event, the central roles of tissue factor and factor VIIa in generating an initial supply of factors IXa and Xa, and the self-limiting nature of the process due to the action of TFPI, are all well-established."
BMGC_PW0510,BMG_PW2812,,,"The intrinsic pathway of blood clotting connects interactions among kininogen (high molecular weight kininogen, HK), prekallikrein (PK), and factor XII to the activation of clotting factor X by a series of reactions that is independent of the extrinsic pathway and that is not subject to inhibition by TFPI. It is thus essential for the prolongation of the clotting cascade: while the reactions of the extrinsic pathway appear to be sufficient to initiate clot formation, those of the intrinsic pathway are required to maintain it (Broze 1995; Davie et al. 1991; Monroe et al. 2002). The intrinsic pathway can be divided into three parts: 1) reactions involving interactions of kininogen, prekallikrein, and factor XII, leading to the activation of factor XII, 2) reactions involving factor XI, factor IX, factor VIII, and von Willebrand factor (vWF) leading to the activation of factors VIII and IX, and 3) reactions that inactivate factor XIIa and kallikrein. Kininogen, prekallikrein, and factor XII were first identified as proteins needed for the rapid formation of clots when whole blood is exposed to negatively charged surfaces in vitro. Early studies in vitro identified several possible sets of interactions, in which small quantities of one or more of these proteins 'autoactivate' and then catalyze the formation of larger quantities of activated factors. Subsequent work, however, suggests that these factors form complexes on endothelial cell surfaces mediated by C1q binding protein (C1q bp), that the first activation event is the cleavage of prekallikrein by prolylcarboxypeptidase, and that the resulting kallikrein catalyzes the activation of factor XII (Schmaier 2004). The second group of events, occurs in vivo on the surfaces of activated platelets (although most biochemical characterization of the reactions was originally done with purified proteins in solution). Factor XI binds to the platelet glycoprotein (GP) Ib:IX:V complex, where it can be activated by cleavage either by thrombin (generated by reactions of the common pathway) or by activated factor XII (generated in the first part of the intrinsic pathway). Activated factor XI in turn catalyzes the activation of factor IX. Simultaneously, factor VIII, complexed with vWF, is cleaved by thrombin, activating it and causing its release from vWF. Activated factors VIII and IX form a complex on the platelet surface that very efficiently converts factor X to activated factor X. (Activated factors X and V then form a complex that efficiently activates thrombin.) While these two groups of events can be viewed as forming a single functional pathway (e.g., Davie et al. 1991), human clinical genetic data cast doubt on this view. Individuals deficient in kininogen, prekallikrein, or factor XII proteins exhibit normal blood clot formation in vivo. In contrast, deficiencies of factor XI can be associated with failure of blood clotting under some conditions, and deficiencies of vWF, factor VIII, or factor IX cause severe abnormalities - von Willebrand disease, hemophilia A, and hemophilia B, respectively. These data suggest that while the second group of events is essential for normal clot formation in vivo, the first group has a different function (e.g., Schmaier 2004). Finally, reactions neutralize proteins activated in the first part of the intrinsic pathway. Kallikrein forms stable complexes with either C1 inhibitor (C1Inh) or with alpha2-macroglobulin, and factor XIIa forms stable complexes with C1Inh. The relevance of these neutralization events to the regulation of blood clotting is unclear, however. The physiological abnormalities observed in individuals who lack C1Inh appear to be due entirely to abnormalities of complement activation; blood clotting appears to proceed normally. This observation is consistent with the hypothesis, above, that factor XIIa plays a limited role in normal blood clotting under physiological conditions."
BMGC_PW0511,BMG_PW2813,,,"The common pathway consists of the cascade of activation events leading from the formation of activated factor X to the formation of active thrombin, the cleavage of fibrinogen by thrombin, and the formation of cleaved fibrin into a stable multimeric, cross-linked complex. Thrombin also efficiently catalyzes the activation of several factors required earlier in the clotting cascade, thus acting in effect as a positive regulator of clotting. At the same time, thrombin activates protein C, which in turn catalyzes the inactivation of several of these upstream factors, thereby limiting the clotting process. Thrombin can be trapped in stable, inactive complexes with: antithrombin-III (SERPINC1), a circulating blood protein; heparin cofactor II (SERPIND1) which inhibits thrombin in a dermatan sulfate–dependent manner in the arterial vasculature; protein C inhibitor (SERPINA5) that inhibits thrombin in complex with thrombomodulin; and Protease nexin-1 (SERPINE2) that inhibits thrombin at the vessel wall and platelet surface. The quantitative interplay among these positive and negative modulators is critical to the normal regulation of clotting, facilitating the rapid formation of a protective clot at the site of injury, while limiting and physically confining the process. These events are outlined in the drawing: black arrows connect the substrates (inputs) and products (outputs) of individual reactions, and blue lines connect output activated enzymes to the other reactions that they catalyze."
BMGC_PW0512,BMG_PW2814,,,"Human monoamine oxidases (MAOs) are flavin-containing enzymes that are present on the outer mitochondrial membrane and act on primary, secondary and tertiary amines. In contrast to the P450s which have a large number of isozymes, MAOs number only two isozymes, MAO-A and MAO-B. These gene products share over 70% sequence identity, are approximately 59KDa in size and have overlapping substrates (for example dopamine, tryamine and tryptamine) but each form also has distinct substrate specificities. MAO-A (primary type in fibroblasts) preferentially oxidises serotonin (5-Hydroxytryptamine) whereas MAO-B (primary type in platelets) prefers phenylethylamine. MAOs are of particular clinical interest because of the use of MAO inhibitors (MAOI) as antidepressants or in the treatment of neurodegenerative diseases Benedetti 2001, Beedham 1997)."
BMGC_PW0513,BMG_PW2816,,,"The target of the mitotic checkpoint is the Anaphase Promoting Complex/Cyclosome (APC/C) an E3 ubiquitin ligase that targets proteins whose destruction is essential for mitotic exit. Currently, there are two proposed mechanism by which inhibition of the APC/C is achieved. These mechanisms differ depending on the mechanism of signal transduction. The APC/C may be inhibited directly by association with the Mitotic Checkpoint Complex (MCC) or through the sequestration of its activator, Cdc20."
BMGC_PW0514,BMG_PW2818,,,"In the direct inhibition model, the cytosolic Mitotic Checkpoint Complex, consisting of hBUBR1, hBUB3, Cdc20 and Mad2, directly inhibits APC/C by binding to it."
BMGC_PW0515,BMG_PW2820,,,"Pyruvate metabolism and the citric acid (TCA) cycle together link the processes of energy metabolism in a human cell with one another and with key biosynthetic reactions. Pyruvate, derived from the reversible oxidation of lactate or transamination of alanine, can be converted to acetyl CoA. Other sources of acetyl CoA include breakdown of free fatty acids and ketone bodies in the fasting state. Acetyl CoA can enter the citric acid cycle, a major source of reducing equivalents. These reducing equivalents are re-oxidized back to NAD+ in the electron transport chain (ETC), coupling this process with the export of protons across the inner mitochondrial membrane. The chemiosmotic gradient created is used to drive ATP synthesis. In addition to its role in energy generation, the citric acid cycle is a source of carbon skeletons for amino acid metabolism and other biosynthetic processes. One such process included here is the interconversion of 2-hydroxyglutarate, probably derived from porphyrin and amino acid metabolism, and 2-oxoglutarate (alpha-ketoglutarate), a citric acid cycle intermediate."
BMGC_PW0516,BMG_PW2821,,,"SCF induced proliferation is negatively regulated by various proteins including SHP1, PKC, CBL, SOCS1, SOCS6 and LNK."
BMGC_PW0517,BMG_PW2822,,,"Mature NODAL can form heterodimers with LEFTY1, LEFTY2, or CERBERUS. The heterodimers do not activate the NODAL receptor. LEFTY1 and LEFTY2 also bind CRIPTO and CRYPTIC coreceptors and prevent them from interacting with other components of the NODAL receptor. By these mechanisms LEFTY1, LEFTY2, and CERBERUS negatively regulate NODAL signaling (reviewed in Shen 2007, Schier 2009)."
BMGC_PW0518,BMG_PW2823,,,"Collagen fibril diameter and spatial organisation are dependent on the species, tissue type and stage of development (Parry 1988). The lengths of collagen fibrils in mature tissues are largely unknown but in tendon can be measured in millimetres (Craig et al. 1989). Collagen fibrils isolated from adult bovine corneal stroma had ~350 collagen molecules in transverse section, tapering down to three molecules at the growing tip (Holmes & Kadler 2005). The classical view of collagenases is that they actively unwind the triple helical chain, a process termed molecular tectonics (Overall 2002, Bode & Maskos 2003), before preferentially cleaving the alpha2 chain followed by the remaining chains (Chung et al. 2004). More recently it has been suggested that collagen fibrils exist in an equilibrium between protected and vulnerable states (Stultz 2002, Nerenberg & Stultz 2008). The prototypical triple-helical structure of collagen does not fit into the active site of collagenase MMPs. In addition the scissile bonds are not solvent-exposed and are therefore inaccessible to the collagenase active site (Chung et al. 2004, Stultz 2002). It was realized that collagen must locally unfold into non-triple helical regions to allow collagenolysis. Observations using circular dichroism and differential scanning calorimetry confirm that there is considerable heterogeneity along collagen fibres (Makareeva et al. 2008) allowing access for MMPs at physiological temperatures (Salsas-Escat et al. 2010). Collagen fibrils with cut chains are unstable and accessible to proteinases that cannot cleave intact collagen strands (Woessner & Nagase 2000, Somerville et al. 2003). Continued degradation leads to the formation of gelatin (Lovejoy et al. 1999). Degradation of collagen types other than I-III is less well characterized but believed to occur in a similar manner. Metalloproteinases (MMPs) play a major part in the degradation of several extracellular macromolecules including collagens. MMP1 (Welgus et al. 1981), MMP8 (Hasty et al. 1987), and MMP13 (Knauper et al. 1996), sometimes referred to as collagenases I, II and III respectively, are able to initiate the intrahelical cleavage of the major fibril forming collagens I, II and III at neutral pH, and thus thought to define the rate-limiting step in normal tissue remodeling events. All can cleave additional substrates including other collagen subtypes. Collagenases cut collagen alpha chains at a single conserved Gly-Ile/Leu site approximately 3/4 of the molecule's length from the N-terminus (Fields 1991, Chung et al. 2004). The cleavage site is characterised by the motif G(I/L)(A/L); the G-I/L bond is cleaved. In collagen type I this corresponds to G953-I954 in the Uniprot canonical alpha chain sequences (often given as G775-I776 in literature). It is not clear why only this bond is cleaved, as the motif occurs at several other places in the chain. MMP14, a membrane-associated MMP also known as Membrane-type matrix metalloproteinase 1 (MT-MMP1), is able to cleave collagen types I, II and III (Ohuchi et al. 1997)."
BMGC_PW0519,BMG_PW2824,,,"In adipocytes and myocytes insulin signaling causes intracellular vesicles carrying the GLUT4 (SLC2A4) glucose transporter to translocate to the plasma membrane, allowing the cells to take up glucose from the bloodstream (reviewed in Zaid et al. 2008, Leney and Tavare 2009, Bogan and Kandror 2010, Foley et al. 2011, Hoffman and Elmendorf 2011, Kandror and Pilch 2011, Jaldin-Fincati et al. 2017). In myocytes muscle contraction alone can also cause translocation of GLUT4. Though the entire pathway leading to GLUT4 translocation has not been elucidated, several steps are known. Insulin activates the kinases AKT1 and AKT2. Muscle contraction activates the kinase AMPK-alpha2 and possibly also AKT. AKT2 and, to a lesser extent, AKT1 phosphorylate the RAB GTPase activators TBC1D1 and TBC1D4, causing them to bind 14-3-3 proteins and lose GTPase activation activity. As a result RAB proteins (probably RAB8A, RAB10, RAB14 and possibly RAB13) accumulate GTP. The connection between RAB:GTP and vesicle translocation is unknown but may involve recruitment and activation of myosins. Myosins 1C, 2A, 2B, 5A, 5B have all been shown to play a role in translocating GLUT4 vesicles near the periphery of the cell. Following docking at the plasma membrane the vesicles fuse with the plasma membrane in a process that depends on interaction between VAMP2 on the vesicle and SNAP23 and SYNTAXIN-4 at the plasma membrane."
BMGC_PW0520,BMG_PW2825,,,"Humans have 38 beta-defensin genes plus 9-10 pseudogenes (details available on the HGNC website at http://www.genenames.org/genefamilies/DEFB). Many beta-defensins are encoded by recently duplicated genes giving rise to identical transcripts. Nomenclature is confusing and currently in transition. Uniprot recommended names are used throughout this pathway. Many beta-defensins show expression that correlates with infection (Sahl et al. 2005, Pazgier et al. 2006). All so far characterized beta-defensins, i.e. beta-defensin 1 (hBD1), 4A (hBD2), 103 (hBD3), 104 (hBD4), 106 (hBD6), 118 (hBD18) and 128 (hBD28) have antimicrobial properties (Pazgier et al. 2006). For beta-defensins 4A, 103 and 118 (hBD2, 3, and 18) this has been shown to correlate with membrane permeabilization effects (Antcheva et al. 2004, Sahl et al. 2005, Yenugu et al. 2004). Electrostatic interaction and disruption of microbial membranes is widely believed to the primary mechanism of action for beta-defensins. Two models explain how membrane disruption takes place, the 'pore model' which postulates that beta-defensins form transmembrane pores in a similar manner to alpha-defensins, and the 'carpet model', which suggests that beta-defensins act as detergents. Beta-defensins contain 6 conserved cysteine residues that in beta-defensins 1, 4A and 103 (hBD1-3) are experimentally confirmed to be cross-linked 1-5, 2-4, 3-6. The canonical sequence for beta-defensins is x2-10Cx5-6(G/A)xCX3-4Cx9-13Cx4-7CCxn. Structurally they are similar to alpha-defensins but with much shorter pre-regions. Though dimerization of some beta-defensins has been reported this is not the case for all and it is unclear whether it is required for function. The majority of functional studies have focused on beta-defensin 103 (hBD3), which has the most significant antimicrobial activity at physiological salt concentrations (Harder et al. 2001). Beta-defensin 103 is highly cationic with a net charge of +11 e0. It exhibits broad-spectrum antimicrobial activity against gram-positive bacteria and some gram-negative bacteria (Harder et al. 2001), though some species are highly resistant (Sahly et al. 2003). Sensitivity correlates with lipid composition of the membrane, with more negatively-charged lipids correlating with larger beta-defensin 103-induced changes in membrane capacitance (Bohling et al. 2006). Though membrane disruption is widely believed to be the primary mechanism of action of beta-defensins they have other antimicrobial properties, such as inhibition of cell wall biosynthesis (Sass et al. 2010), and chemoattractant effects (Yang et al. 1999, Niyonsaba et al. 2002, 2004). The chemotactic activity of beta-defensins 1, 4A and 103 (hBD1-3) for memory T cells and immature DCs is mediated through binding to the chemokine receptor CCR6 and probably another unidentified Gi-coupled receptor (Yang et al. 1999, 2000). Like defensins, the human cathelicidin LL37 peptide is rich in positively-charged residues (Lehrer & Ganz 2002). Expression of certain beta-defensins can be induced in response to various signals, such as bacteria, pathogen-associated molecular patterns (PAMPs), or proinflammatory cytokines (Ganz 2003, Yang et al. 2004). Like the alpha-defensins, copy number variation has been reported for DEFB4, DEFB103 and DEFB104 with individuals having 2-12 copies per diploid genome. In contrast DEFB1 does not show such variation but exhibits a number of SNPs (Hollox et al. 2003, Linzmier & Ganz 2005)."
BMGC_PW0521,BMG_PW2826,,,"The defensins are a family of antimicrobial cationic peptide molecules which in mammals have a characteristic beta-sheet-rich fold and framework of six disulphide-linked cysteines (Selsted & Ouellette 2005, Ganz 2003). Human defensin peptides have two subfamilies, alpha- and beta-defensins, differing in the length of peptide chain between the six cysteines and the order of disulphide bond pairing between them. A third subfamily, the theta defensins, is derived from alpha-defensins prematurely truncated by a stop codon between the third and fourth cysteine residues. The translated products are shortened to nonapeptides, covalently dimerized by disulfide linkages, and cyclized via new peptide bonds between the first and ninth residues. Humans have one pseudogene but no translated representatives of the theta class. In solution most alpha and beta defensins are monomers but can form dimers and higher order structures. The primary cellular sources of defensins are neutrophils, epithelial cells and intestinal Paneth cells.Those expressed in neutrophils and the gut are predominantly constitutive, while those in epithelial tissues such as skin are often inducible by proinflammatory stimuli such as LPS or TNF-alpha. Defensins are translated as precursor polypeptides that include a typical signal peptide or prepiece that is cleaved in the Golgi body, and a propiece, cleaved by differing mechanisms to produce the mature defensin. Mature defensin peptides can be further processed by removal of individual N-terminal residues (Yang et al. 2004). This may be a mechanism to broaden the activity profile of defensins (Ghosh et al. 2002). Defensins have direct antimicrobial effects and kill a wide range of Gram-positive and negative bacteria, fungi and some viruses. The primary antimicrobial action of defensins is permeabilization of microbial target membranes but several additional mechanisms have been suggested (Brogden 2005, Wilmes et al. 2011). Defensins and related antimicrobial peptides such as cathelicidin bridge the innate and acquired immune responses. In addition to their antimicrobial properties, cathelicidin and several defensins show receptor-mediated chemotactic activity for immune cells such as monocytes, T cells or immature DCs, induce cytokine production by monocytes and epithelial cells, modulate angiogenesis and stimulate wound healing (Yang et al. 1999, 2000, 2004, Rehaume & Hancock 2008, Yeung et al. 2011)."
BMGC_PW0522,BMG_PW2827,,,"Humans have 7 alpha defensin genes plus 5 pseudogenes (see HGNC at http://www.genenames.org/genefamilies/DEFA). Alpha-defensins have six cysteines linked 1-6, 2-4, 3-5. The canonical sequence of alpha-defensins in humans is x1-2CXCRx2-3Cx3Ex3GxCx3Gx5CCx1-4, where x represents any amino acid residue. Human alpha-defensins 1-4 are often called human neutrophil peptides (HNP1-4) as they were initially identified in neutrophil primary (azurophilic) granules. Alpha-defensins 5 and 6 (HD5, HD6) are products of Paneth cells. HNP-1 and -3 peptides are 30 residues long, differing only in the first amino acid. They are encoded by the genes DEFA1 and DEFA3 respectively. These exhibit copy number polymorphism, with some individuals having 4-14 copies per diploid genome, while 10-37% of individuals have no copies of DEFA3 (Aldred et al. 2005, Linzmier & Ganz 2005, Ballana et al. 2007). HNP-4, encoded by DEFA4, is 33 amino acids long of which 22 differ from the other HNPs (Wilde et al. 1989). It is a minor component of neutrophil granules compared to HNP1-3. In contrast to DEFA1 and DEFA3, the genes for HNP-4, HD-5 and HD-6 are only found as two copies per diploid genome (Linzmeier & Ganz 2005). HNP-2 is 29 amino acids in length and is the proteolytic product of cleavage of the N-terminal amino acid from either HNP-1 and/or HNP-3 (Selsted et al. 1985)."
BMGC_PW0523,BMG_PW2828,,,"Tetrahydrobiopterin (BH4) is an essential co-factor for the aromatic amino acid hydroxylases and glycerol ether monooxygenase and it regulates nitric oxide synthase (NOS) activity. Inherited BH4 deficiency leads to hyperphenylalaninemia, and dopamine and neurotransmitter deficiency in the brain. BH4 maintains enzymatic coupling to L-arginine oxidation to produce NO. Oxidation of BH4 to BH2 results in NOS uncoupling, resulting in superoxide (O2.-) formation rather than NO. Superoxide rapidly reacts with NO to produce peroxynitrite which can further uncouple NOS. These reactive oxygen species (superoxide and peroxynitrite) can contribute to increased oxidative stress in the endothelium leading to atherosclerosis and hypertension (Thony et al. 2000, Crabtree and Channon 2011,Schulz et al. 2008, Schmidt and Alp 2007). The synthesis, recycling and effects of BH4 are shown here. Three enzymes are required for the de novo biosynthesis of BH4 and two enzymes for the recycling of BH4."
BMGC_PW0524,BMG_PW2829,,,"Human reproduction mixes the genomes of two individuals, creating a new organism. The offspring individuals produced by sexual reproduction differ from their parents and from their siblings. Reproduction includes the reproductive system, sperm and egg production (haploid cells), fertilization, and the early stages embryo development."
BMGC_PW0525,BMG_PW2830,,,"Matrix metalloproteinases (MMPs), previously referred to as matrixins because of their role in degradation of the extracellular matrix (ECM), are zinc and calcium dependent proteases belonging to the metzincin family. They contain a characteristic zinc-binding motif HEXXHXXGXXH (Stocker & Bode 1995) and a conserved Methionine which forms a Met-turn. Humans have 24 MMP genes giving rise to 23 MMP proteins, as MMP23 is encoded by two identical genes. All MMPs contain an N-terminal secretory signal peptide and a prodomain with a conserved PRCGXPD motif that in the inactive enzyme is localized with the catalytic site, the cysteine acting as a fourth unpaired ligand for the catalytic zinc atom. Activation involves delocalization of the domain containing this cysteine by a conformational change or proteolytic cleavage, a mechanism referred to as the cysteine-switch (Van Wart & Birkedal-Hansen 1990). Most MMPs are secreted but the membrane type MT-MMPs are membrane anchored and some MMPs may act on intracellular proteins. Various domains determine substrate specificity, cell localization and activation (Hadler-Olsen et al. 2011). MMPs are regulated by transcription, cellular location (most are not activated until secreted), activating proteinases that can be other MMPs, and by metalloproteinase inhibitors such as the tissue inhibitors of metalloproteinases (TIMPs). MMPs are best known for their role in the degradation and removal of ECM molecules. In addition, cleavage of the ECM and other cell surface molecules can release ECM-bound growth factors, and a number of non-ECM proteins are substrates of MMPs (Nagase et al. 2006). MMPs can be divided into subgroups based on domain structure and substrate specificity but it is clear that these are somewhat artificial, many MMPs belong to more than one functional group (Vise & Nagase 2003, Somerville et al. 2003)."
BMGC_PW0526,BMG_PW2831,,,"The extracellular matrix is a component of all mammalian tissues, a network consisting largely of the fibrous proteins collagen, elastin and associated-microfibrils, fibronectin and laminins embedded in a viscoelastic gel of anionic proteoglycan polymers. It performs many functions in addition to its structural role; as a major component of the cellular microenvironment it influences cell behaviours such as proliferation, adhesion and migration, and regulates cell differentiation and death (Hynes 2009). ECM composition is highly heterogeneous and dynamic, being constantly remodeled (Frantz et al. 2010) and modulated, largely by matrix metalloproteinases (MMPs) and growth factors that bind to the ECM influencing the synthesis, crosslinking and degradation of ECM components (Hynes 2009). ECM remodeling is involved in the regulation of cell differentiation processes such as the establishment and maintenance of stem cell niches, branching morphogenesis, angiogenesis, bone remodeling, and wound repair. Redundant mechanisms modulate the expression and function of ECM modifying enzymes. Abnormal ECM dynamics can lead to deregulated cell proliferation and invasion, failure of cell death, and loss of cell differentiation, resulting in congenital defects and pathological processes including tissue fibrosis and cancer. Collagen is the most abundant fibrous protein within the ECM constituting up to 30% of total protein in multicellular animals. Collagen provides tensile strength. It associates with elastic fibres, composed of elastin and fibrillin microfibrils, which give tissues the ability to recover after stretching. Other ECM proteins such as fibronectin, laminins, and matricellular proteins participate as connectors or linking proteins (Daley et al. 2008). Chondroitin sulfate, dermatan sulfate and keratan sulfate proteoglycans are structural components associated with collagen fibrils (Scott & Haigh 1985; Scott & Orford 1981), serving to tether the fibril to the surrounding matrix. Decorin belongs to the small leucine-rich repeat proteoglycan family (SLRPs) which also includes biglycan, fibromodulin, lumican and asporin. All appear to be involved in collagen fibril formation and matrix assembly (Ameye & Young 2002). ECM proteins such as osteonectin (SPARC), osteopontin and thrombospondins -1 and -2, collectively referred to as matricellular proteins (reviewed in Mosher & Adams 2012) appear to modulate cell-matrix interactions. In general they induce de-adhesion, characterized by disruption of focal adhesions and a reorganization of actin stress fibers (Bornstein 2009). Thrombospondin (TS)-1 and -2 bind MMP2. The resulting complex is endocytosed by the low-density lipoprotein receptor-related protein (LRP), clearing MMP2 from the ECM (Yang et al. 2001). Osteopontin (SPP1, bone sialoprotein-1) interacts with collagen and fibronectin (Mukherjee et al. 1995). It also contains several cell adhesive domains that interact with integrins and CD44. Aggrecan is the predominant ECM proteoglycan in cartilage (Hardingham & Fosang 1992). Its relatives include versican, neurocan and brevican (Iozzo 1998). In articular cartilage the major non-fibrous macromolecules are aggrecan, hyaluronan and hyaluronan and proteoglycan link protein 1 (HAPLN1). The high negative charge density of these molecules leads to the binding of large amounts of water (Bruckner 2006). Hyaluronan is bound by several large proteoglycans proteoglycans belonging to the hyalectan family that form high-molecular weight aggregates (Roughley 2006), accounting for the turgid nature of cartilage. The most significant enzymes in ECM remodeling are the Matrix Metalloproteinase (MMP) and A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) families (Cawston & Young 2010). Other notable ECM degrading enzymes include plasmin and cathepsin G. Many ECM proteinases are initially present as precursors, activated by proteolytic processing. MMP precursors include an amino prodomain which masks the catalytic Zn-binding motif (Page-McCawet al. 2007). This can be removed by other proteinases, often other MMPs. ECM proteinases can be inactivated by degradation, or blocked by inhibitors. Some of these inhibitors, including alpha2-macroglobulin, alpha1-proteinase inhibitor, and alpha1-chymotrypsin can inhibit a large variety of proteinases (Woessner & Nagase 2000). The tissue inhibitors of metalloproteinases (TIMPs) are potent MMP inhibitors (Brew & Nagase 2010)."
BMGC_PW0527,BMG_PW2832,,,"Collagen is a family of at least 29 structural proteins derived from over 40 human genes (Myllyharju & Kivirikko 2004). It is the main component of connective tissue, and the most abundant protein in mammals making up about 25% to 35% of whole-body protein content. A defining feature of collagens is the formation of trimeric left-handed polyproline II-type helical collagenous regions. The packing within these regions is made possible by the presence of the smallest amino acid, glycine, at every third residue, resulting in a repeating motif Gly-X-Y where X is often proline (Pro) and Y often 4-hydroxyproline (4Hyp). Gly-Pro-Hyp is the most common triplet in collagen (Ramshaw et al. 1998). Collagen peptide chains also have non-collagenous domains, with collagen subclasses having common chain structures. Collagen fibrils are mostly found in fibrous tissues such as tendon, ligament and skin. Other forms of collagen are abundant in cornea, cartilage, bone, blood vessels, the gut, and intervertebral disc. In muscle tissue, collagen is a major component of the endomysium, constituting up to 6% of muscle mass. Gelatin, used in food and industry, is collagen that has been irreversibly hydrolyzed. On the basis of their fibre architecture in tissues, the genetically distinct collagens have been divided into subgroups. Group 1 collagens have uninterrupted triple-helical domains of about 300 nm, forming large extracellular fibrils. They are referred to as the fibril-forming collagens, consisting of collagens types I, II, III, V, XI, XXIV and XXVII. Group 2 collagens are types IV and VII, which have extended triple helices (>350 nm) with imperfections in the Gly-X-Y repeat sequences. Group 3 are the short-chain collagens. These have two subgroups. Group 3A have continuous triple-helical domains (type VI, VIII and X). Group 3B have interrupted triple-helical domains, referred to as the fibril-associated collagens with interrupted triple helices (FACIT collagens, Shaw & Olsen 1991). FACITs include collagen IX, XII, XIV, XVI, XIX, XX, XXI, XXII and XXVI plus the transmembrane collagens (XIII, XVII, XXIII and XXV) and the multiple triple helix domains and interruptions (Multiplexin) collagens XV and XVIII (Myllyharju & Kivirikko 2004). The non-collagenous domains of collagens have regulatory functions; several are biologically active when cleaved from the main peptide chain. Fibrillar collagen peptides all have a large triple helical domain (COL1) bordered by N and C terminal extensions, called the N- and C-propeptides, which are cleaved prior to formation of the collagen fibril. The intact form is referred to as a collagen propeptide, not procollagen, which is used to refer to the trimeric triple-helical precursor of collagen before the propeptides are removed. The C-propeptide, also called the NC1 domain, directs chain association during assembly of the procollagen molecule from its three constituent alpha chains (Hulmes 2002). Fibril forming collagens are the most familiar and best studied subgroup. Collagen fibres are aggregates or bundles of collagen fibrils, which are themselves polymers of tropocollagen complexes, each consisting of three polypeptide chains known as alpha chains. Tropocollagens are considered the subunit of larger collagen structures. They are approximately 300 nm long and 1.5 nm in diameter, with a left-handed triple-helical structure, which becomes twisted into a right-handed coiled-coil 'super helix' in the collagen fibril. Tropocollagens in the extracellular space polymerize spontaneously with regularly staggered ends (Hulmes 2002). In fibrillar collagens the molecules are staggered by about 67 nm, a unit known as D that changes depending upon the hydration state. Each D-period contains slightly more than four collagen molecules so that every D-period repeat of the microfibril has a region containing five molecules in cross-section, called the 'overlap', and a region containing only four molecules, called the 'gap'. The triple-helices are arranged in a hexagonal or quasi-hexagonal array in cross-section, in both the gap and overlap regions (Orgel et al. 2006). Collagen molecules cross-link covalently to each other via lysine and hydroxylysine side chains. These cross-links are unusual, occuring only in collagen and elastin, a related protein. The macromolecular structures of collagen are diverse. Several group 3 collagens associate with larger collagen fibers, serving as molecular bridges which stabilize the organization of the extracellular matrix. Type IV collagen is arranged in an interlacing network within the dermal-epidermal junction and vascular basement membranes. Type VI collagen forms distinct microfibrils called beaded filaments. Type VII collagen forms anchoring fibrils. Type VIII and X collagens form hexagonal networks. Type XVII collagen is a component of hemidesmosomes where it is complexed wtih alpha6Beta4 integrin, plectin, and laminin-332 (de Pereda et al. 2009). Type XXIX collagen has been recently reported to be a putative epidermal collagen with highest expression in suprabasal layers (Soderhall et al. 2007). Collagen fibrils/aggregates arranged in varying combinations and concentrations in different tissues provide specific tissue properties. In bone, collagen triple helices lie in a parallel, staggered array with 40 nm gaps between the ends of the tropocollagen subunits, which probably serve as nucleation sites for the deposition of crystals of the mineral component, hydroxyapatite (Ca10(PO4)6(OH)2) with some phosphate. Collagen structure affects cell-cell and cell-matrix communication, tissue construction in growth and repair, and is changed in development and disease (Sweeney et al. 2006, Twardowski et al. 2007). A single collagen fibril can be heterogeneous along its axis, with significantly different mechanical properties in the gap and overlap regions, correlating with the different molecular organizations in these regions (Minary-Jolandan & Yu 2009)."
BMGC_PW0528,BMG_PW2833,,,"Carbonic anhydrases reversibly catalyze the hydration of carbon dioxide and directly produce bicarbonate and protons, bypassing the formation of carbonic acid (reviewed in Lindskog 1997, Breton 2001, Esbaugh and Tufts 2006, Boron 2010, Gilmour 2010). Carbonic anhydrase deprotonates water to yield a zinc-hydroxyl group and a proton which is transferred to external buffer molecules via histidine or glutamate residues in carbonic anhydrase. The hydroxyl group reacts with carbon dioxide in the active site to yield bicarbonate. A water molecule displaces the bicarbonate and the reaction cycle begins again. There are currently 12 known active carbonic anhydrases in humans."
BMGC_PW0529,BMG_PW2834,,,"In capillaries of the lungs Erythrocytes take up oxygen and release carbon dioxide. In other tissues of the body the reverse reaction occurs: Erythrocytes take up carbon dioxide and release oxygen (reviewed in Nikinmaa 1997, Jensen 2004). In the lungs, carbon dioxide (CO2) bound as carbamate to the N-terminus of hemoglobin (HbA) and protons bound to histidine residues in HbA are released as HbA binds oxygen (O2). Bicarbonate (HCO3-) present in plasma is taken up by erythrocytes via the band3 anion exchanger (AE1, SLC4A1) and combined with protons by carbonic anhydrases I and II (CA1, CA2) to yield water and CO2 (reviewed by Esbaugh & Tufts 2006, De Rosa et al. 2007). The CO2 is passively transported out of the erythrocyte by AQP1 and RhAG. HCO3- in plasma is also directly dehydrated by extracellular carbonic anhydrase IV (CA4) present on endothelial cells lining the capillaries in the lung. In non-pulmonary tissues CO2 in plasma is hydrated to yield protons and HCO3- by CA4 located on the apical plasma membranes of endothelial cells. Plasma CO2 is also taken up by erythrocytes via AQP1 and RhAG. Within erythrocytes CA1 and, predominantly, CA2 hydrate CO2 to yield HCO3- and protons (reviewed in Geers & Gros 2000, Jensen 2004, Boron 2010). HCO3- is transferred out of the erythrocyte by the band 3 anion exchange protein (AE1, SLC4A1) which cotransports a chloride ion into the erythrocyte. Also within the erythrocyte, CO2 combines with the N-terminal alpha amino groups of HbA to form carbamates while protons bind histidine residues in HbA. The net result is the Bohr effect, a conformational change in HbA that reduces its affinity for O2 and hence assists the delivery of O2 to tissues."
BMGC_PW0530,BMG_PW2835,,,"In the acyl chain remodelling pathway (Lands cycle), phosphatidylcholine (PC) is hydrolysed by phopholipases and subsequently reacylated by acyltransferases. These cycles modify the fatty acid composition of glycerophospholipids to generate diverse molecules asymmetrically distributed in the cell membrane (Ghomashchi et al. 2010, Singer et al. 2002, Cao et al. 2008, Zhao et al. 2008)."
BMGC_PW0531,BMG_PW2836,,,"Acyl chain remodeling of cardiolipin (CL) occurs in the inner mitochondria membranes (IM) via hydrolysis by phopholipases and subsequent reacylation by acyltransferases. At the endoplasmic reticulum (ER) membrane the situation is more complicated with monolysocardiolipin (MLCL) involved in hydrolysis and subsequent reacylation back to CL (Zachman et al. 2010, Malhotra et al. 2009, Xu et al. 2003, Taylor & Hatch 2009, Cao et al. 2004, Zhao et al. 2009, Buckland et al. 1998)."
BMGC_PW0532,BMG_PW2837,,,"In the acyl chain remodelling pathway (Lands cycle), phosphatidylserine (PS) is hydrolysed by phopholipases and subsequently reacylated by acyltransferases. These cycles modify the fatty acid composition of glycerophospholipids to generate diverse molecules asymmetrically distributed in the cell membrane (Ghomashchi et al. 2010, Singer et al. 2002, Cao et al. 2008; Hishikawa et al. 2008)."
BMGC_PW0533,BMG_PW2838,,,"In the acyl chain remodelling pathway (Lands cycle), phosphatidylethanolamine (PE) is hydrolyzed by phopholipases and subsequently reacylated by acyltransferases. These cycles modify the fatty acid composition of glycerophospholipids to generate diverse molecules asymmetrically distributed in the cell membrane (Ghomashchi et al. 2010, Singer et al. 2002, Cao et al. 2008, Zhao et al. 2008, Hishikawa et al. 2008)."
BMGC_PW0534,BMG_PW2839,,,"Acyl chain remodeling of triacylglycerol (TAG) and diacylglycerol (DAG) progresses through their hydrolysis by patatin-like phospholipase domain-containing proteins 2/3 (PNPLA2/3). DAG is reacylated back to TAG by acylglycerol O-acyltransferase 1/2 (DGAT1/2), while DAG and its hydrolysis product 2-monoacylglycerol (2-MAG) are transacylated back to TAG by PNPLA2/3. In addition, the DAG hydrolysis product 2-MAG is subsequently hydrolyzed to fatty acid and glycerol by monoglyceride lipase (MGLL) (Jenkins et al. 2004)."
BMGC_PW0535,BMG_PW2840,,,"In the acyl chain remodelling pathway (Lands cycle), phosphatidylinositol (PI) is hydrolyzed by phospholipases and subsequently reacylated by acyltransferases. These cycles modify the fatty acid composition of glycerophospholipids to generate diverse molecules asymmetrically distributed in the cell membrane (Ghomashchi et al. 2010, Singer et al. 2002, Gijon et al. 2008, Lee et al. 2008)."
BMGC_PW0536,BMG_PW2841,,,"In the acyl chain remodelling pathway (Lands cycle), phosphatidylglycerol (PG) is hydrolyzed by phopholipases and subsequently reacylated by acyltransferases. These cycles modify the fatty acid composition of glycerophospholipids to generate diverse molecules asymmetrically distributed in the cell membrane. The events occur additionally in the inner mitochondria membranes (IM) as well as in the endoplasmic reticulum (ER) membrane (Ghomashchi et al. 2010, Singer et al. 2002, Cao et al. 2008, Yang et al. 2004, Nie et al. 2010)."
BMGC_PW0537,BMG_PW2843,,,"Lysophosphatidylcholine (LPC) is hydrolyzed by phospholipases to produce glycerophosphocholine (GPCho) which is in turn hydrolyzed by glycerophosphocholine phosphodiesterase to produce choline (Cho) and glycerol-3-phosphate (G3P) (Yamashita et al. 2009, Yamashita et al. 2005, Ghomashchi et al. 2010)."
BMGC_PW0538,BMG_PW2844,,,"Phosphatidylglycerol (PG) is synthesised at the inner mitochondrial (IM) membrane, phosphatidic acid (PA) and cytidine triphosphate (CTP) are converted into cytidine diphosphate-diacylglycerol (CDP-DAG), which in turn is converted with glycerol-3-phosphate (G3P) into phosphatidylglycerophosphate (PGP) and cytidine monophosphate (CMP). Finally, PGP is dephosphorylated to PG. In addition, PG can be synthesised at the endoplamic reticulum (ER) membrane when phospholipase D transphosphatidylates phosphatidylcholine (PC) with glycerol to displace choline (Cho) and form PG (Piazza & Marmer 2007, Stuhne-Sekalec et al. 1986, Lykidis et al. 1997, Cao & Hatch 1994)."
BMGC_PW0539,BMG_PW2846,,,"In the de novo synthesis of phosphatidic acid (PA), lysophosphatidic acid (LPA) is initially formed by the esterification of sn-1 by glycerol 3-phosphate acyltransferase (GPAT) from glycerol 3-phosphate (G3P). Next, LPA is converted to PA by a LPA acyltransferase (AGPAT, also known as LPAAT). In addition to this, PA is also formed when phosphatidylcholine (PC) is hydrolyzed by phospholipases D1 and D2 (PLD1 and 2). PA is involved in acyl chain remodeling via cleavage by phospholipases followed by reacylation by acyltransferases (Ghomashchi et al. 2010, Singer et al. 2002, Prasad et al. 2011, Shindou & Shimizu 2009, Cao et al. 2006)."
BMGC_PW0540,BMG_PW2849,,,"Glycerophospholipids are important structural and functional components of biological membranes and constituents of serum lipoproteins and the pulmonary surfactant. In addition, glycerophospholipids act as precursors of lipid mediators such as platelet-activating factor and eicosanoids. Cellular membranes contains a distinct composition of various glycerophospholipids such as phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylglycerol (PG), phosphatidylinositol (PI), cardiolipin (CL), lysophosphatidic acid (LPA) and lysobisphosphatidic acid (also known as bis(monoacylglycerol) hydrogen phosphate - BMP). Glycerophospholipids are first formed by the de novo (Kennedy) pathway using fatty acids activated as acyl-CoA donors. However, the acyl groups of glycerophospholipids are highly diverse and distributed in an asymmetric manner. Saturated and monounsaturated fatty acids are usually esterified at the sn-1 position, whereas polyunsaturated acyl groups are esterified at the sn-2 position. Subsequent acyl chain remodeling (Lands cycle) generates the diverse glycerophospholipid composition and asymmetry characteristic of cell membranes. In the de novo pathway of glycerophospholipid biosynthesis, lysophosphatidic acid (LPA) is initially formed from glycerol 3-phosphate (G3P). Next, LPA is converted to PA by a LPA acyltransferase (AGPAT, also known as LPAAT), then PA is metabolized into two types of glycerol derivatives. The first is diacylglycerol (DAG) which is converted to triacylglycerol (TAG), PC, and PE. Subsequently, PS is synthesized from PC or PE. The second is cytidine diphosphate-diacylglycerol (CDP-DAG), which is processed into PI, PG, CL, and BMP. Each glycerophospholipid is involved in acyl chain remodeling via cleavage by phospholipases followed by reacylation by an acyltransferase. Most of the glycerophospholipids are synthesized at the endoplasmic reticulum (ER), however, some, most notably cardiolipin, and BMP are synthesized in the mitochondrial and endosomal membranes respectively. Since the most of the glycerophospholipids are found in all membrane compartments, there must be extensive network of transport of glycerophospholipids from one membrane compartment to another via various mechanisms including diffusion through the cytosol, formation of transportation complexes, and diffusion via membrane contact sites (MCS) (Osman et al. 2011, Lebiedzinska et al. 2009, Lev 2010, Scherer & Schmitz 2011, Orso et al. 2011, Hermansson et al. 2011, Vance & Vance 2008)."
BMGC_PW0541,BMG_PW2850,,,"De novo (Kennedy pathway) synthesis of phosphatidylethanolamine (PE) involves phosphorylation of ethanolamine (ETA) to phosphoethanolamine (PETA) followed by condensing with cytidine triphosphate (CTP) to form CDP-ethanolamine (CDP-ETA). Diacylglycerol (DAG) and CDP-ETA together then form PE. Alternatively, PE is formed when phosphatidylserine (PS) is decarboxylated by phosphatidylserine decarboxylase proenzyme (PISD) (Henneberry et al. 2002, Vance 1991, Vance 1990)."
BMGC_PW0542,BMG_PW2853,,,"Phospholipids contain a polar head group and two long-chain fatty acyl moieties, one of which is generally unsaturated. The head group is a glycerol or serine phosphate attached to a polar group such as choline. These molecules are a major constituent of cellular membranes, where their diverse structures and asymmetric distributions play major roles in determining membrane properties (Dowhan 1997). The four major classes of phospholipids in human plasma membranes are phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and sphingomyelin. The first three are derivatives of glycerol while sphingomyelin is a derivative of serine. Here, pathways for the metabolism of glycerophospholipids, phosphphatidylinositol (PI), and sphingolipids are annotated."
BMGC_PW0543,BMG_PW2854,,,This pathway describes the generation of DAG and IP3 by the PLCgamma-mediated hydrolysis of PIP2 and the subsequent downstream signaling events.
BMGC_PW0544,BMG_PW2855,,,"In G0 and early G1 in quiescent cells, p130 (RBL2) bound to E2F4 or E2F5 and either DP1 or DP2, associates with the MuvB complex, forming an evolutionarily conserved DREAM complex, that represses transcription of cell cycle genes. During early G1 phase in actively cycling cells, p107 (RBL1) forms a complex with E2F4 and DP1 or DP2 and represses transcription of E2F target genes. Both p130 (RBL2) and p107 (RBL1) repress transcription of E2F targets through recruiting histone deacetylase HDAC1, possibly in complex with other chromatin modifying enzymes, to E2F-regulated promoters. Expression of p107 (RBL1) is cell cycle regulated, with its levels peaking in late G1 and S phase. Although p107 (RBL1) is phosphorylated by cyclin D assocaited kinases during late G1 phase, a small pool of p107 (RBL1) is thought to be present throughout G1 and S phase, and could be involved in fine tuning the transcription of S-phase genes. This is supported by studies showing that unlike RB1 and p130 (RBL2), which are able to induce G1 arrest when over-expressed, p107 (RBL1) over-expression can arrest the cell cycle in both G1 and S phase. For recent reviews on the function of p107, p130 and pocket proteins in general, please refer to Wirt and Sage, 2010, MacPherson 2008 and Cobrinik 2005."
BMGC_PW0545,BMG_PW2856,,,"Methylation is a common but minor pathway of Phase II conjugation compared to glucuronidation or sulfonation. The cofactor used in methylation conjugation is S-adenosylmethionine (SAM). SAM is the second most widely used enzyme substrate after ATP and is involved in a wide range of important biological processes. SAM is sythesized from methionine's reaction with ATP, catalyzed by methionine adenosyltransferase (MAT). There are two genes, MAT1A and MAT2A, which encode for two homologous MAT catalytic subunits, 1 and 2. During conjugation with nucleophilic substrates, the methyl group attached to the sulfonium ion of SAM is transferred to the substrate forming the conjugate. SAM, having lost the methyl moiety, is converted to S-adenosylhomocysteine (SAH). SAH can be hydrolyzed to form adenosine and homocysteine. Homocysteine can either be converted to glutathione or methylated to form methionine, thus forming the starting point for SAM synthesis and completing the cycle. Fuctional groups attacked are phenols, catechols, aliphatic and aromatic amines and sulfhydryl-containing groups. The enzymes that catalyze the transfer of the methyl group to these functional groups are the methyltransferases (MT). MTs are small, cytosolic, monomeric enzymes that utilize SAM as a methyl donor. There are many MTs but the best studied ones are named on the basis of their prototypical substrates: COMT (catechol O-methyltransferase), TPMT (thiopurine methyltransferase), TMT (thiol methyltransferase), HNMT (histamine N-methyltransferase) and NNMT (nicotinamide N-methyltransferase). An example of each enzyme mentioned is given. In each case, a typical substrate for the enzyme is shown."
BMGC_PW0546,BMG_PW2857,,,"N-acetyltransferases (NATs; EC 2.3.1.5) utilize acetyl Co-A in acetylation conjugation reactions. This is the preferred route of conjugating aromatic amines (R-NH2, converted to aromatic amides R-NH-COCH3) and hydrazines (R-NH-NH2, converted to R-NH-NH-COCH3). Aliphatic amines are not substrates for NAT. The basic reaction is Acetyl-CoA + an arylamine = CoA + an N- acetylarylamine NATs are cytosolic and in humans, 2 isoforms are expressed, NAT1 and NAT2. A third isoform, NATP, is a pseudogene and is not expressed. The NAT2 gene contains mutations that decrease NAT2 activity. This mutations was first seen as slow acetylation compared to the normal, fast acetylation of the antituberculosis drug isoniazid. Incidence of the slow acetylator phenotype is high in Middle Eastern populations (70%), average (50%) in Europeans, Americans and Australians and low in Asians (<25% in Chinese, Japanese and Koreans). N-acetylation and methylation pathways differ from other conjugation pathways in that they mask an amine with a nonionizable group so that the conjugates are less water soluble than the parent compound. However, certain N-acetlylations facilitate urinary excretion. N-acetylation occurs in two sequential steps via a ping-pong Bi-Bi mechanism. In the first step, the acetyl group from acetyl-CoA is transferred to a cysteine residue in NAT, with consequent release of coenzyme-A. In the second step, the acetyl group is released from the acetylated NAT to the substrate, subsequently regenerating the enzyme."
BMGC_PW0547,BMG_PW2858,,,"Two groups of sulfotransferease (SULT) enzymes catalyze the transfer of a sulfate group from 3-phosphoadenosine 5-phosphosulfate (PAPS) to a hydroxyl group on an acceptor molecule, yielding a sulfonated acceptor and 3-phosphoadenosine 5-phosphate (PAP). One is localized to the Golgi apparatus and mediates the sulfonation of proteoglycans. The second, annotated here, is cytosolic and mediates the sulfonation of a diverse array of small molecules, increasing their solubilities in water and modifying their physiological functions. There are probably thirteen or more human cytosolic SULT enzymes; eleven of these have been purified and characterized enzymatically, and are annotated here (Blanchard et al. 2004; Gamage et al. 2005). These enzymes appear to be active as dimers. Their substrate specificities are typically broad, and not related in an obvious way to their structures; indeed, apparently orthologous human and rodent SULT enzymes can have different substrate specificities (Glatt 2000), and none has been exhaustively characterized. The substrates listed in the table and annotated here are a sample of the known ones, chosen to indicate the range of activity of these enzymes and to capture some of their known physiologically important targets. Absence of a small molecule - enzyme pair from the table, however, may only mean that it has not yet been studied."
BMGC_PW0548,BMG_PW2859,,,"Xenobiotics that contain either a carboxylic group or an aromatic hydroxylamine group are possible substrates for amino acid conjugation. Xenobiotics with a carboxylic group conjugate with an amino group of amino acids such as glycine, taurine and glutamine. The hydroxylamine group conjugates with the carboxylic group of amino acids such as proline and serine. The amino acid is first activated by an aminoacyl-tRNA-synthetase which then reacts with the hydroxylamine group to form a reactive N-ester. N-esters can degrade to form electrophilic nitrenium (R-N+-R') and carbonium (R-C+H2) ions. The pyrolysis product of tryptophan, an N-hydroxy intermediate, can potentially form these reactive electrophilic ions."
BMGC_PW0549,BMG_PW2860,,,"Elastic fibres (EF) are a major structural constituent of dynamic connective tissues such as large arteries and lung parenchyma, where they provide essential properties of elastic recoil and resilience. EF are composed of a central cross-linked core of elastin, surrounded by a mesh of microfibrils, which are composed largely of fibrillin. In addition to elastin and fibrillin-1, over 30 ancillary proteins are involved in mediating important roles in elastic fibre assembly as well as interactions with the surrounding environment. These include fibulins, elastin microfibril interface located proteins (EMILINs), microfibril-associated glycoproteins (MAGPs) and Latent TGF-beta binding proteins (LTBPs). Fibulin-5 for example, is expressed by vascular smooth muscle cells and plays an essential role in the formation of elastic fibres through mediating interactions between elastin and fibrillin (Yanigasawa et al. 2002, Freeman et al. 2005). In addition, it plays a role in cell adhesion through integrin receptors and has been shown to influence smooth muscle cell proliferation (Yanigasawa et al. 2002, Nakamura et al. 2002). EMILINs are a family of homologous glycoproteins originally identified in extracts of aortas. Found at the elastin-fibrillin interface, early studies showed that antibodies to EMILIN can affect the process of elastic fibre formation (Bressan et al. 1993). EMILIN1 has been shown to bind elastin and fibulin-5 and appears to coordinate their common interaction (Zanetti et al. 2004). MAGPs are found to co-localize with microfibrils. MAGP-1, for example, binds strongly to an N-terminal sequence of fibrillin-1. Other proteins found associated with microfibrils include vitronectin (Dahlback et al. 1990). Fibrillin is most familiar as a component of elastic fibres but microfibrils with no elastin are found in the ciliary zonules of the eye and invertebrate circulatory systems. The addition of elastin to microfibrils is a vertebrate adaptation to high pulsatile pressures in their closed circulatory systems (Faury et al. 2003). Elastin appears to have emerged after the divergence of jawless vertebrates from other vertebrates (Sage 1982). Fibrillin-1 is the major structural component of microfibrils. Fibrillin-2 is expressed earlier in development than fibrillin-1 and may be important for elastic fiber formation (Zhang et al. 1994). Fibrillin-3 arose as a duplication of fibrillin-2 that did not occur in the rodent lineage. It was first isolated from human brain (Corson et al. 2004). Fibrillin assembly is not as well defined as elastin assembly. The primary structure of fibrillin is dominated by calcium binding epidermal growth factor like repeats (Kielty et al. 2002). Fibrillin may form dimers or trimers before secretion. However, multimerisation predominantly occurs outside the cell. Formation of fibrils appears to require cell surface structures suggesting an involvement of cell surface receptors. Fibrillin is assembled pericellularly (i.e. on or close to the cell surface) into microfibrillar arrays that undergo time dependent maturation into microfibrils with beaded-string appearance. Transglutaminase forms gamma glutamyl epsilon lysine isopeptide bonds within or between peptide chains. Additionally, intermolecular disulfide bond formation between fibrillins is an important contributor to fibril maturation (Reinhardt et al. 2000). Models of fibrillin-1 microfibril structure suggest that the N-terminal half of fibrillin-1 is asymmetrically exposed in outer filaments, while the C-terminal half is buried in the interior (Kuo et al. 2007). Fibrillinopathies include Marfan syndrome, familial ectopia lentis, familial thoracic aneurysm, all due to mutations in the fibrillin-1 gene FBN1, and congenital contractural arachnodactyly which is caused by mutation of FBN2 (Maslen & Glanville 1993, Davis & Summers 2012). In vivo assembly of fibrillin requires the presence of extracellular fibronectin fibres (Sabatier et al. 2009). Fibrillins have Arg-Gly-Asp (RGD) sequences that interact with integrins (Pfaff et al. 1996, Sakamoto et al. 1996, Bax et al., 2003, Jovanovic et al. 2008) and heparin-binding domains that interact with a cell-surface heparan sulfate proteoglycan (Tiedemann et al. 2001) possibly a syndecan (Ritty et al. 2003). Fibrillins also have a major role in binding and sequestering growth factors such as TGF beta into the ECM (Neptune et al. 2003). Proteoglycans such as versican (Isogai et al. 2002), biglycan, and decorin (Reinboth et al. 2002) can interact with the microfibrils. They confer specific properties including hydration, impact absorption, molecular sieving, regulation of cellular activities, mediation of growth factor association, and release and transport within the extracellular matrix (Buczek-Thomas et al. 2002). In addition, glycosaminoglycans have been shown to interact with tropoelastin through its lysine side chains (Wu et al. 1999), regulating tropoelastin assembly (Tu & Weiss 2008). Elastin is synthesized as a 70kDa monomer called tropoelastin, a highly hydrophobic protein composed largely of two types of domains that alternate along the polypeptide chain. Hydrophobic domains are rich in glycine, proline, alanine, leucine and valine. These amino acids occur in characteristic short (3-9 amino acids) tandem repeats, with a flexible and highly dynamic structure (Floquet et al. 2004). Unlike collagen, glycine in elastin is not rigorously positioned every 3 residues. However, glycine is distributed frequently throughout all hydrophobic domains of elastin, and displays a strong preference for inter-glycine spacing of 0-3 residues (Rauscher et al. 2006). Elastic fibre formation involves the deposition of tropoelastin onto a template of fibrillin rich microfibrils. Recent results suggest that the first step of elastic fiber formation is the organization of small globules of elastin on the cell surface followed by globule aggregation into microfibres (Kozel et al. 2006). An important contribution to the initial stages assembly is thought to be made by the intrinsic ability of the protein to direct its own polymeric organization in a process termed 'coacervation' (Bressan et al. 1986). This self-assembly process appears to be determined by interactions between hydrophobic domains (Bressan et al. 1986, Vrhovski et al. 1997, Bellingham et al. 2003, Cirulis & Keeley 2010) which result in alignment of the cross-linking domains, allowing the stabilization of elastin through the formation of cross-links generated through the oxidative deamination of lysine residues, catalyzed by members of the lysyl oxidase (LOX) family (Reiser et al. 1992, Mithieux & Weiss 2005). The first step in the cross-linking reaction is the oxidative formation of the delta aldehyde, known as alpha aminoadipic semialdehyde or allysine (Partridge 1963). Subsequent reactions that are probably spontaneous lead to the formation of cross-links through dehydrolysinonorleucine and allysine aldol, a trifunctional cross-link dehydromerodesmosine and two tetrafunctional cross-links desmosine and isodesmosine (Lucero & Kagan 2006), which are unique to elastin. These cross-links confer mechanical integrity and high durability. In addition to their role in self-assembly, hydrophobic domains provide elastin with its elastomeric properties, with initial studies suggesting that the elastomeric propereties of elastin are driven through changes in entropic interactions with surrounding water molecules (Hoeve & Flory 1974). A very specific set of proteases, broadly grouped under the name elastases, is responsible for elastin remodelling (Antonicelli et al. 2007). The matrix metalloproteinases (MMPs) are particularly important in elastin breakdown, with MMP2, 3, 9 and 12 explicitly shown to degrade elastin (Ra & Parks 2007). Nonetheless, elastin typically displays a low turnover rate under normal conditions over a lifetime (Davis 1993)."
BMGC_PW0550,BMG_PW2861,,,"Fibronectin (FN1) is found in the extracellular matrix (ECM) of all cells as linear and branched networks that surround and connect neighbouring cells (Singh et al. 2010). Prior to matrix formation FN1 exists as a protein dimer. Often the two peptide chains represent differentially-spliced variants. The chains are linked by a pair of C-terminal disulfide bonds which are essential for subsequent multimerization (Schwarzbaur 1991). FN1 monomers have a molecular weight of 230-270 kDa depending on alternative splicing and contain three types of repeating unit, I, II, and III. I and II are stabilized by intra-chain disulfide bonds. The absence of disulfide bonds in type III modules allows them to partially unfold under applied force (Erickson 2002). Three regions of variable splicing occur along the length of the FN1 monomer (Mao & Schwarzbauer 2005). One or both of the 'extra' type III modules EIIIA and EIIIB may be present in cellular FN1, but never in plasma FN1. A variable (V) region exists between the 14th and 15th type III module. This contains the binding site for alpha4 beta1 and alpha4beta7 integrins. It is present in most cellular FN1, occasionally in plasma FN1. The modules are arranged into several functional and protein-binding domains. There are four FN1-binding domains (Mao & Schwarzbauer 2005). One of these domains (I1-5), referred to as the 'assembly domain', is required for the initiation of FN1 matrix assembly. Modules III9-10 correspond to the 'cell-binding domain' of FN1. The Arg-Gly-Asp (RGD) integrin binding sequence located in III10 is the primary site of FN1 to cell attachment, mediated predominantly by alpha5 beta1 and alphaV beta3 integrins. The 'synergy site' in III9 modulates FN1's association with alpha5 beta1 integrins. FN1 also contains interaction domains for fibrin (I1-5, I10-12), collagen (I6-9, II1-2), fibulin-1 (III13-14), heparin, syndecan (III12-14) and fibrillin-1 (I6-9) (Mao & Schwartzbauer 2005, Sabatier et al. 2009). FN1 dimer binding to alpha5beta1 integrin stimulates self-association. Binding is thought to lead to a conformational change in FN1 that triggers the addition of further FN1 dimers (Singh et al. 2010). I1-5 functions as a unit that is the primary FN1 matrix assembly domain (Sottile et al. 1991) but other units are likely to be involved (Singh et al. 2010), the process is not fully understood. Several ECM proteins appear to require the FN1 matrix for their own assembly. Fibrillin-1 containing microfibrils are formed when fibrillin-1 multimers bind to the FN1 matrix (Sabatier et al. 2009). FN1 polymerization promotes the deposition of type I and type III collagen (Sottile and Hocking 2002, Velling et al. 2002). Inhibition of FN1 polymerization increases its turnover and a concomitant loss of collagen types I and III from the ECM (Sottile and Hocking 2002, Sottile et al. 2007). FN1 is regulated by matrix metalloproteinases, particularly MMP14 (Shi & Sottile 2011)."
BMGC_PW0551,BMG_PW2862,,,"At mitotic entry, Plk1 phosphorylates and activates Cdc25C phosphatase, whereas it phosphorylates and down-regulates Wee1A (Watanabe et al. 2004). Plk1 also phosphorylates and inhibits Myt1 activity (Sagata 2005). Cyclin B1-bound Cdc2, which is the target of Cdc25C, Wee1A, and Myt1, functions in a feedback loop and phosphorylates the latter components (Cdc25C, Wee1A, Myt1). The Cdc2- dependent phosphorylation provides docking sites for the polo-box domain of Plk1, thus promoting the Plk1-dependent regulation of these components and, as a result, activation of Cdc2-Cyclin B1. PLK1 phosphorylates and activates the transcription factor FOXM1 which stimulates the expression of a number of genes needed for G2/M transition, including PLK1, thereby creating a positive feedback loop (Laoukili et al. 2005, Fu et al. 2008, Sadasivam et al. 2012, Chen et al. 2013)."
BMGC_PW0552,BMG_PW2863,,,"While circularization of mRNA during translation initiation is thought to contribute to an increase in the efficiency of translation, it also appears to provide a mechanism for translational silencing. This might be achieved by bringing inhibitory 3' UTR-binding proteins into a position in which they interfere either with the function of the translation initiation complex or with the assembly of the ribosome (Mazumder et al 2001). Translational silencing of Ceruloplasmin (Cp) occurs 16 hrs after its induction by INF-gamma (Mazumder et al., 1997). Although the mechanism by which silencing occurs has not yet been determined, this process is mediated by the L13a subunit of the 60s ribosome and thought to require circularization of the Cp mRNA (Sampath et al., 2003; Mazumder et al., 2001; Mazumder et al., 2003). Between 14 and 16 hrs after INF gamma induction, the L13a subunit of the 60s ribosome is phosphorylated and released from the 60s subunit. Phosphorylated L13a then associates with the GAIT element in the 3' UTR of the Cp mRNA inhibiting its translation."
BMGC_PW0553,BMG_PW2864,,,"The translation elongation cycle adds one amino acid at a time to a growing polypeptide according to the sequence of codons found in the mRNA. The next available codon on the mRNA is exposed in the aminoacyl-tRNA (aa-tRNA) binding site (A site) on the 30S subunit. A: Ternary complexes of aa -tRNA:eEF1A:GTP enter the ribosome and enable the anticodon of the tRNA to make a codon/anticodon interaction with the A-site codon of the mRNA. B: Upon cognate recognition, the eEF1A:GTP is brought into the GTPase activating center of the ribosome, GTP is hydrolyzed and eEF1A:GDP leaves the ribosome. C: The peptidyl transferase center of ribosome catalyses the formation of a peptide bond between the incoming amino acid and the peptide found in the peptidyl-tRNA binding site (P site). D: In the pre-translocation state of the ribosome, the eEF2:GTP enters the ribosome, physically translocating the peptidyl-tRNA out of the A site to P site and leaves the ribosome eEF2:GDP. This action of eEF2:GTP accounts for the precise movement of the mRNA by 3 nucleotides.Consequently, deacylated tRNA is shifted to the E site. A ribosome associated ATPase activity is proposed to stimulate the release of deacylated tRNA from the E site subsequent to translocation (Elskaya et al., 1991). In this post-translocation state, the ribosome is now ready to receive a new ternary complex. This process is illustrated below with: an amino acyl-tRNA with an amino acid, a peptidyl-tRNA with a growing peptide, a deacylated tRNA with an -OH, and a ribosome with A,P and E sites to accommodate these three forms of tRNA."
BMGC_PW0554,BMG_PW2865,,,"The mechanism of a peptide bond requires the movement of three protons. First the deprotonation of the ammonium ion generates a reactive amine, allowing a nucleophilic attack on the carbonyl group. This is followed by the loss of a proton from the reaction intermediate, only to be taken up by the oxygen on the leaving group (from the end of the amino acid chain bound to the tRNA in the P-site). The peptide bond formation results in the net loss of one water molecule, leaving a deacylated-tRNA in the P-site, and a nascent polypeptide chain one amino acid larger in the A-site. For the purpose of illustration, the figures used in the section show one amino acid being added to a peptidyl-tRNA with a growing peptide chain."
BMGC_PW0555,BMG_PW2866,,,"Telomeres are protein-DNA complexes at the ends of linear chromosomes that are important for genome stability. Telomeric DNA in humans, as in many eukaryotic organisms, consists of tandem repeats (Blackburn and Gall 1978; Moyzis et al. 1988; Meyne et al. 1989). The repeats at human telomeres are composed of TTAGGG sequences and stretch for several kilobase pairs. Another feature of telomeric DNA in many eukaryotes is a G-rich 3' single strand overhang, which in humans is estimated to be approximately 50-300 bases long (Makarov et al. 1997; Wright et al. 1997; Huffman et al. 2000). Telomeric DNA isolated from humans and several other organisms can form a lasso-type structure called a t-loop in which the 3' single-strand end is presumed to invade the double stranded telomeric DNA repeat tract (Griffith et al. 1999). Telomeric DNA is bound by multiple protein factors that play important roles in regulating telomere length and in protecting the chromosome end from recombination, non-homologous end-joining, DNA damage signaling, and unregulated nucleolytic attack (reviewed in de Lange 2005). DNA attrition can occur at telomeres, which can impact cell viability. Attrition can occur owing to the ""end-replication problem"", a consequence of the mechanism of lagging-strand synthesis (Watson 1972; Olovnikov 1973). Besides incomplete replication, nucleolytic processing also likely contributes to telomere attrition (Huffman et al. 2000). If telomeres become critically shortened, replicative senescence can result (Harley et al. 1990). Thus, in order to undergo multiple divisions, cells need a mechanism to replenish the sequence at their chromosome ends. The primary means for maintaining the sequence at chromosome ends in many eukaryotic organisms, including humans, is based on telomerase (Greider and Blackburn, 1985; Morin 1989). Telomerase is a ribonucleoprotein complex minimally composed of a conserved protein subunit containing a reverse transcriptase domain (telomerase reverse transcriptase, TERT) (Lingner et al. 1997; Nakamura et al. 1997) and a template-containing RNA (telomerase RNA component, TERC, TR, TER) (Greider and Blackburn, 1987; Feng et al 1995). Telomerase uses the RNA template to direct addition of multiple tandem repeats to the 3' G-rich single strand overhang. Besides extension by telomerase, maintenance of telomeric DNA involves additional activities, including C-strand synthesis, which fills in the opposing strand, and nucleolytic processing, which likely contributes to the generation of the 3' overhang."
BMGC_PW0556,BMG_PW2867,,,"Gap junctions are clusters of intercellular channels connecting adjacent cells and permitting the direct exchange of ions and small molecules between cells. These channels are composed of two hemichannels, or connexons, one located on each of the two neighboring cells. Each connexon is composed of 6 trans-membrane protein subunits of the connexin (Cx) family. A gap of approximately 3 nm remains between the adjacent cell membranes, but two connexons interact and dock head-to-head in the extra-cellular space forming a tightly sealed, double-membrane intercellular channel (see Segretain and Falk, 2004). The activity of these intercellular channels is regulated, particularly by intramolecular modifications such as phosphorylation which appears to regulate connexin turnover, gap junction assembly and the opening and closure (gating) of gap junction channels."
BMGC_PW0557,BMG_PW2868,,,"Mitochondrial biogenesis and remodeling occur in response to exercise and redox state (reviewed in Scarpulla et al. 2012, Handy and Loscalzo 2012, Piantadosi and Suliman 2012, Scarpulla 2011, Wenz et al. 2011, Bo et al. 2010, Jornayvaz and Shulman 2010, Ljubicic et al. 2010, Hock and Kralli 2009, Canto and Auwerx 2009, Lin 2009, Scarpulla 2008, Ventura-Clapier et al. 2008). It is hypothesized that calcium influx and energy depletion are the signals that initiate changes in gene expression leading to new mitochondrial proteins. Energy depletion causes a reduction in ATP and an increase in AMP which activates AMPK. AMPK in turn phosphorylates the coactivator PGC-1alpha (PPARGC1A), one of the master regulators of mitochondrial biosynthesis. Likewise, p38 MAPK is activated by muscle contraction (possibly via calcium and CaMKII) and phosphorylates PGC-1alpha. CaMKIV responds to intracellular calcium by phosphorylating CREB, which activates expression of PGC-1alpha. Deacetylation of PGC-1alpha by SIRT1 may also play a role in activation (Canto et al. 2009, Gurd et al. 2011), however Sirt11 deacetylation of Ppargc1a in mouse impacted genes related to glucose metabolism rather than mitochondrial biogenesis (Rodgers et al. 2005) and mice lacking SIRT1 in muscle had normal levels of mitochondrial biogenesis in response to exercise (Philp et al. 2011) so the role of deacetylation is not fully defined. PGC-1beta and PPRC appear to act similarly to PGC-1alpha but they have not been as well studied. Phosphorylated PGC-1alpha does not bind DNA directly but instead interacts with other transcription factors, notably NRF1 and NRF2 (via HCF1). NRF1 and NRF2 together with PGC-1alpha activate the transcription of nuclear-encoded, mitochondrially targeted proteins such as TFB2M, TFB1M, and TFAM."
BMGC_PW0558,BMG_PW2869,,,Transport of the SLBP independent Mature mRNA through the nuclear pore.
BMGC_PW0559,BMG_PW2870,,,Transport of U7 snRNP and stem-loop binding protein (SLBP) processed mRNA.
BMGC_PW0560,BMG_PW2871,,,"Transport of mRNA from the nucleus to the cytoplasm, where it is translated into protein, is highly selective and closely coupled to correct RNA processing."
BMGC_PW0561,BMG_PW2872,,,"Transport of mature mRNAs derived from intronless transcripts require some of the same protein complexes as mRNAs derived from intron containing complexes, including TAP and Aly/Ref. However a number of the splicing related factors are lacking from the intronless derived mRNAs, as they required no splicing."
BMGC_PW0562,BMG_PW2873,,,"Transport of mRNA from the nucleus to the cytoplasm, where it is translated into protein, is highly selective and closely coupled to correct RNA processing. This coupling is achieved by the nuclear pore complex, which recognizes and transports only completed mRNAs."
BMGC_PW0563,BMG_PW2874,,,"The matrix metalloproteinases (MMPs), previously known as matrixins, are classically known to be involved in the turnover of extracellular matrix (ECM) components. However, recent high throughput proteomics analyses have revealed that ~80% of MMP substrates are non-ECM proteins including cytokines, growth factor binding protiens, and receptors. It is now clear that MMPs regulate ECM turnover not only by cleaving ECM components, but also by the regulation of cell signalling, and that some MMPs are beneficial and may be drug anti-targets. Thus, MMPs have important roles in many processes including embryo development, morphogenesis, tissue homeostasis and remodeling. They are implicated in several diseases such as arthritis, periodontitis, glomerulonephritis, atherosclerosis, tissue ulceration, and cancer cell invasion and metastasis. All MMPs are synthesized as preproenzymes. Alternate splice forms are known, leading to nuclear localization of select MMPs. Most are secreted from the cell, or in the case of membrane type (MT) MMPs become plasma membrane associated, as inactive proenzymes. Their subsequent activation is a key regulatory step, with requirements specific to MMP subtype."
BMGC_PW0564,BMG_PW2875,,,"Of the 20-40 grams of bile salts released daily by the liver, all but approximately 0.5 grams are reabsorbed from the intestine, returned to the liver, and re-used. This recycling involves a series of transport processes: uptake by enterocytes mediated by ASBT (SLC10A2), traversal of the enterocyte cytosol mediated by ileal bile acid binding protein (I-BABP - FABP6), efflux from enterocytes mediated by MRP3 (ABCC3), travel through the portal blood as a complex with albumin, and uptake by hepatocytes mediated by Na+-taurocholate transporting protein (NTPC - SLC10A1) and, to a lesser extent by organic anion transporting proteins A, C, and 8 (OATPA - SLCO1A2, OATPC - SLCO1B1, and OATP-8 - SLCO1B3). Once returned to the hepatocyte cytosol, bile acids (generated in the intestine by the action of bacteria on secreted bile salts) are activated by conjugation with coenzyme A, then coupled to glycine or taurine, regenerating bile salts for re-export into the bile, mediated by the bile salt export pump, ABCB11 (Kullak-Ublick et al. 2004; Mihalik et al. 2002; Trauner and Boyer 2003). Unmodified bile salts returned to the hepatocyte cytosol can be re-exported by ABCB11 without further modification."
BMGC_PW0565,BMG_PW2876,,,"Xenobiotics and endogenous compounds containing carboxylate groups can be activated with coenzyme A to produce acyl-CoA thioesters and then conjugated with the amino groups of glycine or glutamine to form amide-linked conjugates. Clinically important substrates include benzoic acid, phenylacetic acid, and salicylic acid."
BMGC_PW0566,BMG_PW2877,,,"Gamma-carboxylation of a cluster of glutamate residues near the amino termini of thrombin, factor VII, factor IX, factor X, protein C, protein S, protein Z, and Gas 6 is required for these proteins to bind Ca++ and function efficiently in blood clotting. A single enzyme, vitamin K-dependent gamma-carboxylase, catalyzes the gamma-carboxylation of all eight proteins involved in clotting (Morris et al. 1995; Brenner et al. 1998; Spronk et al. 2000). In the carboxylation reaction, the enzyme binds its substrate protein via a sequence motif on the amino terminal side of the glutamate residues to be carboxylated (Furie et al. 1999), then processively carboxylates all glutamates in the cluster before releasing the substrate (Morris et al. 1995; Berkner 2000; Stenina et al. 2001). The reaction occurs in the endoplasmic reticulum (Bristol et al. 1996)."
BMGC_PW0567,BMG_PW2878,,,Gamma-carboxylated proteins are moved by anterograde transport from the endoplasmic reticulum to the Golgi apparatus (Kirchhausen 2000).
BMGC_PW0568,BMG_PW2879,,,"Furin is an endopeptidase localized to the Golgi membrane that cleaves many proteins on the carboxyterminal side of the sequence motif Arg-[any residue]-(Lys or Arg)-Arg (Jones et al. 1995; Leduc et al. 1992). In the case of gamma-carboxylated proteins, if this cleavage does not occur, the proteins are still secreted but do not function properly (Bristol et al. 1993; Lind et al. 1997; Wasley et al. 1993). The aminoterminal fragments, ""propeptides"", generated in this reaction have no known function; the carboxylated, cleaved proteins are delivered to the cell membrane or secreted from the cell."
BMGC_PW0569,BMG_PW2880,,,"A number of proteins, including eight required for normal blood clot formation and its regulation (Prothrombin (factor II), factor VII, factor IX, factor X, protein C, protein S, protein Z, and Gas6) share a sequence motif rich in glutamate residues near their amino termini. Carboxylation of the glutamate residues within this motif followed by removal of an aminoterminal propeptide is required for each of these proteins to function. These modifications occur as the proteins move through the endoplasmic reticulum and Golgi apparatus."
BMGC_PW0570,BMG_PW2881,,,"Z-DNA-binding protein-1 (ZBP1), also known as, DNA-dependent activator of IFN-regulatory factors (DAI) was reported to initiate innate immune responses in murine L929 cells upon stimulation by multiple types of exogenously added DNA (Takaoka A et al 2007). Human cytomegalovirus (HCMV) was shown to stimulate ZBP1-mediated induction of IRF3 in human foreskin (DeFilippis VR et al 2010). ZBP1 was also implicated in activation of NF-kappaB pathways in human embryonic kidney HEK293T cells (Kaiser WJ et al 2008, Rebsamen M et al 2009). However, the role and importance ofZBP1 as dsDNA sensor remain controversial, since knocking down ZBP1 expression in other human or murine cell types by siRNA had very little effect on cellular responses to cytosolic DNA, suggesting the presence of alternative pathway (Wang ZC et al 2008, Lippmann J et al 2008). Tissue-specific expression of human ZBP1 also suggests that ZBP1 may function in cell-type specific way (Rothenburg S et al 2002)."
BMGC_PW0571,BMG_PW2882,,,"Interferon regulatory factors (IRF) IRF-3 and IRF-7 are the major modulators of IFN gene expression in response to pathogenic molecules. The relative contribution of IRF3 and IRF7 depends on the signaling pathway that is activated. Type I IFN production in cytosolic DNA-sensing pathway is mediated predominantly by IRF3 and partially by IRF7, since DNA-stimulated IFN-beta and IFN-alpha4 mRNA induction was strongly inhibited in IRF3-deficient mouse embryonic fibroblasts (MEFs), while remained normal (IFN-beta) or reduced (IFN-alpha4) in IRF7-deficient MEFs (Takaoke A et al 2007). IRF3 activation in response to B-DNA stimulation occurs via its co-recruitment with serine/threonine kinase TANK-binding kinase 1 (TBK1) or inducible IkB kinase (IKKi/IKKepsilon) to the C-terminal region of DAI."
BMGC_PW0572,BMG_PW2883,,,"While the human body is very economical with sulfur amino acids (SAA), superfluous SAA are degraded via cysteine to toxic hydrogen sulfide which must be dealt with. The pathway to oxidize this gas is localized to mitochondria and is highly conserved, pointing back to a time when life was immersed in sulfide-rich waters. The pathway for sulfide oxidation consists of five reactions, one of which, the sulfur transfer from thiosulfate to glutathione, is still to be characterized fully. A mutation in one enzyme has been identified that is associated with ethylmalonyl encephalopathy and where tissue sulfide is elevated (Stipanuk & Ueki 2011)."
BMGC_PW0573,BMG_PW2884,,,"While in humans excess methionine is converted to homocysteine, homocysteine and its transsulfuration product cysteine can be degraded to several end products, two of which, taurine and hydrogen sulfide, have uses in other biological processes (Stipanuk & Ueki 2011)."
BMGC_PW0574,BMG_PW2885,,,"Transsulfuration is the interconversion of homocysteine and cysteine, and it fully takes place in bacteria and some plants and fungi. Animals however have only one direction of this bidirectional path, the synthesis of cysteine from homocysteine via cystathionine. Because excess cysteine is degraded to hydrogen sulfide, which is now known as a neuromodulator and smooth muscle relaxant, this pathway is also the main source of its production, which takes place in the cytosol, as well as in extracellular space (Dominy & Stipanuk 2004, Bearden et al. 2010)."
BMGC_PW0575,BMG_PW2887,,,"The life cycle of HIV-1 is divided into early and late phases, shown schematically in the figure. In the early phase, an HIV-1 virion binds to receptors and co-receptors on the human host cell surface (a), viral and host cell membranes fuse and the viral particle is uncoated (b), the viral genome is reverse transcribed and the viral preintegration complex (PIC) forms (c), the PIC is transported through the nuclear pore into the nucleoplasm (d), and the viral reverse transcript is integrated into a host cell chromosome (e). In the late phase, viral RNAs are transcribed from the integrated viral genome and processed to generate viral mRNAs and full-length viral genomic RNAs (f), the viral RNAs are exported through the nuclear pore into the cytosol (g), viral mRNAs are translated and the resulting viral proteins are post-translationally processed (h), core particles containing viral genomic RNA and proteins assemble at the host cell membrane and immature viral particles are released by budding. The released particles mature to become infectious (j), completing the cycle (Frankel and Young 1998; Miller and Bushman 1997). Most of the crucial concepts used to describe these processes were originally elucidated in studies of retroviruses associated with tumors in chickens, birds, and other animal model systems, and the rapid elucidation of the basic features of the HIV-1 life cycle was critically dependent on the intellectual framework provided by these earlier studies. This earlier work has been very well summarized (e.g., Weiss et al. 1984; Coffin et al. 1997); here for brevity and clarity we focus on experimental studies specific to the HIV-1 life cycle."
BMGC_PW0576,BMG_PW2888,,,"With the virus components precariously assembled on the inner leaflet of the plasma membrane, the host cell machinery is required for viral budding. The virus takes advantage of the host ESCRT pathway to terminate Gag polymerization and catalyze release. The ESCRT pathway is normally responsible for membrane fission that creates cytoplasm filled vesicular bodies. In this case HIV (and other viruses) take advantage of the ESCRT cellular machinery to facilitate virion budding from the host."
BMGC_PW0577,BMG_PW2890,,,"For retroviral DNA to direct production of progeny virions it must become covalently integrated into the host cell chromosome (reviewed in Coffin et al. 1997; Hansen et al. 1998). Analyses of mutants have identified the viral integrase coding region (part of the retroviral pol gene) as essential for the integration process (Donehower 1988; Donehower and Varmus 1984; Panganiban and Temin 1984; Quinn and Grandgenett 1988; Schwartzberg et al. 1984). Also essential are regions at the ends of the viral long terminal repeats (LTRs) that serve as recognition sites for integrase protein (Colicelli and Goff 1985, 1988; Panganiban and Temin 1983). The viral genomic RNA is reverse transcribed to form a linear double-stranded DNA molecule, the precursor to the integrated provirus (Brown et al. 1987, 1989; Fujiwara and Mizuuchi 1988). The provirus is colinear with unintegrated linear viral DNA (Dhar et al. 1980; Hughes et al. 1978) but differs from the reverse transcription product in that it is missing two bases from each end (Hughes et al. 1981). Flanking the integrated HIV provirus are direct repeats of the cellular DNA that are 5 base pairs in length (Vincent et al. 1990). This duplication of cellular sequences flanking the viral DNA is generated as a consequence of the integration mechanism (Coffin et al., 1997). Linear viral DNA is found in a complex with proteins in the cytoplasm of infected cells. These complexes (termed ""preintegration complexes"", PICs) can be isolated and have been shown to mediate integration of viral DNA into target DNA in vitro (Bowerman et al. 1989; Brown et al. 1987; Ellison et al. 1990; Farnet and Haseltine 1990, 1991). The development of in vitro assays with purified integrase has allowed its enzymatic functions to be elucidated. The provirus is formed by two reactions catalyzed by the viral integrase: terminal cleavage and strand transfer. Studies with purified integrase have shown that it is sufficient for both 3' end cleavage (Bushman and Craigie 1991; Craigie et al. 1990; Katzman et al. 1989; Sherman and Fyfe 1990) and joining of the viral DNA to the cellular chromosome or naked target DNA (Bushman et al. 1990; Craigie et al. 1990; Katz et al. 1990). HIV integrase catalyze the removal of two bases from the 3' end of each viral DNA strand, leaving recessed 3' hydroxyl groups (Brown et al. 1989; Fujiwara and Mizuuchi 1988; Roth et al. 1989; Sherman and Fyfe 1990). This terminal cleavage reaction is required for proper integration. It may allow the virus to create a standard end from viral DNA termini that can be heterogeneous due to the terminal transferase activity of reverse transcriptase (Miller et al. 1997; Patel and Preston 1994). In addition, the terminal cleavage step is coupled to the formation of a stable integrase-DNA complex (Ellison and Brown 1994; Vink et al. 1994). Following terminal cleavage, a recessed hydroxyl is exposed that immediately follows a CA dinucleotide. More internal LTR sites are also important for integration (Balakrishnan and Jonsson 1997; Bushman and Craigie 1990; Leavitt et al. 1992). After end processing, integrase catalyzes the covalent attachment of hydroxyl groups at the viral DNA termini to protruding 5' phosphoryl ends of the host cell DNA (Brown et al. 1987; Brown et al. 1989; Fujiwara and Mizuuchi 1988). The DNA cleavage and joining reactions involved in integration are shown in the figure below. Both the viral DNA 3' end cleavage and strand transfer reactions are mediated by single-step transesterification chemistry as shown by stereochemical analysis of reaction products (Engelman et al. 1991). Biochemical analysis of purified integrase revealed that it requires a divalent metal - either Mg2+ or Mn2+ - to carry out reactions with model substrates, that probably mediate the reaction chemistry (Bushman and Craigie 1991; Craigie et al. 1990; Katzman et al. 1989; Sherman and Fyfe 1990; Gao et al. 2004)."
BMGC_PW0578,BMG_PW2891,,,"In the early phase of HIV lifecycle, an active virion binds and enters a target cell mainly by specific interactions of the viral envelope proteins with host cell surface receptors. The virion core is uncoated to expose a viral nucleoprotein complex containing RNA and viral proteins. HIV RNA genome is reverse transcribed by the viral Reverse Transcriptase to form a cDNA copy, that gets inserted into host cell DNA. The viral Integrase enzyme is vital to carry out the integration of the viral cDNA into the host genome. The host DNA repair enzymes probably repair the breaks in DNA at the sites of integration."
BMGC_PW0579,BMG_PW2892,,,"The late phase of the HIV-1 life cycle includes the regulated expression of the HIV gene products and the assembly of viral particles. The assembly of viral particles will be covered in a later release of Reactome. HIV-1 gene expression is regulated by both cellular and viral proteins. Although the initial activation of the HIV-1 transcription is facilitated by cellular transcription factors including NF-kappa B (Nabel and Baltimore, 1987), this activation results in the production of primarily short transcripts (Kao et al., 1987). Expression of high levels of the full length HIV-1 transcript requires the function of the HIV-1 Tat protein which promotes elongation of the HIV-1 transcript (reviewed in Karn, 1999; Taube et al. 1999; Liou et al., 2004; Barboric and Peterlin 2005). The HIV-1 Rev protein is required post-transcriptionally for the expression of the late genes. Rev functions by promoting the nuclear export of unspliced and partially spliced transcripts that encode the major structural proteins Gag, Pol and Env, and the majority of the accessory proteins (Malim et al., 1989; reviewed in Pollard and Malim 1998 ."
BMGC_PW0580,BMG_PW2893,,,"The pericentriolar stacks of Golgi cisternae undergo extensive fragmentation and reorganization in mitosis. In mammalian cells, Golgi apparatus consists of stacked cisternae that are connected by tubules to form a ribbon-like structure in the perinuclear region, in vicinity of the centrosome. Reorganization of the Golgi apparatus during cell division allows both daughter cells to inherit this organelle, and may play additional roles in the organization of the mitotic spindle. First changes in the structure of the Golgi apparatus likely start in G2 and are subtle, involving unlinking of the Golgi ribbon into separate stacks. These changes are required for the entry of mammalian cells into mitosis (Sutterlin et al. 2002). This initial unlinking of the Golgi ribbon depends on GRASP proteins and on CTBP1 (BARS) protein, which induces the cleavage of the tubular membranes connecting the stacks (Hidalgo Carcedo et al. 2004, Colanzi et al. 2007), but the exact mechanism is not known. Activation of MEK1/2 also contributes to unlinking of the Golgi ribbon in G2 (Feinstein and Linstedt 2007). From prophase to metaphase, Golgi cisternae undergo extensive fragmentation that is a consequence of unstacking of Golgi cisternae and cessation of transport through Golgi. At least three mitotic kinases, CDK1, PLK1 and MEK1, regulate these changes. CDK1 in complex with cyclin B phosphorylates GOLGA2 (GM130) and GORASP1 (GRASP65), constituents of a cis-Golgi membrane complex (Lowe et al. 1998, Preisinger et al. 2005). Phosphorylation of GOLGA2 prevents binding of USO1 (p115), a protein localizing to the membrane of ER (endoplasmic reticulum) to Golgi transport vesicles and cis-Golgi, thereby impairing fusion of these vesicles with cis-Golgi cisternae and stopping ER to Golgi transport (Lowe et al. 1998, Seeman et al. 2000, Moyer et al. 2001). Phosphorylation of GORASP1 by CDK1 enables further phosphorylation of GORASP1 by PLK1 (Sutterlin et al. 2001, Preisinger et al. 2005). Phosphorylation of GORASP1 by CDK1 and PLK1 impairs stacking of Golgi cisternae by interfering with formation of GORASP1 trans-oligomers that would normally link the Golgi cisternae together (Wang et al. 2003, Wang et al. 2005, Sengupta and Linstedt 2010). In the median Golgi, GORASP2 (GRASP55), a protein that forms a complex with BLFZ1 (Golgin-45) and RAB2A GTPase and contributes to cisternae stacking and Golgi trafficking (Short et al. 2001), is also phosphorylated in mitosis. Phosphorylation of GORASP2 by MEK1/2-activated MAPK1 (ERK2) and/or MAPK3-3 (ERK1b in human, Erk1c in rat) contributes to Golgi unlinking in G2 and fragmentation of Golgi cisternae in mitotic prophase (Acharya et al. 1998, Jesch et al. 2001, Colanzi et al. 2003, Shaul and Seger 2006, Duran et al. 2008, Feinstein and Linstedt 2007, Feinstein and Linstedt 2008, Xiang and Wang 2010)."
BMGC_PW0581,BMG_PW2895,,,"The mature form of urokinase plasminogen activator receptor (uPAR) is attached to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor (Ploug et al. 1991). As nascent uPAR polypeptide moves into the lumen of the endoplasmic reticulum, it is attacked by a transamidase complex that cleaves the uPAR polypeptide after residue 305, releasing the carboxyterminal peptide of uPAR and replacing it with an acylated GPI moiety. In a second step, the GPI moiety is deacylated, yielding a uPAR-GPI conjugate that can be efficiently transported to the Golgi apparatus."
BMGC_PW0582,BMG_PW2896,,,"The global pandemic of Human Immunodeficiency Virus (HIV) infection has resulted in tens of millions of people infected by the virus and millions more affected. UNAIDS estimates around 40 million HIV/AIDS patients worldwide with 75% of them living in sub-Saharan Africa. The primary method of HIV infection is by sexual exposure while nonsexual HIV transmission also can occur through transfusion with contaminated blood products, injection drug use, occupational exposure,accidental needlesticks or mother-to-child transmission. HIV damages the immune system, leaving the infected person vulnerable to a variety of ""opportunistic"" infections arising from host immune impairment (Hare, 2004). HIV-1 and the less common HIV-2 belong to the family of retroviruses. HIV-1 contains a single-stranded RNA genome that is 9 kilobases in length and contains 9 genes that encode 15 different proteins. These proteins are classified as: structural proteins (Gag, Pol, and Env), regulatory proteins (Tat and Rev), and accessory proteins (Vpu, Vpr, Vif, and Nef) (Frankel and Young,1998). HIV infection cycle can be divided into two phases: 1. An Early phase consisting of early events occuring after HIV infection of a susceptible target cell and a 2. Late phase comprising the later events in the HIV-infected cell resulting in the assembly of new infectious virions. The section titled HIV lifecycle consists of annotations of events in these two phases. The virus has developed various molecular strategies to suppress the antiviral immune responses (innate, cellular and humoral) of the host. HIV-1 viral auxiliary proteins (Tat, Rev, Nef, Vif, Vpr and Vpu) play important roles in these host-pathogen interactions (Li et al.,2005). The section titled Host interactions of HIV factors highlights these complex post-infection processes."
BMGC_PW0583,BMG_PW2897,,,"Like all viruses, HIV-1 must co-opt the host cell macromolecular transport and processing machinery. HIV-1 Vpr and Rev proteins play key roles in this co-optation. Efficient HIV-1 replication likewise requires evasion of APOBEC3G-mediated mutagenesis of reverse transcripts, a process mediated by the viral Vif protein."
BMGC_PW0584,BMG_PW2898,,,"Glycosylphosphatidyl inositol (GPI) acts as a membrane anchor for many cell surface proteins. GPI is synthesized in the endoplasmic reticulum. In humans, a single pathway consisting of eleven reactions appears to be responsible for the synthesis of the major GPI species involved in membrane protein anchoring. As a nascent protein fated to become GPI-anchored moves into the lumen of the endoplasmic reticulum, it is attacked by a transamidase complex that cleaves it near its carboxy terminus and attaches an acylated GPI moiety. The GPI moiety is deacylated, yielding a protein-GPI conjugate that can be efficiently transported to the Golgi apparatus."
BMGC_PW0585,BMG_PW2899,,,"The re-entry of protons into the mitochondrial matrix through Complex V causes conformational changes which result in ATP synthesis. Complex V (ATP synthase) is composed of 3 parts; an F1 catalytic core (approx 5 subunits), an F0 membrane proton channel (approx 9 subunits) and two stalks linking F1 to F0. F1 contains three alpha subunits, three beta subunits, and one each of gamma, delta, and epsilon subunits. Each beta subunit contains an active site for ATP synthesis. F0 has at least 9 subunits (a-g, A6L and F6; see Lai et al., 2023; reviewed in Jonckheere et al., 2011). The mechanism of ATP synthesis by Complex V was predicted by Boyer et al in 1973: ADP and Pi bind to the enzyme resulting in a conformational change. ATP is then synthesized, still bound to the enzyme. Another change in the active site results in the release of free ATP into the matrix. The overall reaction is: ADP + Pi + H+ + nH+ (intermemb. space) = ATP + H2O + nH+ (matrix) Mutations in several ATP synthase subunits can lead to different types of mitochondrial complex V deficiency (MC5D; reviewed in Garone et al., 2022; Del Dotto et al., 2024)."
BMGC_PW0586,BMG_PW2901,,"Autophagy is a degradative pathway for the removal of cytoplasmic materials in eukaryotic cells, and is characterized by the formation of a double-membrane structure called the autophagosome, either in a housekeeping capacity or during stress and senescence. The process of autophagy could be divided into several stages: induction, vesicle nucleation, elongation and closure, and fusion and digestion. Most essential autophagic machineries are conserved throughout eukaryotes (see map04140 for animals and map04138 for fungi). This map is for other eukaryotes including plants and protists, where autophagy related genes (ATGs) play similar roles in the life cycle. However, autophagy has been relatively less studied in lower eukaryotes.","Macroautophagy (hereafter referred to as autophagy) acts as a buffer against starvation by liberating building materials and energy sources from cellular components. It has additional roles in embryonic development, removal of apoptotic cells or organelles, antigen presentation, protection against toxins and as a degradation route for aggregate-prone proteins and infectious agents. The dysregulation of autophagy is involved in several human diseases, for example, Crohn's disease, cancer and neurodegeneration (Ravikumar et al. 2010). Autophagy is highly conserved from yeast to humans; much of the machinery was first identified in yeast (see Klionsky et al. 2011). Initially, double-membraned cup-shaped structures called the isolation membrane or phagophore engulf portions of cytoplasm. The membranes fuse to form the autophagosome. In yeast cells, autophagosomes are formed at the phagophore assembly site (PAS) next to the vacuole. In mammals, autophagosomes appear throughout the cytoplasm then move along microtubules towards the microtubule-organising centre. This transport requires microtubules and the function of dynein motor proteins; depolymerization of microtubules or inhibition of dynein-dependent transport results in inhibition of autophagy (Kochl et al. 2006, Kimura et al. 2008). Autophagosomes fuse with lysosomes forming autolysosomes whose contents are degraded by lysosomal hydrolases (Mizushima et al. 2011). The origins of the autophagosomal membrane and the incorporation of existing membrane material have been extensively debated. The endoplasmic reticulum (ER), mitochondria, mitochondria-associated ER membranes (MAMs), the Golgi, the plasma membrane and recycling endosomes have all been implicated in the nucleation of the isolation membrane and subsequent growth of the membrane (Lamb et al. 2013). Recently 3D tomographic imaging of isolation membranes has shown the cup-shaped isolation membrane tightly sandwiched between two sheets of ER and physically connected to the ER through a narrow membrane tube (Hayashi-Nishino et al. 2009, Yla-Anttila et al. 2009). This suggests that isolation membrane formation and elongation are guided by adjacent ER sheets, supporting the now prevalent 'ER cradle' model, which suggests that the isolation membrane arises from the ER (Hayashi-Nishino et al. 2009, Shibutani & Yoshimori 2014). Autophagy is tightly regulated. The induction of autophagy in response to starvation is partly mediated by inactivation of the mammalian target of rapamycin (mTOR) (Noda & Ohsumi 1998) and activation of Jun N-terminal kinase (JNK), while energy loss induces autophagy by activation of AMP kinase (AMPK). Other pathways regulating autophagy are regulated by calcium, cyclic AMP, calpains and the inositol trisphosphate (IP3) receptor (Rubinsztein et al. 2012). In mammals, two complexes cooperatively produce the isolation membrane. The ULK complex consists of ULK1/2, ATG13, (FIP200) and ATG101 (Alers et al. 2012). The PIK3C3-containing Beclin-1 complex consists of PIK3C3 (Vps34), BECN1 (Beclin-1, Atg6), PIK3R4 (p150, Vps15) and ATG14 (Barkor) (Matsunaga et al. 2009, Zhong et al. 2009). A similar complex where ATG14 is replaced by UVRAG functions later in autophagosome maturation and endocytic traffic (Itakura et al. 2008, Liang et al. 2008). Binding of KIAA0226 to this complex negatively regulates the maturation process (Matsunaga et al. 2009). The ULK and Beclin-1 complexes are recruited to specific autophagosome nucleation regions where they stimulate phosphatidylinositol-3-phosphate (PI3P) production and facilitate the elongation and initial membrane curvature of the phagophore membrane (Carlsson & Simonsen 2015). The ULK complex is considered the most upstream component of the mammalian autophagy pathway (Itakura & Mizushima 2010), acting as an integrator of the autophagy signals downstream of mTORC1. It is not fully understood how ULK1 is modulated in response to environmental cues. Phosphorylation plays an essential role (Dunlop & Tee 2013) but it is not clear how phosphorylation regulates ULK1 activities (Ravikumar et al. 2010). ULK1 kinase activity is required for autophagy, but the substrate(s) of ULK1 that mediate its autophagic function are not certain. ULK1 may also have kinase-independent functions in autophagy (Wong et al. 2013). PIK3C3 (Vps34) is a class III phosphatidylinositol 3-kinase that produces PI3P. It is essential for the early stages of autophagy and colocalizes strongly with early autophagosome markers (Axe et al. 2008). BECN1 binds several further proteins that affect autophagosome formation. Partners that induce autophagy include AMBRA1 (Fimia et al. 2007), UVRAG (Liang et al. 2006) and SH3GLB1 (Takahashi et al. 2007). Binding of BCL2 or BCL2L1 (Bcl-xL) inhibit autophagy (Pattingre et al. 2005, Ciechomska et al. 2009). The inositol 1,4,5-trisphosphate receptor complex that binds BCL2 also interacts with BECN1, inhibiting autophagy (Vincencio et al. 2009). CISD2 (Nutrient-deprivation autophagy factor-1, NAF1), a component in the IP3R complex, interacts with BCL2 at the ER and stabilizes the BCL2-BECN1 interaction (Chang et al. 2010). Starvation leads to activation of c-Jun NH2-terminal kinase-1 (JNK1), which results in the phosphorylation of BCL2 and BCL2L1, which release their binding to BECN1 and thus induces autophagosome formation (Wei et al. 2008). AMBRA1 can simultaneously bind dynein and the Beclin-1 complex. During nutrient starvation, AMBRA1 is phosphorylated in a ULK1-dependent manner (Di Bartolomeo et al. 2010). This phosphorylation releases AMBRA1-associated Beclin-1 complexes from dynein and the microtubule network, freeing the complex to translocate to autophagy initiation sites (Di Bartolomeo et al. 2010). A characteristic of this early phase of autophagosome formation is the formation of PI3P-enriched ER-associated structures called omegasomes (Axe et al. 2008) or cradles (Hayashi-Nishino et al. 2009). Omegasomes appear to concentrate at or near the connected mitochondria-associated ER membrane (Hamasaki et al. 2013). However, the phagophore also can incorporate existing material from other membrane sources such as ER exit sites (ERES), the ER-Golgi intermediate compartment (ERGIC), the Golgi, the plasma membrane and recycling endosomes (Carlsson & Simonsen 2015). Omegasomes lead to the formation of the isolation membrane or phagophore, which is thought to form de novo by an unknown mechanism (Simonsen & Stenmark 2008, Roberts & Ktistakis 2013). Phagophore expansion is probably mediated by membrane uptake from endomembranes and semi-autonomous organelles (Lamb et al. 2013, Shibutani & Yoshimori 2014). ATG9 is a direct target of ULK1. In nutrient-rich conditions mammalian ATG9 is localized to the trans-Golgi network and endosomes (including early, late and recycling endosomes), whereas under starvation conditions it is localized to autophagosomes, in a process that is dependent on ULK1 (Young et al. 2006). ATG9 is believed to play a role in the delivery of vesicles derived from existing membranes to the expanding phagophore (Lamb et al. 2013). Yeast Atg9 forms a complex with Atg2 and Atg18 (Reggiori et al. 2004). PI3P produced at the initiation site is sensed by WIPI2b, the mammalian homologue of Atg18 (Polson et al. 2010). WIPI2b then recruits Atg16L1 (Dooley et al. 2014). There are four WIPI proteins in mammalian cells (Proikas-Cezanne et al. 2015). They are all likely bind PI3P and be recruited to membranes but the function of WIPI1, 3 and 4 in autophagy is not yet clear. WIPI4 (WDR45) has been shown to bind Atg2 and to be involved in lipid droplet formation (Velikkakath et al. 2012); mutations in WIPI4 have been shown to cause a neurodegenerative disease (Saitsu et al. 2013). The elongation of the membrane that will become the autophagosome is regulated by two ubiquitination-like reactions. First, the ubiquitin-like molecule ATG12 is conjugated to ATG5 by ATG7, which acts as an E1-like activating enzyme, and ATG10, which has a role similar to an E2 ubiquitin-conjugating enzyme. The ATG5:ATG12 complex then interacts non-covalently with ATG16L1. This complex associates with the forming autophagosome but dissociates from completed autophagosomes (Geng & Klionski 2008). The second ubiquitin-like reaction involves the conjugation of ubiquitin-like molecules of the LC3 family (Weidberg et al. 2010). LC3 proteins are conjugated through their C-terminal glycine residues with PE by the E1-like ATG7 and E2-like ATG3. This allows LC3 proteins to associate with the autophagosome membrane. The ATG12:ATG5:ATG16L1 complex (Mizushima et al., 2011) acts as an E3 like enzyme for the conjugation of LC3 family proteins (mammalian homologues of yeast Atg8) to phosphatidylethanolamine (PE) (Hanada et al. 2007, Fujita et al. 2008). LC3 PE can be deconjugated by the protease ATG4 (Li et al. 2011, 2012). ATG4 is also responsible for priming LC3 proteins by cleaving the C terminus to expose a glycine residue (Kirisako et al, 2000, Scherz Shouval et al. 2007). LC3 proteins remain associated with autophagosomes until they fuse with lysosomes. The LC3-like proteins inside the resulting autolysosomes are degraded, while those on the cytoplasmic surface are delipidated and recycled. ATG5:ATG12:ATG16L1-positive LC3-negative vesicles represent pre-autophagosomal structures (pre-phagophores and possibly early phagophores), ATG5:ATG12:ATG16L1-positive LC3-positive structures can be considered to be phagophores, and ATG5:ATG12:ATG16L1-negative LC3-positive vesicles can be regarded as mature autophagosomes (Tandia et al. 2011). Phagophore expansion is probably mediated by membrane uptake from endomembranes as well as from semiautonomous organelles (Lamb et al. 2013, Shibutani & Yoshimori 2014). The mechanisms involved in the closure of the phagophore membrane are poorly understood. As the phagophore is a double-membraned structure, its closure involves the fusion of a narrow opening, a process that is distinct from other membrane fusion events (Carlsson & Simonsen 2015). The topology of the phagophore is similar to that of cytokinesis, viral budding or multivesicular body (MVB) formation. These processes rely on the Endosomal Sorting Complex Required for Transport (ESCRT) (Rusten et al. 2012). ESCRT and associated proteins facilitate membrane budding away from the cytosol and subsequent cleavage of the bud neck (Hurley & Hanson 2010). Several studies have shown that depletion of ESCRT subunits or the regulatory ATPase Vps4 causes an accumulation of autophagosomes (Filimonenko et al. 2007, Rusten et al. 2007) but it is not clear whether ESCRTs are required for autophagosome closure or for autophagosome to endosome fusion. UVRAG is also involved in the maturation step, recruiting proteins that bring about membrane fusion such as the class C Vps proteins, which activate Rab7 thereby promoting fusion with late endosomes and lysosomes (Liang et al. 2008)."
BMGC_PW0587,BMG_PW2904,,"Glucagon is conventionally regarded as a counterregulatory hormone for insulin and plays a critical anti-hypoglycemic role by maintaining glucose homeostasis in both animals and humans. To increase blood glucose, glucagon promotes hepatic glucose output by increasing glycogenolysis and gluconeogenesis and by decreasing glycogenesis and glycolysis in a concerted fashion via multiple mechanisms. Glucagon also stimulates hepatic mitochondrial beta-oxidation to supply energy for glucose production. Glucagon performs its main effect via activation of adenylate cyclase. The adenylate-cyclase-derived cAMP activates protein kinase A (PKA), which then phosphorylates downstream targets, such as cAMP response element binding protein (CREB) and the bifunctional enzyme 6-phosphofructo-2-kinase/ fructose-2,6-bisphosphatase (one of the isoforms being PFK/FBPase 1, encoded by PFKFB1).","Glucagon and insulin are peptide hormones released from the pancreas into the blood, that normally act in complementary fashion to stabilize blood glucose concentration. When blood glucose levels rise, insulin release stimulates glucose uptake from the blood, glucose breakdown (glycolysis), and glucose storage as glycogen. When blood glucose levels fall, glucagon release stimulates glycogen breakdown and de novo glucose synthesis (gluconeogenesis), while inhibiting glycolysis and glycogen synthesis. At a molecular level, the binding of glucagon to the extracellular face of its receptor causes conformational changes in the receptor that allow the dissociation and activation of subunits Gs and Gq. The activation of Gq leads to the activation of phospholipase C, production of inositol 1,4,5-triphosphate, and subsequent release of intracellular calcium. The activation of Gs leads to activation of adenylate cyclase, an increase in intracellular cAMP levels, and activation of protein kinase A (PKA). Active PKA phosphorylates key enzymes of glycogenolysis, glycogenesis, gluconeogenesis, and glycolysis, modifying their activities. These signal transduction events, and some of their downstream consequences, are illustrated below (adapted from Jiang and Zhang, 2003)."
BMGC_PW0588,BMG_PW2905,,,"A number of inactive tetrameric PKA holoenzymes are produced by the combination of homo- or heterodimers of the different regulatory subunits associated with two catalytic subunits. When cAMP binds to two specific binding sites on the regulatory subunits, these undergo a conformational change that causes the dissociation of a dimer of regulatory subunits bound to four cAMP from two monomeric, catalytically active PKA subunits."
BMGC_PW0589,BMG_PW2906,,,"AMP-activated protein kinase (AMPK) is a sensor of cellular energy levels. A high cellular ratio of AMP:ATP triggers the phosphorylation and activation of AMPK. Activated AMPK in turn phosphorylates a wide array of target proteins, as shown in the figure below (reproduced from (Hardie et al. 2003), with the permission of D.G. Hardie). These targets include ChREBP (Carbohydrate Response Element Binding Protein), whose inactivation by phosphorylation reduces transcription of key enzymes of the glycolytic and lipogenic pathways."
BMGC_PW0590,BMG_PW2907,,,"Many hormones that affect individual physiological processes including the regulation of appetite, absorption, transport, and oxidation of foodstuffs influence energy metabolism pathways. While insulin mediates the storage of excess nutrients, glucagon is involved in the mobilization of energy resources in response to low blood glucose levels, principally by stimulating hepatic glucose output. Small doses of glucagon are sufficient to induce significant glucose elevations. These hormone-driven regulatory pathways enable the body to sense and respond to changed amounts of nutrients in the blood and demands for energy. Glucagon and Insulin act through various metabolites and enzymes that target specific steps in metabolic pathways for sugar and fatty acids. The processes responsible for the long-term control of fat synthesis and short-term control of glycolysis by key metabolic products and enzymes are annotated in this module as seven specific pathways: Pathway 1. Regulation of insulin secretion. Pathway 2. Glucagon signalling in metabolic pathways: In response to low blood glucose, pancreatic alpha-cells release glucagon. The binding of glucagon to its receptor results in increased cAMP synthesis, and Protein Kinase A (PKA) activation. Pathway 3. PKA mediated phosphorylation:PKA phosphorylates key enzymes, e.g., 6-Phosphofructo-2-kinase /Fructose-2,6-bisphosphatase (PF2K-Pase) at serine 36, and regulatory proteins, e.g., Carbohydrate Response Element Binding Protein (ChREBP) at serine 196 and threonine 666. In brief, the binding of insulin to its receptor leads to increased protein phosphatase activity and to hydrolysis of cAMP by cAMP phosphodiesterase. These events counteract the regulatory effects of glucagon. Pathway 4: Insulin stimulates increased synthesis of Xylulose-5-phosphate (Xy-5-P). Activation of the insulin receptor results indirectly in increased Xy-5-P synthesis from Glyceraldehyde-3-phosphate and Fructose-6-phosphate. Xy-5-P, a metabolite of the pentose phosphate pathway, stimulates protein phosphatase PP2A. Pathway 5: AMP Kinase (AMPK) mediated response to high AMP:ATP ratio: In response to diet with high fat content or low energy levels, the cytosolic AMP:ATP ratio is increased. AMP triggers a complicated cascade of events. In this module we have annotated only the phosphorylation of ChREBP by AMPK at serine 568, which inactivates this transcription factor. Pathway 6: Dephosphorylation of key metabolic factors by PP2A: Xy-5-P activated PP2A efficiently dephosphorylates phosphorylated PF2K-Pase resulting in the higher output of F-2,6-P2 that enhances PFK activity in the glycolytic pathway. PP2A also dephosphorylates (and thus activates) cytosolic and nuclear ChREBP. Pathway 7: Transcriptional activation of metabolic genes by ChREBP: Dephosphorylated ChREBP activates the transcription of genes involved in glucose metabolism such as pyruvate kinase, and lipogenic genes such as acetyl-CoA carboxylase, fatty acid synthetase, acyl CoA synthase and glycerol phosphate acyl transferase."
BMGC_PW0591,BMG_PW2909,,,"ChREBP (Carbohydrate Response Element Binding Protein) is a large multidomain protein containing a nuclear localization signal near its amino terminus, polyproline domains, a basic helix-loop-helix-leucine zipper domain, and a leucine-zipper-like domain (Uyeda et al., 2002). Its dephosphorylation in response to molecular signals associated with the well-fed state allows it to enter the nucleus, interact with MLX protein, and bind to ChRE DNA sequence motifs near Acetyl-CoA carboxylase, Fatty acid synthase, and Pyruvate kinase (L isoform) genes (Ishi et al.2004). This sequence of events is outlined schematically in the picture below (adapted from Kawaguchi et al. (2001) - copyright (2001) National Academy of Sciences, U.S.A.)."
BMGC_PW0592,BMG_PW2910,,,"A member of the PP2A family of phosphatases dephosphorylates both cytosolic and nuclear forms of ChREBP (Carbohydrate Response Element Binding Protein). In the nucleus, dephosphorylated ChREBP complexes with MLX protein and binds to ChRE sequence elements in chromosomal DNA, activating transcription of genes involved in glycolysis and lipogenesis. The phosphatase is activated by Xylulose-5-phosphate, an intermediate of the pentose phosphate pathway (Kabashima et al. 2003). The rat enzyme has been purified to homogeneity and shown by partial amino acid sequence analysis to differ from previously described PP2A phosphatases (Nishimura and Uyeda 1995) - the human enzyme has not been characterized."
BMGC_PW0593,BMG_PW2911,,,"Keratan sulfate (KS) (a glycosaminoglycan, GAG) is a linear polysaccharide that consists of the repeating disaccharide unit GlcNAc-Gal (N-acetylglucosamine-galactose). KS can perform a structural function and is found in bone, cartilage and the cornea. In joints, it also acts as a shock absorber due to its highly hydrated nature. There are several classes of KS, KSI, II and III. KSI is N-linked to asparagine (Asn) residues in the core protein and is predominantly found in the cornea. KSII is O-linked to serine (Ser) or Thr (threonine) residues in the core protein and is found predominantly in cartilage linked to the protein aggrecan, forming the most abundant proteoglycan in cartilage. A third class of KS, KSIII, are proteoglycans in the brain. KSIII chains are linked to Ser/Thr residues in the core protein via mannose (Funderburgh 2000, Funderburgh 2002). Normally, the body degrades GAGs as a natural turnover. Defects in the degradative enzymes cause the autosomal recessive mucopolysaccharide storage disease Morquio's syndrome (also called mucopolysaccharidosis IV). This involves the build up of KS in lysosomes, manifesting clinically as skeletal, dental and corneal abnormalities (Tomatsu et al. 2005)."
BMGC_PW0594,BMG_PW2912,,,"The acronym HS-GAG is used to describe both heparin and heparan sulfate. HS-GAG is a member of the glycosaminoglycan family and consists of a variably sulfated repeating disaccharide unit, the most common one (50% of the total) being glucuronic acid (GlcA) linked to N-acetylglucosamine (GlcNAc). GlcA can be epimerized to iduronic acid. Higher degrees of sulfation and iduronic acid content in the polysaccharide chain confers the name heparin rather than heparan sulfate to the chain. HS-GAG, like the majority of GAGs in the body, are linked to core proteins, forming proteoglycans (mucopolysaccharides). Two or three HS-GAG chains attach to a core protein on the cell surface or in the extracellular matrix (Sasisekharan & Venkataraman 2000). HS-GAG bound to a core protein can regulate many biological processes such as angiogenesis, blood coagulation and tumour metastasis (Stringer & Gallagher 1997, Tumova et al. 2000). Degradation of HS-GAG is required to maintain a natural turnover of GAGs. Defects in the degradative enzymes result in lysosomal storage diseases, where GAGs build up rather than being broken down and having pathological effects (Ballabio & Gieselmann 2009)."
BMGC_PW0595,BMG_PW2913,,,"After translation, many newly formed proteins undergo further covalent modifications that alter their functional properties and that are essentially irreversible under physiological conditions in the body. These modifications include the vitamin K-dependent attachment of carboxyl groups to glutamate residues and the conversion of a lysine residue in eIF5A to hypusine, the conversion of a histidine residue in EEF to diphthamide, and the hydrxylation of various amino acid side chains."
BMGC_PW0596,BMG_PW2914,,,"The pathway ""Signaling by EGFR in Cancer"" shows signaling by constitutively active EGFR cancer variants in the context of ""Signaling by EGFR"", allowing users to compare cancer events with the wild-type EGFR events. Red lines emphasize cancer related events and physical entities, while wild-type entities and events are shaded. Please refer to ""Signaling by Ligand-Responsive EGFR Variants in Cancer"", ""Signaling by EGFRvIII in Cancer"" and ""Signaling by Overexpressed Wild-Type EGFR in Cancer"" for detailed pathway summations."
BMGC_PW0597,BMG_PW2915,,,"Adenylate cyclase catalyses the synthesis of cyclic AMP (cAMP) from ATP. In the absence of cAMP, protein kinase A (PKA) exists as inactive tetramers of two catalytic subunits and two regulatory subunits. cAMP binding to PKA tetramers causes them to dissociate and release their catalytic subunits as active monomers. Four isoforms of the regulatory subunit are known, that differ in their tissue specificity and functional characteristics, but the specific isoform activated in response to glucagon signaling has not yet been identified."
BMGC_PW0598,BMG_PW2918,,,"The formation of 2-LTR circles requires the action of the cellular non-homologous DNA end-joining pathway. Specifically the cellular Ku, XRCC4 and ligase IV proteins are needed. Evidence for this is provided by the observation that cells mutant in these functions do not support detectable formation of 2-LTR circles, though integration and formation of 1-LTR circles are mostly normal. The reaction takes place in the nucleus, and formation of 2-LTR circles has been used as a surrogate assay for nuclear transport. It has also been suggested that the NHEJ system affects the toxicity of retroviral infection."
BMGC_PW0599,BMG_PW2919,,,"The maximal virulence of HIV-1 requires Nef, a virally encoded peripheral membrane protein. Nef binds to the adaptor protein (AP) complexes of coated vesicles, inducing an expansion of the endosomal compartment and altering the surface expression of cellular proteins including CD4 and class I major histocompatibility complex. Nef affects the cell surface expression of several cellular proteins. It down-regulates CD4, CD8, CD28, and major histocompatibility complex class I and class II proteins, but upregulates the invariant chain of MHC II (CD74). To modulate cell surface receptor expression, Nef utilizes several strategies, linked to distinct regions within the Nef protein. Since all these receptors are essential for proper functions of the immune system, modulation of their surface expression by Nef has profound effects on anti-HIV immune responses. Down-regulation of MHC I protects HIV-infected cells from host CTL response, whereas down-modulation of CD28 and CD4 probably limits the adhesion of a Nef-expressing T cell to the antigen-presenting cell, thus promoting the movement of HIV-infected cells into circulation and the spread of the virus."
BMGC_PW0600,BMG_PW2921,,,Down-regulation of MHC class I involves Nef-mediated connection in the endosomes between MHC-I's cytoplasmic tail and the phosphofurin acidic cluster sorting protein-1 (PACS-1)-dependent protein-sorting pathway. Down-regulation of MHC I protects HIV-infected cells from host CTL response.
BMGC_PW0601,BMG_PW2922,,,"Nef interferes with cellular signal transduction pathways in a number of ways. Nef is associated with lipid rafts through its amino-terminal myristoylation and a proline-rich SH3-binding domain. These cholesterol-rich membrane microdomains appear to concentrate potent signaling mediators. Nef was found to complex with and activate serine/threonine protein kinase PAK-2, which may contribute to activation of infected cells. In vitro, HIV-infected T cells produce enhanced levels of interleukin-2 during activation. When expressed in macrophages, Nef intersects the CD40L signaling pathway inducing secretion of chemokines and other factors that attract resting T cells and promote their infection by HIV."
BMGC_PW0602,BMG_PW2923,,,"The HIV-1 Nef protein is a 27-kDa myristoylated protein that is abundantly produced during the early phase of viral replication cycle. It is highly conserved in all primate lentiviruses, suggesting that its function is essential for survival of these pathogens. The protein name ""Nef"" was derived from early reports of its negative effect on viral replication, thus 'negative factor' or Nef. Subsequently it has been demonstrated that Nef plays an important role in several steps of HIV replication. In addition, it appears to be a critical pathogenic factor, as Nef-deficient SIV and HIV are significantly less pathogenic than the wild-type viruses, whereas Nef-transgenic mice show many features characteristic to HIV disease. The role of Nef in HIV-1 replication and disease pathogenesis is determined by at least four independent activities of this protein. Nef affects the cell surface expression of several cellular proteins, interferes with cellular signal transduction pathways, enhances virion infectivity and viral replication, and regulates cholesterol trafficking in HIV-infected cells."
BMGC_PW0603,BMG_PW2924,,,"The HIV-1 genome contains 9 genes encoded by a single transcript. In order for the virus to replicate, unspliced, singly-spliced and fully spliced viral mRNA must be exported from the nucleus. The HIV-1 mRNA splice sites are inefficient resulting it the accumulation of a pool of incompletely spliced RNAs (Staffa and Cochrane, 1994). In the early stages of the viral life cycle, or in the absence of the viral Rev protein, completely spliced viral mRNA which encode the regulatory proteins Tat, Nef and Rev are exported from the nucleus while the incompletely spliced structural protein encoding transcripts are held within the nucleus by cellular proteins that normally function in preventing the nuclear export of cellular pre-mRNA. Export of both unspliced and partially spliced mRNA is mediated by the viral protein Rev which is recruited, along with cellular cofactors, to the Rev Response Element (RRE) within the HIV-1 mRNA sequence (Malim et al., 1990; Fischer et al., 1994). The cellular hRIP protein is essential for correct Rev-mediated export of viral RNAs to the cytoplasm (Sanchez-Velar et al., 2004; Yu et al., 2005)."
BMGC_PW0604,BMG_PW2925,,,"The biosynthesis of collagen is a multistep process. Collagen propeptides are cotranslationally translocated into the ER lumen. Propeptides undergo a number of post-translational modifications. Proline and lysine residues may be hydroxylated by prolyl 3-, prolyl 4- and lysyl hydroxylases. 4-hydroxyproline is essential for intramolecular hydrogen bonding and stability of the triple helical collagenous domain. In fibril forming collagens approximately 50% of prolines are 4-hydroxylated; the extent of this and of 3-hydroxyproline and lysine hydroxylation varies between tissues and collagen types (Kivirikko et al. 1972, 1992). Hydroxylysine molecules can form cross-links between collagen molecules in fibrils, and are sites for glycosyl- and galactosylation. Collagen peptides all have non-collagenous domains; collagens within the subclasses have common chain structures. These non-collagenous domains have regulatory functions; some are biologically active when cleaved from the main peptide chain. Fibrillar collagens all have a large triple helical domain (COL1) bordered by N and C terminal extensions, called the N and C propeptides, which are cleaved prior to formation of the collagen fibril. The C propeptide, also called the NC1 domain, is highly conserved. It directs chain association during intracellular assembly of the procollagen molecule from three collagen propeptide alpha chains (Hulmes 2002). The N-propeptide has a short linker (NC2) connecting the main triple helix to a short minor one (COL2) and a globular N-terminal region NC3. NC3 domains are variable both in size and the domains they contain. Collagen propeptides typically undergo a number of post-translational modifications. Proline and lysine residues are hydroxylated by prolyl 3-, prolyl 4- and lysyl hydroxylases. 4-hydroxyproline is essential for intramolecular hydrogen bonding and stability of the triple helical collagenous domain. Prolyl 4-hydroxylase may also have a role in alpha chain association as no association of the C-propeptides of type XII collagen was seen in the presence of prolyl 4-hydroxylase inhibitors (Mazzorana et al. 1993, 1996). In fibril forming collagens approximately 50% of prolines are 4-hydroxylated; the extent of this is species dependent, lower hydroxylation correlating with lower ambient temperature and thermal stability (Cohen-Solal et al. 1986, Notbohm et al. 1992). Similarly the extent of 3-hydroxyproline and lysine hydroxylation varies between tissues and collagen types (Kivirikko et al. 1992). Hydroxylysine molecules can form cross-links between collagen molecules in fibrils, and are sites for glycosyl- and galactosylation. Collagen molecules fold and assemble through a series of distinct intermediates (Bulleid 1996). Individual collagen polypeptide chains are translocated co-translationally across the membrane of the endoplasmic reticulum (ER). Intra-chain disulfide bonds are formed within the N-propeptide, and hydroxylation of proline and lysine residues occurs within the triple helical domain (Kivirikko et al. 1992). When the peptide chain is fully translocated into the ER lumen the C-propeptide folds, the conformation being stabilized by intra-chain disulfide bonds (Doege and Fessler 1986). Pro alpha-chains associate via the C-propeptides (Byers et al. 1975, Bachinger et al. 1978), or NC2 domains for FACIT family collagens (Boudko et al. 2008) to form an initial trimer which can be stabilized by the formation of inter-chain disulfide bonds (Schofield et al. 1974, Olsen et al. 1976), though these are not a prerequisite for further folding (Bulleid et al. 1996). The triple helix then nucleates and folds in a C- to N- direction. The association of the individual chains and subsequent triple helix formation are distinct steps (Bachinger et al. 1980). The N-propeptides associate and in some cases form inter-chain disulfide bonds (Bruckner et al., 1978). Procollagen is released via carriers into the exracellular space (Canty & Kadler 2005). Fibrillar procollagens undergo removal of the C- and N-propeptides by procollagen C and N proteinases respectively, both Zn2+ dependent metalloproteinases. Propeptide processing is a required step for normal collagen I and III fibril formation, but collagens can retain some or all of their non-collagenous propeptides. Retained collagen type V and XI N-propeptides contribute to the control of fibril growth by sterically limiting lateral molecule addition (Fichard et al. 1995). Processed fibrillar procollagen is termed tropocollagen, which is considered to be the unit of higher order fibrils and fibres. Tropocollagens of the fibril forming collagens I, II, III, V and XI sponteneously aggregate in vitro in a manner that has been compared with crystallization, commencing with a nucleation event followed by subsequent organized aggregation (Silver et al. 1992, Prockop & Fertala 1998). Fibril formation is stabilized by lysyl oxidase catalyzed crosslinks between adjacent molecules (Siegel & Fu 1976)."
BMGC_PW0605,BMG_PW2928,,,"Phosphorylation of TSC2 by PKB disrupts TSC1/TSC2 heterodimer formation (Hay & Sonenberg 2004). TSC2 function is affected in at least two ways: first, phosphorylation decreases the activity of TSC2; second, phosphorylation destabilizes the TSC2 protein. This destabilization is achieved by disrupting complex formation between TSC1 and TSC2 and inducing ubiquination of the free TSC2 (Inoki et al. 2002). Phosphorylation of complexed TSC2 by PKB may result in the dissociation of the TSC1:TSC2 complex (Proud 2002)."
BMGC_PW0606,BMG_PW2929,,,"Sterol regulatory element binding proteins (SREBPs, SREBFs) respond to low cholesterol concentrations by transiting to the nucleus and activating genes involved in cholesterol and lipid biosynthesis (reviewed in Brown and Goldstein 2009, Osborne and Espenshade 2009, Weber et al. 2004). Newly synthesized SREBPs are transmembrane proteins that bind SCAP in the endoplasmic reticulum (ER) membrane. SCAP binds cholesterol which causes a conformational change that allows SCAP to interact with INSIG, retaining the SCAP:SREBP complex in the ER. INSIG binds oxysterols, which cause INSIG to bind SCAP and retain SCAP:SREBP in the endoplasmic reticulum. In low cholesterol (below about 5 mol%) SCAP no longer interacts with cholesterol or INSIG and binds Sec24 of the CopII coat complex instead. Thus SCAP:SREBP transits with the CopII complex from the ER to the Golgi. In the Golgi SREBP is cleaved by S1P and then by S2P, releasing the N-terminal fragment of SREBP into the cytosol. The N-terminal fragment is imported to the nucleus by importin-beta and then acts with other factors, such as SP1 and NF-Y, to activate transcription of target genes. Targets of SREBP include the genes encoding all enzymes of cholesterol biosynthesis and several genes involved in lipogenesis. SREBP2 most strongly activates cholesterol biosynthesis while SREBP1C most strongly activates lipogenesis."
BMGC_PW0607,BMG_PW2931,,,"At the plasma membrane, subsequent phosphorylation of phosphatidylinositol 4-phosphate (PI4P) produces phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) while the actions of various other kinases and phosphatases produces phosphatidylinositol 3-phosphate (PI3P), phosphatidylinositol 5-phosphate (PI5P), phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2), and phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) (Zhang et al. 1997, Gurung et al. 2003, Guo et al. 1999, Vanhaesebroeck et al. 1997, Tolias et al. 1998, Schaletzky et al. 2003, Kim et al. 2002, Clarke et al. 2010). Many of the phosphatidylinositol phosphatases that act at the plasma membrane belong to the myotubularin family. Enzymatically inactive myotubularin family members can heterodimerize with catalytically active mytotubularins to regulate their stability, activity and/or substrate specificity (Berger et al. 2006, Zou et al. 2012)."
BMGC_PW0608,BMG_PW2935,,,"At the Golgi membrane, phosphatidylinositol 4-phosphate (PI4P) is primarily generated from phosphorylation of phosphatidylinositol (PI). Other phosphoinositides are also generated by the action of various kinases and phosphatases such as: phosphatidylinositol 3-phosphate (PI3P), phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2), phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) (Godi et al. 1999, Minogue et al. 2001, Rohde et al. 2003, Sbrissa et al. 2007, Sbrissa et al. 2008, Domin et al. 2000, Arcaro et al. 2000)."
BMGC_PW0609,BMG_PW2936,,,"At the early endosome membrane, phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) is generated in two steps from phosphatidylinositol 3,4-bisphosphate PI(3,4)P2 by the action of various kinases and phosphatases (Sbrissa et al. 2007, Sbrissa et al. 2008, Cao et al. 2007, Cao et al. 2008, Arcaro et al. 2000, Kim et al. 2002)."
BMGC_PW0610,BMG_PW2937,,,"At the late endosome membrane, the primary event is the dephosphorylation of the phosphoinositide phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2) to phosphatidylinositol 3-phosphate (PI3P) and phosphatidylinositol 5-phosphate (PI5P) (Sbrissa et al. 2007, Sbrissa et al. 2008, Cao et al. 2007, Cao et al. 2008, Arcaro et al. 2000, Kim et al. 2002)."
BMGC_PW0611,BMG_PW2940,,,"The first known downstream component of TLR4 and TLR2 signaling is the adaptor MyD88. Another adapter MyD88-adaptor-like (Mal; also known as TIR-domain-containing adaptor protein or TIRAP) has also been described for TLR4 and TLR2 signaling. MyD88 comprises an N-terminal Death Domain (DD) and a C-terminal TIR, whereas Mal lacks the DD. The TIR homotypic interactions bring adapters into contact with the activated TLRs, whereas the DD modules recruit serine/threonine kinases such as interleukin-1-receptor-associated kinase (IRAK). Recruitment of these protein kinases is accompanied by phosphorylation, which in turn results in the interaction of IRAKs with TNF-receptor-associated factor 6 (TRAF6). The oligomerization of TRAF6 activates TAK1, a member of the MAP3-kinase family, and this leads to the activation of the IkB kinases. These kinases, in turn, phosphorylate IkB, leading to its proteolytic degradation and the translocation of NF-kB to the nucleus. Concomitantly, members of the activator protein-1 (AP-1) transcription factor family, Jun and Fos, are activated, and both AP-1 transcription factors and NF-kB are required for cytokine production, which in turn produces downstream inflammatory effects."
BMGC_PW0612,BMG_PW2941,,,"The MyD88-independent signaling pathway is shared by TLR3 and TLR4 cascades. TIR-domain-containing adapter-inducing interferon-beta (TRIF or TICAM1) is a key adapter molecule in transducing signals from TLR3 and TLR4 in a MyD88-independent manner (Yamamoto M et al. 2003a). TRIF is recruited to the ligand-stimulated TLR3 or 4 complex via its TIR domain. TLR3 directly binds TRIF (Oshiumi H et al 2003). In contrast, the TLR4-mediated signaling pathway requires two adapter molecules, TRAM (TRIF-related adapter molecule or TICAM2) and TRIF. TRAM(TICAM2) is thought to bridge the activated TLR4 complex and TRIF (Yamamoto M et al. 2003b, Tanimura N et al. 2008, Kagan LC et al. 2008). TRIF recruitment to the TLR complex stimulates distinct pathways leading to the production of type I interferons (IFNs) and pro-inflammatory cytokines and to the induction of programmed cell death."
BMGC_PW0613,BMG_PW2942,,,"The protonmotive force across the inner mitochondrial membrane built up by respiratory electron transport does not go entirely into ATP production. Transport proteins of the SLC25 type utilize the gradient to symport small molecules with protons into the matrix, simultaneously generating heat (""thermogenesis""). UCP1 and AAC1 have been shown to import protons exclusively and are responsible for most heat generated in brown fat and other tissue, respectively (reviewed in Bertholet & Kirichok, 2022). Uncoupling proteins (UCPs) are members of the mitochondrial transport carrier family. The crystal structure of one member of the family, the adenine nucleotide translocase, is known, and UCPs can be successfully folded into this structure to indicate their probable 3D arrangement (Pebay-Peyroula et al. 2003, Kunji 2004, Esteves & Brand 2005). The most studied member of the family, UCP1, catalyzes adaptive thermogenesis (i.e., heat generation) in mammalian brown adipose tissue. It does so by promoting a leak of protons through the mitochondrial inner membrane, which uncouples ATP production from substrate oxidation, leading to fast oxygen consumption and ultimately to heat production. The thermogenic activity of UCP1 in brown adipose tissue plays an important role when the organism needs extra heat, e.g., during cold weather conditions (for small rodents), the cold stress of birth, or arousal from hibernation. UCP1 homologs have been found in lower vertebrates such as fish, where their role is unclear (Cannon & Nedergaard 2004, Jastroch et al. 2005). The proton conductance of UCP1 in brown adipose tissue is tightly controlled. It is strongly inhibited by physiological concentrations of purine nucleotides. This inhibition is overcome by fatty acids released from intracellular triacylglycerol stores following adrenergic activation in response to cold or overfeeding. Other activators include superoxide, retinoic acid, the retinoid 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetra-methyl-2-naphtalenyl)-1-propenyl]benzoic acid (TTNPB) and reactive alkenals, such as hydroxynonenal. There is strong evidence that the regulated uncoupling caused by these proteins attenuates mitochondrial reactive oxygen species production, protects against cellular damage, and (in beta-cells) diminishes insulin secretion. There are also untested suggestions that their transport of fatty acids may be physiologically important (Brand & Esteves 2005, Esteves & Brand 2005, Krauss et al. 2005). Several models have been proposed for the molecular mechanism by which fatty acids lead to increased proton conductance by UCP1 in brown adipose tissue mitochondria and presumably by the other UCPs. We have depicted the most likely model, the ""fatty acid cycling"" model, in this pathway . Studies of mouse models and cultured human cells have suggested that oleoyl-phenylalanine, synthesized by extracellular PM20D1, may play a role in uncoupling independent of the action of UCPs (Long et al., 2016). Its synthesis and hydrolysis are annotated here."
BMGC_PW0614,BMG_PW2943,,,"mTORC1 integrates four major signals – growth factors, energy status, oxygen and amino acids – to regulate many processes that are involved in the promotion of cell growth. Growth factors stimulate mTORC1 through the activation of the canonical insulin and Ras signaling pathways. The energy status of the cell is signaled to mTORC1 through AMP-activated protein kinase (AMPK), a key sensor of intracellular energy status (Hardie 2007). Energy depletion (low ATP:ADP ratio) activates AMPK which phosphorylates TSC2, increasing its GAP activity towards Rheb which reduces mTORC1 activation (Inoki et al. 2003). AMPK can reduce mTORC1 activity by directly phosphorylating Raptor (Gwinn et al. 2008). Amino acids positively regulate mTORC1 (reviewed by Guertin & Sabatini 2007). In the presence of amino acids, Rag proteins bind Raptor to promote the relocalization of mTORC1 from the cytoplasm to lysosomal membranes (Puertollano 2014) where it is activated by Rheb (Saucedo et al. 2003, Stocker et al. 2003). Translocation of mTOR to the lysosome requires active Rag GTPases and a complex known as Ragulator, a pentameric protein complex that anchors the Rag GTPases to lysosomes (Sancak et al. 2008, 2010, Bar-Peled et al. 2012). Rag proteins function as heterodimers, consisting of GTP-bound RagA or RagB complexed with GDP-bound RagC or RagD. Amino acids may trigger the GTP loading of RagA/B, thereby promoting binding to raptor and assembly of an activated mTORC1 complex, though a recent study suggested that the activation of mTORC1 is not dependent on Rag GTP charging (Oshiro et al. 2014). The activity of Rheb is regulated by a complex consisting of tuberous sclerosis complex 1 (TSC1), TSC2, and TBC1 domain family member 7 (TBC1D7) (Huang et al. 2008, Dibble et al. 2012). This complex localizes to lysosomes and functions as a GTPase-activating protein (GAP) that inhibits the activity of Rheb (Menon et al. 2014, Demetriades et al. 2014). In the presence of growth factors or insulin, TSC releases its inhibitory activity on Rheb, thus allowing the activation of mTORC1."
BMGC_PW0615,BMG_PW2944,,,"Sulfatase activity requires a unique posttranslational modification (PTM) of a catalytic cysteine residue into a formylglycine. This modification is impaired in patients with multiple sulfatase deficiency (MSD) due to defects in the SUMF1 (sulfatase-modifying factor 1) gene responsible for this PTM. SUMF2 can inhibit the activity of SUMF1 thereby providing a mechanism for the regulation of sulfatase activation (Ghosh 2007, Diez-Roux & Ballabio 2005)."
BMGC_PW0616,BMG_PW2945,,,"Neurotrophins (NGF, BDNF, NTF3 and NTF4) play pivotal roles in survival, differentiation, and plasticity of neurons in the peripheral and central nervous system. They are produced, and secreted in minute amounts, by a variety of tissues. They signal through two types of receptors: NTRK (TRK) tyrosine kinase receptors (TRKA, TRKB, TRKC), which differ in their preferred neurotrophin ligand, and p75NTR death receptor, which interacts with all neurotrophins. Besides the nervous system, TRK receptors and p75NTR are expressed in a variety of other tissues. For review, please refer to Bibel and Barde 2000, Poo 2001, Lu et al. 2005, Skaper 2012, Park and Poo 2013. NTRK receptors, NTRK1 (TRKA), NTRK2 (TRKB) and NTRK3 (TRKC) are receptor tyrosine kinases activated by ligand binding to their extracellular domain. Ligand binding induces receptor dimerization, followed by trans-autophosphorylation of dimerized receptors on conserved tyrosine residues in the cytoplasmic region. Phosphorylated tyrosines in the intracellular domain of the receptor serve as docking sites for adapter proteins, triggering downstream signaling cascades. NTRK1 (TRKA) is the receptor for the nerve growth factor (NGF). NGF is primarily secreted by tissues that are innervated by sensory and sympathetic neurons. NTRK1 signaling promotes growth and survival of neurons during embryonic development and maintenance of neuronal cell integrity in adulthood (reviewed by Marlin and Li 2015). Brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NTF4, also known as NT-4) are two high affinity ligands for NTRK2 (TRKB). Neurotrophin-3 (NTF3, also known as NT-3) binds to NTRK2 with low affinity and may not be a physiologically relevant ligand. Nerve growth factor (NGF), a high affinity ligand for NTRK1, does not interact with NTRK2. NTRK2 signaling is implicated in neuronal development in both the peripheral (PNS) and central nervous system (CNS) and may play a role in long-term potentiation (LTP) and learning (reviewed by Minichiello 2009). NTRK2 may modify neuronal excitability and synaptic transmission by directly phosphorylating voltage gated channels (Rogalski et al. 2000). NTF3 (NT-3) is the ligand for NTRK3 (TRKC). Signaling downstream of activated NTRK3, regulates cell survival, proliferation and motility. In the absence of its ligand, NTRK3 functions as a dependence receptor and triggers BAX and CASP9-dependent cell death (Tauszig-Delamasure et al. 2007, Ichim et al. 2013)."
BMGC_PW0617,BMG_PW2946,,,"Complement activation is due to a cascade of proteolytic steps, performed by serine protease domains in some of the components. Three different pathways of activation are distinguished triggered by target-bound antibody (the classical pathway); microbial polysaccharide structures (the lectin pathway); or recognition of other ""foreign"" surface structures (the alternative pathway) by C3b. All three merge in the pivotal activation of C3 and, subsequently, of C5 by highly specific enzymatic complexes, the so-called C3/C5 convertases. A complement system with three C3 activation pathways and a common lytic pathway is found only in jawed vertebrates."
BMGC_PW0618,BMG_PW2947,,,"After cleavage of C5, C5b undergoes conformational changes and exposes a binding site for C6. C5b6 binds C7 resulting in the exposure of membrane binding sites and incorporation into target membranes. The membrane-bound C5b-7 complex can then bind C8. C5b-8 acts as a polymerizing agent for C9. The first C9 bound to C5b-8 undergoes major structural changes enabling formation of an elongated molecule and allows binding of additional C9 molecules and insertion of C9 cylinders into the target membrane. The number of C9 molecules varies from 1-12 in the membrane, although polymers containing up to fifteen C9 molecules are also possible."
BMGC_PW0619,BMG_PW2948,,,"Two pathways lead to a complex capable of activating C4 and C2. The classical pathway is triggered by activation of the C1-complex, which consists of hexameric molecule C1q and a tetramer comprising two C1r and two C1s serine proteinases. This occurs when C1q binds to IgM or IgG complexed with antigens, a single IgM can initiate the pathway while multiple IgGs are needed, or when C1q binds directly to the surface of the pathogen. Binding leads to conformational changes in C1q, activating the serine protease activity of C1r, which then cleaves C1s, another serine protease. The C1r:C1s component is now capable of splitting C4 and C2 to produce the classical C3-convertase C4b2a. C1r and C1s are additionally controlled by C1-inhibitor.(Kerr MA 1980) The lectin pathway is similar in operation but has different components. Mannose-binding lectin (MBL) or ficolins (L-ficolin, M-ficolin and H-ficolin) initiate the lectin pathway cascade by binding to specific carbohydrate patterns on pathogenic cell surfaces. MBL and ficolins circulate in plasma in complexes with homodimers of MBL-associated serine proteases (MASP) (Fujita et al. 2004; Hajela et al. 2002). Upon binding of human lectin (MBL or ficolins) to the target surface the complex of lectin:MASP undergoes conformational changes, which results in the activation of MASPs by cleavage (Matsushita M et al. 2000; Fujita et al. 2004). Activated MASPs become capable of C4 and C2 cleavage, giving rise to the same C3 convertase C4b:C2a as the classical pathway."
BMGC_PW0620,BMG_PW2949,,,The activation of phosphlipase C-gamma (PLC-gamma) and subsequent mobilization of calcium from intracellular stores are essential for neurotrophin secretion. PLC-gamma is activated through the phosphorylation by TrkA receptor kinase and this form hydrolyses PIP2 to generate inositol tris-phosphate (IP3) and diacylglycerol (DAG). IP3 promotes the release of Ca2+ from internal stores and this results in activation of enzymes such as protein kinase C and Ca2+ calmodulin-regulated protein kinases.
BMGC_PW0621,BMG_PW2950,,,"Signalling through Shc adaptor proteins appears to be identical for both NGF and EGF. It leads to a fast, but transient, MAPK/ERK activation, which is insufficient to explain the prolonged activation of MAPK found in NGF-treated cells."
BMGC_PW0622,BMG_PW2952,,,"During the formation of the HIV elongation complex in the absence of HIV Tat, eongation factors are recruited to form the HIV-1 elongation complex (Hill and Sundquist 2013) and P-TEFb complex hyperphosphorylates RNA Pol II CTD (Hermann and Rice, 2005, Zhou et al., 2000)."
BMGC_PW0623,BMG_PW2953,,,"This HIV-1 event was inferred from the corresponding human RNA Poll II transcription event. The details relevant to HIV-1 are described below. Formation of the early elongation complex involves hypophosphorylation of RNA Pol II CTD by FCP1P protein, association of the DSIF complex with RNA Pol II, and formation of DSIF:NELF:HIV-1 early elongation complex as described below (Mandal et al 2002; Kim et al 2003; Yamaguchi et al 2002)."
BMGC_PW0624,BMG_PW2954,,,"To facilitate co-transcriptional capping, and thereby restrict the cap structure to RNAs made by RNA polymerase II, the capping enzymes bind directly to the RNA polymerase II. The C-terminal domain of the largest Pol II subunit contains several phosphorylation sites on its heptapeptide repeats. The capping enzyme guanylyltransferase and the methyltransferase bind specifically to CTD phosphorylated at Serine 5 within the CTD. Kinase subunit of TFIIH, Cdk7, catalyzes this phosphorylation event that occurs near the promoter. In addition, it has been shown that binding of capping enzyme to the Serine-5 phosphorylated CTD stimulates guanylyltransferase activity in vitro."
BMGC_PW0625,BMG_PW2955,,,"Formation of the open complex exposes the template strand to the catalytic center of the RNA polymerase II enzyme. This facilitates formation of the first phosphodiester bond, which marks transcription initiation. As a result of this, the TFIIB basal transcription factor dissociates from the initiation complex. The open transcription initiation complex is unstable and can revert to the closed state. Initiation at this stage requires continued (d)ATP-hydrolysis by TFIIH. Dinucleotide transcripts are not stably associated with the transcription complex. Upon dissociation they form abortive products. The transcription complex is also sensitive to inhibition by small oligo-nucleotides. Dinucleotides complementary to position -1 and +1 in the template can also direct first phosphodiester bond formation. This reaction is independent on the basal transcription factors TFIIE and TFIIH and does not involve open complex formation. This reaction is sensitive to inhibition by single-stranded oligonucleotides."
BMGC_PW0626,BMG_PW2956,,,RNA Polymerase II promoter escape occurs after the first phosphodiester bond has been created.
BMGC_PW0627,BMG_PW2957,,,"In the absence of the HIV-1 protein Tat, transcription of the proviral DNA is inefficient and results in the production of truncated transcripts (Kao et al., 1987). While initiation of transcription from the HIV-1 LTR and formation of the early elongation complex occurs normally, transcription elongation is incomplete with non-processive polymerases disengaging from the proviral DNA template prematurely (reviewed in Karn 1999). The mechanism of Tat-mediated elongation is described below."
BMGC_PW0628,BMG_PW2958,,,"Expression of the integrated HIV-1 provirus is dependent on the host cell Pol II transcription machinery, but is regulated in critical ways by HIV-1 Tat and Rev proteins. The long terminal repeats (LTR) located at either end of the proviral DNA contain regulatory sequences that recruit cellular transcription factors. The U3 region of the 5' LTR contains numerous cis-acting elements that regulate Pol II-mediated transcription initiation. The full-length transcript, which encodes nine genes, functions as an mRNA and is packaged as genomic RNA. Smaller (subgenomic) viral mRNAs are generated by alternative splicing. The activities of Tat and Rev create two phases of gene expression (see Karn 1999; Cullen 1991). The Tat protein is an RNA specific trans-activator of LTR-mediated transcription. Association of Tat with TAR, a RNA stem-loop within the RNA leader sequence, is required for efficient elongation of the HIV-1 transcript. In the early phase of viral transcription, a multiply-spliced set of mRNAs is generated, producing the transcripts of the regulatory proteins, Tat, Rev, and Nef. In the late phase, Rev regulates nuclear export of HIV-1 mRNAs, repressing expression of the early regulatory mRNAs and promoting expression of viral structural proteins. Nuclear export of the unspliced and partially spliced late HIV-1 transcripts that encode the structural proteins requires the association of Rev with a cis-acting RNA sequence in the transcripts (Rev Response Element, RRE)."
BMGC_PW0629,BMG_PW2959,,,"This HIV-1 event was inferred from the corresponding human RNA Poll II transcription event in Reactome. The details relevant to HIV-1 are described below. For a more detailed description of the general mechanism, see the link to the corresponding RNA Pol II transcription event below. The formation of the HIV-1 elongation complex involves Tat mediated recruitment of P-TEFb(Cyclin T1:Cdk9) to the TAR sequence (Wei et al, 1998) and P-TEFb(Cyclin T1:Cdk9) mediated phosphorylation of the RNA Pol II CTD as well as the negative transcriptional elongation factors DSIF and NELF (Herrmann, 1995; Ivanov et al. 2000; Fujinaga et al. 2004; Zhou et al., 2004)."
BMGC_PW0630,BMG_PW2960,,,"After Pol II pauses by back tracking 2 -4 nuleotides on the HIV-1 template, elongation of the HIV-1 transcript resumes."
BMGC_PW0631,BMG_PW2961,,,"This event was inferred from the corresponding Reactome human Poll II transcription elongation event. The details specific to HIV-1 transcription elongation are described below. In the absence of the HIV-1 Tat protein, the RNA Pol II complexes associated with the HIV-1 template are non-processive. RNA Pol II is arrested after promoter clearance by the negative transcriptional elongation factors DSIF and NELF as occurs during early elongation of endogenous templates (Wada et al, 1998; Yamaguchi et al. 1999). This arrest cannot be overcome by P-TEFb mediated phosphorylation in the absence of Tat however, and elongation aborts resulting in the accumulation of short transcripts (Kao et al., 1987)."
BMGC_PW0632,BMG_PW2962,,,RNA Pol II arrest is believed to be a result of irreversible backsliding of the enzyme by ~7-14 nucleotides. TFIIS reactivates arrested RNA Pol II by promoting the excision of nascent transcript ~7-14 nucleotides upstream of the 3' end.
BMGC_PW0633,BMG_PW2963,,,"The Tat protein is a viral transactivator protein that regulates HIV-1 gene expression by controlling RNA Pol II-mediated elongation (reviewed in Karn 1999; Taube et al. 1999; Liou et al. 2004; Barboric and Peterlin 2005). Tat appears to be required in order to overcome the arrest of RNA Pol II by the negative transcriptional elongation factors DSIF and NELF (Wada et al. 1998; Yamaguchi et al. 1999; Yamaguchi et al 2002; Fujinaga et al. 2004). While Pol II can associate with the proviral LTR and initiate transcription in the absence of Tat, these polymerase complexes are non-processive and dissociate from the template prematurely producing very short transcripts (Kao et al. 1987). Tat associates with the RNA element, TAR, which forms a stem loop structure in the leader RNA sequence (Dingwall et al. 1989). Tat also associates with the cellular kinase complex P-TEFb(Cyclin T1:Cdk9) and recruits it to the TAR stem loop structure (Herrmann, 1995) (Wei et al. 1998). This association between Tat, TAR and P-TEFb(Cyclin T1:Cdk9) is believed to bring the catalytic subunit of this kinase complex (Cdk9) in close proximity to Pol II where it hyperphosphorylates the CTD of RNA Pol II (Zhou et al. 2000). The RD subunits of NELF and the SPT5 subunit of DSIF, which associate through RD with the bottom stem of TAR, are also phosphorylated by P-TEFb(Cyclin T1:Cdk9) (Yamaguchi et al. 2002; Fujinaga et al. 2004; Ivanov et al. 2000). Phosphorylation of RD results in its dissociation from TAR. Thus, Tat appears to facilitate transcriptional elongation of the HIV-1 transcript by hyperphosphorylating the RNA Poll II CTD and by removing the negative transcription elongation factors from TAR. In addition, there is evidence that the association of Tat with P-TEFb(Cyclin T1:Cdk9) alters the substrate specificity of P-TEFb enhancing phosphorylation of ser5 residues in the CTD of RNA Pol II (Zhou et al. 2000)."
BMGC_PW0634,BMG_PW2964,,,RNA Pol II arrest is believed to be a result of irreversible backsliding of the enzyme by ~7-14 nucleotides. TFIIS reactivates arrested RNA Pol II by promoting the excision of nascent transcript ~7-14 nucleotides upstream of the 3' end.
BMGC_PW0635,BMG_PW2965,,,"After Pol II pauses by back tracking 2 -4 nuleotides on the HIV-1 template, elongation of the HIV-1 transcript resumes."
BMGC_PW0636,BMG_PW2966,,,"The presence of Nef accelerates endocytosis and lysosomal degradation of the transmembrane glycoprotein CD4. CD4 has its own internalization motif, though this motif is normally concealed by CD4 interaction with Lck, a tyrosine kinase. Nef is known to disrupt this interaction and then facilitate a cascade of protein interactions that ultimately result in the degradation of internalized CD4 protein. The final set of protein interactions that direct Nef to the beta-subunit of the COPI coatomers are at this time unclear. A benefit for the virus from CD4 down-modulation is abolition of interaction between the receptor and the Env protein of the budding virus, which likely increases HIV release from infected cell as well as infectivity of viral particles."
BMGC_PW0637,BMG_PW2967,,,"The ""fatty acid cycling"" hypothesis proposes that protonated fatty acids flip-flop in the membrane and deliver a proton to the matrix side. UCP1 catalyses the return of the fatty acid anion to the cytosolic side of the membrane, resulting in net proton transport catalysed by the protein."
BMGC_PW0638,BMG_PW2968,,,"Mammalian TLR3, TLR7, TLR8, TLR9 are endosomal receptors that sense nucleic acids that have been released from endocytosed/phagocytosed bacteria, viruses or parasites. These TLRs have a ligand-recognition domain that faces the lumen of the endosome (which is topologically equivalent to the outside of the cell), a transmembrane domain, and a signaling domain that faces the cytosol. Under normal conditions, self nucleic acids are not recognized by TLRs due to multiple levels of regulation including receptor compartmentalization, trafficking and proteolytic processing (Barton GM et al 2006, Ewald SE et al 2008). At steady state TLR3, TLR7, TLR8, TLR9 reside primarily in the endoplasmic reticulum (ER), however, their activation by specific ligands only occurs within acidified endolysosomal compartments (Hacker H et al 1998, Funami K et al 2004, Gibbard RJ et al 2006). Several chaperon proteins associate with TLRs in the ER to provide efficient translocation to endolysosome. Upon reaching endolysosomal compartments the ectodomains of TLR7 and TLR9 are proteolytically cleaved by cysteine endoproteases. Both full-length and cleaved C-terminus of TLR9 bind CpG-oligodeoxynucleotides, however it has been proposed that only the processed receptor is functional. Although similar cleavage of TLR3 has been reported by Ewald et al 2011, other studies demonstrated that the N-terminal region of TLR3 ectodomain was implicated in ligand binding, thus TLR3 may function as a full-length receptor (Liu L et al 2008, Tokisue T et al 2008). There are no data on TLR8 processing, although the cell biology of TLR8 is probably similar to TLR9 and TLR7 (Gibbard RJ et al 2006, Wei T et al 2009)."
BMGC_PW0639,BMG_PW2969,,,"For centuries influenza epidemics have plagued man; with influenza probably being the disease described by Hippocrates in 412 BC. Today it remains a major cause of morbidity and mortality worldwide with large segments of the human population affected every year. Many animal species can be infected by influenza viruses, often with catastrophic consequences. An influenza pandemic is a continuing global level threat. The 1918 influenza pandemic is a modern example of how devastating such an event could be with an estimated 50 million deaths worldwide. Influenza viruses belong to the family of Orthomyxoviridae; viruses with segmented RNA genomes that are negative sense and single-stranded (Baltimore 1971). Influenza virus strains are named according to their type (A, B, or C), the species from which the virus was isolated (omitted if human), location of isolate, the number of the isolate, the year of isolation, and in the case of influenza A viruses, the hemagglutinin (H) and neuraminidase (N) subtype. For example, the virus of H5N1 subtype isolated from chickens in Hong Kong in 1997 is: influenza A/chicken/Hong Kong/220/97(H5N1) virus. Currently 16 different hemagglutinin (H1 to H16) subtypes and 9 different neuraminidase (N1 to N9) subtypes are known for influenza A viruses. Most human disease is due to influenza viruses of the A type. The events of influenza infection have been annotated in Reactome primarily use protein and genome references to the Influenza A virus A/Puerto Rico/8/1934 H1N1 strain. The influenza virus particle initially associates with a human host cell by binding to sialic acid receptors on the host cell surface. Sialic acids are found on many vertebrate cells and numerous viruses make use of this ubiquitous receptor. The bound virus is endocytosed by one of four distinct mechanisms. Once endocytosed the low endosomal pH sets in motion a number of steps that lead to viral membrane fusion mediated by the viral hemagglutinin (HA) protein, and the eventual release of the uncoated viral ribonucleoprotein complex into the cytosol of the host cell. The ribonucleoprotein complex is transported through the nuclear pore into the nucleus. Once in the nucleus, the incoming negative-sense viral RNA (vRNA) is transcribed into messenger RNA (mRNA) by a primer-dependent mechanism. Replication occurs via a two step process. A full-length complementary RNA (cRNA), a positive-sense copy of the vRNA, is first made and this in turn is used as a template to produce more vRNA. The viral proteins are expressed and processed and eventually assemble with vRNAs at what will become the budding sites on the host cell membrane. The viral protein and ribonucleoprotein complexes are assembled into complete viral particles and bud from the host cell, enveloped in the host cell's membrane. Infection of a human host cell with influenza virus triggers an array of defensive host processes. This coevolution has driven the development of host processes that interfere with viral replication, notably the production of type I interferon. At the some time the virus counters these responses with the viral NS1 protein playing a central role in the viral response to the host cells defense."
BMGC_PW0640,BMG_PW2972,,,"An unusual characteristic of the influenza virus life cycle is its dependence on the nucleus. Trafficking of the viral genome into and out of the nucleus is a tightly regulated process with all viral RNA synthesis occurring in the nucleus. The eight influenza virus genome segments never exist as naked RNA but are associated with four viral proteins to form viral ribonucleoprotein complexes (vRNPs). The major viral protein in the RNP complex is the nucleocapsid protein (NP), which coats the RNA. The remaining proteins PB1, PB2 and PA bind to the partially complementary ends of the viral RNA, creating the distinctive panhandle structure. These RNPs (10-20nm wide) are too large to passively diffuse into the nucleus and therefore, once released from an incoming particle must rely on the active import mechanism of the host cell nuclear pore complex. All proteins in the RNP complex can independently localize to the nucleus due to the presence of nuclear localization signals (NLSs) which mediate their interaction with the nuclear import machinery, including the RanGTPase (Fodor, 2004; Deng et al., 2006). However the signals on NP have been shown to be both sufficient and necessary for the import of viral RNA."
BMGC_PW0641,BMG_PW2973,,,"In the host cell nucleus, the viral negative-strand RNA (vRNA) serves as a template for the synthesis both of capped, polyadenylated viral messenger RNA and of full-length positive-strand RNA or complementary RNA (cRNA). The cRNA is associated with the same viral proteins as the vRNA. It serves as a template for the synthesis of new vRNA molecules, which in turn serve as a template for mRNA particularly early in infection, and cRNA. Viral RNA polymerase subunits (PB1, PB2, and PA) and nucleoprotein (NP) enter the host cell nucleus and catalyze all three of these reactions. During initial infection, these proteins enter the nucleus as part of the viral RNP complex. After the first round of viral mRNA synthesis (primary transcription) and translation, newly synthesized viral polymerase proteins and NP localize to the nucleus to catalyze further mRNA transcription and vRNA/cRNA replication. Late in the infection process, the synthesis of vRNA and nuclear export of newly synthesized vRNP (vRNA complexed with NP and viral polymerase) is increased relative to transcription (Krug, 1981; Braam, 1983; Kawakami, 1983; Huang, 1990; Cros, 2003; Fodor, 2004; Deng, 2005; Amorim, 2006; reviewed in Neumann, 2004; Engelhardt, 2006; Buolo, 2006)."
BMGC_PW0642,BMG_PW2974,,,"Influenza genomic RNA (vRNA), synthesized in the nucleus of the infected host cell, is packaged into ribonucleoprotein (RNP) complexes containing viral polymerase proteins and NP (nucleocapsid). NP trimers bind the sugar phosphate backbone of the vRNA. As influenza viral RNP complexes are too large for passive diffusion out of the nucleus, utilization of the cellular nuclear export machinery is achieved by viral adaptor proteins. Matrix protein (M1) is critical for export of the complex from the nucleus, mediating the interaction of the RNP complex with the viral NEP/NS2 protein, which in turn interacts with host cell CRM1/exportin-1 nuclear export protein (Martin, 1991; O'Neill, 1998; Neumann et al., 2000; Elton, 2001; Cros, 2003; Ye, 2006; reviewed in Boulo, 2006)."
BMGC_PW0643,BMG_PW2976,,,"Viral NS1 protein is a nuclear, dimeric protein that is highly expressed in infected cells and has dsRNA-binding activity. The RNA-binding domain lies within the N-terminal portion of the protein. The NS1 RNA-binding domain forms a symmetric homodimer with a six-helical fold. Mutational analysis has demonstrated that dimer formation is crucial for RNA-binding. The basic residues are believed to make contact with the phosphate backbone of the RNA which is consistent with an observed lack of sequence specificity. Neither NS1 nor its bound RNA undergo any significant structural changes upon binding. The NS1 dimer spans the minor groove of canonical A-form dsRNA. The non-RNA binding portion of NS1 has been termed the effector domain and includes binding sites for host cell poly (A)-binding protein II (PABII) and the 30kDa subunit of cleavage and polyadenylation specificity factor (CPSF)."
BMGC_PW0644,BMG_PW2985,,,"Like the mRNAs of the host cell, influenza virus mRNAs are capped and polyadenylated (reviewed in Neumann, 2004). The methylated caps, however, are scavenged from host cell mRNAs and serve as primers for viral RNA synthesis, a process termed 'cap-snatching' (Krug, 1981; Hagen, 1994). The PB2 polymerase protein binds the cap, activating endonucleolytic cleavage of the host mRNA by PB1. The 3' poly-A tracts on viral messages are generated by polymerase stuttering on poly-U tracts near the 5' end of the template vRNA (Robertson, 1981; Zheng, 1999). The second process allows polyadenylation of viral mRNAs when the host cell polyadenylation process has been inhibited (Engelhardt, 2006; Amorim, 2006). Notably, early transcripts (including NP and NS1) accumulate in the cytoplasm before late transcripts (M1, HA, and NS2), and in varying abundances, suggesting additional control mechanisms regulating viral gene expression (Shapiro, 1987; Hatada, 1989; Amorim, 2006)."
BMGC_PW0645,BMG_PW2987,,,"The viral RNP complex is exported from the nucleus via the host cell CRM1 export pathway (Fukuda, 1997; Neumann, 2000; reviewed in Buolo, 2006). The vRNP complex does not interact directly with CRM1 to form an export complex. Rather, an additional viral protein, nuclear export protein (NEP/NS2), acts as an adaptor, binding the viral matrix M1 protein and CRM1, thus linking the viral RNP with CRM1 (Martin, 1991; O'Neill, 1998; Neumann, 2000; Akarsu, 2003). The CRM1/exportin-1 complex recruits additional host cell proteins, and traverses the nuclear pore into the cytosol."
BMGC_PW0646,BMG_PW2989,,,"NOD1 is ubiquitously expressed, while NOD2 expression is restricted to monocytes, macrophages, dendritic cells, and intestinal Paneth cells (Inohara et al. 2005). NOD1 and NOD2 activation induces transcription of immune response genes, predominantly mediated by the proinflammatory transcriptional factor NFkappaB but also by AP-1 and Elk-1 (Inohara et al. 2005). NFkappaB translocates to the nucleus following release from IkappaB proteins. NOD1 and NOD2 signaling involves an interaction between their caspase-recruitment domain (CARD) and the CARD of the kinase RIPK2 (RIP2/RICK). This leads to the activation of the NFkappaB pathway and MAPK pathways (Windheim et al. 2007). Activated NODs oligomerize via their NACHT domains, inducing physical proximity of RIP2 proteins that is believed to trigger their K63-linked polyubiquitination, facilitating recruitment of the TAK1 complex. RIP2 also recruits NEMO, bringing the TAK1 and IKK complexes into proximity, leading to NF-kappaB activation and activation of MAPK signaling. Recent studies have demonstrated that K63-linked regulatory ubiquitination of RIP2 is essential for the recruitment of TAK1 (Hasegawa et al. 2008, Hitosumatsu et al. 2008). As observed for toll-like receptor (TLR) signaling, ubiquitination can be removed by the deubiquitinating enzyme A20, thereby dampening NOD1/NOD2-induced NF-kappaB activation. NOD1 and NOD2 both induce K63-linked ubiquitination of RIP2, but NOD2-signaling appears to preferentially utilize the E3 ligase TRAF6, while TRAF2 and TRAF5 were shown to be important for NOD1-mediated signaling. In both cases, activation of NF-kappaB results in the upregulated transcription and production of inflammatory mediators."
BMGC_PW0647,BMG_PW2990,,,"Clostridial neurotoxins, when taken up by human neurons, block synaptic transmission by cleaving proteins required for the fusion of synaptic vesicles with the plasma membrane. They are remarkably efficient so that very small doses cause paralysis of an affected person (Lalli et al. 2003; Turton et al. 2002). All characterized clostridial neurotoxins are synthesized as products of chromosomal, plasmid or prophage-borne bacterial genes. The nascent toxin may be cleaved into light (LC) and heavy (HC) chain moieties that remain attached by noncovalent interactions and a disulfide bond (Turton et al. 2002). Strains of Clostridium botulinum produce seven serologically distinct toxins, BoNT/A, B, C, D, E, F, and G. An eighth toxin, BoNT/H has recently been identified (Barash & Arnon 2014) but its molecular properties have not yet been described. Human poisoning most commonly result from ingestion of toxin contaminated food. More rarely, it is due to wound infection or clostridial colonization of the gut of an infant whose own gut flora have not yet developed or of an older individual whose flora have been suppressed. While all seven characterized toxins can cleave human target proteins, three, BoNT/A, B, and E, are most commonly associated with human disease (Hatheway 1995; Sakaguchi 1982). BoNT/F is also able to cause human botulism. Once ingested, the botulinum toxin must be taken up from the gut lumen into the circulation, a process mediated by four accessory proteins. These proteins form a complex that mediates transcytosis of the toxin molecule across the gut epithelium, allowing its entry into the circulation. The accessory proteins produced by different C. botulinum strains differ in their affinities for polarized epithelia of different species (e.g., human versus canine), and may thus be a key factor in human susceptibility to the toxins of strains A, B, and E and resistance to the others (Simpson 2004). Clostridium tetani produces TeNT toxin. Human poisoning is the result of toxin secretion by bacteria growing in an infected wound and the toxin is released directly into the circulation. Circulating clostridial toxins are taken up by neurons at neuromuscular junctions. They bind to specific gangliosides (BoNT/C, TeNT) or to both gangliosides and synaptic vesicle proteins (BoNT/A, B, D G) exposed on the neuronal plasma membrane during vesicle exocytosis (Montal 2010). All seven characterized forms of BoNT are thought to be taken up into synaptic vesicles as these re-form at the neuromuscular junction. These vesicles remain close to the site of uptake and are rapidly re-loaded with neurotransmitter and acidified (Sudhoff 2004). TeNT, in contrast, is taken up into clathrin coated vesicles that reach the neuron cell body by retrograde transport and then possibly other neurons before undergoing acidification. Vesicle acidification causes a conformational change in the toxin, allowing its HC part to function as a channel through which its LC part is extruded into the neuronal cytosol. The HC - LC disulfide bond is cleaved and the cytosolic LC functions as a zinc metalloprotease to cleave specific bonds in proteins on the cytosolic faces of synaptic vesicles and plasma membranes that normally mediate exocytosis (Lalli et al. 2003; Montal 2010)."
BMGC_PW0648,BMG_PW2994,,,"RIG-I-like helicases (RLHs) the retinoic acid inducible gene-I (RIG-I, DDX58) and melanoma differentiation associated gene 5 (MDA5, IFIH1) are RNA helicases that recognize viral double-stranded RNA (dsRNA) present within the cytoplasm (Yoneyama M & Fujita T 2007, 2008). Upon viral infection dsRNA is generated by positive-strand RNA virus families such as Flaviviridae and Coronaviridae, negative-strand RNA virus families including Orthomyxoviridae and Paramyxoviridae, and DNA virus families such as Herpesviridae and Adenoviridae (Weber F et al. 2006; Son KN et al. 2015). Functionally RIG-I (DDX58) and MDA5 (IFIH1) positively regulate the IFN genes in a similar fashion, however they differ in their response to different viral species. DDX58 (RIG-I) is essential for detecting influenza virus, Sendai virus, VSV and Japanese encephalitis virus (JEV), whereas IFIH1 (MDA5) is essential in sensing encephalomyocarditis virus (EMCV), Mengo virus and Theiler's virus, all of which belong to the picornavirus family. RIG-I and MDA5 signalling results in the activation of IKK epsilon and (TKK binding kinase 1) TBK1, two serine/threonine kinases that phosphorylate interferon regulatory factor 3 and 7 (IRF3 and IRF7). Upon phosphorylation, IRF3 and IRF7 translocate to the nucleus and subsequently induce interferon alpha (IFNA) and interferon beta (IFNB) gene transcription (Yoneyama M et al. 2004; Yoneyama M & Fujita T 2007, 2008)."
BMGC_PW0649,BMG_PW2996,,,"After NGF binding, activated Trk receptors provide multiple docking sites for adaptor proteins and enzymes. Two docking proteins, the Ankyrin-Rich Membrane Spanning protein (ARMS/Kidins220) and Fibroblast growth factor receptor substrate 2 (Frs2), target signaling molecules in response to NGF stimulation and link receptor activation with the MAP kinase (also called the Extracellular signal-Regulated Kinase cascade, ERK) cascade, an essential process for growth factor-induced cell proliferation and differentiation. A feature of NGF signaling is the sustained activation of the MAPK cascade. This is achieved by the small G protein, Rap1 which binds to and activates B-Raf, an activator of the MAPK cascade. Rap1 is a member of the Ras family of G proteins and like all G proteins, Rap1 is in an inactive state when bound to GDP and is active when bound to GTP. A specific GEF (guanine nucleotide exchange factor) called C3G can activate Rap1 by exchanging GDP for GTP."
BMGC_PW0650,BMG_PW2997,,,"A regulated balance between cell survival and apoptosis is essential for normal development and homeostasis of multicellular organisms (see Matsuzawa, 2001). Defects in control of this balance may contribute to autoimmune disease, neurodegeneration and cancer. Protein ubiquitination and degradation is one of the major mechanisms that regulate apoptotic cell death (reviewed in Yang and Yu 2003)."
BMGC_PW0651,BMG_PW2998,,,"Cyclin A:Cdc2 complexes are detected in the nucleus earlier that cyclin B1:Cdc2 complexes and may play a role in the initial events in prophase. Inactivation of Cdc25B by proteasome-mediated degradation is dependent upon cyclin A:Cdc2-mediated phosphorylation (Cans et al, 1999)"
BMGC_PW0652,BMG_PW2999,,,"Stimulatory G proteins activate adenylate cyclase, which drives the conversion of cAMP from ATP and in turn activates cAMP-dependent protein kinase and subsequent kinase pathways."
BMGC_PW0653,BMG_PW3000,,,"Guanine nucleotide-binding protein G(i) alpha (Gi-alpha) inhibits adenylate cyclase, thus inhibiting the production of cAMP from ATP and ultimately decreasing the activity of cAMP-dependent protein kinase."
BMGC_PW0654,BMG_PW3001,,,"Glucokinase (GCK1) is negatively regulated by glucokinase regulatory protein (GKRP), which reversibly binds the enzyme to form an inactive complex. Binding is stimulated by fructose 6-phosphate and sorbitol 6-phosphate (hence high concentrations of these molecules tend to reduce GCK1 activity) and inhibited by fructose 1-phosphate (hence a high concentration of this molecule tends to increase GCK1 activity). Once formed, the complex is translocated to the nucleus. In the presence of high glucose concentrations, the nuclear GCK1:GKRP complex dissociates, freeing GCK1 to return to the cytosol. The free GKRP is thought also to return to the cytosol under these conditions, but this return has not been confirmed experimentally. Possible physiological roles for this sequestration process are to decrease futile cycling between glucose and glucose 6 phosphate in hepatocytes under low-glucose conditions, and to decrease the lag between a rise in intracellular glucose levels and the onset of glucose phosphorylation in both hepatocytes and pancreatic beta cells (Brocklehurst et al. 2004; Shiota et al. 1999)."
BMGC_PW0655,BMG_PW3002,,,The adaptor protein Frs2 (Fibroblast growth factor receptor substrate 2) can mediate the prolonged activation of the MAPK (ERK) cascade.
BMGC_PW0656,BMG_PW3003,,,ARMS (Ankyrin-Rich Membrane Spanning/Kidins 220) is a 220kD tetraspanning adaptor protein which becomes rapidly tyrosine phosphorylated by active Trk receptors. ARMS is another adaptor protein which is involved in the activation of Rap1 and the subsequent prolonged activation of the MAPK cascade.
BMGC_PW0657,BMG_PW3005,,,"Multiple steps, including C-strand resection, telomerase-mediated elongation, and C-strand synthesis are involved in processing and maintaining the telomere. Though this module posits a linear transit for the steps, in humans it is not well understood how these steps are coordinated and what other events may be involved. Telomeric DNA can form higher order structures. Electron microscopy of telomeric DNA isolated from human cells provided evidence for lariat-type structures termed telomeric loops, or t-loops (Griffith et al., 1999). t-loops are proposed to result from the invasion of the 3' G-rich single strand overhang into the double stranded telomeric TTAGGG repeat tract. The function of the t-loop is presumed to be the masking of the 3' telomeric overhang. Multiple protein factors can bind telomeric DNA and likely contribute to dynamic, higher order structures."
BMGC_PW0658,BMG_PW3007,,,"HIV enters cells by fusion at the cell surface, that results in a productive infection. The envelope (Env) protein of HIV mediates entry. Env is composed of a surface subunit, gp120, and a transmembrane subunit, gp41, which assemble as heterotrimers on the virion surface.The trimeric, surface gp120 protein (SU) on the virion engages CD4 on the host cell, inducing conformational changes that promote binding to select chemokine receptors CCR5 and CXCR4. The sequential interplay between SU, CD4 and chemokine coreceptors prompts a conformational change in the transmembrane gp41. This coiled coil protein, assembled as a trimer on the virion membrane, springs open to project three peptide fusion domains that 'harpoon' the lipid bilayer of the target cell. A hairpin structure (also referred to as a ""coiled coil bundle"") is subsequently formed when the extracellular portion of gp41 collapses, and this hairpin formation promotes the fusion of virion and target cell membranes by bringing them into close proximity. Virion and target cell membrane fusion leads to the release of HIV viral cores into the cell interior."
BMGC_PW0659,BMG_PW3009,,,"The degradation of cyclin B1, which appears to occur at the mitotic spindle, is delayed until the metaphase /anaphase transition by the spindle assembly checkpoint and is required in order for sister chromatids to separate (Geley et al. 2001;Hagting et al, 2002)."
BMGC_PW0660,BMG_PW3010,,,"Cdh1 is degraded by the APC/C during in G1 and G0. This auto-regulation may contribute to reducing the levels of Cdh1 levels during G1 and G0 (Listovsky et al., 2004)."
BMGC_PW0661,BMG_PW3011,,,Emi1 destruction in early mitosis requires the SCF beta-TrCP ubiquitin ligase complex. Binding of beta-TrCP to Emi1 occurs in late prophase and requires phosphorylation at the DSGxxS consensus motif as well as Cdk mediated phosphorylation. A two-step mechanism has been proposed in which the phosphorylation of Emi1 by Cdc2 occurs after the G2-M transition followed soon after by binding of beta-TrCP to the DSGxxS phosphorylation sites. Emi1 is then poly-ubiquitinated and degraded by the 26S proteasome.
BMGC_PW0662,BMG_PW3012,,,"The Anaphase Promoting Complex or Cyclosome (APC/C) functions during mitosis to promote sister chromatid separation and mitotic exit through the degradation of mitotic cyclins and securin. This complex is also active in interphase insuring the appropriate length of the G1 phase (reviewed in Peters, 2002). The APC/C contains at least 12 subunits and functions as an ubiquitin-protein ligase (E3) promoting the multiubiquitination of its target proteins (see Gieffers et al., 2001). In the ubiquitination reaction, ubiquitin is activated by the formation of a thioester bond with the (E1) ubiquitin activating enzyme then transferred to a cysteine residue within the ubiquitin conjugating enzyme (E2) and ultimately to a lysine residue within the target protein, with the aid of ubiquitin-protein ligase activity of the APC/C. The ubiquitin chains generated are believed to target proteins for destruction by the 26S proteasome (Reviewed in Peters, 1994 ) The activity of the APC/C is highly periodic during the cell cycle and is controlled by a combination of regulatory events. The APC/C is activated by phosphorylation and the regulated recruitment of activating subunits and is negatively regulated by sequestration by kinetochore-associated checkpoint proteins. The Emi1 protein associates with Cdh1 and Cdc20, inhibiting the APC/C between G1/S and prophase. RSSA1 may play a similar role in ihibiting the APC during early mitosis. Following phosphorylation of the APC/C core subunits by mitotic kinases, the activating subunit, Cdc20 is recruited to the APC/C and is responsible for mitotic activities, including the initiation of sister chromatid separation and the timing of exit from mitosis (See Zachariae and Nasmyth, 1999). Substrates of the Cdc20:APC/C complex, which are recognized by a motif known as the destruction box (D box) include Cyclin A, Nek2, Securin and Cyclin B. Degradation of Securin and Cyclin B does not occur until the mitotic spindle checkpoint has been satisfied (see Castro et al. 2005). Cdc20 is degraded late in mitosis (Reviewed in Owens and Hoyt, 2005). At this time the activating subunit, Cdh1, previously maintained in an inactive phosphorylated state by mitotic kinases, is dephosphorylated and associates with and activates the APC/C. The APC/C:Cdh1 complex recognizes substrates containing a D box, a KEN box (Pfleger and Kirschner, 2000) or a D box activated (DAD) domain (Castro et al., 2002) sequence and promotes the ordered degration of mitotic cyclins and other mitotic proteins culminating with its own ubiquitin-conjugating enzyme (E2) subunit UbcH10 (Rape et al., 2006). This ordered degradation promotes the stability of Cyclin A at the end of G1. This stabilization, in turn, promotes the phosphorylation of Cdh1 and its abrupt dissociation from the APC/C, allowing accumulation of cyclins for the next G1/S transition (Sorensen et al., 2001)."
BMGC_PW0663,BMG_PW3013,,,"The separation of sister chromatids in anaphase requires the destruction of the anaphase inhibitor, securin. Securin associates with and inactivates the protease, separase. Separase cleaves the cohesin subunit, Scc1 that is responsible for the cohesion of sister chromatids (reviewed in Nasmyth et al., 2000). Securin destruction begins at metaphase after the mitotic spindle checkpoint has been satisfied (Hagting et al., 2002)."
BMGC_PW0664,BMG_PW3014,,,"From late mitosis through G1 phase APC/C:Cdh1 insures the continued degradation of the mitotic proteins and during mitotic exit and G1 its substrates include Cdc20, Plk1, Aurora A, Cdc6 and Geminin (see Castro et al., 2005). Rape et al. have recently demonstrated that the order in which APC/C targeted proteins are degraded is determined by the processivity of multiubiquitination of these substrates. Processive substrates acquire a polyubiquitin chain upon binding to the APC/C once and are degraded. Distributive substrates bind, dissociate and reassociate with the APC/C multiple times before acquiring an ubiquitin chain of sufficient length to insure degradation. In addition, distributive substrates that dissociate from the APC/C with short ubiquitin chains are targeted for deubiquitination (Rape et al., 2006)."
BMGC_PW0665,BMG_PW3015,,,"Cyclin A, functions in mitosis as well as DNA replication and is degraded in the interim by the APC/C to permit normal chromosome segregation, cell division, and the onset of S phase (see Lukas and Bartek, 2004). Cyclin A is initially degraded early in mitosis by APC/C:Cdc20 when the spindle checkpoint is still active and degradation of securin and cyclin B is inhibited."
BMGC_PW0666,BMG_PW3016,,,"PAPS (3'-phosphoadenosine-5'-phosphosulfate), which functions as a sulfate donor in the cell, is synthesized from sulfate and two molecules of ATP in a two-step process (Robbins & Lipmann 1958) catalyzed in vertebrates by a bifunctional enzyme (Venkatachalam et al. 1998). PAPS synthesis takes place in the cytosol, and it is either consumed there in the sulfonation of a variety of hormones and xenobiotics, or it is transported to the Golgi apparatus and consumed in the synthesis of proteoglycans like chondroitin sulfate. Two isoforms of the human bifunctional enzyme are known, mutations in one of which are associated with defects in proteoglycan biosynthesis (Girard et al. 1998, ul Haque et al. 1998)."
BMGC_PW0667,BMG_PW3017,,,"After the primers are synthesized on the G-Rich strand, Replication Factor C binds to the 3'-end of the initiator DNA to trigger polymerase switching. The non-processive nature of pol alpha catalytic activity and the tight binding of Replication Factor C to the primer-template junction presumably lead to the turnover of the pol alpha:primase complex. After the Pol alpha-primase primase complex is displaced from the primer, the proliferating cell nuclear antigen (PCNA) binds to form a ""sliding clamp"" structure. Replication Factor C then dissociates, and DNA polymerase delta binds and catalyzes the processive synthesis of DNA."
BMGC_PW0668,BMG_PW3018,,,"Once polymerase switching from pol alpha to pol delta is complete the processive synthesis of a short run of DNA called an Okazaki fragment begins. DNA synthesis is discontinuous and as the extending Okazaki fragment reaches the RNA primer, this primer is folded into a single-stranded flap, which is removed by endonucleases. The process of extension is completed by the ligation of adjacent Okazaki fragments."
BMGC_PW0669,BMG_PW3019,,,"Due to the antiparallel nature of DNA, DNA polymerization is unidirectional, and one strand is synthesized discontinuously. This strand is called the lagging strand. Although the polymerase switching on the lagging strand is very similar to that on the leading strand, the processive synthesis on the two strands proceeds quite differently. Short DNA fragments, about 100 bases long, called Okazaki fragments are synthesized on the RNA-DNA primers first. Strand-displacement synthesis occurs, whereby the primer-containing 5'-terminus of the adjacent Okazaki fragment is folded into a single-stranded flap structure. This flap structure is removed by endonucleases, and the adjacent Okazaki fragments are joined by DNA ligase."
BMGC_PW0670,BMG_PW3020,,,"DNA polymerases are not capable of de novo DNA synthesis and require synthesis of a primer, usually by a DNA-dependent RNA polymerase (primase) to begin DNA synthesis. In eukaryotic cells, the primer is synthesized by DNA polymerase alpha:primase. First, the DNA primase portion of this complex synthesizes approximately 6-10 nucleotides of RNA primer and then the DNA polymerase portion synthesizes an additional 20 nucleotides of DNA. There have been reports that TRF1 inhibits this activity at telomeres, though the mechanism and physiological relevance of this inhibition remain to be elucidated."
BMGC_PW0671,BMG_PW3021,,,"Two endonucleases, Dna2 and flap endonuclease 1 (FEN-1), are responsible for resolving the nascent flap structure (Tsurimoto and Stillman 1991). The Dna2 endonuclease/helicase in yeast is a monomer of approximately 172 kDa. Human FEN-1 is a single polypeptide of approximately 42 kDa. Replication Protein A regulates the switching of endonucleases during the removal of the displaced flap (Tsurimoto et al.1991)."
BMGC_PW0672,BMG_PW3022,,,"One of the mysteries of Gag protein involvement in HIV virion assembly is how the proteins are targeted to the proper membrane for budding. Infectious retroviruses do not bud from all of the available membrane surfaces within an infected cell, but primarily from the plasma membrane, which constitutes a small proportion of the total membrane surface in most cells. In polarized cells, the sites of budding are further restricted to the basolateral membrane."
BMGC_PW0673,BMG_PW3023,,,"Evidence suggests that the RNA molecules used for the synthesis of Gag and Gag-Pro-Pol are not the same molecules that are packaged into virions. Gag proteins do not appear to aggregate around and capture the RNA contained in the polyribosome from which they emerged, but rather bind to and ultimately encapsidate free transcripts elsewhere. During the replication of retroviruses, large numbers of Gag molecules must be generated to serve as precursors to the structural proteins of the virions. Retroviruses have developed a mechanism that permits expression of the Gag protein at high levels relative to the protein sequences encoded in the pro and pol genes, while retaining coregulated expression. This linkage results from the use of the same initiation codon in the same mRNA to express the gag, pro, and pol genes. Translation of this RNA leads occasionally to synthesis of a fusion protein that is usually called the Gag-Pol precursor but is now more appropriately called the Gag-Pro-Pol precursor"
BMGC_PW0674,BMG_PW3024,,,"The 3 pathways of complement activation converge on the cleavage of C3 by C3 convertases. C3 convertase cleaves C3 into C3a and C3b - a central step of complement activation. C3a remains in the fluid phase and acts as an anaphylatoxin, whereas C3b can form additional C3 convertases hastening the production of C3b. Besides, C3b binds to C3 convertases to form C5 convertase, which can act as an opsonin, or is degraded into fragments which cannot form an active convertase."
BMGC_PW0675,BMG_PW3025,,,"Virion assembly packages all the components required for infectivity. These steps include two copies of the positive sense genomic viral RNA, cellular tRNALys, the viral envelope (Env) protein, the Gag polyprotein, and the three viral enzymes: protease (PR), reverse transcriptase (RT), and integrase (IN). The viral enzymes are packaged as domains within the Gag-Pro-Pol polyprotein."
BMGC_PW0676,BMG_PW3027,,,"Vpr has been implicated in multiple processes during HIV-1 replication, including nuclear import of the pre-integration complex (PIC)(Heinzinger et al., 1994), apoptosis (Stewart et al., 1997) and induction of cell cycle G2/M arrest (He et al., 1995; Re et al., 1995; Zhao et al., 1996). Interactions between Vpr and host nucleoporins (importin) appear to facilitate the nuclear import of the PIC (Popov et al., 1998; Vodicka et al., 1998) while interactions between Vpr the adenine nucleotide transporter (ANT) protein at the inner mitochondrial membrane may contribute to release of apoptosis factors by promoting permeabilization of the mitochondrial outer membrane (Jacotot et al., 2000). Vpr induces cell cycle G2/M arrest by promoting hyperphosphorylation of Cdk1/Cdc2 (Re et al., 1995; Zhao et al., 1996). However, it is unclear which protein(s) Vpr interacts with to cause this effect. For recent reviews, see, (Li et al., 2005; Zhao, Bukrinsky, and Elder, 2005). Progression of cells from G2 phase of the cell cycle to mitosis is a tightly regulated cellular process that requires activation of the Cdk1/Cdc2 kinase, which determines onset of mitosis in all eukaryotic cells. The activity of Cdk1/Cdc2 is regulated in part by the phosphorylation status of tyrosine 15 (Tyr15) on Cdk1/Cdc2, which is phosphorylated by Wee1 kinase during late G2 and is rapidly dephosphorylated by the Cdc25 tyrosine phosphatase to trigger entry into mitosis. These Cdk1/Cdc2 regulators are the downstream targets of two well-characterized G2/M checkpoint pathways which prevent cells from entering mitosis when cellular DNA is damaged or when DNA replication is inhibited. It is clear that Vpr induces cell cycle G2/M arrest by promoting Tyr15 phosphorylation of Cdk1/Cdc2 both in human and fission yeast cells (Elder et al., 2000; Re et al., 1995; Zhao et al., 1996), which modulates host cell cycle machinery to benefit viral survival or replication. Although some aspects of Vpr-induced G2/M arrest resembles induction of host cellular checkpoints, increasing evidence suggests that Vpr induces cell cycle G2 arrest through a mechanism that is to some extent different from the classic G2/M checkpoints. One the unique features distinguishing Vpr-induced G2 arrest from the classic checkpoints is the role of phosphatase 2A (PP2A) in Vpr-induced G2 arrest (Elder, Benko, and Zhao, 2002; Elder et al., 2001; Masuda et al., 2000). Interestingly, PP2A is targeted by a number of other viral proteins including SV40 small T antigen, polyomavirus T antigen, HTLV Tax and adenovirus E4orf4. Thus an in-depth understanding of the molecular mechanisms underlying Vpr-induced G2 arrest will provide additional insights into the basic biology of cell cycle G2/M regulation and into the biological significance of this effect during host-pathogen interactions."
BMGC_PW0677,BMG_PW3029,,,"Genotoxic stress caused by DNA damage or stalled replication forks can lead to genomic instability. To guard against such instability, genotoxically-stressed cells activate checkpoint factors that halt or slow cell cycle progression. Among the pathways affected are DNA replication by reduction of replication origin firing, and mitosis by inhibiting activation of cyclin-dependent kinases (Cdks). A key factor involved in the response to stalled replication forks is the ATM- and rad3-related (ATR) kinase, a member of the phosphoinositide-3-kinase-related kinase (PIKK) family. Rather than responding to particular lesions in DNA, ATR and its binding partner ATRIP (ATR-interacting protein) sense replication fork stalling indirectly by associating with persistent ssDNA bound by RPA. These structures would be formed, for example, by dissociation of the replicative helicase from the leading or lagging strand DNA polymerase when the polymerase encounters a DNA lesion that blocks DNA synthesis. Along with phosphorylating the downstream transducer kinase Chk1 and the tumor suppressor p53, activated ATR modifies numerous factors that regulate cell cycle progression or the repair of DNA damage. The persistent ssDNA also stimulates recruitment of the RFC-like Rad17-Rfc2-5 alternative clamp-loading complex, which subsequently loads the Rad9-Hus1-Rad1 complex onto the DNA. The latter '9-1-1' complex serves to facilitate Chk1 binding to the stalled replication fork, where Chk1 is phosphorylated by ATR and thereby activated. Upon activation, Chk1 can phosphorylate additional substrates including the Cdc25 family of phosphatases (Cdc25A, Cdc25B, and Cdc25C). These enzymes catalyze the removal of inhibitory phosphate residues from cyclin-dependent kinases (Cdks), allowing their activation. In particular, Cdc25A primarily functions at the G1/S transition to dephosphorylate Cdk2 at Thr 14 and Tyr 15, thus positively regulating the Cdk2-cyclin E complex for S-phase entry. Cdc25A also has mitotic functions. Phosphorylation of Cdc25A at Ser125 by Chk1 leads to Cdc25A ubiquitination and degradation, thus inhibiting DNA replication origin firing. In contrast, Cdc25B and Cdc25C regulate the onset of mitosis through dephosphorylation and activation of Cdk1-cyclin B complexes. In response to replication stress, Chk1 phosphorylates Cdc25B and Cdc25C leading to Cdc25B/C complex formation with 14-3-3 proteins. As these complexes are sequestered in the cytoplasm, they are unable to activate the nuclear Cdk1-cyclin B complex for mitotic entry. These events are outlined in the figure. Persistent single-stranded DNA associated with RPA binds claspin (A) and ATR:ATRIP (B), leading to claspin phosphorylation (C). In parallel, the same single-stranded DNA:RPA complex binds RAD17:RFC (D), enabling the loading of RAD9:HUS1:RAD1 (9-1-1) complex onto the DNA (E). The resulting complex of proteins can then repeatedly bind (F) and phosphorylate (G) CHK1, activating multiple copies of CHK1."
BMGC_PW0678,BMG_PW3030,,,"The activity of the APC/C must be appropriately regulated during the cell cycle to ensure the timely degradation of its substrates. Of particular importance is the conversion from APC/C:Cdc20 to APC/C:Cdh1 in late anaphase. Phosphorylation of both the APC/C complex and Cdh1 regulate this conversion. During mitosis, several APC/C subunits are phosphorylated increasing the activity of APC/C:Cdc20. However, phosphorylation of Cdh1 by mitotic Cyclin:Cdk complexes prevents it from activating the APC/C. Dephosphorylation of Cdh1 in late anaphase by Cdc14a results in the activation of APC/C:Cdh1 (reviewed in Castro et al, 2005)."
BMGC_PW0679,BMG_PW3031,,,"The APC/C is activated by either Cdc20 or Cdh1. While both activators associate with the APC/C, they do so at different points in the cell cycle and their binding is regulated differently (see Zachariae and Nasmyth, 1999). Cdc20, whose protein levels increase as cells enter into mitosis and decrease upon mitotic exit, only associates with the APC/C during M phase. Cdh1 associates with the APC/C in G1. This interaction is inhibited at other times by Cdk1 phosphorylation."
BMGC_PW0680,BMG_PW3032,,,"Following phosphorylation of the APC/C core subunits by mitotic kinases, the activating protein, Cdc20 is recruited to the APC and promotes the multiubiquitination and subsequent degradation of the mitotic cyclins (Cyclin A and Cyclin B) as well as the protein securin which functions in sister chromatid cohesion. Timely degradation of these proteins is essential for sister chromatid separation and the proper timing of exit from mitosis (See Zachariae and Nasmyth, 1999). Cdc20 is degraded late in mitosis (Reviewed in Owens and Hoyt, 2005)"
BMGC_PW0681,BMG_PW3033,,,"Phosphorylation of APC subunits is required for Cdc20 mediated activation by of the APC/C at the metaphase anaphase transition (Kramer et al., 2000). While the kinases responsible for phosphorylation in vivo have not been determined with certainty, both Plk1 and Cyclin B:Cdc2 have been implicated in this process."
BMGC_PW0682,BMG_PW3034,,,"The phosphorylation of Emi1, which is required for its degradation in mitosis, appears to involve both Plk1 and Cdk1."
BMGC_PW0683,BMG_PW3035,,,"APC/C:Cdc20 is first activated at the prometaphase/metaphase transition through phosphorylation of core subunits of the APC/C by mitotic kinases as well as recruitment of the APC/C activator protein Cdc20. APC/C:Cdc20 promotes the multiubiquitination and ordered degradation of Cyclin A and Nek2 degradation in prometaphase followed by Cyclin B and securin in metaphase (Reviewed in Castro et al., 2005)."
BMGC_PW0684,BMG_PW3036,,,DNA Replication is regulated accurately and precisely by various protein complexes. Many members of the MCM protein family are assembled into the pre-Replication Complexes (pre-RC) at the end of M phase of the cell cycle. DNA helicase activity of some of the MCM family proteins are important for the unwinding of DNA and initiation of replication processes. This section contains four events which have been proved in different eukaryotic experimental systems to involve various proteins for this essential step during DNA Replication.
BMGC_PW0685,BMG_PW3037,,,"In the body, aspirin (acetylsalicylic acid) is hydrolyzed to salicylate (ST). ST can then be hydroxylated to yield gentisic acid, conjugated with glucuronate, or conjugated with glycine to yield molecules that are excreted by the kidneys. The third of these conjugation processes is annotated here. It is the major route of ST catabolism and accounts for 20–65% of the products (Hutt et al, 1986). The conjugation proceeds in two steps. First, ST and ATP react with coenzyme A to form salicylate-CoA (ST-CoA), AMP, and pyrophosphate in a reaction catalyzed by xenobiotic/medium-chain fatty acid:CoA ligase (Vessey et al. 2003). Second, ST-CoA and glycine react to form salicyluric acid and Coenzyme A (Mawal and Qureshi 1994)."
BMGC_PW0686,BMG_PW3040,,,"In order to facilitate the transport of incompletely spliced HIV-1 transcripts, Rev shuttles between the cytoplasm and nucleus using host cell transport mechanisms (reviewed in Li et al. 2005). Nuclear import appears to be achieved by the association of Rev with importin-beta and B23 and docking at the nuclear pore through interactions between importin-beta and nucleoporins. The dissociation of Rev with the import machinery and the subsequent export of Rev-associated HIV-1 mRNA complex requires Ran-GTP. Ran GTP associates with importin-beta, displacing its cargo. Crm1 associates with the Rev:RNA complex and Ran:GTP and is believed to interact with nucleoporins facilitating docking of the RRE-Rev-CRM1-RanGTP complex to the nuclear pore and the translocation of the complex across the nuclear pore complex. In the cytoplasm, RanBP1 associates with Ran-GTP causing the Crm1-Rev-Ran-GTP complex to disassemble. The Ran GAP protein promotes the hydrolysis of RanGTP to Ran GDP. The activities of Ran GAP in the cytoplasm and Ran-GEF, which converts RAN-GDP to Ran-GTP in the nucleus, produce a gradient of Ran-GTP/GDP required for this shuttling of Rev and other cellular transport proteins."
BMGC_PW0687,BMG_PW3041,,,"Neurotrophin-TRK complexes can be internalized and enter signalling vesicles, which travel retrogradely over long distances from distal nerve terminals to neuronal cell bodies. Such retrograde signalling by neurotrophin-TRK complexes regulates survival, synaptogenesis and maintenance of proper neural connectivity. The neurotrophin-TRK complex may use three distinct internalization pathways. Although Clathrin-mediated endocytosys appears to be the major internalization route, it is controversial whether it also represents the dominant pathway for retrograde transport and signalling. Pyncher-mediated endocytosis might be more relevant in this regard. Moreover, also caveolin-mediated endocytosis may play a role in NGF-TrkA internalization. Retrograde transport of TRKs is microtubule-dependent: TRKs remain activated and bound to neurotrophins during retrograde transport. The current view is reflected in the signalling endosome model. It is a specialized vesicle containing ligand (NGF, BDNF) bound to its activated TRK receptor, together with activated downstream signalling proteins, transported by motor proteins (dyneins) from nerve terminals to remote cell bodies, where the receptors trigger signalling cascades."
BMGC_PW0688,BMG_PW3043,,,"Chondroitin sulfate (CS) is a sulfated glycosaminoglycan (GAG). CS chains are unbranched polysaccharides of varying length containing two alternating monosaccharides: D-glucuronic acid (GlcA) and N-acetyl-D-galactosamine (GalNAc). The chains are usually attached to proteins forming a proteoglycan. CS is an important structural component of cartilage due to it's ability to withstand compression. It is also a widely used dietary supplement for osteoarthritis. When some of the GlcA residues are epimerized into L-iduronic acid (IdoA) the resulting disaccharide is then referred to as dermatan sulfate (DS) (Silbert & Sugumaran 2002). DS is the most predominant GAG in skin but is also found in blood vessels, heart valves, tendons, and the lungs. It may play roles in cardiovascular disease, tumorigenesis, infection, wound repair and fibrosis (Trowbridge & Gallo 2002)."
BMGC_PW0689,BMG_PW3044,,,"Like Cyclin A, NIMA-related kinase 2A (Nek2A) is degraded during pro-metaphase in a checkpoint-independent manner."
BMGC_PW0690,BMG_PW3045,,,APC:CDC20 mediates the degradation of a number of cell cycle proteins including Cyclin A and Nek2A.
BMGC_PW0691,BMG_PW3046,,,"Autophosphorylated EGFR tyrosine residues are docking sites for many downstream effectors in EGFR signaling. The adaptor protein GRB2 binds to phosphotyrosine residues in the C-tail of EGFR through its SH2 domain. GRB2 is constitutively associated with SOS, a guanine nucleotide exchange factor of RAS. GRB2 binding to phosphorylated EGFR results in the recruitment of SOS to the plasma membrane where it comes in proximity to RAS. This mechanism has been seen to be the model for RAS activation."
BMGC_PW0692,BMG_PW3047,,,"The process for translation of a protein destined for the endoplasmic reticulum (ER) branches from the canonical cytoslic translation process at the point when a nascent polypeptide containing a hydrophobic signal sequence is exposed on the surface of the cytosolic ribosome:mRNA:peptide complex. The signal sequence mediates the interaction of this complex with a cytosolic signal recognition particle (SRP) to form a complex which in turn docks with an SRP receptor complex on the ER membrane. There the ribosome complex is transferred from the SRP complex to a translocon complex embedded in the ER membrane and reoriented so that the nascent polypeptide protrudes through a pore in the translocon into the ER lumen. Translation, which had been halted by SRP binding, now resumes, the signal peptide is cleaved from the polypeptide, and elongation proceeds, with the growing polypeptide oriented into the ER lumen."
BMGC_PW0693,BMG_PW3048,,,"Dopamine- and cAMP-regulated phosphoprotein, Mr 32 kDa (DARPP-32), was identified as a major target for dopamine and protein kinase A (PKA) in striatum. Recent advances now indicate that regulation DARPP-32 phosphorylation provides a mechanism for integrating information arriving at dopaminoceptive neurons, in multiple brain regions, via a variety of neurotransmitters, neuromodulators, neuropeptides, and steroid hormones. Activation of PKA or PKG stimulates DARPP-32 phosphorylation at Thr34, converting DARPP-32 into a potent inhibitor of protein phosphatase-1 (PP-1). DARPP-32 is also phosphorylated at Thr75 by Cdk5, converting DARPP-32 into an inhibitor of PKA. Thus, DARPP-32 has the unique property of being a dual-function protein, acting either as an inhibitor of PP-1 or of PKA."
BMGC_PW0694,BMG_PW3049,,,"GAB1 is recruited to the activated EGFR indirectly, through GRB2. GAB1 acts as an adaptor protein that enables formation of an active PIK3, through recruitment of PIK3 regulatory subunit PIK3R1 (also known as PI3Kp85), which subsequently recruits PIK3 catalytic subunit PIK3CA (also known as PI3Kp110). PIK3, in complex with EGFR, GRB2 and GAB1, catalyzes phosphorylation of PIP2 and its conversion to PIP3, which leads to the activation of the AKT signaling."
BMGC_PW0695,BMG_PW3050,,,"GRB2 can bind EGFR directly or through another SH2-containing protein, SHC1. This association leads to RAS activation."
BMGC_PW0696,BMG_PW3051,,,"The HIV-1 Vpu protein promotes the degradation of the CD4 receptor by recruiting an SCF like ubiquitination complex that promotes CD4 degradation. Vpu links beta-TrCP to CD4 at the ER membrane through interactions with beta-TrCP and the cytoplasmic tail of CD4. The SKP1 component of the SCF complex is then recruited to the Vpu:beta-TrCP:CD4 promoting ubiquitination and subsequent proteasome-mediated degradation of CD4 (reviewed in Li et al., 2005). Vpu has also been shown to also increases progeny virus secretion from infected cells. Although the precise role of Vpu in this process is not yet known, it may affect ion conductive membrane pore formation and/or interference with TASK-1, an acid-sensitive K+ channel that inhibits virion release in some cells (see references in Li et al., 2005)."
BMGC_PW0697,BMG_PW3052,,,"The HIV-1 accessory protein Vif (Viral infectivity factor) is required for the efficient infection of primary cell populations (e.g., lymphocytes and macrophages) and 'non-permissive' cell lines. Vif neutralises the host DNA editing enzyme, APOBEC3G, in the producer cell. Indeed, in the absence of a functional Vif, APOBEC3G is selectively incorporated into the budding virions and in the next cycle of infection leads to the deamination of deoxycytidines (dC) within the minus-strand cDNA during reverse transcription (Sheehy et al 2003; Li et al., 2005 ; Stopak et al. 2003). Deamination changes cytidine to uracil and thus results in G to A transitions and stop codons in the provirus. The aberrant cDNAs produced in the infected cell can either be integrated in form of non-functional proviruses or degraded. Vif counteracts the antiviral activity of APOBEC3G by associating directly with it and promoting its polyubiquitination and degradation by the 26S proteasome. Vif binds APOBEC3G and recruits it into an E3 ubiquitin-enzyme complex composed by the cytoplasmic proteins Cullin5, Rbx, ElonginC and ElonginB (Yu et al., 2003) . Thus, in the presence of Vif, APOBEC3G incorporation into the virion is minimal."
BMGC_PW0698,BMG_PW3054,,,"Nuclear import of Rev involves the cellular proteins including importin-beta and B23 and is mediated by an arginine-rich nuclear localization signal (NLS) within the RNA binding domain of the Rev protein. The NLS of Rev associates with importin- beta as well as B23 which has been shown to function in the nuclear import of ribosomal proteins. The Rev-importin beta-B23 complex associates with the nuclear pore through interactions between importin beta and nucleoporin. Upon entry into the nucleus, Ran-GTP associates with importin beta resulting in in the disassembly of the importin beta-Rev-B23 complex and the release of Rev cargo."
BMGC_PW0699,BMG_PW3055,,,Telomerase acts as reverse transcriptase in the elongation of telomeres (Smogorzewska and de Lange 2004).
BMGC_PW0700,BMG_PW3056,,,"In one model of Vpr mediated induction of apoptosis, Vpr acts directly on the mitochondrial permeability transition pore complex through its interaction with adenine nucleotide translocator (ANT). This interaction promotes the permeabiliztion of the mitochondrial membranes resulting in the release of cytochrome c and apoptosis-inducing factors."
BMGC_PW0701,BMG_PW3057,,,Vpr appears to function in anchoring the PIC to the nuclear envelope. This anchoring likely involves interactions between Vpr and host nucleoporins.
BMGC_PW0702,BMG_PW3058,,,Overexpression of human or murine ZBP1 (DAI) in human embryonic kidney 293T cells (HEK293T) activated NF-kB-dependent promoter in a dose-dependent manner. Two RHIM-contaning kinases RIP1 and RIP3 are implicated in ZBP1-induced NFkB activation (Rebsamen M et al 2009; Kaiser WJ et al 2008).
BMGC_PW0703,BMG_PW3059,,,"Serotonin is synthesized in the serotonergic neurons in the central nervous system and the enterochrommaffin cells of the gastroinetstinal system. Serotonin is loaded into the clathrin sculpted monoamine transport vesicles. The vesicles are docked, primed and release after the change in the membrane potential that activates voltage gated calcium channels and the reponse by several proetins to the changes in intracellular Ca2+ increase leads to fusion of the vesicle and release of serotonin into the synapse."
BMGC_PW0704,BMG_PW3060,,,"Noradrenalin release cycle consists of reacidification of the empty clathrin sculpted monoamine transport vesicle, loading of dopamine into reacidified clathrin coated monamine transport vesicle, conversion of dopamine into Noradrenalin, docking and priming of the noradrenalin synaptic veiscle and then release of noradrenalin synaptic vesicle. In the peripheral nervous system in the peripheral nervous system noradrenalin is stored in large and small dense vesicles and is realesed from large vesicles."
BMGC_PW0705,BMG_PW3061,,,"Human immunodeficiency virus (HIV) Nef is a membrane-associated protein decreasing surface expression of CD4, CD28, and major histocompatibility complex class I on infected cells. Nef also strongly down-modulates surface expression of the beta-chain of the CD8alphabeta receptor by accelerated endocytosis, while CD8 alpha-chain expression is less affected. Mutational analysis of the cytoplasmic tail of the CD8 beta-chain indicates that an FMK amino acid motif is critical for the Nef-induced endocytosis. Although independent of CD4, endocytosis of the CD8 beta-chain is abrogated by the same mutations in Nef that affect CD4 down-regulation, suggesting common molecular interactions. The ability to down-regulate the human CD8 beta-chain was conserved in HIV-1, HIV-2, and simian immunodeficiency virus SIVmac239 Nef and required an intact AP-2 complex."
BMGC_PW0706,BMG_PW3062,,,"Regulation of receptor tyrosine kinase (RTK) activity is implicated in the control of almost all cellular functions. One of the best understood RTKs is epidermal growth factor receptor (EGFR). Growth factors can bind to EGFR and activate it to initiate signalling cascades within the cell. EGFRs can also be recruited to clathrin-coated pits which can be internalised into endocytic vesicles. From here, EGFRs can either be recycled back to the plasma membrane or directed to lysosomes for destruction.This provides a mechanism by which EGFR signalling is negatively regulated and controls the strength and duration of EGFR-induced signals. It also prevents EGFR hyperactivation as commonly seen in tumorigenesis. The proto-oncogene Cbl can negatively regulate EGFR signalling. The Cbl family of RING-type ubiquitin ligases are able to poly-ubiquitinate EGFR, an essential step in EGFR degradation. All Cbl proteins have a unique domain that recognises phosphorylated tyrosine residues on activated EGFRs. They also direct the ubiquitination and degradation of activated EGFRs by recruiting ubiquitin-conjugation enzymes. Cbl proteins function by specifically targeting activated EGFRs and mediating their down-regulation, thus providing a means by which signaling processes can be negatively regulated. Cbl also promotes receptor internalization via it's interaction with an adaptor protein, CIN85 (Cbl-interacting protein of 85kDa). CIN85 binds to Cbl via it's SH3 domain and is enhanced by the EGFR-induced tyrosine phosphorylation of Cbl. The proline-rich region of CIN85 interacts with endophilins which are regulatory components of clathrin-coated vesicles (CCVs). Endophilins bind to membranes and induce membrane curvature, in conjunction with other proteins involved in CCV formation. The rapid recruitment of endophilin to the activated receptor complex by CIN85 is the mechanism which controls receptor internalization."
BMGC_PW0707,BMG_PW3063,,,"STING (stimulator of IFN genes; also known as MITA/ERIS/MPYS/TMEM173) is an endoplasmic reticulum (ER) resident, which is required for effective type I IFN production in response to nucleic acids. Indeed, select pathogen-derived DNA or RNA were shown to activate STING in human and mouse cells (Ishikawa H and Barber GN 2008; Ishikawa H et al. 2009; Sun W et al. 2009; Prantner D et al. 2010). Importantly, in vitro studies have shown that STING is essential for Mycobacterium tuberculosis (Manzanillo PS et al. 2012), Plasmodium falciparum (Sharma S et al. 2011) and human immunodeficiency virus (HIV) induced type I IFN production [Yan N et al 2010]. Mycobacterium tuberculosis, plasmodium falciparum and HIV are three deadliest pathogens, which kill millions of people each year worldwide. STING has been also implicated in type I IFN response which was stimulated by fusion of viral and target-cell membrane in a manner independent of DNA, RNA and viral capsid [Holm CK et al 2012]. Under steady state conditions, STING is positioned at the translocon complex within the ER membrane. However upon stimulation with intracellular DNA it translocates from ER to perinuclear vesicles via the Golgi by mechanisms that remain unclear (Ishikawa H and Barber GN 2008; Sun W et al. 2009; Ishikawa H et al. 2009; Saitoh T et al. 2009). Mouse Sting trafficking in dsDNA-stimulated mouse embryonic fibroblasts (MEF) cells was found to depend on autophagy-related gene 9a (Atg9a) (Saitoh T et al. 2009). STING was reported to function as a signaling adaptor or coreceptor in response to cytosolic dsDNA (Unterholzner L et al. 2010; Zhang Z et al. 2011). STING was also shown to function as a direct DNA sensor to induce the innate immune response in human telomerase fibroblasts (hTERT-BJ1) and murine embryonic fibroblasts (MEFs) (Abe T et al. 2013). Additionally, STING is thought to function as a direct sensor of cyclic dinucleotides. STING was shown to interact directly with c-di-GMP in human embryonic kidney HEK293T cell lysates (Burdette DL et al. 2011). Once STING is stimulated, its C-terminus serves as a signaling scaffold to recruit IRF3 and TBK1, which leads to TBK1-dependent phosphorylation of IRF3 (Tanaka Y and Chen ZJ 2012). Mouse, but not human STING, can also bind vascular disrupting agents 5,6-dimethylxanthenone-4-acetic acid (DMXAA) and the antiviral small molecule 10-carboxymethyl-9-acridanone (CMA) to induce type I IFN production, suggesting a species-specific drug effect on the STING-mediated host response (Conlon J et al. 2013; Cavlar T et al. 2013)."
BMGC_PW0708,BMG_PW3064,,,"Presence of pathogen-associated DNA in cytosol induces type I IFN production. Several intracellular receptors have been implicated to some degree. These include DNA-dependent activator of interferon (IFN)-regulatory factors (DAI) (also called Z-DNA-binding protein 1, ZBP1), absent in melanoma 2 (AIM2), RNA polymerase III (Pol III), IFN-inducible protein IFI16, leucine-rich repeat flightless interacting protein-1 (LRRFIP1), DEAH-box helicases (DHX9 and DHX36), DEAD-box helicase DDX41, meiotic recombination 11 homolog A (MRE11), DNA-dependent protein kinase (DNA-PK), cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING). Detection of cytosolic DNA requires multiple and possibly redundant sensors leading to activation of the transcription factor NF-kappaB and TBK1-mediated phosphorylation of the transcription factor IRF3. Cytosolic DNA also activates caspase-1-dependent maturation of the pro-inflammatory cytokines interleukin IL-1beta and IL-18. This pathway is mediated by AIM2."
BMGC_PW0709,BMG_PW3065,,,"8p11 myeloproliferative syndrome (EMS) is an aggressive disorder that is associated with a translocation event at the FGFR1 gene on chromosome 8p11. Typical symptoms upon diagnosis include eosinophilia and associated T-cell lymphoblastic lymphoma; the disease rapidly advances to acute leukemia, usually of myeloid lineage. At present the only effective treatment is allogenic stem cell transplantation (reviewed in Jackson, 2010). At the molecular level, EMS appears to be caused by translocation events on chromosome 8 that create gene fusions between the intracellular domain of FGFR1 and an N-terminal partner gene that encodes a dimerization domain. The resulting fusion protein dimerizes in a ligand-independent fashion based the N-terminal domain provided by the partner protein and stimulates constititutive downstream FGFR1 signaling without altering the intrisic kinase activity of the receptor. To date, 11 partner genes have been identified: ZMYM2, FGFR1OP, FGFR1OP2, HERVK, TRIM24, CUX1, BCR, CEP110, LRRFIP1, MYO18A and CPSF6, although not all have been functionally characterized (reviewed in Jackson, 2010, Turner and Grose, 2010; Wesche, 2011). Where examined, cell lines carrying FGFR1 fusion genes have been shown to be transforming and to support IL3-independent proliferation through anti-apoptotic, prosurvival pathways(Lelievre, 2008; Ollendorff, 1999; Chase, 2007; Guasch, 2001; Wasag 2011; Roumiantsev, 2004; Demiroglu, 2001; Smedley, 1999). Signaling appears to occur predominantly through PLCgamma, PI3K and STAT signaling, with a more minor contribution from MAPK activation. Because the fusion proteins lack the FRS2-binding site, the mechanism of MAPK activation is unclear. Recruitment of GRB2:SOS1 through recruitment of SHC is one possibility (Guasch, 2001)."
BMGC_PW0710,BMG_PW3067,,,"Unlike FGFR2 and FGFR3, FGFR1 appears not to be a frequent target of activating point mutations (reviewed in Wesche, 2011; Turner and Grose, 2010). Germline point mutations at residue P252 have been identified in Pfeiffer syndrome (reviewed in Webster and Donoghue, 1997; Burke, 1998; Cunningham, 2007) while mutation of the same residue arising somatically has been identified in melanoma and lung cancer (Ruhe, 2007; Davies, 2005). Two kinase domain mutations have been characterized in glioblastoma (Rand, 2005; Network TCGA, 2008), both at positions that are also mutated in an autosomal disorder in one of the FGFR family members (Muenke, 1994; Bellus, 1995a; Bellus, 2000; Tavormina, 1995a; Tavormina, 1999)."
BMGC_PW0711,BMG_PW3068,,,"The FGFR1 gene has been shown to be subject to activating mutations, chromosomal rearrangements and gene amplification leading to a variety of proliferative and developmental disorders depending on whether these events occur in the germline or arise somatically (reviewed in Webster and Donoghue, 1997; Burke, 1998; Cunningham, 2007; Wesche, 2011; Greulich and Pollock, 2011). Many of the resulting mutant FGFR1 proteins can dimerize and promote signaling in a ligand-independent fashion, although signal transduction may still be amplified in the presence of ligand (reviewed in Turner and Gross, 2010; Greulich and Pollock, 2011; Wesche et al, 2011)."
BMGC_PW0712,BMG_PW3069,,,"Autosomal dominant mutations in FGFR2 are associated with the development of a range of skeletal disorders including Beare-Stevensen cutis gyrata syndrome, Pfeiffer syndrome, Jackson-Weiss syndrome, Crouzon syndrome and Apert Syndrome (reveiwed in Burke, 1998; Webster and Donoghue 1997; Cunningham, 2007). Activating point mutations have also been identified in FGFR2 in ~15% of endometrial cancers, as well as to a lesser extent in ovarian and gastric cancers (Dutt, 2008; Pollock, 2007; Byron, 2010; Jang, 2001). Activating mutations in FGFR2 are thought to contribute to receptor activation through diverse mechanisms, including constitutive ligand-independent dimerization (Robertson, 1998), expanded range and affinity for ligand (Ibrahimi, 2004b; Yu, 2000) and enhanced kinase activity (Byron, 2008; Chen, 2007). FGFR2 amplifications have been identified in 10% of gastric cancers, where they are associated with poor prognosis diffuse cancers (Hattori, 1996; Ueda, 1999; Shin, 2000; Kunii, 2008) , and in ~1% of breast cancers (Turner, 2010; Tannheimer, 2000). FGFR2 amplification often occur in conjunction with deletions of C-terminal exons, resulting in expression of a internalization- and degradation-resistant form of the receptor (Takeda, 2007; Cha, 2008, 2009). Signaling through overexpressed FGFR2 shows evidence of being ligand-independent and sensitive to FGFR inhibitors (Lorenzi, 1997; Takeda, 2007; Cha, 2009). More recently, FGFR2 fusion proteins have been identified in a number of cancers; these are thought to form constitutive ligand-independent dimers based on the dimerization domains of the 3' fusion partners and contribute to cellular proliferation and tumorigenesis in a kinase-inhibitor sensitive manner (Wu, 2013; Arai, 2013; Seo, 2012; reviewed in Parker, 2014)."
BMGC_PW0713,BMG_PW3071,,,"Activating point mutations in FGFR3 are found in the extracellular ligand-binding domain, the transmembrane region and the tyrosine kinase domain and are believed to result in ligand-independent activation of the receptor (Webster and Donoghue, 1996; Wenbster, 1997). These mutations, although initially characterized in the context of autosomal skeletal disorders, are now being identified in a range of cancers including bladder, cervical, breast, prostate, head and neck, and multiple myeloma (reviewed in Wesche, 2011)."
BMGC_PW0714,BMG_PW3072,,,"This module describes the biogenesis of organelles. Organelles are subcellular structures of distinctive morphology and function. The organelles of human cells include: mitochondria, endoplasmic reticulum, Golgi apparatus, vacuoles, nucleus, (auto)phagosome, centriole, lysosome, melanosome, myofibril, nucleolus, peroxisome, cilia (in some cell types), proteasome, ribsome, and transport vesicles."
BMGC_PW0715,BMG_PW3074,,,"Inositol phosphates such as IP4, IP5 and IP6 are converted to an even wider variety of IPs including the di- and triphospho inositol phosphates, also known as pyrophosphates (Irvine & Schell 2001, Alcazar-Romain & Wente 2008, York 2006, Monserrate and York 2010, Ho et al. 2002, Saiardi et al. 2001, Draskovic et al. 2008, Choi et al. 2007, Caffrey et al. 2000, Leslie et al. 2002)."
BMGC_PW0716,BMG_PW3076,,,"Inositol phosphates IP2, IP and the six-carbon cyclic alcohol inositol (Ins) are produced by various phosphatases and the inositol-3-phosphate synthase 1 (ISYNA1) (Ju et al. 2004, Ohnishi et al. 2007, Irvine & Schell 2001, Bunney & Katan 2010)."
BMGC_PW0717,BMG_PW3081,,,"An array of inositol trisphosphate (IP3) and tetrakisphosphate (IP4) molecules are synthesised by the action of various kinases and phosphatases in the cytosol (Irvine & Schell 2001, Bunney & Katan 2010)."
BMGC_PW0718,BMG_PW3085,,,"The normal development of the pancreas during gestation has been intensively investigated over the past decade especially in the mouse (Servitja and Ferrer 2004; Chakrabarti and Mirmira 2003). Studies of genetic defects associated with maturity onset diabetes of the young (MODY) has provided direct insight into these processes as they take place in humans (Fajans et al. 2001). During embryogenesis, committed epithelial cells from the early pancreatic buds differentiate into mature endocrine and exocrine cells. It is helpful to schematize this process into four consecutive cellular stages, to begin to describe the complex interplay of signal transduction pathways and transcriptional networks. The annotations here are by no means complete - factors in addition to the ones described here must be active, and even for the ones that are described, only key examples of their regulatory effects and interactions have been annotated. It is also important to realize that in the human, unlike the mouse, cells of the different stages can be present simultaneously in the developing pancreas and the linear representation of these developmental events shown here is an over-simplification of the actual developmental process (e.g., Sarkar et al. 2008). The first stage of this process involves the predifferentiated epithelial cells of the two pancreatic anlagen that arise from the definitive endoderm at approximately somite stages 11-15 and undergo budding from somite stages 20-22. This period corresponds to gestational days 8.75-9.5 in the mouse, and 26 in the human. Pancreatic buds subsequently coalesce to form a single primitive gland, while concomitantly a ductal tree lined by highly proliferative epithelial cells is formed. A subset of such epithelial cells is thought to differentiate into either endocrine or acinar exocrine cells. A third cellular stage is defined by the endocrine-committed progenitors that selectively express the basic helix-loop-helix transcription factor NEUROG3. NEUROG3 is known to activate a complex transcriptional network that is essential for the specification of endocrine cells. Many transcription factors that are activated by NEUROG3 are also involved in islet-subtype cellular specification and in subsequent stages of differentiation of endocrine cells. This transient cellular stage thus leads to the generation of all known pancreatic endocrine cells, including insulin-producing beta-cells, and glucagon-producing alpha cells, the final stage of this schematic developmental process. The diagram below summarizes interactions that take place between transcription factors and transcription factor target genes during these cellular stages, and shows cases where there is both functional evidence that a transcription factor is required for the target gene to be expressed, and biochemical evidence that this interaction is direct. We also describe instances where a signaling pathway is known to regulate a transcription factor gene in this process, even if the intervening signaling pathway is not fully understood."
BMGC_PW0719,BMG_PW3086,,,"The role of autophosphorylation sites on PDGF receptors are to provide docking sites for downstream signal transduction molecules which contain SH2 domains. The SH2 domain is a conserved motif of around 100 amino acids that can bind a phosphorylated tyrosine residue. These downstream molecules are activated upon binding to, or phosphorylated by, the receptor kinases intrinsic to PDGF receptors. Some of the dowstream molecules are themselves enzymes, such as phosphatidylinositol 3'-kinase (PI3K), phospholipase C (PLC-gamma), the Src family of tyrosine kinases, the tyrosine phosphatase SHP2, and a GTPase activating protein (GAP) for Ras. Others such as Grb2 are adaptor molecules which link the receptor with downstream catalytic molecules."
BMGC_PW0720,BMG_PW3087,,,Trk receptors can either be activated by neurotrophins or by two G-protein-coupled receptors (GPCRs) although the biological relevance of GPCRs remains to be shown.
BMGC_PW0721,BMG_PW3088,,,"TRK receptors can also be activated by at least two G-protein-coupled receptors (GPCR), the adenosine A2a receptor and the PACAP type I receptor, without involvement of neurotrophins. Activity of both receptors is mediated by G proteins that activate adenyl cyclase. How this leads to TRKA activation has not been fully elucidated, although a SRC-family tyrosine kinase and intracellular Ca2+ appear to play a role. TRKA activation through GPCRs occurs with slow kinetics (over 1 hr adenosine or PACAP treatment is required) in an intracellular location (probably the Golgi apparatus), and requires transcriptional and protein synthesis events that may influence the processing and activation of the receptors. GPCR-mediated transactivation of TRK receptors causes the preferential activation of AKT versus ERKs. This leads to a cell survival response."
BMGC_PW0722,BMG_PW3089,,,"Trk receptors signal from the plasma membrane and from intracellular membranes, particularly from early endosomes. Signalling from the plasma membrane is fast but transient; signalling from endosomes is slower but long lasting. Signalling from the plasma membrane is annotated here. TRK signalling leads to proliferation in some cell types and neuronal differentiation in others. Proliferation is the likely outcome of short term signalling, as observed following stimulation of EGFR (EGF receptor). Long term signalling via TRK receptors, instead, was clearly shown to be required for neuronal differentiation in response to neurotrophins."
BMGC_PW0723,BMG_PW3091,,,"During G1, the activity of cyclin-dependent kinases (CDKs) is kept in check by the CDK inhibitors (CKIs) p27 and p21, thereby preventing premature entry into S phase (see Guardavaccaro and Pagano, 2006). These two CKIs are degraded in late G1 phase by the ubiquitin pathway (Pagano et al., 1995; Bloom et al., 2003) involving the ubiquitin ligase SCF(Skp2) (Tsvetkov et al., 1999; Carrano et al., 1999; Sutterluty et al., 1999, Bornstein et al., 2003) and the cell-cycle regulatory protein Cks1 (Ganoth et al., 2001; Spruck et al 2001; Bornstein et al., 2003). Recognition of p27 by SCF(Skp2) and its subsequent ubiquitination is dependent upon Cyclin E/A:Cdk2- mediated phosphorylation at Thr 187 of p27 (Montagnoli et al., 1999). There is evidence that Cyclin A/B:Cdk1 complexes can also bind and phosphorylate p27 on Th187 (Nakayama et al., 2004). Degradation of polyubiquitinated p27 by the 26S proteasome promotes the activity of CDKs in driving cells into S phase. (Montagnoli et al., 1999; Tsvetkov et al., 1999, Carrano et al 1999). The mechanism of SCF(Skp2)-mediated degradation of p21 is similar to that of p27 in terms of its requirements for the presence of Cks1 and of Cdk2/cyclin E/A (Bornstein et al.,2003; Wang et al., 2005). In addition, as observed for p27, p21 phosphorylation at a specific site (Ser130) stimulates its ubiquitination. In contrast to p27, however, ubiquitination of p21 can take place in the absence of phosphorylation, although with less efficiency (Bornstein et al.,2003). SCF(Skp2)-mediated degradation of p27/p21 continues from late G1 through M-phase. During G0 and from early G1 to G1/S, Skp2 is degraded by the anaphase promoting complex/Cyclosome and its activator Cdh1 [APC/C(Cdh1)] (Bashir et al, 2004; Wei et al, 2004). The tight regulation of APC/C(Cdh1) activity ensures the timely elimination Skp2 and, thus, plays a critical role in controlling the G1/S transition. APC/C(Cdh1) becomes active in late M-phase by the association of unphosphorylated Cdh1 with the APC/C. APC/C(Cdh1) remains active until the G1/S phase at which time it interacts with the inhibitory protein, Emi1 (Hsu et al., 2002). Inhibition of APC/C(Cdh1) activity results in an accumulation of cyclins, which leads to the phosphorylation and consequently to a further inactivation of Cdh1 at G1/S (Lukas et al., 1999). Finally, to make the inactivation of APC/C(Cdh1) permanent, Cdh1 and its E2, namely Ubc10, are eliminated in an auto-ubiquitination event (Listovsky et al., 2004; Rape and Kirschner, 2004). At G1/S, Skp2 reaccumulates as Cdh1 is inactivated, thus allowing the ubiquitination of p21 and p27 and resulting in a further increase in CDK activity."
BMGC_PW0724,BMG_PW3092,,,"Neurotrophins utilize multiple pathways to activate ERKs (ERK1 and ERK2), a subgroup of the large MAP kinase (MAPK) family, from the plasma membrane. The major signalling pathways to ERKs are via RAS, ocurring from caveolae in the plasma membrane or from clathrin-coated vesicles, and via RAP1, taking place in early endosomes. Whereas RAS activation by NGF is transient, RAP1 activation by NGF is sustained for hours."
BMGC_PW0725,BMG_PW3093,,,"RIT and RIN are two small guanine nucleotide binding proteins that share more than 50% sequence identity with RAS, including highly conserved core effector domains. Unlike RAS, the C termini of RIT and RIN lack a typical prenylation motif (CAAX, XXCC, or CXC) required for the association of RAS proteins with the plasma membrane. RIT is expressed in all tissues, whereas RIN is neuron-specific. They have similar signalling properties and are activated by NGF through unknown exchange factors. They signal to ERKs and p38 MAP kinase. They mainly lead to p38 activation via the BRAF-MEK kinase cascade."
BMGC_PW0726,BMG_PW3094,,,"Carbohydrate is a major component of the human diet, and includes starch (amylose and amylopectin) and disaccharides such as sucrose, lactose, maltose and, in small amounts, trehalose. The digestion of starch begins with the action of amylase enzymes secreted in the saliva and small intestine, which convert it to maltotriose, maltose, limit dextrins, and some glucose. Digestion of the limit dextrins and disaccharides, both dietary and starch-derived, to monosaccharides - glucose, galactose, and fructose - is accomplished by enzymes located on the luminal surfaces of enterocytes lining the microvilli of the small intestine (Van Beers et al. 1995)."
BMGC_PW0727,BMG_PW3095,,,"FGFR3 is a receptor tyrosine kinase of the FGF receptor family, known to have a negative regulatory effect on long bone growth. Somatically, some of the same activating mutations are associated with hypochondroplasia, multiple myeloma, and cervical and vesical carcinoma."
BMGC_PW0728,BMG_PW3096,,,"Dominant mutations in the fibroblast growth factor receptor 2 (FGFR2) gene have been identified as causes of four phenotypically distinct craniosynostosis syndromes, including Crouzon, Jackson- Weiss, Pfeiffer, and Apert syndromes. FGFR2 binds a number of different FGFs preferentially, as illustrated in this pathway. FGFR is probably activated by NCAM very differently from the way by which it is activated by FGFs, reflecting the different conditions for NCAM-FGFR and FGF-FGFR interactions. The affinity of FGF for FGFR is approximately 10e6 times higher than that of NCAM for FGFR. Moreover, in the brain NCAM is constantly present on the cell surface at a much higher (micromolar) concentration than FGFs, which only appear transiently in the extracellular environment in the nanomolar range."
BMGC_PW0729,BMG_PW3097,,,"The vertebrate fibroblast growth factor receptor 1 (FGFR1) is alternatively spliced generating multiple variants that are differentially expressed during embryo development and in the adult body. The restricted expression patterns of FGFR1 isoforms, together with differential expression and binding of specific ligands, leads to activation of common FGFR1 signal transduction pathways, but may result in distinctively different biological responses as a result of differences in cellular context. FGFR1 isoforms are also present in the nucleus in complex with various fibroblast growth factors where they function to regulate transcription of target genes. FGFR is probably activated by NCAM very differently from the way by which it is activated by FGFs, reflecting the different conditions for NCAM-FGFR and FGF-FGFR interactions. The affinity of FGF for FGFR is approximately 10e6 times higher than that of NCAM for FGFR. Moreover, in the brain NCAM is constantly present on the cell surface at a much higher (micromolar) concentration than FGFs, which only appear transiently in the extracellular environment in the nanomolar range."
BMGC_PW0730,BMG_PW3098,,,"FGFR4 is expressed mainly in mature skeletal muscle, and disruption of FGFR4 signaling interrupts limb muscle formation in vertebrates."
BMGC_PW0731,BMG_PW3099,,,"This pathway depicts the binding of an experimentally-verified range of ligands to FGFR1b. While binding affinities may vary considerably within this set, the ligands listed have been established to bring about receptor activation at their reported physiological concentrations."
BMGC_PW0732,BMG_PW3100,,,"This pathway depicts the binding of an experimentally-verified range of ligands to FGFR3b. While binding affinities may vary considerably within this set, the ligands listed have been established to bring about receptor activation at their reported physiological concentrations."
BMGC_PW0733,BMG_PW3101,,,"This pathway depicts the binding of an experimentally-verified range of ligands to FGFR3c. While binding affinities may vary considerably within this set, the ligands listed have been established to bring about receptor activation at their reported physiological concentrations."
BMGC_PW0734,BMG_PW3102,,,"This pathway depicts the binding of an experimentally-verified range of ligands to FGFR1c. While binding affinities may vary considerably within this set, the ligands listed have been established to bring about receptor activation at their reported physiological concentrations."
BMGC_PW0735,BMG_PW3103,,,FGF23 is a member of the endocrine subfamily of FGFs. It is produced in bone tissue and regulates kidney functions. Klotho is essential for endogenous FGF23 function as it converts FGFR1c into a specific FGF23 receptor.
BMGC_PW0736,BMG_PW3104,,,"This pathway depicts the binding of an experimentally-verified range of ligands to FGFR2c. While binding affinities may vary considerably within this set, the ligands listed have been established to bring about receptor activation at their reported physiological concentrations."
BMGC_PW0737,BMG_PW3105,,,"This pathway depicts the binding of an experimentally-verified range of ligands to FGFR2b. While binding affinities may vary considerably within this set, the ligands listed have been established to bring about receptor activation at their reported physiological concentrations."
BMGC_PW0738,BMG_PW3106,,,"The mechanism of connexin assembly into connexons has been well characterized. Two different types of connexons can be formed. A connexon containing six identical connexin molecules is referred to as an homomeric connexon, while a connexon containing at least two different connexin molecules is referred to as an heteromeric connexon. The connexin molecules making up an heteromeric connexon appear to belong to only one subgroup (alpha or beta); heteromeric connexons containing both alpha and beta subunits have not yet been observed. Indeed, an intrinsic signal in four amino acid positions appears to confer different physicochemical characteristics to certain connexins in the alpha and beta groups (Lagr et al., 2003). These intrinsic signals are Cx specific, however (see Gemel et al., 2006). Therefore, additional yet unknown signals are required to regulate connexin compatibility and hetero-oligomerization. The identification of the subcellular location at which gap junction assembly occurs has proven difficult. One explanation for this difficulty may be that the location of oligomerization for each connexon varies depending upon Cx type or cell type. Oligomerization has been observed after ER membrane insertion (Cx43, Cx32, Cx26) (Falk et al., 1997; Ahmad et al., 1999; Ahmad and Evans, 2002), in the ER-Golgi-intermediate compartment (ERGIC) (Cx32) (Diez et al. 1999) and inside the trans-Goligi network (Cx43) (Musil and Goodenough, 1993)."
BMGC_PW0739,BMG_PW3107,,,"Connexins follow the classical secretory transport route from the ER to the plasma membrane: ER -> ERGIC -> Golgi -> TGN (Trans Golgi Network) -> PM (Plasma Membrane). All connexins assemble or oligomerize into hexameric connexons. The site of assembly varies and depends on Cx isoform, or cell type (see Koval et al., 2006). Oligomerization of connexins has been observed during ER membrane insertion (Cx32), just after exit from the ER, in the ER-Golgi-intermediate compartment (Cx26) and inside the Trans-Golgi Network (Cx43) (Falk et al. 1997; Ahmad et al. 1999; Musil and Goodenough 1993; Diez et al. 1999)."
BMGC_PW0740,BMG_PW3108,,,"Gap junctions are intercellular communication channels formed from Cx (connexin) protein subunits (see Segretain and Falk 2004 and Evans et al. 2006 for comprehensive reviews). Connexins are transported to the plasma membrane after oligomerizing into hexameric assemblies called hemichannels (CxHcs) or connexons. Connexons dock head-to-head in the extracellular space with opposing hexameric channels located in the plasma membranes of neighbouring cells. The double membrane channel or gap junction generated directly links the cytoplasms of interacting cells and facilitates the integration and co-ordination of cellular signalling, metabolism, secretion and contraction. In addition to their role in intercellular communication, connexon hemichannels coordinate the release of ATP, glutamate, NAD+ and prostaglandin E2 from the cells. CxHcs open in response to various types of external changes, including mechanical, shear, ionic and ischaemic stress. The trafficking of gap junctions involves (1) synthesis of connexin polypeptides at endoplasmic reticulum membranes, (2) oligomerization into homomeric- and heteromeric gap junction connexons (hemi-channels), (3) passage through the Golgi stacks, (4) intracellular storage within Trans Golgi membranes, (5) trafficking along microtubules, (6) insertion of connexons into the plasma membrane, (7) lateral diffusion of connexons in the plasma membrane, (8) aggregation of individual gap junction channels into plaques, (9) stabilization of peripheral microtubule plus-ends by binding to Cx43-based gap junctions, (10) internalization of the channel plaque leading to cytoplasmic annular junctions, and (11) complete degradation via lysosomal and proteasomal pathways (see Segretain and Falk 2004). Aspects of gap assembly are described here."
BMGC_PW0741,BMG_PW3110,,,"The assembly of gap junctions involves (1) synthesis of connexin polypeptides at endoplasmic reticulum membranes, (2) oligomerization into homomeric- and heteromeric gap junction connexons (hemi-channels), (3) passage through the Golgi stacks, (4) intracellular storage within Trans Golgi membranes, (5) trafficking along microtubules, (6) insertion of connexons into the plasma membrane, (7) lateral diffusion of connexons in the plasma membrane, (8) aggregation of individual gap junction channels into plaques, and (9) stabilization of peripheral microtubule plus-ends by binding to Cx43-based gap junctions (see Segretain and Falk, 2004.)"
BMGC_PW0742,BMG_PW3111,,,"Following connexon oligomerization, the hemichannels must be transported to the plasma membrane. This has been shown to occur in transport vesicles called ""cargo containers"". Most of post-Golgi cargo containers have a diameter of of 50- 200 nm (Lauf et al., 2002). Recently direct transport of connexins to GJ assembly sides has been described (Shaw et al., 2007). Besides microtuble-dependent trafficking, a microtubule-independent delivery pathway may exist as concluded from studies using the secretory transport inhibitor, Brefeldin A (Musil and Goodenough 1993; De Sousa et al. 1993; Laird et al. 1995)."
BMGC_PW0743,BMG_PW3112,,,"The half-life of Cx is very short (1 to 5h) compared to other junctional proteins (Laird et al., 1995 ; Fallon and Goudenough, 1981). Connexins are targeted for degradation by the proteasome and the lysosome. Degradation appears to involve the phosphorylation of Connexins as well as their interactions with other proteins (Piehl et al., 2007)."
BMGC_PW0744,BMG_PW3113,,,"In the endoplasmic reticulum, glycosyl transferases modify NOTCH precursors by glycosylating conserved serine and threonine residues in EGF repeats of NOTCH. O-fucosyl transferase POFUT1 fucosylates NOTCH serine and threonine residues that conform to the consensus sequence C2-X(4-5)-S/T-C3, where C2 and C3 are the second and third cysteine residue within the EGF repeat, and X(4-5) is four to five amino acid residues of any type (Yao et al. 2011, Stahl et al. 2008, Wang et al. 2001, Shao et al. 2003). O-glucosyl transferase POGLUT1, mammalian homolog of the Drosophila enzyme Rumi, adds a glucosyl group to conserved serine residues within the EGF repeats of NOTCH. The consensus sequence for POGLUT1-mediated glucosylation is C1-X-S-X-P-C2, where C1 and C2 are the first and second cysteine residue in the EGF repeat, respectively, while X represents any amino acid (Acar et al. 2008, Fernandez-Valdivia et al. 2011). Both fucosylation and glucosylation of NOTCH receptor precursors are essential for functionality."
BMGC_PW0745,BMG_PW3114,,,"In humans, the NOTCH protein family has four members: NOTCH1, NOTCH2, NOTCH3 and NOTCH4. NOTCH1 protein was identified first, as the product of a chromosome 9 gene translocated in T-cell acute lymphoblastic leukemia that was homologous to Drosophila Notch (Ellisen et al. 1991). At the same time, rat Notch1 was cloned (Weinmaster et al. 1991), followed by cloning of mouse Notch1, named Motch (Del Amo et al. 1992). NOTCH2 protein is the product of a gene on chromosome 1 (Larsson et al. 1994). NOTCH2 expression is differentially regulated during B-cell development (Bertrand et al. 2000). NOTCH2 mutations are a rare cause of Alagille syndrome (McDaniell et al. 2006). NOTCH3 is the product of a gene on chromosome 19. NOTCH3 mutations are the underlying cause of CADASIL, cerebral arteriopathy with subcortical infarcts and leukoencephalopathy (Joutel et al. 1996). NOTCH4, the last NOTCH protein discovered, is the product of a gene on chromosome 6 (Li et al. 1998). MicroRNAs play an important negative role in translation and/or stability of NOTCH mRNAs. MicroRNAs miR-34 (miR-34A, miR-34B and mi-R34C), whose transcription is directly induced by the tumor suppressor protein p53 (Chang et al. 2007, Raver-Shapira et al. 2007, He et al. 2007, Corney et al. 2007) bind and negatively regulate translation of NOTCH1 mRNA (Li et al. 2009, Pang et al. 2010, Ji et al. 2009) and NOTCH2 mRNA (Li et al. 2009). NOTCH1 mRNA translation is also negatively regulated by microRNAs miR-200B and miR-200C (Kong et al. 2010), as well as miR-449A, miR-449B and miR-449C (Marcet et al. 2011). Translation of NOTCH3 mRNA is negatively regulated by microRNAs miR-150 (Ghisi et al. 2011) and miR-206 (Song et al. 2009). Translation of NOTCH4 mRNA is negatively regulated by microRNAs miR-181C (Hashimoto et al. 2010) and miR-302A (Costa et al. 2009). The NOTCH2NL (Notch homolog 2 N-terminal-like) gene family includes four genes, NOTCH2NLA (Notch homolog 2 N-terminal-like A), NOTCH2NLB (Notch homolog 2 N-terminal-like B), NOTCH2NLC (Notch homolog 2 N-terminal-like), and NOTCH2NLR (Notch homolog 2 N-terminal-like R), which originated from the partial duplication of the first four exons and introns of the NOTCH2 gene and function to modulate NOTCH signaling (Fiddes et al. 2018, Florio et al. 2018, Suzuki et al. 2018, Lodewijk et al. 2020). Nascent NOTCH peptides are co-translationally targeted to the endoplasmic reticulum for further processing, followed by modification in the Golgi apparatus, before trafficking to the plasma membrane. Endoplasmic reticulum calcium ATPases, positively regulate NOTCH trafficking, possibly by contributing to accurate folding of NOTCH precursors (Periz et al. 1999)."
BMGC_PW0746,BMG_PW3115,,,"NOTCH undergoes final posttranslational processing in the Golgi apparatus (Lardelli et al. 1994, Blaumueller et al. 1997, Weinmaster et al. 1991, Weinmaster et al. 1992, Uyttendaele et al. 1996). Movement of NOTCH precursors from the endoplasmic reticulum to Golgi is controlled by SEL1L protein, a homolog of C. elegans sel-1. SEL1L localizes to the endoplasmic reticulum membrane and prevents translocation of misfolded proteins, therefore serving as a quality control check (Li et al. 2010, Sundaram et al. 1993, Francisco et al. 2010). Similarly, C. elegans sel-9 and its mammalian homolog TMED2 are Golgi membrane proteins that participate in quality control of proteins transported from Golgi to the plasma membrane. Translocation of a mutant C. elegans NOTCH homolog lin-12 from the Golgi to the plasma membrane is negatively regulated by sel-9 (Wen et al. 1999). A GTPase RAB6 positively controls NOTCH trafficking through Golgi (Purcell et al. 1999). Processing of mammalian NOTCH precursors in the Golgi typically involves the cleavage by FURIN convertase. Pre-NOTCH is a ~300 kDa protein, and cleavage by FURIN produces two fragments with approximate sizes of 110 kDa and 180 kDa. The 110 kDa fragment contains the transmembrane and intracellular domains of NOTCH and is known as NTM or NTMICD. The 189 kDa fragment contains NOTCH extracellular sequence and is known as NEC or NECD. The NTM and NEC fragments heterodimerize (Blaumueller et al. 1997, Logeat et al. 1998, Chan et al. 1998) and are held together by disulfide bonds and calcium ions (Rand et al. 2000, Gordon et al. 2009). An optional step in Pre-NOTCH processing in the Golgi is modification by fringe enzymes. Fringe enzymes are glycosyl transferases that initiate elongation of O-linked fucose on fucosylated peptides by addition of a beta 1,3 N-acetylglucosaminyl group, resulting in formation of disaccharide chains on NOTCH EGF repeats (GlcNAc-bet1,3-fucitol). Three fringe enzymes are known in mammals: LFNG (lunatic fringe), MFNG (manic fringe) and RFNG (radical fringe). LFNG shows the highest catalytic activity in modifying NOTCH (Bruckner et al. 2000, Moloney et al. 2000). Fringe-created disaccharide chains on NOTCH EGF repeats are further extended by B4GALT1 (beta-1,4-galactosyltransferase 1), which adds galactose to the N-acetylglucosaminyl group, resulting in formation of trisaccharide Gal-beta1,4-GlcNAc-beta1,3-fucitol chains (Moloney et al. 2000, Chen et al. 2001). Formation of trisaccharide chains is the minimum requirement for fringe-mediated modulation of NOTCH signaling, although fringe-modified NOTCH expressed on the cell surface predominantly contains tetrasaccharide chains on EGF repeats. The tetrasaccharide chains are formed by sialyltransferase(s) that add sialic acid to galactose, resulting in formation of Sia-alpha2,3-Gal-beta1,4-GlcNAc-beta1,3-fucitol (Moloney et al. 2000). Three known Golgi membrane sialyltransferases could be performing this function: ST3GAL3, ST3GAL4 and ST3GAL6 (Harduin-Lepers et al. 2001). The modification of NOTCH by fringe enzymes modulates NOTCH-signaling by increasing the affinity of NOTCH receptors for delta-like ligands, DLL1 and DLL4, while decreasing affinity for jagged ligands, JAG1 and JAG2."
BMGC_PW0747,BMG_PW3116,,,"In humans and other mammals the NOTCH gene family has four members, NOTCH1, NOTCH2, NOTCH3 and NOTCH4, encoded on four different chromosomes. Their transcription is developmentally regulated and tissue specific, but very little information exists on molecular mechanisms of transcriptional regulation. Translation of NOTCH mRNAs is negatively regulated by a number of recently discovered microRNAs (Li et al. 2009, Pang et al.2010, Ji et al. 2009, Kong et al. 2010, Marcet et al. 2011, Ghisi et al. 2011, Song et al. 2009, Hashimoto et al. 2010, Costa et al. 2009). The nascent forms of NOTCH precursors, Pre-NOTCH1, Pre-NOTCH2, Pre-NOTCH3 and Pre-NOTCH4, undergo extensive posttranslational modifications in the endoplasmic reticulum and Golgi apparatus to become functional. In the endoplasmic reticulum, conserved serine and threonine residues in the EGF repeats of NOTCH extracellular domain are fucosylated and glucosylated by POFUT1 and POGLUT1, respectively (Yao et al. 2011, Stahl et al. 2008, Wang et al. 2001, Shao et al. 2003, Acar et al. 2008, Fernandez Valdivia et al. 2011). In the Golgi apparatus, fucose groups attached to NOTCH EGF repeats can be elongated by additional glycosylation steps initiated by fringe enzymes (Bruckner et al. 2000, Moloney et al. 2000, Cohen et al. 1997, Johnston et al. 1997, Chen et al. 2001). Fringe-mediated modification modulates NOTCH signaling but is not an obligatory step in Pre-NOTCH processing. Typically, processing of Pre-NOTCH in the Golgi involves cleavage by FURIN convertase (Blaumueller et al. 1997, Logeat et al. 1998, Gordon et al. 2009, Rand et al. 2000, Chan et al. 1998). The cleavage of NOTCH results in formation of mature NOTCH heterodimers that consist of NOTCH extracellular domain (NEC i.e. NECD) and NOTCH transmembrane and intracellular domain (NTM i.e. NTMICD). NOTCH heterodimers translocate to the cell surface where they function in cell to cell signaling."
BMGC_PW0748,BMG_PW3117,,,"Src is believed to suppress gap junction communication by phosphorylating Cx43. The kinases c-Src (Giepmans et al. 2001; Sorgen et al. 2004), PKc (Lin et al. 2003) and MAPK (Mograbi et al. 2003) play an essential role in the phosphorylation of Cx which leads to its degradation. c-Src appears to associate with and phosphorylate Cx43 leading to closure of gap junctions. Evidence suggests that v-src may activate MAPK, which in turn phosphorylates Cx43 on serine sites leading to channel gating (Zhou et al. 1999)."
BMGC_PW0749,BMG_PW3118,,,"Small nuclear ribonucleoproteins (snRNPs) are crucial for pre-mRNA processing to mRNAs. Each snRNP contains a small nuclear RNA (snRNA) and an extremely stable core of seven Sm proteins. The U6 snRNA differs from the other snRNAs; it binds seven Sm-like proteins and its assembly does not involve a cytoplasmic phase. The snRNP biogenesis pathway for all of the other snRNAs is complex, involving nuclear export of snRNA, Sm-core assembly in the cytoplasm and re-import of the mature snRNP. The assembly of the snRNA:Sm-core is carried out by the survival of motor neurons (SMN) complex. The SMN complex stringently scrutinizes RNAs for specific features that define them as snRNAs and binds the RNA-binding Sm proteins."
BMGC_PW0750,BMG_PW3119,,,"In a healthy adult human, about 500 mg of cholesterol is converted to bile salts daily (Russell 2003). The major pathway for bile salt synthesis in the liver begins with the conversion of cholesterol to 7alpha-hydroxycholesterol. Bile salt synthesis can also begin with the synthesis of an oxysterol - 24-hydroxycholesterol or 27-hydroxycholesterol. In the body, the initial steps of these two pathways occur in extrahepatic tissues, generating intermediates that are transported to the liver and converted to bile salts via the 7alpha-hydroxycholesterol pathway. These extrahepatic pathways contribute little to the total synthesis of bile salts, but are thought to play important roles in cholesterol homeostasis (Javitt 2002)."
BMGC_PW0751,BMG_PW3120,,,"Dietary lipids such as long-chain triacylglycerols and cholesterol esters are digested in the stomach and small intestine to yield long-chain fatty acids, monoacylglycerols, glycerol and cholesterol through the action of a variety of lipases, and are then absorbed into enterocytes."
BMGC_PW0752,BMG_PW3122,,,"Spliced and unspliced viral mRNA in the cytoplasm are translated by host cell ribosomal translation machinery (reviewed in Kash, 2006). At least ten viral proteins are synthesized: HA, NA, PB1, PB2, PA, NP, NS1, NEP/NS2, M1, and M2. Viral mRNA translation is believed to be enhanced by conserved 5'UTR sequences that interact with the ribosomal machinery and at least one cellular RNA-binding protein, G-rich sequence factor 1 (GRSF-1), has been found to specifically interact with the viral 5' UTRs. (Park, 1995; Park, 1999). The viral NS1 protein and the cellular protein P58(IPK) enhance viral translation indirectly by preventing the activation of the translational inhibitor PKR (Salvatore, 2002; Goodman, 2006). The viral NS1 protein has also been proposed to specifically enhance translation through interaction with host poly(A)-binding protein 1 (PABP1) (Burgui, 2003). Simultaneously, host cell protein synthesis is downregulated in influenza virus infection through still uncharacterized mechanisms (Katze, 1986; Garfinkel, 1992; Kash, 2006). In most human influenza A strains (such as PR8), the PB1 mRNA segment is capable of producing a second protein, PB1-F2, from a short +1 open reading frame initiating downstream of the PB1 ORF initiation codon (Chen, 2001)."
BMGC_PW0753,BMG_PW3125,,,"In the liver, synthesis of bile acids and bile salts is initiated with the conversion of cholesterol to 7alpha-hydroxycholesterol and of 7alpha-hydroxycholesterol to 4-cholesten-7alpha-ol-3-one. The pathway then branches: hydroxylation of 4-cholesten-7alpha-ol-3-one to 4-cholesten-7alpha, 12alpha-diol-3-one leads ultimately to the formation of cholate, while its reduction to 5beta-cholestan-7alpha-ol-3-one leads to chenodeoxycholate formation. The amounts of substrate following each branch appear to be determined by abundance of the hydroxylase enzyme: in human liver, cholate synthesis predominates. In both branches, reactions in the cytosol, the mitochondrial matrix, and the peroxisomal matrix result in modifications to the ring structure, shortening and oxidation of the side chain, conversion to a Coenzyme A derivative, and conjugation with the amino acids glycine or taurine. In the body, glycocholate, taurocholate, glycochenodeoxycholate, and taurochenodeoxycholate are released from hepatocytes into the bile and ultimately into the lumen of the small intestine, where they function as detergents to solubilize dietary fats. The liver synthetic pathway also yields small amounts of bile acids, cholate and deoxycholate, which may play a feedback role in regulating the bile acid synthetic pathway (Russell 2003). These reactions are outlined in the figure below."
BMGC_PW0754,BMG_PW3126,,,"p75NTR can also form a receptor complex with the Nogo receptor (NgR). Such complexes mediates axonal outgrowth inhibitory signals of MDGIs (myelin-derived growth-inhibitors), such as Nogo66, myelin-associated glycoprotein (MAG), and oligodendrocyte myelin glycoprotein (OMGP)."
BMGC_PW0755,BMG_PW3127,,,"The NF-kB pathway is an important pro-survival signalling pathway activated by mature NGF, but not BDNF or NT-3, through p75NTR. It is unclear whether TRKA activity also affects NF-kB activation."
BMGC_PW0756,BMG_PW3128,,,"Once bound by either NGF or proNGF, p75NTR interacts with NRAGE, thus leading to phosphorylation and activation of JUN Kinase (JNK). JNK controls apoptosis in two ways: it induces transcription of pro-apoptotic genes, and directly activates the cell death machinery. Only NGF-bound p75NTR is shown here."
BMGC_PW0757,BMG_PW3129,,,"SC1 (Schwann Cell factor 1; also called PR domain zinc finger protein 4, PRDM4) interacts with an NGF:p75NTR complex and signals cell cycle arrest by regulating the levels of cyclin E."
BMGC_PW0758,BMG_PW3130,,,"p75NTR undergoes a process of regulated intramembrane proteolysis (RIP) similar to other transmembrane proteins such as NOTCH, beta-amyloid precursor protein (APP), and ERBB4. Each of these proteins is subjected to two sequential cleavages. The first one occurs in the extracellular part of the protein and is mediated by the metalloproteinase alpha-secretase which causes shedding of the extracellular domain. The second cleavage occurs in the intramembrane region and is mediated by gamma-secretase and causes release of the intracellular domain, ICD, and of a small peptide. The ICD often traffics to the nucleus and, in some instances (e.g. NOTCH), was found to act as transcriptional regulator. Whether the p75NTR ICD does translocate to the nucleus to regulate gene expression in a way similar to the NOTCH receptor remains to be seen. The alpha- and gamma-secretase mediated cleavage of p75 appears to be regulated by neurotrophin (NGF, BDNF) binding to TRKA or TRKB. p75NTR processing also occurs in response to MAG in cerebellar granule neurons."
BMGC_PW0759,BMG_PW3131,,,"p75NTR modulates axonal growth by regulating the activity of small GTPases like RHOA and RHOB, that control the state of actin polymerization. The best studied is RHOA. In its active, GTP-bound form, RHOA rigidifies the actin cytoskeleton, thereby inhibiting axonal elongation and causing growth cone collapse. Depending on the ligand that binds to it, p75NTR can either promote or inhibit axonal growth, Neurotrophin binding leads to inhibition of RHOA activity and axonal growth. Axonal growth inhibition is caused by myelin molecules named MDGIs (myelin-derived growth inhibitors), such as NOGO, MAG, OMGP. MDGIs bind to a complex made up of p75NTR and the NOGO receptor, causing RHOA activation and axonal growth inhibition."
BMGC_PW0760,BMG_PW3132,,,"Besides signalling through the tyrosine kinase receptors TRK A, B, and C, the mature neurotrophins NGF, BDNF, and NT3/4 signal through their common receptor p75NTR. NGF binding to p75NTR activates a number of downstream signalling events controlling survival, death, proliferation, and axonogenesis, according to the cellular context. p75NTR is devoid of enzymatic activity, and signals by recruiting other proteins to its own intracellular domain. p75 interacting proteins include NRIF, TRAF2, 4, and 6, NRAGE, necdin, SC1, NADE, RhoA, Rac, ARMS, RIP2, FAP and PLAIDD. Here we annotate only the proteins for which a clear involvement in p75NTR signalling was demonstrated. A peculiarity of p75NTR is the ability to bind the pro-neurotrophins proNGF and proBDNF. Proneurotrophins do not associate with TRK receptors, whereas they efficiently signal cell death by apoptosis through p75NTR. The biological action of neurotrophins is thus regulated by proteolytic cleavage, with proforms preferentially activating p75NTR, mediating apoptosis, and mature forms activating TRK receptors, to promote survival. Moreover, the two receptors are utilised to differentially modulate neuronal plasticity. For instance, proBDNF-p75NTR signalling facilitates LTD, long term depression, in the hippocampus (Woo NH, et al, 2005), while BDNF-TRKB signalling promotes LTP (long term potentiation). Many biological observations indicate a functional interaction between p75NTR and TRKA signaling pathways."
BMGC_PW0761,BMG_PW3133,,,"In the body, 24-hydroxycholesterol is synthesized in the brain, exported to the liver, and converted there to bile acids and bile salts. This pathway is only a minor source of bile acids and bile salts, but appears to be critical for the disposal of excess cholesterol from the brain (Bjorkhem et al. 1998; Javitt 2002). In the liver, conversion of 24-hydroxycholesterol to bile acids and bile salts is initiated with hydroxylation and oxidoreductase reactions to form 4-cholesten-7alpha,24(S)-diol-3-one. The pathway then branches: hydroxylation of 4-cholesten-7alpha,24(S)-diol-3-one to 4-cholesten-7alpha,12alpha,24(S)-triol-3-one leads ultimately to the formation of cholate, while its reduction to 5beta-cholestan-7alpha,24(S)-diol-3-one leads to chenodeoxycholate formation. In both branches, reactions in the cytosol, the mitochondrial matrix, and the peroxisomal matrix result in modifications to the ring structure, shortening and oxidation of the side chain, conversion to a Coenzyme A derivative, and conjugation with the amino acids glycine or taurine (Russell 2003). These reactions are outlined in the figure below. The final three reactions are identical to ones of bile salt synthesis initiated by 7alpha-hydroxylation and are shown as arrows with no substrates."
BMGC_PW0762,BMG_PW3134,,,"In the body, 27-hydroxycholesterol is synthesized in multiple tissues, exported to the liver, and converted there to bile acids and bile salts. This pathway is only a minor source of bile acids and bile salts, but may play a significant role particularly in the mobilization of cholesterol from lung phagocytes (Bjorkhem et al. 1994; Babiker et al. 1999; Javitt 2002). In the liver, conversion of 27-hydroxycholesterol to bile acids and bile salts is initiated with hydroxylation and oxidoreductase reactions to form 4-cholesten-7alpha,27-diol-3-one. The pathway then branches: hydroxylation of 4-cholesten-7alpha,27-diol-3-one to 4-cholesten-7alpha,12alpha,27-triol-3-one leads ultimately to the formation of cholate, while its reduction to 5beta-cholestan-7alpha,27-diol-3-one leads to chenodeoxycholate formation. In both branches, reactions in the cytosol, the mitochondrial matrix, and the peroxisomal matrix result in modifications to the ring structure, shortening and oxidation of the side chain, conversion to a Coenzyme A derivative, and conjugation with the amino acids glycine or taurine (Russell 2003). These reactions are outlined in the figure below. The final nine reactions are identical to ones of bile salt synthesis initiated by 7alpha-hydroxylation and are shown as arrows with no substrates."
BMGC_PW0763,BMG_PW3135,,,"In a healthy adult human, about 500 mg of cholesterol is converted to bile salts daily. Newly synthesized bile salts are secreted into the bile and released into the small intestine where they emulsify dietary fats (Russell 2003). About 95% of the bile salts in the intestine are recovered and returned to the liver (Kullak-Ublick et al. 2004; Trauner and Boyer 2002). The major pathway for bile salt synthesis in the liver begins with the conversion of cholesterol to 7alpha-hydroxycholesterol. Bile salt synthesis can also begin with the synthesis of an oxysterol - 24-hydroxycholesterol or 27-hydroxycholesterol. In the body, the initial steps of these two pathways occur in extrahepatic tissues, generating intermediates that are transported to the liver and converted to bile salts via the 7alpha-hydroxycholesterol pathway. These extrahepatic pathways contribute little to the total synthesis of bile salts, but are thought to play important roles in extrahepatic cholesterol homeostasis (Javitt 2002)."
BMGC_PW0764,BMG_PW3136,,,"The plasma membrane-associated Neuropilin receptors NRP-1 and -2 bind some of the VEGF proteins and associate with VEGF receptor proteins. NRP-1 binds VEGF-A165, -B, and PLGF-2; NRP-2 also binds VEGF-A165 and PLGF-2, as well as VEGF-A145 and -C. The Neurolipin receptors appear to act as cofactors for the VEGF receptors, increasing their affinities for specific VEGF ligands, although the importance of this function in vivo remains unclear (Neufeld et al. 2002)."
BMGC_PW0765,BMG_PW3137,,,"The VEGF family is encoded by seven genes (VEGF-A, B, C, D, E: PLGF (Placenta Growth Factor)-1, 2). Six isoforms of VEGF-A protein, containing 121, 145, 165, 183, 189, and 206 amino acid residues, and two isoforms of VEGF-B (167 and 186 residues) are specified by alternatively spliced mRNAs. The active form of each of these proteins is a homodimer. The specificities of the three VEGF tyrosine kinase receptors, VEGFR-1, VEGFR-2 and VEGFR-3, for these ligands are shown in the figure (Hicklin and Ellis 2005). All VEGF-A isoforms bind both VEGFR-1 and VEGFR-2; PLGF-1 and -2, and VEGF-B isoforms bind only VEGFR-1; VEGF-E binds VEGFR-2; and VEGF-C and -D bind both VEGFR-2 and -3. VEGF-D undergoes a complex series of post-translational modifications that results in secreted forms with increased activity toward VEGFR-3 and VEGFR-2. Two co-receptor proteins in the cell membrane, neuropilin (NRP)-1 and NRP-2, interact with VEGFR proteins to increase the affinity of the latter for their ligands (Neufeld et al.,2002). They differ from VEGFR proteins in not having intracellular signaling domains."
BMGC_PW0766,BMG_PW3138,,,"The Rho family of small guanine nucleotide binding proteins is one of seven phylogenetic branches of the Ras superfamily (Bernards 2005), which, besides Rho, Miro and RHOBTB3 also includes Ran, Arf, Rab and Ras families (Boureux et al. 2007). Miro GTPases and RHOBTB3 ATPase are sometimes described as Rho family members, but they are phylogenetically distinct (Boureux et al. 2007). Phylogenetically, RHO GTPases can be grouped into four clusters. The first cluster consists of three subfamilies: Rho, RhoD/RhoF and Rnd. The second cluster consists of three subfamilies: Rac, Cdc42 and RhoU/RhoV. The third cluster consists of the RhoH subfamily. The fourth cluster consists of the RhoBTB subfamily. Based on their activation type, RHO GTPases can be divided into classical (typical) and atypical (reviewed by Haga and Ridley 2016, and Kalpachidou et al. 2019). Classical RHO GTPases cycle between active GTP-bound states and inactive GDP-bound states through steps that are tightly controlled by members of three classes of proteins: (1) guanine nucleotide dissociation inhibitors or GDIs, which maintain Rho proteins in an inactive state in the cytoplasm, (2) guanine nucleotide exchange factors or GEFs, which destabilize the interaction between Rho proteins and their bound nucleotide, the net result of which is the exchange of bound GDP for the more abundant GTP, and (3) GTPase activating proteins or GAPs, which stimulate the low intrinsic GTP hydrolysis activity of Rho family members, thus promoting their inactivation. GDIs, GEFs, and GAPs are themselves subject to tight regulation, and the overall level of Rho activity reflects the balance of their activities. Many of the Rho-specific GEFs, GAPs, and GDIs act on multiple Rho GTPases, so that regulation of these control proteins can have complex effects on the functions of multiple Rho GTPases (reviewed by Van Aelst and D'Souza-Schorey 1997, Schmidt and Hall 2002, Jaffe and Hall 2005, Bernards 2005, and Hodge and Ridley 2016). Classical RHO GTPases include four subfamilies: Rho (includes RHOA, RHOB and RHOC), Rac (includes RAC1, RAC2, RAC3 and RHOG), Cdc42 (includes CDC42, RHOJ and RHOQ) and RhoD/RhoF (includes RHOD and RHOF) (reviewed in Haga and Ridley 2016). Atypical RHO GTPases do not possess GTPase activity. They therefore constitutively exist in the active GTP-bound state. Atypical RHO GTPases include three subfamilies: Rnd (includes RND1, RND2 and RND3), RhoBTB (includes RHOBTB1 and RHOBTB2), RhoH (RHOH is the only member) and RhoU/RhoV (includes RHOU and RHOV). Members of the Rho family have been identified in all eukaryotes. Among Rho GTPases, RHOA, RAC1 and CDC42 have been most extensively studied. RHO GTPases regulate cell behavior by activating a number of downstream effectors that regulate cytoskeletal organization, intracellular trafficking and transcription (reviewed by Sahai and Marshall 2002). They are best known for their ability to induce dynamic rearrangements of the plasma membrane-associated actin cytoskeleton (Aspenstrom et al. 2004; Murphy et al. 1999; Govek et al. 2005). Beyond this function, Rho GTPases also regulate actomyosin contractility and microtubule dynamics. Rho mediated effects on transcription and membrane trafficking are believed to be secondary to these functions. At the more macroscopic level, Rho GTPases have been implicated in many important cell biological processes, including cell growth control, cytokinesis, cell motility, cell-cell and cell-extracellular matrix adhesion, cell transformation and invasion, and development (Govek et al., 2005). One of the best studied RHO GTPase effectors are protein kinases ROCK1 and ROCK2, which phosphorylate many proteins involved in the stabilization of actin filaments and generation of actin-myosin contractile force, such as LIM kinases and myosin regulatory light chains (MRLC) (reviewed in Riento and Ridley 2003). The p21-activated kinase family, which includes PAK1, PAK2 and PAK3, is another well characterized family of RHO GTPase effectors involved in cytoskeleton regulation (reviewed in Daniels and Bokoch 1999, Szczepanowska 2009). Protein kinase C related kinases (PKNs), PKN1, PKN2 and PKN3 play important roles in cytoskeleton organization (Hamaguchi et al. 2000), regulation of cell cycle (Misaki et al. 2001), receptor trafficking (Metzger et al. 2003), apoptosis (Takahashi et al. 1998), and transcription (Metzger et al. 2003, Metzger et al. 2005, Metzger et al. 2008). Citron kinase (CIT) is involved in Golgi apparatus organization through regulation of the actin cytoskeleton (Camera et al. 2003) and in the regulation of cytokinesis (Gruneberg et al. 2006, Bassi et al. 2013, Watanabe et al. 2013). Kinectin (KTN1), a kinesin anchor protein, is a RHO GTPase effector involved in kinesin-mediated vesicle motility (Vignal et al. 2001, Hotta et al. 1996), including microtubule-dependent lysosomal transport (Vignal et al. 2001). IQGAP proteins, IQGAP1, IQGAP2 and IQGAP3, are RHO GTPase effectors that modulate cell shape and motility through regulation of G-actin/F-actin equilibrium (Brill et al. 1996, Fukata et al. 1997, Bashour et al. 1997, Wang et al. 2007, Pelikan-Conchaudron et al. 2011), regulate adherens junctions (Kuroda et al. 1998, Hage et al. 2009), and contribute to cell polarity and lamellipodia formation (Fukata et al. 2002, Suzuki and Takahashi 2008). WASP and WAVE proteins (reviewed by Lane et al. 2014), as well as formins (reviewed by Kuhn and Geyer 2014), are RHO GTPase effectors that regulate actin polymerization and play important roles in cell motility, organelle trafficking and mitosis. Rhotekin (RTKN) and rhophilins (RHPN1 and RHPN2) are RHO GTPase effectors that regulate the organization of the actin cytoskeleton and are implicated in the establishment of cell polarity, cell motility and possibly endosome trafficking (Sudo et al. 2006, Watanabe et al. 1996, Fujita et al. 2000, Peck et al. 2002, Mircescu et al. 2002). Cytoskeletal changes triggered by the activation of formins (Miralles et al. 2003) and RTKN (Reynaud et al. 2000) may lead to stimulation of SRF-mediated transcription. NADPH oxidase complexes 1, 2 and 3 (NOX1, NOX2 and NOX3), membrane associated enzymatic complexes that use NADPH as an electron donor to reduce oxygen and produce superoxide (O2-), are also regulated by RHO GTPases (Knaus et al. 1991, Roberts et al. 1999, Kim and Dinauer 2001, Jyoti et al. 2014, Cheng et al. 2006, Miyano et al. 2006, Ueyama et al. 2006). Every RHO GTPase activates multiple downstream effectors and most effectors are regulated by multiple RHO GTPases, resulting in an elaborate cross-talk."
BMGC_PW0767,BMG_PW3139,,,"The term non-coding is commonly employed for RNA that does not encode a protein, but this does not mean that such RNAs do not contain information nor have function. There is considerable evidence that the majority of mammalian and other complex organism's genomes is transcribed into non-coding RNAs, many of which are alternatively spliced and/or processed into smaller products. Around 98% of all transcriptional output in humans is non-coding RNA. RNA-mediated gene regulation is widespread in higher eukaryotes and complex genetic phenomena like RNA interference are mediated by such RNAs. These non-coding RNAs are a growing list and include rRNAs, tRNAs, snRNAs, snoRNAs siRNAs, 7SL RNA, 7SK RNA, the RNA component of RNase P RNA, the RNA component of RNase MRP, and the RNA component of telomerase."
BMGC_PW0768,BMG_PW3140,,,"The beta-catenin destruction complex plays a key role in the canonical Wnt signaling pathway. In the absence of Wnt signaling, this complex controls the levels of cytoplamic beta-catenin. Beta-catenin associates with and is phosphorylated by the destruction complex. Phosphorylated beta-catenin is recognized and ubiquitinated by the SCF-beta TrCP ubiquitin ligase complex and is subsequently degraded by the proteasome (reviewed in Kimelman and Xu, 2006)."
BMGC_PW0769,BMG_PW3141,,,"RHO GTPases regulate cell behaviour by activating a number of downstream effectors that regulate cytoskeletal organization, intracellular trafficking and transcription (reviewed by Sahai and Marshall 2002). One of the best studied RHO GTPase effectors are protein kinases ROCK1 and ROCK2, which are activated by binding RHOA, RHOB or RHOC. ROCK1 and ROCK2 phosphorylate many proteins involved in the stabilization of actin filaments and generation of actin-myosin contractile force, such as LIM kinases and myosin regulatory light chains (MRLC) (Amano et al. 1996, Ishizaki et al. 1996, Leung et al. 1996, Ohashi et al. 2000, Sumi et al. 2001, Riento and Ridley 2003, Watanabe et al. 2007). PAK1, PAK2 and PAK3, members of the p21-activated kinase family, are activated by binding to RHO GTPases RAC1 and CDC42 and subsequent autophosphorylation and are involved in cytoskeleton regulation (Manser et al. 1994, Manser et al. 1995, Zhang et al. 1998, Edwards et al. 1999, Lei et al. 2000, Parrini et al. 2002; reviewed by Daniels and Bokoch 1999, Szczepanowska 2009). RHOA, RHOB, RHOC and RAC1 activate protein kinase C related kinases (PKNs) PKN1, PKN2 and PKN3 (Maesaki et al. 1999, Zong et al. 1999, Owen et al. 2003, Modha et al. 2008, Hutchinson et al. 2011, Hutchinson et al. 2013), bringing them in proximity to the PIP3-activated PDPK1 (PDK1) and thus enabling PDPK1-mediated phosphorylation of PKN1, PKN2 and PKN3 (Flynn et al. 2000, Torbett et al. 2003). PKNs play important roles in cytoskeleton organization (Hamaguchi et al. 2000), regulation of cell cycle (Misaki et al. 2001), receptor trafficking (Metzger et al. 2003) and apoptosis (Takahashi et al. 1998). PKN1 is also involved in the ligand-dependent transcriptional activation by the androgen receptor (Metzger et al. 2003, Metzger et al. 2005, Metzger et al. 2008). Citron kinase (CIT) binds RHO GTPases RHOA, RHOB, RHOC and RAC1 (Madaule et al. 1995), but the mechanism of CIT activation by GTP-bound RHO GTPases has not been elucidated. CIT and RHOA are implicated to act together in Golgi apparatus organization through regulation of the actin cytoskeleton (Camera et al. 2003). CIT is also involved in the regulation of cytokinesis through its interaction with KIF14 (Gruneberg et al. 2006, Bassi et al. 2013, Watanabe et al. 2013). RHOA, RHOG, RAC1 and CDC42 bind kinectin (KTN1), a kinesin anchor protein involved in kinesin-mediated vesicle motility (Vignal et al. 2001, Hotta et al. 1996). The effect of RHOG activity on cellular morphology, exhibited in the formation of microtubule-dependent cellular protrusions, depends both on RHOG interaction with KTN1, as well as on the kinesin activity (Vignal et al. 2001). RHOG and KTN1 also cooperate in microtubule-dependent lysosomal transport (Vignal et al. 2001). IQGAP proteins IQGAP1, IQGAP2 and IQGAP3, bind RAC1 and CDC42 and stabilize them in their GTP-bound state (Kuroda et al. 1996, Swart-Mataraza et al. 2002, Wang et al. 2007). IQGAPs bind F-actin filaments and modulate cell shape and motility through regulation of G-actin/F-actin equilibrium (Brill et al. 1996, Fukata et al. 1997, Bashour et al. 1997, Wang et al. 2007, Pelikan-Conchaudron et al. 2011). Binding of IQGAPs to F-actin is inhibited by calmodulin (Bashour et al. 1997, Pelikan-Conchaudron et al. 2011). IQGAP1 is involved in the regulation of adherens junctions through its interaction with E-cadherin (CDH1) and catenins (CTTNB1 and CTTNA1) (Kuroda et al. 1998, Hage et al. 2009). IQGAP1 contributes to cell polarity and lamellipodia formation through its interaction with microtubules (Fukata et al. 2002, Suzuki and Takahashi 2008). RHOQ (TC10) regulates the trafficking of CFTR (cystic fibrosis transmembrane conductance regulator) by binding to the Golgi-associated protein GOPC (also known as PIST, FIG and CAL). In the absence of RHOQ, GOPC bound to CFTR directs CFTR for lysosomal degradation, while GTP-bound RHOQ directs GOPC:CFTR complex to the plasma membrane, thereby rescuing CFTR (Neudauer et al. 2001, Cheng et al. 2005). RAC1 and CDC42 activate WASP and WAVE proteins, members of the Wiskott-Aldrich Syndrome protein family. WASPs and WAVEs simultaneously interact with G-actin and the actin-related ARP2/3 complex, acting as nucleation promoting factors in actin polymerization (reviewed by Lane et al. 2014). RHOA, RHOB, RHOC, RAC1 and CDC42 activate a subset of formin family members. Once activated, formins bind G-actin and the actin-bound profilins and accelerate actin polymerization, while some formins also interact with microtubules. Formin-mediated cytoskeletal reorganization plays important roles in cell motility, organelle trafficking and mitosis (reviewed by Kuhn and Geyer 2014). Rhotekin (RTKN) and rhophilins (RHPN1 and RHPN2) are effectors of RHOA, RHOB and RHOC and have not been studied in detail. They regulate the organization of the actin cytoskeleton and are implicated in the establishment of cell polarity, cell motility and possibly endosome trafficking (Sudo et al. 2006, Watanabe et al. 1996, Fujita et al. 2000, Peck et al. 2002, Mircescu et al. 2002). Similar to formins (Miralles et al. 2003), cytoskeletal changes triggered by RTKN activation may lead to stimulation of SRF-mediated transcription (Reynaud et al. 2000). RHO GTPases RAC1 and RAC2 are needed for activation of NADPH oxidase complexes 1, 2 and 3 (NOX1, NOX2 and NOX3), membrane associated enzymatic complexes that use NADPH as an electron donor to reduce oxygen and produce superoxide (O2-). Superoxide serves as a secondary messenger and also directly contributes to the microbicidal activity of neutrophils (Knaus et al. 1991, Roberts et al. 1999, Kim and Dinauer 2001, Jyoti et al. 2014, Cheng et al. 2006, Miyano et al. 2006, Ueyama et al. 2006)."
BMGC_PW0770,BMG_PW3142,,,"The binding of VEGF ligands to VEGFR receptors in the cell membrane induces dimerization and activation of the latter, initiating intracellular signaling cascades that result in proliferation, survival, migration and increased permeability of vascular endothelial cells (Matsumoto and Mugishima, 2006). The receptors predominantly form homodimers but heterodimers between VEGFR-1 and -2 have been observed. Although both VEGFR-1 and -2 are expressed in the vascular endothelium, the angiogenic activities of VEGFs are transduced mainly through VEGFR-2 in vivo."
BMGC_PW0771,BMG_PW3143,,,"Gap junction plaque internalization and the disruption cell communication requires a reorganization of Cx molecular interactions. Proteins including Dab-2, AP-2, Dynamin and Myosin VI associate with gap junction plaques permitting the internalisation of plaques after clathrin association (Piehl et al., 2007). Until now, two kinds of annular gap junctions have been described. The first is a small vesicle like structure which permits gap junction plaque renewal without arrest of functionality (Jordan et al., 2001). The second is a large annular structure, composed primarily of the junctional plaques of two adjacent cells (Jordan et al., 2001; Segretain et al., 2004)."
BMGC_PW0772,BMG_PW3144,,,"The first process in the synthesis of all steroid hormones is the synthesis of pregnenolone from cholesterol. In this process, cholesterol mobilized from cytosolic lipid droplets or from lysosomes is transported to mitochondria and becomes localized to the inner mitochondrial membrane. Cholesterol transport appears to be rate-limiting for steroid hormone synthesis and its regulation, at the step of StAR-mediated traversal of the mitochondrial membrane, plays a central role in determining the amounts and identities of steroid hormones made in the body. In the inner mitochondrial membrane, cholesterol is converted to pregnenolone in a sequence of three reactions, all catalyzed by CYP11A (side chain cleavage enzyme). Finally, pregnenolone re-enters the cytosol (Payne and Hales 2004; Stocco 2001)."
BMGC_PW0773,BMG_PW3145,,,"Degradation of beta-catenin is initiated following amino-terminal serine/threonine phosphorylation. Phosphorylation of B-catenin at S45 by CK1 alpha primes the subsequent sequential GSK-3-mediated phosphorylation at Thr41, Ser37 and Ser33 (Amit et al., 2002 ; Lui et al., 2002)."
BMGC_PW0774,BMG_PW3146,,,"ERBB2:EGFR and ERBB2:ERBB4 can directly recruit GRB2:SOS1 complex through phosphorylated C-tail tyrosines of EGFR (Y1068 and Y1086) and ERBB2 (Y1139) that serve as docking sites for GRB2 (Xie et al. 1995, Sepp-Lorenzino et al. 1996), which, again, results in SOS1-mediated guanyl-nucleotide exchange on RAS and activation of RAF and MAP kinases (Janes et al. 1994, Sepp-Lorenzino et al. 1996)."
BMGC_PW0775,BMG_PW3147,,,"ERBB2:ERBB3 and ERBB2:ERBB4cyt1 heterodimers activate PI3K signaling by direct binding of PI3K regulatory subunit p85 (Yang et al. 2007, Cohen et al. 1996, Kaushansky et al. 2008) to phosphorylated tyrosine residues in the C-tail of ERBB3 (Y1054, Y1197, Y1222, Y1224, Y1276 and Y1289) and ERBB4 CYT1 isoforms (Y1056 in JM-A CYT1 isoform and Y1046 in JM-B CYT1 isoform). Regulatory subunit p85 subsequently recruits catalytic subunit p110 of PI3K, resulting in the formation of active PI3K, conversion of PIP2 to PIP3, and PIP3-mediated activation of AKT signaling (Junttila et al. 2009, Kainulainen et al. 2000). Heterodimers of ERBB2 and EGFR recruit PI3K indirectly, through GRB2:GAB1 complex (Jackson et al. 2004), which again leads to PIP3-mediated activation of AKT signaling."
BMGC_PW0776,BMG_PW3148,,,"Folates are essential cofactors that provide one-carbon moieties in various states of reduction for biosynthetic reactions. Processes annotated here include transport reactions by which folates are taken up by cells and moved intracellularly, folate conjugation with glutamate (required for folate retention within a cell), and some of the key reactions in the generation of reduced folates and one-carbon derivatives of folate."
BMGC_PW0777,BMG_PW3149,,,"Vitamin B1 (thiamin) is found naturally in certain foodstuffs such as green peas, spinach, liver, bananas, whole grains and legumes. Human diseases associated with thiamin deficiency include beriberi, due to a thiamin-deficient diet, TMRA, due to defects in the SLC19A2 transport protein, and Wernicke-Korsakoff Syndrome, associated with thiamin deficiency in alcoholism (Haas 1988). Thiamin is water-soluble so is not stored in the body. When pyrophosphorylated, thiamin is converted into the coenzyme thiamin pyrophosphate (ThPP, codecarboxylase) which plays an essential role in oxidative decarboxylation and group transfer reactions."
BMGC_PW0778,BMG_PW3150,,,"Vitamins are a diverse group of organic compounds, required in small amounts in the diet. They have distinct biochemical roles, often as coenzymes, and are either not synthesized or synthesized only in limited amounts by human cells. Vitamins are classified according to their solubility, either fat-soluble or water-soluble. The physiological processes dependent on vitamin-requiring reactions include many aspects of intermediary metabolism, vision, bone formation, and blood coagulation, and vitamin deficiencies are associated with a correspondingly diverse and severe group of diseases. Water-soluble vitamins include ascorbate (vitamin C) and the members of the B group: thiamin (vitamin B1), riboflavin (B2), niacin (B3), pantothenate (B5), pyridoxine (B6), biotin (B7), folate (B9), and cobalamin (B12). Metabolic processes annotated here include the synthesis of thiamin pyrophosphate (TPP) from thiamin (B1), the synthesis of FMN and FAD from riboflavin (B2), the synthesis of nicotinic acid (niacin - B3) from tryptophan, the synthesis of Coenzyme A from pantothenate (B5), features of the metabolism of folate (B9), the uptake, transport, and metabolism of cobalamin (B12), and molybdenum cofactor biosynthesis."
BMGC_PW0779,BMG_PW3151,,,"The biosynthesis of dermatan sulfate/chondroitin sulfate and heparin/heparan sulfate glycosaminoglycans (GAGs) starts with the formation of a tetrasaccharide linker sequence to the core protein. The first step is the addition of xylose to the hydroxy group of specific serine residues on the core protein. Subsequent additions of two galactoses and a glucuronide moiety completes the linker sequence. From here, the next hexosamine addition is critical as it determines which GAG is formed (Lamberg & Stoolmiller 1974, Pavao et al. 2006)."
BMGC_PW0780,BMG_PW3152,,,"NOTCH1 functions as both a transmembrane receptor presented on the cell surface and as a transcriptional regulator in the nucleus. NOTCH1 receptor presented on the plasma membrane is activated by a membrane bound ligand expressed in trans on the surface of a neighboring cell. In trans, ligand binding triggers proteolytic cleavage of NOTCH1 and results in release of the NOTCH1 intracellular domain, NICD1, into the cytosol. NICD1 translocates to the nucleus where it associates with RBPJ (also known as CSL or CBF) and mastermind-like (MAML) proteins (MAML1, MAML2 or MAML3; possibly also MAMLD1) to form NOTCH1 coactivator complex. NOTCH1 coactivator complex activates transcription of genes that possess RBPJ binding sites in their promoters."
BMGC_PW0781,BMG_PW3153,,,"NOTCH2 is activated by binding Delta-like and Jagged ligands (DLL/JAG) expressed in trans on neighboring cells (Shimizu et al. 1999, Shimizu et al. 2000, Hicks et al. 2000, Ji et al. 2004). In trans ligand-receptor binding is followed by ADAM10 mediated (Gibb et al. 2010, Shimizu et al. 2000) and gamma secretase complex mediated cleavage of NOTCH2 (Saxena et al. 2001, De Strooper et al. 1999), resulting in the release of the intracellular domain of NOTCH2, NICD2, into the cytosol. NICD2 traffics to the nucleus where it acts as a transcriptional regulator. For a recent review of the cannonical NOTCH signaling, please refer to Kopan and Ilagan 2009, D'Souza et al. 2010, Kovall and Blacklow 2010. CNTN1 (contactin 1), a protein involved in oligodendrocyte maturation (Hu et al. 2003) and MDK (midkine) (Huang et al. 2008, Gungor et al. 2011), which plays an important role in epithelial-to-mesenchymal transition, can also bind NOTCH2 and activate NOTCH2 signaling. In the nucleus, NICD2 forms a complex with RBPJ (CBF1, CSL) and MAML (mastermind). The NICD2:RBPJ:MAML complex activates transcription from RBPJ binding promoter elements (RBEs) (Wu et al. 2000). NOTCH2 coactivator complexes directly stimulate transcription of HES1 and HES5 genes (Shimizu et al. 2002), both of which are known NOTCH1 targets. NOTCH2 but not NOTCH1 coactivator complexes, stimulate FCER2 transcription. Overexpression of FCER2 (CD23A) is a hallmark of B-cell chronic lymphocytic leukemia (B-CLL) and correlates with the malfunction of apoptosis, which is thought be an underlying mechanism of B-CLL development (Hubmann et al. 2002). NOTCH2 coactivator complexes together with CREBP1 and EP300 stimulate transcription of GZMB (granzyme B), which is important for the cytotoxic function of CD8+ T cells (Maekawa et al. 2008). NOTCH2 gene expression is differentially regulated during human B-cell development, with NOTCH2 transcripts appearing at late developmental stages (Bertrand et al. 2000). NOTCH2 mutations are a rare cause of Alagille syndrome (AGS). AGS is a dominant congenital multisystem disorder characterized mainly by hepatic bile duct abnormalities. Craniofacial, heart and kidney abnormalities are also frequently observed in the Alagille spectrum (Alagille et al. 1975). AGS is predominantly caused by mutations in JAG1, a NOTCH2 ligand (Oda et al. 1997, Li et al. 1997), but it can also be caused by mutations in NOTCH2 (McDaniell et al. 2006). Hajdu-Cheney syndrome, an autosomal dominant disorder characterized by severe and progressive bone loss, is caused by NOTCH2 mutations that result in premature C-terminal NOTCH2 truncation, probably leading to increased NOTCH2 signaling (Simpson et al. 2011, Isidor et al. 2011, Majewski et al. 2011)."
BMGC_PW0782,BMG_PW3154,,"The phosphatidylinositol 3' -kinase(PI3K)-Akt signaling pathway is activated by many types of cellular stimuli or toxic insults and regulates fundamental cellular functions such as transcription, translation, proliferation, growth, and survival. The binding of growth factors to their receptor tyrosine kinase (RTK) or G protein-coupled receptors (GPCR) stimulates class Ia and Ib PI3K isoforms, respectively. PI3K catalyzes the production of phosphatidylinositol-3,4,5-triphosphate (PIP3) at the cell membrane. PIP3 in turn serves as a second messenger that helps to activate Akt. Once active, Akt can control key cellular processes by phosphorylating substrates involved in apoptosis, protein synthesis, metabolism, and cell cycle.","PI3K/AKT signalling is a major regulator of neuron survival. It blocks cell death by both impinging on the cytoplasmic cell death machinery and by regulating the expression of genes involved in cell death and survival. In addition, it may also use metabolic pathways to regulate cell survival.The PI3K/AKT pathway also affects axon diameter and branching (Marcus et al, 2002) and regulates small G proteins like RhoA (Vanhaesebroeck, B and Waterman, MD, 1999), which control the behaviour of the F-actin cytoskeleton. Moreover, through its connection with the TOR pathway, it promotes translation of a subset of mRNAs."
BMGC_PW0783,BMG_PW3155,,,"Following activation, AKT can phosphorylate an array of target proteins in the cytoplasm, many of which are involved in cell survival control. Phosphorylation of TSC2 feeds positively to the TOR kinase, which, in turn, contributes to AKT activation (positive feedback loop)."
BMGC_PW0784,BMG_PW3156,,,"After translocation into the nucleus, AKT can phosphorylate a number of targets there such as CREB, forkhead transcription factors, SRK and NUR77."
BMGC_PW0785,BMG_PW3157,,,"An important function of the kinase cascade triggered by neurotrophins is to induce the phosphorylation and activation of transcription factors in the nucleus to initiate new programs of gene expression. Transcription factors directly activated by neurotrophin signalling are responsible for induction of immediate-early genes, many of which are transcription factors. These in turn are involved in the induction of delayed-early genes."
BMGC_PW0786,BMG_PW3158,,,"Neurotrophin-induced increase in Signal transducer and activator of transcription 3 (STAT3; acute-phase response factor) activation appears to underly several downstream functions of neurotrophin signalling, such as transcription of immediate early genes, proliferation arrest, and neurite outgrowth."
BMGC_PW0787,BMG_PW3159,,,"ERK/MAPK kinases have a number of targets within the nucleus, usually transcription factors or other kinases. The best known targets, ELK1, ETS1, ATF2, MITF, MAPKAPK2, MSK1, RSK1/2/3 and MEF2 are annotated here."
BMGC_PW0788,BMG_PW3160,,,"A number of receptors and cell adhesion molecules play a key role in modifying the response of cells of lymphoid origin (such as B-, T- and NK cells) to self and tumor antigens, as well as to pathogenic organisms. Molecules such as KIRs and LILRs form part of a crucial surveillance system that looks out for any derangement, usually caused by cancer or viral infection, in MHC Class I presentation. Somatic cells are also able to report internal functional impairment by displaying surface stress markers such as MICA. The presence of these molecules on somatic cells is picked up by C-lectin NK immune receptors. Lymphoid cells are able to regulate their location and movement in accordance to their state of activation, and home in on tissues expressing the appropriate complementary ligands. For example, lymphoid cells may fine tune the presence and concentration of adhesion molecules belonging to the IgSF, Selectin and Integrin class that interact with a number of vascular markers of inflammation. Furthermore, there are a number of avenues through which lymphoid cells may interact with antigen. This may be presented directly to a specific T-cell receptor in the context of an MHC molecule. Antigen-antibody complexes may anchor to the cell via a small number of lymphoid-specific Fc receptors that may, in turn, influence cell function further. Activated complement factor C3d binds to both antigen and to cell surface receptor CD21. In such cases, the far-reaching influence of CD19 on B-lymphocyte function is tempered by its interaction with CD21."
BMGC_PW0789,BMG_PW3161,,,"The set of genes regulated by PPAR-alpha is not fully known in humans, however many examples have been found in mice. Genes directly activated by PPAR-alpha contain peroxisome proliferator receptor elements (PPREs) in their promoters and include: 1) genes involved in fatty acid oxidation and ketogenesis (Acox1, Cyp4a, Acadm, Hmgcs2); 2) genes involved in fatty acid transport (Cd36, , Slc27a1, Fabp1, Cpt1a, Cpt2); 3) genes involved in producing fatty acids and very low density lipoproteins (Me1, Scd1); 4) genes encoding apolipoproteins (Apoa1, Apoa2, Apoa5); 5) genes involved in triglyceride clearance ( Angptl4); 6) genes involved in glycerol metabolism (Gpd1 in mouse); 7) genes involved in glucose metabolism (Pdk4); 8) genes involved in peroxisome proliferation (Pex11a); 9) genes involved in lipid storage (Plin, Adfp). Many other genes are known to be regulated by PPAR-alpha but whether their regulation is direct or indirect remains to be found. These genes include: ACACA, FAS, SREBP1, FADS1, DGAT1, ABCA1, PLTP, ABCB4, UGT2B4, SULT2A1, Pnpla2, Acsl1, Slc27a4, many Acot genes, and others (reviewed in Rakhshandehroo et al. 2010)."
BMGC_PW0790,BMG_PW3162,,,"The PI3K/AKT network is negatively regulated by phosphatases that dephosphorylate PIP3, thus hampering AKT activation."
BMGC_PW0791,BMG_PW3163,,,"Nerve growth factor (NGF) activates multiple signalling pathways that mediate the phosphorylation of CREB at the critical regulatory site, serine 133. CREB phosphorylation at serine 133 is a crucial event in neurotrophin signalling, being mediated by ERK/RSK, ERK/MSK1 and p38/MAPKAPK2 pathways. Several kinases, such as MSK1, RSK1/2/3 (MAPKAPK1A/B/C), and MAPKAPK2, are able to directly phosphorylate CREB at S133. MSK1 is also able to activate ATF (Cyclic-AMP-dependent transcription factor). However, the NGF-induced CREB phosphorylation appears to correlate better with activation of MSK1 rather than RSK1/2/3, or MAPKAPK2. In retrograde signalling, activation of CREB occurs within 20 minutes after neurotrophin stimulation of distal axons."
BMGC_PW0792,BMG_PW3164,,,"Secretory cargo destined to be secreted or to arrive at the plasma membrane (PM) leaves the ER via distinct exit sites. This cargo is destined for the Golgi apparatus for further processing. About 25% of the proteome may be exported from the ER in human cells. This cargo is recognized and concentrated into COPII vesicles, which range in size from 60-90 nm, and move cargo from the ER to the ERGIC. Soluble cargo in the ER lumen is concentrated into COPII vesicles through interaction with a receptor with the receptor subsequently recycled to the ER in COPI vesicles through retrograde traffic. The ERGIC (ER-to-Golgi intermediate compartment, also known as vesicular-tubular clusters, VTCs) is a stable, biochemically distinct compartment located adjacent to ER exit sites. Retrograde traffic makes use of microtubule-directed COPI-coated vesicles, carrying ER proteins and membrane back to the ER."
BMGC_PW0793,BMG_PW3165,,,"The secretory membrane system allows a cell to regulate delivery of newly synthesized proteins, carbohydrates, and lipids to the cell surface, a necessity for growth and homeostasis. The system is made up of distinct organelles, including the endoplasmic reticulum (ER), Golgi complex, plasma membrane, and tubulovesicular transport intermediates. These organelles mediate intracellular membrane transport between themselves and the cell surface. Membrane traffic within this system flows along highly organized directional routes. Secretory cargo is synthesized and assembled in the ER and then transported to the Golgi complex for further processing and maturation. Upon arrival at the trans Golgi network (TGN), the cargo is sorted and packaged into post-Golgi carriers that move through the cytoplasm to fuse with the cell surface. This directional membrane flow is balanced by retrieval pathways that bring membrane and selected proteins back to the compartment of origin."
BMGC_PW0794,BMG_PW3166,,,"After passing through the Golgi complex, secretory cargo is packaged into post-Golgi transport intermediates (post-Golgi), which translocate plus-end directed along microtubules to the plasma membrane. There at least two classes of clathrin coated vesicles in cells, one predominantly Golgi-associated, involved in budding from the trans-Golgi network and the other at the plasma membrane. Here the clathrin-coated vesicles emerging from the Golgi apparatus are triggered by the heterotetrameric adaptor protein complex, AP-1 at the trans-Golgi network membrane. The cargo can be transmembrane, membrane associated or golgi luminal proteins. Each step in the vesicle sculpting pathway, gathers cargo and clathrin triskeletons, until a complete vesicular sphere is formed. With the scission of the membrane the vesicle is released and eventually losses its clathrin coat."
BMGC_PW0795,BMG_PW3168,,,"19 WNT ligands and 10 FZD receptors have been identified in human cells; interactions amongst these ligands and receptors vary in a developmental and tissue-specific manner and lead to activation of so-called 'canonical' and 'non-canonical' WNT signaling. In the canonical WNT signaling pathway, binding of a WNT ligand to the Frizzled (FZD) and lipoprotein receptor-related protein (LRP) receptors results in the inactivation of the destruction complex, the stabilization and nuclear translocation of beta-catenin and subsequent activation of T-cell factor/lymphoid enhancing factor (TCF/LEF)-dependent transcription. Transcriptional activation in response to canonical WNT signaling controls processes such as cell fate, proliferation and self renewal of stem cells, as well as contributing to oncogenesis (reviewed in MacDonald et al, 2009; Saito-Diaz et al, 2013; Kim et al, 2013)."
BMGC_PW0796,BMG_PW3169,,,"The three human Dishevelled (DVL) proteins play a central and overlapping role in the transduction of the WNT signaling cascade (Lee et al, 2008; reviewed in Gao and Chen 2010). DVL activity is regulated by phosphorylation, although the details are not completely worked out. DVL likely exists as a phosphoprotein even in the absence of WNT stimulation, and is further phosphorylated upon ligand binding. Casein kinase 1epsilon (CSNK1E), casein kinase 2 (CSNK2) and PAR1 have all been reported to phosphorylate DVL (Willert et al, 1997; Sun et al, 2001; Cong et al, 2004; Ossipova et al, 2005). Upon pathway activation, phosphorylated DVL translocates to the plasma membrane through an interaction between the DVL PDZ domain and the FZD KTxxxW motif (Wong et al, 2003; Umbhauer et al, 2000; Kikuchi et al, 2011). At the plasma membrane, DVL is believed to oligomerize through its DIX domain, providing a platform for AXIN recruitment; recruitment of AXIN is also facilitated by interaction with LRP (Schwarz-Romond et al, 2007; Mao et al, 2001). DVL interacts with phosphatidylinositol-4-kinase type II (PI4KII) and phophatidylinositol-4-phosphate 5-kinase type I (PIP5KI) to promote formation of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) in the membrane, which is required for the clustering and phosphorylation of LRP6 and the recruitment of AXIN (Pan et al, 2008; Qin et al, 2009)."
BMGC_PW0797,BMG_PW3170,,,"Once in the nucleus, beta-catenin is recruited to WNT target genes through interaction with TCF/LEF transcription factors. This family, which consists of TCF7 (also known as TCF1), TCF7L1 (also known as TCF3), TCF7L2 (also known as TCF4) and TCF7L3 (also known as LEF1), are HMG-containing transcription factors that bind to the WNT responsive elements in target gene promoters (reviewed in Brantjes et al, 2002). In the absence of WNT signal, TCF/LEF proteins recruit Groucho/TLE repressors to inhibit transcription; upon WNT stimulation, beta-catenin can displace Groucho/TLE from TCF/LEF proteins to initiate transcriptional activation (reviewed in Chen and Courey, 2000). Although this model for WNT-dependent activation of target genes is widely accepted, it is important to note that TCF/LEF proteins are not redundant and can contribute to WNT target gene expression in a number of different ways (reviewed in Brantjes et al, 2002; MacDonald et al, 2009). In particular, TCF7L1 (TCF3) is thought to have a more pronounced repressor function than other TCF/LEF family members. A couple of recent studies in Xenopus and mammalian cells show that WNT- and beta-catenin-dependent phosphorylation of TCF7L1(TCF3) promotes its dissociation from the promoter of target genes and allows gene expression through relief of this repression activity (Hikasa et al, 2010; Hikasa et al, 2011). The role of beta-catenin at WNT promoters hinges upon its ability to act as a scaffold for the recruitment of other proteins. The structure of beta-catenin consists of 12 imperfect ARM repeats (R1-12) flanked by an N-terminal and C-terminal extension (NTD and CTD respectively), with a conserved Helix C located between R12 and the CTD. Nuclear beta-catenin interacts with TCF/LEF at WNT target genes through ARM domains 3-9 (Graham et al, 2000; Poy et al, 2001; Xing et al, 2008). The N and the C terminal regions are important for the recruitment of transcriptional activator and repressors that contribute to WNT target gene expression (reviewed in Mosimann et al, 2009; Valenta et al, 2012). The N-terminal ARM domains 1-4 recruit the WNT-pathway specific activators BCL9:PYGO while the C-terminal region (R11-CTD) interacts with a wide range of general transcriptional activators that are involved in chromatin remodelling and transcription initiation. These include HATs such as P300, CBP and TIP60, histone methyltransferases such as MLL1 and 2, SWI/SNF factors BRG1 and ISWI and components of the PAF complex (reviewed in Mosimann et al, 2009; Valenta et al, 2012). Although many binding partners have been identified for the C-terminal region of beta-catenin, in many cases the timing and relationship of these interactions and indeed, the exact complex composition remains to be elucidated. Moreover, because many of the interacting partners appear to bind to overlapping regions of beta-catenin, it is unlikely that they all bind simultaneously. For simplicity, the interactions have been depicted as though they occur independently of one another; more accurately they are likely to cycle successively on and off beta-catenin to promote an active chromatin structure (reviewed in Willert and Jones, 2006; Valenta et al, 2012)."
BMGC_PW0798,BMG_PW3171,,,"Receptor activated heterotrimeric G proteins consist of the Galpha and the tightly associated Gbeta-gamma subunits. When a ligand binds to a G protein-coupled receptor, it stabilises a conformation with an high affinity for the G-protein bound to GDP. GDP is then exchanged for GTP on the Galpha subunit. This exchange triggers the dissociation of the Galpha subunit from the Gbeta-gamma dimer and the receptor. Galpha-GTP and Gbeta-gamma, can then modulate different signalling cascades and effector proteins, while the receptor is able to activate another G protein, resulting in an amplification cascade. The Galpha subunit will eventually hydrolyze the attached GTP to GDP by its inherent enzymatic activity, allowing it to reassociate with Gbeta-gamma and start a new cycle."
BMGC_PW0799,BMG_PW3172,,,"Nitric oxide (NO), a multifunctional second messenger, is implicated in physiological processes in mammals that range from immune response and potentiation of synaptic transmission to dilation of blood vessels and muscle relaxation. NO is a highly active molecule that diffuses across cell membranes and cannot be stored inside the producing cell. Its signaling capacity is controlled at the levels of biosynthesis and local availability. Its production by NO synthases is under complex and tight control, being regulated at transcriptional and translational levels, through co- and posttranslational modifications, and by subcellular localization. NO is synthesized from L-arginine by a family of nitric oxide synthases (NOS). Three NOS isoforms have been characterized: neuronal NOS (nNOS, NOS1) primarily found in neuronal tissue and skeletal muscle; inducible NOS (iNOS, NOS2) originally isolated from macrophages and later discovered in many other cell types; and endothelial NOS (eNOS, NOS3) present in vascular endothelial cells, cardiac myocytes, and in blood platelets. The enzymatic activity of all three isoforms is dependent on calmodulin, which binds to nNOS and eNOS at elevated intracellular calcium levels, while it is tightly associated with iNOS even at basal calcium levels. As a result, the enzymatic activity of nNOS and eNOS is modulated by changes in intracellular calcium levels, leading to transient NO production, while iNOS continuously releases NO independent of fluctuations in intracellular calcium levels and is mainly regulated at the gene expression level (Pacher et al. 2007). The NOS enzymes share a common basic structural organization and requirement for substrate cofactors for enzymatic activity. A central calmodulin-binding motif separates an NH2-terminal oxygenase domain from a COOH-terminal reductase domain. Binding sites for cofactors NADPH, FAD, and FMN are located within the reductase domain, while binding sites for tetrahydrobiopterin (BH4) and heme are located within the oxygenase domain. Once calmodulin binds, it facilitates electron transfer from the cofactors in the reductase domain to heme enabling nitric oxide production. Both nNOS and eNOS contain an additional insert (40-50 amino acids) in the middle of the FMN-binding subdomain that serves as autoinhibitory loop, destabilizing calmodulin binding at low calcium levels and inhibiting electron transfer from FMN to the heme in the absence of calmodulin. iNOS does not contain this insert. In this Reactome pathway module, details of eNOS activation and regulation are annotated. Originally identified as endothelium-derived relaxing factor, eNOS derived NO is a critical signaling molecule in vascular homeostasis. It regulates blood pressure and vascular tone, and is involved in vascular smooth muscle cell proliferation, platelet aggregation, and leukocyte adhesion. Loss of endothelium derived NO is a key feature of endothelial dysfunction, implicated in the pathogenesis of hypertension and atherosclerosis. The endothelial isoform eNOS is unique among the nitric oxide synthase (NOS) family in that it is co-translationally modified at its amino terminus by myristoylation and is further acylated by palmitoylation (two residues next to the myristoylation site). These modifications target eNOS to the plasma membrane caveolae and lipid rafts. Factors that stimulate eNOS activation and nitric oxide (NO) production include fluid shear stress generated by blood flow, vascular endothelial growth factor (VEGF), bradykinin, estrogen, insulin, and angiopoietin. The activity of eNOS is further regulated by numerous post-translational modifications, including protein-protein interactions, phosphorylation, and subcellular localization. Following activation, eNOS shuttles between caveolae and other subcellular compartments such as the noncaveolar plasma membrane portions, Golgi apparatus, and perinuclear structures. This subcellular distribution is variable depending upon cell type and mode of activation. Subcellular localization of eNOS has a profound effect on its ability to produce NO as the availability of its substrates and cofactors will vary with location. eNOS is primarily particulate, and depending on the cell type, eNOS can be found in several membrane compartments: plasma membrane caveolae, lipid rafts, and intracellular membranes such as the Golgi complex."
BMGC_PW0800,BMG_PW3173,,,"Collagen trimers in triple-helical form, referred to as procollagen or collagen molecules, are exported from the ER and trafficked through the Golgi network before secretion into the extracellular space. For fibrillar collagens namely types I, II, III, V, XI, XXIV and XXVII (Gordon & Hahn 2010, Ricard-Blum 2011) secretion is concomitant with processing of the N and C terminal collagen propeptides. These processed molecules are known as tropocollagens, considered to be the units of higher order collagen structures. They form within the extracellular space via a process that can proceed spontaneously, but in the cellular environment is regulated by many collagen binding proteins such as the FACIT (Fibril Associated Collagens with Interrupted Triple helices) family collagens and Small Leucine-Rich Proteoglycans (SLRPs). The architecture formed ultimately depends on the collagen subtype and the cellular conditions. Structures include the well-known fibrils and fibres formed by the major structural collagens type I and II plus several different types of supramolecular assembly (Bruckner 2010). The mechanical and physical properties of tissues depend on the spatial arrangement and composition of these collagen-containing structures (Kadler et al. 1996, Shoulders & Raines 2009, Birk & Bruckner 2011). Fibrillar collagen structures are frequently heterotypic, composed of a major collagen type in association with smaller amounts of other types, e.g. type I collagen fibrils are associated with types III and V, while type II fibrils frequently contain types IX and XI (Wess 2005). Fibres composed exclusively of a single collagen type probably do not exist, as type I and II fibrils require collagens V and XI respectively as nucleators (Kadler et al. 2008, Wenstrup et al. 2011). Much of the structural understanding of collagen fibrils has been obtained with fibril-forming collagens, particularly type I, but some central features are believed to apply to at least the other fibrillar collagen subtypes (Wess 2005). Fibril diameter and length varies considerably, depending on the tissue and collagen types (Fang et al. 2012). The reasons for this are poorly understood (Wess 2005). Some tissues such as skin have fibres that are approximately the same diameter while others such as tendon or cartilage have a bimodal distribution of thick and thin fibrils. Mature type I collagen fibrils in tendon are up to 1 cm in length, with a diameter of approx. 500 nm. An individual fibrillar collagen triple helix is less than 1.5 nm in diameter and around 300 nm long; collagen molecules must assemble to give rise to the higher-order fibril structure, a process known as fibrillogenesis, prevented by the presence of C-terminal propeptides (Kadler et al. 1987). In electron micrographs, fibrils have a banded appearance, due to regular gaps where fewer collagen molecules overlap, which occur because the fibrils are aligned in a quarter-stagger arrangement (Hodge & Petruska 1963). Collagen microfibrils are believed to have a quasi-hexagonal unit cell, with tropocollagen arranged to form supertwisted, right-handed microfibrils that interdigitate with neighbouring microfibrils, leading to a spiral-like structure for the mature collagen fibril (Orgel et al. 2006, Holmes & Kadler 2006). Neighbouring tropocollagen monomers interact with each other and are cross-linked covalently by lysyl oxidase (Orgel et al. 2000, Maki 2006). Mature collagen fibrils are stabilized by lysyl oxidase-mediated cross-links. Hydroxylysyl pyridinoline and lysyl pyridinoline cross-links form between (hydroxy) lysine and hydroxylysine residues in bone and cartilage (Eyre et al. 1984). Arginoline cross-links can form in cartilage (Eyre et al. 2010); mature bovine articular cartilage contains roughly equimolar amounts of arginoline and hydroxylysyl pyridinoline based on peptide yields. Mature collagen fibrils in skin are stabilized by the lysyl oxidase-mediated cross-link histidinohydroxylysinonorleucine (Yamauch et al. 1987). Due to the quarter-staggered arrangement of collagen molecules in a fibril, telopeptides most often interact with the triple helix of a neighbouring collagen molecule in the fibril, except for collagen molecules in register staggered by 4D from another collagen molecule. Fibril aggregation in vitro can be unipolar or bipolar, influenced by temperature and levels of C-proteinase, suggesting a role for the N- and C- propeptides in regulation of the aggregation process (Kadler et al. 1996). In vivo, collagen molecules at the fibril surface may retain their N-propeptides, suggesting that this may limit further accretion, or alternatively represents a transient stage in a model whereby fibrils grow in diameter through a cycle of deposition, cleavage and further deposition (Chapman 1989). In vivo, fibrils are often composed from more than one type of collagen. Type III collagen is found associated with type I collagen in dermal fibrils, with the collagen III on the periphery, suggesting a regulatory role (Fleischmajer et al. 1990). Type V collagen associates with type I collagen fibrils, where it may limit fibril diameter (Birk et al. 1990, White et al. 1997). Type IX associates with the surface of narrow diameter collagen II fibrils in cartilage and the cornea (Wu et al. 1992, Eyre et al. 2004). Highly specific patterns of crosslinking sites suggest that collagen IX functions in interfibrillar networking (Wess 2005). Type XII and XIV collagens are localized near the surface of banded collagen I fibrils (Nishiyama et al. 1994). Certain fibril-associated collagens with interrupted triple helices (FACITs) associate with the surface of collagen fibrils, where they may serve to limit fibril fusion and thereby regulate fibril diameter (Gordon & Hahn 2010). Collagen XV, a member of the multiplexin family, is almost exclusively associated with the fibrillar collagen network, in very close proximity to the basement membrane. In human tissues collagen XV is seen linking banded collagen fibers subjacent to the basement membrane (Amenta et al. 2005). Type XIV collagen, SLRPs and discoidin domain receptors also regulate fibrillogenesis (Ansorge et al. 2009, Kalamajski et al. 2010, Flynn et al. 2010). Collagen IX is cross-linked to the surface of collagen type II fibrils (Eyre et al. 1987). Type XII and XIV collagens are found in association with type I (Walchli et al. 1994) and type II (Watt et al. 1992, Eyre 2002) fibrils in cartilage. They are thought to associate non-covalently via their COL1/NC1 domains (Watt et al. 1992, Eyre 2002). Some non-fibrillar collagens form supramolecular assemblies that are distinct from typical fibrils. Collagen VII forms anchoring fibrils, composed of antiparallel dimers that connect the dermis to the epidermis (Bruckner-Tuderman 2009). During fibrillogenesis, the nascent type VII procollagen molecules dimerize in an antiparallel manner. The C-propeptides are then removed by Bone morphogenetic protein 1 (Rattenholl et al. 2002) and the processed antiparallel dimers aggregate laterally. Collagens VIII and X form hexagonal networks and collagen VI forms beaded filament (Gordon & Hahn 2010, Ricard-Blum et al. 2011)."
BMGC_PW0801,BMG_PW3174,,,"Angiotensinogen, a prohormone, is synthesized and secreted mainly by the liver but also from other tissues (reviewed in Fyhrquist and Saijonmaa 2008, Cat and Touyz 2011). Renin, an aspartyl protease specific for angiotensinogen, is secreted into the bloodstream by juxtaglomerular cells of the kidney in response to a drop in blood pressure. Renin cleaves angiotensinogen to yield a decapaptide, angiotensin I (angiotensin-1, angiotensin-(1-10)). Circulating renin can also bind the membrane-localized (pro)renin receptor (ATP6AP2) which increases its catalytic activity. After cleavage of angiotensinogen to angiotensin I by renin, two C-terminal amino acid residues of angiotensin I are removed by angiotensin-converting enzyme (ACE), located on the surface of endothelial cells, to yield angiotensin II (angiotensin-2, angiotensin-(1-8)), the active peptide that causes vasoconstriction, resorption of sodium and chloride, excretion of potassium, water retention, and aldosterone secretion. More recently other, more tissue-localized pathways leading to angiotensin II and alternative derivatives of angiotensinogen have been identified (reviewed in Kramkowski et al. 2006, Kumar et al. 2007, Fyhrquist and Saijonmaa 2008, Becari et al. 2011). Chymase, cathepsin G, and cathepsin X (cathepsin Z) can each cleave angiotensin I to yield angiotensin II. Angiotensin-converting enzyme 2 (ACE2) cleaves 1 amino acid residue from angiotensin I (angiotensin-(1-10)) to yield angiotensin-(1-9), which can be cleaved by ACE to yield angiotensin-(1-7). ACE2 can also cleave angiotensin II to yield angiotensin-(1-7). Neprilysin can cleave either angiotensin-(1-9) or angiotensin I to yield angiotensin-(1-7). Angiotensin-(1-7) binds the MAS receptor (MAS1, MAS proto-oncogene) and, interestingly, produces effects opposite to those produced by angiotensin II. Aminopeptidase A (APA, ENPEP) cleaves angiotensin II to yield angiotensin III (angiotensin-(2-8)), which is then cleaved by aminopeptidase N (APN, ANPEP) yielding angiotensin IV (angiotensin-(3-8)). Angiotensin IV binds the AT4 receptor (AT4R, IRAP, LNPEP, oxytocinase). Inhibitors of renin (e.g. aliskiren) and ACE (e.g. lisinopril, ramipril) are currently used to treat hypertension (reviewed in Gerc et al. 2009, Verdecchia et al. 2010, Alreja and Joseph 2011)."
BMGC_PW0802,BMG_PW3175,,,"Keratan sulfate proteoglycans (KSPGs) are degraded in lysosomes as part of normal homeostasis of glycoproteins. Glycoproteins must be completely degraded to avoid undigested fragments building up and causing a variety of lysosomal storage diseases. KSPGs are Asn-linked glycoproteins and are acted upon by exo-glycosidases to release sugar monomers. The main steps of degradation are shown representing the types of cleavage reactions that occur so the full degradation of KS is not shown to avoid repetition. The proteolysis of the core protein of the glycoprotein is not shown here (Winchester 2005, Aronson & Kuranda 1989)."
BMGC_PW0803,BMG_PW3177,,,Lysosomal degradation of glycoproteins is part of the cellular homeostasis of glycosylation (Winchester 2005). The steps outlined below describe the degradation of heparan sulfate/heparin. Complete degradation of glycoproteins is required to avoid build up of glycosaminoglycan fragments which can cause lysosomal storage diseases. The proteolysis of the core protein of the glycoprotein is not shown here.
BMGC_PW0804,BMG_PW3178,,,Lysosomal degradation of glycoproteins is part of the cellular homeostasis of glycosylation (Winchester 2005). The steps outlined below describe the degradation of chondroitin sulfate and dermatan sulfate. Complete degradation of glycoproteins is required to avoid build up of glycosaminoglycan fragments which can cause lysosomal storage diseases. Complete degradation steps are not shown as they are repetitions of the main ones described here. The proteolysis of the core protein of the glycoprotein is not shown here.
BMGC_PW0805,BMG_PW3179,,,"Changes in gene expression are required for the T cell to gain full proliferative competence and to produce effector cytokines. Three transcription factors in particular have been found to play a key role in TCR-stimulated changes in gene expression, namely NFkappaB, NFAT and AP-1. A key step in NFkappaB activation is the stimulation and translocation of PRKCQ. The critical element that effects PRKCQ activation is PI3K. PI3K translocates to the plasma membrane by interacting with phospho-tyrosines on CD28 via its two SH2 domains located in p85 subunit (step 24). The p110 subunit of PI3K phosphorylates the inositol ring of PIP2 to generate PIP3 (steps 25). The reverse dephosphorylation process from PIP3 to PIP2 is catalysed by PTEN (step 27). PIP3 may also be dephosphorylated by the phosphatase SHIP to generate PI-3,4-P2 (step 26). PIP3 and PI-3,4-P2 acts as binding sites to the PH domain of PDK1 (step 28) and AKT (step 29). PKB is activated in response to PI3K stimulation by PDK1 (step 30). PDK1 has an essential role in regulating the activation of PRKCQ and recruitment of CBM complex to the immune synapse. PRKCQ is a member of novel class (DAG dependent, Ca++ independent) of PKC and the only member known to translocate to this synapse. Prior to TCR stimulation PRKCQ exists in an inactive closed conformation. TCR signals stimulate PRKCQ (step 31) and release DAG molecules. Subsequently, DAG binds to PRKCQ via the C1 domain and undergoes phosphorylation on tyrosine 90 by LCK to attain an open conformation (step 32). PRKCQ is further phosphorylated by PDK1 on threonine 538 (step 33). This step is critical for PKC activity. CARMA1 translocates to the plasma membrane following the interaction of its SH3 domain with the 'PxxP' motif on PDK1 (step 34). CARMA1 is phosphorylated by PKC-theta on residue S552 (step 35), leading to the oligomerization of CARMA1. This complex acts as a scaffold, recruiting BCL10 to the synapse by interacting with their CARD domains (step 36). BCL10 undergoes phosphorylation mediated by the enzyme RIP2 (step 37). Activated BCL10 then mediates the ubiquitination of IKBKG by recruiting MALT1 and TRAF6. MALT1 binds to BCL10 with its Ig-like domains and undergoes oligomerization (step 38). TRAF6 binds to the oligomerized MALT1 and also undergoes oligomerization (step 39). Oligomerized TRAF6 acts as a ubiquitin-protein ligase, catalyzing auto-K63-linked polyubiquitination (step 40). This K-63 ubiquitinated TRAF6 activates MAP3K7 kinase bound to TAB2 (step 41) and also ubiquitinates IKBKG in the IKK complex (step 44). MAP3K7 undergoes autophosphorylation on residues T184 and T187 and gets activated (step 42). Activated MAP3K7 kinase phosphorylates IKBKB on residues S177 and S181 in the activation loop and activates the IKK kinase activity (step 43). IKBKB phosphorylates the NFKBIA bound to the NFkappaB heterodimer, on residues S19 and S23 (step 45) and directs NFKBIA to 26S proteasome degradation (step 47). The NFkappaB heterodimer with a free NTS sequence finally migrates to the nucleus to regulate gene transcription (step 46)."
BMGC_PW0806,BMG_PW3180,,,"Prior to T cell receptor (TCR) stimulation, CD4/CD8 associated LCK remains seperated from the TCR and is maintained in an inactive state by the action of CSK. PAG bound CSK phosphorylates the negative regulatory tyrosine of LCK and inactivates the LCK kinase domain (step 1). CSK also inhibits PTPN22 by sequestering it via binding (step 2). Upon TCR stimulation, CSK dissociates from PAG1 (step 3) and PTPN22 (step4) and is unable to inhibit LCK. Furthermore, LCK becomes activated via PTPRC-mediated dephosphorylation of negative regulatory tyrosine residues (step 5). CD4/CD8 binds MHCII receptor in APC and the associated LCK co-localizes with the TCR. LCK is further activated by trans-autophosphorylation on the tyrosine residue on its activation loop (step 6). Active LCK further phosphorylates the tyrosine residues on CD3 chains. The signal-transducing CD3 delta/epsilon/gamma and TCR zeta chains contain a critical signaling motif known as the immunoreceptor tyrosine-based activation motif (ITAM). The two critical tyrosines of each ITAM motif are phosphorylated by LCK (step 7)."
BMGC_PW0807,BMG_PW3181,,,The dual phosphorylated ITAMs recruit SYK kinase ZAP70 via their tandem SH2 domains (step 8). ZAP70 subsequently undergoes phosphorylation on multiple tyrosine residues for further activation. ZAP70 includes both positive and negative regulatory sites. Tyrosine 493 is a conserved regulatory site found within the activation loop of the kinase domain. This site has shown to be a positive regulatory site required for ZAP70 kinase activity and is phosphorylated by LCK (step 9). This phosphorylation contributes to the active conformation of the catalytic domain. Later ZAP70 undergoes trans-autophosphorylation at Y315 and Y319 (step 10). These sites appear to be positive regulatory sites. ZAP70 achieves its full activation after the trans-autophosphorylation. Activated ZAP70 along with LCK phosphorylates the multiple tyrosine residues in the adaptor protein LAT (step 11). PTPN22 can dephosphorylate and inhibit ZAP70 activity to downregulate TCR signaling (step 12).
BMGC_PW0808,BMG_PW3182,,,"In addition to serving as a scaffold via auto-phosphorylation, ZAP70 also phosphorylates a restricted set of substrates following TCR stimulation - including LAT (step 13) and LCP2. These substrates have been recognized to play pivotal role in TCR signaling by releasing second messengers. When phosphorylated, LAT and SLP-76 act as adaptor proteins which serve as nucleation points for the construction of a higher order signalosome: PLC-gamma1 (step 14) and GRAP2 (step 15) bind to the LAT on the phosphorylated tyrosine residues. LCP2 is then moved to the signalosome by interacting with the SH3 domains of GRAP2 using their proline rich sequences (step 16). Once LCP2 binds to GRAP2, three LCP2 acidic domain N-term tyrosine residues are phosphorylated by ZAP70 (step 17). These phospho-tyrosine residues act as binding sites to the SH2 domains of ITK (steps 18) and PLC-gamma1 (step 19). PLC-gamma1 is activated by dual phosphorylation on the tyrosine residues at positions 771, 783 and 1254 by ITK (step 20) and ZAP70 (step 21). Phosphorylated PLC-gamma1 subsequently detaches from LAT and LCP2 and translocates to the plasma membrane by binding to phosphatidylinositol-4,5-bisphosphate (PIP2) via its PH domain (step 22). PLC-gamma1 goes on to hydrolyse PIP2 to second messengers DAG and IP3 (step 23). These second messengers are involved in PKC and NF-kB activation and calcium mobilization."
BMGC_PW0809,BMG_PW3183,,,"MAP Kinases are inactivated by a family of protein named MAP Kinase Phosphatases (MKPs). They act through dephosphorylation of threonine and/or tyrosine residues within the signature sequence -pTXpY- located in the activation loop of MAP kinases (pT=phosphothreonine and pY=phosphotyrosine). MKPs are divided into three major categories depending on their preference for dephosphorylating; tyrosine, serine/threonine and both the tyrosine and threonine (dual specificity phoshatases or DUSPs). The tyrosine-specific MKPs include PTP-SL, STEP and HePTP, serine/threonine-specific MKPs are PP2A and PP2C, and many DUSPs acting on MAPKs are known. Activated MAP kinases trigger activation of transcription of MKP genes. Therefore, MKPs provide a negative feedback regulatory mechanism on MAPK signaling, by inactivating MAPKs via dephosphorylation, in the cytoplasm and the nucleus. Some MKPs are more specific for ERKs, others for JNK or p38MAPK."
BMGC_PW0810,BMG_PW3184,,,"Leukocyte extravasation is a rigorously controlled process that guides white cell movement from the vascular lumen to sites of tissue inflammation. The powerful adhesive interactions that are required for leukocytes to withstand local flow at the vessel wall is a multistep process mediated by different adhesion molecules. Platelets adhered to injured vessel walls form strong adhesive substrates for leukocytes. For instance, the initial tethering and rolling of leukocytes over the site of injury are mediated by reversible binding of selectins to their cognate cell-surface glycoconjugates. Endothelial cells are tightly connected through various proteins, which regulate the organization of the junctional complex and bind to cytoskeletal proteins or cytoplasmic interaction partners that allow the transfer of intracellular signals. An important role for these junctional proteins in governing the transendothelial migration of leukocytes under normal or inflammatory conditions has been established. This pathway describes some of the key interactions that assist in the process of platelet and leukocyte interaction with the endothelium, in response to injury."
BMGC_PW0811,BMG_PW3185,,"Hippo signaling is an evolutionarily conserved signaling pathway that controls organ size from flies to humans. In humans and mice, the pathway consists of the MST1 and MST2 kinases, their cofactor Salvador and LATS1 and LATS2. In response to high cell densities, activated LATS1/2 phosphorylates the transcriptional coactivators YAP and TAZ, promoting its cytoplasmic localization, leading to cell apoptosis and restricting organ size overgrowth. When the Hippo pathway is inactivated at low cell density, YAP/TAZ translocates into the nucleus to bind to the transcription enhancer factor (TEAD/TEF) family of transcriptional factors to promote cell growth and proliferation. YAP/TAZ also interacts with other transcriptional factors or signaling molecules, by which Hippo pathway-mediated processes are interconnected with those of other key signaling cascades, such as those mediated by TGF-beta and Wnt growth factors.","Human Hippo signaling is a network of reactions that regulates cell proliferation and apoptosis, centered on a three-step kinase cascade. The cascade was discovered by analysis of Drosophila mutations that lead to tissue overgrowth, and human homologues of its components have since been identified and characterized at a molecular level. Data from studies of mice carrying knockout mutant alleles of the genes as well as from studies of somatic mutations in these genes in human tumors are consistent with the conclusion that in mammals, as in flies, the Hippo cascade is required for normal regulation of cell proliferation and defects in the pathway are associated with cell overgrowth and tumorigenesis (Oh and Irvine 2010; Pan 2010; Zhao et al. 2010). This group of reactions is also notable for its abundance of protein:protein interactions mediated by WW domains and PPxY sequence motifs (Sudol and Harvey 2010). There are two human homologues of each of the three Drosophila kinases, whose functions are well conserved: expression of human proteins rescues fly mutants. The two members of each pair of human homologues have biochemically indistinguishable functions. Autophosphorylated STK3 (MST2) and STK4 (MST1) (homologues of Drosophila Hippo) catalyze the phosphorylation and activation of LATS1 and LATS2 (homologues of Drosophila Warts) and of the accessory proteins MOB1A and MOB1B (homologues of Drosophila Mats). LATS1 and LATS2 in turn catalyze the phosphorylation of the transcriptional co-activators YAP1 and WWTR1 (TAZ) (homologues of Drosophila Yorkie). In their unphosphorylated states, YAP1 and WWTR1 freely enter the nucleus and function as transcriptional co-activators. In their phosphorylated states, however, YAP1 and WWTR1 are instead bound by 14-3-3 proteins, YWHAB and YWHAE respectively, and sequestered in the cytosol. Several accessory proteins are required for the three-step kinase cascade to function. STK3 (MST2) and STK4 (MST1) each form a complex with SAV1 (homologue of Drosophila Salvador), and LATS1 and LATS2 form complexes with MOB1A and MOB1B (homologues of Drosophila Mats). In Drosophila a complex of three proteins, Kibra, Expanded, and Merlin, can trigger the Hippo cascade. A human homologue of Kibra, WWC1, has been identified and indirect evidence suggests that it can regulate the human Hippo pathway (Xiao et al. 2011). A molecular mechanism for this interaction has not yet been worked out and the molecular steps that trigger the Hippo kinase cascade in humans are unknown. Four additional processes related to human Hippo signaling, although incompletely characterized, have been described in sufficient detail to allow their annotation. All are of physiological interest as they are likely to be parts of mechanisms by which Hippo signaling is modulated or functionally linked to other signaling processes. First, the caspase 3 protease cleaves STK3 (MST2) and STK4 (MST1), releasing inhibitory carboxyterminal domains in each case, leading to increased kinase activity and YAP1 / TAZ phosphorylation (Lee et al. 2001). Second, cytosolic AMOT (angiomotin) proteins can bind YAP1 and WWTR1 (TAZ) in their unphosphorylated states, a process that may provide a Hippo-independent mechanism to down-regulate the activities of these proteins (Chan et al. 2011). Third, WWTR1 (TAZ) and YAP1 bind ZO-1 and 2 proteins (Remue et al. 2010; Oka et al. 2010). Fourth, phosphorylated WWTR1 (TAZ) binds and sequesters DVL2, providing a molecular link between Hippo and Wnt signaling (Varelas et al. 2010)."
BMGC_PW0812,BMG_PW3186,,"Phagocytosis plays an essential role in host-defense mechanisms through the uptake and destruction of infectious pathogens. Specialized cell types including macrophages, neutrophils, and monocytes take part in this process in higher organisms. After opsonization with antibodies (IgG), foreign extracellular materials are recognized by Fc gamma receptors. Cross-linking of Fc gamma receptors initiates a variety of signals mediated by tyrosine phosphorylation of multiple proteins, which lead through the actin cytoskeleton rearrangements and membrane remodeling to the formation of phagosomes. Nascent phagosomes undergo a process of maturation that involves fusion with lysosomes. The acquisition of lysosomal proteases and release of reactive oxygen species are crucial for digestion of engulfed materials in phagosomes.","Phagocytosis is one of the important innate immune responses that function to eliminate invading infectious agents. Monocytes, macrophages, and neutrophils are the professional phagocytic cells. Phagocytosis is a complex process involving the recognition of invading foreign particles by specific types of phagocytic receptors and the subsequent internalization of the particles. Fc gamma receptors (FCGRs) are among the best studied phagocytic receptors that bind to Fc portion of immunoglobulin G (IgG). Through their antigen binding F(ab) end, antibodies bind to specific antigen while their constant (Fc) region binds to FCGRs on phagocytes. The clustering of FCGRs by IgG antibodies on the phagocyte initiates a variety of signals, which lead, through the reorganisation of actin cytoskeleton and membrane remodelling, to the formation of pseudopod and phagosome. Fc gamma receptors are classified into three classes: FCGRI, FCGRII and FCGRIII. Each class of these FCGRs consists of several individual isoforms. Among all these isoforms FCGRI, FCGRIIA and FCGRIIIA, are able to mediate phagocytosis (Joshi et al. 2006, Garcia Garcia & Rosales 2002, Nimmerjahn & Ravetch 2006)."
BMGC_PW0813,BMG_PW3187,,,"Cross-linking of FCGRs with IgG coated immune complexes results in tyrosine phosphorylation of the immuno tyrosine activation motif (ITAMs) of the rececptor by membrane-bound tyrosine kinases of the SRC family. The phosphorylated ITAM tyrosines serve as docking sites for Src homology 2 (SH2) domain-containing SYK kinase. Recruitment and activation of SYK is critical for FCGR-mediated signaling in phagocytosis, but the exact role of SYK in this process is unclear. Activated SYK then transmits downstream signals leading to actin polymerization and particle internalization."
BMGC_PW0814,BMG_PW3188,,,The actin cytoskeleton is fundamental for phagocytosis and members of the Rho family GTPases RAC and CDC42 are involved in actin cytoskeletal regulation leading to pseudopod extension. Active RAC and CDC42 exert their action through the members of WASP family proteins (WASP/N-WASP/WAVE) and ARP2/3 complex. Actin filaments move from the bottom toward the top of the phagocytic cup during pseudopod extension.
BMGC_PW0815,BMG_PW3189,,,"Phospholipases play an integral role in phagocytosis by generating essential second messengers. An early step in phagocytic signaling is the association of PIP2 and IP3 with the phagocytic cup. These are formed by the activity of phosphoinositol kinases and phospholipases. PI3K is has been shown to accumulate at phagocytic cups and converts PI (4,5)P2 to PI (3,4,5)P3. These phosphoinositides are capable of binding and increasing the activity of proteins that regulate the actin cytoskeleton. Phospholipases are lipid modifying enzymes that produce lipid mediators such as diacylglycerol (DAG), arachidonic acid (AA) and IP3. Phopsholipases PLA, PLC and PLD have been shown to be involved in antibody (IgG) mediated phagocytosis. The PLC product IP3 stimulates release of calcium from the endoplasmic reticulum. This Ca+2 concentration increase is greatest in the cytoplasm surrounding the phagocytic cup. Calcium is involved in the various stages of phagosome formation, including phagocytic ingestion and phagosome maturation."
BMGC_PW0816,BMG_PW3190,,,"YAP1 and WWTR1 (TAZ) are transcriptional co-activators, both homologues of the Drosophila Yorkie protein. They both interact with members of the TEAD family of transcription factors, and WWTR1 interacts as well with TBX5 and RUNX2, to promote gene expression. Their transcriptional targets include genes critical to regulation of cell proliferation and apoptosis. Their subcellular location is regulated by the Hippo signaling cascade: phosphorylation mediated by this cascade leads to the cytosolic sequestration of both proteins (Murakami et al. 2005; Oh and Irvine 2010)."
BMGC_PW0817,BMG_PW3191,,,"The FGFR3 gene has been shown to be subject to activating mutations and gene amplification leading to a variety of proliferative and developmental disorders depending on whether these events occur in the germline or arise somatically. As is the case for the other receptors, many of the activating mutations that are seen in FGFR3-related cancers mimic the germline FGFR3 mutations that give rise to autosomal skeletal disorders and include both ligand-dependent and independent mechanisms (reviewed in Webster and Donoghue, 1997; Burke et al, 1998; Wesche et al, 2011). In addition to activating mutations, the FGFR3 gene is subject to a translocation event in 15% of multiple myelomas (Avet-Loiseau et al, 1998; Chesi et al, 1997). This chromosomal rearrangement puts the FGFR3 gene under the control of the highly active IGH promoter and promotes overexpression and constitutive activation of FGFR3 (Otsuki et al, 1999). In a small proportion of multiple myelomas, the translocation event is accompanied by activating mutations in the FGFR3 coding sequence (Chesi et al, 1997; Onwuazor et al, 2003; Ronchetti et al, 2001). Finally, FGFR3 is subject to fusion events in a number of cancers, including lung, bladder and glioblastoma (Singh et al, 2012; Parker et al, 2013; Williams et al, 2013; Wu et al, 2013; Capelletti et al, 2014; Yuan et al, 2014; Wang et al, 2014; Carneiro et al, 2015; reviewed in Parker et al, 2014). These fusions are constitutively active based on dimerization domains provided by the fusion partners and support transformation and proliferation through downstream signaling pathways such as ERK and AKT (Singh et al, 2012; Williams et al, 2013; Parker et al, 2013; reviewed in Parker et al, 2014)."
BMGC_PW0818,BMG_PW3193,,,"Autosomal dominant mutations in FGFR2 are associated with the development of a range of skeletal disorders including Beare-Stevensen cutis gyrata syndrome, Pfeiffer syndrome, Jackson-Weiss syndrome, Crouzon syndrome and Apert Syndrome (reveiwed in Burke, 1998; Webster and Donoghue 1997; Cunningham, 2007). Mutations that give rise to Crouzon, Jackson-Weiss and Pfeiffer syndromes tend to cluster in the third Ig-like domain of the receptor, either in exon IIIa (shared by the IIIb and the IIIc isoforms) or in the FGFR2c-specific exon IIIc. These mutations frequently involve creation or removal of a cysteine residue, leading to the formation of an unpaired cysteine residue that is thought to promote intramolecular dimerization and thus constitutive, ligand-independent activation (reviewed in Burke, 1998; Webster and Donoghue, 1997; Cunningham, 2007). Mutations in FGFR2 that give rise to Apert Syndrome cluster to the highly conserved Pro-Ser dipeptide in the IgII-Ig III linker; mutations in the paralogous residues of FGFR1 and 3 give rise to Pfeiffer and Muenke syndromes, respectively (Muenke, 1994; Wilkie, 1995; Bellus, 1996). Development of Beare-Stevensen cutis gyrata is associated with mutations in the transmembrane-proximal region of the receptor (Przylepa, 1996), and similar mutations in FGFR3 are linked to the development of thanatophoric dysplasia I (Tavormina, 1995a). These mutations all affect FGFR2 signaling without altering the intrinsic kinase activity of the receptor. Activating point mutations have also been identified in FGFR2 in ~15% of endometrial cancers, as well as to a lesser extent in ovarian and gastric cancers (Dutt, 2008; Pollock, 2007; Byron, 2010; Jang, 2001). These mutations are found largely in the extracellular region and in the kinase domain of the receptor, and parallel activating mutations seen in autosomal dominant disorders described above. Activating mutations in FGFR2 are thought to contribute to receptor activation through diverse mechanisms, including constitutive ligand-independent dimerization (Robertson, 1998), expanded range and affinity for ligand (Ibrahimi, 2004b; Yu, 2000) and enhanced kinase activity (Byron, 2008; Chen, 2007)."
BMGC_PW0819,BMG_PW3194,,,"eNOS activity is regulated by numerous post-translational modifications including phosphorylation and acylation, which also modulate its interactions with other proteins and its subcellular localization. In general, following myristoylation and palmitoylation, eNOS localizes to caveolae in the plasma membrane, where in resting cells, it is bound to caveolin and remains inactive. Several agonists that raise intracellular calcium concentrations promote calmodulin binding to eNOS and the dissociation of caveolin from the enzyme, leading to an activated eNOS-calmodulin complex. Phosphorylation plays a significant role in regulating eNOS activity, especially the phosphorylation of Ser1177, located within the reductase domain, which increases enzyme activity by enhancing reductase activity and calcium sensitivity. In unstimulated, cultured endothelial cells, Ser1177 is rapidly phosphorylated following a variety of stimuli: fluid shear stress, insulin, estrogen, VEGF, or bradykinin. The kinases involved in this process depend upon the stimuli applied. For instance, shear stress phosphorylates Ser1177 by activating Akt and PKA; insulin activates both Akt and the AMP-activated protein kinase (AMPK); estrogen and VEGF mainly phosphorylate eNOS via Akt; whereas the bradykinin-induced phosphorylation of Ser1177 is mediated by CaMKII. When Ser1177 is phosphorylated, NO production is increased several-fold above basal levels. The phosphorylation of a threonine residue (Thr 495), located in the CaM binding domain, is associated with a decrease in eNOS activity. When this residue is dephosphorylated, substantially more CaM binds to eNOS and elevates enzyme activity. Stimuli associated with dephosphorylation of Thr495 (e.g., bradykinin, histamine, and Ca2+ ionophores) also increase Ca2+ levels resulting in the phosphorylation of Ser1177. Additional phosphorylation sites, such as Ser114 and Ser633, and tyrosine phosphorylation have all been detected, but their functional relevance remains unclear. It is speculated that the tyrosine phosphorylation of eNOS is unlikely to affect enzyme activity directly, but more likely to impact the protein-protein interactions with associated scaffolding and regulatory proteins."
BMGC_PW0820,BMG_PW3195,,,"eNOS traffic inducer (NOSTRIN) is a novel 506-amino acid eNOS-interacting protein. Along with a decrease in eNOS activity, NOSTRIN causes translocation of eNOS from the plasma membrane to intracellular vesicular structures. NOSTRIN functions as an adaptor protein through homotrimerization and recruitment of eNOS, dynamin-2, and N-WASP to its SH3 domain. Studies indicated that NOSTRIN may facilitate vesicle fission and endocytosis of eNOS by coordinating the function of dynamin and N-WASP, which in turn, recruits the Arp2/3 complex, initiating actin filament polymerization. Overall, this process is thought to occur via caveolar endocytosis."
BMGC_PW0821,BMG_PW3197,,,"COPII components (known as Sec13p, Sec23p, Sec24p, Sec31p, and Sar1p in yeast) traffic cargo from the endoplasmic reticulum to the ER-Golgi intermediate compartment (ERGIC). COPII-coated vesicles were originally discovered in the yeast Saccharomyces cerevisiae using genetic approaches coupled with a cell-free assay. The mammalian counterpart of this pathway is represented here. Newly synthesized proteins destined for secretion are sorted into COPII-coated vesicles at specialized regions of the ER. These vesicles leave the ER, become uncoated and subsequently fuse with the ERGIC membrane."
BMGC_PW0822,BMG_PW3198,,,"The mitochondrial pyruvate dehydrogenase (PDH) complex catalyzes the oxidative decarboxylation of pyruvate, linking glycolysis to the tricarboxylic acid cycle and fatty acid synthesis. PDH inactivation is crucial for glucose conservation when glucose is scarce, while adequate PDH activity is required to allow both ATP and fatty acid production from glucose. The mechanisms that control human PDH activity include its phosphorylation (inactivation) by pyruvate dehydrogenase kinases (PDK 1-4) and its dephosphorylation (activation, reactivation) by pyruvate dehydrogenase phosphate phosphatases (PDP 1 and 2). Isoform-specific differences in kinetic parameters, regulation, and phosphorylation site specificity of the PDKs introduce variations in the regulation of PDC activity in differing endocrine and metabolic states (Sugden and Holness 2003). Further, PDH is inhibited by SIRT4 and the drug dichloroacetic acid (DCA)."
BMGC_PW0823,BMG_PW3199,,,"There are two major classes of polyunsaturated fatty acids (PUFAs): the omega-3 (n-3) and the omega-6 (n-6) fatty acids, where the number corresponds to the position of the first double bond proximate to the methyl end of the fatty acid. Omega-3 and omega-6 fatty acids are considered essential fatty acids. Humans cannot synthesize them, instead they are supplied through diet. Linoleic acid (LA, 18:2(n-6)), a major component of omega-6 fatty acids and alpha-linolenic acid (ALA, 18:2(n-3)) a major component of omega-3 fatty acids are the two main dietary essential fatty acids (EFAs) in humans. ALA and LA obtained from diet are converted in the body into their longer chain and more unsaturated omega-3 and omega-6 products by a series of desaturation and elongation steps. Metabolism of ALA and LA to their corresponding products is mediated via common enzyme systems. In humans ALA is finally converted to docosahexaenoic acid (DHA, C22:6(n-3)), and LA is converted to docosapentaenoic acid (DPA, C22:5(n-6)). The intermediary omega-3 and omega-6 series fatty acids play a significant role in health and disease by generating potent modulatory molecules for inflammatory responses, including eicosanoids (prostaglandins, and leukotrienes), and cytokines (interleukins) and affecting the gene expression of various bioactive molecules (Kapoor & Huang 2006, Sprecher 2002, Burdge 2006)."
BMGC_PW0824,BMG_PW3201,,,"p75NTR is a key regulator of neuronal apoptosis, both during development and after injury. Apoptosis is triggered by binding of either mature neurotrophin or proneurotrophin (proNGF, proBDNF). ProNGF is at least 10 times more potent than mature NGF in inducing apoptosis. TRKA signalling protects neurons from apoptosis. The molecular mechanisms involved in p75NTR-apoptosis are not well understood. The death signalling requires activation of c-JUN N-terminal Kinase (JNK), as well as transcriptional events. JNK activation appears to involve the receptor interacting proteins TRAF6, NRAGE, and Rac. The transcription events are thought to be regulated by another p75-interacting protein, NRIF. Two other p75-interacting proteins, NADE and Necdin, have been implicated in apoptosis, but their role is less clear."
BMGC_PW0825,BMG_PW3203,,,"NADE protein (p75NTR-associated cell death executor) may induce cell death upon NGF binding, but not BDNF, NT3, or NT4/5 binding, to p75NTR. The NADE-dependent apoptosis is modulated by the 14-3-3-epsilon protein (Kimura MT et al, 2001)."
BMGC_PW0826,BMG_PW3204,,,"NRIF (nuclear receptor-interacting factor) is a DNA binding protein that is essential for p75-mediated apoptosis in retina and sympathetic neurons. Neurotrophin or proneurotrophin binding to p75TR induces nuclear translocation of NRIF, which involves gamma-secretase cleavage of p75NTR ICD (Intra Cellular Domain). Once in the nucleus, NRIF mediates apoptosis, probably by acting as transcription factor."
BMGC_PW0827,BMG_PW3205,,,"NF-kB activation involves recruitment at the cell membrane of several proteins such as RIP2, MYD88, IRAK1, TRAF6, p62 and atypical PKC by the NGF:p75NTR complex."
BMGC_PW0828,BMG_PW3206,,,"Upon activation in response to NGF, NF-kB moves to the nucleus, where it turns on genes that promote survival, and triggers the expression of HES1/5 to modulate dendritic growth."
BMGC_PW0829,BMG_PW3207,,,Complex formation between p75NTR and RHOA can leads to inhibition of RHOA activity and axonal growth.
BMGC_PW0830,BMG_PW3208,,,"Catecholamines and thyroxine are synthesized from tyrosine, and serotonin and melatonin from tryptophan."
BMGC_PW0831,BMG_PW3209,,,"More complex protein hormones have carbohydrate side chains and are called glycoprotein hormones. Hormones in this class are Follicle-stimulating hormone (FSH; follitropin), Luteinizing hormone (LH), Thyroid-stimulating hormone (TSH; thyrotropin) and human chorionic gonadotropin (hCG). The alpha subunit of glycoprotein hormones is a 92 aa peptide and serves as the alpha subunit for FSH, LH, hCG and TSH (Fiddes JC and Goodman HM, 1981). The beta subunits for these hormones are unique and confer biological specificity to them. These two subunits combine via disulphide bonding to produce the mature glycoprotein hormone dimer."
BMGC_PW0832,BMG_PW3211,,,Peptide hormones are peptides that are secreted directly into the blood stream (endocrine hormones). They are synthesized as precursors that require proteolytic processing (not discussed here) to generate the biologically active peptides that mediate neurotransmission and hormonal action. Glycoprotein hormones (those which include carbohydrate side-chains) and the processing of corticotropin are annotated here.
BMGC_PW0833,BMG_PW3212,,"Thyroid hormones triiodothyronine (T3) and thyroxine (T4) are essential for normal development, growth and metabolic homeostasis in all vertebrates, and synthesized in the thyroid gland. The functional unit of the thyroid gland is the follicle, delimited by a monolayer of thyrocytes. Polarized thyrocytes surround the follicular lumen; with their basal and apical surfaces facing the bloodstream and the lumen, respectively. To synthesize thyroid hormones, thyrocytes take up iodide at their basal side and concentrate it into the lumen. They also secrete in this lumen the specialized protein thyroglobulin (TG) which serves as a store for the hormones. In the follicular lumen oxidation of iodine, iodination of tyrosines (MIT, 3-monoiodotyrosine; DIT, 3,5-diiodotyrosine) and coupling of iodotyrosines takes place on tyrosine residues in TG, resulting in T3 and T4 synthesis. Iodinated TG is resorbed through the apical membrane and degraded to form T3/T4 in lysosomes; the T3/T4 is then secreted through the basal membrane.","Thyroxine (3,5,3',5'-tetraiodothyronine, T4) promotes normal growth and development. It also regulates heat and energy production. T4 is released from the thyroid gland, the largest endocrine organ in the human body. The primary hormone released is T4 although T3 (3,5,3'-triiodothyronine) is also released in small quantities. Tyrosine residues in thyroglobulin (a glycoprotein scaffold containing many tyrosine residues) are iodinated to form mono- or diiodo-tyrosine which can then couple to form either T3 or T4."
BMGC_PW0834,BMG_PW3213,,,"In astrocytic glutamate-glutamine cycle, the excess glutamate released by the pre-synaptic neuron in the synaptic cleft is transported into the astrocyte by a family glutamate transporters called the excitatory amino acid transporters 1 and 2, EAAT1 and EAAT2. Astrocytes carrying these transporters exist in close apposition to the synapse to clear excess glutamate to prevent excessive activation of neurons and hence neuronal death. Glutamate in astrocytes is converted to glutamine by glutamine synthetase. Glutamine is then transported into the extracellular space by system N transporters. The glutamate in the extracellular space is available for neuronal uptake."
BMGC_PW0835,BMG_PW3214,,,"Communication at the synapse involves the release of glutamate from the presynaptic neuron and its binding to glutamate receptors on the postsynaptic cell to generate a series of events that lead to propagation of the synaptic transmission. This process begins with the formation of synaptic vesicles in the presynaptic neuron, proceeds to the loading of glutamate into the vesicles, and concludes with the release of glutamate into the synaptic cleft. The glutamate life cycle in the neuron begins with the loading of the nascent synaptic vesicles with cytosolic glutamate with the help the transporter protein, VGLUT1, located in the synaptic vesicular membrane. Glutamate loaded vesicles are formed in the cytoplasm and then transported to a site close to the plasma membrane where the vesicle is docked with the help of several proteins. One of the key players in the docking process in Munc 18, which interacts with syntaxin (in the plasma membrane), MINT (Munc18 interacting molecule), and DOC2. These interactions along with the secondary interactions are needed for docking the synaptic vesicle to the plasma membrane. The docked synaptic vesicle is not ready for release until it undergoes molecular changes to prime it for fusion with the plasma membrane. Munc13 is one of the main players in the priming process. Munc 13 interacts with RIM (Rab3A interacting molecule) located in the synaptic vesicle. Munc 13 also interacts with DOC2. The precise molecular mechanisms of the interactions that result in docking versus priming are not clear and the docking and priming process have been combined in this annotation of this pathway. Once primed the synaptic vesicle is ready for release. Synaptic transmission involves an action potential that is generated in the presynaptic cell which induces the opening of voltage gated Ca2+ channels (VGCC) located in the plasma membrane of the presynaptic neuron. Typically N, P/Q and R type of VGCCs are involved in the neurotransmitter release. Ca2+ influx through these channels results in the rise of intracellular Ca2+ concentration. In the microdomain of glutamatergic synapses, the Ca2+ concentration could rise between 10-25 micro molar. Synaptotagmin, a Ca2+-binding protein located in the synaptic vesicular membrane, responds to the rise in the Ca2+ levels in the microdomain and induces a synaptic vesicle membrane curvature that favors vesicle fusion. Fusion of the synaptic vesicle with the plasma membrane is characterized by the formation of a trimeric trans-SNARE complex that involves VAMP2 from the synaptic vesicle membrane, and syntaxin and SNAP-25 from plasma membrane. Vesicle fusion incorporates the synaptic vesicle membrane into the plasma membrane, releasing the vesicle contents (glutamate) into the synaptic cleft. Postfusion the synaptic vesicle membrane proteins (VAMP2, Rab3A, VGLUT1, and synaptotagmin) are also found in the plasma membrane."
BMGC_PW0836,BMG_PW3215,,,"The properties of transcriptional networks in late stage (branching morphogenesis) pancreatic bud precursor cells are inferred from the properties of well-studied networks in mouse models. In mice, committed but undifferentiated epithelial cells are organized into branching ductal structures. At a molecular level, expression of Pdx1, Nkx2.2, and Nkx6.1 is reduced while Hnf6 expression remains high. Hnf6 mediates the continued expression of Onecut3 and Hnf1 beta and epithelial cell proliferation. As expression of Ngn3 (corresponds to human NEUROG3) rises, endocrine differentiation of the epithelial cells begins (Servitja and Ferrer 2004; Chakrabarti and Mirmira 2003)."
BMGC_PW0837,BMG_PW3216,,,"Two transcription factors, PDX1 and HNF1A, play key roles in maintaining the gene expression pattern characteristic of mature beta cells in the endocrine pancreas. Targets of these regulatory molecules include genes encoding insulin, the GLUT2 glucose transporter, the liver- (and pancreas) specific form of pyruvate kinase and other transcription factors including HNF4A, HNF4G, and FOXA3. PDX1 expression in turn is controlled by the activities of MAFA, FOXA2, and PAX6, and negatively regulated via AKT (Chakrabarti and Mirmira 2003; Servitja and Ferrer 2004)."
BMGC_PW0838,BMG_PW3218,,,"The properties of transcriptional networks early in the differentiation of human pancreatic cells are inferred from the properties of well-studied networks in mouse models. In mice, the first visible sign of pancreatic development is the appearance of pancreatic buds at about embryonic day 9. The cells in these buds are already committed to differentiate into specialized cells of the exocrine and endocrine pancreas. Expression of transcription factors including Hnf1b, Hnf6, and Pdx1, as well as responsiveness to Fgf10 (fibroblast growth factor 10), up-regulates the expression of factors including Ptf1, Onecut3, Lrh1, and Nkx6.1 (Servitja and Ferrer 2004; Chakrabarti and Mirmira 2003)."
BMGC_PW0839,BMG_PW3219,,,"PECAM-1/CD31 is a member of the immunoglobulin superfamily (IgSF) and has been implicated to mediate the adhesion and trans-endothelial migration of T-lymphocytes into the vascular wall, T cell activation and angiogenesis. It has six Ig homology domains within its extracellularly and an ITIM motif within its cytoplasmic region. PECAM-1 mediates cellular interactions by both homophilic and heterophilic interactions. The cytoplasmic domain of PECAM-1 contains tyrosine residues which serves as docking sites for recruitment of cytosolic signaling molecules. Under conditions of platelet activation, PECAM-1 is phosphorylated by Src kinase members. The tyrosine residues 663 and 686 are required for recruitment of the SH2 domain containing PTPs."
BMGC_PW0840,BMG_PW3220,,,"Basigin is a widely expressed transmembrane glycoprotein that belongs to the Ig superfamily and is highly enriched on the surface of epithelial cells. Basigin is involved in intercellular interactions involved in various immunologic phenomena, differentiation, and development, but a major function of basigin is stimulation of synthesis of several matrix metalloproteinases. Basigin also induces angiogenesis via stimulation of VEGF production. Basigin has an extracellular region with two Ig-like domains of which the N-term Ig-like domain is involved in interactions. It undergoes interactions between basigin molecules on opposing cells or on neighbouring cells. It also interacts with a variety of other proteins like caveolin-1, cyclophilins, integrins and annexin II that play important roles in cell proliferation, energy metabolism, migration, adhesion and motion, especially in cancer metastasis."
BMGC_PW0841,BMG_PW3221,,,"The Tie2/Tek receptor tyrosine kinase plays a pivotal role in vascular and hematopoietic development and is expressed exclusively on endothelial lineage. Tie2 interacts with a group of ligands belonging to angiopoietin family and undergoes activation. These ligands show opposing actions, angiopoietin 1 and angiopoietin 4 stimulate the Tie2 phosphorylation and angiopoietin 2 inhibits it. Upon tyrosine phosphorylation Tie2 acts as a scaffold for various signaling proteins involved in different signal transduction cascades that can effect survival of endothelium and angiogenic sprout formation."
BMGC_PW0842,BMG_PW3222,,,"In this module, the biology of various types of regulatory non-coding RNAs are described. Biogenesis and functions of small interfering RNAs (siRNAs) and microRNAs (miRNAs) are annotated. Biogenesis of PIWI-interacting small RNAs (piRNAs) and tRNA-derived small RNAs (tsRNAs) are also annotated."
BMGC_PW0843,BMG_PW3223,,,"The unphosphorylated form of FOXO1A shuttles between the nucleus and cytoplasm, maintaining a substantial concentration of this protein in the nucleoplasm, where it functions as a transcription factor. Phosphorylation of the protein, catalyzed by activated AKT, causes its exclusion from the nucleus (Zhang et al. 2002)."
BMGC_PW0844,BMG_PW3225,,,"Stimulation of cell death by PAK-2 requires the generation and stabilization of the caspase-activated form, PAK-2p34 (Walter et al., 1998;Jakobi et al., 2003). Levels of proteolytically activated PAK-2p34 protein are controlled by ubiquitin-mediated proteolysis. PAK-2p34 but not full-length PAK-2 is degraded by the 26 S proteasome (Jakobi et al., 2003). It is not known whether ubiquitination and degradation of PAK-2p34 occurs in the cytoplasm or in the nucleus."
BMGC_PW0845,BMG_PW3227,,,"All organisms are constantly exposed to foreign chemicals every day. These can be man-made (drugs, industrial chemicals) or natural (alkaloids, toxins from plants and animals). Uptake is usually via ingestion but inhalation and transdermal routes are also common. The very nature of many chemicals that make them suitable for uptake by these routes, in other words their lipophilicty (favours fat solubility) is also the main reason organisms have developed mechanisms that convert them to hydrophilic (favours water solubility) compounds which are readily excreted via bile and urine. Otherwise, lipophilic chemicals would accumulate in the body and overwhelm defense mechanisms. This process is called biotransformation and is catalyzed by enzymes mainly in the liver of higher organisms but a number of other organs have considerable ability to process xenobiotica such as kidneys, gut and lungs. As well as xenobiotics, many endogenous compounds are commonly eliminated by this process. This mechanism is of ancient origin and a major factor for its development in animals is plants. Most animals are plant eaters and thus are subject to a huge variety of chemical compounds which plants produce to stop themselves being eaten. This complex set of enzymes have several features which make them ideal for biotransformation; (1) metabolites of the parent chemical are usually made more water soluble so it favours rapid excretion via bile and urine (2) the enzymes possess broad and overlapping specificity to be able to deal with newly exposed chemicals (3) metabolites of the parent generally don't have adverse biological effects. In the real world however, all these criteria have exceptions. Many chemicals are transformed into reactive metabolites. In pharmacology, the metabolites of some parent drugs exert the desired pharmacological effect but in the case of polycyclic aromatic hydrocarbons (PAHs), which can undergo epoxidation, it results in the formation of an electrophile which can attack proteins and DNA. Metabolism of xenobiotica occurs in several steps called Phase 1 (functionalization) and Phase 2 (conjugation). To improve water solubility, a functional group is added to or exposed on the chemical in one or more steps (Phase 1) to which hydrophilic conjugating species can be added (Phase 2). Functional groups can either be electrophilic (epoxides, carbonyl groups) or nucleophilic (hydroxyls, amino and sulfhydryl groups, carboxylic groups) (see picture). Once chemicals undergo functionalization, the electrophilic or nucleophilic species can be detrimental to biological systems. Electrophiles can react with electron-rich macromolecules such as proteins, DNA and RNA by covalent interaction whilst nucleophiles have the potential to interact with biological receptors. That's why conjugation is so important as it mops up these potentially reactive species. Many chemicals, when exposed to certain metabolizing enzymes can induce those enzymes, a process called enzyme induction. The effect of this is that these chemicals accelerate their own biotransformation and excretion. The reverse is also true where some chemicals cause enzyme inhibition. Some other factors that alter enzyme levels are sex, age and genetic predisposition. Between species, there can be considerable differences in biotransformation ability which is a problem faced by drug researchers interpreting toxicological results to humans."
BMGC_PW0846,BMG_PW3228,,,"The P450 isozyme system is the major phase 1 biotransforming system in man, accounting for more than 90% of drug biotransformations. This system has huge catalytic versatility and a broad substrate specificity, acting upon xenobiotica and endogenous compounds. It is also called the mixed-function oxidase system, the P450 monooxygenases and the heme-thiolate protein system. All P450 enzymes are a group of heme-containing isozymes which are located on the membrane of the smooth endoplasmic reticulum. They can be found in all tissues of the human body but are most concentrated in the liver. The name ""cytochrome P450"" (CYP) is derived from the spectral absorbance maximum at 450nm when carbon monoxide binds to CYP in its reduced (ferrous, Fe2+) state. The basic reaction catalyzed by CYP is mono-oxygenation, that is the transfer of one oxygen atom from molecular oxygen to a substrate. The other oxygen atom is reduced to water during the reaction with the equivalents coming from the cofactor NADPH. The basic reaction is; RH (substrate) + O2 + NADPH + H+ = ROH (product) + H2O + NADP+ The end results of this reaction can be (N-)hydroxylation, epoxidation, heteroatom (N-, S-) oxygenation, heteroatom (N-, S-, O-) dealkylation, ester cleavage, isomerization, dehydrogenation, replacement by oxygen or even reduction under anaerobic conditions. The metabolites produced from these reactions can either be mere intermediates which have relatively little reactivity towards cellular sysytems and are readily conjugated, or, they can be disruptive to cellular systems. Indeed, inert compounds need to be prepared for conjugation and thus the formation of potentially reactive metabolites is in most cases unavoidable. There are 57 human CYPs (in 18 families and 42 subfamilies), mostly concentrated in the endoplasmic reticulum of liver cells although many tissues have them to some extent (Nelson DR et al, 2004). CYPs are grouped into 14 families according to their sequence similarity. Generally, enzymes in the same family share 40% sequence similarity and 55% within a subfamily. Nomenclature of P450s is as follows. CYP (to represent cytochrome P450 superfamily), followed by an arabic number for the family, a capital letter for the subfamily and finally a second arabic number to denote the isoenzyme. An example is CYP1A1 which is the first enzyme in subfamily A of cytochrome P450 family 1. The majority of the enzymes are present in the CYP1-4 families. CYP1-3 are primarily concerned with xenobiotic biotransformation whereas the other CYPs deal primarily with endogenous compounds. The CYP section is structured by the typical substrate they act upon. Of the 57 human CYPs, 7 encode mitochondrial enzymes, all involved in sterol biosynthesis. Of the remaining 50 microsomal enzymes, 20 act upon endogenous compounds, 15 on xenobiotics and 15 are the so-called ""orphan enzymes"" with no substrate identified. The P450 catalytic cycle (picture) shows the steps involved when a substrate binds to the enzyme. (1) The normal state of a P450 with the iron in its ferric [Fe3+] state. (2) The substrate binds to the enzyme. (3) The enzyme is reduced to the ferrous [Fe2+] state by the addition of an electron from NADPH cytochrome P450 reductase. The bound substrate facilitates this process. (4,5) Molecular oxygen binds and forms an Fe2+OOH complex with the addition of a proton and a second donation of an electron from either NADPH cytochrome P450 reductase or cytochrome b5. A second proton cleaves the Fe2+OOH complex to form water. (6) An unstable [FeO]3+ complex donates its oxygen to the substrate (7). The oxidised substrate is released and the enzyme returns to its initial state (1)."
BMGC_PW0847,BMG_PW3229,,,A number of CYPs can act upon vitamins.
BMGC_PW0848,BMG_PW3230,,,The CYP4 family are the main CYPs involved in the metabolism of long-chain fatty acids.
BMGC_PW0849,BMG_PW3232,,,"Approximately a quarter of the 57 human CYPs still remain ""orphans"" in the sense that their function, expression sites, and regulation are largely not elucidated. While there is enough experimental evidence to know that all these proteins get made and can catalyze CYP-like reactions in vitro, evidence of in vivo function and substrate specificity is insufficient to allow them to be placed in any of the classes in the functional scheme."
BMGC_PW0850,BMG_PW3233,,,"A number of CYPs take part in cholesterol biosynthesis and elimination, thus playing an important role in maintaining cholesterol homeostasis. Under normal physiological conditions, cholesterol intake (diet or synthesized de novo from acetyl CoA) equals cholesterol elimination (degraded to bile salts, secreted in bile and used in steroid hormone synthesis). These processes are under tight regulatory control and any disruption leads to increased cholesterol levels resulting in cardiovacular disease. The CYPs involved in cholesterol homeostasis could serve as potential targets for cholesterol-lowering drugs (Lewis 2004, Guengerich 2006, Pikuleva 2006)."
BMGC_PW0851,BMG_PW3234,,,"Arachidonic acid is metabolized via three major enzymatic pathways: cyclooxygenase, lipoxygenase, and cytochrome P450. The cytochrome P450 pathway metabolites are oxygenated metabolites of arachidonic acid."
BMGC_PW0852,BMG_PW3235,,,"Cytochrome P450 8B1 (CYP8B1, sterol 12-alpha- hydroxylase) has a broad substrate specificity including a number of 7-alpha- hydroxylated C27 steroids. It is also involved in bile acid synthesis and is responsible for the balance between the formation of cholic acid and chenodeoxycholic acid (Gafvels et al. 1999)."
BMGC_PW0853,BMG_PW3236,,,"CYP2E1 can metabolize and activate a large number of solvents and industrial monomers as well as drugs. This quality of CYP2E1 may make it an important determinant of human susceptibility to the toxic effects of industrial and environmental chemicals. Typical CYP2E1 substrates include acetaminophen, benzene, CCl4, halothane, ethanol and vinyl chloride. CYP2E1 contributes to oxidative stress by producing oxidising species called reactive oxygen species (ROS) which can lead to damage to mitochondria, DNA and initiate lipid peroxidation or even cell death."
BMGC_PW0854,BMG_PW3237,,,"Epigenetic processes regulate gene expression by modulating the frequency, rate, or extent of gene expression in a mitotically or meiotically heritable way that does not entail a change in the DNA sequence. Originally the definition applied only to heritability across generations but later also encompassed the heritable changes that occur during cellular differentiation within one organism. Molecular analysis shows epigenetic changes comprise covalent modifications, such as methylation and acetylation, to DNA and histones. RNA interference has been implicated in the initiation of some epigenetic changes, for example transcriptional silencing of transposons. Proteins which bind to the modified DNA and histones are then responsible for repressing transcription and for maintaining the epigenetic modifications during cell division. During differentiation, patterns of gene expression are established by polycomb complexes PRC1 and PRC2. PRC2 methylates histones and DNA to produce the initial marks of repression: trimethylated lysine-27 on histone H3 (H3K27me3) and 5-methylcytosine in DNA. PRC2, through its component EZH2 or, in some complexes, EZH1 trimethylates lysine-27 of histone H3. The H3K27me3 produced by PRC2 is bound by the Polycomb subunit of PRC1. PRC1 ubiquitinates histone H2A and maintains repression. PRC2 and other epigenetic systems modulate gene expression through DNA methyation, the transfer of a methyl group from S-adenosylmethionine to the 5 position of cytosine in DNA by a family of DNA methyltransferases (DNMTs): DNMT1, DNMT3A, and DNMT3B. In the reverse process TET1,2,3 and TDG demethylate DNA through the oxidation of the methyl group of 5-methylcytosine by TET enzymes and the excision of the oxidized product (5-formylcytosine or 5-carboxylcytosine) by TDG. Ribosomal RNA (rRNA) genes are activated and deactivated according to the metabolic requirements of the cell. Positive epigenetic regulation of rRNA expression occurs through chromatin modifications produced by activators such as ERCC6 (CSB), the B-WICH complex, and histone acetylases such as KAT2B (PCAF). Negative epigenetic regulation of rRNA expression occurs through chromatin modifications produced by repressors such as the eNoSC complex, SIRT1, and the NoRC complex. WDR5 is a component of six histone methyltransferases and three histone acetyltransferases involved in epigenetic regulation of gene expression (reviewed in Guarnaccia and Tansey 2018). Endogenous retroelements are transposable elements that transpose to new genomic locations via an RNA intermediate and reverse transcription. Retroelements are silenced epigenetically in the human genome by mechanisms that include PIWI-interacting small RNAs (piRNAs) that transcriptionally silence retroelements through an RNA interference mechanism, KRAB-ZFP zinc finger-type repressors that bind specific DNA sequences in retroelements, and the HUSH complex that recognizes retroelements through nascent RNA or through existing histone H3 lysine-9 trimethylation (Almeida et al. 2022)."
BMGC_PW0855,BMG_PW3238,,,"NICD1 produced by activation of NOTCH1 in response to Delta and Jagged ligands (DLL/JAG) presented in trans, traffics to the nucleus where it acts as a transcription regulator. In the nucleus, NICD1 displaces the NCOR corepressor complex from RBPJ (CSL). When bound to the co-repressor complex that includes NCOR proteins (NCOR1 and NCOR2) and HDAC histone deacetylases, RBPJ (CSL) represses transcription of NOTCH target genes (Kao et al. 1998, Zhou et al. 2000, Perissi et al. 2004, Perissi et al. 2008). Once the co-repressor complex is displaced, NICD1 recruits MAML (mastermind-like) to RBPJ, while MAML recruits histone acetyltransferases EP300 (p300) and PCAF, resulting in formation of the NOTCH coactivator complex that activates transcription from NOTCH regulatory elements. The minimal functional NOTCH coactivator complex that activates transcription from NOTCH regulatory elements is a heterotrimer composed of NICD, MAML and RBPJ (Fryer et al. 2002, Wallberg et al. 2002, Nam et al. 2006). NOTCH1 coactivator complex is known to activate transcription of HES1 (Jarriault et al. 1995), HES5 (Arnett et al. 2010), HEY genes (Fischer et al. 2004, Leimeister et al. 2000, Maier et al. 2000, Arnett et al. 2010) and MYC (Palomero et al. 2006) and likely regulates transcription of many other genes (Wang et al. 2011). NOTCH1 coactivator complex on any specific regulatory element may involve additional transcriptional regulatory proteins. HES1 binds TLE proteins, forming an evolutionarily conserved transcriptional corepressor involved in regulation of neurogenesis, segmentation and sex determination (Grbavec et al. 1996, Fisher et al. 1996, Paroush et al. 1994). After NOTCH1 coactivator complex is assembled on a NOTCH-responsive promoter, MAML (mastermind-like) recruits CDK8 in complex with cyclin C, triggering phosphorylation of conserved serine residues in TAD and PEST domains of NICD1 by CDK8. Phosphorylated NICD1 is recognized by the E3 ubiquitin ligase FBXW7 which ubiquitinates NICD1, leading to degradation of NICD1 and downregulation of NOTCH1 signaling. FBXW7-mediated ubiquitination and degradation of NOTCH1 depend on C-terminally located PEST domain sequences in NOTCH1 (Fryer et al. 2004, Oberg et al. 2001, Wu et al. 2001). The PEST domain of NOTCH1 and the substrate binding WD40 domain of FBXW7 are frequent targets of mutations in T-cell acute lymphoblastic leukemia - T-ALL (Welcker and Clurman 2008). NICD1, which normally has a short half-life, can be stabilized by binding to the hypoxia-inducable factor 1-alpha (HIF1A) which accumulates in the nucleus when oxygen levels are low. This results in HIF1A-induced inhibition of cellular differentiation that is NOTCH-dependent (Gustafsson et al. 2005)."
BMGC_PW0856,BMG_PW3239,,,"Mature NOTCH1 heterodimer on the cell surface is activated by one of its ligands: DLL1 (Cordle et al. 2008, Jarriault et al. 1998), DLL4 (Benedito et al. 2009), JAG1 (Li et al. 1998, Benedito et al. 2009) or JAG2 (Luo et al. 1997, Shimizu et al. 2000), expressed in trans on a neighboring cell. Thus, a ligand-expressing cell is a signal-sending cell, while the NOTCH1 expressing cell is a signal-receiving cell. If NOTCH1 has undergone Fringe modification in the Golgi, it is preferentially activated by Delta ligands (Yang et al. 2005), DLL1 and DLL4. Upon binding to NOTCH1 on a neighboring cell, NOTCH ligands are ubiquitinated by Mindbomb (MIB1 and MIB2) and/or Neuralized (NEURL and NEURL1B) E3 ubiquitin ligases and endocytosed (Koo et al. 2007, Koo et al. 2005, Itoh et al. 2003, Lai et al. 2001, Koutelou et al. 2008, Song et al. 2006). Endocytosis of ubiquitinated ligands is thought to mechanically stretch the bound NOTCH1 receptor, exposing a cleavage site S2 that is recognized by ADAM10 and/or ADAM17 metalloprotease (van Tetering et al. 2009, Brou et al. 2000, Hartmann et al. 2002, Pan et al. 1997). S2 cleavage of NOTCH1 produces the NEXT1 fragment which is further cleaved at an S3 cleavage site by the gamma-secretase complex, resulting in release of the NOTCH1 intracellular domain (NICD1) into the cytosol (de Strooper et al. 1999, Schroeter et al. 1998, Huppert et al. 2000). NICD1 produced by activation of NOTCH1 in response to in trans presented Delta and Jagged ligands (DLL/JAG) traffics to the nucleus where it acts as a transcription regulator. NOTCH1 signaling can also be activated by ligands other than DLL1, DLL4, JAG1 and JAG2. CNTN1 (Contactin-1), transiently expressed during central and peripheral nervous system development, activates NOTCH1 and NOTCH2 in trans, promoting oligodendrocyte maturation and myelination (Hu et al. 2003). DNER (Delta and Notch-like epidermal growth factor-related receptor) is a transmembrane protein specifically expressed in dendrites and cell bodies of postmitotic neurons. Activation of NOTCH1 by DNER in trans may play an important role in development of the central nervous system by influencing differentiation of astrocytes (Eiraku et al. 2005). Activation of NOTCH1 by both CNTN1 and DNER is Deltex (DTX)-dependent and results in gamma-secretase mediated release of NICD1. Three members of the Deltex protein family: DTX1, DTX2 and DTX4 possess a domain involved in binding cdc10/ankyrin repeats of NOTCH. DTX proteins are considered as positive regulators of NOTCH signaling, although the exact mechanism has not been elucidated (Matsuno et al. 1998, Kishi et al. 2001).In addition, DTX can mediate downregulation of NOTCH signaling by recruiting non-visual beta-arrestins to NOTCH (Mukherjee et al. 2005), thereby trigerring NOTCH ubiquitination. DTX proteins are negatively regulated by ITCH (AIP4) ubiquitin ligase (Chastagner et al. 2006). NOTCH1 signaling in the signal-receiving cell can be turned off in cis by expression of NOTCH ligands DLL/JAG (Cordle et al. 2008, Sprinzak et al. 2010), as well as DLK1 (Baladron et al. 2005, Bray et al. 2008). Formation of NOTCH1:ligand complexes in cis prevents interaction of NOTCH1 with ligands expressed in trans, resulting in the inhibition of NOTCH signaling. In the signal-sending cell, NOTCH signaling can be negatively regulated by the protein NUMB, which is asymmetrically distributed during cell division (Rhyu et al. 1994). NUMB recruits ITCH ubiquitin ligase to NOTCH1 and promotes sorting of NOTCH1 through late endosomes for degradation (McGill et al. 2009, Chastagner et al. 2008)."
BMGC_PW0857,BMG_PW3240,,,"Polycomb group proteins are responsible for the heritable repression of genes during development (Lee et al. 2006, Ku et al. 2008, reviewed in Simon and Kingston 2009, Margueron and Reinberg 2011, Di Croce and Helin 2013). Two major families of Polycomb complexes exist: Polycomb Repressive Complex 1 (PRC1) and Polycomb Repressive Complex 2 (PRC2). PRC1 and PRC2 each appear to comprise sets of distinct complexes that contain common core subunits and distinct accessory subunits (reviewed in Nayak et al. 2011). PRC2, through its component EZH2 or, in some complexes, EZH1 produces the initial molecular mark of repression, the trimethylation of lysine-27 of histone H3 (H3K27me3). How PRC2 is initially recruited to a locus remains unknown, however cytosine-guanine (CpG) motifs and transcripts have been suggested. Different mechanisms may be used at different loci. The trimethylated H3K27 produced by PRC2 is bound by the Polycomb subunit of PRC1. PRC1 ubiquitinates histone H2A and maintains repression."
BMGC_PW0858,BMG_PW3241,,,"Dopamine neurotransmitter cycle occurs in dopaminergic neurons. Dopamine is synthesized and loaded into the clathrin sculpted monoamine transport vesicles. The vesicles are docked, primed and fused with the plasmamembrane in the synapse to release dopamine into the synaptic cleft."
BMGC_PW0859,BMG_PW3242,,,"Activated epidermal growth factor receptors (EGFR) can stimulate phosphatidylinositol (PI) turnover. Activated EGFR can activate phospholipase C-gamma1 (PLC-gamma1, i.e. PLCG1) which hydrolyses phosphatidylinositol 4,5-bisphosphate (PIP2) to inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG). IP3 is instrumental in the release of calcium from intracellular stores and DAG is involved in protein kinase C activation."
BMGC_PW0860,BMG_PW3243,,,"Proteins found associated with microfibrils include vitronectin (Dahlback et al. 1990), latent transforming growth factor beta-binding proteins (Kielty et al. 2002, Munger & Sheppard 2011), emilin (Bressan et al. 1993, Mongiat et al. 2000), members of the microfibrillar-associated proteins (MFAPs, Gibson et al.1996), and fibulins (Roark et al. 1995, Yanagisawa et al. 2002). The significance of these interactions is not well understood but may help mediate elastin-fibrillin interactions during elastic fibre assembly. Proteoglycans such as versican (Isogai et al. 2002), biglycan, and decorin (Reinboth et al. 2002) can interact with the microfibrils. They confer specific properties including hydration, impact absorption, molecular sieving, regulation of cellular activities, mediation of growth factor association, and release and transport within the extracellular matrix (Buczek-Thomas et al. 2002). In addition, glycosaminoglycans have been shown to interact with tropoelastin through its lysine side chains (Wu et al. 1999) regulating tropoelastin assembly (Tu and Weiss, 2008)."
BMGC_PW0861,BMG_PW3244,,,"The epoxidation of arachidonate by cytochrome P450s (CYPs) results in the formation of unique bioactive lipid mediators termed epoxyeicosatrienoates (EETs). Each double bond has been shown to be susceptible to oxidation, resulting in 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET. The majority of the EET biological activities are diminished by the hydrolysis to the corresponding dihydroxyeicosatrienoates (DHET) (Capdevila et al. 2000, Buczynski et al. 2009, Vance & Vance 2008)."
BMGC_PW0862,BMG_PW3245,,,"5-hydroperoxy-eicosatetraenoic acid (5-HpETE), 5-hydroxyeicosatetraenoic acid (5S-HETE) and 5-oxo-eicosatetraenoic acid (5-oxoETE) are formed after the initial step of Arachidonate oxidation by arachidonate 5-lipoxygenase (ALOX5) (Buczynski et al. 2009, Vance & Vance 2008)."
BMGC_PW0863,BMG_PW3246,,,"Leukotrienes (LTs) are biologically active molecules formed in response to inflammatory stimuli. They cause contraction of bronchial smooth muscles, stimulation of vascular permeability, and attraction and activation of leukocytes. LTs were discovered in 1938 and were termed the ""slow release substance"" (SRS) until their structures were determined in 1979 and they were then renamed to leukotrienes. LTs are derived from arachidonate through action by arachidonate 5-lipoxygenase (ALOX5). Cysteinyl leukotrienes (LTC4, LTD4, and LTE4) are generated as products derived from leukotriene A4 (LTA4). Eoxins are generated from leukotrienes (LTs) and resemble cysteinyl leukotrienes but have a different three-dimensional structure (Murphy & Gijon 2007, Hammarstrom 1983, MA.Claesson 2009, Vance & Vance 2008, Buczynski et al. 2009)."
BMGC_PW0864,BMG_PW3248,,,"Lipoxins A4 (LXA4) and B4 (LXB4), structurally characterized from human neutrophils incubated with 15-hydroperoxy-eicosatetraenoic acid (15-HpETE), each contain three hydroxyl moieties and a conjugated tetraene. The third hydroxyl of LXA4 is positioned at C-6, and of LXB4 at C-14. The action of arachidonate 5-lipoxygenase (ALOX5), in concert with an arachidonate 12-lipoxygenase (ALOX12) or arachidonate 15-lipoxygenase (ALOX15) activity, has been shown to produce lipoxins by three distinct pathways. Neutrophil ALOX5 can produce and secrete leukotriene A4 (LTA4) that is taken up by platelets, where it is acted upon by ALOX12 to form lipoxins. Likewise, ALOX15s can generate either 15-hydroperoxy-eicosatetraenoic acid (15-HpETE) or 15-hydro-eicosatetraenoic acid (15-HETE) that can be taken up by monocytes and neutrophils, where highly expressed ALOX5 uses it to generate lipoxins. Finally, aspirin acetylated prostaglandin G/H synthase 2 (PTGS2), rendered unable to synthesize prostaglandins, can act as a 15-lipoxygenase. This leads to the formation of 15R-HETE and culminates in creation of epi-lipoxins, which have altered stereochemistry at the C-15 hydroxyl but similar biological potency (Chiang et al. 2006, Buczynski et al. 2009, Vance & Vance 2008, Stsiapanava et al. 2017)."
BMGC_PW0865,BMG_PW3249,,,"The 12-eicosatetraenoic acids: 12-hydroperoxy-eicosatetraenoate (12-HpETE), 12-hydroxyeicosatetraenoate (12-HETE) and 12-oxo-eicosatetraenoate (12-oxoETE) are formed after the initial step of arachidonate oxidation by the arachidonate 12 and 15 lipoxygenases (ALOX12, ALOX12B and ALOX15 respectively). This part of the pathway is bifurcated at the level of 12S-hydroperoxy-eicosatetraenoate (12S-HpETE), which can either be reduced to 12S-hydro-eicosatetraenoate (12S-HETE) or converted to hepoxilins (Buczynski et al. 2009, Vance & Vance 2008)."
BMGC_PW0866,BMG_PW3250,,,"The 15-eicosatetraenoates: 15-hydroperoxy-eicosatetraenoate (15-HpETE), 15-hydroxyeicosatetraenoate (15-HETE) and 15-oxo-eicosatetraenoate (15-oxoETE) are formed after the initial step of arachidonate oxidation by the arachidonate 15-lipoxygenases (ALOX15 and ALOX15B) (Buczynski et al. 2009, Vance & Vance 2008)."
BMGC_PW0867,BMG_PW3251,,,"Similar to the lipoxygenases, cytochrome P450 (CYP) enzymes catalyse the hydroxylation and epoxygenation of arachidonate. However, whereas lipoxygenases use an active non-heme iron to abstract hydrogen directly from arachidonate, CYPs contain a heme-iron active site that oxidizes its substrate by a different mechanism. They hydroxylate arachidonate between C-5 and C-15 to produce lipoxygenase-like hydroxyeicosatetraenoates (HETEs) and add a hydroxyl moiety to the sp3-hybridized omega-carbons to form a unique class of HETEs. The transfer of oxygen to the unstable arachidonate intermediate terminates the reaction by forming HETE or epoxy-eicosatrienoate (EETs), respectively (Capdevila et al. 2000, Buczynski et al. 2009, Vance & Vance 2008)."
BMGC_PW0868,BMG_PW3253,,,"Phosphorylated PPARGC1A (PGC-1alpha) does not bind DNA directly but instead interacts with other transcription factors, notably NRF1 and NRF2 (via HCF1). NRF1 and NRF2 together with PPARGC1A activate the transcription of nuclear-encoded, mitochondrially targeted proteins such as TFB2M, TFB1M, and TFAM. PGC-1beta and PPRC appear to act similarly to PGC-1alpha but have not been as well studied. Transcription of PPARGC1A itself is upregulated by CREB1 (in response to calcium), MEF2C/D, ATF2, and PPARGC1A. Transcription of PPARGC1A is repressed by NR1D1 (REV-ERBA)."
BMGC_PW0869,BMG_PW3254,,,"The transcriptional coactivator PPARGC1A (PGC-1alpha), one of the master regulators of mitochondrial biogenesis, is activated by phosphorylation. Energy depletion causes a reduction in ATP and an increase in AMP which activates AMPK. AMPK in turn phosphorylates PPARGC1A. Likewise, p38 MAPK is activated by muscle contraction (possibly via calcium and CaMKII) and phosphorylates PPARGC1A. PPARGC1A does not bind DNA directly, but rather interacts with other transcription factors. Deacetylation of PPARGC1A by SIRT1 appears to follow phosphorylation however the role of deacetylation is unresolved (Canto et al. 2009, Gurd et al. 2011, Philp et al. 2011)"
BMGC_PW0870,BMG_PW3255,,,"The extracellular matrix (ECM) is a network of macro-molecules that underlies all epithelia and endothelia and that surrounds all connective tissue cells. This matrix provides the mechanical strength and also influences the behavior and differentiation state of cells in contact with it. The ECM are diverse in composition, but they generally comprise a mixture of fibrillar proteins, polysaccharides synthesized, secreted and organized by neighboring cells. Collagens, fibronectin, and laminins are the principal components involved in cell matrix interactions; other components, such as vitronectin, thrombospondin, and osteopontin, although less abundant, are also important adhesive molecules. Integrins are the receptors that mediate cell adhesion to ECM. Integrins consists of one alpha and one beta subunit forming a noncovalently bound heterodimer. 18 alpha and 8 beta subunits have been identified in humans that combine to form 24 different receptors. The integrin dimers can be broadly divided into three families consisting of the beta1, beta2/beta7, and beta3/alphaV integrins. beta1 associates with 12 alpha-subunits and can be further divided into RGD-, collagen-, or laminin binding and the related alpha4/alpha9 integrins that recognise both matrix and vascular ligands. beta2/beta7 integrins are restricted to leukocytes and mediate cell-cell rather than cell-matrix interactions, although some recognize fibrinogen. The beta3/alphaV family members are all RGD receptors and comprise aIIbb3, an important receptor on platelets, and the remaining b-subunits, which all associate with alphaV. It is the collagen receptors and leukocyte-specific integrins that contain alpha A-domains."
BMGC_PW0871,BMG_PW3256,,,"Hyaluronan (HA) turnover can occur locally at the tissue of origin, where it is taken up by cells to be degraded, or released into the lymphatic and vascular systems, where it can be eliminated by the liver and kidneys. Uptake of HA into cells for degradation involves receptor-mediated processes. Once HA enters lysosomes, the acidic conditions favour hyaluronidases to cleave it into small oligosaccharides, the most common size being a tetrasaccharide. Beta-glucuronidases participate in degrading the small oligosaccharides in the lysosome. Ultimately, HA is degraded into its constituent sugars (glucuronic acid and N-acetylglucosamine) which can be used to reform many glycosaminoglycans (GAGs) when released from the lysosome. A third of the total HA content in humans is turned over daily and it has a short half life of minutes in circulation up to days in many tissues. The reasons why the body eliminates HA so rapidly are unknown but one possible explanation could be HA's role as a reactive oxygen species (ROS) scavenger. Removing these toxic compounds could explain the rapid elimination of HA (Lepperdinger et al. 2004, Menzel & Farr 1998, Erickson & Stern 2012, Stern 2003)."
BMGC_PW0872,BMG_PW3257,,,"Cytosolic levels of abacavir are determined by the balance of its facilitated diffusion into the cell mediated by organic cation transporters SLC22A1, 2, and 3, and its ATP-dependent efflux from cells mediated by ABCG2 and ABCB1 (Klaasen and Aleksunes 2010; Pan et al. 2007; Shaik et al. 2007)."
BMGC_PW0873,BMG_PW3259,,,"The bioactive prostaglandin (PG) signalling molecules, including PGA2, PGE2, PGF2a, and PGI2 (prostacyclin) are synthesised from arachidonate and its products by various prostaglandin synthase type enzymes. Prostaglandin H2 (PGH2) is the starting point for the synthesis of Thromboxanes (TXs) (Buczynski et al. 2009, Vance & Vance 2008). PGs and TXs are collectively known as the prostanoids. Two enzymes, PTGS1 and 2 (COX1 and 2) both catalyze the two-step conversion of arachidonate to PGH2. PTGS1 is constitutively expressed in many cell types while PTGS2 is induced in response to stress and mediates the syntheses of prostaglandins associated with pain, fever, and inflammation. Aspirin irreversibly inactivates both enzymes (though it acts more efficiently on PTGS1), explaining both its antiinflammatory effects and side effects like perturbed gastic acid secretion. Drugs like celecoxib, by specifically inhibiting PTGS2, have a strong anti-inflammatory effect with fewer side effects. These PTGS2-specific drugs, however, probably because of their effects on the balance of prostaglandin synthesis in platelets and endothelial cells, can also promote blood clot formation (Buczynski et al. 2009; Stables & Gilroy 2011)."
BMGC_PW0874,BMG_PW3260,,,"Free heme is damaging to tissues as it intercalates into biologic membranes, perturbing lipid bilayers and promoting the conversion of low-density lipoprotein to cytotoxic oxidized products. Moreover, it represents a source of redox-active iron that, participating in the Fenton reaction, generates oxygen radicals (reviewed in Gutteridge 1989). Free heme in plasma is mainly generated from hemoglobin released by circulating erythrocytes in pathologic conditions associated with intravascular hemolysis. Free hemoglobin in plasma is scavenged by the extracellular protein haptoglobin. Haptoglobin is produced by the liver and secreted into the plasma. Haptoglobin binds dimers of hemoglobin subunits rather than the intact tetramer (reviewed in Nielsen et al. 2010, Levy et al. 2010, Ascenzi et al. 2005, Madsen et al. 2001). The resulting haptoglobin:hemoglobin complex is then bound by CD163, expressed on plasma membranes of monocytes and macrophages, and endocytosed. When the buffering capacity of plasma haptoglobin is overwhelmed, heme is released from methemoglobin and it is bound by albumin and then transferred to hemopexin (reviewed in Chiabrando et al. 2011, Nielsen et al. 2010, Tolosano et al. 2010, Ascenzi et al. 2005, Tolosano and Altruda 2002). Hemopexin is produced mainly in the liver. Once secreted into the plasma, hemopexin binds heme and the hemopexin:heme complex is then preferentially delivered to liver hepatocytes, bound by LRP1 (CD91) and endocytosed."
BMGC_PW0875,BMG_PW3261,,,"DNAX activation protein of 12kDa (DAP12) is an immunoreceptor tyrosine-based activation motif (ITAM)-bearing adapter molecule that transduces activating signals in natural killer (NK) and myeloid cells. It mediates signalling for multiple cell-surface receptors expressed by these cells, associating with receptor chains through complementary charged transmembrane amino acids that form a salt-bridge in the context of the hydrophobic lipid bilayer (Lanier et al. 1998). DAP12 homodimers associate with a variety of receptors expressed by macrophages, monocytes and myeloid cells including TREM2, Siglec H and SIRP-beta, as well as activating KIR, LY49 and the NKG2C proteins expressed by NK cells. DAP12 is expressed at the cell surface, with most of the protein lying on the cytoplasmic side of the membrane (Turnbull & Colonna 2007, Tessarz & Cerwenka 2008)."
BMGC_PW0876,BMG_PW3262,,,"Flavin-containing monooxygenases (FMOs) are the second family of microsomal oxidative enzymes with broad and overlapping specificity. The major reactions FMOs catalyze are nucleophilic hetero-atom compounds such as nitrogen, sulfur or phosphorus as the hetero-atom to form N-oxides, S-oxides or P-oxides respectively. Despite the functional overlap with cytochrome P450s, the mechanism of action differs. FMOs bind and activate molecular oxygen before the substrate binds to the enzyme (picture). They also require flavin adenosine dinucleotide (FAD) as a cofactor. Unlike cytochrome P450 enzymes, FMOs are heat-labile, a useful way to distinguish which enzyme system is at work for researchers studying metabolism. Also, FMOs are not inducible by substrates, unlike the P450 enzymes.\n(1) NADPH binds to the enzyme and reduces the prosthetic group FAD to FADH2. NADP+ remains bound to the enzyme.\n(2) Incorporation of molecular oxygen to form a hydroperoxide.\n(3) A peroxide oxygen is transferred to the substrate.\n(4) Water is released.\n(5) NADP+ dissociates returning the enzyme to its initial state.\n\nTo date, there are 6 isozymes of FMO (FMO1-6) in humans, the most prominent and active one being FMO3. The FMO6 gene does not encode for a functional enzyme although it has the greatest sequence similarity with FMO3 (71%), whilst the others range from 50-58% sequence similarity with FMO3. FMO1-3 are the ones that exhibit activity towards nucleophiles, the others are insignificant in this respect (Cashman 2003, Krueger & Williams 2005)."
BMGC_PW0877,BMG_PW3263,,,"Scavenger receptors bind free extracellular ligands as the initial step in clearance of the ligands from the body (reviewed in Ascenzi et al. 2005, Areschoug and Gordon 2009, Nielsen et al. 2010). Some scavenger receptors, such as the CD163-haptoglobin system, are specific for only one ligand. Others, such as the SCARA receptors (SR-A receptors) are less specific, binding several ligands which share a common property, such as polyanionic charges. Brown and Goldstein originated the idea of receptors dedicated to scavenging aberrant molecules such as modified low density lipoprotein particles (Goldstein et al. 1979) and such receptors have been shown to participate in pathological processes such as atherosclerosis. Based on homology, scavenger receptors have been categorized into classes A-H (reviewed in Murphy et al. 2005)."
BMGC_PW0878,BMG_PW3264,,,"TGF-beta receptor signaling is downregulated by proteasome and lysosome-mediated degradation of ubiquitinated TGFBR1, SMAD2 and SMAD3, as well as by dephosphorylation of TGFBR1, SMAD2 and SMAD3. In the nucleus, SMAD2/3:SMAD4 complex stimulates transcription of SMAD7, an inhibitory SMAD (I-SMAD). SMAD7 binds phosphorylated TGFBR1 and competes with the binding of SMAD2 and SMAD3 (Hayashi et al. 1997, Nakao et al. 1997). Binding of SMAD7 to TGBR1 can be stabilized by STRAP, a protein that simultaneously binds SMAD7 and TGFBR1 (Datta et al. 2000). BAMBI simultaneously binds SMAD7 and activated TGFBR1, leading to downregulation of TGF-beta receptor complex signaling (Onichtchouk et al. 1999, Yan et al. 2009). In addition to competing with SMAD2/3 binding to TGFBR1, SMAD7 recruits protein phosphatase PP1 to phosphorylated TGFBR1, by binding to the PP1 regulatory subunit PPP1R15A (GADD34). PP1 dephosphorylates TGFBR1, preventing the activation of SMAD2/3 and propagation of TGF-beta signal (Shi et al. 2004). SMAD7 associates with several ubiquitin ligases, SMURF1 (Ebisawa et al. 2001, Suzuki et al. 2002, Tajima et al. 2003, Chong et al. 2010), SMURF2 (Kavsak et al. 2000, Ogunjimi et al. 2005), and NEDD4L (Kuratomi et al. 2005), and recruits them to phosphorylated TGFBR1 within TGFBR complex. SMURF1, SMURF2 and NEDD4L ubiquitinate TGFBR1 (and SMAD7), targeting TGFBR complex for proteasome and lysosome-dependent degradation (Ebisawa et al. 2001, Kavsak et al. 2000, Kuratomi et al. 2005). The ubiquitination of TGFBR1 can be reversed by deubiquitinating enzymes, UCHL5 (UCH37) and USP15, which may be recruited to ubiquitinated TGFBR1 by SMAD7 (Wicks et al. 2005, Eichhorn et al. 2012). Basal levels of SMAD2 and SMAD3 are maintained by SMURF2 and STUB1 ubiquitin ligases. SMURF2 is able to bind and ubiquitinate SMAD2, leading to SMAD2 degradation (Zhang et al. 2001), but this has been questioned by a recent study of Smurf2 knockout mice (Tang et al. 2011). STUB1 (CHIP) binds and ubiquitinates SMAD3, leading to SMAD3 degradation (Li et al. 2004, Xin et al. 2005). PMEPA1 can bind and sequester unphosphorylated SMAD2 and SMAD3, preventing their activation in response to TGF-beta signaling. In addition, PMEPA1 can bind and sequester phosphorylated SMAD2 and SMAD3, preventing formation of SMAD2/3:SMAD4 heterotrimer complexes (Watanabe et al. 2010). A protein phosphatase MTMR4, residing in the membrane of early endosomes, can dephosphorylate activated SMAD2 and SMAD3, preventing formation of SMAD2/3:SMAD4 complexes (Yu et al. 2010)."
BMGC_PW0879,BMG_PW3265,,,"Binding of transforming growth factor beta 1 (TGF beta 1, i.e. TGFB1) to TGF beta receptor type 2 (TGFBR2) activates TGF beta receptor signaling cascade. TGFB1 is posttranslationally processed by furin (Dubois et al. 1995) to form a homodimer and secreted to the extracellular space as part of the large latent complex (LLC). After the LLC disassembles in the extracellular space, dimeric TGFB1 becomes capable of binding to TGFBR2 (Annes et al. 2003, Keski Oja et al. 2004). Formation of TGFB1:TGFBR2 complex creates a binding pocket for TGF-beta receptor type-1 (TGFBR1) and TGFBR1 is recruited to the complex by binding to both TGFB1 and TGFBR2. This results in an active heterotetrameric TGF-beta receptor complex that consists of TGFB1 homodimer bound to two heterodimers of TGFBR1 and TGFBR2 (Wrana et al. 1992, Moustakas et al. 1993, Franzen et al. 1993). TGF-beta signaling can also occur through a single heterodimer of TGFBR1 and TGFBR2, although with decreased efficiency (Huang et al. 2011). TGFBR1 and TGFBR2 interact through their extracellular domains, which brings their cytoplasmic domains together. Ligand binding to extracellular receptor domains is cooperative, but no conformational change is seen from crystal structures of either TGFB1- or TGFB3-bound heterotetrameric receptor complexes (Groppe et al. 2008, Radaev et al. 2010). Activation of TGFBR1 by TGFBR2 in the absence of ligand is prevented by FKBP1A (FKBP12), a peptidyl-prolyl cis-trans isomerase. FKBP1A forms a complex with inactive TGFBR1 and dissociates from it only after TGFBR1 is recruited by TGFB1-bound TGFBR2 (Chen et al. 1997). Both TGFBR1 and TGFBR2 are receptor serine/threonine kinases. Formation of the hetero-tetrameric TGF-beta receptor complex (TGFBR) in response to TGFB1 binding induces receptor rotation, so that TGFBR2 and TGFBR1 cytoplasmic kinase domains face each other in a catalytically favourable configuration. TGFBR2 trans-phosphorylates serine residues at the conserved Gly-Ser-rich juxtapositioned domain (GS domain) of TGFBR1 (Wrana et al. 1994, Souchelnytskyi et al. 1996), activating TGFBR1. In addition to phosphorylation, TGFBR1 may also be sumoylated in response to TGF-beta stimulation. Sumoylation enhances TGFBR1 kinase activity (Kang et al. 2008). The activated TGFBR complex is internalized by clathrin-mediated endocytosis into early endosomes. With the assistance of SARA, an early endosome membrane protein, phosphorylated TGFBR1 within TGFBR complex recruits SMAD2 and/or SMAD3 , i.e. R-SMADs (Tsukazaki et al. 1998). TGFBR1 phosphorylates recruited SMAD2/3 on two C-terminal serine residues (Souchelnytskyi et al. 2001). The phosphorylation changes the conformation of SMAD2/3 MH2 domain, promoting dissociation of SMAD2/3 from SARA and TGFBR1 (Souchelnytskyi et al. 1997, Macias-Silva et al. 1996, Nakao et al. 1997) and formation of SMAD2/3 trimers (Chacko et al. 2004). The phosphorylated C-terminal tail of SMAD2/3 has high affinity for SMAD4 (Co-SMAD), inducing formation of SMAD2/3:SMAD4 heterotrimers, composed of two phosphorylated R-SMADs (SMAD2 and/or SMAD3) and SMAD4 (Co-SMAD). SMAD2/3:SMAD4 heterotrimers are energetically favored over R-SMAD trimers (Nakao et al. 1997, Qin et al. 2001, Kawabata et al. 1998, Chacko et al. 2004). SMAD2/3:SMAD4 heterotrimers translocate to the nucleus where they act as transcriptional regulators."
BMGC_PW0880,BMG_PW3266,,,"In normal cells and in the early stages of cancer development, signaling by TGF-beta plays a tumor suppressive role, as SMAD2/3:SMAD4-mediated transcription inhibits cell division by downregulating MYC oncogene transcription and stimulating transcription of CDKN2B tumor suppressor gene. In advanced cancers however, TGF-beta signaling promotes metastasis by stimulating epithelial to mesenchymal transition (EMT). TGFBR1 is recruited to tight junctions by binding PARD6A, a component of tight junctions. After TGF-beta stimulation, activated TGFBR2 binds TGFBR1 at tight junctions, and phosphorylates both TGFBR1 and PARD6A. Phosphorylated PARD6A recruits SMURF1 to tight junctions. SMURF1 is able to ubiquitinate RHOA, a component of tight junctions needed for tight junction maintenance, leading to disassembly of tight junctions, an important step in EMT (Wang et al. 2003, Ozdamar et al. 2005)."
BMGC_PW0881,BMG_PW3267,,,"In the nucleus, SMAD2/3:SMAD4 heterotrimer complex acts as a transcriptional regulator. The activity of SMAD2/3 complex is regulated both positively and negatively by association with other transcription factors (Chen et al. 2002, Varelas et al. 2008, Stroschein et al. 1999, Wotton et al. 1999). In addition, the activity of SMAD2/3:SMAD4 complex can be inhibited by nuclear protein phosphatases and ubiquitin ligases (Lin et al. 2006, Dupont et al. 2009)."
BMGC_PW0882,BMG_PW3268,,,"Transcriptional activity of SMAD2/3:SMAD4 heterotrimer can be inhibited by formation of a complex with SKI or SKIL (SNO), where SKI or SKIL recruit NCOR and possibly other transcriptional repressors to SMAD-binding promoter elements (Sun et al. 1999, Luo et al. 1999, Strochein et al. 1999). Higher levels of phosphorylated SMAD2 and SMAD3, however, may target SKI and SKIL for degradation (Strochein et al. 1999, Sun et al. 1999 PNAS, Bonni et al. 2001) through recruitment of SMURF2 (Bonni et al. 2001) or RNF111 i.e. Arkadia (Levy et al. 2007) ubiquitin ligases to SKI/SKIL by SMAD2/3. Therefore,the ratio of SMAD2/3 and SKI/SKIL determines the outcome: inhibition of SMAD2/3:SMAD4-mediated transcription or degradation of SKI/SKIL. SKI and SKIL are overexpressed in various cancer types and their oncogenic effect is connected with their ability to inhibit signaling by TGF-beta receptor complex. SMAD4 can be monoubiquitinated by a nuclear ubiquitin ligase TRIM33 (Ecto, Ectodermin, Tif1-gamma). Monoubiquitination of SMAD4 disrupts SMAD2/3:SMAD4 heterotrimers and leads to SMAD4 translocation to the cytosol. In the cytosol, SMAD4 can be deubiquitinated by USP9X (FAM), reversing TRIM33-mediated negative regulation (Dupont et al. 2009). Phosphorylation of the linker region of SMAD2 and SMAD3 by CDK8 or CDK9 primes SMAD2/3:SMAD4 complex for ubiquitination by NEDD4L and SMURF ubiquitin ligases. NEDD4L ubiquitinates SMAD2/3 and targets SMAD2/3:SMAD4 heterotrimer for degradation (Gao et al. 2009). SMURF2 monoubiquitinates SMAD2/3, leading to disruption of SMAD2/3:SMAD4 complexes (Tang et al. 2011). Transcriptional repressors TGIF1 and TGIF2 bind SMAD2/3:SMAD4 complexes and inhibit SMAD-mediated transcription by recruitment of histone deacetylase HDAC1 to SMAD-binding promoter elements (Wotton et al. 1999, Melhuish et al. 2001). PARP1 can attach poly ADP-ribosyl chains to SMAD3 and SMAD4 within SMAD2/3:SMAD4 heterotrimers. PARylated SMAD2/3:SMAD4 complexes are unable to bind SMAD-binding DNA elements (SBEs) (Lonn et al. 2010). Phosphorylated SMAD2 and SMAD3 can be dephosphorylated by PPM1A protein phosphatase, leading to dissociation of SMAD2/3 complexes and translocation of unphosphorylated SMAD2/3 to the cytosol (Lin et al. 2006)."
BMGC_PW0883,BMG_PW3269,,,"After phosphorylated SMAD2 and/or SMAD3 form a heterotrimer with SMAD4, SMAD2/3:SMAD4 complex translocates to the nucleus (Xu et al. 2000, Kurisaki et al. 2001, Xiao et al. 2003). In the nucleus, linker regions of SMAD2 and SMAD3 within SMAD2/3:SMAD4 complex can be phosphorylated by CDK8 associated with cyclin C (CDK8:CCNC) or CDK9 associated with cyclin T (CDK9:CCNT). CDK8/CDK9-mediated phosphorylation of SMAD2/3 enhances transcriptional activity of SMAD2/3:SMAD4 complex, but also primes it for ubiquitination and consequent degradation (Alarcon et al. 2009). The transfer of SMAD2/3:SMAD4 complex to the nucleus can be assisted by other proteins, such as WWTR1. In human embryonic cells, WWTR1 (TAZ) binds SMAD2/3:SMAD4 heterotrimer and mediates TGF-beta-dependent nuclear accumulation of SMAD2/3:SMAD4. The complex of WWTR1 and SMAD2/3:SMAD4 binds promoters of SMAD7 and SERPINE1 (PAI-1 i.e. plasminogen activator inhibitor 1) genes and stimulates their transcription (Varelas et al. 2008). Stimulation of SMAD7 transcription by SMAD2/3:SMAD4 represents a negative feedback loop in TGF-beta receptor signaling. SMAD7 can be downregulated by RNF111 ubiquitin ligase (Arkadia), which binds and ubiquitinates SMAD7, targeting it for degradation (Koinuma et al. 2003). SMAD2/3:SMAD4 heterotrimer also binds the complex of RBL1 (p107), E2F4/5 and TFDP1/2 (DP1/2). The resulting complex binds MYC promoter and inhibits MYC transcription. Inhibition of MYC transcription contributes to anti-proliferative effect of TGF-beta (Chen et al. 2002). SMAD2/3:SMAD4 heterotrimer also associates with transcription factor SP1. SMAD2/3:SMAD4:SP1 complex stimulates transcription of a CDK inhibitor CDKN2B (p15-INK4B), also contributing to the anti-proliferative effect of TGF-beta (Feng et al. 2000). MEN1 (menin), a transcription factor tumor suppressor mutated in a familial cancer syndrome multiple endocrine neoplasia type 1, forms a complex with SMAD2/3:SMAD4 heterotrimer, but transcriptional targets of SMAD2/3:SMAD4:MEN1 have not been elucidated (Kaji et al. 2001, Sowa et al. 2004, Canaff et al. 2012). JUNB is also an established transcriptional target of SMAD2/3:SMAD4 complex (Wong et al. 1999)."
BMGC_PW0884,BMG_PW3270,,,"Gastrin, through the action of diacylglycerol produced from downstream G alpha (q) events, transactivates EGFR via a PKC-mediated pathway by activation of MMP3 (Matrix Metalloproteinase 3) which allows formation of mature HBEGF (heparin-binding epidermal growth factor) by cleaving pro-HBEGF. Mature HBEGF is then free to bind the EGFR, resulting in EGFR activation (Dufresne et al. 2006, Liebmann 2011)."
BMGC_PW0885,BMG_PW3272,,,"In the nucleus, NICD2 forms a complex with RBPJ (CBF1, CSL) and MAML (mastermind). NICD2:RBPJ:MAML complex activates transcription from RBPJ-binding promoter elements (RBEs) (Wu et al. 2000). Besides NICD2, RBPJ and MAML, NOTCH2 coactivator complex likely includes other proteins, shown as components of the NOTCH1 coactivator complex. NOTCH2 coactivator complex directly stimulates transcription of HES1 and HES5 genes (Shimizu et al. 2002), both of which are known NOTCH1 targets. The promoter of FCER2 (CD23A) contains several RBEs that are occupied by NOTCH2 but not NOTCH1 coactivator complexes, and NOTCH2 activation stimulates FCER2 transcription. Overexpression of FCER2 (CD23A) is a hallmark of B-cell chronic lymphocytic leukemia (B-CLL) and correlates with the malfunction of apoptosis, which is thought be an underlying mechanism of B-CLL development. The Epstein-Barr virus protein EBNA2 can also activate FCER2 transcription through RBEs, possibly by mimicking NOTCH2 signaling (Hubmann et al. 2002). NOTCH2 coactivator complex occupies the proximal RBE of the GZMB (granzyme B) promoter and at the same time interacts with phosphorylated CREB1, bound to an adjacent CRE site. EP300 transcriptional coactivator is also recruited to this complex through association with CREB1 (Maekawa et al. 2008). NOTCH2 coactivator complex together with CREBP1 and EP300 stimulates transcription of GZMB (granzyme B), which is important for the cytotoxic function of CD8+ T-cells (Maekawa et al. 2008). There are indications that NOTCH2 genetically interacts with hepatocyte nuclear factor 1-beta (HNF1B) in kidney development (Massa et al. 2013, Heliot et al. 2013) and with hepatocyte nuclear factor 6 (HNF6) in bile duct formation (Vanderpool et al. 2012), but the exact nature of these genetic interactions has not been defined."
BMGC_PW0886,BMG_PW3284,,,"Collagen VII forms anchoring fibrils, composed of antiparallel dimers that connect the dermis to the epidermis (Bruckner-Tuderman 2009, Has & Kern 2010). During fibrillogenesis, the nascent type VII procollagen molecules dimerize in an antiparallel manner. The C-propeptide is then removed by Bone morphogenetic protein 1 (Rattenholl et al. 2002) and the processed antiparallel dimers laterally aggregate (Villone et al. 2008, Gordon & Hahn 2010)."
BMGC_PW0887,BMG_PW3285,,,"Class IA PI3K is a heterodimer of a p85 regulatory subunit (encoded by PIK3R1, PIK3R2 or PIK3R3) and a p110 catalytic subunit (encoded by PIK3CA, PIK3CB or PIK3CD). In the absence of activating signals, the regulatory subunit stabilizes the catalytic subunit while inhibiting its activity. The complex becomes activated when extracellular signals stimulate the phosphorylation of the cytoplasmic domains of transmembrane receptors or receptor-associated proteins. The p85 regulatory subunit binds phosphorylated motifs of activator proteins, which induces a conformational change that relieves p85-mediated inhibition of the p110 catalytic subunit and enables PI3K to phosphorylate PIP2 to form PIP3. The phosphoinositide kinase activity of PI3K is opposed by the phosphoinositide phosphatase activity of PTEN. PIP3 acts as a messenger that recruits PDPK1 (PDK1) and AKT (AKT1, AKT2 or AKT3) to the plasma membrane. PDPK1 also possesses a low affinity for PIP2, so small amounts of PDPK1 are always present at the membrane. Binding of AKT to PIP3 induces a conformational change that enables TORC2 complex to phosphorylate AKT at a conserved serine residue (S473 in AKT1). Phosphorylation at the serine residue enables AKT to bind to PDPK1 and exposes a conserved threonine residue (T308) that is phosphorylated by PDPK1. AKT phosphorylated at both serine and threonine residues dissociates from the plasma membrane and acts as a serine/threonine kinase that phosphorylates a number of cytosolic and nuclear targets involved in regulation of cell metabolism, survival and gene expression. For a recent review, please refer to Manning and Cantley, 2007. Signaling by PI3K/AKT is frequently constitutively activated in cancer. This activation can be via gain-of-function mutations in PI3KCA (encoding catalytic subunit p110alpha), PIK3R1 (encoding regulatory subunit p85alpha) and AKT1. The PI3K/AKT pathway can also be constitutively activated by loss-of-function mutations in tumor suppressor genes such as PTEN. Gain-of-function mutations activate PI3K signaling by diverse mechanisms. Mutations affecting the helical domain of PIK3CA and mutations affecting nSH2 and iSH2 domains of PIK3R1 impair inhibitory interactions between these two subunits while preserving their association. Mutations in the catalytic domain of PIK3CA enable the kinase to achieve an active conformation. PI3K complexes with gain-of-function mutations therefore produce PIP3 and activate downstream AKT in the absence of growth factors (Huang et al. 2007, Zhao et al. 2005, Miled et al. 2007, Horn et al. 2008, Sun et al. 2010, Jaiswal et al. 2009, Zhao and Vogt 2010, Urick et al. 2011). While AKT1 gene copy number, expression level and phosphorylation are often increased in cancer, only one low frequency point mutation has been repeatedly reported in cancer and functionally studied. This mutation represents a substitution of a glutamic acid residue with lysine at position 17 of AKT1, and acts by enabling AKT1 to bind PIP2. PIP2-bound AKT1 is phosphorylated by TORC2 complex and by PDPK1 that is always present at the plasma membrane, due to low affinity for PIP2. Therefore, E17K substitution abrogates the need for PI3K in AKT1 activation (Carpten et al. 2007, Landgraf et al. 2008). Loss-of-function mutations affecting the phosphatase domain of PTEN are frequently found in sporadic cancers (Kong et al. 1997, Lee et al. 1999, Han et al. 2000), as well as in PTEN hamartoma tumor syndromes (PHTS) (Marsh et al. 1998). PTEN can also be inactivated by gene deletion or epigenetic silencing, or indirectly by overexpression of microRNAs that target PTEN mRNA (Huse et al. 2009). Cells with deficient PTEN function have increased levels of PIP3, and therefore increased AKT activity. For a recent review, please refer to Hollander et al. 2011. Because of their clear involvement in human cancers, PI3K and AKT are targets of considerable interest in the development of small molecule inhibitors. Although none of the currently available inhibitors display preference for mutant variants of PIK3CA or AKT, several inhibitors targeting the wild-type kinases are undergoing clinical trials. These include dual PI3K/mTOR inhibitors, class I PI3K inhibitors, pan-PI3K inhibitors, and pan-AKT inhibitors. While none have yet been approved for clinical use, these agents show promise for future therapeutics. In addition, isoform-specific PI3K and AKT inhibitors are currently being developed, and may provide more specific treatments along with reduced side-effects. For a recent review, please refer to Liu et al. 2009."
BMGC_PW0888,BMG_PW3286,,,"Signaling by PI3K/AKT is frequently constitutively activated in cancer via gain-of-function mutations in one of the two PI3K subunits - PI3KCA (encoding the catalytic subunit p110alpha) or PIK3R1 (encoding the regulatory subunit p85alpha). Gain-of-function mutations activate PI3K signaling by diverse mechanisms. Mutations affecting the helical domain of PIK3CA and mutations affecting nSH2 and iSH2 domains of PIK3R1 impair inhibitory interactions between these two subunits while preserving their association. Mutations in the catalytic domain of PIK3CA enable the kinase to achieve an active conformation. PI3K complexes with gain-of-function mutations therefore produce PIP3 and activate downstream AKT in the absence of growth factors (Huang et al. 2007, Zhao et al. 2005, Miled et al. 2007, Horn et al. 2008, Sun et al. 2010, Jaiswal et al. 2009, Zhao and Vogt 2010, Urick et al. 2011)."
BMGC_PW0889,BMG_PW3287,,,"After removal of the N- and C-procollagen propeptides, fibrillar collagen molecules aggregate into microfibrillar arrays, stabilized by covalent intermolecular cross-links. These depend on the oxidative deamination of specific lysine or hydroxylysine residues in the telopeptide region by lysyl oxidase (LOX) with the subsequent spontaneous formation of covalent intermolecular cross-links (Pinnell & Martin 1968, Siegel et al. 1970, 1974, Maki 2009, Nishioka et al. 2012). Hydroxylysine is formed intracellularly by lysine hydroxylases (LH). There are different forms of LH responsible for hydroxylation of helical and telopeptide lysines (Royce & Barnes 1985, Knott et al.1997, Takaluoma et al. 2007, Myllyla 2007). The chemistry of the cross-links formed depends on whether lysines or hydroxylysines are present in the telopeptides (Barnes et al. 1974), which depends on the proportion of collagen lysines post-translationally converted to hydroxylysine by LH. The lysine pathway predominates in adult skin, cornea and sclera while the hydroxylysine pathway occurs primarily in bone, cartilage, ligament, tendons, embryonic skin and most connective tissues (Eyre 1987, Eyre & Wu 2005, Eyre et al. 2008). Oxidative deamination of lysine or hydroxylysine residues by LOX generates the allysine and hydroxyallysine aldehydes respectively. These can spontaneously react with either another aldehyde to form an aldol condensation product (intramolecular cross-link), or with an unmodified lysine or hydroxylysine residue to form intermolecular cross-links. The pathway of cross-linking is regulated primarily by the hydroxylation pattern of telopeptide and triple-helix domain lysine residues. When lysine residues are the source of aldehydes formed by lysyl oxidase the allysine cross-linking pathway leads to the formation of aldimine cross-links (Eyre & Wu 2005). These are stable at physiological conditions but readily cleaved at acid pH or elevated temperature. When hydroxylysine residues are the source of aldehydes formed by lysyl oxidase the hydroxyallysine cross-linking pathway leads to the formation of more stable ketoimine cross-links. Telopeptide lysine residues can be converted by LOX to allysine, which can react with a helical hydroxylysine residue forming the lysine aldehyde aldimine cross-link dehydro hydroxylysino norleucine (deHHLNL) (Bailey & Peach 1968, Eyre et al. 2008). If the telopeptide residue is hydroxylysine, the hydroxyallysine formed by LOX can react with a helical hydroxylysine forming the Schiff base, which spontaneously undergoes an Amadori rearrangement resulting in the ketoimine cross link hydroxylysino 5 ketonorleucine (HLKNL). This stable cross-link is formed in tissues where telopeptide residues are predominanly hydroxylated, such as foetal bone and cartilage, accounting for the relative insolubility of collagen from these tissues (Bailey et al. 1998). In bone, telopeptide hydroxyallysines can react with the epsilon-amino group of a helical lysine (Robins & Bailey 1975). The resulting Schiff base undergoes Amadori rearrangement to form lysino-hydroxynorleucine (LHNL). An alternative mechanism of maturation of ketoimine cross-links has been reported in cartilage leading to the formation of arginoline (Eyre et al. 2010). These divalent crosslinks greatly diminish as connective tissues mature, due to further spontaneous reactions (Bailey & Shimokomaki 1971, Robins & Bailey 1973) with neighbouring peptides that result in tri- and tetrafunctional cross-links. In mature tissues collagen cross-links are predominantly trivalent. The most common are pyridinoline or 3-hydroxypyridinium cross-links, namely hydroxylysyl-pyridinoline (HL-Pyr) and lysyl-pyridinoline (L-Pyr) cross-links (Eyre 1987, Ogawa et al. 1982, Fujimoto et al. 1978). HL-Pyr is formed from three hydroxylysine residues, HLKNL plus a further hydroxyallysine. It predominates in highly hydroxylated collagens such as type II collagen in cartilage. L-Pyr is formed from two hydroxylysines and a lysine, LKNL plus a further hydroxyallysine, found mostly in calcified tissues (Bailey et al. 1998). Trivalent collagen cross-links can also form as pyrroles, either Lysyl-Pyrrole (L-Pyrrole) or hydroxylysyl-pyrrole (HL-Pyrrole), respectively formed when LKNL or HLKNL react with allysine (Scott et al. 1981, Kuypers et al. 1992). A further three-way crosslink can form when DeH-HLNL reacts with histidine to form histidino-hydroxylysinonorleucine (HHL), found in skin and cornea (Yamauchi et al. 1987, 1996). This can react with an additional lysine to form the tetrafunctional cross-link histidinohydroxymerodesmosine (Reiser et al. 1992, Yamauchi et al. 1996). Another mechanism which could be involved in the cross-linking of collagen IV networks is the sulfilimine bond (Vanacore et al. 2009), catalyzed by peroxidasin, an enzyme found in basement membrane (Bhave 2012). To improve clarity inter-chain cross-linking is represented here for Collagen type I only. Although the formation of each type of cross-link is represented here as an independent event, the partial and random nature of lysine hydroxylation and subsequent lysyl oxidation means that any combination of these cross-linking events could occur within the same collagen fibril ."
BMGC_PW0890,BMG_PW3288,,,"Cells are subject to external molecular and physical stresses such as foreign molecules that perturb metabolic or signaling processes, and changes in temperature or pH. Cells are also subject to internal molecular stresses such as production of reactive metabolic byproducts. The ability of cells and tissues to modulate molecular processes in response to such stresses is essential to the maintenance of tissue homeostasis (Kultz 2005). Specific stress-related processes annotated here are cellular response to hypoxia, cellular response to heat stress, cellular senescence, HSP90 chaperone cycle for steroid hormone receptors (SHR) in the presence of ligand, response of EIF2AK1 (HRI) to heme deficiency, heme signaling, cellular response to chemical stress, cellular response to starvation, and unfolded protein response."
BMGC_PW0891,BMG_PW3289,,,"In mitotic prophase, the action of the condensin II complex enables initial chromosome condensation. The condensin II complex subunit NCAPD3 binds monomethylated histone H4 (H4K20me1), thereby associating with chromatin (Liu et al. 2010). Binding of the condensin II complex to chromatin is partially controlled by the presence of RB1 (Longworth et al. 2008). Two mechanisms contribute to the accumulation of H4K20me1 at mitotic entry. First, the activity of SETD8 histone methyltransferase peaks at G2/M transition (Nishioka et al. 2002, Rice et al. 2002, Wu et al. 2010). Second, the complex of CDK1 and cyclin B1 (CDK1:CCNB1) phosphorylates PHF8 histone demethylase at the start of mitosis, removing it from chromatin (Liu et al. 2010). Condensin II complex needs to be phosphorylated by the CDK1:CCNB1 complex, and then phosphorylated by PLK1, in order to efficiently condense prophase chromosomes (Abe et al. 2011)."
BMGC_PW0892,BMG_PW3292,,,"Binding of IGF1 (IGF-I) or IGF2 (IGF-II) to the extracellular alpha peptides of the type 1 insulin-like growth factor receptor (IGF1R) triggers the activation of two major signaling pathways: the SOS-RAS-RAF-MAPK (ERK) pathway and the PI3K-PKB (AKT) pathway (recently reviewed in Pavelic et al. 2007, Chitnis et al. 2008, Maki et al. 2010, Parella et al. 2010, Annunziata et al. 2011, Siddle et al. 2012, Holzenberger 2012)."
BMGC_PW0893,BMG_PW3294,,,"Inorganic (selenite, SeO3(2-); and selenate, SeO4(2-)) and organic (selenocysteine, Sec; and selenomethionine, SeMet) forms of selenium can introduced in the diet where they are transformed into the intermediate selenide (Se(2-)) through the trans-selenation pathway, selenocysteine lyase (SCLY), and cystathionine gamma-lyase (CTH)."
BMGC_PW0894,BMG_PW3295,,,"Ingested selenic acid (H2SeO4) and selenite (SeO3(2-)) are reduced to hydrogen selenide (H2Se) through a combination of actions involving bifunctional 3'-phosphoadenosine 5'-phosphosulfate synthase 1 and 2 (PAPSS1/2), PAPSe reductase (PAPSeR), and thioredoxin reductase 1 (TXNRD1)."
BMGC_PW0895,BMG_PW3297,,,"Selenocysteine, the 21st genetically encoded amino acid, is the major form of the antioxidant trace element selenium in the human body. In eukaryotes and archaea its synthesis proceeds through a phosphorylated intermediate in a tRNA-dependent fashion. The final step of selenocysteine formation is catalyzed by O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase (SEPSECS) that converts phosphoseryl-tRNA(Sec) to selenocysteinyl-tRNA(Sec)."
BMGC_PW0896,BMG_PW3298,,,"In response to receptor ligation, the tyrosine residues in DAP12's immunoreceptor tyrosine-based activation motif (ITAM) are phosphorylated by Src family kinases. These phosphotyrosines form the docking site for the protein tyrosine kinase SYK in myeloid cells and SYK and ZAP70 in NK cells. DAP12-bound SYK autophosphorylates and phosphorylates the scaffolding molecule LAT, recruiting the proximal signaling molecules phosphatidylinositol-3-OH kinase (PI3K), phospholipase-C gamma (PLC-gamma), GADS (GRB2-related adapter downstream of SHC), SLP76 (SH2 domain-containing leukocyte protein of 76 kDa), GRB2:SOS (Growth factor receptor-bound protein 2:Son of sevenless homolog 1) and VAV. All of these intermediate signalling molecules result in the recruitment and activation of kinases AKT, CBL (Casitas B-lineage lymphoma) and ERK (extracellular signal-regulated kinase), and rearrangement of the actin cytoskeleton (actin polymerization) finally leading to cellular activation. PLC-gamma generates the secondary messengers diacylglycerol (DAG) and inositol-1,4,5-trisphosphate (InsP3), leading to activation of protein kinase C (PKC) and calcium mobilization, respectively (Turnbull & Colonna 2007, Klesney-Tait et al. 2006)."
BMGC_PW0897,BMG_PW3299,,,"After transiting to the nucleus SREBPs (SREBP1A/1C/2, SREBFs) bind short sequences, sterol regulatory elements (SREs), in the promoters of target genes (reviewed in Eberle et al. 2004, Weber et al. 2004). SREBPs alone are relatively weak activators of transcription, with SREBP1C being significantly weaker than SREBP1A or SREBP2. In combination with other transcription factors such as SP1 and NF-Y the SREBPs are much stronger activators. SREBP1C seems to more specifically target genes involved in fatty acid synthesis while SREBP2 seems to target genes involved in cholesterol synthesis (Pai et al. 1998)."
BMGC_PW0898,BMG_PW3300,,,"After autophosphorylation the type 1 insulin-like growth factor receptor (IGF1R) binds and phosphorylates scaffold proteins, IRS1/2/4 and SHC1, which in turn bind effectors possessing enzymatic activity (recently reviewed in Pavelic et al. 2007, Chitnis et al. 2008, Maki et al. 2010, Parrella et al. 2010, and Siddle et al. 2012). IRS1/2/4 can bind both PI3K (via the p85 subunit of PI3K) and the GRB2:SOS complex. PI3K activates PKB (AKT, AKT1) signaling. GRB:SOS stimulates RAS to exchange GDP for GTP leading to activation of RAF and MAPK."
BMGC_PW0899,BMG_PW3301,,,"The phosphorylated type 1 insulin-like growth factor receptor phosphorylates IRS1, IRS2, IRS4 and possibly other IRS/DOK family members (reviewed in Pavelic et al. 2007, Chitnis et al. 2008, Maki et al. 2010, Parrella et al. 2010, Siddle et al. 2012). The phosphorylated IRS proteins serve as scaffolds that bind the effector molecules PI3K and GRB2:SOS. PI3K then activates PKB (AKT) signaling while GRB2:SOS activates RAS-RAF-MAPK signaling."
BMGC_PW0900,BMG_PW3302,,,"Phosphorylated IGF1R binds and phosphorylates SHC1 (reviewed in Pavelic et al. 2007, Chitnis et al. 2008, Maki et al. 2010, Parrella et al. 2010, Siddle et al. 2012). Phosphorylated SHC then binds GRB:SOS, which activates RAS-RAF-MAPK signaling."
BMGC_PW0901,BMG_PW3303,,,"The retinoid cycle (also referred to as the visual cycle) is the process by which the visual chromophore 11-cis-retinal (11cRAL) is released from light-activated opsins in the form all-trans-retinal and isomerized back to its 11-cis isomer ready for another photoisomerization reaction. This process involves oxidation, reduction and isomerization reactions and take place in the retinal pigment epithelium (RPE) and photoreceptor segments of the eye (von Lintig 2012, Blomhoff & Blomhoff 2006, von Lintig et al. 2010, D'Ambrosio et al. 2011). This section describes the retinoid cycle in rods during dark/twilight conditions."
BMGC_PW0902,BMG_PW3304,,"Fc epsilon RI-mediated signaling pathways in mast cells are initiated by the interaction of antigen (Ag) with IgE bound to the extracellular domain of the alpha chain of Fc epsilon RI. The activation pathways are regulated both positively and negatively by the interactions of numerous signaling molecules. Mast cells that are thus activated release preformed granules which contain biogenic amines (especially histamines) and proteoglycans (especially heparin). The activation of phospholipase A2 causes the release of membrane lipids followed by development of lipid mediators such as leukotrienes (LTC4, LTD4 and LTE4) and prostaglandins (especially PDG2). There is also secretion of cytokines, the most important of which are TNF-alpha, IL-4 and IL-5. These mediators and cytokines contribute to inflammatory responses.","Mast cells (MC) are distributed in tissues throughout the human body and have long been recognized as key cells of type I hypersensitivity reactions. They also play important roles in inflammatory and immediate allergic reactions. Activation through FCERI-bound antigen-specific IgE causes release of potent inflammatory mediators, such as histamine, proteases, chemotactic factors, cytokines and metabolites of arachidonic acid that act on the vasculature, smooth muscle, connective tissue, mucous glands and inflammatory cells (Borish & Joseph 1992, Amin 2012, Metcalfe et al. 1993). FCERI is a multimeric cell-surface receptor that binds the Fc fragment of IgE with high affinity. On mast cells and basophils FCERI exists as a tetrameric complex consisting of one alpha-chain, one beta-chain, and two disulfide-bonded gamma-chains, and on dendritic cells, Langerhans cells, macrophages, and eosinophils it exists as a trimeric complex with one alpha-chain and two disulfide-bonded gamma-chains (Wu 2011, Kraft & Kinet 2007). FCERI signaling in mast cells includes a network of signaling molecules and adaptor proteins. These molecules coordinate ultimately leading to effects on degranulation, eicosanoid production, and cytokine and chemokine production and cell migration and adhesion, growth and survival. The first step in FCERI signaling is the phosphorylation of the tyrosine residues in the ITAM of both the beta and the gamma subunits of the FCERI by LYN, which is bound to the FCERI beta-chain. The phosphorylated ITAM then recruits the protein tyrosine kinase SYK (spleen tyrosine kinase) which then phosphorylates the adaptor protein LAT. Phosphorylated LAT (linker for activation of T cells) acts as a scaffolding protein and recruits other cytosolic adaptor molecules GRB2 (growth-factor-receptor-bound protein 2), GADS (GRB2-related adaptor protein), SHC (SRC homology 2 (SH2)-domain-containing transforming protein C) and SLP76 (SH2-domain-containing leukocyte protein of 76 kDa), as well as the exchange factors and adaptor molecules VAV and SOS (son of sevenless homologue), and the signalling enzyme phospholipase C gamma1 (PLC-gamma1). Tyrosoine phosphorylation of enzymes and adaptors, including VAV, SHC GRB2 and SOS stimulate small GTPases such as RAC, RAS and RAF. These pathways lead to activation of the ERK, JNK and p38 MAP kinases, histamine release and cytokine production. FCERI activation also triggers the phosphorylation of PLC-gamma which upon membrane localisation hydrolyse PIP2 to form IP3 and 1,2-diacylglycerol (DAG) - second messengers that release Ca2+ from internal stores and activate PKC, respectively. Degranulation or histamine release follows the activation of PLC-gamma and protein kinase C (PKC) and the increased mobilization of calcium (Ca2+). Receptor aggregation also results in the phosphorylation of adaptor protein NTAL/LAT2 which then recruits GAB2. PI3K associates with phosphorylated GAB2 and catalyses the formation of PIP3 in the membrane, which attracts many PH domain proteins like BTK, PLC-gamma, AKT and PDK. PI3K mediated activation of AKT then regulate the mast cell proliferation, development and survival (Gu et al. 2001)."
BMGC_PW0903,BMG_PW3305,,,"The activity of MASTL, also known as the Greatwall kinase (GWL), is necessary for the entry and progression of mitosis. MASTL is activated by phosphorylation of several key residues during mitotic entry. Phosphorylation on the serine residue S875 (S883 in Xenopus), likely through autophosphorylation (Blake-Hodek et al. 2012) appears to be critical (Vigneron et al. 2011). Several other sites, including putative CDK1 targets T194, T207 and T741, contribute to the full activation of MASTL (Yu et al. 2006, Blake-Hodek et al. 2012). Other kinases, such as PLK1 (Vigneron et al. 2011) and other MASTL phosphorylation sites may also be functionally important (Yu et al. 2006, Blake-Hodek et al. 2012). Activated MASTL phosphorylates ARPP19 and ENSA on serines S62 and S67, respectively, enabling them to bind to and inhibit the phosphatase activity of PP2A complexed with the regulatory subunit PPP2R2D (B55-delta). Inhibition of PP2A-PPP2R2D activity by ARPP19 or ENSA prevents dephosphorylation of CDK1 targets, hence allowing entry and maintenance of mitosis (Mochida et al. 2010, Gharbi-Ayachi et al. 2010, Burgess et al. 2010)."
BMGC_PW0904,BMG_PW3307,,,"While sister chromatids resolve in prometaphase, separating along chromosomal arms, the cohesion of sister centromeres persists until anaphase. At the anaphase onset, the anaphase promoting complex/cyclosome (APC/C) ubiquitinates PTTG1 (securin), targeting it for degradation (Hagting et al. 2002). PTTG1 acts as an inhibitor of ESPL1 (known as separin i.e. separase). Hence, PTTG1 removal initiated by APC/C, enables ESPL1 to become catalytically active (Zou et al. 1999, Waizenegger et al. 2002). ESPL1 undergoes autoleavage (Waizenegger et al. 2002) and also cleaves RAD21 subunit of centromeric cohesin (Hauf et al. 2001). RAD21 cleavage promotes dissociation of cohesin complexes from sister centromeres, leading to separation of sister chromatids. Subsequent movement of sister chromatids to opposite poles of the mitotic spindle segregates replicated chromosomes to two daughter cells (Waizenegger et al. 2000, Hauf et al. 2001, Waizenegger et al. 2002)."
BMGC_PW0905,BMG_PW3308,,,"The cohesin complex loads onto chromatin in telophase, but its association with chromatin remains transient, dynamic until the S-phase of the cell cycle, presumably because the cohesin-bound NIPBL:MAU2 (SCC2:SCC4) complex promotes chromatin loading, while cohesin-bound WAPAL promotes dissociation from chromatin. Stable binding of cohesin complexes to chromatin, measured by a mean residence time on chromatin, is triggered by DNA replication in S-phase (Gerlich et al. 2006), consistent with establishment of sister chromatid cohesion. In S-phase, acetyltransferases ESCO1 and ESCO2 acetylate the SMC3 cohesin subunit (Hou and Zou 2005, Zhang et al. 2008, Nishiyama et al. 2010, Whelan et al. 2012). The acetylation of SMC3, in addition to DNA replication and the presence of PDS5 on cohesin, facilitates the recruitment of CDCA5 (Sororin) to cohesin complexes, an essential step in the establishment of sister chromatid cohesion in mammalian cells (Rankin et al. 2005, Nishiyama et al. 2010). CDCA5 (Sororin) displaces WAPAL from PDS5, thus preventing WAPAL to interfere with the establishment of sister chromatid cohesion (Nishiyama et al. 2010). The establishment and temporal regulation of sister chromatid cohesion is necessary for equal segregation of replicated chromosomes to daughter cells."
BMGC_PW0906,BMG_PW3309,,,"In mitotic telophase, as chromosomes decondense, cohesin complex associated with PDS5 (PDS5A and PDS5B) and WAPAL (WAPL) proteins is loaded onto chromatin (Shintomi and Hirano, 2009, Kueng et al. 2006, Gandhi et al. 2006, Chan et al. 2012). Cohesin loading is facilitated by the complex of NIPBL (SCC2) and MAU2 (SCC4) proteins, which constitute an evolutionarily conserved cohesin loading complex. MAU2 depletion in HeLa cells results in 2-3-fold reduction in the amount of cohesin in the chromatin fraction (Watrin et al. 2006). NIPBL mutations are the cause of the Cornelia de Lange syndrome, a dominantly inherited disorder characterized by facial malformations, limb defects, and growth and cognitive retardation (Tonkin et al. 2004). Cornelia de Lange syndrome can also be caused by mutations in cohesin subunits SMC1A (Musio et al. 2006, Borck et al. 2007, Deardorff et al. 2007, Pie et al. 2010) and SMC3 (Deardorff et al. 2007)."
BMGC_PW0907,BMG_PW3311,,,"The photoreceptor cascade starts with light isomerization of 11-cis-retinal (11cRAL) of rhodopsin (RHO) to all-trans-retinal (atRAL), inducing a conformational change in RHO to the active, metarhodopsin II (MII) state. MII activates the G protein transducin (Gt) that in turn activates phosphodiesterase 6 (PDE6). Consequently, there is a fall in the intracellular concentration of cGMP that closes cGMP-dependent cation channels (CNG channels) and hyperpolarizes the rod. This has the effect of reducing or stopping glutamate release from synaptic vesicles thus signalling to the surrounding cells how many photons were absorbed (Burns & Pugh 2010, Korenbrot 2012, Pugh & Lamb 1993)."
BMGC_PW0908,BMG_PW3312,,,"The resolution of sister chromatids in mitotic prometaphase involves removal of cohesin complexes from chromosomal arms, with preservation of cohesion at centromeres (Losada et al. 1998, Hauf et al. 2001, Hauf et al. 2005). CDK1-mediated phosphorylation of cohesin-bound CDCA5 (Sororin) at threonine T159 provides a docking site for PLK1, enabling PLK1-mediated phosphorylation of cohesin subunits STAG2 (SA2) and RAD21 (Hauf et al. 2005, Dreier et al. 2011, Zhang et al. 2011). Further phosphorylation of CDCA5 by CDK1 results in dissociation of CDCA5 from cohesin complex, which restores the activity of WAPAL in removing STAG2-phosphorylated cohesin from chromosomal arms (Hauf et al. 2005, Gandhi et al. 2006, Kueng et al. 2006, Shintomi and Hirano 2006, Nishiyama et al. 2010, Zhang et al. 2011). At centromeres, kinetochore proteins shugoshins (SGOL1 and SGOL2) enable PP2A-B56 (also a kinetochore constituent) to dephosphorylate the STAG2 subunit of centromeric cohesin. Dephosphorylation of STAG2 enables maintenance of centromeric cohesion, thus preventing separation of sister chromatids until anaphase (Salic et al. 2004, Kitajima et al. 2004, Kitajima et al. 2005, Kitajima et al. 2006)."
BMGC_PW0909,BMG_PW3313,,,"The condensin I complex is evolutionarily conserved and consists of five subunits: two SMC (structural maintenance of chromosomes) family subunits, SMC2 and SMC4, and three non-SMC subunits, NCAPD2, NCAPH and NCAPG. The stoichiometry of the complex is 1:1:1:1:1 (Hirano and Mitchinson 1994, Hirano et al. 1997, Kimura et al. 2001). SMC2 and SMC4 subunits, shared between condensin I and condensin II, are DNA-dependent ATPases, and condensins are able to introduce positive supercoils into DNA in an ATP-dependent manner (Kimura and Hirano 1997). Protein levels of condensin subunits are constant during the cell cycle, however condensins are enriched on mitotic chromosomes. Four of the five subunits, SMC4, NCAPD2, NCAPG and NCAPH, are phosphorylated in both mitotic and interphase HeLa cells, but on different sites (Takemoto et al. 2004). CDK1 (CDC2) in complex with CCNB (cyclin B) phosphorylates NCAPD2, NCAPG and NCAPH in mitosis (Kimura et al. 1998, Kimura et al. 2001, Takemoto et al. 2006, Murphy et al. 2008), but other mitotic kinases, such as PLK1 (St-Pierre et al. 2009), and other post-translational modifications, such as acetylation, may also be involved (reviewed by Bazile et al. 2010). Global proteomic analysis of human cell lines has identified N6-acetylation of lysine residues in condensin subunits SMC2, SMC4 and NCAPH (Choudhary et al. 2009). Another high throughput proteomic study showed that condensin I subunits NCAPD2 and NCAPH are phosphorylated upon DNA damage, probably by ATM or ATR kinase (Matsuoka et al. 2007). As condensin I is cytosolic, it gains access to chromosomes only after the nuclear envelope breakdown at the start of prometaphase (Ono et al. 2004). Condensin I, activated by CDK1-mediated phosphorylation, promotes hypercondensation of chromosomes that were condensed in prophase through the action of condensin II (Hirota et al. 2004). AURKB may also regulate association of condensin I complex with chromatin (Lipp et al. 2007). Protein phosphatase PP2A acts independently of its catalytic activity to target condensin II complex to chromatin, but does not interact with condensin I (Takemoto et al. 2009). Full activation of condensin I requires dephosphorylation of sites modified by CK2 during interphase (Takemoto et al. 2006). Besides being essential for chromosome condensation in mitosis, condensin I may also contribute to cohesin removal from chromosome arms in prometaphase, but the exact mechanism is not known (Hirota et al. 2004)."
BMGC_PW0910,BMG_PW3314,,,"To terminate the single photon response and restore the system to its basal state, the three activated intermediates in phototransduction, rhodopsin (MII), transducin alpha subunit with GTP bound (GNAT1-GTP) and phosphodiesterase 6 (PDE6) all need to be efficiently deactivated. In addition, the cGMP concentrations must be restored to support reopening of the CNG channels. This section describes the inactivation and recovery events of the activated intermediates involved in phototransduction (Burns & Pugh 2010, Korenbrot 2012)."
BMGC_PW0911,BMG_PW3316,,,"Oxidative stress, caused by increased concentration of reactive oxygen species (ROS) in the cell, can happen as a consequence of mitochondrial dysfunction induced by the oncogenic RAS (Moiseeva et al. 2009) or independent of oncogenic signaling. Prolonged exposure to interferon-beta (IFNB, IFN-beta) also results in ROS increase (Moiseeva et al. 2006). ROS oxidize thioredoxin (TXN), which causes TXN to dissociate from the N-terminus of MAP3K5 (ASK1), enabling MAP3K5 to become catalytically active (Saitoh et al. 1998). ROS also stimulate expression of Ste20 family kinases MINK1 (MINK) and TNIK through an unknown mechanism, and MINK1 and TNIK positively regulate MAP3K5 activation (Nicke et al. 2005). MAP3K5 phosphorylates and activates MAP2K3 (MKK3) and MAP2K6 (MKK6) (Ichijo et al. 1997, Takekawa et al. 2005), which act as p38 MAPK kinases, as well as MAP2K4 (SEK1) (Ichijo et al. 1997, Matsuura et al. 2002), which, together with MAP2K7 (MKK7), acts as a JNK kinase. MKK3 and MKK6 phosphorylate and activate p38 MAPK alpha (MAPK14) and beta (MAPK11) (Raingeaud et al. 1996), enabling p38 MAPKs to phosphorylate and activate MAPKAPK2 (MK2) and MAPKAPK3 (MK3) (Ben-Levy et al. 1995, Clifton et al. 1996, McLaughlin et al. 1996, Sithanandam et al. 1996, Meng et al. 2002, Lukas et al. 2004, White et al. 2007), as well as MAPKAPK5 (PRAK) (New et al. 1998 and 2003, Sun et al. 2007). Phosphorylation of JNKs (MAPK8, MAPK9 and MAPK10) by MAP3K5-activated MAP2K4 (Deacon and Blank 1997, Fleming et al. 2000) allows JNKs to migrate to the nucleus (Mizukami et al. 1997) where they phosphorylate JUN. Phosphorylated JUN binds FOS phosphorylated by ERK1 or ERK2, downstream of activated RAS (Okazaki and Sagata 1995, Murphy et al. 2002), forming the activated protein 1 (AP-1) complex (FOS:JUN heterodimer) (Glover and Harrison 1995, Ainbinder et al. 1997). Activation of p38 MAPKs and JNKs downstream of MAP3K5 (ASK1) ultimately converges on transcriptional regulation of CDKN2A locus. In dividing cells, nucleosomes bound to the CDKN2A locus are trimethylated on lysine residue 28 of histone H3 (HIST1H3A) by the Polycomb repressor complex 2 (PRC2), creating the H3K27Me3 (Me3K-28-HIST1H3A) mark (Bracken et al. 2007, Kotake et al. 2007). The expression of Polycomb constituents of PRC2 (Kuzmichev et al. 2002) - EZH2, EED and SUZ12 - and thereby formation of the PRC2, is positively regulated in growing cells by E2F1, E2F2 and E2F3 (Weinmann et al. 2001, Bracken et al. 2003). H3K27Me3 mark serves as a docking site for the Polycomb repressor complex 1 (PRC1) that contains BMI1 (PCGF4) and is therefore named PRC1.4, leading to the repression of transcription of p16INK4A and p14ARF from the CDKN2A locus, where PCR1.4 mediated repression of p14ARF transcription in humans may be context dependent (Voncken et al. 2005, Dietrich et al. 2007, Agherbi et al. 2009, Gao et al. 2012). MAPKAPK2 and MAPKAPK3, activated downstream of the MAP3K5-p38 MAPK cascade, phosphorylate BMI1 of the PRC1.4 complex, leading to dissociation of PRC1.4 complex from the CDKN2A locus and upregulation of p14ARF transcription (Voncken et al. 2005). AP-1 transcription factor, formed as a result of MAP3K5-JNK signaling, as well as RAS signaling, binds the promoter of KDM6B (JMJD3) gene and stimulates KDM6B expression. KDM6B is a histone demethylase that removes H3K27Me3 mark i.e. demethylates lysine K28 of HIST1H3A, thereby preventing PRC1.4 binding to the CDKN2A locus and allowing transcription of p16INK4A (Agger et al. 2009, Barradas et al. 2009, Lin et al. 2012). p16INK4A inhibits phosphorylation-mediated inactivation of RB family members by CDK4 and CDK6, leading to cell cycle arrest (Serrano et al. 1993). p14ARF inhibits MDM2-mediated degradation of TP53 (p53) (Zhang et al. 1998), which also contributes to cell cycle arrest in cells undergoing oxidative stress. In addition, phosphorylation of TP53 by MAPKAPK5 (PRAK) activated downstream of MAP3K5-p38 MAPK signaling, activates TP53 and contributes to cellular senescence (Sun et al. 2007)."
BMGC_PW0912,BMG_PW3317,,,"The culture medium of senescent cells in enriched in secreted proteins when compared with the culture medium of quiescent i.e. presenescent cells and these secreted proteins constitute the so-called senescence-associated secretory phenotype (SASP), also known as the senescence messaging secretome (SMS). SASP components include inflammatory and immune-modulatory cytokines (e.g. IL6 and IL8), growth factors (e.g. IGFBPs), shed cell surface molecules (e.g. TNF receptors) and survival factors. While the SASP exhibits a wide ranging profile, it is not significantly affected by the type of senescence trigger (oncogenic signalling, oxidative stress or DNA damage) or the cell type (epithelial vs. mesenchymal) (Coppe et al. 2008). However, as both oxidative stress and oncogenic signaling induce DNA damage, the persistent DNA damage may be a deciding SASP initiator (Rodier et al. 2009). SASP components function in an autocrine manner, reinforcing the senescent phenotype (Kuilman et al. 2008, Acosta et al. 2008), and in the paracrine manner, where they may promote epithelial-to-mesenchymal transition (EMT) and malignancy in the nearby premalignant or malignant cells (Coppe et al. 2008). Interleukin-1-alpha (IL1A), a minor SASP component whose transcription is stimulated by the AP-1 (FOS:JUN) complex (Bailly et al. 1996), can cause paracrine senescence through IL1 and inflammasome signaling (Acosta et al. 2013). Here, transcriptional regulatory processes that mediate the SASP are annotated. DNA damage triggers ATM-mediated activation of TP53, resulting in the increased level of CDKN1A (p21). CDKN1A-mediated inhibition of CDK2 prevents phosphorylation and inactivation of the Cdh1:APC/C complex, allowing it to ubiquitinate and target for degradation EHMT1 and EHMT2 histone methyltransferases. As EHMT1 and EHMT2 methylate and silence the promoters of IL6 and IL8 genes, degradation of these methyltransferases relieves the inhibition of IL6 and IL8 transcription (Takahashi et al. 2012). In addition, oncogenic RAS signaling activates the CEBPB (C/EBP-beta) transcription factor (Nakajima et al. 1993, Lee et al. 2010), which binds promoters of IL6 and IL8 genes and stimulates their transcription (Kuilman et al. 2008, Lee et al. 2010). CEBPB also stimulates the transcription of CDKN2B (p15-INK4B), reinforcing the cell cycle arrest (Kuilman et al. 2008). CEBPB transcription factor has three isoforms, due to three alternative translation start sites. The CEBPB-1 isoform (C/EBP-beta-1) seems to be exclusively involved in growth arrest and senescence, while the CEBPB-2 (C/EBP-beta-2) isoform may promote cellular proliferation (Atwood and Sealy 2010 and 2011). IL6 signaling stimulates the transcription of CEBPB (Niehof et al. 2001), creating a positive feedback loop (Kuilman et al. 2009, Lee et al. 2010). NF-kappa-B transcription factor is also activated in senescence (Chien et al. 2011) through IL1 signaling (Jimi et al. 1996, Hartupee et al. 2008, Orjalo et al. 2009). NF-kappa-B binds IL6 and IL8 promoters and cooperates with CEBPB transcription factor in the induction of IL6 and IL8 transcription (Matsusaka et al. 1993, Acosta et al. 2008). Besides IL6 and IL8, their receptors are also upregulated in senescence (Kuilman et al. 2008, Acosta et al. 2008) and IL6 and IL8 may be master regulators of the SASP. IGFBP7 is also an SASP component that is upregulated in response to oncogenic RAS-RAF-MAPK signaling and oxidative stress, as its transcription is directly stimulated by the AP-1 (JUN:FOS) transcription factor. IGFBP7 negatively regulates RAS-RAF (BRAF)-MAPK signaling and is important for the establishment of senescence in melanocytes (Wajapeyee et al. 2008). Please refer to Young and Narita 2009 for a recent review."
BMGC_PW0913,BMG_PW3318,,,"The process of DNA damage/telomere stress induced senescence culminates in the formation of senescence associated heterochromatin foci (SAHF). These foci represent facultative heterochromatin that is formed in senescent cells. They contribute to the repression of proliferation promoting genes and play an important role in the permanent cell cycle exit that characterizes senescence (Narita et al. 2003 and 2006). SAHF appear as compacted, punctate DAPI stained foci of DNA. Each chromosome is condensed into a single SAH focus, with telomeric and centromeric chromatin located predominantly at its periphery (Funayama et al. 2006, Zhang et al. 2007). An evolutionarily conserved protein complex of HIRA, ASF1A, UBN1 and CABIN1 plays a crucial role in the SAHF formation. As cells approach senescence, HIRA, ASF1A, UBN1 and CABIN1 accumulate at the PML bodies (Zhang et al. 2005, Banumathy et al. 2009, Rai et al. 2011). PML bodies are punctate nuclear structures that contain PML protein and numerous other proteins and are proposed to be the sites of assembly of macromolecular regulatory complexes and protein modification (Fogal et al. 2000, Guo et al. 2000, Pearson et al. 2000). Recruitment of HIRA to PML bodies coincides with altered chromatin structure and deposition of macroH2A histone H2A variant onto chromatin. As cells become senescent, HIRA, ASF1A, UBN1 and CABIN1 relocate from PML bodies to SAHF. HIRA accumulation at PML bodies is RB1 and TP53 independent, but may require phosphorylation of HIRA serine S697 by GSK3B (Ye, Zerlanko, Kennedy et al. 2007). SAHF formation itself, however, requires functional RB1 and TP53 pathways (Ye, Zerlanko, Zhang et al. 2007). SAHF contain H3K9Me mark, characteristic of trancriptionally silent chromatin, and HP1, marcoH2A histone H2A variant and HMGA proteins are also components of SAHF (Narita et al. 2006), besides the HIRA:ASF1A:UBN1:CABIN1 complex. A yet unidentified H3K9Me histone methyltransferase may be recruited to SAHF by UBN1 (Banumathy et al. 2009). One of the functions of the HIRA:ASF1A:UBN1:CABIN1 complex is to deposit histone H3.3. variant to chromatin, which influences gene expression (Zhang et al. 2007, Rai et al. 2011). Further studies are needed to fully elucidate the mechanism of SAHF formation and mechanism by which SAHF promote cell senescence."
BMGC_PW0914,BMG_PW3319,,,"Reactive oxygen species (ROS), whose concentration increases in senescent cells due to oncogenic RAS-induced mitochondrial dysfunction (Moiseeva et al. 2009) or due to environmental stress, cause DNA damage in the form of double strand breaks (DSBs) (Yu and Anderson 1997). In addition, persistent cell division fueled by oncogenic signaling leads to replicative exhaustion, manifested in critically short telomeres (Harley et al. 1990, Hastie et al. 1990). Shortened telomeres are no longer able to bind the protective shelterin complex (Smogorzewska et al. 2000, de Lange 2005) and are recognized as damaged DNA. The evolutionarily conserved MRN complex, consisting of MRE11A (MRE11), RAD50 and NBN (NBS1) subunits, binds DSBs (Lee and Paull 2005) and shortened telomeres that are no longer protected by shelterin (Wu et al. 2007). Once bound to the DNA, the MRN complex recruits and activates ATM kinase (Lee and Paull 2005, Wu et al. 2007), leading to phosphorylation of ATM targets, including TP53 (p53) (Banin et al. 1998, Canman et al. 1998, Khanna et al. 1998). TP53, phosphorylated on serine S15 by ATM, binds the CDKN1A (also known as p21, CIP1 or WAF1) promoter and induces CDKN1A transcription (El-Deiry et al. 1993, Karlseder et al. 1999). CDKN1A inhibits the activity of CDK2, leading to G1/S cell cycle arrest (Harper et al. 1993, El-Deiry et al. 1993). SMURF2 is upregulated in response to telomere attrition in human fibroblasts and induces senecscent phenotype through RB1 and TP53, independently of its role in TGF-beta-1 signaling (Zhang and Cohen 2004). The exact mechanism of SMURF2 involvement is senescence has not been elucidated."
BMGC_PW0915,BMG_PW3320,,,"TLR3 and -4 trigger TRIF-dependent programmed cell death in various human and mouse cells (Kalai M et al. 2002; Han KJ et al. 2004; Kaiser WJ and Offermann MK 2005; Estornes Y et al. 2012; He S et al. 2011). Apoptosis is a prevalent form of programmed cell death and is mediated by the activation of a set of caspases. In addition to apoptosis, TLR3/TLR4 activation induces RIP3-dependent necroptosis. These two programmed cell-death pathways may suppress each other. When the caspase activity is impaired or inhibited, certain cell types switch the apoptotic death program to necroptosis in response to various stimuli (TNF, Fas, viral infection and other stress stimuli) (Kalai M et al. 2002; Weber A et al. 2010; Feoktistova M et al. 2011, Tenev et al 2011)."
BMGC_PW0916,BMG_PW3321,,,"Iron-sulfur clusters containing 4 atoms of iron and 4 atoms of sulfur (4Fe-4S clusters) are assembled in the cytosol on a heterotetrameric scaffold composed of NUBP2 and NUBP1 subunits (reviewed in Lill et al. 2012, Rouault et al. 2012, Sharma et al. 2010, Lill and Muhlenhoff 2006). The sources of iron and sulfur are uncertain but the process requires a sulfur-containing compound exported from mitochondria via ABCB7 (ABC7). Newly synthesized 4Fe-4S are transferred to apoproteins such as XPD and POLD1 via the CIA targeting complex, composed of NARFL, CIAO1, FAM96B, and MMS19."
BMGC_PW0917,BMG_PW3322,,,"The kinase activity of PLK1 is required for cell cycle progression as PLK1 phosphorylates and regulates a number of cellular proteins during mitosis. Centrosomic AURKA (Aurora A kinase), catalytically activated through AJUBA facilitated autophosphorylation on threonine residue T288 at G2/M transition (Hirota et al. 2003), activates PLK1 on centrosomes by phosphorylating threonine residue T210 of PLK1, critical for PLK1 activity (Jang et al. 2002), in the presence of BORA (Macurek et al. 2008, Seki et al. 2008). Once activated, PLK1 phosphorylates BORA and targets it for ubiquitination mediated degradation by SCF-beta-TrCP ubiquitin ligases. Degradation of BORA is thought to allow PLK1 to interact with other substrates (Seki, Coppinger, Du et al. 2008, Seki et al. 2008). The interaction of PLK1 with OPTN (optineurin) provides a negative-feedback mechanism for regulation of PLK1 activity. Phosphorylated PLK1 binds and phosphorylates OPTN associated with the Golgi membrane GTPase RAB8, promoting dissociation of OPTN from Golgi and translocation of OPTN to the nucleus. Phosphorylated OPTN facilitates the mitotic phosphorylation of the myosin phosphatase subunit PPP1R12A (MYPT1) and myosin phosphatase activation (Kachaner et al. 2012). The myosin phosphatase complex dephosphorylates threonine residue T210 of PLK1 and inactivates PLK1 (Yamashiro et al. 2008)."
BMGC_PW0918,BMG_PW3323,,,"NOTCH1 PEST domain mutations are frequently found in T-cell acute lymphoblastic leukemia (T-ALL). PEST domain mutations interfere with ubiquitination-mediated NOTCH1 downregulation and result in prolonged half-life of the intracellular NOTCH1 fragment, NICD1, and increased NICD1 transcriptional activity (Weng et al. 2004, Thompson et al. 2007, O'Neil et al. 2007)."
BMGC_PW0919,BMG_PW3324,,,"Human NOTCH1 was cloned as a chromosome 9 gene, translocated to the T-cell beta receptor (TCBR) promoter on chromosome 7 in T-cell acute lymphoblastic leukemia (T-ALL) (Ellisen et al. 1991). This translocation, present in only a small percentage of T-ALL patients, results in the overexpression of a truncated NOTCH1 receptor, which lacks almost the entire extracellular domain, in T lymphocytes. Oncogenic NOTCH1 mutations were subsequently found to be present in >50% of T-ALL patients, with hotspots in the heterodimerization domain (HD domain) and PEST domain of NOTCH1 (Weng et al. 2004). Normal NOTCH1 becomes activated by binding DLL (DLL1 or DLL4) or JAG (JAG1 or JAG2) ligands expressed on the surface of a neighboring cell, which leads to proteolytic cleavage of NOTCH1 by ADAM10/17 and gamma-secretase, and release of the NOTCH1 intracellular domain (NICD1) which regulates expression of genes that play important roles in the development of T lymphocytes (Washburn et al. 1997. Radtke et al. 1999, Maillard et al. 2004, Sambandam et al. 2005, Tan et al. 2005). Mutations in the HD domain, responsible for association of NOTCH1 extracellular and transmembrane regions after furin-mediated cleavage of NOTCH1 precursor, as well as the truncation of the NOTCH1 extracellular domain by the rare T-ALL translocation, enable constitutive production of NICD1, in the absence of ligand binding (Malecki et al. 2006, Ellisen et al. 1991). Mutations in the NOTCH1 PEST domain interfere with FBXW7 (FBW7)-mediated ubiquitination and degradation of NICD1, resulting in prolonged half-life and increased transcriptional activity of NICD1, which promotes growth and division of T-lymphocytes (Weng et al. 2004, Thompson et al. 2007, O'Neil et al. 2007). Mutations in the HD domain and PEST domain of NOTCH1 are frequently found in cis in T-ALL. While HD mutations alone result in up to ~10-fold increase in NOTCH1 transcriptional activity and PEST domain mutations alone result in up to ~2-fold increase in NOTCH1 transcriptional activity, in cis mutations of HD and PEST domains act synergistically, increasing NOTCH1 transcriptional activity up to ~40-fold (Weng et al. 2004). FBXW7 (FBW7), a component of the SCF (SKP1, CUL1, and F-box protein) ubiquitin ligase complex SCF-FBW7 involved in the degradation of NOTCH1 (Oberg et al. 2001, Wu et al. 2001, Fryer et al. 2004), is subject to loss of function mutations in T-ALL (Akhoondi et al. 2007, Thompson et al. 2007, O'Neil et al. 2007) which are mutually exclusive with NOTCH1 PEST domain mutations (Thompson et al. 2007, O'Neil et al. 2007). Although gamma-secretase inhibitors (GSIs) are successfully used in vitro to inhibit NOTCH1 signaling in T-ALL cell lines, the gamma-secretase complex has many other substrates besides NOTCH. The specificity of GSIs is therefore limited and, as they are not considered to be particularly promising drugs for the clinical treatment of T-ALL (reviewed by Purow, 2012), they have not been annotated. For a recent review of NOTCH1 signaling in cancer, please refer to Grabher et al. 2006."
BMGC_PW0920,BMG_PW3325,,,"FBXW7 (FBW7) is a component of the SCF (SKP1, CUL1, and F-box protein) ubiquitin ligase complex SCF-FBW7 which is involved in the degradation of NOTCH1 (Oberg et al. 2001, Wu et al. 2001, Fryer et al. 2004). Loss of function mutations in FBXW7 are frequently found in T-cell acute lymphoblastic leukemia (Akhoondi et al. 2007, Thompson et al. 2007, O'Neil et al. 2007) and are mutually exclusive with NOTCH1 PEST domain mutations (Thompson et al. 2007, O'Neil et al. 2007)."
BMGC_PW0921,BMG_PW3326,,,"As NOTCH1 PEST domain is intracellular, NOTCH1 PEST domain mutants are expected to behave as the wild-type NOTCH1 with respect to ligand binding and proteolytic cleavage mediated activation of signaling. However, once the NICD1 fragment of NOTCH1 is released, PEST domain mutations prolong its half-life and transcriptional activity through interference with FBXW7 (FBW7)-mediated ubiquitination and degradation of NICD1 (Weng et al. 2004, Thompson et al. 2007, O'Neil et al. 2007). All NOTCH1 PEST domain mutants annotated here (NOTCH1 Q2395*, NOTCH1 Q2440*, NOTCH1 P2474Afs*4 and NOTCH1 P2514Rfs*4) either have a truncated PEST domain or lack the PEST domain completely."
BMGC_PW0922,BMG_PW3327,,,"Loss of function mutations found in FBXW7 in T-cell acute lymphoblastic leukemia are predominantly dominant negative missense mutations that target one of the three highly conserved arginine residues in the WD repeats of FBXW7 (Thompson et al. 2007, O'Neil et al. 2007). These three arginine residues are part of the FBXW7 substrate binding pocket and each one of them contacts the phosphorylated threonine residue in the conserved substrate phosphodegron region (Orlicky et al. 2003). Specifically, FBXW7 interacts with the PEST domain of NOTCH1 upon phosphorylation of the PEST domain by CDK8 (Fryer et al. 2004). FBXW7 mutants are therefore unable to bind and promote ubiquitination of the NOTCH1 intracellular domain (NICD1), leading to prolonged NICD1 transcriptional activity (Thompson et al. 2007, O'Neil et al. 2007)."
BMGC_PW0923,BMG_PW3328,,,"Acetylcholine neurotransmitter release cycle involves synthesis of acetylecholine, loading of synaptic vesicles, docking and priming of the acetyl choline loaded synaptic vesicles and then release of acetylcholine. This cycle occurs in neurons of central nervous system (CNS), peripheral, autonomic and somatic nervous system. In the CNS, the acetylcholine is released by the presynaptic neurons into the synaptic cleft where the released acetylcholine is accessible to acetylcholine receptors located on the postsynaptic neurons."
BMGC_PW0924,BMG_PW3329,,,"Caspase-mediated cleavage of a number of proteins in the cortical actin network ( ) microfilament system and others involved in maintenance of the cytoskeletal architecture (vimentin, or Gas2 and plectin) may directly contribute to apoptotic changes in cell shape."
BMGC_PW0925,BMG_PW3330,,,"Human NOTCH1 was cloned as a chromosome 9 gene, translocated to the T-cell beta receptor (TCBR) promoter on chromosome 7 in T-cell acute lymphoblastic leukemia (T-ALL) (Ellisen et al. 1991). The translocated gene was found to be homologous to Drosophila Notch, and was initially named TAN-1 (translocation-associated Notch homolog). Although the translocation t(7;9)(q34;q34.3) is present in a small percentage of T-ALL patients, the mutant protein is highly oncogenic and its overexpression causes T-ALL-like illness in mice (Pear et al. 1996)."
BMGC_PW0926,BMG_PW3331,,,"NOTCH1 t(7;9)(NOTCH1:M1580_K2555) mutant is expressed in a small subset of T-cell acute lymphoblastic leukemia (T-ALL) patients. This mutant protein results from a translocation that joins a portion of intron 24 of the NOTCH1 gene to the promoter sequence of T-cell receptor beta (TCRB), leading to overexpression of a truncated NOTCH1 protein in T-cells and their precursors. The truncated NOTCH1 contains amino acids 1580 to 2555 of the wild-type NOTCH1, lacking almost the entire extracellular domain, including EGF and LIN12 repeats (Ellisen et al. 1991). As EGF repeats are needed for NOTCH1 interaction with its ligands (DLL1, DLL4, JAG1, JAG2), the mutant NOTCH1 t(7;9)(NOTCH1:M1580_K2555) does not bind a ligand. The constitutive activity of NOTCH1 t(7;9)(NOTCH1:M1580_K2555) is based on its constitutive proteolytic processing into NOTCH1 intracellular domain (NICD1) by ADAM10/17 protease and gamma-secretase complex, as proteolytic cleavage sites are exposed in the absence of ligand binding in the mutant protein. Constitutively produced NICD1 accumulates in the nucleus, leading to aberrant activation of NOTCH1 target genes which play important roles in the development of T lymphocytes (Washburn et al. 1997. Radtke et al. 1999, Maillard et al. 2004, Sambandam et al. 2005, Tan et al. 2005). Infection of bone marrow cells with recombinant retroviruses that code for truncated NOTCH1 that resembles t(7;9)(NOTCH1:M1580_K2555) resulted in T-ALL-like illness in a portion of mice that received the infected bone-marrow transplant, with all tumors overexpressing truncated forms of NOTCH1 (Pear et al. 1996)."
BMGC_PW0927,BMG_PW3332,,,"Ion channels that mediate sensations such as pain, warmth, cold, taste pressure and vision. Channels that mediate these sensations include acid-sensing ion channels (ASICs) (Wang & Xu 2011, Qadri et al. 2012, Deval et al. 2010) and the transient receptor potential channels (TRPCs) (Takahashi et al. 2012, Numata et al. 2011 in ""TRP Channels"" Zhu, MX editor, CRC Press, 2011, Ramsey et al. 2006, Montell 2005). Many channels are sensitive to changes in calcium (Ca2+) levels, both inside and outside the cell. Examples are protein tweety homologs 2 and 3 (TTYH2, 3) (Suzuki 2006), bestrophins 1-4 (BEST1-4) (Sun et al. 2002, Tsunenari et al. 2003, Kunzelmann et al. 2009, Hartzell et al. 2008) and ryanodine receptor tetramers (RYRs) (Beard et al. 2009)."
BMGC_PW0928,BMG_PW3333,,,"During the development process cell migration and adhesion are the main forces involved in morphing the cells into critical anatomical structures. The ability of a cell to migrate to its correct destination depends heavily on signaling at the cell membrane. Erythropoietin producing hepatocellular carcinoma (EPH) receptors and their ligands, the ephrins (EPH receptors interacting proteins, EFNs), orchestrates the precise control necessary to guide a cell to its destination. They are expressed in all tissues of a developing embryo and are involved in multiple developmental processes such as axon guidance, cardiovascular and skeletal development and tissue patterning. In addition, EPH receptors and EFNs are expressed in developing and mature synapses in the nervous system, where they may have a role in regulating synaptic plasticity and long-term potentiation. Activation of EPHB receptors in neurons induces the rapid formation and enlargement of dendritic spines, as well as rapid synapse maturation (Dalva et al. 2007). On the other hand, EPHA4 activation leads to dendritic spine elimination (Murai et al. 2003, Fu et al. 2007). EPH receptors are the largest known family of receptor tyrosine kinases (RTKs), with fourteen total receptors divided into either A- or B-subclasses: EPHA (1-8 and 10) and EPHB (1-4 and 6). EPH receptors can have overlapping functions, and loss of one receptor can be partially compensated for by another EPH receptor that has similar expression pattern and ligand-binding specificities. EPH receptors have an N-terminal extracellular domain through which they bind to ephrin ligands, a short transmembrane domain, and an intracellular cytoplasmic signaling structure containing a canonical tyrosine kinase catalytic domain as well as other protein interaction sites. Ephrins are also sub-divided into an A-subclass (A1-A5), which are tethered to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor, and a B-subclass (B1-B3), members of which have a transmembrane domain and a short, highly conserved cytoplasmic tail lacking endogenous catalytic activity. The interaction between EPH receptors and its ligands requires cell-cell interaction since both molecules are membrane-bound. Close contact between EPH receptors and EFNs is required for signaling to occur. EPH/EFN-initiated signaling occurs bi-directionally into either EPH- or EFN-expressing cells or axons. Signaling into the EPH receptor-expressing cell is referred as the forward signal and signaling into the EFN-expressing cell, the reverse signal. (Dalva et al. 2000, Grunwald et al. 2004, Davy & Robbins 2000, Cowan et al. 2004)"
BMGC_PW0929,BMG_PW3334,,,NOTCH1 heterodimerization domain mutations are frequently found in T-cell acute lymphoblastic leukemia (T-ALL) (Weng et al. 2004) and result in constitutive activity of NOTCH1 mutants (Malecki et al. 2006).
BMGC_PW0930,BMG_PW3335,,,"The heterodimerization (HD) domain of NOTCH1, responsible for association of NOTCH1 extracellular and transmembrane regions after furin-mediated cleavage of NOTCH1 precursor, is one of the hotspots for gain-of-function NOTCH1 mutations in T-cell acute lymphoblastic leukemia (T-ALL) (Weng et al. 2004). NOTCH1 HD domain mutants are responsive to ligand binding, but the activation (through cleavage of S2 and S3 sites and release of the intracellular domain NICD1) also happens spontaneously, in the absence of DLL and JAG ligands (Malecki et al. 2006). The following NOTCH1 HD domain mutants were directly functionally studied by Malecki et al.: NOTCH1 V1576E, NOTCH1 F1592S, NOTCH1 L1593P, NOTCH1 L1596H, NOTCH1 R1598P, NOTCH1 I1616N, NOTCH1 I1616T, NOTCH1 V1676D, NOTCH1 L1678P, NOTCH1 I1680N, NOTCH1 A1701P and NOTCH1 I1718T; other frequent NOTCH1 HD domain mutants (NOTCH1 L1574P, NOTCH1 L1574Q and NOTCH1 L1600P) are assumed to behave in a similar way."
BMGC_PW0931,BMG_PW3336,,,"The lipid raft resident adaptor molecules LAT1 and Non-T cell activation linker (NTAL), also known as linker for activation of B cells (LAB)/LAT2 are known participants in the regulation of mast cell calcium responses. Both LAT and NTAL are expressed and phosphorylated following engagement of FCERI on mast cells. NTAL is functionally and topographically different from LAT. There is a considerable debate on the role of NTAL in mast cell. Depending on the circumstances, NTAL appears to have a dual role as positive and negative regulator of MC responses elicited via FCERI. Studies conducted in bone marrow-derived mast cells (BMMCs) of mice lacking NTAL displayed enhanced FCERI-mediated tyrosine phosphorylation of several substrates, calcium response, degranulation, and cytokine production. This indicated that NTAL negatively regulates FCERI-mediated degranulation. However, in mice lacking both LAT and NTAL showed severe block in FCERI-mediated signaling than BMMCs deficient in LAT alone, suggesting that NTAL also shares a redundant function with LAT to play a positive role (Draberova et al. 2007, Orr & McVicar. 2011, Zhu et al. 2004, Volna et al. 2004). The major steps in NTAL mediated Ca+2 influx involves NTAL--> GAB2--> PI3K"
BMGC_PW0932,BMG_PW3337,,,"Ficolins are recognition molecules in the lectin pathway of complement activation. Three types of ficolin have been identified in humans: M-ficolin (ficolin-1, FCN1), L-ficolin (ficolin-2, FCN2) and H-ficolin (ficolin-3, FCN3). FCN2 and 3 circulate in blood plasma whereas FCN1 is locally secreted by immune response cells (Teh et al. 2000, Liu et al. 2005, Matsushita et al. 2002). Plasma ficolins circulate as complexes with MBL-associated serine proteases (MASPs). Upon binding of ficolins to carbohydrates on the target cell surface, MASPs are activated and subsequently activate the complement cascade (Matsushita et al. 2002, Gout et al. 2009). Ficolins function as trimers and larger oligomers. Ficolin peptide sequences contain an amino-terminal cysteine-rich region, a collagen-like domain, a neck region and a carboxy-terminal fibrinogen-like domain. The fibrinogen-like domain binds to pathogen- or apoptotic cell-associated molecular patterns. Different ficolins have distinct recognition specificities (Endo et al. 2007, Thiel and Gadjeva 2009, Garlatti et al. 2010)."
BMGC_PW0933,BMG_PW3338,,,"Formation of the LAT signaling complex leads to activation of MAPK and production of cytokines. The sequence of events that leads from LAT to cytokine production has not been as clearly defined as the sequence that leads to degranulation. However, the pathways that lead to cytokine production require the guanine-nucleotide-exchange factors SOS and VAV that regulate GDP-GTP exchange of RAS. After its activation, RAS positively regulates the RAF-dependent pathway that leads to phosphorylation and, in part, activation of the mitogen-activated protein kinases (MAPKs) extracellular-signal-regulated kinase 1 (ERK1) and ERK2 (Gilfillan & Tkaczyk 2006)."
BMGC_PW0934,BMG_PW3339,,,"Increase of intracellular calcium in mast cells is most crucial for mast cell degranulation. Elevation of intracellular calcium is achieved by activation of PLC-gamma. Mast cells express both PLC-gamma1 and PLC-gamma2 isoforms and activation of these enzymes leads to conversion of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol triphosphate (IP3) and diacylglycerol (DAG). The production of IP3 leads to mobilization of intracellular Ca+2, which later results in a sustained Ca+2 flux response that is maintained by an influx of extracellular Ca+2. In addition to degranulation, an increase in intracellular calcium concentration also activates the Ca2+/calmodulin-dependent serine phosphatase calcineurin. Calcineurin dephosphorylates the nuclear factor for T cell activation (NFAT) which exposes nuclear-localization signal sequence triggering translocation of the dephosphorylated NFAT-CaN complex to the nucleus. Once in the nucleus, NFAT regulates the transcription of several cytokine genes (Kambayashi et al. 2007, Hoth & Penner 1992, Ebinu et al. 2000, Siraganian et al)."
BMGC_PW0935,BMG_PW3340,,,"The increase in intracellular Ca+2 in conjunction with DAG also activates PKC and RasGRP, which inturn contributes to cytokine production by mast cells (Kambayashi et al. 2007). Activation of the FCERI engages CARMA1, BCL10 and MALT1 complex to activate NF-kB through PKC-theta (Klemm et al. 2006, Chen et al. 2007). FCERI stimulation leads to phosphorylation, and degradation of IkB which allows the release and nuclear translocation of the NF-kB proteins. Activation of the NF-kB transcription factors then results in the synthesis of several cytokines. NF-kB activation by FCERI is critical for proinflammatory cytokine production during mast cell activation and is crucial for allergic inflammatory diseases (Klemm et al. 2006)."
BMGC_PW0936,BMG_PW3341,,,"POU5F1 (OCT4), SOX2, and NANOG bind elements in the promoters of target genes. The target genes of each transcription factor overlap extensively: POU5F1, SOX2, and NANOG co-occupy at least 353 genes (Boyer et al. 2005). About half of POU5F1 targets also bind SOX2 and about 90% of these also bind NANOG (Boyer et al. 2005). Upon binding the transcription factors activate expression of one subset of target genes in the core transcriptional network of pluripotent stem cells and repress another subset (Kim et al. 2006, Matoba et al. 2006, Player et al. 2006, Assou et al. 2007, Babaie et al. 2007, Chavez et al. 2009, Jung et al. 2010). The target genes listed in this module are the repressed genes. Caution must be used when making inferences about human stem cells from mouse stem cells because of significant differences between the two species (Ginis et al. 2004)."
BMGC_PW0937,BMG_PW3342,,,"POU5F1 (OCT4), SOX2, and NANOG bind elements in the promoters of target genes. The target genes of each transcription factor overlap extensively: POU5F1, SOX2, and NANOG co-occupy at least 353 genes (Boyer et al. 2005). About half of POU5F1 targets also bind SOX2 and about 90% of these also bind NANOG (Boyer et al. 2005). Upon binding the transcription factors activate expression of one subset of target genes and repress another subset (Kim et al. 2006, Matoba et al. 2006, Player et al. 2006, Babaie et al. 2007). The targets listed in this module are those that have been described as composing activated genes in the core transcriptional network of pluripotent stem cells (Assou et al. 2007, Chavez et al. 2009, Jung et al. 2010). Inferences from mouse to human have been made with caution because of significant differences between the two species (Ginis et al. 2004)."
BMGC_PW0938,BMG_PW3343,,,"Mutations in the heterodimerization domain (HD) and PEST domain of NOTCH1 are frequently found in cis in T-cell acute lymphoblastic leukemia. While HD mutations alone result in up to ~10-fold increase in NOTCH1 transcriptional activity and PEST domain mutations alone result in up to ~2-fold increase in NOTCH1 transcriptional activity, in cis mutations of HD and PEST domains act synergistically, increasing NOTCH1 transcriptional activity up to ~40-fold (Weng et al. 2004)."
BMGC_PW0939,BMG_PW3344,,,"When found in cis, HD and PEST domain mutations act synergistically, increasing NOTCH1 transcriptional activity up to ~40-fold, compared with up to ~10-fold and up to ~2-fold increase with HD mutations alone and PEST domain mutations alone, respectively (Weng et al. 2004). HD domain mutations enable spontaneous, ligand-independent, proteolytic release of the NICD1 fragment, although mutants remain responsive to ligand binding (Malecki et al. 2006), while PEST domain mutations prolong NICD1 half-life and transcriptional activity through interference with FBXW7 (FBW7)-mediated ubiquitination and degradation (Thompson et al. 2007, O'Neil et al. 2007). NOTCH1 HD+PEST domain mutants annotated here are NOTCH1 L1600P;P2514Rfs*4, NOTCH1 L1600P;Q2440*, NOTCH1 L1600P;Q2395* and NOTCH1 L1574P;P2474Afs*4."
BMGC_PW0940,BMG_PW3346,,,"Similar to NOTCH1, NOTCH2 is activated by Delta-like and Jagged ligands (DLL/JAG) expressed in trans on a neighboring cell (Shimizu et al. 1999, Shimizu et al. 2000, Hicks et al. 2000, Ji et al. 2004). The activation triggers cleavage of NOTCH2, first by ADAM10 at the S2 cleavage site (Gibb et al. 2010, Shimizu et al. 2000), then by gamma-secretase at the S3 cleavage site (Saxena et al. 2001, De Strooper et al. 1999), resulting in the release of the intracellular domain of NOTCH2, NICD2, into the cytosol. NICD2 subsequently traffics to the nucleus where it acts as a transcription regulator. While DLL and JAG ligands are well established, canonical NOTCH2 ligands, there is limited evidence that NOTCH2, similar to NOTCH1, can be activated by CNTN1 (contactin 1), a protein involved in oligodendrocyte maturation (Hu et al. 2003). MDK (midkine), which plays an important role in epithelial to mesenchymal transition, can also activate NOTCH2 signaling and is able to bind to the extracellular domain of NOTCH2, but the exact mechanism of MDK-induced NOTCH2 activation has not been elucidated (Huang et al. 2008, Gungor et al. 2011)."
BMGC_PW0941,BMG_PW3347,,,"Peptide hormones are cleaved from larger precursors in the secretory system (endoplasmic reticulum, Golgi apparatus, secretory granules) of the cell. After secretion peptide hormones are modified and degraded by extracellular proteases. Insulin processing occurs in 4 steps: formation of intramolecular disulfide bonds, formation of proinsulin-zinc-calcium complexes, proteolytic cleavage of proinsulin by PCSK1 (PC1/3) and PCSK2 to yield insulin, translocation of the granules across the cytosol to the plasma membrane. During Synthesis, secretion, and deacetylation of Ghrelin, proghrelin is acylated by ghrelin O-acyltransferase and cleaved by PCSK1 to yield the mature acyl ghrelin and C-ghrelin. In the bloodstream acyl ghrelin is deacylated by butyrylcholinesterase and platelet-activating factor acetylhydrolase. During Metabolism of Angiotensinogen to Angiotensin, Renin cleaves angiotensinogen to yield a decapaptide, angiotensin I (angiotensin-1, angiotensin-(1-10)). Two C-terminal amino acid residues of angiotensin I are then removed by angiotensin-converting enzyme (ACE), located on the surface of endothelial cells, to yield angiotensin II (angiotensin-2, angiotensin-(1-8)), the active peptide that causes vasoconstriction, resorption of sodium and chloride, excretion of potassium, water retention, and aldosterone secretion. More recently other, more tissue-localized pathways leading to angiotensin II and alternative derivatives of angiotensinogen have been identified and described. Incretin synthesis, secretion, and inactivation occurs through processing of incretin precursors (preproGLP-1 and preproGIP) by PCSK1. After secretion both incretins (GLP-1 and GIP) can be inactivated by cleavage by DPP4. Peptide hormone biosynthesis describes processing of glycoprotein hormones (those which include carbohydrate side-chains) and corticotropin."
BMGC_PW0942,BMG_PW3348,,,"The nuclear envelope breakdown (NEBD) happens in late prophase of mitosis and involves disassembly of the nuclear pore complex, depolymerization of the nuclear lamina, and clearance of nuclear envelope from chromatin. NEBD allows mitotic spindle microtubules to access condensed chromosomes at kinetochores and enables nuclear division and segregation of genetic material to two daughter cells. For a recent review, please refer to Guttinger et al. 2009. In mitotic prophase, chromatin detaches from the nuclear envelope, and this contributes to the nuclear envelope breakdown. VRK1 (and possibly VRK2) mediated phosphorylation of BANF1 (BAF), a protein that simultaneously interacts with DNA, LEM-domain inner nuclear membrane proteins, and lamins (Zheng et al. 2000, Shumaker et al. 2001, Haraguchi et al. 2001, Mansharamani and Wilson 2005, Brachner et al. 2005) is considered to be one of the key steps in the detachment of the nuclear envelope from chromatin (Bengtsson and Wilson 2006, Nichols et al. 2006, Gorjanacz et al. 2007)."
BMGC_PW0943,BMG_PW3349,,,"NEK6 and NEK7 are activated during mitosis by another NIMA family kinase, NEK9 (Belham et al. 2003, Richards et al. 2009), which is activated by CDK1- and PLK1-mediated phosphorylation (Roig et al. 2002, Bertran et al. 2011)."
BMGC_PW0944,BMG_PW3350,,,"Reassembly of the nuclear envelope (NE) is initiated at late anaphase/early telophase when BANF1 (BAF), which is dispersed throughout the cytoplasm during metaphase, accumulates on the surfaces of coalesced chromosomes. This is coordinated with the chromatin association of membranes and inner nuclear membrane proteins that include EMD (emerin), TMPO (LAP2beta), LEMD3 (MAN1) and LEMD2 (LEM2), and lamins (Haraguchi et al. 2008, reviewed by Wandke and Kutay 2013). The DNA-cross-bridging activity of BANF1 is required for individual chromosomes to properly coalesce for enclosure in a single nucleus (Samwer et al. 2017)."
BMGC_PW0945,BMG_PW3351,,,"Reassembly of the nuclear envelope (NE) around separated sister chromatids begins in late anaphase and is completed in telophase (reviewed by Wandke and Kutay 2013). Characteristic proteins of the inner nuclear membrane and nuclear lamina accumulate at the reforming NE (reviewed by Wandke and Kutay 2013). Concurrently, nuclear pore complexes (NPCs) assemble and insert into the reforming NE, and the NE becomes sealed to reestablish the nucleocytoplasmic diffusion barrier (reviewed by Otsuka and Ellenberg 2018)."
BMGC_PW0946,BMG_PW3352,,,"Laminins are a large family of conserved, multidomain trimeric basement membrane proteins. There are many theoretical trimer combinations but only 18 have been described (Domogatskaya et al. 2012, Miner 2008, Macdonald et al. 2010) and the existence of isoforms laminin-212 and/or laminin-222 (Durbeej et al. 2010) awaits further confirmation. The chains assemble through coiled-coil domains at their C-terminal end. Alpha chains additionally have a large C-terminal globular domain containing five LG subdomains (LG1-5). The N termini are often referred to as the short arms. These have varying numbers of laminin-type epidermal growth factor-like (LE) repeats. Trimer assembly is controlled by highly specific coiled-coil interactions (Domogatskaya et al. 2012). Some laminin isoforms are modified extracellularly by proteolytic processing at the N- or C-terminal ends prior to their binding to cellular receptors or other matrix molecules (Tzu & Marinkovitch 2008). The cell adhesion properties of laminins are mediated primarily through the alpha chain G domain to integrins, dystroglycan, Lutheran glycoprotein, or sulfated glycolipids. The N-terminal globular domains of the alpha-1 (Colognato-Pyke et al. 1995) and alpha-2 chains (Colognato et al. 1997) and globular domains VI (Nielsen & Yamada 2001) and IVa (Sasaki & Timpl 2001) of the alpha-5 chain can bind to several integrin isoforms (alpha1beta1, alpha2beta1, alpha3beta1, and alphaVbeta3), which enables cell binding at both ends of laminins with these alpha chains."
BMGC_PW0947,BMG_PW3353,,,"Syndecans are type I transmembrane proteins, with an N-terminal ectodomain that contains several consensus sequences for glycosaminoglycan (GAG) attachment and a short C-terminal cytoplasmic domain. Syndecan-1 and -3 GAG attachment sites occur in two distinct clusters, one near the N-terminus and the other near the membrane-attachment site, separated by a proline and threonine-rich 'spacer'. Syndecan ectodomain sequences are poorly conserved in the family and between species, but the transmembrane and cytoplasmic domains are highly conserved. Syndecan-1 and -3 form a subfamily. Syndecan core proteins form dimers (Choi et al. 2007) and at least syndecan-3 and -4 form oligomers (Asundi & Carey 1995, Shin et al. 2012). Syndecan-1 is the major syndecan of epithelial cells including vascular endothelium. Syndecan-2 is present mostly in mesenchymal, neuronal and smooth muscle cells. Syndecan-3 is the major syndecan of the nervous system, while syndecan-4 is ubiquitously expressed but at lower levels than the other syndecans (refs in Alexopoulou et al. 2007). The core syndecan protein has three to five heparan sulfate or chondroitin sulfate chains, which interact with a variety of ligands including fibroblast growth factors, vascular endothelial growth factor, transforming growth factor-beta, fibronectin, collagen, vitronectin and several integrins. Syndecans may act as integrin coreceptors. Interactions between fibronectin and syndecans are modulated by tenascin-C. Syndecans bind a wide variety of soluble and insoluble ligands, inckluding extracellular matrix components, cell adhesion molecules, growth factors, cytokines, and proteinases. As the cleaved ectodomains of syndecans retain the ability to bind ligands, ectodomain shedding is a mechanism for releasing soluble effectors that may compete for ligands with their cell-bound counterparts (Kainulainen et al. 1998). Shed ectodomains are found in inflammatory fluids (Subramanian et al. 1997) and may induce the proliferation of cancer cells (Maeda et al. 2004)."
BMGC_PW0948,BMG_PW3354,,,"Several non-integrin membrane proteins interact with extracellular matrix proteins. Transmembrane proteoglycans may associate with integrins and growth factor receptors to influence their function, or they can signal independently, often influencing the actin cytoskeleton."
BMGC_PW0949,BMG_PW3355,,,"Proteoglycans are major components of the extracellular matrix. In cartilage the matrix constitutes more than 90% of tissue dry weight. Proteoglycans are proteins substituted with glycosaminoglycans (GAGs), linear polysaccharides consisting of a repeating disaccharide, generally of an acetylated amino sugar alternating with a uronic acid. Most proteoglycans are located in the extracellular space. Proteoglycans are highly diverse, both in terms of the core proteins and the subtypes of GAG chains, namely chondroitin sulfate (CS), keratan sulfate (KS), dermatan sulfate (DS) and heparan sulfate (HS). Hyaluronan is a non-sulfated GAG whose molecular weight runs into millions of Dalton; in articular cartilage, a single hyaluronan molecule can hold upto 100 aggrecan molecules and these aggregates are stabilized by a link protein."
BMGC_PW0950,BMG_PW3356,,,"Class B receptors have two transmembrane domains separated by an extracellular loop (reviewed in Adachi and Tsujimoto 2006, Areschoug and Gordon 2009)."
BMGC_PW0951,BMG_PW3357,,,"Class A scavenger receptors contain an intracellular domain, a transmembrane region, a coiled-coil domain, a collagenous domain, and the SR cysteine-rich domain (reviewed in Areschoug and Gordon 2009, Bowdish and Gordon 2009). The coiled coil domains interact to form trimers. The collagenous domain (Rohrer et al. 1990, Acton et al. 1993) and/or the SR cysteine-rich domain (Brannstrom et al. 2002) bind ligands and determine the specificity of the receptor."
BMGC_PW0952,BMG_PW3358,,,"SCARF1 (SREC-I) and SCARF2 (SREC-II) are transmembrane proteins that contain multiple extracellular EGF-like domains (Ishii et al. 2002, reviewed in Areschoug and Gordon 2009). SCARF2 may be involved in cell adhesion rather than ligand binding."
BMGC_PW0953,BMG_PW3360,,,"The UBA2:SAE1 complex catalyzes the formation of a thioester linkage between the C-terminal glycine of the mature SUMO and a cysteine residue (cysteine-173) in UBA2 (SAE2) (reviewed in Wang and Dasso 2009, Wilkinson and Henley 2010, Hannoun et al. 2010, Gareau and Lima 2010). During the process the C-terminal glycine residue of SUMO is reacted with ATP to yield pyrophosphate and a transient intermediate, SUMO adenylate. The SUMO adenylate then reacts with the thiol group of the cysteine residue of UBA2 (Olsen et al. 2010)."
BMGC_PW0954,BMG_PW3361,,,"SUMO is transferred from cysteine-173 of UBA2 to cysteine-93 of UBC9 (UBE2I) in a transthiolation reaction (reviewed in Wang and Dasso 2009, Wilkinson and Henley 2010, Hannoun et al. 2010, Gareau and Lima 2010). UBC9 is the only known E2 enzyme for SUMO and on certain substrates such as RanGAP1 may act without the requirement of an E3 ligase."
BMGC_PW0955,BMG_PW3363,,,"Several factors that participate in DNA damage response and repair are SUMOylated (reviewed in Dou et al. 2011, Bekker-Jensen and Mailand 2011, Ulrich 2012, Psakhye and Jentsch 2012, Bologna and Ferrari 2013, Flotho and Melchior 2013, Jackson and Durocher 2013). SUMOylation can alter enzymatic activity and protein stability or it can serve to recruit additional factors. For example, SUMOylation of Thymine DNA glycosylase (TDG) causes TDG to lose affinity for its product, an abasic site opposite a G residue, and thus increases turnover of the enzyme. During repair of double-strand breaks SUMO1, SUMO2, SUMO3, and the SUMO E3 ligases PIAS1 and PIAS4 accumulate at double-strand breaks where BRCA1, HERC1, RNF168, MDC1, and TP53BP1 are SUMOylated. SUMOylation of BRCA1 may increase its ubiquitin ligase activity while SUMOylation of MDC1 and HERC2 appears to play a role in recruitment of proteins such as RNF4 and RNF8 to double strand breaks. Similarly SUMOylation of RPA1 (RPA70) recruits RAD51 in the homologous recombination pathway."
BMGC_PW0956,BMG_PW3364,,,"SUMO proteins are conjugated to lysine residues of target proteins via an isopeptide bond with the C-terminal glycine of SUMO (reviewed in Zhao 2007, Gareau and Lima 2010, Hannoun et al. 2010, Citro and Chiocca 2013, Yang and Chiang 2013). Proteomic analyses indicate that SUMO is conjugated to hundreds of proteins and most targets of SUMOylation are nuclear (Vertegal et al. 2006, Bruderer et al. 2011, Tatham et al. 2011, Da Silva et al. 2012, Becker et al. 2013). Within the nucleus SUMOylation targets include transcription factors (TFs), transcription cofactors (TCs), intracellular (nuclear) receptors, RNA binding proteins, RNA splicing proteins, polyadenylation proteins, chromatin organization proteins, DNA replication proteins, DNA methylation proteins, DNA damage response and repair proteins, immune response proteins, SUMOylation proteins, and ubiquitinylation proteins. Mitochondrial fission proteins are SUMOylated at the mitochondrial outer membrane. UBE2I (UBC9), the E2 activating enzyme of the SUMO pathway, is itself also a SUMO E3 ligase. Most SUMOylation reactions will proceed with only the substrate protein and the UBE2I:SUMO thioester conjugate. The rates of some reactions are further enhanced by the action of other E3 ligases such as RANBP2. These E3 ligases catalyze SUMO transfer to substrate by one of two basic mechanisms: they interact with both the substrate and UBE2I:SUMO thus bringing them into proximity or they enhance the release of SUMO from UBE2I to the substrate. In the cell SUMO1 is mainly concentrated at the nuclear membrane and in nuclear bodies. Most SUMO1 is conjugated to RANGAP1 near the nuclear pore. SUMO2 is at least partially cytosolic and SUMO3 is located mainly in nuclear bodies. Most SUMO2 and SUMO3 is unconjugated in unstressed cells and becomes conjugated to target proteins in response to stress (Golebiowski et al. 2009). Especially notable is the requirement for recruitment of SUMO to sites of DNA damage where conjugation to targets seems to coordinate the repair process (Flotho and Melchior 2013). Several effects of SUMOylation have been described: steric interference with protein-protein interactions, interference with other post-translational modifications such as ubiquitinylation and phosphorylation, and recruitment of proteins that possess a SUMO-interacting motif (SIM) (reviewed in Zhao 2007, Flotho and Melchior 2013, Jentsch and Psakhye 2013, Yang and Chiang 2013). In most cases SUMOylation inhibits the activity of the target protein. The SUMOylation reactions included in this module have met two criteria: They have been verified by assays of individual proteins (as opposed to mass proteomic assays) and the effect of SUMOylation on the function of the target protein has been tested."
BMGC_PW0957,BMG_PW3365,,,"DHX36 and DHX9 are aspartate-glutamate-any amino acid aspartate/histidine (DExD/H) box helicase (DHX) proteins that localize in the cytosol. The DHX RNA helicases family includes a large number of proteins that are implicated in RNA metabolism. Members of this family, RIG-1 and MDA5, have been shown to sense a non-self RNA leading to type I IFN production. RNA helicases DHX36 and DHX9 were found to trigger host responses to non-self DNA in MyD88-dependent manner. DHX36 sensed CpG class A, while DHX9 sensed CpG class B. Both DHX36 and DHX9 were critical for antiviral immune responses in viral DNA-stimulated human plasmacytoid dendritic cells (pDC) (Kim T et al. 2010)."
BMGC_PW0958,BMG_PW3366,,,Leucine-rich repeat flightless-interacting protein 1 (LRRFIP1) can bind exogenous double-stranded RNA and double-stranded DNA (Wilson SA et al. 1998; Yang P et al. 2010). LRRFIP1 was shown to mediate Listeria monocytogenes- and vesicular stomatitis virus (VSV)-induced IFN-beta production in mouse primary macrophages by regulating beta-catenin activity. Beta-catenin possibly functions as a transcriptional cofactor of IRF3 to initiate Ifnb1 transcription (Yang P et al. 2010).
BMGC_PW0959,BMG_PW3367,,,Innate immune responses are coordinated and regulated to provide an efficient first line of defense against pathogens and at the same time to prevent host self-damage. Here we present some regulatory events involved in the detection of cytosolic nucleic acids.
BMGC_PW0960,BMG_PW3368,,,"Lysine deacetylases (KDACs), historically referred to as histone deacetylases (HDACs), are divided into the Rpd3/Hda1 metal-dependent 'classical HDAC family' (de Ruijter et al. 2003, Verdin et al. 2003) and the unrelated sirtuins (Milne & Denu 2008). Phylogenetic analysis divides human KDACs into four classes (Gregoretti et al. 2004): Class I includes HDAC1, 2, 3 and 8; Class IIa includes HDAC4, 5, 7 and 9; Class IIb includes HDAC6 and 10; Class III are the sirtuins (SIRT1-7); Class IV has one member, HDAC11 (Gao et al. 2002). Class III enzymes use an NAD+ cofactor to perform deacetylation (Milne & Denu 2008, Yang & Seto 2008), the others classes use a metal-dependent mechanism (Gregoretti et al. 2004) to catalyze the hydrolysis of acetyl-L-lysine side chains in histone and non-histone proteins yielding L-lysine and acetate. X-ray crystal structures are available for four human HDACs; these structures have conserved active site residues, suggesting a common catalytic mechanism (Lombardi et al. 2011). They require a single transition metal ion and are typically studied in vitro as Zn2+-containing enzymes, though in vivo HDAC8 exhibits increased activity when substituted with Fe2+ (Gantt et al. 2006). The structurally-related enzyme acetylpolyamine amidohydrolase (APAH) (Leipe & Landsman 1997) exhibits optimal activity with Mn2+, followed closely by Zn2+ (Sakurada et al. 1996). HDACs are often part of multi-protein transcriptional complexes that are recruited to gene promoters, regulating transcription without direct DNA binding. With the exception of HDAC8, all class I members can be catalytic subunits of multiprotein complexes (Yang & Seto 2008). HDAC1 and HDAC2 interact to form the catalytic core of several multisubunit complexes including Sin3, nucleosome remodeling deacetylase (NuRD) and corepressor of REST (CoREST) complexes (Grozinger & Schreiber 2002). HDAC3 is part of the silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) complex or the homologous nuclear receptor corepressor (NCoR) (Li et al. 2000, Wen et al. 2000, Zhang et al. 2002, Yoon et al. 2003, Oberoi et al. 2011) which are involved in a wide range of processes including metabolism, inflammation, and circadian rhythms (Mottis et al. 2013). Class IIa HDACs (HDAC4, -5, -7, and -9) shuttle between the nucleus and cytoplasm (Yang & Seto 2008, Haberland et al. 2009). The nuclear export of class IIa HDACs requires phosphorylation stimulated by calcium or other stimuli. They appear to have been evolutionarily inactivated as enzymes, having acquired a histidine substitution of the tyrosine residue in the active site of the mammalian deacetylase domain (H976 in humans) (Lahm et al. 2007, Schuetz et al. 2008). Instead they function as transcriptional corepressors for the MEF2 family of transcription factors (Yang & Gregoire 2005) . Histones are the primary substrate for most HDACs except HDAC6 which is predominantly cytoplasmic and acts on alpha-tublin (Hubbert et al. 2002, Zhang et al. 2003, Boyault et al. 2007). HDACs also deacetylate proteins such as p53, E2F1, RelA, YY1, TFIIE, BCL6 and TFIIF (Glozak et al. 2005). Histone deacetylases are targeted by structurally diverse compounds known as HDAC inhibitors (HDIs) (Marks et al. 2000). These can induce cytodifferentiation, cell cycle arrest and apoptosis of transformed cells (Marks et al. 2000, Bolden et al. 2006). Some HDIs have significant antitumor activity (Marks and Breslow 2007, Ma et al. 2009) and at least two are approved anti-cancer drugs. The coordinates of post-translational modifications represented and described here follow UniProt standard practice whereby coordinates refer to the translated protein before any further processing. Histone literature typically refers to coordinates of the protein after the initiating methionine has been removed. Therefore the coordinates of post-translated residues in the Reactome database and described here are frequently +1 when compared with the literature."
BMGC_PW0961,BMG_PW3369,,,"Lysine methyltransferases (KMTs) and arginine methyltransferases (RMTs) have a common mechanism of catalysis. Both families transfer a methyl group from a common donor, S-adenosyl-L-methionine (SAM), to the nitrogen atom on the epsilon-amino group of lysine or arginine (Smith & Denu 2009) using a bimolecular nucleophillic substitution (SN2) methyl transfer mechanism (Smith & Denu 2009, Zhang & Bruice 2008). All human KMTs except DOT1L (KMT4) (Feng et al. 2002, van Leeuwen et al. 2002, Lacoste et al. 2002) have a ~130 amino acid catalytic domain referred to as the SET domain (Del Rizzo & Trievel 2011, Dillon et al. 2005, Herz et al. 2013). Some KMTs selectively methylate a particular lysine residue on a specific histone type. The extent of this methylation (mono-, di- or tri-methylation) also can be stringent (Herz et al. 2013, Copeland et al. 2009). Many KMTs also have non-histone substrates (Herz et al 2013), which are not discussed in this module. The coordinates of post-translational modifications represented and described here follow UniProt standard practice whereby coordinates refer to the translated protein before any processing. Histone literature typically refers to specific residues by numbers which are determined after the initiating methionine has been removed. Therefore the coordinates of post-translated residues in the Reactome database and described here are frequently +1 when compared to the histone literature. SET domain-containing proteins are classified in one of 7 families (Dillon et al. 2005). First to be discovered were the SUV39 family named after founding member SUV39H1 (KMT1A), which selectively methylates lysine-10 of histone H3 (H3K9) (Rea et al. 2000). Family member EHMT2 (KMT1C, G9A) is the predominant H3K9 methyltransferase in mammals (Tachibana et al. 2002). SETDB1 (KMT1E, ESET) also predominantly methylates H3K9, most effectively when complexed with ATF7IP (MCAF, hAM) (Wang et al. 2003). SETD2 (KMT3A, HYPB), a member of the SET2 family, specifically methylates histone H3 lysine-37 (H3K36) (Sun et al. 2005). WHSC1 (KMT3G, NSD2, MMSET) a member of the same family, targets H3K36 when provided with nucleosome substrates but also can methylate histone H4 lysine-45 when octameric native or recombinant nucleosome substrates are provided (Li et al. 2009); dimethylation of histone H3 at lysine-37 (H3K36me2) is thought to be the principal chromatin-regulatory activity of WHSC1 (Kuo et al. 2011). Relatives NSD1 (KMT3B) and WHSC1L1 (KMT3F, NSD3) also methylate nucleosomal H3K36. NSD1 is active on unmethylated or a mimetic monomethylated H3K36, but not di- or trimethylated H3K36 mimetics (Li et al. 2009). Human SETD7 (KMT7, SET7/9), not classified within the 7 SET-domain containing families, mono-methylates lysine-5 of histone H3 (H3K4) (Xiao et al. 2003)."
BMGC_PW0962,BMG_PW3370,,,"Histone lysine demethylases (KDMs) are able to reverse N-methylations of histones and probably other proteins. To date KDMs have been demonstrated to catalyse demethylation of N-epsilon methylated lysine residues. Biochemically there are two distinct groups of N-epsilon methylated lysine demethylases with different catalytic mechanisms, both of which result in methyl group oxidation to produce formaldhyde. KDM1A, formerly known as Lysine Specific Demethylase 1 (LSD1), belongs to the flavin adenine dinucleotide (FAD)-dependent amino oxidase family. The KDM1A reaction mechanism requires a protonatable lysine epsilon-amine group, not available in trimethylated lysines, which consequently are not KDM1 substrates. Other KDMs belong to the Jumonji C (JmjC) -domain containing family. These are members of the Cupin superfamily of mononuclear Fe (II)-dependent oxygenases, which are characterised by the presence of a double-stranded beta-helix core fold. They require 2-oxoglutarate (2OG) and molecular oxygen as co-substrates, producing, in addition to formaldehyde, succinate and carbon dioxide. This hydroxylation-based mechanism does not require a protonatable lysine epsilon-amine group and consequently JmjC-containing demethylases are able to demethylate tri-, di- and monomethylated lysines. The coordinates of post-translational modifications represented and described here follow UniProt standard practice whereby coordinates refer to the translated protein before any further processing. Histone literature typically refers to coordinates of the protein after the initiating methionine has been removed. Therefore the coordinates of post-translated residues in the Reactome database and described here are frequently +1 when compared with the literature. In general, methylation at histone H3 lysine-5 (H3K4) and lysine-37 (H3K36), including di- and trimethylation at these sites, has been linked to actively transcribed genes (reviewed in Martin & Zhang 2005). In contrast, lysine-10 (H3K9) promoter methylation is considered a repressive mark for euchromatic genes and is also one of the landmark modifications associated with heterochromatin (Peters et al. 2002). The first reported JmjC-containing demethylases were KDM2A/B (JHDM1A/B, FBXL11/10). These catalyse demethylation of histone H3 lysine-37 when mono- or di-methylated (H3K36Me1/2) (Tsukada et al. 2006). They were found to contain a JmjC catalytic domain, previously implicated in chromatin-dependent functions (Clissold & Ponting 2001). Subsequently, many other JmjC enzymes have been identified and discovered to have lysine demethylase activities with distinct methylation site and state specificities. KDM3A/B (JHDM2A/B) are specific for mono or di-methylated lysine-10 on histone H3 (H3K9Me1/2) (Yamane et al. 2006, Kim et al. 2012). KDM4A-C (JMJD2A-C/JHDM3A-C) catalyse demethylation of di- or tri-methylated histone H3 at lysine-10 (H3K9Me2/3) (Cloos et al. 2006, Fodor et al. 2006), with a strong preference for Me3 (Whetstine et al. 2007). KDM4D (JMJD2D) also catalyses demethylation of H3K9Me2/3 (Whetstine et al. 2007). KDM4A-C (JHDM3A-C) can also catalyse demethylation of lysine-37 of histone H3 (H3K36Me2/3) (Klose et al. 2006). KDM5A-D (JARID1A-D) catalyses demethylation of di- or tri-methylated lysine-5 of histone H3 (H3K4Me2/3) (Christensen et al. 2007, Klose et al. 2007, Lee et al. 2007, Secombe et al. 2007, Seward et al. 2007, Iwase et al. 2007). KDM6A and KDM6B (UTX/JMJD3) catalyse demethylation of di- or tri-methylated lysine-28 of histone H3 (H3K27Me2/3) (Agger et al. 2007, Cho et al. 2007, De Santra et al. 2007, Lan et al. 2007, Lee et al. 2007). KDM7A (KIAA1718/JHDM1D) catalyses demethylation of mono- or di-methylated lysine-10 of histone H3 (H3K9Me1/2) and mono- and di-methylated lysine-28 of histone H3 (H3K27Me1/2) (Horton et al. 2010, Huang et al. 2010). PHF8 (JHDM1E) catalyses demethylation of mono- or di-methylated lysine-10 of histone H3 (H3K9Me1/2) and mono-methylated lysine-21 of histone H4 (H4K20Me1) (Loenarz et al. 2010, Horton et al. 2010, Feng et al. 2010, Kleine-Kohlbrecher et al. 2010, Fortschegger et al. 2010, Qi et al. 2010, Liu et al. 2010). PHF2 (JHDM1E) catalyses demethylation of mono- or di-methylated lysine-10 of histone H3 (H3K9Me1/2) (Wen et al, 2010, Baba et al. 2011). JMJD6 was initially characterized as an arginine demethylase that catalyses demethylation of mono or di methylated arginine 3 of histone H3 (H3R2Me1/2) and arginine 4 of histone H4 (H4R3Me1/2) (Chang et al. 2007) although it was subsequently also characterized as a lysine hydroxylase (Webby et al. 2009). N.B. The coordinates of post-translational modifications represented and described here follow UniProt standard practice whereby coordinates refer to the translated protein before any further processing. Histone literature typically refers to coordinates of the protein after the initiating methionine has been removed. Therefore the coordinates of post-translated residues in the Reactome database and described here are frequently +1 when compared with the literature."
BMGC_PW0963,BMG_PW3371,,,"Histone acetyltransferases (HATs) involved in histone modifications are referred to as A-type or nuclear HATs. They can be grouped into at least four families based on sequence conservation within the HAT domain: Gcn5/PCAF, MYST, p300/CBP and Rtt109. The p300/CBP and Rtt109 families are specific to metazoans and fungi respectively (Marmorstein & Trievel 2009). Gcn5/PCAF and MYST family members have no significant sequence homology but share a globular alpha/beta fold with a common structure involved in acetyl-Coenzyme A (ACA) binding. Both use a conserved glutamate residue for the acetyl transfer reaction but may not share a common catalytic mechanism (Trievel et al. 1999, Tanner et al. 1999, Yan et al. 2002, Berndsen et al. 2007). The p300/CBP HAT domain has no homology with the other families but some structural conservation within theACA-binding core (Liu et al. 2008). In addition to histone acetylation, members of all 3 human HAT families have been shown to acetylate non-histones (Glozak et al. 2005). HATs and histone deacetylase (HDAC) enzymes generally act not alone but as part of multiprotein complexes. There are numerous examples in which subunits of HAT or HDAC complexes influence their substrate specificity and lysine preference, which in turn, affect the broader functions of these enzymes (Shahbazian & Grunstein 2007). N.B. The coordinates of post-translational modifications represented and described here follow UniProt standard practice whereby coordinates refer to the translated protein before any further processing. Histone literature typically refers to coordinates of the protein after the initiating methionine has been removed. Therefore the coordinates of post-translated residues in the Reactome database and described here are frequently +1 when compared with the literature."
BMGC_PW0964,BMG_PW3372,,,"Arginine methylation is a common post-translational modification; around 2% of arginine residues are methylated in rat liver nuclei (Boffa et al. 1977). Arginine can be methylated in 3 different ways: monomethylarginine (MMA); NG,NG-asymmetric dimethylarginine (ADMA) and NG,N'G-symmetric dimethylarginine (SDMA). The formation of MMA, ADMA and SDMA in mammalian cells is carried out by members of a family of nine protein arginine methyltransferases (PRMTs) (Bedford & Clarke 2009). Type I, II and III PRMTs generate MMA on one of the two terminal guanidino nitrogen atoms. Subsequent generation of asymmetric dimethylarginine (ADMA) is catalysed by the type I enzymes PRMT1, PRMT2, PRMT3, co-activator-associated arginine methyltransferase 1 (CARM1), PRMT6 and PRMT8. Production of symmetric dimethylarginine (SDMA) is catalysed by the type II enzymes PRMT5 and PRMT7. On certain substrates, PRMT7 also functions as a type III enzyme, generating MMA only. PRMT9 activity has not been characterized. No known enzyme is capable of both ADMA and SDMA modifications. Arginine methylation is regarded as highly stable; no arginine demethylases are known (Yang & Bedford 2013). Most PRMTs methylate glycine- and arginine-rich (GAR) motifs in their substrates (Boffa et al. 1977). CARM1 methylates a proline-, glycine- and methionine-rich (PGM) motif (Cheng et al. 2007). PRMT5 can dimethylate arginine residues in GAR and PGM motifs (Cheng et al. 2007, Branscombe et al. 2001). PRMTs are widely expressed and are constitutively active as purified recombinant proteins. However, PRMT activity can be regulated through PTMs, association with regulatory proteins, subcellular compartmentalization and factors that affect enzyme-substrate interactions. The target sites of PRMTs are influenced by the presence of other PTMs on their substrates. The best characterized examples of this are for histones. Histone H3 lysine-19 acetylation (H3K18ac) primes the histone tail for asymmetric dimethylation at arginine-18 (H3R17me2a) by CARM1 (An et al. 2003, Daujat et al. 2002, Yue et al. 2007). H3 lysine-10 acetylation (H3K9ac) blocks arginine-9 symmetric dimethylation (H3R8me2s) by PRMT5 (Pal et al. 2004). H4R3me2a catalyzed by PRMT1 favours subsequent acetylation of the histone H4 tail (Huang et al. 2005). At the same time histone H4 lysine-5 acetylation (H4K5ac) makes the H4R3 motif a better substrate for PRMT5 compared with PRMT1, thereby moving the balance from an activating ADMA mark to a suppressive SDMA mark at the H4R3 motif (Feng et al. 2011). Finally methylation of Histone H3 on arginine-3 (H3R2me2a) by PRMT6 blocks methylation of H3 lysine-5 by the MLL complex (H3K4me3), and vice versa, methylation of H3K4me3 prevents H3R2me2a methylation (Guccione et al. 2007, Kirmizis et al. 2007, Hyllus et al. 2007). N.B. The coordinates of post-translational modifications represented and described here follow UniProt standard practice whereby coordinates refer to the translated protein before any further processing. Histone literature typically refers to coordinates of the protein after the initiating methionine has been removed. Therefore the coordinates of post-translated residues in the Reactome database and described here are frequently +1 when compared with the literature."
BMGC_PW0965,BMG_PW3373,,,"The initial translation products of SUMO1, SUMO2, and SUMO3 are precursors that have extra amino acid residues at the C-terminus (reviewed in Wang and Dasso 2009, Wilkinson and Henley 2010, Hannoun et al. 2010, Gareau and Lima 2010, Hay 2007). SUMO1 has 4 extra residues, SUMO2 has 2 extra residues, and SUMO3 has 11 extra residues. Proteolytic cleavage by SUMO peptidases (SENPs) removes the propeptide and leaves diglycine residues at the C-terminus. Each SENP has distinct preferences for certain SUMOs. SENP1 has highest activity on SUMO1; SENP2 and SENP5 have highest activity on SUMO2 (Shen et al. 2006, Reverter and Lima 2006, Mikolajczyk et al. 2007). SENP1 and SENP2 are predominantly nucleoplasmic (Bailey and O'Hare 2004, Kim et al. 2005, Zhang et al. 2002, Hang and Dasso 2002, Itahana et al. 2006) and SENP5 is predominantly nucleolar (Di Bacco et al. 2006, Gong and Yeh 2006), therefore the processing reactions are believed to occur in the nucleus. The processed SUMO is then activated by formation of a thioester bond with a cysteine residue of an E1 enzyme, UBA2 (SAE2) in a complex with SAE1. SUMO is then transferred from the E1 enzyme to an E2 enzyme, UBC9 (UBE2I)."
BMGC_PW0966,BMG_PW3374,,,"Proteins classified as transcription factors constitute a disproportionate number of SUMOylation targets. In most cases SUMOylation inhibits transcriptional activation, however in some cases such as TP53 (p53) SUMOylation can enhance activation. Inhibition of transcription by SUMOylation may be due to interference with DNA binding, re-localization to inactive nuclear bodies, or recruitment of repressive cofactors such as histone deacetylases (reviewed in Girdwood et al. 2004, Gill 2005)."
BMGC_PW0967,BMG_PW3376,,,"19 WNT proteins have been identified in human cells. The WNTs are members of a conserved metazoan family of secreted morphogens that activate several signaling pathways in the responding cell: the canonical (beta-catenin) WNT signaling cascade and several non-canonical pathways, including the planar cell polarity (PCP), the regulation of intracellular calcium signaling and activation of JNK kinases. WNT proteins exist in a gradient outside the secreting cell and are able to act over both short and long ranges to promote proliferation, changes in cell migration and polarity and tissue homeostasis, among others (reviewed in Saito-Diaz et al, 2012; Willert and Nusse, 2012). The WNTs are ~40kDa proteins with 23 conserved cysteine residues in the N-terminal that may form intramolecular disulphide bonds. They also contain an N-terminal signal sequence and a number of N-linked glycosylation sites (Janda et al, 2012). In addition to being glycosylated, WNTs are also lipid-modified in the endoplasmic reticulum by a WNT-specific O-acyl-transferase, Porcupine (PORCN), contributing to their characteristic hydrophobicity. PORCN-dependent palmitoylation is required for the secretion of WNT as well as its signaling activity, as either depletion of PORCN or mutation of the conserved serine acylation site results in the intracellular accumulation of WNT ligand (Takada et al, 2006; Barrott et al, 2011; Biechele et al, 2011; reviewed in Willert and Nusse, 2012). Secretion of WNT requires a number of other dedicated factors including the sorting receptor Wntless (WLS) (also knownas Evi, Sprinter, and GPR177), which binds WNT and escorts it to the cell surface (Banziger et al, 2006; Bartscherer et al, 2006; Goodman et al, 2006). A WNT-specific retromer containing SNX3 is subsequently required for the recycling of WLS back to the Golgi (reviewed in Herr et al, 2012; Johannes and Wunder, 2011). Once at the cell surface, WNT makes extensive contacts with components of the extracellular matrix such as heparan sulphate proteoglycans (HSPGs) and may be bound by any of a number of regulatory proteins, including WIFs and SFRPs. The diffusion of the WNT ligand may be aided by its packing either into WNT multimers, exosomes or onto lipoprotein particles to shield the hydrophobic lipid adducts from the aqueous extracellular environment (Gross et al, 2012; Luga et al, 2012, Korkut et al, 2009; reviewed in Willert and Nusse, 2012)."
BMGC_PW0968,BMG_PW3377,,,"Eukaryotic DNA is associated with histone proteins and organized into a complex nucleoprotein structure called chromatin. This structure decreases the accessibility of DNA but also helps to protect it from damage. Access to DNA is achieved by highly regulated local chromatin decondensation. The 'building block' of chromatin is the nucleosome. This contains ~150 bp of DNA wrapped around a histone octamer which consists of two each of the core histones H2A, H2B, H3 and H4 in a 1.65 left-handed superhelical turn (Luger et al. 1997, Andrews & Luger 2011). Most organisms have multiple genes encoding the major histone proteins. The replication-dependent genes for the five histone proteins are clustered together in the genome in all metazoans. Human replication-dependent histones occur in a large cluster on chromosome 6 termed HIST1, a smaller cluster HIST2 on chromosome 1q21, and a third small cluster HIST3 on chromosome 1q42 (Marzluff et al. 2002). Histone genes are named systematically according to their cluster and location within the cluster. The 'major' histone genes are expressed primarily during the S phase of the cell cycle and code for the bulk of cellular histones. Histone variants are usually present as single-copy genes that are not restricted in their expression to S phase, contain introns and are often polyadenylated (Old & Woodland 1984). Some variants have significant differences in primary sequence and distinct biophysical characteristics that are thought to alter the properties of nucleosomes. Others localize to specific regions of the genome. Some variants can exchange with pre-existing major histones during development and differentiation, referred to as replacement histones (Kamakaka & Biggins 2005). These variants can become the predominant species in differentiated cells (Pina & Suau 1987, Wunsch et al. 1991). Histone variants may have specialized functions in regulating chromatin dynamics. The H2A histone family has the highest sequence divergence and largest number of variants. H2A.Z and H2A.XH2A are considered 'universal variants', found in almost all organisms (Talbert & Henikoff 2010). Variants differ mostly in the C-terminus, including the docking domain, implicated in interactions with the (H3-H4)x2 tetramer within the nucleosome, and in the L1 loop, which is the interaction interface of H2A-H2B dimers (Bonisch & Hake 2012). Canonical H2A proteins are expressed almost exclusively during S-phase. There are several nearly identical variants (Marzluff et al. 2002). No functional specialization of these canonical H2A isoforms has been demonstrated (Bonisch & Hake 2012). Reversible histone modifications such as acetylation and methylation regulate transcription from genomic DNA, defining the 'readability' of genes in specific tissues (Kouzarides 2007, Marmorstein & Trievel 2009, Butler et al. 2012). N.B. The coordinates of post-translational modifications represented here follow Reactome standardized naming, which includes the UniProt standard practice whereby coordinates refer to the translated protein before any further processing. Histone literature typically refers to coordinates of the protein after the initiating methionine has been removed; therefore the coordinates of post-translated histone residues described here are frequently +1 when compared with the literature. For more information on Reactome's standards for naming pathway events, the molecules that participate in them and representation of post-translational modifications, please refer to Naming Conventions on the Reactome Wiki or Jupe et al. 2014."
BMGC_PW0969,BMG_PW3380,,,"TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) are central regulators of type-I interferon induction during bacterial or viral infection. TBK1 was found to form complexes with distinct scaffolding proteins that appeared to target TBK1 to different subcellular compartments [Hemmi H et al 2004; Oganesyan G et al 2006; Chariot A et al 2002; Huang J et al 2005]. STING interacted with both TBK1 and IRF3. Once STING is stimulated, its C-terminus served as a signaling scaffold to recruit IRF3 anhd TBK1, which led to TBK1-dependent phosphorylation of IRF3. Phosphorylation of IRF3 promoted its dimerization and translocation to the nucleus, where it triggered the transcription of interferon stimulated genes (ISGs) (Tanaka Y and Chen ZJ 2012)."
BMGC_PW0970,BMG_PW3382,,,"Transient receptor potential (TRP) channel proteins were first discovered in Drosophila melanogaster and have many homologues in other species including humans. TRPs form cationic channels that can detect sensory stimuli such as temperature, pH or oxidative stress and transduce that into either electrical (change in membrane potential) or chemical signals (change in intracellular Ca2+ concentration). In humans, there are 28 TRP genes arranged into 6 subfamilies; TRPA, TRPC, TRPM, TRPML, TRPP, and TRPV (Wu et al. 2010). Each TRP channel subunit consists of six putative transmembrane-spanning segments (S1-S6) with a pore-forming loop between S5 and S6. These subunits assemble into tetramers to form functional channels. All functionally characterized TRP channels are permeable to Ca2+ except TRMP4 and 5 which are only permeable to monovalent cations such as Na+ (Latorre et al. 2009). Most TRPs can cause channelopathies which are risk factors for many disease states (Nilius & Owsianik 2010)."
BMGC_PW0971,BMG_PW3384,,,"Vitamins are essential nutrients, required in small amounts from the diet for the normal growth and development of a multicellular organism. Where there is vitamin deficiency, either by poor diet or a defect in metabolic conversion, diseases called Avitaminoses occur. Currently, cobalamin (Cbl, vitamin B12) metabolic defects are described below (Chapter 155 in The Metabolic and Molecular Bases of Inherited Disease, 8th ed, Scriver et al. 2001)"
BMGC_PW0972,BMG_PW3385,,,"Reactive oxygen species such as superoxide (O2.-), peroxides (ROOR), singlet oxygen, peroxynitrite (ONOO-), and hydroxyl radical (OH.) are generated by cellular processes such as respiration (reviewed in Murphy 2009, Brand 2010) and redox enzymes and are required for signaling yet they are damaging due to their high reactivity (reviewed in Imlay 2008, Buettner 2011, Kavdia 2011, Birben et al. 2012, Ray et al. 2012). Aerobic cells have defenses that detoxify reactive oxygen species by converting them to less reactive products. Superoxide dismutases convert superoxide to hydrogen peroxide and oxygen (reviewed in Fukai and Ushio-Fukai 2011). Catalase and peroxidases then convert hydrogen peroxide to water. Humans contain 3 superoxide dismutases: SOD1 is located in the cytosol and mitochondrial intermembrane space, SOD2 is located in the mitochondrial matrix, and SOD3 is located in the extracellular region. Superoxide, a negative ion, is unable to easily cross membranes and tends to remain in the compartment where it was produced. Hydrogen peroxide, one of the products of superoxide dismutase, is able to diffuse across membranes and pass through aquaporin channels. In most cells the primary source of hydrogen peroxide is mitochondria and, once in the cytosol, hydrogen peroxide serves as a signaling molecule to regulate redox-sensitive proteins such as transcription factors, kinases, phosphatases, ion channels, and others (reviewed in Veal and Day 2011, Ray et al. 2012). Hydrogen peroxide is decomposed to water by catalase, decomposed to water plus oxidized thioredoxin by peroxiredoxins, and decomposed to water plus oxidized glutathione by glutathione peroxidases (Presnell et al. 2013)."
BMGC_PW0973,BMG_PW3386,,,"Nuclear envelope breakdown in mitosis involves permeabilization of the nuclear envelope through disassembly of the nuclear pore complex (NPC) (reviewed by Guttinger et al. 2009). Nucleoporin NUP98, located at both the cytoplasmic and the nucleoplasmic side of the NPC (Griffis et al. 2003), and involved in the formation of the transport barrier through its FG (phenylalanine glycine) repeats that protrude into the central cavity of the NPC (Hulsmann et al. 2012), is probably the first nucleoporin that dissociates from the NPC at the start of mitotic NPC disassembly (Dultz et al. 2008). NUP98 dissociation is triggered by phosphorylation. Phosphorylation of NUP98 by CDK1 and NIMA family kinases NEK6 and/or NEK7 is needed for NUP98 dissociation from the NPC (Laurell et al. 2011). While the phosphorylation of NUP98 by CDK1 and NEK6/7 is likely to occur simultaneously, CDK1 and NEK6/7-mediated phosphorylations are shown as separate events, for clarity purposes."
BMGC_PW0974,BMG_PW3387,,,"SMAD4 was identified as a gene homozygously deleted in ~30% of pancreatic cancers and was named DPC4 (DPC stands for deleted in pancreatic cancer). SMAD4 maps to the chromosomal band 18q21.1, and about 90% of pancreatic carcinomas show allelic loss at chromosomal arm 18q (Hahn et al. 1996), while ~50% of pancreatic cancers show some alteration of the SMAD4 gene (reviewed by Schutte et al. 1999). Based on COSMIC database (Catalogue Of Somatic Mutations In Cancer) (Forbes et al. 2011), mutations in the coding sequence of SMAD4 gene are frequently found in pancreatic cancer, biliary duct carcinoma and colorectal cancer (reviewed by Schutte et al. 1999). Germline SMAD4 mutations are the cause of juvenile polyposis, an autosomal dominant disease that predisposes affected individuals to hamartomatous polyps and gastrointestinal cancer (Howe et al. 1998). Homozygous Smad4 loss is embryonic lethal in mice (Takaku et al. 1998). Smad4 +/- heterozygotes appear normal but develop intestinal polyps between 6 and12 months of age and these polyps can progress to cancer. Loss of the remaining wild-type Smad4 allele is detectable only at later stages of tumor progression in Smad4+/- mice (Xu et al. 2000). Compound Apc+/-;Smad4+/- mice develop malignant tumors from intestinal polyps more rapidly than Apc+/- mice (Takaku et al. 1998). SMAD4 coding sequence mutations are most frequently found in the MH2 domain and impair the formation of SMAD4 heterotrimers with phosphorylated SMAD2 and SMAD3 (Shi et al. 1997, Fleming et al. 2013), thereby impairing SMAD4:SMAD2/3 heterotrimer-mediated transcriptional regulation of TGF-beta responsive genes. MH2 domain is also involved in the formation of SMAD4 homotrimers which may play a role in SMAD4 protein stability (Shi et al. 1997). Coding sequence mutations are also found in the MH1 domain of SMAD4. MH1 domain is involved in DNA binding (Dai et al. 1999) and it is also involved in the formation of SMAD4 homotrimers (Hata et al. 1997)."
BMGC_PW0975,BMG_PW3388,,,"Loss-of-function of SMAD2 and SMAD3 in cancer occurs less frequently than the loss of SMAD4 function and was studied in most detail in colorectal cancer (Fleming et al. 2013). Similarly to SMAD4, coding sequence mutations in SMAD2 and SMAD3 in cancer cluster in the MH2 domain, involved in the formation of transcriptionally active heterotrimers with SMAD4. Another region of SMAD2 and SMAD3 that is frequently mutated in cancer is the phosphorylation motif Ser-Ser-X-Ser at the very C-terminus (Fleming et al. 2013). The phosphorylation of this conserved motif by the activated TGF-beta receptor complex is an essential step in SMAD2 and SMAD3 activation and a prerequisite for the formation of heterotrimers with SMAD4 (Chacko et al. 2001, Chacko et al. 2004). Smad2 knockout mice die at embryonic day 8.5, with impaired visceral endoderm function and deficiency in mesoderm formation. Smad2+/- heterozygotes appear normal and are fertile (Hamamoto et al. 2002). While polyps of compound Smad2+/-;Apc+/- mice show no difference in the number, size or histopathology from the polyps of Apc+/- mice (Takaku et al. 2002, Hamamoto et al. 2002), Smad2+/-;Apc+/- mice develop extremely large intestinal tumors and multiple invasive cancers not observed in Apc+/- mice. Therefore, loss of Smad2 does not contribute to initiation of intestinal tumorigenesis, but accelerates malignant progression (Hamamoto et al. 2002). Smad3 knockout mice are viable and fertile but die between 4 and 6 months of age from colorectal adenocarcinoma (Zhu et al. 1998), indicating that the loss of Smad3 initiates intestinal tumorigenesis."
BMGC_PW0976,BMG_PW3389,,,"Signaling by the TGF-beta receptor complex is tumor suppressive, as it inhibits cell growth and promotes cell differentiation and apoptosis (Shipley et al. 1986, Hannon et al. 1994, Datto et al. 1995, Chen et al. 2002, Azar et al. 2009). TGF-beta signaling is frequently impaired in cancer, mostly through SMAD4 gene deletion or loss-of-function mutations (described in the pathway Loss of Function of SMAD4 in Cancer), which are especially frequent in pancreatic cancer (Hahn et al. 1996, Shi et al. 1997, Fleming et al. 2013). Signaling by TGF-beta receptor complex can also be disrupted by loss-of-function mutations in SMAD2 and SMAD3 (Fleming et al. 2013), as described in the pathway Loss of Function of SMAD2/SMAD3 in Cancer, or loss-of-function mutations in TGFBR2 (TGF-beta receptor II) (Markowitz et al. 1995, Garrigue-Antar et al. 1995, Parsons et al. 1995, Grady et al. 1999), as described in the pathway Loss of Function of TGFBR2 in Cancer, or TGFBR1 (TGF-beta receptor I) (Chen et al. 1998, Chen et al. 2001, Goudie et al. 2011), as described in the pathway Loss of Function of TGFBR1 in Cancer. In advanced cancer, signaling by TGF-beta may be tumor promoting, as it induces epithelial-to-mesenchymal transition (EMT), thereby increasing invasiveness (Cui et al. 1996, Guasch et al. 2007, reviewed by Heldin et al. 2012)."
BMGC_PW0977,BMG_PW3390,,,"The conserved phosphorylation motif Ser-Ser-X-Ser at the C-terminus of SMAD2 and SMAD3 is subject to disruptive mutations in cancer. The last two serine residues in this conserved motif, namely Ser465 and Ser467 in SMAD2 and Ser423 and Ser425 in SMAD3, are phosphorylated by the activated TGF beta receptor complex (Macias Silva et al. 1996, Nakao et al. 1997). Once phosphorylated, SMAD2 and SMAD3 form transcriptionally active heterotrimers with SMAD4 (Chacko et al. 2001, Chacko et al. 2004). Phosphorylation motif mutants of SMAD2 and SMAD3 cannot be activated by the TGF-beta receptor complex either because serine residues are substituted with amino acid residues that cannot be phosphorylated or because the phosphorylation motif is deleted from the protein sequence or truncated (Fleming et al. 2013)."
BMGC_PW0978,BMG_PW3391,,,"The MH2 domain of SMAD4 is the most frequently mutated SMAD4 region in cancer. MH2 domain mutations result in the loss of function of SMAD4 by abrogating the formation of transcriptionally active heterotrimers of SMAD4 and TGF-beta receptor complex-activated R-SMADs - SMAD2 and SMAD3 (Shi et al. 1997, Chacko et al. 2001, Chacko et al. 2004, Fleming et al. 2013). The hotspot MH2 domain amino acid residues that are targeted by missense mutations are Asp351 (D351), Pro356 (P356) and Arg361 (R361). These three hotspot residues map to the L1 loop which is conserved in SMAD2 and SMAD3 and is involved in intermolecular interactions that contribute to the formation of SMAD heterotrimers and homotrimers (Shi et al. 1997, Fleming et al. 2013). Other frequently mutated residues in the MH2 domain of SMAD4 - Ala406 (A406), Lys428 (K428) and Arg515 (R515) - are involved in binding the phosphorylation motif (Ser-Ser-X-Ser) of SMAD2 and SMAD3, with Arg515 in the L3 loop being critical for this interaction (Chacko et al. 2001, Chacko et al. 2004, Fleming et al. 2013)."
BMGC_PW0979,BMG_PW3392,,,"Mutations in the MH2 domain of SMAD2 and SMAD3 affect their ability to form heterotrimers with SMAD4, thereby impairing TGF-beta signaling (Fleming et al. 2013). The SMAD2 and SMAD3 MH2 domain residues most frequently targeted by missense mutations are those that are homologous to SMAD4 MH2 domain residues shown to be involved in the formation of SMAD heterotrimers. Asp300 of SMAD2 and Asp258 of SMAD3 correspond to the frequently mutated Asp351 of SMAD4. Pro305 of SMAD2 corresponds to the frequently mutated Pro356 of SMAD4, while Ala354 of SMAD2 corresponds to Ala406 of SMAD4. Arg268 of SMAD3 corresponds to the frequently mutated Arg361 of SMAD4. SMAD2 and SMAD3 MH2 domain mutations have been examined in most detail in colorectal cancer (Fleming et al. 2013)."
BMGC_PW0980,BMG_PW3405,,,"c-FLIP proteins (CASP8 and FADD-like apoptosis regulators or c-FLICE inhibitory proteins) are death effector domain (DED)-containing proteins that are recruited to the death-inducing signaling complex (DISC) to regulate activation of caspases-8. Three out of 13 distinct spliced variants of c-FLIP had been found to be expressed at the protein level, the 26 kDa short form FLIP(S), the 24 kDa form FLIP(R), and the 55 kDa long form FLIP(L) (Irmler M et al. 1997; Shu HB et al. 1997; Srinivasula SM et al. 1997; Scaffidi C et al. 1999; Golks A et al. 2005; Haag C et al. 2011) All c-FLIP proteins carry two DEDs at their N termini, which can bind FADD and procaspase-8. In addition to two DEDs, FLIP(L) contains a large (p20) and a small (p12) caspase-like domain without catalytic activity. FLIP(S) and FLIP(R) consist of two DEDs and a small C terminus. Depending on its level of expression FLIP(L) may function as an anti-apoptotic or pro-apoptotic factor, while FLIP(S) and FLIP(R) protect cells from apoptosis by blocking the processing of caspase-8 at the receptor level (Scaffidi C et al. 1999; Golks A et al. 2005; Toivonen HT et al. 2011; Fricker N et al. 2010)."
BMGC_PW0981,BMG_PW3406,,,"The ability of HSF1 to respond to cellular stresses is under negative regulation by chaperones, modulation of nucleocytoplasmic shuttling, post-translational modifications and transition from monomeric to trimeric state."
BMGC_PW0982,BMG_PW3408,,,"Heat shock factor 1 (HSF1) is a transcription factor that activates gene expression in response to a variety of stresses, including heat shock, oxidative stress, as well as inflammation and infection (Shamovsky I and Nudler E 2008; Akerfelt et al. 2010; Bjork and Sistonen 2010; Anckar and Sistonen 2011). HSF1 is constitutively present in the cell. In the absence of stress HSF1 is found in both the cytoplasm and the nucleus as an inactive monomer (Sarge KD et al. 1993; Mercier PA et al. 1999; Vujanac M et al. 2005). A physical or chemical proteotoxic stress rapidly induces HSF1 activation, which occurs through a multi?step process, involving HSF1 monomer-to-homotrimer transition, nuclear accumulation, and binding to a promoter element, called the heat shock element (HSE), which leads to the increase in the stress-inducible gene expression (Sarge KD et al. 1993; Baler R et al. 1998; Sonna LA et al. 2002; Shamovsky I and Nudler E 2008; Sakurai H and Enoki Y 2010; Herbomel G et al. 2013). Depending on the type of stress stimulus, the multiple events associated with HSF1 activation might be affected differently (Holmberg CI et al 2000; Bjork and Sistonen 2010)."
BMGC_PW0983,BMG_PW3409,,,"Attenuation of the heat shock transcriptional response occurs during continuous exposure to intermediate heat shock conditions or upon recovery from stress (Abravaya et al. 1991). The attenuation phase of HSF1 cycle involves the transcriptional silencing of HSF1 bound to HSE, the release of HSF1 trimers from HSE and dissociation of HSF1 trimers to monomers. HSF1-driven heat stress associated transcription was shown to depend on inducible and reversible acetylation of HSF1 at Lys80, which negatively regulates DNA binding activity of HSF1 (Westerheide SD et al. 2009). In addition, the attenuation of HSF1 activation takes place when enough HSP70/HSP40 is produced to saturate exposed hydrophobic regions of proteins damaged as a result of heat exposure. The excess HSP70/HSP40 binds to HSF1 trimer, which leads to its dissociation from the promoter and conversion to the inactive monomeric form (Abravaya et al. 1991; Shi Y et al. 1998). Interaction of HSP70 with the transcriptional corepressor repressor element 1-silencing transcription factor corepressor (CoREST) assists in terminating heat-shock response (Gomez AV et al. 2008). HSF1 DNA-binding and transactivation activity were also inhibited upon interaction of HSF1-binding protein (HSBP1) with active trimeric HSF1(Satyal SH et al. 1998)."
BMGC_PW0984,BMG_PW3410,,,"Acquisition of DNA binding activity by HSF1 is necessary but insufficient for transcriptional activation (Cotto JJ et al. 1996; Trinklein ND et al. 2004). In addition to having a sequence-specific DNA binding domain, HSF1 contains a C-terminal region which is involved in activating the transcription of the target genes (Green M et al. 1995). However, the transactivating ability of the transactivation domain itself is not stress sensitive. Rather, it's controled by a regulatory domain of HSF1 (amino acids 221-310), which represses the transactivating ability under normal physiological conditions (Green M et al. 1995; Zuo J et al. 1995; Newton EM et al. 1996). The HSF1 transactivation domain can be divided into two distinct regions, activation domain 1 (AD1) and activation domain 2 (AD2) (Brown SA et al. 1998). AD1 and AD2 each contain residues that are important for both transcriptional initiation and elongation. Mutations in acidic residues in both AD1 and AD2 preferentially affect the ability of HSF1 to stimulate transcriptional initiation, while mutations in phenylalanine residues preferentially affect stimulation of elongation (Brown SA et al. 1998). Activation of the DNA-bound but transcriptionally incompetent HSF1 is thought to occur upon stress induced HSF1 phosphorylation at several serine residues (Ding XZ et al. 1997; Holmberg CI et al. 2001; Guettouche T et al. 2005). In cells exposed to heat, acquisition of HSE DNA-binding activity was observed to precede phosphorylation of HSF1 (Cotto JJ et al. 1996; Kline MP & Morimoto RI 1997). While there is a sufficient evidence to suggest that phosphorylation of HSF1 is essential to modulate HSF1 transactiviting capacity, mechanisms behind stress stimuli and kinases/phosphatases involved have not been clearly established."
BMGC_PW0985,BMG_PW3412,,,"Defects in HLCS causes holocarboxylase synthetase deficiency (HLCS deficiency aka early onset multiple carboxylase deficiency; MIM:253270). HLCS deficiency is an autosomal recessive disorder whereby deficient HLCS activity results in reduced activity of all five biotin-dependent carboxylases. Symptoms include metabolic acidosis, organic aciduria, lethargy, hypotonia, convulsions and dermatitis (Suzuki et al. 2005). Patients can present symptoms shortly after birth to up to early childhood and will be prescribed oral biotin supplements, typically 10-20 mg daily. Two classes of HLCS deficiency have been reported depending on whether patients respond to biotin therapy. Most patients respond favourably to treatment and show complete reversal of biochemical and clinical symptoms (Morrone et al. 2002, Dupuis et al. 1999). Here mutations in the HLCS active site cause a reduced affinity for biotin that can be overcome by pharmacological doses of the vitamin (Pendini et al. 2008). Patients who display incomplete responsiveness to biotin therapy have a poor long-term prognosis (Bailey et al. 2008). Here mutations that reside outside of the enzyme's active site have no effect on biotin binding but do compromise the protein-protein interaction between the HLCS and its substrates, resulting in reduced biotinylation of all five carboxylases thus reducing their enzymatic activity (Mayende et al. 2012)."
BMGC_PW0986,BMG_PW3413,,,"COP1 is one of several E3 ubiquitin ligases responsible for the tight regulation of p53 abundance. Following DNA damage, COP1 dissociates from p53 and is inactivated by autodegradation via a pathway involving ATM phosphorylation of COP1 on Ser(387), autoubiquitination and proteasome mediated degradation. Destruction of COP1 results in abrogation of the ubiquitination and degradation of p53 (Dornan et al., 2006)."
BMGC_PW0987,BMG_PW3414,,,"THE NOTCH-HLH TRANSCRIPTION PATHWAY: Notch signaling was first identified in Drosophila, where it has been studied in detail at the genetic, molecular, biochemical and cellular levels (reviewed in Justice, 2002; Bray, 2006; Schweisguth, 2004; Louvri, 2006). In Drosophila, Notch signaling to the nucleus is thought always to be mediated by one specific DNA binding transcription factor, Suppressor of Hairless. In mammals, the homologous genes are called CBF1 (or RBPJkappa), while in worms they are called Lag-1, so that the acronym ""CSL"" has been given to this conserved transcription factor family. There are at least two human CSL homologues, which are now named RBPJ and RBPJL. CSL is an example of a bifunctional DNA-binding transcription factor that mediates repression of specific target genes in one context, but activation of the same targets in another context. This bifunctionality is mediated by the association of specific Co-Repressor complexes vs. specific Co-Activator complexes in different contexts, namely in the absence or presence of Notch signaling. In Drosophila, Su(H) represses target gene transcription in the absence of Notch signaling, but activates target genes during Notch signaling. At least some of the mammalian CSL homologues are believed also to be bifunctional, and to mediate target gene repression in the absence of Notch signaling, and activation in the presence of Notch signaling. Notch Co-Activator and Co-Repressor complexes: This repression is mediated by at least one specific co-repressor complexes (Co-R) bound to CSL in the absence of Notch signaling. In Drosophila, this co-repressor complex consists of at least three distinct co-repressor proteins: Hairless, Groucho, and dCtBP (Drosophila C-terminal Binding Protein). Hairless has been show to bind directly to Su(H), and Groucho and dCtBP have been shown to bind directly to Hairless (Barolo, 2002). All three of the co-repressor proteins have been shown to be necessary for proper gene regulation during Notch signaling in vivo (Nagel, 2005). In mammals, the same general pathway and mechanisms are observed, where CSL proteins are bifunctional DNA binding transcription factors (TFs), that bind to Co-Repressor complexes to mediate repression in the absence of Notch signaling, and bind to Co-Activator complexes to mediate activation in the presence of Notch signaling. However, in mammals, there may be multiple co-repressor complexes, rather than the single Hairless co-repressor complex that has been observed in Drosophila. During Notch signaling in all systems, the Notch transmembrane receptor is cleaved and the Notch intracellular domain (NICD) translocates to the nucleus, where it there functions as a specific transcription co-activator for CSL proteins. In the nucleus, NICD replaces the Co-R complex bound to CSL, thus resulting in de-repression of Notch target genes in the nucleus. Once bound to CSL, NICD and CSL proteins recruit an additional co-activator protein, Mastermind, to form a CSL-NICD-Mam ternary co-activator (Co-A) complex. This Co-A complex was initially thought to be sufficient to mediate activation of at least some Notch target genes. However, there now is evidence that still other co-activators and additional DNA-binding transcription factors are required in at least some contexts (reviewed in Barolo, 2002). Mammalian CSL Corepressor Complexes: In the absence of activated Notch signaling, DNA-bound CSL proteins recruit a corepressor complex to maintain target genes in the repressed state until Notch is specifically activated. The mammalian corepressor complexes include NCOR complexes, but may also include additional corepressor proteins, such as SHARP (reviewed in Mumm, 2000 and Kovall, 2007). The exact composition of the CSL NCOR complex is not known, but in other pathways the ""core"" NCOR corepressor complex includes at least one NCOR protein (NCOR1, NCOR2, CIR), one Histone Deacetylase protein (HDAC1, HDAC2, HDAC3, etc), and one TBL1 protein (TBL1X, TBL1XR1) (reviewed in Rosenfeld, 2006). In some contexts, the core NCOR corepressor complex may also recruit additional corepressor proteins or complexes, such as the SIN3 complex, which consists of SIN3 (SIN3A, SIN3B), and SAP30, or other SIN3-associated proteins. An additional CSL - NCOR binding corepressor, SHARP, may also contribute to the CSL corepressor complex in some contexts (Oswald, 2002). The CSL corepressor complex also includes a bifunctional cofactor, SKIP, that is present in both CSL corepressor complexes and CSL coactivator complexes, and may function in the binding of NICD and displacement of the corepressor complex during activated Notch signaling (Zhou, 2000). Mammalian CSL Coactivator Complexes: Upon activation of Notch signaling, cleavage of the transmembrane Notch receptor releases the Notch Intracellular Domain (NICD), which translocates to the nucleus, where it binds to CSL and displaces the corepressor complex from CSL (reviewed in Mumm, 2000 and Kovall, 2007). The resulting CSL-NICD ""binary complex"" then recruits an additional coactivator, Mastermind (Mam), to form a ternary complex. The ternary complex then recruits additional, more general coactivators, such as CREB Binding Protein (CBP), or the related p300 coactivator, and a number of Histone Acetytransferase (HAT) proteins, including GCN5 and PCAF (Fryer, 2002). There is evidence that Mam also can subsequently recruit specific kinases that phosphorylate NICD, to downregulate its function and turn off Notch signaling (Fryer, 2004). Combinatorial Complexity in Transcription Cofactor Complexes: HDAC9 has at least 7 splice isoforms, with some having distinct interaction and functional properties. Isoforms 6 and 7 interact with NCOR1. Isoforms 1 and 4 interact with MEF2 (Sparrow, 1999), which is a specific DNA-binding cofactor for a subset of HLH proteins. Isoform 3 interacts with both NCOR1 and MEF2. Although many HDACs only have one or two isoforms, this complexity for HDAC9 illustrates the level of transcript complexity and functional specificity that such ""general"" transcriptional cofactors can have."
BMGC_PW0988,BMG_PW3415,,,"Polyamines increase the production of antizyme (AZ). The carboxy-terminal half of antizyme interacts with ODC, generating an inactive AZ:ODC heterodimer complex. A carboxy-terminal domain of ODC is exposed only within the heterodimer, and is the target for subsequent degradation. A domain within the amino-terminal portion of antizyme provides a function needed for efficient degradation of ODC by the proteasome. The proteasome cycle starts with the processing of AZ:ODC, sequestering ODC and then degrading it to peptides but releasing AZ. AZ participates in additional rounds of binding and degradation. Antizyme-mediated inhibition and destruction of ODC reduces synthesis of polyamines. Additionally, antizyme also inhibits polyamine transport into the cell. Antizyme production is reduced, completing the regulatory circuit (Coffino, 2001). The following illustration is adapted from a minireview by Pegg, 2006; J. Biol. Chem., Vol. 281, Issue 21, 14529-14532."
BMGC_PW0989,BMG_PW3416,,,"The iodothyronine deiodinases (DIO) are dimeric, membrane-bound enzymes that regulate the activity of thyroid hormone by removal of specific iodines from the precursor T4. There are three types of DIOs in humans; types I, II and III (D1, D2 and D3 respectively) which are proteins of about 250 residues that contain a selenocysteine at their active site. Signaling by thyroid hormone can change in individual tissues by this activation or inactivation process, even when serum concentrations of the hormone remain normal. Generally, cell types express just one type of DIO at any one time. The exception is the pituitary gland which expresses all three."
BMGC_PW0990,BMG_PW3418,,,"Apoptotic cells show dramatic rearrangements of tight junctions, adherens junctions, and desmosomes (Abreu et al., 2000). Desmosome-specific members of the cadherin superfamily of cell adhesion molecules including desmoglein-3, plakophilin-1 and desmoplakin are cleaved by caspases after onset of apoptosis (Weiske et al., 2001). Cleavage results in the disruption of the desmosome structure and thus contributes to cell rounding and disintegration of the intermediate filament system (Weiske et al., 2001)."
BMGC_PW0991,BMG_PW3419,,,"Amino acid transport across plasma membranes is critical to the uptake of these molecules from the gut, to their reabsortion in the kidney proximal tubulues, and to their distribution to cells in which they are required for the synthesis of proteins and of amino acid derived small molecules such as neurotransmitters. Physiological studies have defined 18 ""systems"" that mediate amino acid transport, each characterized by its amino acid substrates, as well as its pH sensitivity and its association (or not) with ion transport. More recently, molecular cloning studies have allowed the identification of the plasma membrane transport proteins that mediate these reactions. Amino acid uptake mediated by 17 of these transporters is annotated here (Broer 2008)."
BMGC_PW0992,BMG_PW3420,,,Activated caspases cleave nuclear lamins causing the irreversible breakdown of the nuclear lamina.
BMGC_PW0993,BMG_PW3421,,,"Integrins are a major family of cell surface receptors that modulate cell adhesion, migration, proliferation and survival through interaction with the extracellular matrix (ECM) and the actin cytoskeleton. Integrins are type 1 transmembrane proteins that exist at the cell surface as heterodimers of alpha and beta subunits, of which there are 18 and 8 different isoforms, respectively, in human cells. In addition to their mechanical role in mediating contact between the ECM and the cytoskeleton, integrins also modulate intracellular signaling pathways governing cytoskeletal rearrangements and pro-survival and mitogenic signaling (reviewed in Hehlgans et al, 2007; Harburger and Calderwood, 2009; Ata and Antonescu, 2017). In this pathway, we describe signaling through integrin alphaIIb beta3 as a representative example. At the sites of vascular injury bioactive molecules such as thrombin, ADP, collagen, fibrinogen and thrombospondin are generated, secreted or exposed. These stimuli activate platelets, converting the major platelet integrin alphaIIbbeta3 from a resting state to an active conformation, in a process termed integrin priming or 'inside-out signalling'. Integrin activation refers to the change required to enhance ligand-binding activity. The activated alphaIIbbeta3 interacts with the fibrinogen and links platelets together in an aggregate to form a platelet plug. AlphaIIbbeta3 bound to fibrin generates more intracellular signals (outside-in signalling), causing further platelet activation and platelet-plug retraction. In the resting state the alpha and beta tails are close together. This interaction keeps the membrane proximal regions in a bent conformation that maintains alphaIIbbeta3 in a low affinity state. Integrin alphaIIbbeta3 is released from its inactive state by interaction with the protein talin. Talin interacts with the beta3 cytoplasmic domain and disrupts the salt bridge between the alpha and beta chains. This separation in the cytoplasmic regions triggers the conformational change in the extracellular domain that increases its affinity to fibrinogen. Much of talin exists in an inactive cytosolic pool, and the Rap1 interacting adaptor molecule (RIAM) is implicated in talin activation and translocation to beta3 integrin cytoplasmic domain."
BMGC_PW0994,BMG_PW3422,,,Integrin signaling is linked to the MAP kinase pathway by recruiting Grb2 to the FADK1/SRC activation complex.
BMGC_PW0995,BMG_PW3423,,,"A number of genetic disorders are caused by mutations in the genes encoding glycosyltransferases and sulfotransferases, enzymes responsible for the synthesis of glycosaminoglycans (GAGs) as well as hexosaminidase degradation of GAGs (Mizumoto et al. 2013)."
BMGC_PW0996,BMG_PW3424,,,"Ehlers–Danlos syndrome (EDS) is a group of inherited connective tissue disorders, caused by a defect in the synthesis of collagen types I or III. Abnormal collagen renders connective tissues more elastic. The severity of the mutation can vary from mild to life-threatening. There is no cure and treatment is supportive, including close monitoring of the digestive, excretory and particularly the cardiovascular systems. Defective B4GALT7, a galactosyltransferase important in proteoglycan synthesis, causes the progeroid variant of EDS (MIM:130070). Features include an aged appearance, developmental delay, short stature, generalized osteopenia, defective wound healing, hypermobile joints, hypotonic muscles, and loose but elastic skin (Okajima et al. 1999)."
BMGC_PW0997,BMG_PW3427,,,"Galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferases1, 2 and 3 (B3GAT1-3) are involved in forming the linker tetrasaccharide present in heparan sulfate and chondroitin sulfate. Defects in B3GAT3 cause multiple joint dislocations, short stature, craniofacial dysmorphism, and congenital heart defects (JDSSDHD; MIM:245600). This is an autosomal recessive disease characterized by dysmorphic facies, elbow, hip and knee dislocations, clubfeet, short stature and cardiovascular defects (Steel & Kohl 1972, Bonaventure et al. 1992, Baasanjav et al. 2011). JDSSDHD has phenotypic similarities to Larsen syndrome (Larsen et al. 1950)."
BMGC_PW0998,BMG_PW3428,,,"Carbohydrate sulfotransferase 3 (CHST3) transfers sulfate (SO4(2-)) to position 6 of N-acetylgalactosamine (GalNAc) residues of chondroitin-containg proteins resulting in chondroitin sulfate (CS), the predominant glycosaminoglycan present in cartilage. Defects in CHST3 result in spondyloepiphyseal dysplasia with congenital joint dislocations (SEDCJD; MIM:143095), a bone dysplasia clinically characterized by severe progressive kyphoscoliosis (abnormal curvature of the spine), arthritic changes with joint dislocations and short stature in adulthood (Unger et al. 2010)."
BMGC_PW0999,BMG_PW3429,,,"Carbohydrate sulfotransferase 14 (CHST14 also known as D4ST-1) mediates the transfer of sulfate to position 4 of further N-acetylgalactosamine (GalNAc) residues of dermatan sulfate (DS). Defects in CHST14 cause Ehlers-Danlos syndrome, musculocontractural type (MIM:601776). The Ehlers-Danlos syndromes (EDS) are a group of connective tissue disorders that share common features such as skin hyperextensibility, articular hypermobility and tissue fragility (Beighton et al. 1998). The musculocontractural form of EDS (MIM:601776) include distinctive characteristics such as craniofacial dysmorphism, congenital contractures of fingers and thumbs, clubfeet, severe kyphoscoliosis and muscular hypotonia (Malfait et al. 2010)."
BMGC_PW1000,BMG_PW3430,,,"Chondroitin sulfate synthases (CHSY) are involved in the synthesis of chondroitin sulfate, adding alternatingly glucuronate (GlcA) and N-acetylgalactosamine (GalNAc) to the growing chondroitin polymer (Mizumoto et al. 2013). Defects in CHSY1 cause temtamy preaxial brachydactyly syndrome (TPBS; MIM:605282), a syndrome characterized by multiple congenital anomalies, mental retardation, sensorineural deafness, growth retardation and bilateral symmetric digital anomalies mainly in the form of preaxial brachydactyly (literally, shortness of fingers and toes) and hyperphalangism (Temtamy et al. 1998, Race et al. 2010, Tian et al. 2010)."
BMGC_PW1001,BMG_PW3431,,,"Loss-of-function of transforming growth factor-beta receptor II (TGFBR2) is most prevalent in colorectal cancer. Over 60% of colorectal cancers with microsatellite instability (MSI) harbor inactivating mutations in both alleles of TGFBR2, mostly 1 or 2 bp deletions in the 10 bp adenine repeat that codes for three lysine residues in the extracellular domain of TGFBR2. These small deletions result in a frameshift and a premature stop codon (Markowitz et al. 1995). TGFBR2 kinase domain (KD) mutations are found in ~20% of microsatellite stable (MSS) colorectal cancers and these are mostly missense mutations that results in substitution of conserved amino acids in the kinase domain (Grady et al. 1999), likely impairing the catalytic activity of TGFBR2 KD mutants. The silencing of TGFBR2 gene via promoter methylation has been reported in B-cell lymphoma (Chen et al. 2007). Knockout of murine Tgfbr2 in colonic epithelium promotes azoxymethane-induced colon cancer formation (Biswas et al. 2004) and increases the number of adenomas and adenocarcinomas in Apc+/- mice (Munoz et al. 2006)."
BMGC_PW1002,BMG_PW3432,,,The short adenine repeat in the coding sequence of TGF-beta receptor II (TGFBR2) gene is frequently targeted by loss-of-function frameshift mutations in colon cancers with microsatellite instability (MSI). The 1- or 2-bp deletions in the adenine stretch of TGFBR2 cDNA introduce a premature stop codon that leads to degradation of the majority of mutant transcripts through nonsense-mediated decay or to production of a truncated TGFBR2 that cannot be presented on the cell surface. Cells that harbor TGFBR2 MSI frameshift mutations are resistant to TGF-beta (TGFB1)-mediated growth inhibition.
BMGC_PW1003,BMG_PW3433,,,"Missense mutations in the kinase domain (KD) of TGF-beta receptor II (TGFBR2) are found in ~20% of microsatellite stable (MSS) colon cancers and make affected tumors resistant to TGF-beta (TGFB1)-mediated growth inhibition (Grady et al. 1999). While both alleles of TGFBR2 are affected by inactivating mutations in MSS colorectal cancer (Grady et al. 1999), a study of MSS esophageal carcinoma indicates that TGFBR2 KD mutations may function in a dominant-negative way (Tanaka et al. 2000). KD mutations in TGFBR2 are rarely reported in microsatellite instable (MSI) colorectal cancer (Parsons et al. 1995, Takenoshita et al. 1997)."
BMGC_PW1004,BMG_PW3434,,,"Carbohydrate sulfotransferase 6 (CHST6) catalyzes the transfer of sulfate to position 6 of non-reducing ends of N-acetylglucosamine (GlcNAc) residues on keratan sulfate (KS). KS plays a central role in maintaining corneal transparency. Defective CHST6 (Nakazawa et al. 1984) results in unsulfated keratan deposited within the intracellular space and the extracellular corneal stroma leading to macular dystrophy, corneal type I (MCDC1; MIM:217800). MCDC1 is an early-onset, ocular disease characterized by bilateral, progressive corneal opacification, and reduced corneal sensitivity (Jones & Zimmerman 1961). MCD can be subdivided into 2 types on the basis of immunohistochemical studies and serum analysis for keratan sulfate; MCD type I, in which there is a virtual absence of sulfated KS-specific antibody response in the serum and cornea and MCD type II, in which the normal KS-specific antibody response is present in cornea and serum (Yang et al. 1988)."
BMGC_PW1005,BMG_PW3436,,,"Heparan sulfate (HS) is involved in regulating various body functions during development, homeostasis and pathology including blood clotting, angiogenesis and metastasis of cancer cells. Exostosin 1 and 2 (EXT1 and 2) glycosyltransferases are required to form HS. They are able to transfer N-acetylglucosamine (GlcNAc) and glucuronate (GlcA) to HS during its synthesis. The functional form of these enzymes appears to be a complex of the two located on the Golgi membrane. Defects in either EXT1 or EXT2 can cause hereditary multiple exostoses 1 (Petersen 1989) and 2 (McGaughran et al. 1995) respectively (MIM:133700 and MIM:133701), autosomal dominant disorders characterised by multiple projections of bone capped by cartilage resulting in deformed legs, forearms and hands."
BMGC_PW1006,BMG_PW3437,,,"CMP-N-acetylneuraminate-beta-1,4-galactoside alpha-2,3-sialyltransferase (ST3GAL3) mediates the transfer of sialic acid from CMP-sialic acid to galactose-containing glycoproteins and forms the sialyl Lewis a epitope on proteins which are required for attaining and/or maintaining higher cognitive functions. Some defects in ST3GAL3 result in mental retardation, autosomal recessive 12 (MRT12; MIM:611090), a disorder characterised by below average general intellectual function and impaired adaptive behaviour (Najmabadi et al. 2007, Hu et al. 2011). Another defect of ST3GAL3 can cause early infantile epileptic encephalopathy-15 (EIEE15: MIM:615006), resulting in severe mental retardation (Edvardson et al. 2012)."
BMGC_PW1007,BMG_PW3438,,,"Congenital disorders of glycosylation (CDG, previously called carbohydrate-deficient glycoprotein syndromes, CDGSs), are a group of hereditary multisystem disorders. They are characterized biochemically by hypoglycosylation of glycoproteins, diagnosed by isoelectric focusing (IEF) of serum transferrin. There are two types of CDG, types I and II. Type I CDG has defects in the assembly of lipid-linked oligosaccharides or their transfer onto nascent glycoproteins, whereas type II CDG comprises defects of trimming, elongation, and processing of protein-bound glycans. Clinical symptoms are dominated by severe psychomotor and mental retardation, as well as blood coagulation abnormalities (Jaeken 2013). B4GALT1-CDG (CDG type IId) is a multisystem disease, characterized by dysmorphic features, hydrocephalus, hypotonia and blood clotting abnormalities (Hansske et al. 2002)."
BMGC_PW1008,BMG_PW3440,,,"Heparan sulfate (HS) is involved in regulating various body functions functions during development, homeostasis and pathology including blood clotting, angiogenesis and metastasis of cancer cells. Exostosin 1 and 2 (EXT1 and 2) glycosyltransferases are required to form HS. They are able to transfer N-acetylglucosamine (GlcNAc) and glucuronate (GlcA) to HS during its synthesis. The functional form of these enzymes appears to be a complex of the two located on the Golgi membrane. Defects in either EXT1 or EXT2 can cause hereditary multiple exostoses 1 (Petersen 1989) and 2 (McGaughran et al. 1995) respectively (MIM:133700 and MIM:133701), autosomal dominant disorders characterized by multiple projections of bone capped by cartilage resulting in deformed legs, forearms and hands. Trichorhinophalangeal syndrome, type II (TRPS2 aka Langer-Giedion syndrome, LGS) is a disorder that combines the clinical features of trichorhinophalangeal syndrome type I (TRPS1, MIM:190350) and multiple exostoses type I, caused by mutations in the TRPS1 and EXT1 genes, respectively (Langer et al. 1984, Ludecke et al. 1995). Defects in EXT1 may also be responsible for chondrosarcoma (CHDS; MIM:215300) (Schajowicz & Bessone 1967, Hecht et al. 1995)."
BMGC_PW1009,BMG_PW3441,,,"Mutations in the kinase domain (KD) of TGF-beta receptor 1 (TGFBR1) have been found in Ferguson-Smith tumor i.e. multiple self-healing squamous epithelioma - MSSE (Goudie et al. 2011), breast cancer (Chen et al. 1998), ovarian cancer (Chen et al. 2001) and head-and-neck cancer (Chen et al. 2001). KD mutations reported in MSSE are nonsense and frameshift mutations that cause premature termination of TGFBR1 translation, resulting in truncated receptors that lack substantial portions of the kinase domain, or cause nonsense-mediated decay of mutant transcripts. A splice site KD mutation c.806-2A>C is predicted to result in the skipping of exon 5 and the absence of KD amino acid residues 269-324 from the mutant receptor. The splice site mutant is expressed at the cell surface but unresponsive to TGF-beta stimulation (Goudie et al. 2004). TGFBR1 KD mutations reported in breast, ovarian and head-and-neck cancer are missense mutations, and it appears that these mutant proteins are partially functional but that their catalytic activity or protein stability is decreased (Chen et al. 1998, Chen et al. 2001a and b). These mutants are not shown."
BMGC_PW1010,BMG_PW3442,,,"TGF-beta receptor 1 (TGFBR1) loss-of-function is a less frequent mechanism for inactivation of TGF-beta signaling in cancer compared to SMAD4 and TGFBR2 inactivation. Genomic deletion of TGFBR1 locus has been reported in pancreatic cancer (Goggins et al. 1998), biliary duct cancer (Goggins et al. 1998) and lymphoma (Schiemann et al. 1999), while loss-of-function mutations have been reported in breast (Chen et al. 1998) and ovarian cancer (Chen et al. 2001), metastatic head-and-neck cancer (Chen et al. 2001), and in Ferguson-Smith tumors (multiple self-healing squamous epithelioma - MSSE) (Goudie et al. 2011). Loss-of-function mutations mainly affect the ligand-binding extracellular domain of TGFBR1 and the kinase domain of TGFBR1 (Goudie et al. 2011). In the mouse model of colorectal cancer, Tgfbr1 haploinsufficiency cooperates with Apc haploinsufficiency in the development of intestinal tumors (Zeng et al. 2009)."
BMGC_PW1011,BMG_PW3443,,,"Mutations in the ligand-binding domain (LBD) of TGF-beta receptor 1 (TGFBR1) have been reported as germline mutations in Ferguson-Smith tumor (multiple self-healing squamous epithelioma - MSSE), an autosomal-dominant skin cancer condition (Ferguson-Smith et al. 1934, Ferguson-Smith et al. 1971), with tumors frequently showing loss of heterozygosity of the wild-type TGFBR1 allele (Goudie et al. 2011). Somatic mutations in the LBD of TGFBR1 have been reported in esophageal carcinoma (Dulak et al. 2013)."
BMGC_PW1012,BMG_PW3444,,,"The tumor suppressor TP53 (encoded by the gene p53) is a transcription factor. Under stress conditions, it recognizes specific responsive DNA elements and thus regulates the transcription of many genes involved in a variety of cellular processes, such as cellular metabolism, survival, senescence, apoptosis and DNA damage response. Because of its critical function, p53 is frequently mutated in around 50% of all malignant tumors. For a recent review, please refer to Vousden and Prives 2009 and Kruiswijk et al. 2015."
BMGC_PW1013,BMG_PW3445,,,Integrin signaling is linked to the MAP kinase pathway by recruiting p130cas and Crk to the FAK/Src activation complex.
BMGC_PW1014,BMG_PW3446,,,"Rhodopsin-like receptors (class A/1) are the largest group of GPCRs and are the best studied group from a functional and structural point of view. They show great diversity at the sequence level and thus, can be subdivided into 19 subfamilies (Subfamily A1-19) based on a phylogenetic analysis (Joost P and Methner A, 2002). They represent members which include hormone, light and neurotransmitter receptors and encompass a wide range of functions including many autocrine, paracrine and endocrine processes."
BMGC_PW1015,BMG_PW3447,,,"This family is known as Family B (secretin-receptor family, family 2) G-protein-coupled receptors. Family B GPCRs include secretin, calcitonin, parathyroid hormone/parathyroid hormone-related peptides and vasoactive intestinal peptide receptors; all of which activate adenylyl cyclase and the phosphatidyl-inositol-calcium pathway (Harmar AJ, 2001)."
BMGC_PW1016,BMG_PW3448,,,"Netrins are secreted proteins that play a crucial role in neuronal migration and in axon guidance during the development of the nervous system. To date, several Netrins have been described in mouse and humans: Netrin-1, -3/NTL2, -4/h and G-Netrins. Netrin-1 is the most studied member of the family and has been shown to play a crucial role in neuronal navigation during nervous system development mainly through its interaction with its receptors DCC and UNC5. Members of the Deleted in colorectal cancer (DCC) family- which includes DCC and Neogenin in vertebrates- mediate netrin-induced axon attraction, whereas the C. elegans UNC5 receptor and its four vertebrate homologs Unc5a-Unc5d mediate repulsion."
BMGC_PW1017,BMG_PW3449,,,"Nephrin (NPHS1) is a member of the Super-IgG-Molecule family and is most prominently expressed in kidney podocytes. It is a major if not the most important structural component of the slit diaphragm, a modified adherens junction in between these cells. NPHS1 has an extracellular domain that contains eight distal IgG like domains and one proximal fibronectin type III domain, a transmembrane domain and a short intracellular domain. NPHS1 molecules show both homophilic and heterophilic interactions. Among heterophilic interaction partners, slit diaphragm proteins such as Kin of IRRE-like protein 1 (KIRREL, Nephrin-like protein 1, NEPH1), KIRREL3 (NEPH2) and KIRREL2 (NEPH3) were shown to stabilize the slit diaphragm structure. Intracellularly Podocin (NPHS2), CD2 associated protein (CD2AP) and adherins junction associated proteins like IQGAP, MAGI, CASK and spectrins all interact with NPHS1. Hence it seems to play a major role in organizing the molecular structure of the slit diaphragm itself and via its binding partners links it to the actin cytoskeleton. NPHS1 tyrosine phosphorylation by the Src kinase FYN initiates the PI3K-AKT signaling cascade, which seems to promote antiapoptotic signals."
BMGC_PW1018,BMG_PW3450,,,Semaphorins are a large family of cell surface and secreted guidance molecules divided into eight classes on the basis of their structures. They all have an N-terminal conserved sema domain. Semaphorins signal through multimeric receptor complexes that include other proteins such as plexins and neuropilins.
BMGC_PW1019,BMG_PW3452,,,"The L1 family of cell adhesion molecules (L1CAMs) are a subfamily of the immunoglobulin superfamily of transmembrane receptors, comprised of four structurally related proteins: L1, Close Homolog of L1 (CHL1), NrCAM, and Neurofascin. These CAMs contain six Ig like domains, five or six fibronectin like repeats, a transmembrane region and a cytoplasmic domain. The L1CAM family has been implicated in processes integral to nervous system development, including neurite outgrowth, neurite fasciculation and inter neuronal adhesion. L1CAM members are predominately expressed by neuronal, as well as some nonneuronal cells, during development. Except CHL1 all the other members of L1 family contain an alternatively spliced 12-nclueotide exon, encoding the amino acid residues RSLE in the neuronal splice forms but missing in the non-neuronal cells. The extracellular regions of L1CAM members are divergent and differ in their abilities to interact with extracellular, heterophilic ligands. The L1 ligands include other Ig-domain CAMs (such as NCAM, TAG-1/axonin and F11), proteoglycans type molecules (neurocan), beta1 integrins, and extra cellular matrix protein laminin, Neuropilin-1, FGF and EGF receptors. Some of these L1-interacting proteins also bind to other L1CAM members. For example TAG-1/axonin interact with L1 and NrCAM; L1, neurofascin and CHL1 binds to contactin family members. The cytoplasmic domains of L1CAM members are most highly conserved. Nevertheless, they have different cytoplasmic binding partners, and even those with similar binding partners may be involved in different signaling complexes and mechanisms. The most conserved feature of L1CAMs is their ability to interact with the actin cytoskeletal adapter protein ankyrin. The cytoplasmic ankyrin-binding domain, exhibits the highest degree of amino acid conservation throughout the L1 family."
BMGC_PW1020,BMG_PW3453,,,"The neural cell adhesion molecule, NCAM, is a member of the immunoglobulin (Ig) superfamily and is involved in a variety of cellular processes of importance for the formation and maintenance of the nervous system. The role of NCAM in neural differentiation and synaptic plasticity is presumed to depend on the modulation of intracellular signal transduction cascades. NCAM based signaling complexes can initiate downstream intracellular signals by at least two mechanisms: (1) activation of FGFR and (2) formation of intracellular signaling complexes by direct interaction with cytoplasmic interaction partners such as Fyn and FAK. Tyrosine kinases Fyn and FAK interact with NCAM and undergo phosphorylation and this transiently activates the MAPK, ERK 1 and 2, cAMP response element binding protein (CREB) and transcription factors ELK and NFkB. CREB activates transcription of genes which are important for axonal growth, survival, and synaptic plasticity in neurons. NCAM1 mediated intracellular signal transduction is represented in the figure below. The Ig domains in NCAM1 are represented in orange ovals and Fn domains in green squares. The tyrosine residues susceptible to phosphorylation are represented in red circles and their positions are numbered. Phosphorylation is represented by red arrows and dephosphorylation by yellow. Ig, Immunoglobulin domain; Fn, Fibronectin domain; Fyn, Proto-oncogene tyrosine-protein kinase Fyn; FAK, focal adhesion kinase; RPTPalpha, Receptor-type tyrosine-protein phosphatase; Grb2, Growth factor receptor-bound protein 2; SOS, Son of sevenless homolog; Raf, RAF proto-oncogene serine/threonine-protein kinase; MEK, MAPK and ERK kinase; ERK, Extracellular signal-regulated kinase; MSK1, Mitogen and stress activated protein kinase 1; CREB, Cyclic AMP-responsive element-binding protein; CRE, cAMP response elements."
BMGC_PW1021,BMG_PW3454,,,"These receptors, a subset of the Class A/1 (Rhodopsin-like) family, all bind peptide ligands which include the chemokines, opioids and somatostatins."
BMGC_PW1022,BMG_PW3455,,,"The class A (rhodopsin-like) GPCRs that bind to classical biogenic amine ligands are annotated here. The amines involved (acetylcholine, adrenaline, noradrenaline, dopamine, serotonin and histamine) can all act as neurotransmitters in humans. The so-called 'trace amines', used when referring to p-tyramine, beta-phenylethylamine, tryptamine and octopamine, can also bind to recently-discovered GPCRs."
BMGC_PW1023,BMG_PW3456,,,"The class A (rhodopsin-like) GPCRs that bind to hormone ligands are annotated here. The hormones follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH) and human chorionic gonadotrophin (hCG) are dimeric glycoproteins, sharing an identical alpha subunit and varying beta subunits. Their actions are mediated by the respective GPCRs, influencing reproductive processes and thyroid hormone release."
BMGC_PW1024,BMG_PW3457,,,"DSCAM (Down syndrome cell adhesion molecule) is one of the members of the Ig superfamily CAMs with a domain architecture comprising 10 Ig domains, 6 fibronectin type III (FN) repeats, a single transmembrane and a C terminal cytoplasmic domain. DSCAM is implicated in Down syndrome (DS) due to the chromosomal location of the DSCAM gene, but no evidence supports a direct involvement of DSCAM with DS. It likely functions as a cell surface receptor mediating axon pathfinding. Besides these important implications, little is known about the physiological function or the molecular mechanism of DSCAM signal transduction in mammalian systems. A closely related DSCAM paralogue Down syndrome cell adhesion moleculelike protein 1 (DSCAML1) is present in humans. Both these proteins are involved in homophilic intercellular interactions."
BMGC_PW1025,BMG_PW3458,,,"The Roundabout (ROBO) family encodes transmembrane receptors that regulate axonal guidance and cell migration. The major function of the Robo receptors is to mediate repulsion of the navigating growth cones. There are four human Robo homologues, ROBO1, ROBO2, ROBO3 and ROBO4. Most of the ROBOs have the similar ectodomain architecture as the cell adhesion molecules, with five Ig domains followed by three FN3 repeats, except for ROBO4. ROBO4 has two Ig and two FN3 repeats. The cytoplasmic domains of ROBO receptors are in general poorly conserved. However, there are four short conserved cytoplasmic sequence motifs, named CC0-3, that serve as binding sites for adaptor proteins. The ligands for the human ROBO1 and ROBO2 receptors are the three SLIT proteins SLIT1, SLIT2, and SLIT3; all of the SLIT proteins contain a tandem of four LRR (leucine rich repeat) domains at the N-terminus, termed D1-D4, followed by six EGF (epidermal growth factor)-like domains, a laminin G like domain (ALPS), three EGF-like domains, and a C-terminal cysteine knot domain. Most SLIT proteins are cleaved within the EGF-like region by unknown proteases (reviewed by Hohenster 2008, Ypsilanti and Chedotal 2014, Blockus and Chedotal 2016). NELL2 is a ligand for ROBO3 (Jaworski et al. 2015). SLIT protein binding modulates ROBO interactions with the cytosolic adaptors. The cytoplasmic domain of ROBO1 and ROBO2 determines the repulsive responses of these receptors. Based on the studies from both invertebrate and vertebrate organisms it has been inferred that ROBO induces growth cone repulsion by controlling cytoskeletal dynamics via either Abelson kinase (ABL) and Enabled (Ena), or RAC1 activity (reviewed by Hohenster 2008, Ypsilanti and Chedotal 2014, Blockus and Chedotal 2016). While there is some redundancy in the function of ROBO receptors, ROBO1 is implicated as the predominant receptor for axon guidance in ventral tracts, and ROBO2 is the predominant receptor for axon guidance in dorsal tracts. ROBO2 also repels neuron cell bodies from the floor plate (Kim et al. 2011). In addition to regulating axon guidance, ROBO1 and ROBO2 receptors are also implicated in regulation of proliferation and transition of primary to intermediate neuronal progenitors through a poorly characterized cross-talk with NOTCH-mediated activation of HES1 transcription (Borrell et al. 2012). Thalamocortical axon extension is regulated by neuronal activity-dependent transcriptional regulation of ROBO1 transcription. Lower neuronal activity correlates with increased ROBO1 transcription, possibly mediated by the NFKB complex (Mire et al. 2012). It is suggested that the homeodomain transcription factor NKX2.9 stimulates transcription of ROBO2, which is involved in regulation of motor axon exit from the vertebrate spinal code (Bravo-Ambrosio et al. 2012). Of the four ROBO proteins, ROBO4 is not involved in neuronal system development but is, instead, involved in angiogenesis. The interaction of ROBO4 with SLIT3 is involved in proliferation, motility and chemotaxis of endothelial cells, and accelerates formation of blood vessels (Zhang et al. 2009)."
BMGC_PW1026,BMG_PW3459,,,"The mechanisms involved in downregulation of TCF-dependent transcription are not yet very well understood. beta-catenin is known to recruit a number of transcriptional repressors, including Reptin, SMRT and NCoR, to the TCF/LEF complex, allowing the transition from activation to repression (Bauer et al, 2000; Weiske et al, 2007; Song and Gelmann, 2008). CTNNBIP1 (also known as ICAT) and Chibby are inhibitors of TCF-dependent signaling that function by binding directly to beta-catenin and preventing interactions with critical components of the transactivation machinery (Takemaru et al, 2003; Li et al, 2008; Tago et al, 2000; Graham et al, 2002; Daniels and Weiss, 2002). Chibby additionally promotes the nuclear export of beta-catenin in conjunction with 14-3-3/YWHAZ proteins (Takemura et al, 2003; Li et al, 2008). A couple of recent studies have also suggested a role for nuclear APC in the disassembly of the beta-catenin activation complex (Hamada and Bienz, 2004; Sierra et al, 2006). It is worth noting that while some of the players involved in the disassembly of the beta-catenin transactivating complex are beginning to be worked out in vitro, the significance of their role in vivo is not yet fully understood, and some can be knocked out with little effect on endogenous WNT signaling (see for instance Voronina et al, 2009)."
BMGC_PW1027,BMG_PW3460,,,"Several unrelated families of secreted proteins antagonize WNT signaling. Secreted frizzled-related proteins (sFRPs) have a cysteine rich domain (CRD) that is also found in FZD and ROR receptors, while WNT inhibitory factor (WIF) proteins contain a WIF domain also present in the WNT-receptor RYK. Both these classes of secreted WNT antagonists inhibit signaling by binding to WNTs and preventing their interaction with the FZD receptors. sFRPs may also able to bind the receptors, blocking ligand binding (Bafico et al, 1999; reviewed in Kawano and Kypta, 2003). The interaction of WIF and sFRPs with WNT ligand may also play a role in regulating WNT diffusion and gradient formation (reviewed in Boloventa et al, 2008). Dickkopf (DKK) and Sclerostin (SOST) family members, in contrast, antagonize WNT signaling by binding to LRP5/6. There are four DKK family members in vertebrates; the closely related DKK1, 2 and 4 proteins have been shown to have roles in WNT signaling, while the more divergent DKK3 appears not to (Glinka et al, 1998; Fedi et al, 1999; Mao et al, 2001; Semenov et al, 2001; reviewed in Niehrs, 2006). Secreted DKK proteins bind to LRP6 in conjunction with the single-pass transmembrane proteins Kremen 1 and 2, and this interaction is thought to disrupt the WNT-induced FZD-LRP5/6 complex. In some cases, DKK2 has also been shown to function as a WNT agonist (reviewed in N (reviewed in Niehrs, 2006). Like DKK proteins, SOST binds LRP5/6 and disrupts WNT-dependent receptor activation (Semenov et al, 2005)."
BMGC_PW1028,BMG_PW3462,,,"Diseases of glycosylation, usually referred to as congenital disorders of glycosylation (CDG), are rare inherited disorders ascribing defects of nucleotide-sugar biosynthesis and transport, glycosyl transfer events and vesicular transport. Most CDGs cause neurological impairment ranging from severe psychomotor retardation to mild intellectual disability. Defects in N-glycosylation are the main cause of CDGs (Marquardt & Denecke 2003, Grunewald et al. 2002, Hennet 2012, Goreta et al. 2012) and can be identified by a characteristic abnormal isoelectric focusing profile of plasma transferrin (Jaeken et al. 1984, Stibler & Jaeken 1990). Disorders of O-glycosylation, glycosaminoglycan and glycolipid metabolism have recently been discovered and, together with N-glycosylation, represent the major pathways affected by glycan biosynthetic disorders (Freeze 2006, Jaeken 2011). In addition, glycosylation diseases associated with the enzymes that mediate the biosynthesis of glycosylation precursors are described in this section. As the number of these disorders has increased, nomenclature has been simplified so that now, the name of the mutant gene is followed by the abbreviation CDG (Jaeken et al. 2009). Effective therapies for most types of CDGs are so far not available (Thiel & Korner 2013)."
BMGC_PW1029,BMG_PW3463,,,"Lafora disease is a progressive neurodegenerative disorder with onset typically late in childhood, characterized by seizures and progressive neurological deterioration and death within ten years of onset. Recessive mutations in EPM2A (laforin) and NHLRC1 (malin) have been identified as causes of the disease. The disease is classified here as one of glycogen storage as EPM2A (laforin) and NHLRC1 (malin) regulate normal glycogen turnover and defects in either protein are associated with the formation of Lafora bodies, accumulations of abnormal, insoluble glycogen molecules in tissues including brain, muscle, liver, and heart (Ramachandran et al. 2009; Roach et al. 2012). Consistent with a central role for glycogen accumulation in the disease, reduced (Turnbull et al. 2011) or absent (Pederson et al. 2013) glycogen synthase activity prevents Lafora Disease in mouse models. Type 2A disease. EPM2A (laforin) associated with cytosolic glycogen granules, normally catalyzes the removal of the phosphate groups added rarely but consistently to growing glycogen molecules (Tagliabracci et al. 2011). Defects in this catalytic activity lead to the formation of phosphorylated glycogen molecules that are insoluble and that show abnormal branching patterns (Minassian et al. 1998, Serratosa et al. 1999, Tagliabracci et al. 2011). Type 2B disease. NHLRC1 (malin) normally mediates polyubiquitination of EPM2A (laforin) and PPP1R3C (PTG). The two polyubiquitinated proteins are targeted for proteasome-mediated degradation, leaving a glycogen-glycogenin particle associated with glycogen synthase. In the absence of NHLRC1 activity, EPM2A and PPP1R3C proteins appear to persist, associated with the formation of abnormal, stable glycogen granules (Lafora bodies) (Chan et al. 2003; Gentry et al. 2005). In NHLRC1 knockout mice PPP1R3C levels are unchanged rather than increased, suggesting that NHLRC1 does not target PPP1R3C for degradation. However, EPM2A protein levels are increased in this knockout consistent with NHLRC1's proposed role (DePaoli-Roach et al. 2010)."
BMGC_PW1030,BMG_PW3464,,,Dopamine once taken up by the dopamine transporter from the extracellular space into the cytosol is metabolized in a two step reaction to homovanillic acid.The first reaction is catalyzed by catecholamine o-methyl transferase and the subsequent reaction is catalyzed by monoamine oxidase A.
BMGC_PW1031,BMG_PW3465,,,"Alternately dopamine is metabolized to homovanillic acid in a two-step reaction in which dopamine is first oxidized to 3,4-dihydroxypheylacetic acid (DOPAC) and then converted to homovanillic acid by catecholamine o-methyltransferase."
BMGC_PW1032,BMG_PW3466,,,"The human gene SLC6A3 encodes the sodium-dependent dopamine transporter, DAT which mediates the re-uptake of dopamine from the synaptic cleft (Vandenbergh DJ et al, 2000). Dopamine can then be degraded by either COMT or monoamine oxidase."
BMGC_PW1033,BMG_PW3467,,,"Cytosolic tRNA synthetases catalyze the reactions of tRNAs encoded in the nuclear genome, their cognate amino acids, and ATP to form aminoacyl-tRNAs, AMP, and pyrophosphate. Eight of the tRNA synthetases, those specific for arginine, aspartate, glutamate and proline, glutamine, isoleucine, leucine, lysine, and methionine, associate to form a complex with three accessory proteins. Each of the component synthetases is active in vitro as a purified protein; complex formation is thought to channel aminoacylated tRNAs more efficiently to the site of protein synthesis in mRNA:ribosome complexes (Quevillon et al. 1999; Wolfe et al. 2003, 2005)."
BMGC_PW1034,BMG_PW3468,,,"tRNA synthetases catalyze the ligation of tRNAs to their cognate amino acids in an ATP-dependent manner. The reaction proceeds in two steps. First, amino acid and ATP form an aminoacyl adenylate molecule, releasing pyrophosphate. The aminoacyl adenylate remains associated with the synthetase enzyme where, in the second step it reacts with tRNA to form aminoacyl tRNA and AMP. The rapid hydrolysis of pyrophosphate makes these reactions essentially irreversible under physiological conditions (Fersht and Kaethner 1976a). Specificity of the tRNA charging reactions is achieved both by specific recognition of amino acid and tRNA substrates by the synthetase, and by an editing process in which incorrect aminoacyl adenylate molecules (e.g., valyl adenylate associated with isoleucyl tRNA synthetase) are hydrolyzed rather than conjugated to tRNAs in the second step of the reaction (Baldwin and Berg 1966a,b; Fersht and Kaethner 1976b). The tRNA synthetases can be divided into two structural classes based on conserved amino acid sequence features (Burnbaum and Schimmel 1991). A single synthetase mediates the charging of all of the tRNA species specific for any one amino acid but, with three exceptions, glycine, lysine, and glutamine, the synthetase that catalyzes aminoacylation of mitochondrial tRNAs is encoded by a different gene than the one that acts on mitochondrial tRNAs. Both mitochondrial and cytosolic tRNA synthetase enzymes are encoded by genes in the nuclear genome. A number of tRNA synthetases are known to have functions distinct from tRNA charging (reviewed by Park et al. 2005). Additionally, mutations in several of the tRNA synthetases, often affecting protein domains that are dispensable in vitro for aminoacyl tRNA synthesis, are associated with a diverse array of neurological and other diseases (Antonellis and Green 2008; Park et al. 2008). These findings raise interest into the role of these enzymes in human development and disease."
BMGC_PW1035,BMG_PW3470,,,"During interphase, Nlp interacts with gamma-tubulin ring complexes (gamma-TuRC), and is thought to contribute to the organization of interphase microtubules (Casenghi et al.,2003). Plk1 is activated at the onset of mitosis and phosphorylates Nlp triggering its displacement from the centrosome (Casenghi et al.,2003). Removal of Nlp appears to contribute to the establishment of a mitotic scaffold with enhanced microtubule nucleation activity."
BMGC_PW1036,BMG_PW3471,,,"The mitotic spindle becomes established once centrosomes have migrated to opposite poles and the nuclear envelope has broken down. During this stage, interphase centrosomes mature into mitotic centrosomes recruiting additional gamma TuRC complexes and acquiring mitosis-associated centrosomal proteins including NuMA, Plk1 and CDK11p58 (reviewed in Schatten 2008; Raynaud-Messina and Merdes 2007)."
BMGC_PW1037,BMG_PW3472,,,"In addition to recruiting proteins and complexes necessary for increased microtubule nucleation, centrosomal maturation involves the loss of proteins involved in interphase microtubule organization and centrosome cohesion (Casenghi et al., 2003; Mayor et al., 2002)."
BMGC_PW1038,BMG_PW3473,,,"The centrosome is the primary microtubule organizing center (MTOC) in vertebrate cells and plays an important role in orchestrating the formation of the mitotic spindle. Centrosome maturation is an early event in this process and involves a major reorganization of centrosomal material at the G2/M transition. During maturation, centrosomes undergo a dramatic increase in size and microtubule nucleating capacity. As part of this process, a number of proteins and complexes, including some that are required for microtubule nucleation and anchoring, are recruited to the centrosome while others that are required for organization of interphase microtubules and centrosome cohesion are lost (reviewed in Schatten, 2008; Raynaud-Messina and Merdes 2007)."
BMGC_PW1039,BMG_PW3474,,,"The NuMA protein, which functions as a nuclear matrix protein in interphase (Merdes and Cleveland 1998), redistributes to the cytoplasm following nuclear envelope breakdown where it plays an essential role in formation and maintenance of the spindle poles (Gaglio, et al., 1995; Gaglio, et al., 1996; Merdes et al, 1996). The mitotic activation of NuMA involves Ran-GTP-dependent dissociation from importin (Nachury et al, 2001, Wiese et al, 2001). NuMA is transported to the mitotic poles where it forms an insoluble crescent around centrosomes tethering microtubules into the bipolar configuration of the mitotic apparatus (Merdes et al., 2000; Kisurina-Evgenieva et al, 2004). Although NuMA is not a bona fide constituent of the mitotic centrosome but rather a protein associated with microtubules at the spindle pole, specific splice variants of NuMA have been identified that associate with the centrosome during interphase (Tang et al, 1994)."
BMGC_PW1040,BMG_PW3475,,,"Serotonergic neurotransmission affects a wide range of behaviors, from food intake and reproductive activity, to sensory processing and motor activity, to cognition and emotion. One such key regulator is the serotonin transporter (5-HTT), which is observed to remove serotonin released into the synaptic cleft."
BMGC_PW1041,BMG_PW3476,,,"Upon formation of a trimeric LKB1:STRAD:MO25 complex, LKB1 phosphorylates and activates AMPK. This phosphorylation is immediately removed in basal conditions by PP2C, but if the cellular AMP:ATP ratio rises, this activation is maintained, as AMP binding by AMPK inhibits the dephosphorylation. AMPK then activates the TSC complex by phosphorylating TSC2. Active TSC activates the intrinsic GTPase activity of Rheb, resulting in GDP-loaded Rheb and inhibition of mTOR pathway."
BMGC_PW1042,BMG_PW3477,,,"ATF4 is a transcription factor and activates expression of IL-8, MCP1, IGFBP-1, CHOP, HERP1 and ATF3."
BMGC_PW1043,BMG_PW3478,,,"ATF6-alpha is a transmembrane protein that normally resides in the Endoplasmic Reticulum (ER) membrane. Here its luminal C-terminal domain is associated with BiP, shielding 2 Golgi-targeting regions and thus keeping ATF6-alpha in the ER. Upon interaction of BiP with unfolded proteins in the ER, ATF6-alpha dissociates and transits to the Golgi where it is cleaved by the S1P and S2P proteases that reside in the Golgi, releasing the N-terminal domain of ATF6-alpha into the cytosol. After transiting to the nucleus, the N-terminal domain acts as a transcription factor to activate genes encoding chaperones."
BMGC_PW1044,BMG_PW3479,,,"Xbp-1 (S) binds the sequence CCACG in ER Stress Responsive Elements (ERSE, consensus sequence CCAAT (N)9 CCACG) located upstream from many genes. The ubiquitous transcription factor NF-Y, a heterotrimer, binds the CCAAT portion of the ERSE and together the IRE1-alpha: NF-Y complex activates transcription of a set of chaperone genes including DNAJB9, EDEM, RAMP4, p58IPK, and others. This results in an increase in protein folding activity in the ER."
BMGC_PW1045,BMG_PW3480,,,"PERK (EIF2AK3) is a single-pass transmembrane protein located in the endoplasmic reticulum (ER) membrane such that the N-terminus of PERK is luminal and the C-terminus is cytosolic. PERK is maintained in an inactive form by interaction of its luminal domain with BiP, an ER chaperone. BiP also binds unfolded proteins and so BiP dissociates from PERK when unfolded proteins accumulate in the ER. Dissociated PERK monomers spontaneously form homodimers and the homodimeric form of PERK possesses kinase activity in its cytosolic C-terminal domain. The kinase specifically phosphorylates the translation factor eIF2alpha at Ser52, resulting in an arrest of translation. Thus translation of proteins targeted to the ER is downregulated. The translation arrest also causes depletion of Cyclin D1, a rapidly turned over protein. The depletion of Cyclin D1 in turn causes arrest of the cell cycle in G1 phase."
BMGC_PW1046,BMG_PW3481,,,"IRE1-alpha is a single-pass transmembrane protein that resides in the endoplasmic reticulum (ER) membrane. The C-terminus of IRE1-alpha is located in the cytosol; the N-terminus is located in the ER lumen. In unstressed cells IRE1-alpha exists in an inactive heterodimeric complex with BiP such that BiP in the ER lumen binds the N-terminal region of IRE1-alpha. Upon accumulation of unfolded proteins in the ER, BiP binds the unfolded protein and the IRE1-alpha:BiP complex dissociates. The dissociated IRE1-alpha then forms homodimers. Initially the luminal N-terminal regions pair. This is followed by trans-autophosphorylation of IRE1-alpha at Ser724 in the cytosolic C-terminal region. The phosphorylation causes a conformational change that allows the dimer to bind ADP, causing a further conformational change to yield back-to-back pairing of the cytosolic C-terminal regions of IRE1-alpha. The fully paired IRE1-alpha homodimer has endoribonuclease activity and cleaves the mRNA encoding Xbp-1. A 26 residue polyribonucleotide is released and the 5' and 3' fragments of the original Xbp-1 mRNA are rejoined. The spliced Xbp-1 message encodes Xbp-1 (S), a potent activator of transcription. Xbp-1 (S) together with the ubiquitous transcription factor NF-Y bind the ER Stress Responsive Element (ERSE) in a number of genes encoding chaperones. Recent data suggest that the IRE1-alpha homodimer can also cleave specific subsets of mRNAs, including the insulin (INS) mRNA in pancreatic beta cells."
BMGC_PW1047,BMG_PW3482,,,"The N-terminal fragment of ATF6-alpha contains a bZIP domain and binds the sequence CCACG in ER Stress Response Elements (ERSEs). ATF6-alpha binds ERSEs together with the heterotrimeric transcription factor NF-Y, which binds the sequence CCAAT in the ERSEs, and together the two factors activate transcription of ER stress-responsive genes. Evidence from overexpression and knockdowns indicates that ATF6-alpha is a potent activator but its homolog ATF6-beta is not and ATF6-beta may actually reduce expression of ER stress proteins."
BMGC_PW1048,BMG_PW3483,,,"Adipogenesis is the process of cell differentiation by which preadipocytes become adipocytes. During this process the preadipocytes cease to proliferate, begin to accumulate lipid droplets and develop morphologic and biochemical characteristics of mature adipocytes such as hormone responsive lipogenenic and lipolytic programs. The most intensively studied model system for adipogenesis is differentiation of the mouse 3T3-L1 preadipocyte cell line by an induction cocktail of containing mitogens (insulin/IGF1), glucocorticoid (dexamethasone), an inducer of cAMP (IBMX), and fetal serum (Cao et al. 1991, reviewed in Farmer 2006). More recently additional cellular models have become available to study adipogenesis that involve almost all stages of development (reviewed in Rosen and MacDougald 2006). In vivo knockout mice lacking putative adipogenic factors have also been extensively studied. Human pathways are traditionally inferred from those discovered in mouse but are now beginning to be validated in cellular models derived from human adipose progenitors (Fischer-Posovszky et al. 2008, Wdziekonski et al. 2011). Adipogenesis is controlled by a cascade of transcription factors (Yeh et al. 1995, reviewed in Farmer 2006, Gesta et al. 2007). One of the first observable events during adipocyte differentiation is a transient increase in expression of the CEBPB (CCAAT/Enhancer Binding Protein Beta, C/EBPB) and CEBPD (C/EBPD) transcription factors (Cao et al. 1991, reviewed in Lane et al. 1999). This occurs prior to the accumulation of lipid droplets. However, it is the subsequent inductions of CEBPA and PPARG that are critical for morphological, biochemical and functional adipocytes. Ectopic expression of CEBPB alone is capable of inducing substantial adipocyte differentiation in fibroblasts while CEBPD has a minimal effect. CEBPB is upregulated in response to intracellular cAMP (possibly via pCREB) and serum mitogens (possibly via Krox20). CEBPD is upregulated in response to glucocorticoids. The exact mechanisms that upregulate the CEBPs are not fully known. CEBPB and CEBPD act directly on the Peroxisome Proliferator-activated Receptor Gamma (PPARG) gene by binding its promoter and activating transcription. CEBPB and CEBPD also directly activate the EBF1 gene (and possibly other EBFs) and KLF5 (Jimenez et al. 2007, Oishi 2005). The EBF1 and KLF5 proteins, in turn bind, and activate the PPARG promoter. Other hormones, such as insulin, affect PPARG expression and other transcription factors, such as ADD1/SREBP1c, bind the PPARG promoter. This is an area of ongoing research. During adipogenesis the PPARG gene is transcribed to yield 2 variants. The adipogenic variant 2 mRNA encodes 30 additional amino acids at the N-terminus compared to the widely expressed variant 1 mRNA. PPARG encodes a type II nuclear hormone receptor (remains in the nucleus in the absence of ligand) that forms a heterodimer with the Retinoid X Receptor Alpha (RXRA). The heterodimer was initially identified as a complex regulating the aP2/FABP4 gene and named ARF6 (Tontonoz et al. 1994). The PPARG:RXRA heterodimer binds a recognition sequence that consists of two hexanucleotide motifs (DR1 motifs) separated by 1 nucleotide. Binding occurs even in the absence of ligands, such as fatty acids, that activate PPARG. In the absence of activating ligands, the PPARG:RXRA complex recruits repressors of transcription such as SMRT/NCoR2, NCoR1, and HDAC3 (Tontonoz and Spiegelman 2008). Each molecule of PPARG can bind 2 molecules of activating ligands. Although, the identity of the endogenous ligands of PPARG is unknown, exogenous activators include fatty acids and the thiazolidinedione class of antidiabetic drugs (reviewed in Berger et al. 2005, Heikkinen et al. 2007, Lemberger et al. 1996). The most potent activators of PPARG in vitro are oxidized derivatives of unsaturated fatty acids.. Upon binding activating ligands PPARG causes a rearrangement of adjacent factors: Corepressors such as SMRT/NCoR2 are lost and coactivators such as TIF2, PRIP, CBP, and p300 are recruited (Tontonoz and Spiegelman). PPARG also binds directly to the TRAP220 subunit of the TRAP/Mediator complex that recruits RNA polymerase II. Thus binding of activating ligand by PPARG causes transcription of PPARG target genes. Targets of PPARG include genes involved in differentiation (PGAR/HFARP, Perilipin, aP2/FABP4, CEBPA), fatty acid transport (LPL, FAT/CD36), carbohydrate metabolism (PEPCK-C, AQP7, GK, GLUT4 (SLC2A4)), and energy homeostasis (LEPTIN and ADIPONECTIN) (Perera et al. 2006). Within 10 days of differentiation CEBPB and CEBPD are no longer located at the PPARG promoter. Instead CEBPA is present. EBF1 and PPARG bind the CEBPA promoter and activate transcription of CEBPA, one of the key transcription factors in adipogenesis. A current hypothesis posits a self-reinforcing loop that maintains PPARG expression and the differentiated state: PPARG activates CEBPA and CEBPA activates PPARG. Additionally EBF1 (and possibly other EBFs) activates CEBPA, CEBPA activates EBF1, and EBF1 activates PPARG."
BMGC_PW1049,BMG_PW3484,,,"The family of Insulin like Growth Factor Binding Proteins (IGFBPs) share 50% amino acid identity with conserved N terminal and C terminal regions responsible for binding Insulin like Growth Factors I and II (IGF I and IGF II). Most circulating IGFs are in complexes with IGFBPs, which are believed to increase the residence of IGFs in the body, modulate availability of IGFs to target receptors for IGFs, reduce insulin like effects of IGFs, and act as signaling molecules independently of IGFs. About 75% of circulating IGFs are in 1500 220 KDa complexes with IGFBP3 and ALS. Such complexes are too large to pass the endothelial barrier. The remaining 20 25% of IGFs are bound to other IGFBPs in 40 50 KDa complexes. IGFs are released from IGF:IGFBP complexes by proteolysis of the IGFBP. IGFs become active after release, however IGFs may also have activity when still bound to some IGFBPs. IGFBP1 is enriched in amniotic fluid and is produced in the liver under control of insulin (insulin suppresses production). IGFBP1 binding stimulates IGF function. It is unknown which if any protease degrades IGFBP1. IGFBP2 is enriched in cerebrospinal fluid; its binding inhibits IGF function. IGFBP2 is not significantly degraded in circulation. IGFB3, which binds most IGF in the body is enriched in follicular fluid and found in many other tissues. IGFBP 3 may be cleaved by plasmin, thrombin, Prostate specific Antigen (PSA, KLK3), Matrix Metalloprotease-1 (MMP1), and Matrix Metalloprotease-2 (MMP2). IGFBP3 also binds extracellular matrix and binding lowers its affinity for IGFs. IGFBP3 binding stimulates the effects of IGFs. IGFBP4 acts to inhibit IGF function and is cleaved by Pregnancy associated Plasma Protein A (PAPPA) to release IGF. IGFBP5 is enriched in bone matrix; its binding stimulates IGF function. IGFBP5 is cleaved by Pregnancy Associated Plasma Protein A2 (PAPPA2), ADAM9, complement C1s from smooth muscle, and thrombin. Only the cleavage site for PAPPA2 is known. IGFBP6 is enriched in cerebrospinal fluid. It is unknown which if any protease degrades IGFBP6."
BMGC_PW1050,BMG_PW3485,,,"Glucagon-like Peptide-1 (GLP-1) is secreted by L-cells in the intestine in response to glucose and fatty acids. GLP-1 circulates to the beta cells of the pancreas where it binds a G-protein coupled receptor, GLP-1R, on the plasma membrane. The binding activates the heterotrimeric G-protein G(s), causing the alpha subunit of G(s) to exchange GDP for GTP and dissociate from the beta and gamma subunits. The activated G(s) alpha subunit interacts with Adenylyl Cyclase VIII (Adenylate Cyclase VIII, AC VIII) and activates AC VIII to produce cyclic AMP (cAMP). cAMP then has two effects: 1) cAMP activates Protein Kinase A (PKA), and 2) cAMP activates Epac1 and Epac2, two guanyl nucleotide exchange factors. Binding of cAMP to PKA causes the catalytic subunits of PKA to dissociate from the regulatory subunits and become an active kinase. PKA is known to enhance insulin secretion by closing ATP-sensitive potassium channels, closing voltage-gated potassium channels, releasing calcium from the endoplasmic reticulum, and affecting insulin secretory granules. The exact mechanisms for PKA's action are not fully known. After prolonged increases in cAMP, PKA translocates to the nucleus where it regulates the PDX-1 and CREB transcription factors, activating transcription of the insulin gene. cAMP produced by AC VIII also activates Epac1 and Epac2, which catalyze the exchange of GTP for GDP on G-proteins, notably Rap1A. Rap1A regulates insulin secretory granules and is believed to activate the Raf/MEK/ERK mitogenic pathway leading to proliferation of beta cells. The Epac proteins also interact with RYR calcium channels on the endoplasmic reticulum, the SUR1 subunits of ATP-sensitive potassium channels, and the Piccolo:Rim2 calcium sensor at the plasma membrane."
BMGC_PW1051,BMG_PW3486,,"Within the compact cilia of the olfactory receptor neurons (ORNs) a cascade of enzymatic activity transduces the binding of an odorant molecule to a receptor into an electrical signal that can be transmitted to the brain. Odorant molecules bind to a receptor protein (R) coupled to an olfactory specific Gs-protein (G) and activate a type III adenylyl cyclase (AC), increasing intracellular cAMP levels. cAMP targets an olfactory-specific cyclic-nucleotide gated ion channel (CNG), allowing cations, particularly Na and Ca, to flow down their electrochemical gradients into the cell, depolarizing the ORN. Furthermore, the Ca entering the cell is able to activate a Ca-activated Cl channel, which would allow Cl to flow out of the cell, thus further increasing the depolarization. Elevated intracellular Ca causes adaptation by at least two different molecular steps: inhibition of the activity of adenylyl cyclase via CAMKII-dependent phosphorylation and down-regulation of the affinity of the CNG channel to cAMP.","Mammalian Olfactory Receptor (OR, also called odorant receptor) genes were discovered in rats by Linda Buck and Richard Axel, who predicted that odorants would be detected by a large family of G protein-coupled receptors (GPCRs) that are selectively expressed in the olfactory epithelium. This prediction was based on previous biochemical evidence that cAMP levels increased in olfactory neurons upon odor stimulation. These predictions proved to be accurate, and Buck and Axel received a Nobel Prize for this and subsequent work (reviewed in Keller & Vosshall 2008). Subsequent work in mice and other vertebrates has confirmed that OR genes are comprised of a very large family of G Protein-Coupled Receptors (GPCRs) that are selectively-expressed in olfactory epithelium. Although some OR are also expressed selectively in one or a few other tissues, their expression in olfactory-epithelium generally indicates a functional role in mediating olfaction, where they couple binding by odorant ligands with intracellular olfactory signaling. (Note: the other subclasses of GPCR signaling pathways are described under ""GPCR Signaling"".) The ligands for ORs are diverse, ranging from chemical compounds to peptides. Intracellular signaling by OR proteins in mice and other mammalian systems is known to be mediated via direct interactions of OR proteins with an olfactory-specific heterotrimeric G Protein, that contains an olfactory-specific G alpha protein: G alpha S OLPH (also named ""GNAL""). In model genetic systems such as mice, many candidate OR genes have been shown experimentally to function in olfactory signaling (reviewed in (Keller & Vosshall 2008). For the human OR genes, experimental analysis has been more limited, although some specific OR genes, such as OR7D4 and OR11H7P have been confirmed to mediate olfactory response and signaling in humans for specific chemical odorants (Keller et al. 2007, Abbafy 2007). Mice and other rodents are believed to have about 1000 functional OR genes, as well as many additional pseudogenes. Based on sequence similarities, there are 960 human OR genes, but approximately half of these are pseudogenes (Keller 2008). In mice, essentially all olfactory signaling requires G-alpha-S (OLF); mouse G-OLF knockouts have been shown to lack olfactory responses (Belluscio 1998). Bona fide human OR genes identified by sequence similarity (not pseudogenes with function-blocking mutations) that are expressed in olfactory epithelium are expected to interact with G alpha S OLF containing G Protein trimers. Of the 960 human OR genes and pseudogenes, there is experimental evidence that indicates over 430 are expressed in human olfactory epithelium, including 80 expressed OR pseudogenes (Zhang 2007). When expressed in model cell systems mammalian olfactory receptors (ORs) are typically retained in the ER and degraded by the proteasome (McClintock et al. 1997). A study using Caenorhabditis elegans showed that the transport of ORs to the cilia of olfactory neurons required the expression and association of ORs with a transmembrane protein, ODR4 (Dwyer et al. 1998). Co-transfection of rat ORs with ODR4 enhanced the transport and expression of ORs at the cell-surface (Gimelbrant et al. 2001). These studies suggested that olfactory neurons might have a selective molecular machinery that promotes expression of ORs at the cells surface. Two human protein families have been identified as potential accessory proteins involved in the trafficking of ORs to the plasma membrane (Saito et al. 2004). Receptor transporting proteins 1 and 2 (RTP1, RTP2) both strongly induced expression of several ORs at the cell-surface. To a lesser extent, the receptor expression enhancing protein 1 (REEP1) also promoted cell-surface expression. These proteins are specifically expressed in olfactory neurons with no expression in testis, where a subset of ORs are expressed (Parmentier et al. 1992, Spehr et al. 2003). Other members of the RTP and REEP families have a widespread distribution. RTP3 and RTP4 have been shown to promote cell-surface expression of the bitter taste receptors, TAS2Rs (Behrens et al. 2006). REEP1 and REEP5 (also known as DP1) are involved in shaping the ER by linking microtubule fibers to the ER (Park et al. 2010, Voeltz et al. 2006). A recent study looking at the role of REEP in the trafficking of Alpha2A- and Alpha2C-adrenergic receptors showed that REEP1-2 and 6 enhance the cell-surface expression of Alpha2C, but not Alpha2A, by increasing the capacity of ER cargo, thereby allowing more receptors to reach the cell-surface (Bjork et al. 2013). Unlike RTP1, REEP1-2 and 6 are only present in the ER, do not traffic to the plasma membrane and specifically interact with the minimal/non-glycosylated forms of Alpha2C via an interaction with its C-terminus (Saito et al. 2004, Bjork et al. 2013). REEPs may function as general modulators of the ER, rather than specifically interacting with GPCRs. Loss of association of REEP2 with membranes leads to hereditary spastic paraplegia (Esteves et al. 2014). Olfactory receptors (ORs, also called odorant receptors) are present on the plasma membrane of cilia of olfactory sensory neurons located in the olfactory epithelium of the nasal sinus. Each mature neuron expresses only one OR gene (reviewed in Nagai et al. 2016) and each OR binds one particular volatile chemical or set of volatile chemicals, known as odorants. The binding of an odorant to an OR (Mainland et al. 2015) causes a conformational change in the receptor that activates the G alpha subunit (Golf, GNAL) of an associated heterotrimeric G protein complex to exchange GDP for GTP (inferred from mouse homologs in Jones et al. 1990). GNAL:GTP and the Gbeta:Ggamma subcomplex (GNB1:GNG13) dissociate from the olfactory receptor and GNAL:GTP then binds and activates adenylate cyclase 3 (ADCY3) (inferred from rat homologs in Bakalyar and Reed 1990, reviewed in Boccaccio et al. 2021). Cyclic AMP produced by ADCY3 binds and opens the olfactory cyclic nucleotide-gated channel (CNG channel) composed of CNGA2, CNGA4, and CNGB isoform 1b (inferred from rat homologs in Liman and Buck 1994). The CNG channel translocates sodium and calcium cations from the extracellular region into the cytosol. The resulting cytosolic calcium ions bind ANO2 and increase the transport of chloride ions by ANO2 from the cytosol to the extracellular region (inferred from mouse homologs in Pifferi et al. 2009, Stephan et al. 2009). The translocations of ions across the plasma membrane causes depolarization of the neuron yielding a receptor potential and action potential that is transmitted to the olfactory bulb of the brain."
BMGC_PW1052,BMG_PW3487,,,"In L cells of the intestine the transcription factors TCF-4 (TCF7L2) and Beta-catenin form a heterodimer and bind the G2 enhancer of the Proglucagon gene GCG,activating its transcription to yield Proglucagon mRNA and, following translation, Proglucagon protein. The prohormone convertase PC1 present in the secretory granules of L cells cleaves Proglucagon at two sites to yield mostly Glucagon-like Peptide-1 (7-36) with a small amount of Glucagon-like Peptide-1 (7-37). Glucagon-like Peptide-1 (7-36 and 7-37) (GLP-1) is secreted into the bloodstream in response to glucose, fatty acids, insulin, leptin, gastrin-releasing peptide, cholinergic transmitters, beta-adrenergic transmitters, and peptidergic transmitters. The half-life of GLP-1 in the bloodstream is determined by Dipeptidyl Peptidase IV, which cleaves 2 amino acids at the amino terminus of GLP-1, rendering it biologically inactive."
BMGC_PW1053,BMG_PW3488,,,"By definition cells have a critical separation between inner (cytoplasmic) and outer (extracellular) compartments. This separation provides for protection, gradient assembly, and environmental control but at the same time isolates the interior compartments of the cell from energy resources, oxygen, and raw materials. Cells have evolved a myriad of mechanisms to regulate, and enable transportation of small molecules ascross plasma membranes and between cellular organelle compartments within cells."
BMGC_PW1054,BMG_PW3489,,,"The ATP-binding cassette (ABC) superfamily of active transporters involves a large number of functionally diverse transmembrane proteins. They transport a variety of compounds through membranes against steep concentration gradients at the cost of ATP hydrolysis. These substrates include amino acids, lipids, inorganic ions, peptides, saccharides, peptides for antigen presentation, metals, drugs, and proteins. The ABC transporters not only move a variety of substrates into and out of the cell, but are also involved in intracellular compartmental transport. Energy derived from the hydrolysis of ATP is used to transport the substrate across the membrane against a concentration gradient. Human genome contains 48 ABC genes; 16 of these have a known function and 14 are associated with a defined human disease (Dean et al. 2001, Borst and Elferink 2002, Rees et al. 2009)."
BMGC_PW1055,BMG_PW3490,,,"A classic example of bifunctional transcription factors is the family of Nuclear Receptor (NR) proteins. These are DNA-binding transcription factors that bind certain hormones, vitamins, and other small, diffusible signaling molecules. The non-liganded NRs recruit specific corepressor complexes of the NCOR/SMRT type, to mediate transcriptional repression of the target genes to which they are bound. During signaling, ligand binding to a specific domain the NR proteins induces a conformational change that results in the exchange of the associated CoR complex, and its replacement by a specific coactivator complex of the TRAP / DRIP / Mediator type. These coactivator complexes typically nucleate around a MED1 coactivator protein that is directly bound to the NR transcription factor. A general feature of the 49 human NR proteins is that in the unliganded state, they each bind directly to an NCOR corepressor protein, either NCOR1 or NCOR2 (NCOR2 was previously named ""SMRT""). This NCOR protein nucleates the assembly of additional, specific corepressor proteins, depending on the cell and DNA context. The NR-NCOR interaction is mediated by a specific protein interaction domain (PID) present in the NRs that binds to specific cognate PID(s) present in the NCOR proteins. Thus, the human NRs each take part in an NR-NCOR binding reaction in the absence of binding by their ligand. A second general feature of the NR proteins is that they each contain an additional, but different PID that mediates specific binding interactions with MED1 proteins. In the ligand-bound state, NRs each take part in an NR-MED1 binding reaction to form an NR-MED1 complex. The bound MED1 then functions to nucleate the assembly of additional specific coactivator proteins, depending on the cell and DNA context, such as what specific target gene promoter they are bound to, and in what cell type. The formation of specific MED1-containing coactivator complexes on specific NR proteins has been well-characterized for a number of the human NR proteins (see Table 1 in (Bourbon, 2004)). For example, binding of thyroid hormone (TH) to the human TH Receptor (THRA or THRB) was found to result in the recruitment of a specific complex of Thyroid Receptor Associated Proteins - the TRAP coactivator complex - of which the TRAP220 subunit was later identified to be the Mediator 1 (MED1) homologue. Similarly, binding of Vitamin D to the human Vitamin D3 Receptor was found to result in the recruitment of a specific complex of D Receptor Interacting Proteins - the DRIP coactivator complex, of which the DRIP205 subunit was later identified to be human MED1."
BMGC_PW1056,BMG_PW3492,,,"G protein-coupled receptors (GPCRs) are classically defined as the receptor, G-protein and downstream effectors, the alpha subunit of the G-protein being the primary signaling molecule. However, it has become clear that this greatly oversimplifies the complexities of GPCR signaling (Gurevich & Gurevich 2008). The beta:gamma G-protein dimer is also involved in downstream signaling (Smrcka 2008) and some receptors form metastable complexes with accessory proteins such as the arrestins. GPCRs are involved in many diverse signaling events (Kristiansen 2004), using a variety of pathways that include modulation of adenylyl cyclase, phospholipase C, the mitogen activated protein kinases (MAPKs), extracellular signal regulated kinase (ERK) c-Jun-NH2-terminal kinase (JNK) and p38 MAPK. Regulator of G-protein Signalling (RGS) proteins can directly inhibit the activity of the G-alpha subunit (Soundararajan et al. 2008). The general function of the G alpha-s subunit (Gs) is to activate adenylate cyclase (Tesmer et al. 1997), which in turn produces cyclic-AMP (cAMP), leading to the activation of cAMP-dependent protein kinases (often referred to collectively as Protein Kinase A). The signal from the ligand-stimulated GPCR is amplified because the receptor can activate several Gs heterotrimers before it is inactivated. The classical signalling mechanism for G alpha-i (Gi) is inhibition of the cAMP dependent pathway through inhibition of adenylate cyclase (Dessauer et al. 2002). Decreased production of cAMP results in decreased activity of cAMP-dependent protein kinases. G alpha-z (Gz) is a member of the Gi family. Unlike other Gi family members it is pertussis toxin-insensitive. Gz interacts with Rap1 GTPase activating protein (RAP1GAP) to attenuate Rap1 signaling. The classic signalling route for G alpha-q (Gq) is activation of phospholipase C beta, leading to phosphoinositide hydrolysis, calcium mobilization and protein kinase C activation. This provides a path to calcium-regulated kinases and phosphatases, GEFs, MAP kinases and many other proteins. The G-alpha-12/13 (G12/13) family is probably the least well characterized, at least in part because G12/13 coupling is more difficult to determine than for other subtypes, G12/13 is best known for involvement in the processes of cell proliferation and morphology, such as stress fiber and focal adhesion formation. Interactions with Rho guanine nucleotide exchange factors (RhoGEFs) are thought to mediate many of these processes. (Buhl et al.1995, Sugimoto et al. 2003). Activation of Rho or the regulation of events through Rho is often taken as evidence of G12/13 signaling. Receptors that are coupled with G12/13 invariably couple with one or more other G protein subtypes, usually Gq."
BMGC_PW1057,BMG_PW3493,,,"The vasopressins are peptide hormones consisting of nine amino acids (nonapeptides). They include arginine vasopressin (AVP; anti-diuretic hormone, ADH) and oxytocin. They are synthesized in the hypothalamus from a precursor and released from stores in the posterior pituitary into the blood stream. One of the most important roles of vasopressins is the regulation of water retention in the body. Oxytocin is important in uterine contraction during birth. The vasopressins act via AVP and oxytocin receptors. These are connected to G proteins which act as second messengers and convey the signal inside the cell."
BMGC_PW1058,BMG_PW3494,,,"Optimal activation of T lymphocytes requires a carefully orchestrated interplay between two key signals. The first signal originates from the T cell receptor (TCR) recognizing a specific antigen. However, this initial encounter is insufficient on its own. A crucial ""costimulatory"" signal is needed for full T cell activation, delivered by the engagement of costimulatory receptors, such as CD28, on the T cell surface with their corresponding ligands on antigen-presenting cells (APCs) (Chen & Flies 2013, Acuto et al. 2003, Slavik et al. 1999). The CD28 superfamily is central to costimulation, encompassing a diverse group of receptors including CD28, CTLA-4, ICOS, PD-1, and BTLA. These receptors have both positive and negative influences on T cell activation. CD28 and ICOS provide a positive boost, while CTLA-4, PD-1, and BTLA act as inhibitory brakes. CD28 and CTLA-4 bind to B7 family ligands CD80 (B7.1) and CD86 (B7.2), with CD28 delivering stimulatory signals and CTLA-4 providing inhibitory signals. ICOS interacts with ICOS ligand (ICOS-L), enhancing T cell activation and function. PD-1 binds to PD-L1 and PD-L2, mediating inhibitory signals that modulate the immune response. BTLA engages with HVEM (Herpesvirus entry mediator), transmitting inhibitory signals. This balance between stimulatory and inhibitory signals is essential, allowing the immune system to mount effective responses against pathogens while preventing the induction of T cell unresponsiveness and apoptosis (Chen & Flies 2013, Sharpe & Freeman 2002, Carreno & Collins 2002). The expression of these receptors varies: CD28 is constantly present on naive T cells, whereas CTLA-4 expression depends on prior CD28 engagement. ICOS, PD-1, and BTLA are induced only after initial T cell stimulation. These variations in expression ensure precise regulation of T cell responses at different stages of activation (Sharpe & Freeman 2002). The receptors themselves also exhibit structural differences. CD28, CTLA-4, and ICOS share a single extracellular domain resembling an immunoglobulin molecule (IgV-like). In contrast, BTLA has a distinct structure with an IgC-like domain. Similarly, the costimulatory ligands, such as B7-1 and B7-2, have unique structural features that enable specific interactions with their partner receptors."
BMGC_PW1059,BMG_PW3496,,,"CD28 signaling plays a critical role in shaping immune responses by ensuring effective T-cell activation and enhancing T-cell survival and proliferation. When CD28 engages its ligands, B7-1 (CD80) and B7-2 (CD86), on antigen-presenting cells, it provides an essential secondary signal that complements T-cell receptor (TCR) activation. This costimulatory signal leads to the production of interleukin-2 (IL-2), which supports the clonal expansion of T cells, promoting both their proliferation and survival by initiating anti-apoptotic pathways (Ribot et al. 2012, Alegre et al. 2001). The cytoplasmic tail of CD28, upon ligand binding, undergoes phosphorylation by Src family kinases like LCK and FYN, triggering downstream signaling pathways involving PI3K, VAV-1, Tec family kinases, AKT, and other adaptor proteins (Sharpe & Freeman 2002; Chen & Flies 2013)."
BMGC_PW1060,BMG_PW3497,,,"CD28-mediated PI3K signaling plays a crucial role in augmenting T cell activation and survival. Phosphoinositide 3-kinases (PI3Ks) are lipid kinases that can be activated downstream of various receptors, including the T-cell receptor (TCR), co-stimulatory receptors like CD28, and cytokine or chemokine receptors. The role of PI3K signaling differs depending on the upstream receptor involved. CD28, specifically, contains a YMNM consensus motif in its cytoplasmic tail, which serves as a binding site for the p85 regulatory subunit of PI3K. When CD28 is engaged, it promotes the recruitment of PI3K, complementing PI3K activation downstream of the TCR. This recruitment triggers the conversion of phosphatidylinositol (4,5)-bisphosphate (PIP2) to phosphatidylinositol (3,4,5)-trisphosphate (PIP3) at the plasma membrane, which serves as a docking site for multiple signaling proteins. Among these, the guanine nucleotide exchange factor VAV and the serine/threonine kinase AKT (also known as protein kinase B, PKB) are key mediators of CD28-induced costimulatory signals. PI3K activation through CD28 promotes cytokine transcription (e.g., IL-2), T cell survival via anti-apoptotic pathways, cell cycle progression, and metabolic changes necessary for T cell growth (Riha and Rudd. 2010, Miller et al. 2009, Han et al. 2012)."
BMGC_PW1061,BMG_PW3498,,,"CD28 binds to several intracellular signaling proteins, including PI3 kinase, Grb2, Gads, and ITK, which are crucial for amplifying the T cell activation signal initiated by the T-cell receptor (TCR). Grb2, in particular, works in tandem with Vav1 to enhance the activation of NFAT and AP-1 transcription factors, critical regulators of gene expression during T cell activation. CD28 costimulation significantly extends the duration and intensity of Vav1 phosphorylation and its localization at the plasma membrane compared to TCR activation alone, indicating that CD28 provides a sustained signal that enhances T cell responsiveness (Hehner et al. 2000). Vav1 plays a pivotal role in transducing signals from both TCR and CD28 to multiple downstream pathways, with a direct impact on cytoskeletal rearrangements. Upon activation, Vav1 triggers the small GTPases Rac1 and Cdc42, which lead to the activation of mitogen-activated protein kinases (MAPKs) like JNK and p38. In the context of CD28 signaling, these pathways are essential for regulating the expression of cytokines and promoting T cell proliferation and survival (Laura Inés Salazar-Fontana et al. 2003). Additionally, Vav1's involvement in CD28 costimulation is critical for several other cellular processes, including calcium flux, ERK MAPK activation, NF-κB signaling, and the inside-out activation of the integrin LFA-1. This enhances T cell adhesion, clustering, and polarization, ultimately contributing to more effective immune responses. Thus, CD28 costimulation ensures that Vav1-mediated signals are robustly sustained, promoting optimal T cell activation and function (Hehner et al. 2000)."
BMGC_PW1062,BMG_PW3499,,,The orphan G protein-coupled receptors mentioned here regulate sleep and appetite.
BMGC_PW1063,BMG_PW3500,,,"Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an immune checkpoint molecule predominantly expressed on the surface of activated T cells and regulatory T (Treg) cells. It plays a critical role in inhibiting T-cell activation and maintaining immune homeostasis (Alegre et al. 2001). After acctivation of T lymphocytes through their antigen receptor (TCR) induces the upregulation of CTLA-4 expression. CTLA-4 engagement alongside TCR activation inhibits T cell responses through two primary mechanisms: competing with CD28 for B7 binding to reduce costimulation, and delivering a negative signal directly into the T cells. It has been reported that phosphotyrosine-dependent recruitment of the SHP-2 phosphatase to CTLA-4 inhibits T cell activation and expansion by dephosphorylation of CD3/TCR chains. CTLA-4 inhibits T cell activation through several mechanisms, including the reduction of IL-2 production and expression, as well as by arresting T cells in the G1 phase of the cell cycle (Greenwald et al. 2002). This checkpoint molecule not only impacts the T cells that express it but also exerts a dominant regulatory influence on the proliferation of other T cells. This ability to limit the proliferation of surrounding T cells is crucial in preventing autoreactivity and maintaining immune tolerance, ensuring that the immune system does not inadvertently target the body's own tissues. Due to its ability to modulate immune responses, CTLA-4 has emerged as a significant therapeutic target for managing conditions such as cancer, autoimmune diseases, and transplant rejection (Tivol et al. 1995, Chambers et al. 1997, Rudd and Schneider 2003)."
BMGC_PW1064,BMG_PW3501,,,"Phytanic acid arises through ruminant metabolism of chlorophyll and enters the human diet as a constituent of dairy products (Baxter 1968). It can act as an agonist for PPAR and other nuclear hormone receptors, but its normal role in human physiology, if any, is unclear. It is catabolized via a five-step alpha-oxidation reaction sequence that yields pristanoyl-CoA, which is turn is a substrate for beta-oxidation. These reactions take place in the peroxisomal matrix and their failure is associated with Refsum disease (Wanders et al. 2003)."
BMGC_PW1065,BMG_PW3502,,,"Glyoxylate is generated in the course of glycine and hydroxyproline catabolism and can be converted to oxalate. In humans, this process takes place in the liver. Defects in two enzymes of glyoxylate metabolism, alanine:glyoxylate aminotransferase (AGXT) and glycerate dehydrogenase/glyoxylate reductase (GRHPR), are associated with pathogenic overproduction of oxalate (Danpure 2005). The reactions that interconvert glycine, glycolate, and glyoxylate and convert glyoxylate to oxalate have been characterized in molecular detail in humans. A reaction sequence for the conversion of hydroxyproline to glyoxylate has been inferred from studies of partially purified extracts of rat and bovine liver but the enzymes involved in the corresponding human reactions have not been identified."
BMGC_PW1066,BMG_PW3503,,,"Pristanoyl-CoA, generated in the peroxisome by alpha-oxidation of dietary phytanic acid, is further catabolized by three cycles of peroxisomal beta-oxidation to yield 4,8-dimethylnonanoyl-CoA, acetyl-CoA and two molecules of propionyl-CoA. These molecules in turn are converted to carnitine conjugates, which can be transported to mitochondria (Wanders and Waterham 2006, Verhoeven et al. 1998, Ferdinandusse et al. 1999)."
BMGC_PW1067,BMG_PW3505,,,"Programmed cell death protein 1 (PD-1) is a crucial inhibitory receptor that regulates T cell receptor (TCR) signaling and plays a vital role in maintaining immune homeostasis. PD-1 exerts its suppressive effects both directly, by inhibiting early activation events that are otherwise enhanced by co-stimulatory signals like CD28, and indirectly, by reducing interleukin-2 (IL-2) production, which is essential for T cell proliferation and survival. Upon ligation, PD-1 inhibits the expression of key survival and differentiation factors, such as Bcl-xL, and downregulates transcription factors that are central to effector T cell function, including GATA-3, T-bet, and Eomes. Mechanistically, PD-1 recruits the tyrosine phosphatases SHP-1 and SHP-2 to the immune synapse, leading to the dephosphorylation of critical signaling molecules like the CD3-zeta chain, PI3K, and AKT, thereby attenuating TCR signaling and inhibiting T cell activation and function (Keir et al. 2008)."
BMGC_PW1068,BMG_PW3506,,,"Unfolded actins and tubulins bound to prefoldin are transferred to CCT via a docking mechanism (McCormack and Willison, 2001)."
BMGC_PW1069,BMG_PW3507,,,"In the case of actin and tubulin folding, and perhaps other substrates, the emerging polypeptide chain is transferred from the ribosome to TRiC via Prefoldin (Vainberg et al., 1998)."
BMGC_PW1070,BMG_PW3508,,,"TriC/CCT forms a binary complex with unfolded alpha- or beta-tubulin (Frydman et al., 1992; Gao et al., 1993). The tubulin folding intermediates produced by TriC are unstable (Gao et al., 1993). Five additional protein cofactors (cofactor A-E) are required for the generation of properly folded alpha- and beta-tubulin and for the formation of alpha/beta-tubulin heterodimers (Gao et al., 1993) (Tian et al., 1997, Cowan and Lewis 2001)."
BMGC_PW1071,BMG_PW3509,,,"Alpha and beta tubulin folding intermediates are formed through ATP-dependent interaction with TriC/CCT. In order to form a functional heterodimer, these folding intermediates undergo a series of interactions with five proteins: (cofactors A-E) following release from TriC/CCT (reviewed in Cowan and Lewis et al., 2001). These interactions are described in the reactions below. Ultimately, alpha tubulin, when associated with cofactor E, interacts with cofactor D-bound beta-tubulin. The entry of cofactor C into this complex results in the discharge of native heterodimer triggered by GTP hydrolysis in beta tubulin (Tian et al., 1997)."
BMGC_PW1072,BMG_PW3510,,,"Nucleotide-independent transfer of beta-actin from prefoldin to CCT occurs when prefoldin binds to CCT (Vainberg et al., 1998). Following ATP- dependent folding within CCT (Gao et al., 1992), beta-actin is released as a soluble, monomeric protein."
BMGC_PW1073,BMG_PW3511,,,"The eukaryotic chaperonin TCP-1 ring complex (TRiC/ CCT) plays an essential role in the folding of a subset of proteins prominent among which are the actins and tubulins (reviewed in Altschuler and Willison, 2008). CCT/TRiC is an example of a type II chaperonin, defined (in contrast to type I) as functioning in the absence of a cochaperonin. TriC/CCT is a multisubunit toroidal complex that forms a cylinder containing two back-to-back stacked rings enclosing a cavity where substrate folding occurs in an ATP dependent process (reviewed in Altschuler and Willison, 2008 ). CCT/TriC contains eight paralogous subunits that are conserved throughout eukaryotic organisms (Leroux and Hartl 2000; Archibald et al. 2001; Valpuesta et al. 2002). CCT-mediated folding of non-native substrate protein involves capture through hydrophobic contacts with multiple chaperonin subunits followed by transfer of the protein into the central ring cavity where it folds. Although folding is initiated within this central cavity, only 5%-20% of proteins that are released have partitioned to the native state. The remaining portion is then recaptured by other chaperonin molecules (Cowan and Lewis 2001). This cycling process may be repeated multiple times before a target protein partitions to the native state. In the cell, binding to CCT occurs via presentation of target protein bound to upstream chaperones. During translation, the emerging polypeptide chain may be transferred from the ribosome to CCT via the chaperone Prefoldin (Vainberg et al., 1998) or the Hsp70 chaperone machinery (Melville et al., 2003). While the majority of CCT substrates ultimately partition to the native state as soluble, monomeric proteins, alpha and beta tubulin are unusual in that they require additional cofactors that are required to assemble the tubulin heterodimer (Cowan and Lewis 2001)."
BMGC_PW1074,BMG_PW3512,,,"TRiC has broad recognition specificities, but in the cell it interacts with only a defined set of substrates (Yam et al. 2008). Many of its substrates that are targeted during biosynthesis are conserved between mammals and yeast (Yam et al. 2008)."
BMGC_PW1075,BMG_PW3513,,,"Muscarinic acetylcholine (mAChRs) receptors were so named because they are more sensitive to muscarine than to nicotine (Ishii M and Kurachi Y, 2006). Their counterparts are nicotinic acetylcholine receptors (nAChRs), ion channels receptors that are also important in the autonomic nervous system. Many drugs can manipulate these two distinct receptors by acting as selective agonists or antagonists. mAChRs bind to the bioamine acetylcholine, have a widespread tissue distribution and are involved in the control of numerous central and peripheral physiological responses, particularly voluntary muscle contraction. They are also major targets for drugs in human diseases such as Alzheimer's, Parkinson's and schizophrenia. This family of G-protein coupled receptors consists of five members designated M1-M5 and are sub-divided into two groups based on their primary coupling to G proteins. M2 and M4 receptors couple to Gi/o proteins and M1, M3 and M5 receptors couple to Gq/11 proteins (Caulfield MP and Birdsall NJ, 1998)."
BMGC_PW1076,BMG_PW3514,,,"Histamine is a biogenic amine involved in local immune responses, regulation of gut function and neurotransmission. It exerts its actions by binding to histamine receptors. There are four receptors in humans, H1-H4 (Hill SJ et al, 1997)."
BMGC_PW1077,BMG_PW3515,,,"Serotonin (5-HT) is a monoamine neurotransmitter that plays an important role as a modulator of anger, aggression, body temperature, mood, sleep, sexuality, appetite, metabolism, as well as stimulating vomiting. Several classes of drugs target the 5-HT system including some antidepressants, antipsychotics, anxiolytics, antiemetics and antimigraine drugs. The activity of 5-HT is modulated by 5-HT receptors, made up of seven families (5-HT1-7). All but 5-HT3 (ligand-gated ion channel) are GPCRs and these receptors bind different G proteins resulting in differing outcomes (Hoyer D et al, 1994; Kitson SL, 2007)."
BMGC_PW1078,BMG_PW3516,,,"The adrenoceptors (adrenergic receptors) are targets for the catecholamines adrenaline (epinephrine) and noradrenaline (norepinephrine). These receptors are widespread in the body and binding of catecholamines produces a sympathetic response ('flight-or-fight response') resulting in increased heart rate, pupil dilation and energy mobilization amongst other responses. There are three major types of adrenoceptor, alpha1, alpha2 and beta. Each type is thought to have three subtypes; alpha1 (1A,1B,1D), alpha2 (2A,2B,2C) and beta (1,2,3) (Bylund DB et al, 1994)."
BMGC_PW1079,BMG_PW3517,,,"Glycosylation is the most abundant modification of proteins, variations of which occur in all living cells. Glycosylation can be further categorized into N-linked (where the oligosaccharide is conjugated to Asparagine residues) and O-linked glycosylation (where the oligosaccharide is conjugated to Serine, Threonine and possibly Tyrosine residues). Within the family of O-linked glycosylation, the oligosaccharides attached can be further categorized according to their reducing end residue: GalNAc (often described as mucin-type, due to the abundance of this type of glycosylation on mucins), Mannose and Fucose. This section reviews currently known congenital disorders of glycosylation associated with defects of protein O-glycosylation (Cylwik et al. 2013, Freeze et al. 2014)."
BMGC_PW1080,BMG_PW3518,,,"In humans, the catabolism of phytanate, pristanate, and very long chain fatty acids as well as the first four steps of the biosynthesis of plasmalogens are catalyzed by peroxisomal enzymes. Defects in any of these enzymes or in the assembly of peroxisomes are associated with severe developmental disorders (Wanders and Watherham 2006)."
BMGC_PW1081,BMG_PW3519,,,"Signal regulatory protein alpha (SIRPA, SHPS1, CD172a) is a transmembrane protein expressed mostly on myeloid cells. CD47, a widely expressed transmembrane protein, is a ligand for SIRP alpha, with the two proteins constituting a cell-cell communication system. The interaction of SIRPA with CD47 is important for the regulation of migration and phagocytosis. SIRPA functions as a docking protein to recruit and activate PTPN6 (SHP-1) or PTPN11 (SHP-2) at the cell membrane in response to extracellular stimuli. SIRPA also binds other intracellular proteins including the adaptor molecules Src kinase-associated protein (SKAP2 SKAP55hom/R), Fyn-binding protein/SLP-76-associated phosphoprotein (FYB/SLAP-130) and the tyrosine kinase PYK2. SIRPA also binds the extracellular proteins, surfactant-A (SP-A) and surfactant-D (SP-D). The SIRP family members SIRPB and SIRPG show high sequence similarity and similar extracellular structural topology, including three Ig domains, but their ligand binding topology might differ. SIRPB is expressed on myeloid cells, including monocytes, granulocytes and DCs. It has no known natural ligand. SIRPG can bind CD47 but with lower affinity than SIRPA."
BMGC_PW1082,BMG_PW3520,,,"Eicosanoids, derived from polyunsaturated 20-carbon fatty acids, are paracrine and autocrine regulators of inflammation, smooth muscle contraction, and blood coagulation. The actions of eicosanoids are mediated by eicosanoid receptors, most of which are GPCRs. There are four types of eicosanoid GPCRs in humans; leukotriene, lipoxin (Brink C et al, 2003), prostanoid (Coleman RA et al, 1994) and oxoeicosanoid (Brink C et al, 2004) receptors."
BMGC_PW1083,BMG_PW3521,,,"Leukotriene receptors bind leukotriene ligands. There are four types of receptor in humans; two for leukotriene B4 and two for cysteinyl leukotrienes (Brink C et al, 2003)."
BMGC_PW1084,BMG_PW3522,,,"Fatty acid cyclo-oxygenase (COX) converts arachidonic acid to prostaglandin H2 (PGH2) from which the prostanoids PGD2, PGE2, PGF2alpha, PGI2 (prostacyclin) and thromboxane A2 (TXA2) are derived. Based on the agonist potencies, five prostanoid receptors are recognized and correspondingly named DP, EP, FP, IP and TP receptors (Coleman RA et al, 1994). Additionally, EP receptors contains four subtypes, termed EP1, EP2, EP3 and EP4; the DP receptor also has two subtypes, DP1 and DP2 (CRTH2)."
BMGC_PW1085,BMG_PW3523,,,"Nitric Oxide (NO) inhibits smooth muscle cell proliferation and migration, oxidation of low-density lipoproteins, and platelet aggregation and adhesion. It can stimulate vasodilatation of the endothelium, disaggregation of preformed platelet aggregates and inhibits activated platelet recruitment to the aggregate. NO is synthesized from L-arginine by a family of isoformic enzymes known as nitric oxide synthase (NOS). Three isoforms, namely endothelial, neuronal, and inducible NOS (eNOS, nNOS, and iNOS, respectively), have been identified. The eNOS isoform is found in the endothelium and platelets. NO regulation of cyclic guanosine-3,5-monophosphate (cGMP), via activation of soluble guanylate cyclase, is the principal mechanism of negative control over platelet activity. Defects in this control mechanism have been associated with platelet hyperaggregability and associated thrombosis."
BMGC_PW1086,BMG_PW3524,,,"Co-activation of P2Y1 and P2Y12 is necessary for complete platelet activation. P2Y1 is coupled to Gq and helps trigger the release of calcium from internal stores, leading to weak and reversible platelet aggregation. P2Y12 is Gi coupled, inhibiting adenylate cyclase, leading to decreased cAMP, a consequent decrease in cAMP-dependent protein kinase activity which increases cytoplasmic [Ca2+], necessary for activation (Woulfe et al. 2001). In activated platelets, P2Y12 signaling is required for the amplification of aggregation induced by all platelet agonists including collagen, thrombin, thromboxane, adrenaline and serotonin. P2Y12 activation causes potentiation of thromboxane generation, secretion leading to irreversible platelet aggregation and thrombus stabilization."
BMGC_PW1087,BMG_PW3525,,,"PI3K gamma (PI3KG) is a heterodimer consisting of a p110 catalytic subunit associated with a regulatory p101 or p84 subunit. PI3KG is most highly expressed in neutrophils, where the p101 form predominates (approximately 95%). G beta:gamma recruits PI3KG to the plasma membrane, both activating PI3KG and providing access to its substrate PIP2, which is converted to PIP3."
BMGC_PW1088,BMG_PW3526,,,"Metabolism of proteins, as annotated here, covers the full life cycle of a protein from its synthesis to its posttranslational modification and degradation, at various levels of specificity. Protein synthesis is accomplished through the process of Translation of an mRNA sequence into a polypeptide chain. Protein folding is achieved through the function of molecular chaperones which recognize and associate with proteins in their non-native state and facilitate their folding by stabilizing the conformation of productive folding intermediates (Young et al. 2004). Following translation, many newly formed proteins undergo Post-translational protein modification, essentially irreversible covalent modifications critical for their mature locations and functions (Knorre et al. 2009), including gamma carboxylation, synthesis of GPI-anchored proteins, asparagine N-linked glycosylation, O-glycosylation, SUMOylation, ubiquitination, deubiquitination, RAB geranylgeranylation, methylation, carboxyterminal post-translational modifications, neddylation, and phosphorylation. Peptide hormones are synthesized as parts of larger precursor proteins whose cleavage in the secretory system (endoplasmic reticulum, Golgi apparatus, secretory granules) is annotated in Peptide hormone metabolism. After secretion, peptide hormones are modified and degraded by extracellular proteases (Chertow, 1981 PMID:6117463). Protein repair enables the reversal of damage to some amino acid side chains caused by reactive oxygen species. Pulmonary surfactants are lipids and proteins that are secreted by the alveolar cells of the lung that decrease surface tension at the air/liquid interface within the alveoli to maintain the stability of pulmonary tissue (Agassandian and Mallampalli 2013). Nuclear regulation, transport, metabolism, reutilization, and degradation of surfactant are described in the Surfactant metabolism pathway. Amyloid fiber formation, the accumulation of mostly extracellular deposits of fibrillar proteins, is associated with tissue damage observed in numerous diseases including late phase heart failure (cardiomyopathy) and neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's."
BMGC_PW1089,BMG_PW3527,,,"In the initial response to injury, platelets adhere to damaged blood vessels, responding to the exposure of collagen from the vascular epithelium. Once adhered they degranulate, releasing stored secondary agents such as ADP and ATP, and synthesized thromboxane A2. These amplify the response, activating and recruiting further platelets to the area and promoting platelet aggregation. Adenosine nucleotides secreted following platelet activation signal through P2 purinergic receptors on the platelet membrane. ADP activates P2Y1 and P2Y12 while ATP activates the ionotropic P2X1 receptor (Kunapuli et al. 2003). Activation of these receptors initiates a complex signaling cascade that ultimately results in platelet activation and thrombus formation (Kahner et al. 2006). ADP stimulation of P2Y1 and P2Y12 involves signaling via both the alpha and gamma:beta components of the heterotrimeric G-protein (Hirsch et al. 2001, 2006)."
BMGC_PW1090,BMG_PW3528,,,"Prostacyclin (PGI2) is continuously produced by healthy vascular endothelial cells. It inhibits platelet activation through interaction with the Gs-coupled receptor PTGIR, leading to increased cAMP, a consequent increase in cAMP-dependent protein kinase activity which prevents increases of cytoplasmic [Ca2+] necessary for activation (Woulfe et al. 2001). PGI2 is also an effective vasodilator. These effects oppose the effects of thromboxane (TXA2), another eicosanoid, creating a balance of blood circulation and platelet activation."
BMGC_PW1091,BMG_PW3529,,,"Multiple EPHB receptors contribute directly to dendritic spine development and morphogenesis. These are more broadly involved in post-synaptic development through activation of focal adhesion kinase (FAK) and Rho family GTPases and their GEFs. Dendritic spine morphogenesis is a vital part of the process of synapse formation and maturation during CNS development. Dendritic spine morphogenesis is characterized by filopodia shortening followed by the formation of mature mushroom-shaped spines (Moeller et al. 2006). EPHBs control neuronal morphology and motility by modulation of the actin cytoskeleton. EPHBs control dendritic filopodia motility, enabling synapse formation. EPHBs exert these effects through interacting with the guanine exchange factors (GEFs) such as intersectin and kalirin. The intersectin-CDC42-WASP-actin and kalirin-RAC-PAK-actin pathways have been proposed to regulate the EPHB receptor mediated morphogenesis and maturation of dendritic spines in cultured hippocampal and cortical neurons (Irie & Yamaguchi 2002, Penzes et al. 2003). EPHBs are also involved in the regulation of dendritic spine morphology through FAK which activates the RHOA-ROCK-LIMK-1 pathway to suppress cofilin activity and inhibit cofilin-mediated dendritic spine remodeling (Shi et al. 2009)."
BMGC_PW1092,BMG_PW3530,,,"EPH/Ephrin signaling is coupled to Rho family GTPases such as Rac, Rho and Cdc42 that connect bidirectional receptor-ligand interactions to changes in the actin cytoskeleton (Noren & Pasquale 2004, Groeger & Nobes 2007). RHOA regulates actin dynamics and is involved in EPHA-induced growth cone collapse. This is mediated by ephexins. Ephexin, a guanine nucleotide exchange factor for Rho GTPases, interacts with the EPHA kinase domain and its subsequent activation differentially affects Rho GTPases, such that RHOA is activated, whereas Cdc42 and Rac1 are inhibited. Activation of RHOA, and inhibition of Cdc42 and Rac, shifts actin cytoskeleton to increased contraction and reduced expansion leading to growth-cone collapse (Shamah et al. 2001, Sahin et al. 2005). The activation of EPH receptors in growing neurons typically, but not always, leads to a growth cone collapse response and retraction from an ephrin-expressing substrate (Poliakov et al. 2004, Pasquale 2005). EPHA-mediated repulsive responses prevent axons from growing into regions of excessive ephrin-A concentration, such as the posterior end of the superior colliculus (Pasquale 2005)."
BMGC_PW1093,BMG_PW3531,,,"The interaction between ephrin (EFN) ligands and EPH receptors results not only in forward signaling through the EPH receptor, but also in 'reverse' signaling through the EFN ligand itself. Reverse signaling through EFNB is required for correct spine morphogenesis and proper path-finding of corpus callosum and dorsal retinal axons. The molecular mechanism by which EFNBs transduce a reverse signal involves phosphorylation of multiple, conserved tyrosines on the intracellular domain of B-type ephrins, facilitating binding of the SH2/SH3 domain adaptor protein GRB4 and subsequent cytoskeletal remodeling (Bruckner et al. 1997, Cowan & Henkemeyer 2001, Lu et al. 2001). The other mechanism of reverse signaling involves the C-terminus PSD-95/Dlg/ZO-1 (PDZ)-binding motif of EFNBs which recruits various PDZ domain containing proteins. Phosphorylation and PDZ-dependent reverse signaling by ephrin-B1 have each been proposed to play important roles in multiple contexts in development and disease (Bush & Soriano 2009)."
BMGC_PW1094,BMG_PW3532,,,"Despite high-affinity multimeric interaction between EPHs and ephrins (EFNs), the cellular response to EPH-EFN engagement is usually repulsion between the two cells and signal termination. These repulsive responses induce an EPH receptor-expressing cell to retract from an ephrin-expressing cell after establishing initial contact. The repulsive responses mediated by EPH receptors in the growth cone at the leading edge of extending axons and in axonal collateral branches contribute to the formation of selective neuronal connections. It is unclear how high affinity trans-cellular interactions between EPHs and ephrins are broken to convert adhesion into repulsion. Two possible mechanisms have been proposed for the repulsion of EPH-EFN bearing cells: the first one involves regulated cleavage of ephrin ligands or EPH receptors by transmembrane proteases following cell-cell contact, while the second one is rapid endocytosis of whole EPH:EFN complexes during the retraction of the interacting cells or neuronal growth cones (Egea & Klein 2007, Janes et al. 2005). RAC also plays an essential role during growth cone collapse by promoting actin polymerization that drives membrane internalization by endocytosis (Marston et al. 2003)."
BMGC_PW1095,BMG_PW3533,,,"The classical role of the G-protein beta/gamma dimer was believed to be the inactivation of the alpha subunit, Gbeta/gamma was viewed as a negative regulator of Galpha signalling. It is now known that Gbeta/gamma subunits can directly modulate many effectors, including some also regulated by G alpha."
BMGC_PW1096,BMG_PW3534,,,"AMPA receptors are functionally either Ca permeable or Ca impermeable based on the subunit composition. Ca permeability is determined by GluR2 subunit which undergoes post-transcriptional RNA editing that changes glutamine (Q) at the pore to arginine (R). Incorporation of even a single subunit in the AMPA receptor confers Ca-limiting properties. Ca permeable AMPA receptors permit Ca and Na whereas Ca impermeable AMPA receptors permit only Na. In general, glutamatergic neurons contain Ca impermeable AMPA receptors and GABAergic interneurons contain Ca permeable AMPA receptors. However, some synapses do contain a mixture of Ca permeable and Ca impermeable AMPA receptors. GluR1-4 are encoded by four genes however, alternative splicing generates several functional subunits namely long and short forms of GluR1 and GluR2. GluR4 has long tail only and GluR3 has short tail only. Besides the differences in the tail length, flip/flop isoforms are generated by an interchangeable exon that codes the fourth membranous domain towards the C terminus. The fip/flop isoforms determine rate of desensitization/resensitization and the rate of channel closing. Receptors homomers or heteromers assembled from the combination of GluR1-4 subunits that vary in C tail length and flip/flop versions generates a whole battery of functionally distinct AMPA receptors."
BMGC_PW1097,BMG_PW3535,,,Repetitive presynaptic activity causes long lasting changes in the postsynaptic transmission by changing the type and the number of AMPA receptors. These changes are brought about by trafficking mechanisms that are mainly controlled by activity dependent phosphorylation/desphosphorylation of the GluR1/GluR2 subunits.
BMGC_PW1098,BMG_PW3536,,,"Activated Rac1 bound to plexin-A might modulate actin dynamics through the sequential phosphorylation and activation of PAK, LIMK1 and cofilin."
BMGC_PW1099,BMG_PW3537,,,"Sema3A, a prototypical semaphorin, acts as a chemorepellent or a chemoattractant for axons by activating a receptor complex comprising neuropilin-1 as the ligand-binding subunit and plexin-A1 as the signal-transducing subunit. Sema3A inhibits cell migration by inhibiting integrin ligand-binding activity."
BMGC_PW1100,BMG_PW3538,,,"CRMPs are a small family of plexinA-interacting cytosolic phosphoproteins identified as mediators of Sema3A signaling and neuronal differentiation. After Sema3A activation Plexin-A bound CRMP's undergo phosphorylation by Cdk5, GSK3beta and Fes kinases. Phosphorylation of CRMPs by these kinases blocks the ability of CRMP to bind to tubulin dimers, subsequently induces depolymerization of F-actin, and ultimately leads to growth cone collapse."
BMGC_PW1101,BMG_PW3539,,,"Acetylcholine released by parasympathetic nerve endings in the pancreas causes a potentiation of insulin release when glucose is present at concentrations greater than about 7 mM. Acetylcholine binds the Muscarinic Acetylcholine Receptor M3 on pancreatic beta cells. The binding has two effects: an increase in permeability of the cell to Na+ ions through an unknown mechanism, and the activation of Phospholipase C beta-1 through a heterotrimeric G protein, G(q). After acetylcholine binds the Muscarinic Acetycholine Receptor M3, the receptor activates the G protein Gq by causing the alpha subunit of Gq to exchange GDP for GTP. Activation of Gq in turn activates Phospholipase C beta-1. Phospholipase C beta-1 hydrolyzes the phosphodiester bond at the third position of phosphoinositol 4,5-bisphosphate, producing diacylglycerols (DAG) and inositol 1,4,5-trisphosphate. DAG remains in the cell membrane and causes Protein Kinase C alpha (PKC alpha) to translocate from the cytosol to the membrane. This results in the activation of PKC alpha which then phosphorylates target proteins on serine and threonine residues. One known target of PKC alpha is Myristoylated Alanine-rich C Kinase Substrate (MARCKS), which is believed to affect vesicle transport and may be responsible for the increased traffic of insulin granules seen in response to acetylcholine. Inositol trisphophate binds a receptor, the IP3 receptor, on calcium stores in the cell (probably the endoplasmic reticulum). The release of calcium into the cytosol stimulates the exocytosis of insulin granules."
BMGC_PW1102,BMG_PW3540,,,"The catecholamines adrenaline (epinephrine) and noradrenaline (norepinephrine) inhibit insulin secretion from pancreatic beta cells. Four effects are seen in the cells: 1. Inhibition of exocytosis of secretory granules, the major effect. 2. Opening of ATP-sensitive potassium channels (KATP channels) and repolarization of the cell. 3. Closing of L-type voltage-dependent calcium channels and inhibition of calcium influx. 4. Inhibition of adenylyl cyclase activity. The first event in adrenaline/noradrenaline signaling in beta cells is the binding of adrenaline or noradrenaline to alpha-2 adrenergic receptors, which are G-protein coupled receptors. Binding activates the alpha subunits in heterotrimeric Gi and Go complexes to exchange GDP for GTP, forming the active G alpha:GTP complex. Experiments using specific antibodies against the alpha subunits in mice show that Gi alpha-1, Gi alpha-2, and Go alpha-2 are responsible for adrenergic effects. The exact beta and gamma subunits of the heterotrimeric G-proteins are unknown. After activation by GTP, the heterotrimeric complex dissociates into the G alpha:GTP complex and the beta:gamma complex. The G alpha:GTP complex causes the inhibition of exocytosis by an unknown mechanism that involves protein acylation. This is responsible for most of the observed inhibition of insulin secretion. Additionally, the G alpha:GTP complex activates (opens) KATP channels, allowing the cell to repolarize. The beta:gamma complex inhibits (closes) voltage-dependent calcium channels, reducing the intracellular calcium concentration, and inhibits adenylyl cyclase, reducing the intracellular cAMP concentration."
BMGC_PW1103,BMG_PW3541,,,"Peroxisome proliferator-activated receptor alpha (PPAR-alpha) is the major regulator of fatty acid oxidation in the liver. PPARalpha is also the target of fibrate drugs used to treat abnormal plasma lipid levels. PPAR-alpha is a type II nuclear receptor (its subcellular location does not depend on ligand binding). PPAR-alpha forms heterodimers with Retinoid X receptor alpha (RXR-alpha), another type II nuclear receptor. PPAR-alpha is activated by binding fatty acid ligands, especially polyunsaturated fatty acids having 18-22 carbon groups and 2-6 double bonds. The PPAR-alpha:RXR-alpha heterodimer binds peroxisome proliferator receptor elements (PPREs) in and around target genes. Binding of fatty acids and synthetic ligands causes a conformational change in PPAR-alpha such that it releases the corepressors and binds coactivators (CBP-SRC-HAT complex, ASC complex, and TRAP-Mediator complex) which initiate transcription of the target genes. Target genes of PPAR-alpha participate in fatty acid transport, fatty acid oxidation, triglyceride clearance, lipoprotein production, and cholesterol homeostasis."
BMGC_PW1104,BMG_PW3542,,,"At the center of the mammalian circadian clock is a negative transcription/translation-based feedback loop: The BMAL1:CLOCK/NPAS2 (ARNTL:CLOCK/NPAS2) heterodimer transactivates CRY and PER genes by binding E-box elements in their promoters; the CRY and PER proteins then inhibit transactivation by BMAL1:CLOCK/NPAS2. BMAL1:CLOCK/NPAS2 activates transcription of CRY, PER, and several other genes in the morning. Levels of PER and CRY proteins rise during the day and inhibit expression of CRY, PER, and other BMAL1:CLOCK/NPAS2-activated genes in the afternoon and evening. During the night CRY and PER proteins are targeted for degradation by phosphorylation and polyubiquitination, allowing the cycle to commence again in the morning. Transcription of the BMAL1 (ARNTL) gene is controlled by ROR-alpha and REV-ERBA (NR1D1), both of which are targets of BMAL1:CLOCK/NPAS2 in mice and both of which compete for the same element (RORE) in the BMAL1 promoter. ROR-alpha (RORA) activates transcription of BMAL1; REV-ERBA represses transcription of BMAL1. This mutual control forms a secondary, reinforcing loop of the circadian clock. REV-ERBA shows strong circadian rhythmicity and confers circadian expression on BMAL1. BMAL1 can form heterodimers with either CLOCK or NPAS2, which act redundantly but show different tissue specificity. The BMAL1:CLOCK and BMAL1:NPAS2 heterodimers activate a set of genes that possess E-box elements (consensus CACGTG) in their promoters. This confers circadian expression on the genes. The PER genes (PER1, PER2, PER3) and CRY genes (CRY1, CRY2) are among those activated by BMAL1:CLOCK and BMAL1:NPAS2. PER and CRY mRNA accumulates during the morning and the proteins accumulate during the afternoon. PER and CRY proteins form complexes in the cytosol and these are bound by either CSNK1D or CSNK1E kinases which phosphorylate PER and CRY. The phosphorylated PER:CRY:kinase complex is translocated into the nucleus due to the nuclear localization signal of PER and CRY. Within the nucleus the PER:CRY complexes bind BMAL1:CLOCK and BMAL1:NPAS2, inhibiting their transactivation activity and their phosphorylation. This reduces expression of the target genes of BMAL1:CLOCK and BMAL1:NPAS2 during the afternoon and evening. PER:CRY complexes also traffic out of the nucleus into the cytosol due to the nuclear export signal of PER. During the night PER:CRY complexes are polyubiquitinated and degraded, allowing the cycle to begin again. Phosphorylated PER is bound by Beta-TrCP1, a cytosolic F-box type component of some SCF E3 ubiquitin ligases. CRY is bound by FBXL3, a nucleoplasmic F-box type component of some SCF E3 ubiquitin ligases. Phosphorylation of CRY1 by Adenosine monophosphate-activated kinase (AMPK) enhances degradation of CRY1. PER and CRY are subsequently polyubiquitinated and proteolyzed by the 26S proteasome. The circadian clock is cell-autonomous and some, but not all cells of the body exhibit circadian rhythms in metabolism, cell division, and gene transcription. The suprachiasmatic nucleus (SCN) in the hypothalamus is the major clock in the body and receives its major input from light (via retinal neurons) and a minor input from nutrient intake. The SCN and other brain tissues determine waking and feeding cycles and influence the clocks in other tissues by hormone secretion and nervous stimulation. Independently of the SCN, other tissues such as liver receive inputs from signals from the brain and from nutrients."
BMGC_PW1105,BMG_PW3543,,,Free fatty acids augment the glucose-triggered secretion of insulin. The augmentation is believed to be due to the additive effects of the activation of the free fatty acid receptor 1 (FFAR1 or GPR40) and the metabolism of free fatty acids within the pancreatic beta cell. This module describes each pathway.
BMGC_PW1106,BMG_PW3544,,,"Incretins are peptide hormones produced by the gut that enhance the ability of glucose to stimulate insulin secretion from beta cells in the pancreas. Two incretins have been identified: Glucagon-like Peptide-1 (GLP-1) and Glucose-dependent Insulinotropic Polypeptide (GIP, initially named Gastric Inhibitory Peptide). Both are released by cells of the small intestine, GLP-1 from L cells and GIP from K cells. The control of incretin secretion is complex. Fatty acids, phospholipids, glucose, acetylcholine, leptin, and Gastrin-releasing Peptide all stimulate secretion of GLP-1. Fatty acids and phospholipids are the primary stimulants of secretion of GIP in humans (carbohydrates have more effect in rodents). Incretins secreted into the bloodstream are subject to rapid inactivation by Dipeptidyl Peptidase IV (DPP IV), which confers half-lives of only a few minutes onto GLP-1 and GIP. Inhibitors of DPP IV, for example sitagliptin, are now being used in the treatment of Type 2 diabetes."
BMGC_PW1107,BMG_PW3545,,,"In K cells of the intestine the transcription factors PAX6 and PDX-1 activate transcription of the gene encoding Glucose-dependent Insulinotropic Polypeptide (GIP, first called Gastric Inhibitory Peptide). ProGIP is cleaved in secretory granules by Prohormone Convertase 1 (PC1) at 2 sites to yield mature GIP. In response to fat the GIP is secreted into the bloodstream. The half-life of GIP in the bloodstream is determined by Dipeptidyl Peptidase IV, which cleaves 2 amino acids at the amino terminus of GIP, rendering it biologically inactive."
BMGC_PW1108,BMG_PW3546,,,"Semaphorin 4D (Sema 4D/CD100) is an axon guidance molecule with two disulfide-linked 150-kDa subunits. SEMA4D is structurally defined by a conserved 500-amino acid extracellular domain with 16 cysteines (sema domain) and also an Ig-like domain C-terminal to the sema domain. Sema4D is expressed on the cell surface as a homodimer; cysteine 679 within the sema domain is required for this dimerization. The main receptors for Sema4D are plexin-B1 and CD72. The activation of plexins by semaphorins initiates a variety of signaling processes that involve several small GTPases of the Ras and Rho families. Sema4D-Plexin-B1 interaction appears to mediate different and sometimes opposite effects depending on the cellular context. Plexin-B1 activation inhibits integrin-mediated cell attachment and cell migration through the activation of the R-RasGAP activity inherent to plexin-B1 or through the inhibition of RhoA. However, activation of plexin-B1 by Sema4D stimulates the migration of endothelial cells by mediating the activation of RhoA."
BMGC_PW1109,BMG_PW3549,,,"Sialic acids are a family of 9 carbon alpha-keto acids that are usually present in the non reducing terminal of glycoconjuates on the cell surface of eukaryotic cells. These sialylated conjugates play important roles in cell recognition and signaling, neuronal development, cancer metastasis and bacterial or viral infection. More than 50 forms of sialic acid are found in nature, the most abundant being N-acetylneuraminic acid (Neu5Ac, N-acetylneuraminate) (Li & Chen 2012, Wickramasinghe & Medrano 2011). The steps below describe the biosynthesis, transport, utilization and degradation of Neu5Ac in humans."
BMGC_PW1110,BMG_PW3553,,,"A number of so called non-canonical WNT ligands have been shown to promote intracellular calcium release upon FZD binding. This beta-catenin-independent WNT pathway acts through heterotrimeric G proteins and promotes calcium release through phophoinositol signaling and activation of phosphodiesterase (PDE). Downstream effectors include the calcium/calmodulin-dependent kinase II (CaMK2) and PKC (reviewed in De, 2011). The WNT Ca2+ pathway is important in dorsoventral polarity, convergent extension and organ formation in vertebrates and also has roles in negatively regulating 'canonical' beta-catenin-dependent transcription. Non-canonical WNT Ca2+ signaling is also implicated in inflammatory response and cancer (reviewed in Kohn and Moon, 2005; Sugimura and Li, 2010)."
BMGC_PW1111,BMG_PW3554,,,"The planar cell polarity (PCP) pathway controls the establishment of polarity within the plane of a sheet of cells. PCP was initially characterized in Drosophila, where it controls the arrangement of hair bristles and photoreceptors in the eye (reviewed in Maung and Jenny, 2011). In vertebrates, PCP regulates convergent extension (CE, a process by which a tissue narrows along one axis and lengthens along a perpendicular one), closure of the neural tube, hair orientation and inner ear development, among others (reviewed in Seifert and Mlodzik, 2007). Studies in Drosophila identified a core group of PCP genes including Frizzled (Fz), Flamingo (Fmi), Van Gogh (Vang), Dishevelled (Dsh), Prickle (Pk) and Diego (Dgo), whose products become asymmetrically localized in the cell upon initiation of PCP (reviewed Maung and Jenny, 2011). Subsequent studies in vertebrates have shown that many of these PCP genes are conserved. Unlike in Drosophila, where the upstream signal for the PCP pathway has not been defined, in vertebrates, a number of so-called 'non-canonical' WNTs have been shown to have roles in PCP processes. WNT5B and WNT11 are both required for CE during gastrulation, and WNT5A physically and genetically interacts with VANGL2 in the inner ear and the developing limb bud (Heisenberg et al, 2000; Rauch et al, 1997; Qian et al, 2007; Gao et al, 2011). WNT ligand can be bound by one of a number of FZD receptors or the single pass transmembrane proteins RYK or ROR, depending on context (reviewed in Green et al, 2008; Fradkin et al, 2010). Although the downstream pathway is not well established, vertebrate PCP signaling appears to work at least in part through DVL, DAAM1 and small GTPases to remodel the actin cytoskeleton (reviewed in Lai et al, 2009; Gao et al, 2012)."
BMGC_PW1112,BMG_PW3556,,,"The classic signalling route for G alpha (q) is activation of phospholipase C beta thereby triggering phosphoinositide hydrolysis, calcium mobilization and protein kinase C activation. This provides a path to calcium-regulated kinases and phosphatases, GEFs, MAP kinase cassettes and other proteins that mediate cellular responses ranging from granule secretion, integrin activation, and aggregation in platelets. Gq participates in many other signalling events including direct interaction with RhoGEFs that stimulate RhoA activity and inhibition of PI3K. Both in vitro and in vivo, the G-protein Gq seems to be the predominant mediator of the activation of platelets. Moreover, G alpha (q) can stimulate the activation of Burton tyrosine kinase (Ma Y C et al. 1998). Regulator of G-protein Signalling (RGS) proteins can regulate the activity of G alpha (z) (Soundararajan M et al. 2008)."
BMGC_PW1113,BMG_PW3557,,,"The G12/13 family is probably the least well characterized subtype, partly because G12/13 coupling is difficult to determine when compared with the other subtypes which predominantly rely on assay technologies that measure intracellular calcium. The G12/13 family are best known for their involvement in the processes of cell proliferation and morphology, such as stress fiber and focal adhesion formation. Interactions with Rho guanine nucleotide exchange factors (RhoGEFs) are thought to mediate many of these processes. (Buhl et al.1995, Sugimoto et al. 2003). Activation of Rho or the regulation of events through Rho is often taken as evidence of G12/13 signaling. Receptors that are coupled with G12/13 invariably couple with one or more other G protein subtypes, usually Gq."
BMGC_PW1114,BMG_PW3558,,,"Repulsive Sema4D-Plexin-B1 signaling involves four GTPases, Rnd1, R-Ras, Rho and Rac1. Sema4D-Plexin-B1 binding promotes Rnd1-dependent activation of the plexin-B1 GAP domain and transient suppression of R-Ras activity. R-Ras inactivation promotes PI3K and Akt inactivation followed by GSK-3beta activation and CRMP2 inactivation. Plexin-B1 also transiently associates with and activates p190Rho-GAP, triggering a transient decrease in activated Rho."
BMGC_PW1115,BMG_PW3559,,,"Sema4D-mediated attraction of endothelial cells requires Rho, but not R-Ras, signaling. Sema4D-mediated plexinB1 activation activates Rho and its downstream effector ROCK. ROCK then phosphorylates MLC to induce actomyosin stress fiber contraction and to direct the assembly of focal adhesion complexes and integrin-mediated adhesion."
BMGC_PW1116,BMG_PW3560,,,"There are eight classes of semaphorins and four types of plexins. Semaphorin (SEMA) classes 1 and 2 are found in invertebrates and classes 3-7 are vertebrate sempahorines. Sempahorin class 3 is secreted, whereas the other classes are synthesised as transmembrane proteins. Vertebrate plexins (PLXNs) are classified into four subfamilies plexin-A to -D. There are four A-type plexins, three B-type, one C-type and D-type. Interactions between different subfamilies of plexins and semaphorins show differential specificity, which trigger different sets of biological functions. Another level of functional specificity specificity is attained by plexins by coupling with various coreceptors expressed in a cell- or tissue-specific manner, such as neuropilins (NRP), L1CAM, c-MET proto-oncogene, ERB2, CD72 and CD45 (Kruger et al. 2005, Law & Lee 2012)."
BMGC_PW1117,BMG_PW3561,,,"Trafficking of GluR2-containing receptors is governed by protein protein interactions that are regulated by phosphorylation events. GluR2 binds NSF and AP2 in the proximal C terminal region and binds PICK and GRIP1/2 in the extreme C terminal region. GluR2 interaction with NSF is necessary to maintain the synaptic levels of GluR2-containing AMPA receptors both at basal levels and under conditions of synaptic activity. GluR2 interaction with GRIP helps anchor AMPA receptors at the synapse. Phosphorylation of GluR2 at S880 disrupts GRIP interaction but allows binding of PICK. PICK is activated by Ca sensitive Protein kinase C (PKC). Under basal conditions, in hippocampal synapse, GluR2-containing AMPA receptors (GluR2/GluR3) constitutively recycle between the synapse and the endosome by endocytosis and exocytosis. GRIP anchors the receptors at the synapse while PICK interaction internalizes the receptors and NSF helps maintain the synaptic receptors. Cerebellar stellate cells mainly contain GluR3 homomers as Ca permeable receptors. The interaction of GluR3 and GRIP is disrupted by PICK interaction by phosphorylation of equivalent of S880 residue in GluR3. Under conditions of repetitive presynaptic activity, there is PICK dependent removal of GluR2-lacking AMPA receptors and selective incorporation of GluR2-containing AMPA receptors at the synapse. The GluR2-containing AMPA receptors are first delivered to the surface by PICK and mobilized to the synapse by NSF dependent mechanism (Liu SJ and Cull-Candy SG Nat Neurosci. 2005 Jun;8(6):768-75)"
BMGC_PW1118,BMG_PW3562,,,"P2Y receptors are a family of purinergic receptors, G protein-coupled receptors stimulated by nucleotides such as ATP, ADP, UTP, UDP and UDP-glucose. To date, 12 P2Y receptors have been cloned in humans (Abbracchio MP et al, 2006; Fischer W and Krugel U, 2007). P2Y receptors are present in almost all human tissues where they exert various biological functions based on their G-protein coupling. Purine nucleotides are involved in a large number of intermediate metabolic pathways, taking part as substrates, products or allosteric factors."
BMGC_PW1119,BMG_PW3564,,,"Purinergic receptors (Burnstock G, 2006; Abbracchio MP et al, 2009) are a family of newly characterized plasma membrane molecules involved in several cellular functions such as vascular reactivity, apoptosis and cytokine secretion. The functions of these receptors are as yet only partially characterized. The family includes the GPCR P2Y purinergic receptors and adenosine P1 receptors. A third family member, the P2X receptor, is a ligand-gated ion channel."
BMGC_PW1120,BMG_PW3565,,,"Phospholipase C beta (PLCbeta) isoforms are activated by G-protein beta:gamma in the order PLCB3 > PLCB2 > PLCB1. Gbeta:gamma binds to the pleckstrin homology domain of PLC beta, increasing phospholipase activity and leading to increased hydrolysis of PIP2 to DAG and IP3."
BMGC_PW1121,BMG_PW3566,,,"Under normal conditions the vascular endothelium supports vasodilation, inhibits platelet adhesion and activation, suppresses coagulation, enhances fibrin cleavage and is anti-inflammatory in character. Under acute vascular trauma, vasoconstrictor mechanisms predominate and the endothelium becomes prothrombotic, procoagulatory and proinflammatory in nature. This is achieved by a reduction of endothelial dilating agents: adenosine, NO and prostacyclin; and by the direct action of ADP, serotonin and thromboxane on vascular smooth muscle cells to elicit their contraction (Becker et al. 2000). Cyclooxygenase-2 (COX-2) and endothelial nitric oxide synthase (eNOS) are primarily expressed in endothelial cells. Both are important regulators of vascular function. Under normal conditions, laminar flow induces vascular endothelial COX-2 expression and synthesis of Prostacyclin (PGI2) which in turn stimulates endothelial Nitric Oxide Synthase (eNOS) activity. PGI2 and NO both oppose platelet activation and aggregation, as does the CD39 ecto-ADPase, which decreases platelet activation and recruitment by metabolizing platelet-released ADP."
BMGC_PW1122,BMG_PW3567,,,"During steady state conditions, cytoplasmic [Ca2+] is reduced by the accumulation of Ca2+ in intracellular stores and Ca2+ extrusion."
BMGC_PW1123,BMG_PW3568,,,"Ca2+ homeostasis is controlled by processes that elevate or counter the elevation of cytosolic Ca2+. During steady state conditions, cytoplasmic Ca2+ is reduced by the accumulation of Ca2+ in intracellular stores and by Ca2+ extrusion. The primary intracellular calcium store in platelets is the dense tubular system, the equivalent of the ER system in other cell types. Ca2+ is extruded by Ca2+-ATPases including plasma membrane Ca2+ ATPases (PMCAs) and sarco/endoplasmic reticulum Ca2+ -ATPase isoforms (SERCAs). Activation of non- excitable cells involves the agonist-induced elevation of cytosolic Ca2+, an essential process for platelet activation. It occurs through Ca2+ release from intracellular stores and Ca2+ entry through the plasma membrane. Ca2+ store release involves phospholipase C (PLC)-mediated production of inositol-1,4,5-trisphosphate (IP3), which in turn stimulates IP3 receptor channels to release Ca2+ from intracellular stores. This is followed by Ca2+ entry into the cell through plasma membrane calcium channels, a process referred to as store-operated calcium entry (SOCE). Stromal interaction molecule 1 (STIM1), a Ca2+ sensor molecule in intracellular stores, and the four transmembrane channel protein Orai1 are the key players in platelet SOCE. Other major Ca2+ entry mechanisms are mediated by the direct receptor-operated calcium (ROC) channel, P2X1 and transient receptor potential channels (TRPCs)."
BMGC_PW1124,BMG_PW3569,,,"Cyclic guanosine monophosphate (cGMP) is an important secondary messenger synthesized by guanylate cyclases. cGMP has effects on phosphodiesterases (PDE), ion-gated channels, and the cGMP-dependent protein kinases (cGK, Protein Kinase G or PKG). It is involved in regulation of several physiological functions including vasodilation, platelet aggregation and neurotransmission. Elevation of intracellular cGMP activates PKG (Haslam et al. 1999) which regulates several intracellular molecules and pathways including the vasodilator-stimulated phosphoprotein (VASP) (Halbrugge et al. 1990) and the ERK pathway (Hood and Granger 1998, Li et al. 2001). cGMP mediates nitric oxide (NO)-induced vascular smooth muscle relaxation (Furchgott and Vanhoutte 1989). Phosphodiesterase 5 (PDE5) hydrolyzes cGMP; the PDE5 inhibitor sildenafil (Viagra) increases intracellular cGMP and thereby can be used as a treatment for erectile dysfunction (Corbin and Francis 1999). The role of the cGMP and PKG in platelet activation was controversial as increases in platelet cGMP levels were observed in response to both platelet agonists (thrombin, ADP or collagen) and inhibitors (NO donors such as sodium nitroprusside), but it is currently accepted that PKG inhibits platelet activation (Haslam et al. 1999). Consistent with this, nitric oxide (NO) donors that inhibit platelet activation enhance intracellular cGMP (Haslam et al. 1999). cGMP also plays an important stimulatory role in GPIb-IX-mediated platelet activation. Platelet responses to cGMP have been proposed to be biphasic, consisting of an early stimulatory response that promotes platelet activation followed by a delayed platelet inhibition that serves to limit the size of platelet aggregates (Li et al 2003)."
BMGC_PW1125,BMG_PW3570,,,"The general function of the G alpha (s) subunit (Gs) is to activate adenylate cyclase (Tesmer et al. 1997), which in turn produces cAMP, leading to the activation of cAMP-dependent protein kinases (often referred to collectively as Protein Kinase A). The signal from the ligand-stimulated GPCR is amplified because the receptor can activate several Gs heterotrimers before it is inactivated. Another downstream effector of G alpha (s) is the protein tyrosine kinase c-Src (Ma et al. 2000)."
BMGC_PW1126,BMG_PW3571,,,"Co-activation of P2Y1 and P2Y12 is necessary for complete platelet activation. P2Y1 is coupled to Gq and helps trigger the release of calcium from internal stores, leading to weak and reversible platelet aggregation. P2Y12 is Gi coupled, inhibiting adenylate cyclase, leading to decreased cAMP, a consequent decrease in cAMP-dependent protein kinase activity which increases cytoplasmic [Ca2+], necessary for activation (Woulfe et al. 2001). In activated platelets, P2Y12 signaling is required for the amplification of aggregation induced by all platelet agonists including collagen, thrombin, thromboxane, adrenaline and serotonin. P2Y12 activation causes potentiation of thromboxane generation, secretion leading to irreversible platelet aggregation and thrombus stabilization."
BMGC_PW1127,BMG_PW3572,,,The classical signalling mechanism for G alpha (i) is inhibition of the cAMP dependent pathway through inhibition of adenylate cyclase (Dessauer C W et al. 2002). Decreased production of cAMP from ATP results in decreased activity of cAMP-dependent protein kinases. Other functions of G alpha (i) includes activation of the protein tyrosine kinase c-Src (Ma Y C et al. 2000). Regulator of G-protein Signalling (RGS) proteins can regulate the activity of G alpha (i) (Soundararajan et al. 2008).
BMGC_PW1128,BMG_PW3573,,,"The heterotrimeric G protein G alpha (z), is a member of the G (i) family. Unlike other G alpha (i) family members it lacks an ADP ribosylation site cysteine four residues from the carboxyl terminus and is thus pertussis toxin-insensitive. It inhibits adenylyl cyclase types I, V and VI (Wong Y H et al. 1992). G alpha (z) interacts with the Rap1 GTPase activating protein (Rap1GAP) to attenuate Rap1 signaling. Like all G-proteins G alpha (z) has an intrinsic GTPase activity, but this activity tends to be lower for the pertussis toxin insensitive G-proteins, most strikingly so for G alpha (z), whose kcat value for GTP hydrolysis is 200-fold lower than those of G alpha (s) or G alpha (i) (Grazziano et al. 1989). G alpha (z) knockout mice have disrupted platelet aggregation at physiological concentrations of epinephrine and responses to several neuroactive drugs are altered (Yang et al. 2000). Regulator of G-protein Signalling (RGS) proteins can regulate the activity of G alpha (z) (Soundararajan M et al. 2008)."
BMGC_PW1129,BMG_PW3574,,,The DCC family includes DCC and neogenin in vertebrates. DCC is required for netrin-induced axon attraction. DCC is a transmembrane protein lacking any identifiable catalytic activity. Protein tyrosine kinase 2/FAK and src family kinases bind constitutively to the cytoplasmic domain of DCC and their activation couples to downstream intracellular signaling complex that directs the organization of actin.
BMGC_PW1130,BMG_PW3575,,,"Unc5 netrin receptors mediate repellent responses to netrin. Four Unc5 members have been found in humans: Unc5A, B, C and D. Different studies have suggested that long-range repulsion to netrin requires the cooperation of Unc5 and DCC, but that Unc5 without DCC is sufficient for short-range repulsion. The binding of netrin to Unc5 triggers the phosphorylation of Unc5 in its ZU-5 domain. Several proteins have been proposed to interact with Unc5 family members in mediating a repellent response, including tyrosine phosphatase Shp2, the F-actin anti-capping protein Mena, and ankyrin."
BMGC_PW1131,BMG_PW3576,,,"In the presence of Netrin1, DCC and UNC5 generate attractive and repulsive signals to growing axons. In the absence of Netrin-1, DCC induces cell death signaling initiated via caspase cleavage of DCC and the interaction of caspase-9. Recent reports have shown that UNC5 receptors similarly induce apoptosis in the absence of Netrin-1. These reactions proceed without a requirement for cytochrome c release from mitochondria or interaction with apoptotic protease activating factor 1 (APAF1). DCC thus regulates an apoptosome-independent pathway for caspase activation. DCC and UNC-5 are hence defined as dependence receptors. Dependence receptors exhibit dual functions depending on the availability of ligand. They create cellular states of dependence on their respective ligands by either inducing apoptosis when unoccupied by the ligand, or inhibiting apoptosis in the presence of the ligand."
BMGC_PW1132,BMG_PW3577,,,"The levels of second messengers such as Ca+2, cAMP and cGMP may regulate the response of the growth cone to a particular cue. Netrin-1 as a guidance molecule depends on intracellular Ca+2 concentration, coactivation of PI3K and PLCgamma, and the type of response depends on the levels of cAMP. Netrin first stimulates its receptor DCC, resulting in the activation of the enzyme phospholipase C. This then produces the messenger molecules, inositol-1,4,5-trisphosphate (IP3) and DAG, which in turn causes the release of Ca+2 from intracellular stores. Ca+2 release from the stores then activates TRPC channels on the cell surface. DAG activates TRPC3 and TRPC6 in a direct, membrane delimited manner, and IP3 may activate TRPC channels by depleting the ER Ca+2 levels."
BMGC_PW1133,BMG_PW3578,,"Cell-cell adherens junctions (AJs), the most common type of intercellular adhesions, are important for maintaining tissue architecture and cell polarity and can limit cell movement and proliferation. At AJs, E-cadherin serves as an essential cell adhesion molecules (CAMs). The cytoplasmic tail binds beta-catenin, which in turn binds alpha-catenin. Alpha-catenin is associated with F-actin bundles directly and indirectly. The integrity of the cadherin-catenin complex is negatively regulated by phosphorylation of beta-catenin by receptor tyrosine kinases (RTKs) and cytoplasmic tyrosine kinases (Fer, Fyn, Yes, and Src), which leads to dissociation of the cadherin-catenin complex. Integrity of this complex is positively regulated by beta -catenin phosphorylation by casein kinase II, and dephosphorylation by protein tyrosine phosphatases. Changes in the phosphorylation state of beta-catenin affect cell-cell adhesion, cell migration and the level of signaling beta-catenin. Wnt signaling acts as a positive regulator of beta-catenin by inhibiting beta-catenin degradation, which stabilizes beta-catenin, and causes its accumulation. Cadherin may acts as a negative regulator of signaling beta-catenin as it binds beta-catenin at the cell surface and thereby sequesters it from the nucleus. Nectins also function as CAMs at AJs, but are more highly concentrated at AJs than E-cadherin. Nectins transduce signals through Cdc42 and Rac, which reorganize the actin cytoskeleton, regulate the formation of AJs, and strengthen cell-cell adhesion.","The adherens junctions (AJ) are multiprotein complexes that promote homotypic cell adhesion in nearly all types of tissue by linking membrane and cytoskeletal components at discrete contact regions (reviewed in Hartsock & Nelson 2008; Gumbiner 2005; Ebnet, 2008). The molecular constituents of adherens junctions form adhesive units which are organized into higher order junctional adhesions that create a zipper-like seal between adjacent cells. Junctional adhesions function in epithelial cell polarization and in the coupling of cytoskeletons in adjacent cells that allow coordinated movements. During embryonic development, AJs function in specifying adhesion between cells and contribute in the sorting of different cell types. AJs also regulate cell polarity and shape, promote cell-cell communication and help mediate contact inhibition of cell growth. This module covers transdimerization events involving AJ transmembrane proteins (cadherins and nectins) (Gumbiner 2005; Ebnet 2008; Hartsock & Nelson 2008)."
BMGC_PW1134,BMG_PW3579,,,"The neural cell adhesion molecule, NCAM1 is generally considered as a cell adhesion mediator, but it is also considered to be a signal transducing receptor molecule. NCAM1 is involved in multiple cis- and trans-homophilic interactions. It is also involved in several heterophilic interactions with a broad range of other molecules, thereby modulating diverse biological phenomena including cellular adhesion, migration, proliferation, differentiation, survival and synaptic plasticity."
BMGC_PW1135,BMG_PW3580,,,"The Lysophospholipid receptor (LPLR) group are members of the G protein-coupled receptor family of integral membrane proteins that are important for lipid signaling. In humans there are eight LPL receptors, each encoded by a separate gene (these genes also sometimes referred to as ""Edg"" or endothelial differentiation gene). The ligands for LPLRs are the lysophospholipid extracellular signaling molecules, lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P). The primary effects are inhibition of adenylyl cyclase and release of calcium from the endoplasmic reticulum, as well as secondary effects of preventing apoptosis and increasing cell proliferation (Contos JJ et al, 2000; An S et al, 1998; Fukushima N and Chun J, 2001)."
BMGC_PW1136,BMG_PW3581,,,"Opsins are light-sensitive, 35-55 kDa membrane-bound G protein-coupled receptors of the retinylidene protein family found in photoreceptor cells of the retina. Five classical groups of opsins are involved in vision, mediating the conversion of a photon of light into an electrochemical signal, the first step in the visual transduction cascade (Terakita A, 2005; Nickle B and Robinson PR, 2007). Another opsin found in the mammalian retina, melanopsin, is involved in circadian rhythms and pupillary reflex but not in image-forming (Hankins MW et al, 2008; Kumbalasiri T and Provencio I, 2005). Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G protein transducin, encoded by GNAT genes, is one of the transducers of a visual impulse that performs the coupling between rhodopsin and cGMP-phosphodiesterase. Defects in GNAT1 are the cause of congenital stationary night blindness autosomal dominant type 3, also known as congenital stationary night blindness Nougaret type. Congenital stationary night blindness is a non-progressive retinal disorder characterized by impaired night vision (Dryja TP et al, 1996). Defects in GNAT2 are the cause of achromatopsia type 4 (ACHM4). Achromatopsia is an autosomal recessively inherited visual disorder that is present from birth and that features the absence of color discrimination (Kohl S et al, 2002)."
BMGC_PW1137,BMG_PW3582,,,"The calcitonin peptide family comprises calcitonin, amylin, calcitonin gene-related peptide (CGRP), adrenomedullin (AM) and intermedin (AM2). Calcitonin is a 32 amino acid peptide, involved in bone homeostasis (Sexton PM et al, 1999). Amylin is a product of the islet beta-cell (Cooper GJ et al, 1987), along with insulin and probably has a hormonal role in the regulation of nutrient intake (Young A and Denaro M, 1998). Adrenomedullin (AM) is a ubiquitously expressed peptide initially isolated from phaechromocytoma (a tumour of the adrenal medulla) (Kitamura K et al, 1993). Both AM and AM2 (Takei Y et al, 2004) belong to a family of calcitonin-related peptide hormones important for regulating diverse physiologic functions and the chemical composition of fluids and tissues. The receptor family for these peptides consists of two class B GPCRs, the calcitonin receptor (CT) and calcitonin receptor-like receptor (CL) (Poyner DR er al, 2002). Whilst the receptor for calcitonin is a conventional class B GPCR, the receptors for CGRP, AM and amylin require additional proteins, called the receptor activity modifying proteins (RAMPs). There are three RAMPs in mammals; they interact with the CT receptor to convert it to receptors for amylin. For CGRP and AM, the related CL interacts with RAMP1 to give a CGRP receptor and RAMP2 or 3 to give AM receptors. CL by itself will bind no known endogenous ligand."
BMGC_PW1138,BMG_PW3583,,"Tight junctions (TJs) are essential for establishing a selectively permeable barrier to diffusion through the paracellular space between neighboring cells. TJs are composed of at least three types of transmembrane protein -occludin, claudin and junctional adhesion molecules (JAMs)- and a cytoplasmic 'plaque' consisting of many different proteins that form large complexes. These are proposed to be involved in junction assembly, barrier regulation, cell polarity, gene transcription, and other pathways.","Tight junctions (TJs) are the most apical component of the epithelial junctional complex forming a belt-like structure at the cellular junction. When visualized by freeze-fracture electron microscopy they appear as a branched network of intramembrane strands that correspond to the sites of direct membrane contacts and that are composed of the integral membrane claudin proteins. The TJs act as a primary barrier to the diffusion of solutes through the paracellular space (barrier function) (Tsukita et al., 2001). They also prevent the intermixing of intramembrane proteins and lipids and thus create a boundary between the apical and the basolateral membrane domains of polarized epithelial cells (fence function) (Tsukita et al., 2001). Interestingly, the fence function seems not to depend on TJ strands (Umeda et al., 2006). Recents evidence indicates that the TJs also participate in signal transduction mechanisms which regulate cell proliferation and morphogenesis (Matter and Balda, 2003; Matter and Balda, 2007). This module describes the major molecular interactions responsible for the formation of TJ strands and for the rectruitment of the PAR-3-PKC-PAR-6 and CRB3-Pals1-PATJ complexes that function in tight junction formation (Ebnet, 2008)."
BMGC_PW1139,BMG_PW3584,,,"The glucagon hormone family regulates the activity of GPCRs from the secretin receptor subfamily in Class II/B (Mayo KE et al, 2003)."
BMGC_PW1140,BMG_PW3585,,,"Nectins and Nectin-like molecules (Necls) also undergo trans-heterophilic interactions to interact with other nectin or Necl family members. Besides these trans interactions among nectins and nectin-like family members, trans-homophilic interactions have also been described between nectins or Necls with other immunoglobulin-superfamily members like CD96, CD226 and CRTAM (Sakisaka et al., 2007; Takai et al., 2008). It should be noted that some of these interactions might not exist in epithelial cell-cell contacts but may occur in other cell-cell adhesion systems."
BMGC_PW1141,BMG_PW3586,,,"Epithelial cell-cell contacts consist of three major adhesion systems: adherens junctions (AJs), tight junctions (TJs), and desmosomes. These adhesion systems differ in their function and composition. AJs play a critical role in initiating cell-cell contacts and promoting the maturation and maintenance of the contacts (reviewed in Ebnet, 2008; Hartsock and Nelson, 2008). TJs form physical barriers in various tissues and regulate paracellular transport of water, ions, and small water soluble molecules (reviewed in Rudini and Dejana, 2008; Ebnet, 2008; Aijaz et al., 2006; Furuse and Tsukit, 2006). Desmosomes mediate strong cell adhesion linking the intermediate filament cytoskeletons between cells and playing roles in wound repair, tissue morphogenesis, and cell signaling (reviewed in Holthofer et al., 2007)."
BMGC_PW1142,BMG_PW3587,,,"Ghrelin is a peptide hormone of 28 amino acid residues which is acylated at the serine-3 of the mature peptide. Ghrelin is synthesized in several tissues: X/A-like cells of the gastric mucosa (the major source of ghrelin), hypothalamus, pituitary, adrenal gland, thyroid, breast, ovary, placenta, fallopian tube, testis, prostate, liver, gall bladder, pancreas, fat tissue, human lymphocytes, spleen, kidney, lung, skeletal muscle, myocardium, vein and skin. Ghrelin binds the GHS-R1a receptor present in hypothalamus pituitary, and other tissues. Binding causes appetite stimulation and release of growth hormone. Levels of circulating ghrelin rise during fasting, peak before a meal, and fall according to the calories ingested. Preproghrelin is cleaved to yield proghrelin which is then acylated by ghrelin O-acyltransferase to yield octanoyl ghrelin and decanoyl ghrelin. Only octanoyl ghrelin is able to bind and activate the GHS-R1a receptor. Unacylated ghrelin (des-acyl ghrelin) is also present in plasma but its function is controversial. Acyl proghrelin is cleaved by prohormone convertase 1/3 to yield the mature acyl ghrelin and C-ghrelin. Secretion of ghrelin is inhibited by insulin, growth hormone (somatotropin), leptin, glucose, glucagon, and fatty acids. Secretion is stimulated by insulin-like growth factor-1 and muscarinic agonists. In the bloodstream acyl ghrelin is deacylated by butyrylcholinesterase and platelet-activating factor acetylhydrolase. Other enzymes may also deacylate acyl ghrelin."
BMGC_PW1143,BMG_PW3588,,"Axon guidance represents a key stage in the formation of neuronal network. Axons are guided by a variety of guidance factors, such as netrins, ephrins, Slits, and semaphorins. These guidance cues are read by growth cone receptors, and signal transduction pathways downstream of these receptors converge onto the Rho GTPases to elicit changes in cytoskeletal organization that determine which way the growth cone will turn.","Axon guidance / axon pathfinding is the process by which neurons send out axons to reach the correct targets. Growing axons have a highly motile structure at the growing tip called the growth cone, which senses the guidance cues in the environment through guidance cue receptors and responds by undergoing cytoskeletal changes that determine the direction of axon growth. Guidance cues present in the surrounding environment provide the necessary directional information for the trip. These extrinsic cues have been divided into attractive or repulsive signals that tell the growth cone where and where not to grow. Genetic and biochemical studies have led to the identification of highly conserved families of guidance molecules and their receptors that guide axons. These include netrins, Slits, semaphorins, and ephrins, and their cognate receptors, DCC and or uncoordinated-5 (UNC5), roundabouts (Robo), neuropilin and Eph. In addition, many other classes of adhesion molecules are also used by growth cones to navigate properly which include NCAM and L1CAM. For review of axon guidance, please refer to Russel and Bashaw 2018, Chedotal 2019, Suter and Jaworski 2019). Axon guidance cues and their receptors are implicated in cancer progression (Biankin et al. 2012), where they likely contribute to cell migration and angiogenesis (reviewed by Mehlen et al. 2011)."
BMGC_PW1144,BMG_PW3589,,,"SLC transporters described in this section transport bile salts, organic acids, metal ions and amine compounds. Myo-Inositol is a neutral cyclic polyol, abundant in mammalian tissues. It is a precursor to phosphatidylinositols (PtdIns) and to the inositol phosphates (IP), which serve as second messengers and also act as key regulators of many cell functions. Three members of the glucose transporter gene family encode inositol transporters (SLC2A13, SLC5A3 and SLC5A11) (Schneider 2015). Five human SLC13 genes encode sodium-coupled sulphate, di- and tri-carboxylate transporters typically located on the plasma membrane of mammalian cells (Pajor 2006). The SLC16A gene family encode proton-linked monocarboxylate transporters (MCT) which mediate the transport of monocarboxylates such as lactate and pyruvate, major energy sources for all cells in the body so their transport in and out of cells is crucial for cellular function (Morris & Felmlee 2008). The transport of essential metals and other nutrients across tight membrane barriers such as the gastrointestinal tract and blood-brain barrier is mediated by metal-transporting proteins (encoded by SLC11, SLC30, SLC31, SLC39, SLC40 and SLC41). They can also regulate metals by efflux out of cells and cellular compartments to avoid toxic build-up (Bressler et al. 2007). The SLC6 gene family encodes proteins that mediate neurotransmitter uptake in the central nervous system (CSN) and peripheral nervous system (PNS), thus terminating a synaptic signal. The proteins mediate transport of GABA (gamma-aminobutyric acid), norepinephrine, dopamine, serotonin, glycine, taurine, L-proline, creatine and betaine (Chen et al. 2004). Carrier-mediated urea transport allows rapid urea movement across the cell membrane, which is particularly important in the process of urinary concentration and for rapid urea equilibrium in non-renal tissues. Two carriers exist in humans, encoded by SLC14A1 and ALC14A2 (Olives et al. 1994). Choline uptake is the rate-limiting step in the synthesis of the neurotransmitter acetylcholine. SLC genes SLC5A7 and the SLC44 family encode choline transporters ((Okuda & Haga 2000, Traiffort et al. 2005). The SLC22 gene family of solute carriers function as organic cation transporters (OCTs), cation/zwitterion transporters (OCTNs) and organic anion transporters (OATs). Most of this family are polyspecific transporters. Since many of these transporters are expressed in the liver, kidney and intestine, they play an important role in drug absorption and excretion. Substrates include xenobiotics, drugs, and endogenous amine compounds (Koepsell & Endou 2004)."
BMGC_PW1145,BMG_PW3590,,,"Respiratory oxidation in the mitochondria produces carbon dioxide (CO2) as a waste product. CO2 is in equilibrium with bicarbonate (HCO3-) and is the body's central pH buffering system. HCO3- is charged so cannot move across membranes unaided. The bicarbonate transport proteins move bicarbonate across the membrane. There are 14 genes which encode these transport proteins in mammals. Applying the Human Genome Organization's sytematic nomenclature to human genes, the bicarbonate transporters belong to the SLC4A and SLC26A families. Within SLC4A, there are two distinct subfamilies, functionally corresponding to the electroneutral Cl-/HCO3- exchangers and Na+-coupled HCO3- co-transporters (Romero MF et al, 2004; Cordat E and Casey JR, 2009)."
BMGC_PW1146,BMG_PW3591,,,"Teleologically, one might argue that inorganic cation and anion transport would be evolutionarily among the oldest transport functions. Eight families comprise the group that transports exclusively inorganic cations and anions across membranes : SLC4 plays a pivotal role in mediating Na+ - and/or Cl- -dependent transport of basic anions [e.g. HCO3-, (CO3)2-] in various tissues and cell types (in addition to pH regulation, specific members of this family also contribute to vectorial trans-epithelial base transport in several organ systems including the kidney, pancreas, and eye) (Pushkin A and Kurtz I, 2006); SLC8 is a group of Na+/Ca2+ exchangers (SLC8A1 is involved in cardiac contractility) (Quednau BD et al, 2004); SLC24 is a group of Na+/Ca2+ or Na+/K+ exchangers (Altimimi HF and Schnetkamp PP, 2007); SLC9 comprises Na+/H+ exchanger proteins involved in the electroneutral exchange of sodium ion and protons (Orlowski J and Grinstein S, 2004); SLC12 functions as Na+, K+ and Cl- ion electroneutral symporters (Hebert SC et al, 2004); SLC26 is the trans-epithelial multifunctional anion (e.g. sulfate, oxalate, HCO-, Cl-) exchanger family, important in cartilage development, production of thyroid hormone, sound amplification in the cochlea etc (Sindic A et al, 2007; Dorwart MR et al, 2008; Ashmore J, 2008). SLC34 is an important Type II Na+/(HPO4)2- symporter (Forster IC et al, 2006; Virkki LV et al, 2007); SLC20 was originally identified as a viral receptor, and functions as a Type III Na+/(H2PO4)- symporter (Collins JF et al, 2004; Virkki LV et al, 2007). Eight SLC gene families are involved in the transport of amino acids and oligopeptides."
BMGC_PW1147,BMG_PW3592,,,"This section groups the processes mediated by SLC transporters, by which vitamins and cofactors, as well as nucleosides, nucleotides, nucleobases, and related molecules cross lipid bilayer membranes (He et al. 2009). The human SLC5A6 encodes the Na+-dependent multivitamin transporter SMVT (Prasad et al. 1999). SMVT co-transports biotin (vitamin B7), D-Pantothoate (vitamin B5) and lipoic acid into cells with Na+ ions electrogenically. Four SLC gene families encode transporters that mediate the movement of nucleosides and free purine and pyrimidine bases across the plasma membrane. These transporters play key roles in nucleoside and nucleobase uptake for salvage pathways of nucleotide synthesis, and in the cellular uptake of nucleoside analogues used in the treatment of cancers and viral diseases (He et al. 2009). The human gene SLC33A1 encodes acetyl-CoA transporter AT1 (Kanamori et al. 1997). Acetyl-CoA is transported to the lumen of the Golgi apparatus, where it serves as the substrate of acetyltransferases that O-acetylates sialyl residues of gangliosides and glycoproteins. Nucleotide sugars are used as sugar donors by glycosyltransferases to create the sugar chains for glycoconjugates such as glycoproteins, polysaccharides and glycolipids. Glycosyltransferases reside mainly in the lumen of the Golgi apparatus and endoplasmic reticulum (ER) whereas nucleotide sugars are synthesized in the cytosol. The human solute carrier family SLC35 encode nucleotide sugar transporters (NSTs), localised on Golgi and ER membranes, which can mediate the antiport of nucleotide sugars in exchange for the corresponding nucleoside monophosphates (eg. UMP for UDP-sugars) (Handford et al. 2006). Long chain fatty acids (LCFAs) can be used for energy sources and steroid hormone synthesis and regulate many cellular processes such as inflammation, blood pressure, the clotting process, blood lipid levels and the immune response. The SLC27A family encode fatty acid transporter proteins (FATPs) (Stahl 2004). The SLC gene family members SLCO1 SLCO2 and SLCO3 encode organic anion transporting polypeptides (OATPs). OATPs are membrane transport proteins that mediate the sodium-independent transport of a wide range of amphipathic organic compounds including bile salts, steroid conjugates, thyroid hormones, anionic oligopeptides and numerous drugs (Hagenbuch & Meier 2004)."
BMGC_PW1148,BMG_PW3593,,,"Proteins with transporting functions can be roughly classified into 3 categories: ATP-powered pumps, ion channels, and transporters. Pumps utilize the energy released by ATP hydrolysis to power the movement of the substrates across the membrane, against their electrochemical gradient. Channels at the open state can transfer the substrates (ions or water) down their electrochemical gradient, at an extremely high efficiency (up to 108 s-1). Transporters facilitate the movement of a specific substrate either against or following their concentration gradient, at a lower speed (about 102 -104 s-1); as generally believed, conformational change of the transporter protein is involved in the transfer process. According to the Human Genome Organization (HUGO) Gene Nomenclature Committee, all human transporters can be grouped into the solute-carrier (SLC) superfamily (http://www.genenames.org/genefamilies/SLC). Currently, there are 55 SLC families in the superfamily, with a total of at least 362 putatively functional protein-coding genes (Hediger et al. 2004, He et al. 2009; http://www.bioparadigms.org/slc/intro.htm). At least 20-25% amino-acid sequence identity is shared by members belonging to the same SLC family. No homology is shared between different SLC families. While the HUGO nomenclature system by definition only includes human genes, the nomenclature system has been informally extended to include rodent species through the use of lower cases letters (e.g., Slc1a1 denotes the rodent ortholog of the human SLC1A1 gene). And it's worthwhile to mention that pumps, channels and aquaporins are not included in SLC superfamily. To date, nine SLC gene families (SLC4, SLC5, SLC8, SLC9, SLC12, SLC20, SLC24, SLC26 and SLC34) comprise the group that exclusively transports inorganic cations and anions across membranes. A further eight SLC gene families (SLC1, SLC6, SLC7, SLC16, SLC25, SLC36, SLC38 and SLC43) are involved in the transport of amino acids and oligopeptides (He et al. 2009). Two gene families are responsible for glucose transport in humans. SLC2 (encoding GLUTs) and SLC5 (encoding SGLTs) families mediate glucose absorption in the small intestine, glucose reabsorption in the kidney, glucose uptake by the brain across the blood-brain barrier and glucose release by all cells in the body (Wood & Trayhurn 2003). SLC transporters are able to transport bile salts, organic acids, metal ions and amine compounds. Myo-Inositol is a precursor to phosphatidylinositols (PtdIns) and to the inositol phosphates (IP), which serve as second messengers and also act as key regulators of many cell functions (Schneider 2015). Mono-, di- and tri-carboxylate transporters mediate the transport of these acids across cellular membranes (Pajor 2006, Morris & Felmlee 2008). Essential metals are transported by metal-transporting proteins, which also control their efflux to avoid toxic build-up (Bressler et al. 2007). The SLC6 gene family encodes proteins that mediate neurotransmitter uptake in the central nervous system (CSN) and peripheral nervous system (PNS), thus terminating a synaptic signal (Chen et al. 2004). Urea transport is particularly important in the process of urinary concentration and for rapid urea equilibrium in non-renal tissues (Olives et al. 1994). Choline uptake is the rate-limiting step in the synthesis of the neurotransmitter acetylcholine. SLC genes SLC5A7 and the SLC44 family encode choline transporters (Traiffort et al. 2005). The SLC22 gene family of solute carriers function as organic cation transporters (OCTs), cation/zwitterion transporters (OCTNs) and organic anion transporters (OATs). They play important roles in drug absorption and excretion. Substrates include xenobiotics, drugs, and endogenous amine compounds (Koepsell & Endou 2004). The human SLC5A6 encodes the Na+-dependent multivitamin transporter SMVT (Prasad et al. 1999). SMVT co-transports biotin (vitamin B7), D-Pantothoate (vitamin B5) and lipoic acid into cells with Na+ ions electrogenically. Four SLC gene families encode transporters that play key roles in nucleoside and nucleobase uptake for salvage pathways of nucleotide synthesis, and in the cellular uptake of nucleoside analogues used in the treatment of cancers and viral diseases (He et al. 2009). The human gene SLC33A1 encodes acetyl-CoA transporter AT1 (Kanamori et al. 1997). Acetyl-CoA is transported to the lumen of the Golgi apparatus, where it serves as the substrate of acetyltransferases that O-acetylates sialyl residues of gangliosides and glycoproteins. Nucleotide sugars are used as sugar donors by glycosyltransferases to create the sugar chains for glycoconjugates such as glycoproteins, polysaccharides and glycolipids. The human solute carrier family SLC35 encode nucleotide sugar transporters (NSTs), localised on Golgi and ER membranes, which can mediate the antiport of nucleotide sugars in exchange for the corresponding nucleoside monophosphates (eg. UMP for UDP-sugars) (Handford et al. 2006). Long chain fatty acids (LCFAs) can be used for energy sources and steroid hormone synthesis and regulate many cellular processes such as inflammation, blood pressure, the clotting process, blood lipid levels and the immune response. The SLC27A family encode fatty acid transporter proteins (FATPs) (Anderson & Stahl 2013). The SLC gene family members SLCO1 SLCO2 and SLCO3 encode organic anion transporting polypeptides (OATPs). OATPs are membrane transport proteins that mediate the sodium-independent transport of a wide range of amphipathic organic compounds including bile salts, steroid conjugates, thyroid hormones, anionic oligopeptides and numerous drugs (Hagenbuch & Meier 2004)."
BMGC_PW1149,BMG_PW3594,,,"Six SLC gene families encode proteins which mediate transport of metals. The families are SLC11, SLC30, SLC31, SLC39, SLC40 and SLC41 (He L et al, 2009; Bressler JP et al, 2007)."
BMGC_PW1150,BMG_PW3595,,,"Calcium ions are used by cells as ubiquitous signalling molecules that control diverse physiological events. Three mammalian gene families control Ca2+ transport across plasma membranes and intracellular compartments (Lytton J, 2007). They are the Na+/Ca2+ exchanger family designated NCX (SLC8) (three members NCX1-3) (Quednau BD et al, 2004), the Na+/Ca2+-K+ exchanger family designated NCKX (SLC24) (five members NCKX1-5) (Schnetkamp PP, 2004) and a Ca2+/cation exchanger (NCKX6, NCLX) whose physiological function remains unclear."
BMGC_PW1151,BMG_PW3596,,,"The SLC9 gene family encode proteins (sodium/proton exchangers, NHE or NHX) which exchange sodium (influx) for protons (efflux) electroneutrally. This mechanism is important because many metabolic processes generate acids which need to be removed to maintain pH. This is the major proton extruding system in cells, driven by the inward sodium ion chemical gradient. To date, there are eleven NHE genes, NHE1-11. NHE1-5 exchange cations at the cell membrane. NHE6-9 exchange cations at endosomal membranes or the trans-golgi network membranes."
BMGC_PW1152,BMG_PW3597,,,"Diacylglycerol (DAG) is an important source of arachidonic acid, a signalling molecule and the precursor of the prostaglandins. In human platelet almost all the DAG produced from phosphatidylinositol degradation contains arachidonate (Takamura et al. 1987). DAG is hydrolysed by DAG lipase to 2-arachidonylglycerol (2-AG) which is further hydrolysed by monoacylglycerol lipase. 2-AG is an agonist of cannabinoid receptor 1."
BMGC_PW1153,BMG_PW3598,,,"The cation-chloride cotransporter family (SLC12 gene family) are membrane proteins that cotranslocate chloride (Cl-) with either Na+, K+, or both cations electroneutrally. The general topology of these proteins feature 12 transmembrane domains flanked by hydrophilic NH2 and COOH-terminal domains. They are secondary transporters and movement of these cations is determined by gradients established by primary transporters such as Na+-K+-ATPase. Cotransporters that use Na+ as the driving force move Cl- into the cell because Na+ concentration is higher in the extracellular region. Conversely, cotransporters that use K+ as the driving force move Cl- out of the cell because K+ concentration is higher inside the cell. The SLC12 gene family contains nine members, of which seven are clearly characterized genes and two are orphans. They encode cotransporter proteins which are 1) involved in Cl- homeostasis, 2) regulate cell volume, 3) involved in transepithelial ion movement (salt reabsorption in the kidney) and 4) involved in response to neurotransmitters such as GABA. Three different cotransporter subtypes are expressed by the seven characterized genes; one thiazide-sensitive Na+/Cl- cotransporter, two loop diuretic-sensitive Na+, K+/2Cl- cotransporters and four K+/Cl- cotransporters (Gamba G, 2005; Hebert SC et al, 2004)."
BMGC_PW1154,BMG_PW3599,,,"Small interfering RNAs (siRNAs) are 21-25 nucleotide single-stranded RNAs produced by cleavage of longer double-stranded RNAs by the enzyme DICER1 within the RISC loading complex containing DICER1, an Argonaute protein, and either TARBP2 or PRKRA (PACT). Typically the long double-stranded substrates originate from viruses or repetitive elements in the genome and the two strands of the substrate are exactly complementary. After cleavage by DICER1 the 21-25 nucleotide double-stranded product is loaded into an Argonuate protein (humans contain 4 Argonautes) and rendered single-stranded by a mechanism that is not well characterized. siRNA-loaded AGO2 is predominantly located at the cytosolic face of the rough endoplasmic reticulum and has also been observed in the nucleus."
BMGC_PW1155,BMG_PW3600,,,"Small RNAs act with components of the RNA-induced silencing complex (RISC) to post-transcriptionally repress expression of mRNAs (reviewed in Nowotny and Yang 2009, Chua et al. 2009). Two mechanisms exist: 1) cleavage of target RNAs by complexes containing Argonaute2 (AGO2, EIF2C2) and a guide RNA that exactly matches the target mRNA and 2) inhibition of translation of target RNAs by complexes containing AGO2 and an inexactly matching guide RNA or by complexes containing a nonendonucleolytic Argonaute (AGO1 (EIF2C1), AGO3 (EIF2C3), or AGO4 (EIF2C4)) and a guide RNA of exact or inexact match. Small interfering RNAs (siRNAs) and microRNAs (miRNAs) can serve as guide RNAs in both types of mechanism. RNAi also appears to direct chromatin modifications that cause transcriptional gene silencing (reviewed in Verdel et al. 2009)."
BMGC_PW1156,BMG_PW3601,,,"Expression of rRNA genes is coupled to the overall metabolism of the cell by the NAD-dependent histone deacetylase SIRT1, a component of the Energy-dependent Nucleolar Silencing Complex (eNoSC) (Murayama et al. 2008, reviewed in Salminen and Kaarniranta 2009, Grummt and Voit 2010). eNoSC comprises Nucleomethylin (NML), SIRT1, and the histone methylase SUV39H1 (Murayama et al. 2008). Deacetylation and methylation of histone H3 in the chromatin of a rRNA gene by eNoSC causes reduced expression of the gene. When glucose is low, NAD is high (NADH is low), activity of SIRT1 is high, and activity of rRNA genes is reduced. It is hypothesized that eNoSC forms on a nucleosome containing dimethylated lysine-9 on histone H3 (H3K9me2) and then eNoSC deacetylates and dimethylates the adjacent nucleosome, thus catalyzing spreading of H3K9me2 throughout the gene."
BMGC_PW1157,BMG_PW3602,,,"About half of the rRNA genes in the genome are actively expressed, being transcribed by RNA polymerase I (reviewed in Nemeth and Langst 2008, Bartova et al. 2010, Goodfellow and Zomerdijk 2012, Grummt and Langst 2013). As inferred from mouse, those genes that are expressed are activated by ERCC6 (also known as Cockayne Syndrome protein, CSB) which interacts with TTF-I bound to the T0 terminator region (also know as the Sal Box) of rRNA genes (Yuan et al. 2007, reviewed in Birch and Zomerdijk 2008, Grummt and Langst 2013). ERCC6 recruits the histone methyltransferase EHMT2 (also known as G9a) which dimethylates histone H3 at lysine-9 in the coding region of rRNA genes. The dimethylated lysine is bound by CBX3 (also known as Heterochromatic Protein-1gamma, HP1gamma) and increases expression of the rRNA gene. Continuing dimethylation depends on continuing transcription. Mutations in CSB result in dysregulation of RNA polymerase I transcription, which plays a role in the symptoms of Cockayne Syndrome (reviewed in Hannan et al. 2013)."
BMGC_PW1158,BMG_PW3603,,,"The Nucleolar Remodeling Complex (NoRC) comprising TIP5 (BAZ2A) and the chromatin remodeller SNF2H (SMARCA5) silences rRNA gene (reviewed in Santoro and Grummt 2001, Grummt 2007, Preuss and Pikaard 2007, Birch and Zommerdijk 2008, McStay and Grummt 2008, Grummt and Langst 2013). The TAM domain of TIP5 (BAZ2A) binds promoter-associated RNA (pRNA) transcribed from the intergenic spacer region of rDNA. The pRNA bound by TIP5 is required to direct the complex to the main promoter of the rRNA gene possibly by triple helix formation between pRNA and the rDNA. The PHD domain of TIP5 binds histone H4 acetylated at lysine-16. Transcription Termination Factor-I (TTF-I) binds to a promoter-proximal terminator (T0 site) in the rDNA and interacts with the TIP5 subunit of NoRC. NoRC also interacts with the SIN3-HDAC complex, HDAC1, HDAC2, DNMT1, and DNMT3B. DNMT3B interacts with a triple helix formed by pRNA and the rDNA. HDAC1, DNMT1, and DNMT3B have been shown to be required for proper DNA methylation of silenced rRNA gene copies, although the catalytic activity of DNMT3B was not required."
BMGC_PW1159,BMG_PW3604,,,"The SLC34 family of type II Na+/Pi cotransporters consist of three members; NaPi-IIa (SLC34A1), NaPi-IIb (SLC34A2) and NaPi-IIc (SLC34A3) (Murer H et al, 2004). They are expressed mainly in the kidney and small intestine, located at the apical sites of epithelial cells although other areas of the body express them to a lesser extent. NaPi-IIa and b cotransports divalent Pi (HPO4[2-]) with three Na+ ions (electrogenic transport) whereas NaPi-IIc cotransports divalent Pi with two Na+ ions (electroneutral transport)."
BMGC_PW1160,BMG_PW3605,,,"The human SLC26 gene family consists of eleven members which encode multifunctional anion exchangers.These exchangers are capable of transporting a variety of anions such as sulphate, bicarbonate, oxalate, hydroxyl, formate, iodide and chloride. SLC26 members can be grouped according to functional similiarities and three groups can be classified this way. Group 1 are selective sulphate transporters and include SLC26A1 and 2. Group 2 are Cl-/HCO3- exchangers and include SLC26A3, 4 and 6. Group 3 function as ion channels and include SLC26A7 and 9."
BMGC_PW1161,BMG_PW3606,,,"Phosphorus is an essential element that is critical for structural and metabolic roles in all living organisms. Cells obtain phosphorus in the form of negatively-charged inorganic phosphate (Pi). Two SLC families transport phosphate in mammals; SLC34 (Murer H et al, 2004) and SLC20 (Collins JF et al, 2004). Both are secondary-active, Na+-coupled transporter systems which use the inward Na+ gradient (from the Na+-K+-ATPase) to drive phosphate influx into cells (Virkki LV et al, 2007)."
BMGC_PW1162,BMG_PW3609,,,"A low level of RAC1 activity is essential to maintain axon outgrowth. ROBO activation recruits SOS, a dual specificity GEF, to the plasma membrane via Dock homolog NCK (NCK1 or NCK2) to activate RAC1 during midline repulsion."
BMGC_PW1163,BMG_PW3610,,,"Commissural axons project to the floor plate, attracted by the interaction of their DCC receptors with Netrin-1 (NTN1) produced by floor plate cells (Dickson and Gilestro 2006) and radial glia (Dominici et al. 2017, Varadarajan et al. 2017). Once an axon enters the floor plate, it must be efficiently expelled on the contralateral side. A switch from attraction to repulsion allows commissural axons to enter and then leave the CNS midline. Based on studies in Xenopus neurons and by yeast two hybrid screens, it is observed that the attractive response of axons to netrins is silenced by activation of ROBO. SLIT bound ROBO binds to DCC, preventing it from transducing an attractive response to netrin. The sensitivity of axons to the repulsive action of SLIT does not only depend on repulsive SLIT receptors (ROBO1 and ROBO2), but is also influenced by expression of ROBO3, a SLIT receptor that suppresses the activity of ROBO1 and ROBO2. Upon crossing the midline, commissural axons downregulate expression of ROBO3 and increase expression of ROBO1/ROBO2 (reviewed by Dickson and Gilestro, 2006). Two transcript variants of ROBO3, ROBO3.1 and ROBO3.2 are considered to play different roles in midline crossing. ROBO3.1 is expressed in the pre-crossing and crossing commissural axons, while ROBO3.2, generated by alternative splicing, is expressed after midline crossing and thought to block midline re-crossing (Chen et al. 2008). In addition to SLITs, a secreted ligand NELL2 also acts as an axonal guidance cue that, by acting through ROBO3 receptors, helps to steer commissural axons to the midline. Both ROBO3.1 and ROBO3.2 can bind to a secreted ligand NELL2. Pre-crossing commissural axons, which express ROBO3.1, are repelled by NELL2. Post-crossing axons, which express ROBO3.2 are not repelled by NELL2 (Jaworski et al. 2015). ."
BMGC_PW1164,BMG_PW3611,,,"Rho family GTPases, including RAC1, RHOA, and CDC42, are ideal candidates to regulate aspects of cytoskeletal dynamics downstream of axon guidance receptors. Biochemical and genetic studies have revealed an important role for CDC42 and RAC1 in ROBO repulsion. ROBO controls the activity of Rho GTPases by interacting with a family of SLIT/ROBO-specific GAPs (SrGAPs) and Vilse/CrossGAP. SrGAPs inactivate CDC42 and Vilse/CrossGAP specifically inactivates RAC1. It was recently implicated that SRGAP3 may inactivate RAC1 downstream of SLIT1-activated ROBO2, which promotes neurite outgrowth in mammalian dorsal root ganglion (DRG) neurons (Zhang et al. 2014)."
BMGC_PW1165,BMG_PW3613,,,"The SLC17 gene family encode proteins which are organic anion transporters. There are three distinct subfamilies within SLC17; vesicular glutamate transporters (VGLUT1-3 encoded by SLC17A7,6 and 8), type I Na+-coupled phosphate co-transporters (encoded by SLC17A1-4) and a proton-coupled sialic acid co-transporter (encoded by SLC17A5) (Reimer RJ and Edwards RH, 2004). Two members of the SLC5 gene family encode carboxylate transporters, SMCT1 and SMCT2 (Ganapathy V et al, 2008)."
BMGC_PW1166,BMG_PW3614,,,"ABL (ABL1 or ABL2) plays a dual role in the ROBO pathway. As a key enzymatic component in the signaling pathway, ABL supports repellent signaling (by recruiting the necessary actin binding proteins) and also feeds back on the receptor (by down regulating through phosphorylation) to adjust the sensitivity of the pathway. ABL cooperates with multiple effectors, including the actin binding protein Capulet (Capt) and Orbit/MAST/CLASP, suggesting that ABL simultaneously coordinates the dynamics of two major cytoskeletal systems to achieve growth cone repellent guidance."
BMGC_PW1167,BMG_PW3615,,,"Myo-Inositol is a neutral cyclic polyol, abundant in mammalian tissues. It plays important roles; it is a precursor to phosphatidylinositols (PtdIns) and to the inositol phosphates (IP), which serve as second messengers and as key regulators of many cell functions. It can also serve as a compatible osmolyte during volume regulation in many tissues where cells are exposed to hyperosmotic conditions. Three members of the glucose transporter families are inositol transporters. Two (SMIT1 and SMIT2) couple myo-inositol transport with two Na+ ions. Unlike SMIT1, SMIT2 also transports D-chiro_inositol. The third transporter (HMIT), couples myo-inositol transport with a proton."
BMGC_PW1168,BMG_PW3616,,,"After undergoing rounds of translation, mRNA is normally destroyed by the deadenylation-dependent pathway. Though the trigger is unclear, deadenylation likely proceeds in two steps: one catalyzed by the PAN2-PAN3 complex that shortens the poly(A) tail from about 200 adenosine residues to about 80 residues and one catalyzed by the CCR4-NOT complex or by the PARN enzyme that shortens the tail to about 10-15 residues. After deadenylation the mRNA is then hydrolyzed by either the 5' to 3' pathway or the 3' to 5' pathway. It is unknown what determinants target a mRNA to one pathway or the other. The 5' to 3' pathway is initiated by binding of the Lsm1-7 complex to the 3' oligoadenylate tail followed by decapping by the DCP1-DCP2 complex. The 5' to 3' exoribonuclease XRN1 then hydrolyzes the remaining RNA. The 3' to 5' pathway is initiated by the exosome complex at the 3' end of the mRNA. The exosome processively hydrolyzes the mRNA from 3' to 5', leaving only a capped oligoribonucleotide. The cap is then removed by the scavenging decapping enzyme DCPS."
BMGC_PW1169,BMG_PW3617,,,"Deadenylation of mRNA proceeds in two steps. According to current models, in the first step the poly(A) tail is shortened from about 200 adenosine residues to about 80 residues by the PAN2-PAN3 complex. In the second step the poly(A) tail is further shortened to 10-15 residues by either the CCR4-NOT complex or by the PARN exoribonuclease. How a particular mRNA is targeted to CCR4-NOT or PARN is unknown. A number of other deadenylase enzymes can be identified in genomic searches. One particularly interesting one is nocturin, a protein that is related to the CCR-1 deadenylase and plays a role in circadian rhythms. There is also evidence for networking between deadenylation and other aspects of gene expression. CCR4-NOT, for example, is known to be a transcription factor. PARN is part of a complex that regulates poly(A) tail length and hence translation in developing oocytes."
BMGC_PW1170,BMG_PW3618,,,"The degradation of mRNA from 3' to 5' occurs in two steps. First, the exosome exoribonuclease complex binds the 3' end of the oligoadenylated mRNA and hydrolyzes it from 3' to 5', yielding ribonucleotides having 5'-monophosphates, until a capped oligoribonucleotide remains. Second, the scavenging decapping enzyme DCPS hydrolyzes the 7-methylguanosine cap."
BMGC_PW1171,BMG_PW3619,,,"Degradation of mRNA from 5' to 3' occurs in three steps. First, the mRNA is bound at its 3' end by the Lsm1-7 complex. The bound Lsm1-7 may prevent nucleases from accessing the 3' end. Second, the 7-methylguanosine cap of the mRNA is hydrolyzed by the DCP1-DCP2 complex. Third, the 5' end of the decapped mRNA is attacked by the XRN1 exoribonuclease which digests the remainder of the mRNA from 5' to 3'. These processes may be physically connected by PATL1, the homolog of yeast Pat1, which stably binds the Lsm1-7 complex and interacts with the DCP1-DCP2 decapping complex and the Ccr4-NOT deadenylation complex (Ozgur et al. 2010)."
BMGC_PW1172,BMG_PW3620,,,"The platelet GPIb complex (GP1b-IX-V) together with GPVI are primarily responsible for regulating the initial adhesion of platelets to the damaged blood vessel and platelet activation. The importance of GPIb is demonstrated by the bleeding problems in patients with Bernard-Soulier syndrome where this receptor is either absent or defective. GP1b-IX-V binds von Willebrand Factor (vWF) to resting platelets, particularly under conditions of high shear stress. This transient interaction is the first stage of the vascular repair process. Activation of GP1b-IX-V on exposure of the fibrous matrix following atherosclerotic plaque rupture, or in occluded arteries, is a major contributory factor leading to thrombus formation leading to heart attack or stroke. GpIb also binds thrombin (Yamamoto et al. 1986), at a site distinct from the site of vWF binding, acting as a docking site for thrombin which then activates Proteinase Activated Receptors leading to enhanced platelet activation (Dormann et al. 2000)."
BMGC_PW1173,BMG_PW3621,,,Triglycerides stored in adipocytes are hydrolyzed to yield fatty acids and glycerol. The glycerol is passively transported out of the adipocyte and into the bloodstream by Aquaporin-7 (AQP7) located in the plasma membrane of adipocytes. Glycerol in the bloodstream is passively transported into liver cells by AQP9 located in the plasma membrane of hepatocytes. Once inside the liver cell the glycerol is a substrate for gluconeogenesis.
BMGC_PW1174,BMG_PW3622,,"In the kidney, the antidiuretic hormone vasopressin (AVP) is a critical regulator of water homeostasis by controlling the water movement from lumen to the interstitium for water reabsorption and adjusting the urinary water excretion. In normal physiology, AVP is secreted into the circulation by the posterior pituitary gland, in response to an increase in serum osmolality or a decrease in effective circulating volume. When reaching the kidney, AVP binds to V2 receptors on the basolateral surface of the collecting duct epithelium, triggering a G-protein-linked signaling cascade, which leads to water channel aquaporin-2 (AQP2) vesicle insertion into the apical plasma membrane. This results in higher water permeability in the collecting duct and, driven by an osmotic gradient, pro-urinary water then passes the membrane through AQP2 and leaves the cell on the basolateral side via AQP3 and AQP4 water channels, which are constitutively expressed on the basolateral side of these cells. When isotonicity is restored, reduced blood AVP levels results in AQP2 internalization, leaving the apical membrane watertight again.","In the kidney water and solutes are passed out of the bloodstream and into the proximal tubule via the slit-like structure formed by nephrin in the glomerulus. Water is reabsorbed from the filtrate during its transit through the proximal tubule, the descending loop of Henle, the distal convoluted tubule, and the collecting duct. Aquaporin-1 (AQP1) in the proximal tubule and the descending thin limb of Henle is responsible for about 90% of reabsorption (as estimated from mouse knockouts of AQP1). AQP1 is located on both the apical and basolateral surface of epithelial cells and thus transports water through the epithelium and back into the bloodstream. In the collecting duct epithelial cells have AQP2 on their apical surface and AQP3 and AQP4 on their basolateral surface to transport water across the epithelium. The permeability of the epithelium is regulated by vasopressin, which activates the phosphorylation and subsequent translocation of AQP2 from intracellular vesicles to the plasma membrane."
BMGC_PW1175,BMG_PW3623,,,"Aquaporins (AQP's) are six-pass transmembrane proteins that form channels in membranes. Each monomer contains a central channel formed in part by two asparagine-proline-alanine motifs (NPA boxes) that confer selectivity for water and/or solutes. The monomers assemble into tetramers. During passive transport by Aquaporins most aquaporins (i.e. AQP0/MIP, AQP1, AQP2, AQP3, AQP4, AQP5, AQP7, AQP8, AQP9, AQP10) transport water into and out of cells according to the osmotic gradient across the membrane. Four aquaporins (the aquaglyceroporins AQP3, AQP7, AQP9, AQP10) conduct glycerol, three aquaporins (AQP7, AQP9, AQP10) conduct urea, and one aquaporin (AQP6) conducts anions, especially nitrate. AQP8 also conducts ammonia in addition to water. AQP11 and AQP12, classified as group III aquaporins, were identified as a result of the genome sequencing project and are characterized by having variations in the first NPA box when compared to more traditional aquaporins. Additionally, a conserved cysteine residue is present about 9 amino acids downstream from the second NPA box and this cysteine is considered indicative of group III aquaporins. Purified AQP11 incorporated into liposomes showed water transport. Knockout mice lacking AQP11 had fatal cyst formation in the proximal tubule of the kidney. Exogenously expressed AQP12 showed intracellular localization. AQP12 is expressed exclusively in pancreatic acinar cells. Aquaporins are important in fluid and solute transport in various tissues. During Transport of glycerol from adipocytes to the liver by Aquaporins, glycerol generated by triglyceride hydrolysis is exported from adipocytes by AQP7 and is imported into liver cells via AQP9. AQP1 plays a role in forming cerebrospinal fluid and AQP1, AQP4, and AQP9 appear to be important in maintaining fluid balance in the brain. AQP0, AQP1, AQP3, AQP4, AQP8, AQP9, and AQP11 play roles in the physiology of the hepatobiliary tract. In the kidney, water and solutes are passed out of the bloodstream and into the proximal tubule via the slit-like structure formed by nephrin in the glomerulus. Water is reabsorbed from the filtrate during its transit through the proximal tubule, the descending loop of Henle, the distal convoluted tubule, and the collecting duct. Aquaporin-1 (AQP1) in the proximal tubule and the descending thin limb of Henle is responsible for about 90% of reabsorption (as estimated from mouse knockouts of AQP1). AQP1 is located on both the apical and basolateral surface of epithelial cells and thus transports water through the epithelium and back into the bloodstream. In the collecting duct epithelial cells have AQP2 on their apical surfaces and AQP3 and AQP4 on their basolateral surfaces to transport water across the epithelium. Vasopressin regulates renal water homeostasis via Aquaporins by regulating the permeability of the epithelium through activation of a signaling cascade leading to the phosphorylation of AQP2 and its translocation from intracellular vesicles to the apical membrane of collecting duct cells. Here, three views of aquaporin-mediated transport have been annotated: a generic view of transport mediated by the various families of aquaporins independent of tissue type (Passive transport by Aquaporins), a view of the role of specific aquaporins in maintenance of renal water balance (Vasopressin regulates renal water homeostasis via Aquaporins), and a view of the role of specific aquaporins in glycerol transport from adipocytes to the liver (Transport of glycerol from adipocytes to the liver by Aquaporins)."
BMGC_PW1176,BMG_PW3624,,,"Physiological concentrations (1g/L) of Low density lipoprotein (LDL) enhance platelet aggregation responses initiated by thrombin, collagen, and ADP. This enhancement involves the rapid phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) at Thr180 and Tyr182. The receptor for LDL is ApoER2, a splice variant of the classical ApoE receptor. ApoER2 stimulation leads to association of the Src family kinase Fgr which is probably responsible for subsequent phosphorylation of p38MAPK. This stimulation is transient because LDL also increases the activity of PECAM-1, which stimulates phosphatases that dephosphorylate p38MAPK."
BMGC_PW1177,BMG_PW3625,,,"Proteins that have been synthesized, processed and sorted eventually reach the final steps of the secretory pathway. This pathway is responsible not only for proteins that are secreted from the cell but also enzymes and other resident proteins in the lumen of the ER, Golgi, and lysosomes as well as integral proteins transported in the vesicle membranes. Here the proteins in this secretory pathway are ultimately found in lysososmes."
BMGC_PW1178,BMG_PW3626,,,"Proteins that have been synthesized, processed and sorted eventually reach the final steps of the secretory pathway. This pathway is responsible not only for proteins that are secreted from the cell but also enzymes and other resident proteins in the lumen of the ER, Golgi, and lysosomes as well as integral proteins transported in the vesicle membranes."
BMGC_PW1179,BMG_PW3627,,,"Five human SLC13 genes encode sodium-coupled sulphate, di- and tri-carboxylate transporters located on the plasma membrane. Two transporters (NaS1 and NaS2) co-transport sulphate with sodium. The other members (NaDC1, NaDC3, and NaCT) co-transport sodium with di- and tri-carboxylates such as succinate, citrate and alpha-ketoglutarate (Pajor AM, 2006)."
BMGC_PW1180,BMG_PW3628,,,"The SLC16A gene family encode proton-linked monocarboxylate transporters (MCT) which mediate the transport of monocarboxylates such as lactate and pyruvate. Monocarboxylates are a major energy source for all cells in the body so their transport in and out of cells is crucial for cellular function. To date, 14 SLC16A members have been identified through sequence homology. Of these 14 members, only seven isoforms have been functionally characterized and not all of these function as proton-coupled transporters. A number can transport diuretics, thyroid hormones and aromatic amino acids. The seven remaining SLC16A members are classed as orphan MCTs (Morris & Felmlee 2008, Merezhinskaya & Fishbein 2009). In mammalian cells, MCTs (monocarboxylate transporters) require association with an ancillary protein to enable plasma membrane expression of the active transporter. Basigin (BSG, CD147) is the preferred binding partner for MCT1, MCT3 and MCT4, while MCT2 requires Embigin (EMB) (Wilson et al. 2005)."
BMGC_PW1181,BMG_PW3631,,,"Fatty acids augment the glucose triggered secretion of insulin through two mechanisms: intracellular metabolism and activation of FFAR1 (GPR40), a G-protein coupled receptor. Based on studies with inhibitors of G proteins such as pertussis toxin FFAR1 is believed to signal through Gq/11. Binding of free fatty acids by FFAR1 activates the heterotrimeric Gq complex which then activates Phospholipase C, producing inositol 1,4,5-trisphosphate and eventually causing the release of intracellular calcium into the cytosol. From experiments in knockout mice it is estimated that signaling through FFAR1 is responsible for about 50% of the augmentation of insulin secretion produced by free fatty acids."
BMGC_PW1182,BMG_PW3632,,,"Zinc is an essential element for all organisms because it serves as a catalytic or structural cofactor for many different proteins. Cellular zinc homoeostasis is co-ordinated through Zn2+-specific transporters which are members of two distinct gene families. Members of the SLC39 gene family (ZRTL-like import proteins1-14, ZIP1-14) are responsible for Zn2+ import into the cytoplasm, either across the plasma membrane or out of intracellular organelles. In contrast, members of the SLC30 gene family (zinc transporters 1-10, ZnT1-10) export Zn2+ from the cytoplasm, either across the plasma membrane into the extracellular space or into intracellular organelles (Murakami M and Hirano T, 2008; Devirgiliis C et al, 2007; Eide DJ, 2006)."
BMGC_PW1183,BMG_PW3633,,,"The human SLC30 gene family of solute carriers is thought to participate in the homeostasis of zinc ions and facilitate zinc transport into specialized compartments of the cell such as endosomes, golgi network and synaptic vesicles. There are 10 members of this family, named ZnT1-10. ZnT4, ZnT9 and ZnT10 have no function determined as of yet (Palmiter RD and Huang L, 2004)."
BMGC_PW1184,BMG_PW3634,,,"L1 functions in many aspects of neuronal development including axon outgrowth and neuronal migration. These functions require coordination between L1 and the actin cytoskeleton. F-actin continuously moves in a retrograde direction from the P-(peripheral) domain of the growth cone towards the growth cone's C-(central) domain. L1, attached to the actin cytoskeleton via membrane cytoskeletal linkers (MCKs) such as ankyrins (Ankyrin-G, -B and -R) and members of the ERMs (ezrin, radixin, and moesin) family, link this retrograde F-actin flow with extracellular immobile ligands. Forward translocation of growth cone requires not only the CAM-actin linkage but also a gradient of cell substrate adhesion (strong adhesion at the front and weak adhesion at the rear) so that the cytoskeletal machinery is able to pull the cell forward as attachments at the rear are released. This asymmetry is achieved in part by internalizing L1 molecules as they are moved to the rear of the growth cone coupled to retrograde F-actin flow and recycling them to the leading edge plasma membrane. L1 internalization is mediated by phosphorylation and dephosphorylation. The L1 cytoplasmic domain (L1CD) carries an endocytic or sorting motif, YRSLE, that is recognized by the clathrin associated adaptor protein-2 (AP-2). AP-2 binds the YRSLE motif only when its tyrosine is not phosphorylated and triggers L1 endocytosis. SRC kinase associated with lipid rafts in the P-domain membrane phosphorylates L1 molecules on tyrosine-1176, stabilizing them in the plasma membrane. L1 endocytosis is triggered by the dephosphorylation of Y1176 within the C domain. Some of these internalized L1 molecules are transported in an anterograde direction along microtubules for reuse in the leading edge."
BMGC_PW1185,BMG_PW3635,,,"Ca2+ influx through the NMDA receptor initiates subsequent molecular pathways that have a defined role in establishing long-lasting synaptic changes. The molecular signaling initiated by a rise in Ca2+ within the spine leads to phosphorylation of Cyclic AMP Response Element binding protein (CREB1) at serine S133, leading to transcription of genes involved in long lasting changes at the synapse. The phosphorylation of CREB1 triggered by increased Ca2+ can be brought about by distinct molecular pathways that may involve MAP kinase, activation of adenylate cyclase and activation of CaMKIV (reviewed by Cohen and Greenberg 2008 and Hunt and Castillo 2012)."
BMGC_PW1186,BMG_PW3636,,,"At resting membrane potential, the NMDA receptor ion channel is blocked by extracellular Mg2+ ions and is unable to mediate ion permeation upon binding of ligands (glutamate, glycine, D-serine, NMDA). The voltage block is removed upon depolarization of the post-synaptic cell membrane and Mg2+ is expelled from the NMDA receptor pore (channel), resulting in activated ligand-bound NMDA receptors. The depolarization of the membrane may happen in response to activation of Ca2+ impermeable AMPA receptors, which facilitates Na+ influx, contributing to the unblocking of NMDA receptors. For review, please refer to Traynelis et al. 2010, Paoletti et al. 2013, and Iacobucci and Popescu 2017."
BMGC_PW1187,BMG_PW3637,,,"The genes regulated by beta-catenin and TCF/LEF are involved in a diverse range of functions in cellular proliferation, differentiation, embryogenesis and tissue homeostasis, and include transcription factors, cell cycle regulators, growth factors, proteinases and inflammatory cytokines, among others (reviewed in Vlad et al, 2008). A number of WNT signaling components are themselves positively or negatively regulated targets of TCF/LEF-dependent transcription, establishing feedback loops to enhance or restrict signaling (see for instance, Khan et al 2007; Chamorro et al, 2005; Roose et al, 1999; Lustig et al, 2002). Other than a few of these general feedback targets (e.g. Axin2), most target genes are cell- and/or tissue-specific. A list of WNT/beta-catenin-dependent target genes is maintained at http://www.standford.edu/group/nusselab/cgi-bin/wnt/target_genes."
BMGC_PW1188,BMG_PW3638,,,"The nuclear envelope breakdown in mitotic prophase involves depolymerization of lamin filaments, the main constituents of the nuclear lamina. The nuclear lamina is located at the nuclear face of the inner nuclear membrane and plays and important role in the structure and function of the nuclear envelope (reviewed by Burke and Stewart 2012). Depolymerization of lamin filaments, which consist of lamin homodimers associated through electrostatic interactions in head-to-tail molecular strings, is triggered by phosphorylation of lamins. While CDK1 phosphorylates the N-termini of lamins (Heald and McKeon 1990, Peter et al. 1990, Ward and Kirschner 1990, Mall et al. 2012), PKCs (PRKCA and PRKCB) phosphorylate the C-termini of lamins (Hocevar et al. 1993, Goss et al. 1994, Mall et al. 2012). PKCs are activated by lipid-mediated signaling, where lipins, activated by CTDNEP1:CNEP1R1 serine/threonine protein phosphatase complex, catalyze the formation of DAG (Gorjanacz et al. 2009, Golden et al. 2009, Wu et al. 2011, Han et al. 2012, Mall et al. 2012)."
BMGC_PW1189,BMG_PW3639,,,"Angiogenesis is the formation of new blood vessels from preexisting vasculature. One of the most important proangiogenic factors is vascular endothelial growth factor (VEGF). VEGF exerts its biologic effect through interaction with transmembrane tyrosine kinase receptors VEGFR, selectively expressed on vascular endothelial cells. VEGFA signaling through VEGFR2 is the major pathway that activates angiogenesis by inducing the proliferation, survival, sprouting and migration of endothelial cells (ECs), and also by increasing endothelial permeability (Lohela et al. 2009, Shibuya & Claesson-Welsh 2006, Claesson-Welsh & Welsh, 2013). The critical role of VEGFR2 in vascular development is highlighted by the fact that VEGFR2-/- mice die at E8.5-9.5 due to defective development of blood islands, endothelial cells and haematopoietic cells (Shalaby et al. 1995)."
BMGC_PW1190,BMG_PW3640,,,"The biosynthesis of dermatan sulfate/chondroitin sulfate and heparin/heparan sulfate glycosaminoglycans (GAGs) starts with the formation of a tetrasaccharide linker sequence attached to the core protein. Beta-1,3-galactosyltransferase 6 (B3GALT6) is one of the critical enzymes involved in the formation of this linker sequence. Defects in B3GALT6 causes Ehlers-Danlos syndrome progeroid type 2 (EDSP2; MIM:615349), a severe disorder resulting in a broad spectrum of skeletal, connective tissue and wound healing problems. Defects in B3GALT6 can also cause spondyloepimetaphyseal dysplasia with joint laxity type 1 (SEMDJL1; MIM:271640), characterised by spinal deformaty and lax joints, especially of the hands and respiratory compromise resulting in early death (Nakajima et al. 2013, Malfait et al. 2013)."
BMGC_PW1191,BMG_PW3641,,,"The SLC39 gene family encode zinc transporters belonging to the ZIP (Zrt-, Irt-like proteins) family of metal ion transporters. All ZIPs transport metal ions into the cytoplasm of cells, be it across cellular membranes or from intracellular compartments. To date, there are 14 human SLC39 genes that encode the zinc transporters hZIP1-14. There are 9 members which belong to a subfamily of the ZIPs called the LZTs (LIV-1 subfamily of ZIP zinc transporters) (Taylor KM and Nicholson RI, 2003). Of these 14 proteins, four (hZIP9, 11, 12 and 13) have no function determined yet (Eide DJ, 2004)."
BMGC_PW1192,BMG_PW3642,,,"The SLC6 gene family encodes proteins that mediate neurotransmitter uptake thus terminating a synaptic signal. The proteins mediate transport of GABA (gamma-aminobutyric acid), norepinephrine, dopamine, serotonin, glycine, taurine, L-proline, creatine and betaine. These transporters are mainly present in the CNS and PNS (Chen NH et al, 2004)."
BMGC_PW1193,BMG_PW3643,,,"Ca2+ influx through activated NMDA receptors in the post synaptic neurons activates adenylate cyclase-mediated signal transduction, leading to the activation of PKA and phosphorylation and activation of CREB1 induced transcription (Masada et al. 2012, Chetkovich et al. 1991, Chetkovich and Sweatt 1993"
BMGC_PW1194,BMG_PW3644,,,"In addition to inducing long-term potentiation (LTP), NMDA receptor-mediated activation of CaMKII leads to transcriptional changes that are implicated in LTP maintenance (reviewed by Miyamoto 2006). CaMKII-gamma (CAMK2G) isoform is involved in nuclear shuttling of the calcium/calmodulin complex (CALM1:4xCa2+), which enables CaMKK-mediated activation of the nuclear calcium/calmodulin dependent kinase CaMKIV (CAMK4). Activated CaMKIV phosphorylates the transcription factor CREB1 and activates CREB1-mediated transcription (Ma et al. 2014, Cohen et al. 2018)."
BMGC_PW1195,BMG_PW3645,,,"Ca2+ influx through the NMDA receptor activates RAS guanyl nucleotide exchange factor RasGRF, which promotes formation of active RAS:GTP complexes (Anborgh et al. 1999, Krapivinsky et al. 2003). CaMKII, also activated by NMDA receptor-mediated Ca2+ influx, can contribute to activation of RAS/RAF/MAPK signaling by phosphorylation of RAF1 (Salzano et al. 2012). ERKs (MAPK1 and MAPK3), activated downstream of RAS signaling, phosphorylate ribosomal protein S6 kinases (RSKs), initiating activation of RSKs (reviewed by Anjum and Blenis 2012). Activated RSKs phosphorylate the transcription factor CREB1 at serine residue S133, thus stimulating CREB1-mediated transcription (De Cesare et al. 1998, Harum et al. 2001, Schinelli et al. 2001, Song et al. 2003)."
BMGC_PW1196,BMG_PW3646,,,Ca2+ influx through the NMDA receptor triggers RAS signaling through the activation of RAS guanyl nucleotide exchange factor RasGRF (Krapivinsky et al. 2003).
BMGC_PW1197,BMG_PW3648,,,"Ribosomal S6 kinase (RSK) has four isoforms in humans, RPS6KA1 (RSK1), RPS6KA2 (RSK3), RPS6KA3 (RSK2) and RPS6KA6 (RSK4), and each of the isoforms have six conserved phosphorylation sites (in RPS6KA1, these are serine residues S221, S363 and S380 and threonine residues T359, T573 and T732). Phosphorylation at four of these residues appears to be critically important for the catalytic activity of RSKs: S221, S363, S380 and T573 (in RPS6KA1). Phosphorylation and activation of RSKs primarily occurs at the plasma membrane, but can occur in the cytoplasm and in the nucleus. ERKs (MAPK1 and MAPK3), activated downstream of RAS signaling, phosphorylate RSKs on threonine and serine residues T359, S363 and T573 (in RPS6KA1). Phosphorylation by ERKs enables autophosphorylation of RSKs on serine residue S380 and threonine residue T732 (in RPS6KA1). Phosphorylation of RSKs by PDPK1 (PDK1) at serine residue S221 (in RPS6KA1) is necessary for the full activation of RSKs and phosphorylation of RSK substrates (reviewed by Anjum and Blenis 2012). RSK4 differs from other RSKs because it shows high level of constitutive phosphorylation and activity in the absence of growth factors, although it is still responsive to growth factors and ERK activity (Dummler et al. 2005). RSKs, especially RSK2, are highly expressed in brain regions with high synaptic activity. RSK2 mutations are the underlying cause of Coffin-Lowry syndrome (CLS), which is characterized by cognitive impairment and skeletal anomalies (Zeniou et al. 2002)."
BMGC_PW1198,BMG_PW3649,,,"The Rhesus (Rh) glycoproteins were originally described in human blood cells as potent immunogens. There are three Rh glycoproteins in humans; an erythroid-specific Rh-associated glycoprotein (RhAG) and two non-erythroid Rh glycoproteins, RhBG and RhCG. These proteins are related to ammonium (NH4+) transporters of yeast and bacteria (methylammonium and ammonium permease and ammonium transporter, MEP/Amt) (Nakhoul NL and Hamm LL, 2004; Planelles G, 2007)."
BMGC_PW1199,BMG_PW3650,,,"The formyl peptide receptor (FPR) was defined pharmacologically in 1976 as a high affinity binding site on the surface of neutrophils for the peptide N-formyl-methionine-leucine-phenylalanine (fMLF). FPR was cloned in 1990 and the cDNA used as a probe to identify two additional genes, FPRL1 and FPRL2. The three genes for a cluster on 19q13.3. All are coupled to the Gi family of G proteins. All 3 receptors can be activated by formyl peptides but also display affinities for a range of structurally diverse ligands."
BMGC_PW1200,BMG_PW3652,,,"Ankyrins are a family of adaptor proteins that couple membrane proteins such as voltage gated Na+ channels and the Na+/K+ anion exchanger to the spectrin actin cytoskeleton. Ankyrins are encoded by three genes (ankyrin-G, -B and -R) of which ankyrin-G and -B are the major forms expressed in the developing nervous system. Ankyrins bind to the cytoplasmic domain of L1 CAMs and couple them and ion channel proteins, to the spectrin cytoskeleton. This binding enhances the homophilic adhesive activity of L1 and reduces its mobility within the plasma membrane. L1 interaction with ankyrin mediates branching and synaptogenesis of cortical inhibitory neurons."
BMGC_PW1201,BMG_PW3653,,,"Besides adhesive roles in cell cell interaction, L1 functions as a signal transducing receptor providing neurons with cues from their environment for axonal growth and guidance. L1 associates with beta1 integrins on the cell surface to induce a signaling pathway involving sequential activation of pp60csrc, Vav2 -GEF, Rac1, PAK1, MEK and ERK1/2. L1 stimulates cell migration and neurite outgrowth through the MAP kinases ERK1/2. CHL1 also associates with integrins and activates a MAPK signaling pathway via pp60c-src, MEK and ERK1/2. L1 also binds the Sema3A receptor neuropilin1 and acts as an obligate coreceptor to mediate Sema3A induced growth cone collapse and axon repulsion. This repulsion can be converted to attraction by homophilic binding of L1 on an apposing cell in trans with L1 complexed with Neuropilin1 (NP1) in the responding neuron. L1 also interacts with FGF receptor and activates PLC gamma and DAG, resulting in the production of arachidonic acid and subsequent opening of voltage-gated channels."
BMGC_PW1202,BMG_PW3654,,,"NF-kappa-B is sequestered in the cytoplasm in a complex with inhibitor of NF-kappa-B (IkB). Almost all NF-kappa-B activation pathways are mediated by IkB kinase (IKK), which phosphorylates IkB resulting in dissociation of NF-kappa-B from the complex. This allows translocation of NF-kappa-B to the nucleus where it regulates gene expression."
BMGC_PW1203,BMG_PW3655,,,"Hemidesmosomes (HDs) are specialized multiprotein junctional complexes that connect the keratin cytoskeleton of epithelial cells to the extracellular matrix and play a critical role in the maintenance of tissue structure and integrity (reviewed in Litjens et al., 2006). HDs mediate adhesion of epithelial cells to the underlying basement membrane in stratified squamous, transitional and pseudostratified epithelia (Jones et al., 1994 ; Borradori and Sonnenberg, 1996). Classical Type I HDs are found in stratified and pseudo-stratified epithelia, such as the skin, and contain a6b4, plectin, tetraspanin CD151 and the bullous pemphigoid (BP) antigens BP180 and BP230 (reviewed in Litjens et al., 2006). While HDs function in promoting stable adhesion, they are highly dynamic structures that are able to disassemble quickly, for example, during cell division, differentiation, or migration (see Margadant et al, 2008)."
BMGC_PW1204,BMG_PW3656,,,"N-linked glycosylation commences with the 14-step synthesis of a dolichol lipid-linked oligosaccharide (LLO) consisting of 14 sugars (2 core GlcNAcs, 9 mannoses and 3 terminal GlcNAcs). This pathway is highly conserved in eukaryotes, and a closely related pathway is found in many eubacteria and Archaea. Mutations in the genes associated with N-glycan precursor synthesis lead to a diverse group of disorders collectively known as Congenital Disorders of Glycosylation (type I and II) (Sparks et al. 1993). The phenotypes of these disorders reflect the important role that N-glycosylation has during development, controlling the folding and the properties of proteins in the secretory pathway, and proteins that mediate cell-to-cell interactions or timing of development."
BMGC_PW1205,BMG_PW3657,,,"Dolichol is a polyisoprenol lipid comprised of five-carbon isoprene units linked linearly in a head-to-tail fashion. Almost all eukaryotic membranes contain dolichol and its phosphorylated form is used in the N-glycosylation of proteins where it is used as an anchor for the N-glycan sugar to the ER membrane, and as an initiation point for the synthesis. Dolichol biosynthesis occurs on the cytoplasmic face of the ER membrane, which is where N-glycosylation occurs too, so is perfectly placed to serve as a substrate for this process. Dolichyl phosphate can be obtained either from direct phosphorylation of dolichol, formed in a series of reactions from mevalonate 5-pyrophosphate, or a salvage reaction by de-phosphorylation of dolichyl diphosphate, released at the end of N-glycan biosynthesis (Cantagrel & Lefeber 2011)."
BMGC_PW1206,BMG_PW3658,,,"N-linked glycosylation is the most important form of post-translational modification for proteins synthesized and folded in the Endoplasmic Reticulum (Stanley et al. 2009). An early study in 1999 revealed that about 50% of the proteins in the Swiss-Prot database at the time were N-glycosylated (Apweiler et al. 1999). It is now established that the majority of the proteins in the secretory pathway require glycosylation in order to achieve proper folding. The addition of an N-glycan to a protein can have several roles (Shental-Bechor & Levy 2009). First, glycans enhance the solubility and stability of the proteins in the ER, the golgi and on the outside of the cell membrane, where the composition of the medium is strongly hydrophilic and where proteins, that are mostly hydrophobic, have difficulty folding properly. Second, N-glycans are used as signal molecules during the folding and transport process of the protein: they have the role of labels to determine when a protein must interact with a chaperon, be transported to the golgi, or targeted for degradation in case of major folding defects. Third, and most importantly, N-glycans on completely folded proteins are involved in a wide range of processes: they help determine the specificity of membrane receptors in innate immunity or in cell-to-cell interactions, they can change the properties of hormones and secreted proteins, or of the proteins in the vesicular system inside the cell. All N-linked glycans are derived from a common 14-sugar oligosaccharide synthesized in the ER, which is attached co-translationally to a protein while this is being translated inside the reticulum. The process of the synthesis of this glycan, known as Synthesis of the N-glycan precursor or LLO, constitutes one of the most conserved pathways in eukaryotes, and has been also observed in some eubacteria. The attachment usually happens on an asparagine residue within the consensus sequence asparagine-X-threonine by an complex called oligosaccharyl transferase (OST). After being attached to an unfolded protein, the glycan is used as a label molecule in the folding process (also known as Calnexin/Calreticulin cycle) (Lederkremer 2009). The majority of the glycoproteins in the ER require at least one glycosylated residue in order to achieve proper folding, even if it has been shown that a smaller portion of the proteins in the ER can be folded without this modification. Once the glycoprotein has achieved proper folding, it is transported via the cis-Golgi through all the Golgi compartments, where the glycan is further modified according to the properties of the glycoprotein. This process involves relatively few enzymes but due to its combinatorial nature, can lead to several millions of different possible modifications. The exact topography of this network of reactions has not been established yet, representing one of the major challenges after the sequencing of the human genome (Hossler et al. 2006). Since N-glycosylation is involved in an great number of different processes, from cell-cell interaction to folding control, mutations in one of the genes involved in glycan assembly and/or modification can lead to severe development problems (often affecting the central nervous system). All the diseases in genes involved in glycosylation are collectively known as Congenital Disorders of Glycosylation (CDG) (Sparks et al. 2003), and classified as CDG type I for the genes in the LLO synthesis pathway, and CDG type II for the others."
BMGC_PW1207,BMG_PW3659,,,"GDP-mannose is the mannose donor for the first 5 mannose addition reactions in the N-glycan precursor synthesis, and also for the synthesis of Dolichyl-phosphate-mannose involved in other mannose transfer reactions. It is synthesized from fructose 6-phosphate and GTP in three steps."
BMGC_PW1208,BMG_PW3660,,,"UDP-acetylglucosamine acts as a donor for the first two steps of the N-glycan precursor biosynthesis pathway, and is later used as a substrate for further modifications after the precursor has been attached to the protein. It is synthesized from fructose 6-phosphate, glutamine, acetyl-CoA, and UTP in four steps."
BMGC_PW1209,BMG_PW3661,,,"Reactions for the synthesis of the small nucleotide-linked sugar substrates that are used in the synthesis of the N-glycan precursor and in the later steps of glycosylation are annotated here. All these nucleotide-linked sugar donors are synthesized in the cytosol; however, to participate in the later reactions of N-glycan precursor biosynthesis (when the glycan is oriented toward the lumen of the endoplasmic reticulum (ER)), these substrates must be attached to a dolichyl-phosphate molecule and then flipped toward the luminal side of the ER, through a mechanism which is still not known but which involves a different protein than the one that mediates the flipping of the LLO itself (Sanyal et al. 2008). Two of the genes encoding enzymes involved in these reactions, MPI and PMM2, are known to be associated with Congenital Disorders of Glycosylation (CDG) diseases of type I. Of these, CDG-Ia, associated with defects in PMM2, is the most frequent CDG disease reported."
BMGC_PW1210,BMG_PW3662,,,"The interactions among ILK, PINCH, and parvins are necessary but not sufficient for localization of ILK to cell-ECM adhesions (Zhang et al., 2002). Additional proteins that interact with PINCH-ILK-parvin complex components likely participate in mediating its localization (reviewed in Wu, 2004)."
BMGC_PW1211,BMG_PW3663,,,"Cell-extracellular matrix (ECM) interactions play a critical role in regulating a variety of cellular processes in multicellular organisms including motility, shape change, survival, proliferation and differentiation. Cell-ECM contact is mediated by transmembrane cell adhesion receptors, such as integrins, that interact with extracellular matrix proteins as well as a number of cytoplasmic adaptor proteins. Many of these adaptor proteins physically interact with the actin cytoskeleton or function in signal transduction. Several protein complexes interact with the cytoplasmic tail of integrins and function in transducing bi-directional signals between the ECM and intracellular signaling pathways (reviewed in Sepulveda et al., 2005). Early events that are triggered by interactions with ECM, such as formation/turnover of Focal Adhesions, regulation of actin dynamics and protrusion of lamellipodia to promote cellular spreading and motility are modulated by PINCH- ILK- parvin complexes (see Sepulveda et al., 2005). A number of partners of the PINCH-ILK-parvin complex components have been identified that regulate and/or mediate the functions of these complexes (reviewed in Wu, 2004). Interactions with some of these partners modulate cytoskeletal remodeling and cell spreading."
BMGC_PW1212,BMG_PW3664,,,"The PINCH-ILK-Parvin complexes function in transducing diverse signals from ECM to intracellular effectors. Interacting partners for components of these complexes have been identified, a number of which regulate and/or mediate its functions in cytoskeletal remodeling and cell spreading (reviewed in Wu, 2004)."
BMGC_PW1213,BMG_PW3665,,,"Cell junction organization in Reactome currently covers aspects of cell-cell junction organization, cell-extracellular matrix interactions, and Type I hemidesmosome assembly."
BMGC_PW1214,BMG_PW3666,,,The NgCAM-related cell adhesion molecule (NrCAM) is member of the L1 family involved in the eye development and node of Ranvier. Like all the other members of L1 family NrCAM also has the ability to bind to ankyrins. The last C-terminal amino acids of NrCAM form a PDZ-binding motif and can interact with SAP (synapse-associated protein) 102 and SAP97. Member of the GPI-anchored TAG-1/axonin-1 have been shown to interact with NrCAM. NrCAM also binds the Sema3B receptor NP-2 to mediate repulsive axon guidance.
BMGC_PW1215,BMG_PW3667,,,"Close homolog of L1 (CHL1) is a member of the L1 family of cell adhesion molecules expressed by subpopulations of neurons and glia in the central and peripheral nervous system. CHL1 like L1 promotes neuron survival and neurite outgrowth. CHL1 shares the basic structural arrangement of L1 family members yet in contrast to all the members it is not capable of forming homophilic adhesion. The second Ig-like domain of CHL1 contains the integrin interaction motif RGD rather than with in the sixth Ig-like domain as in L1, however the sixth Ig-like domain of CHL1 has another potential integrin binding motif DGEA. CHL1 binds NP-1 via the Ig1 sequence FASNRL to mdediate repulsive axon guidance to Sema3A. CHL1 is the only L1 family member with an altered sequence (FIGAY) in the ankyrin-binding domain, and it lacks the sorting/endocytosis RSLE motif, which is characteristic of other L1 family members."
BMGC_PW1216,BMG_PW3668,,,Neurofascin is an L1 family immunoglobulin cell adhesion molecule involved in axon subcellular targeting and synapse formation during neural development. There are a range of different isoforms identified in Neurofascin of which two of them are well studied the 186kDa commonly referred to as neuronal form and is present in node of Ranvier neurons and the 155kDa form known as a glial form present in schwann cells. Neurofascin colocalizes with NrCAM and ankyrinG at the nodes of Ranvier. Neurofascin participates in transheterophilic adhesion with NrCAM and stimulates neurite outgrowth in chicken tectal neurons. The last few amino acids of neurofascin form the PDZ class I binding motif (SLA) and through these last few amino acids it associates with syntenin-1.
BMGC_PW1217,BMG_PW3669,,,"The IL-1 family of cytokines that interact with the Type 1 IL-1R include IL-1α (IL1A), IL-1β (IL1B) and the IL-1 receptor antagonist protein (IL1RAP). IL1RAP is synthesized with a signal peptide and secreted as a mature protein via the classical secretory pathway. IL1A and IL1B are synthesised as cytoplasmic precursors (pro-IL1A and pro-IL1B) in activated cells. They have no signal sequence, precluding secretion via the classical ER-Golgi route (Rubartelli et al. 1990). Processing of pro-IL1B to the active form requires caspase-1 (Thornberry et al. 1992), which is itself activated by a molecular scaffold termed the inflammasome (Martinon et al. 2002). Processing and release of IL1B are thought to be closely linked, because mature IL1B is only seen inside inflammatory cells just prior to release (Brough et al. 2003). It has been reported that in monocytes a fraction of cellular IL1B is released by the regulated secretion of late endosomes and early lysosomes, and that this may represent a cellular compartment where caspase-1 processing of pro-IL1B takes place (Andrei et al. 1999). Shedding of microvesicles from the plasma membrane has also been proposed as a mechanism of secretion (MacKenzie et al. 2001). These proposals superceded previous models in which non-specific release due to cell lysis and passage through a plasma membrane pore were considered. However, there is evidence in the literature that supports all of these mechanisms and there is still controversy over how IL1B exits from cells (Brough & Rothwell 2007). A calpain-like potease has been reported to be important for the processing of pro-IL1A, but much less is known about how IL1A is released from cells and what specific roles it plays in biology."
BMGC_PW1218,BMG_PW3671,,,"MAPKs are protein kinases that, once activated, phosphorylate their specific cytosolic or nuclear substrates at serine and/or threonine residues. Such phosphorylation events can either positively or negatively regulate substrate, and thus entire signaling cascade activity. The major cytosolic target of activated ERKs are RSKs (90 kDa Ribosomal protein S6 Kinase). Active RSKs translocates to the nucleus and phosphorylates such factors as c-Fos(on Ser362), SRF (Serum Response Factor) at Ser103, and CREB (Cyclic AMP Response Element-Binding protein) at Ser133. In the nucleus activated ERKs phosphorylate many other targets such as MSKs (Mitogen- and Stress-activated protein kinases), MNK (MAP interacting kinase) and Elk1 (on Serine383 and Serine389). ERK can directly phosphorylate CREB and also AP-1 components c-Jun and c-Fos. Another important target of ERK is NF-KappaB. Recent studies reveals that nuclear pore proteins are direct substrates for ERK (Kosako H et al, 2009). Other ERK nuclear targets include c-Myc, HSF1 (Heat-Shock Factor-1), STAT1/3 (Signal Transducer and Activator of Transcription-1/3), and many more transcription factors. Activated p38 MAPK is able to phosphorylate a variety of substrates, including transcription factors STAT1, p53, ATF2 (Activating transcription factor 2), MEF2 (Myocyte enhancer factor-2), protein kinases MSK1, MNK, MAPKAPK2/3, death/survival molecules (Bcl2, caspases), and cell cycle control factors (cyclin D1). JNK, once activated, phosphorylates a range of nuclear substrates, including transcription factors Jun, ATF, Elk1, p53, STAT1/3 and many other factors. JNK has also been shown to directly phosphorylate many nuclear hormone receptors. For example, peroxisome proliferator-activated receptor 1 (PPAR-1) and retinoic acid receptors RXR and RAR are substrates for JNK. Other JNK targets are heterogeneous nuclear ribonucleoprotein K (hnRNP-K) and the Pol I-specific transcription factor TIF-IA, which regulates ribosome synthesis. Other adaptor and scaffold proteins have also been characterized as nonnuclear substrates of JNK."
BMGC_PW1219,BMG_PW3672,,,"The mitogen activated protein kinase (MAPK) cascade, one of the most ancient and evolutionarily conserved signaling pathways, is involved in many processes of immune responses. The MAP kinases cascade transduces signals from the cell membrane to the nucleus in response to a wide range of stimuli (Chang and Karin, 2001; Johnson et al, 2002). There are three major groups of MAP kinases the extracellular signal-regulated protein kinases ERK1/2, the p38 MAP kinase and the c-Jun NH-terminal kinases JNK. ERK1 and ERK2 are activated in response to growth stimuli. Both JNKs and p38-MAPK are activated in response to a variety of cellular and environmental stresses. The MAP kinases are activated by dual phosphorylation of Thr and Tyr within the tripeptide motif Thr-Xaa-Tyr. The sequence of this tripeptide motif is different in each group of MAP kinases: ERK (Thr-Glu-Tyr); p38 (Thr-Gly-Tyr); and JNK (Thr-Pro-Tyr). MAPK activation is mediated by signal transduction in the conserved three-tiered kinase cascade: MAPKKKK (MAP4K or MKKKK or MAPKKK Kinase) activates the MAPKKK. The MAPKKKs then phosphorylates a dual-specificity protein kinase MAPKK, which in turn phosphorylates the MAPK. The dual specificity MAP kinase kinases (MAPKK or MKK) differ for each group of MAPK. The ERK MAP kinases are activated by the MKK1 and MKK2; the p38 MAP kinases are activated by MKK3, MKK4, and MKK6; and the JNK pathway is activated by MKK4 and MKK7. The ability of MAP kinase kinases (MKKs, or MEKs) to recognize their cognate MAPKs is facilitated by a short docking motif (the D-site) in the MKK N-terminus, which binds to a complementary region on the MAPK. MAPKs then recognize many of their targets using the same strategy, because many MAPK substrates also contain D-sites. The upstream signaling events in the TLR cascade that initiate and mediate the ERK signaling pathway remain unclear."
BMGC_PW1220,BMG_PW3673,,,"p38 mitogen-activated protein kinase (MAPK) belongs to a highly conserved family of serine/threonine protein kinases. The p38 MAPK-dependent signaling cascade is activated by pro-inflammatory or stressful stimuli such as ultraviolet radiation, oxidative injury, heat shock, cytokines, and other pro-inflammatory stimuli. p38 MAPK exists as four isoforms (alpha, beta, gamma, and delta). Of these, p38alpha and p38beta are ubiquitously expressed while p38gamma and p38delta are differentially expressed depending on tissue type. Each isoform is activated by upstream kinases including MAP kinase kinases (MKK) 3, 4, and 6, which in turn are phosphorylated by activated TAK1 at the typical Ser-Xaa-Ala-Xaa-Thr motif in their activation loops. Once p38 MAPK is phosphorylated it activates numerous downstream substrates, including MAPK-activated protein kinase-2 and 3 (MAPKAPK-2 or 3) and mitogen and stress-activated kinase-1/2 (MSK1/2). MAPKAPK-2/3 and MSK1/2 function to phosphorylate heat shock protein 27 (HSP27) and cAMP-response element binding protein transcriptional factor, respectively. Other transcription factors, including activating transcription factor 2, Elk, CHOP/GADD153, and myocyte enhancer factor 2, are known to be regulated by these kinases."
BMGC_PW1221,BMG_PW3674,,,"C-Jun NH2 terminal kinases (JNKs) are an evolutionarily conserved family of serine/threonine protein kinases, that belong to mitogen activated protein kinase family (MAPKs - also known as stress-activated protein kinases, SAPKs). The JNK pathway is activated by heat shock, or inflammatory cytokines, or UV radiation. The JNKs are encoded by at least three genes: JNK1/SAPK-gamma, JNK2/SAPK-alpha and JNK3/ SAPK-beta. The first two are ubiquitously expressed, whereas the JNK3 protein is found mainly in brain and to a lesser extent in heart and testes. As a result of alternative gene splicing all cells express distinct active forms of JNK from 46 to 55 kDa in size. Sequence alignment of these different products shows homologies of >80%. In spite of this similarity, the multiple JNK isoforms differ in their ability to bind and phosphorylate different target proteins, thus leading to the distinctive cellular processes: induction of apoptosis, or enhancment of cell survival, or proliferation. Activation of JNKs is mediated by activated TAK1 which phosphorylates two dual specificity enzymes MKK4 (MAPK kinase 4) and MKK7(MAPK kinase 7)."
BMGC_PW1222,BMG_PW3675,,,"Activator protein-1 (AP-1) is a collective term referring to a group of transcription factors that bind to promoters of target genes in a sequence-specific manner. AP-1 family consists of hetero- and homodimers of bZIP (basic region leucine zipper) proteins, mainly of Jun-Jun, Jun-Fos or Jun-ATF. AP-1 members are involved in the regulation of a number of cellular processes including cell growth, proliferation, survival, apoptosis, differentiation, cell migration. The ability of a single transcription factor to determine a cell fate critically depends on the relative abundance of AP-1 subunits, the composition of AP-1 dimers, the quality of stimulus, the cell type, the co-factor assembly. AP-1 activity is regulated on multiple levels; transcriptional, translational and post-translational control mechanisms contribute to the balanced production of AP-1 proteins and their functions. Briefly, regulation occurs through: effects on jun, fos, atf gene transcription and mRNA turnover. AP-1 protein members turnover. post-translational modifications of AP-1 proteins that modulate their transactivation potential (effect of protein kinases or phosphatases). interactions with other transcription factors that can either induce or interfere with AP-1 activity."
BMGC_PW1223,BMG_PW3676,,,"Butyrate Response Factor 1 (BRF1, ZFP36L1, not to be confused with transcription factor IIIB) binds AU-rich elements in the 3' region of mRNAs. After binding, BRF1 recruits exonucleases (XRN1 and the exosome) and decapping enzymes (DCP1a and DCP2) to hydrolyze the RNA. The ability of BRF1 to direct RNA degradation is controlled by phosphorylation of BRF1. Protein kinase B/AKT1 phosphorylates BRF1 at serines 92 and 203. Phosphorylated BRF1 can still bind RNA but is sequestered by binding 14-3-3 protein, preventing BRF1 from destabilizing RNA. BRF1 is also phosphorylated by MK2 at serines 54, 92, 203, and at an unknown site in the C-terminus. It is unknown if this particular phosphorylated form of BRF1 binds 14-3-3."
BMGC_PW1224,BMG_PW3677,,,"AUF1 (hnRNP D0) dimers bind U-rich regions of AU-rich elements (AREs) in the 3' untranslated regions of mRNAs. The binding causes AUF1 dimers to assemble into higher order tetrameric complexes. Diphosphorylated AUF1 bound to RNA recruits additional proteins, including eIF4G, polyA-binding protein, Hsp, Hsc70, Hsp27, NSEP-1, NSAP-1, and IMP-2 which target the mRNA and AUF1 for degradation. Unphosphorylated AUF1 is thought to be less able to recruit additional proteins. AUF1 also interacts directly or indirectly with HuR and the RNA-induced silencing complex (RISC). AUF1 complexed with RNA and other proteins is ubiquitinated and targeted for destruction by the proteasome while the bound mRNA is degraded. Inhibition of ubiquitin addition to AUF1 blocks mRNA degradation. The mechanism by which ubiquitin-dependent proteolysis is coupled to mRNA degradation is unknown. At least 4 isoforms of AUF1 exist: p45 (45 kDa) contains all exons, p42 lacks exon 2, p40 lacks exon 7, and p37 lacks exons 2 and 7. The presence of exon 7 in p42 and p45 seems to block ubiquitination while the absence of exon 7 (p37 and p40) targets AUF1 for ubiquitination and destabilizes bound RNAs. Lack of exon 2 (p37 and p42) is associated with higher affinity for RNA and 14-3-3sigma (SFN). AUF1 binds and destabilizes mRNAs encoding Interleukin-1 beta (IL1B), Tumor Necrosis Factor alpha (TNFA), Cyclin-dependent kinase inhibitor 1 (CDNK1A, p21), Cyclin-D1 (CCND1), Granulocyte-macrophage colony stimulating factor (GM-CSF, CSF2), inducible Nitric oxide synthase (iNOS, NOS2), Proto-oncogene cFos (FOS), Myc proto-oncogene (MYC), Apoptosis regulator Bcl-2 (BCL2)."
BMGC_PW1225,BMG_PW3678,,,"Tristetraproline (TTP) binds RNAs that contain AU-rich elements and recruits enzymes that degrade RNA. TTP interacts with the exosome (3' to 5' exonuclease), XRN1 (5' to 3' exonuclease), and the decapping enzymes DCP1 and DCP2a. The activity of TTP is regulated by phosphorylation. MK2 phosphorylates TTP, which then binds 14-3-3.The interaction with 14-3-3 prevents phosphorylated TTP from entering stress granules and stabilizes mRNA bound by phosphorylated TTP. Tristetraproline is known to bind AU-rich elements in the following mRNAs: Tumor necrosis factor alpha (TNFA), Granulocyte-macrophage colony stimulating factor (CSF2, GM-CSF), Interleukin-2 (IL-2), and Proto-oncogene C-FOS (FOS, c-fos). Mice deficient in TTP exhibit arthritis, weight loss, skin lesions, autoimmunity, and myeloid hyperplasia."
BMGC_PW1226,BMG_PW3679,,,"HuR (ELAVL1) is a ubiquitous protein that binds AU-rich elements in mRNAs and acts to stabilize the mRNAs. HuR activity is controlled by phosphorylation, with PKC alpha and PCK delta enhancing the ability of HuR to bind and stabilize mRNAs. Binding of mRNAs occurs in the nucleus and HuR then interacts with the CRM1 export pathway to transfer the mRNA to the cytoplasm. The mechanism by which HuR shields the mRNA from degradation is unknown. HuR also regulates translation of some mRNAs, in some cases repressing translation and in some cases enhancing translation of bound mRNAs by recruiting them to polysomes. HuR binds and regulates mRNAs encoding Cyclooxygenase-2 (COX2, PTGS2), Cyclin A (CCNA, CCNA2), Cyclin D1 (CCND1), Cyclin B1 (CCNB1), CD83 antigen (CD83), and proto-oncogene c-Fos (FOS). HuR is a member of a family of proteins that also contains HuD (ELAVL4), HuB (ELAVL2), and HuC (ELAVL3). HuB, HuC, and HuD are specifically expressed in neural tissue. HuR participates in apoptosis. During lethal stress HuR becomes mostly cytoplasmic and is a target of Caspase-3 and Caspase-7. The cleavage products of HuR in turn promote apoptosis."
BMGC_PW1227,BMG_PW3680,,,"RNA elements rich in adenine and uracil residues (AU-rich elements) bind specific proteins which either target the RNA for degradation or, more rarely, stabilize the RNA. The activity of the AU-element binding proteins is regulated, usually by phosphorylation but also by subcellular localization."
BMGC_PW1228,BMG_PW3681,,,KSRP binds to AU-rich sequences in the 3' untranslated regions of mRNAs. KSRP causes the bound mRNA to be targeted for hydrolysis by recruiting exonucleases and decapping enzymes. The activity of KSRP is regulated by phosphorylation. Protein kinase B/Akt phosphorylates KSRP at serine193. The phosphorylation inhibits the ability of KSRP to destabilize mRNA. KSRP phosphorylated at serine193 binds 14-3-3zeta (YWHAZ) which causes KSRP to be retained in the nucleus.
BMGC_PW1229,BMG_PW3682,,,Kainate receptors are either Ca2+ permeable or impermeable depending on the composition of the receptor and the editing status of subunits GluR5 and GluR6 (GRIK1 and 2).
BMGC_PW1230,BMG_PW3684,,,"Kainate receptors that are assembled with subunits GRIK1-5, are Ca2+ permeable if GRIK1 and GRIK2 are not edited at the Q/R or other sites. These channels permit Ca2+ upon activation by glutamate or other agonists."
BMGC_PW1231,BMG_PW3685,,,Kainate receptors are found both in the presynaptc terminals and the postsynaptic neurons. Kainate receptor activation could lead to either ionotropic activity (influx of Ca2+ or Na+ and K+) in the postsynaptic neuron or coupling of the receptor with G proteins in the presynaptic and the postsynaptic neurons. Kainate receptors are tetramers made from subunits GRIK1-5 or GluR5-7 and KA1-2. Activation of kainate receptors made from GRIK1 or KA2 release Ca2+ from the intracellular stores in a G protein-dependent manner. The G protein involved in this process is sensitive to pertussis toxin.
BMGC_PW1232,BMG_PW3686,,,"Pluripotent stem cells are undifferentiated cells posessing an abbreviated cell cycle (reviewed in Stein et al. 2012), a characteristic profile of gene expression (Rao et al. 2004, Kim et al. 2006, Player et al. 2006, Wang et al 2006 using mouse, International Stem Cell Initiative 2007, Assou et al. 2007, Assou et al. 2009, Ding et al. 2012 using mouse), and the ability to self-renew and generate all cell types of the body except extraembryonic lineages (Marti et al. 2013, reviewed in Romeo et al. 2012). They are a major cell type in the inner cell mass of the early embryo in vivo, and cells with the same properties, induced pluripotent stem cells, can be generated in vitro from differentiated adult cells by overexpression of a set of transcription factor genes (Takahashi and Yamanaka 2006, Takahashi et al. 2007, Yu et al. 2007, Jaenisch and Young 2008, Stein et al. 2012, reviewed in Dejosez and Zwaka 2012). Pluripotency is maintained by a self-reinforcing loop of transcription factors (Boyer et al. 2005, Rao et al. 2006, Matoba et al. 2006, Player et al. 2006, Babaie et al. 2007, Sun et al. 2008, Assou et al. 2009, reviewed in Kashyap et al. 2009, reviewed in Dejosez and Zwaka 2012). In vivo, initiation of pluripotency may depend on maternal factors transmitted through the oocyte (Assou et al. 2009) and on DNA demethylation in the zygote (recently reviewed in Seisenberger et al. 2013) and hypoxia experienced by the blastocyst in the reproductive tract before implantation (Forristal et al. 2010, reviewed in Mohyeldin et al. 2010). In vitro, induced pluripotency may initiate with demethylation and activation of the promoters of POU5F1 (OCT4) and NANOG (Bhutani et al. 2010). Hypoxia also significantly enhances conversion to pluripotent stem cells (Yoshida et al. 2009). POU5F1 and NANOG, together with SOX2, encode central factors in pluripotency and activate their own transcription (Boyer et al 2005, Babaie et al. 2007, Yu et al. 2007, Takahashi et al. 2007). The autoactivation loop maintains expression of POU5F1, NANOG, and SOX2 at high levels in stem cells and, in turn, complexes containing various combinations of these factors (Remenyi et al. 2003, Lam et al. 2012) activate the expression of a group of genes whose products are associated with rapid cell proliferation and repress the expression of a group of genes whose products are associated with cell differentiation (Boyer et al. 2005, Matoba et al. 2006, Babaie et al. 2007, Chavez et al. 2009, Forristal et al. 2010, Guenther 2011). Comparisons between human and mouse embryonic stem cells must be made with caution and for this reason inferences from mouse have been used sparingly in this module. Human ESCs more closely resemble mouse epiblast stem cells in having inactivated X chromosomes, flattened morphology, and intolerance to passaging as single cells (Hanna et al. 2010). Molecularly, human ESCs differ from mouse ESCs in being maintained by FGF and Activin/Nodal/TGFbeta signaling rather than by LIF and canonical Wnt signaling (Greber et al. 2010, reviewed in Katoh 2011). In human ESCs POU5F1 binds and directly activates the FGF2 gene, however Pou5f1 does not activate Fgf2 in mouse ESCs (reviewed in De Los Angeles et al. 2012). Differences in expression patterns of KLF2, KLF4, KLF5, ESRRB, FOXD3, SOCS3, LIN28, NODAL were observed between human and mouse ESCs (Cai et al. 2010) as were differences in expression of EOMES, ARNT and several other genes (Ginis et al.2004)."
BMGC_PW1233,BMG_PW3687,,,"Mitotic G2 (gap 2) phase is the second growth phase during eukaryotic mitotic cell cycle. G2 encompasses the interval between the completion of DNA synthesis and the beginning of mitosis. During G2, the cytoplasmic content of the cell increases. At G2/M transition, duplicated centrosomes mature and separate and CDK1:cyclin B complexes become active, setting the stage for spindle assembly and chromosome condensation that occur in the prophase of mitosis (O'Farrell 2001, Bruinsma et al. 2012, Jiang et al. 2014)."
BMGC_PW1234,BMG_PW3688,,,Regulation of mitotic cell cycle currently covers APC/C-mediated degradation of cell cycle proteins.
BMGC_PW1235,BMG_PW3689,,,"Mitotic G1-G1/S phase involves G1 phase of the mitotic interphase and G1/S transition, when a cell commits to DNA replication and divison genetic and cellular material to two daughter cells. During early G1, cells can enter a quiescent G0 state. In quiescent cells, the evolutionarily conserved DREAM complex, consisting of the pocket protein family member p130 (RBL2), bound to E2F4 or E2F5, and the MuvB complex, represses transcription of cell cycle genes (reviewed by Sadasivam and DeCaprio 2013). During early G1 phase in actively cycling cells, transcription of cell cycle genes is repressed by another pocket protein family member, p107 (RBL1), which forms a complex with E2F4 (Ferreira et al. 1998, Cobrinik 2005). RB1 tumor suppressor, the product of the retinoblastoma susceptibility gene, is the third member of the pocket protein family. RB1 binds to E2F transcription factors E2F1, E2F2 and E2F3 and inhibits their transcriptional activity, resulting in prevention of G1/S transition (Chellappan et al. 1991, Bagchi et al. 1991, Chittenden et al. 1991, Lees et al. 1993, Hiebert 1993, Wu et al. 2001). Once RB1 is phosphorylated on serine residue S795 by Cyclin D:CDK4/6 complexes, it can no longer associate with and inhibit E2F1-3. Thus, CDK4/6-mediated phosphorylation of RB1 leads to transcriptional activation of E2F1-3 target genes needed for the S phase of the cell cycle (Connell-Crowley et al. 1997). CDK2, in complex with cyclin E, contributes to RB1 inactivation and also activates proteins needed for the initiation of DNA replication (Zhang 2007). Expression of D type cyclins is regulated by extracellular mitogens (Cheng et al. 1998, Depoortere et al. 1998). Catalytic activities of CDK4/6 and CDK2 are controlled by CDK inhibitors of the INK4 family (Serrano et al. 1993, Hannon and Beach 1994, Guan et al. 1994, Guan et al. 1996, Parry et al. 1995) and the Cip/Kip family, respectively."
BMGC_PW1236,BMG_PW3695,,,"Thrombin activates proteinase activated receptors (PARs) that signal through heterotrimeric G proteins of the G12/13 and Gq families, thereby connecting to a host of intracellular signaling pathways. Thrombin activates PARs by cleaving an N-terminal peptide that then binds to the body of the receptor to effect transmembrane signaling. Intermolecular ligation of one PAR molecule by another can occur but is less efficient than self-ligation. A synthetic peptide of sequence SFLLRN, the first six amino acids of the new N-terminus generated when thrombin cleaves PAR1, can activate PAR1 independent of protease and receptor cleavage. PARs are key to platelet activation. Four PARs have been identified, of which PARs 1 ,3 and 4 are substrates for thrombin. In humans PAR 1 is the predominant thrombin receptor followed by PAR4 which is less responsive to thrombin. PAR 3 is not considered important for human platelet responses as it is minimally expressed, though this is not the case for mouse. PAR2 is not expressed in platelets. In mouse platelets, Gq is necessary for platelet secretion and aggregation in response to thrombin but is not necessary for thrombin-triggered shape change. G13 appears to contribute to platelet aggregation as well as shape change in response to low concentrations of thrombin but to be unnecessary at higher agonist concentrations; G12 appears to be dispensable for thrombin signaling in platelets. G alpha (q) activates phospholipase C beta thereby triggering phosphoinositide hydrolysis, calcium mobilization and protein kinase C activation. This provides a path to calcium-regulated kinases and phosphatases, GEFs, MAP kinase cassettes and other proteins that mediate cellular responses ranging from granule secretion, integrin activation, and aggregation in platelets. Gbeta:gamma subunits can activate phosphoinositide-3 kinase and other lipid modifying enzymes, protein kinases, and channels. PAR1 activation indirectly leads to activation of cell surface 'sheddases' that liberate ligands for receptor tyrosine kinases, providing a link between thrombin and receptor tyrosine kinases involved in cell growth and differentiation. The pleiotrophic effects of PAR activation are consistent with many of thrombin's diverse actions on cells."
BMGC_PW1237,BMG_PW3696,,,"SUMOylation of RNA-binding proteins (Li et al. 2004, reviewed in Filosa et al. 2013) alters their interactions with nucleic acids and with proteins. Whereas SUMOylation of HNRNPC decreases its affinity for nucleic acid (ssDNA), SUMOylation of NOP58 is required for binding of snoRNAs. SUMOylation of HNRNPK is required for its coactivation of TP53-dependent transcription."
BMGC_PW1238,BMG_PW3698,,,"One of the hallmarks of the Planar Cell Polarity pathway is the asymmetric distribution of proteins on opposite membranes of a single cell. In Drosophila, Stbm and Pk (homologues to the human VANGL1/2 and PRICKLE1/2/3) colocalize opposite Fz, Dsh and Dgo (FZD, DVL, and ANKRD6, respectively). The two complexes antagonize each other, with Fz:Dsh:Dgo acting to promote signaling downstream of Dsh, while the Stbm:Pk complex restricts this signaling (reviewed in Seifert and Mlodzik, 2007). Asymmetric localization of some PCP proteins is also seen in vertebrates (Montcouquiol et al, 2003, 2006; Wang et al, 2006, Narimatsu et al, 2009) although the patterns of localization differ from that of flies. The details of how localization is established and how the asymmetrical distribution of proteins is translated into gross morphological processes remain to be fully elucidated."
BMGC_PW1239,BMG_PW3699,,,"The sliding clamp protein PCNA, Aurora-A, Aurora-B, Borealin, and various topoisomerases can be SUMOylated (reviewed in Wan et al. 2012). SUMOylation of PCNA appears to reduce formation of double-strand breaks and inappropriate recombination (reviewed in Watts 2006, Watts 2007, Dieckman et al. 2012, Gazy and Kupiec 2012). SUMOylation of Aurora-A, Aurora-B, and Borealin is necessary for proper chromosome segregation. SUMOylation of topoisomerases is observed in response to damage caused by inhibitors of topoisomerases."
BMGC_PW1240,BMG_PW3700,,,"AXIN is present in low concentrations in the cell and is considered to be the limiting component of the beta-catenin destruction complex in Xenopus; this may not be the case in mammalian cells, however (Lee et al, 2003; Tan et al, 2012). Cellular levels of AXIN are regulated in part through ubiquitin-mediated turnover. E3 ligases SMURF2 and RNF146 have both been shown to play a role in promoting the degradation of AXIN by the 26S proteasome (Kim and Jho, 2010; Callow et al, 2011; Zhang et al, 2011)."
BMGC_PW1241,BMG_PW3701,,,"DVL protein levels are regulated by both proteasomal and lysosomal degradation (reviewed in Gao and Chen, 2010). The E3 ligases HECF1, ITCH and KLHL12:CUL3 have all been shown to contribute to the polyubiquitination and subsequent degradation of DVL (Angers et al, 2006; Miyazaki et al, 2004; Wei et al, 2012). DVL stability is also regulated by its interaction with DACT1, which promotes degradation of DVL in the lysosome (Cheyette et al, 2002; Zhang et al, 2006)."
BMGC_PW1242,BMG_PW3702,,,"Upon stimulation with WNT ligand, AXIN and GSK3beta are recruited to the plasma membrane through interaction with DVL (Tamai et al, 2004; Mao et al, 2001; reviewed in He et al, 2004). Polymerization of membrane-associated DVL and GSK3beta- and CSNK1-mediated phosphorylation of LRP5/6 establish a feed-forward mechanism for enhanced membrane recruitment of AXIN upon WNT signaling (Tamai et al, 2004; Cong et al, 2004; Zeng et al, 2005; Bilic et al, 2007). In Xenopus oocytes, but not necessarily all sytems, AXIN is present in limiting concentrations and is considered rate limiting for the assembly of the destruction complex (Lee et al, 2003; Benchabane et al, 2008; Tan et al, 2012; reviewed in MacDonald et al, 2009). The recruitment of AXIN away from the destruction complex upon WNT stimulation effectively destabilizes the destruction complex and contributes to the accumulation of free beta-catenin (Kikuchi, 1999; Lee et al, 2003). AXIN association with the destruction complex is also regulated by phosphorylation. In the active destruction complex, AXIN is phosphorylated by GSK3beta; dephosphorylation by protein phosphatase 1 (PP1) or protein phosphatase 2A (PP2A) destabilizes the interaction of AXIN with the other components of the destruction complex and promotes its disassembly (Luo et al, 2007; Willert et al, 1999; Jho et al, 1999). Free AXIN is also subject to degradation by the 26S proteasome in a manner that depends on the poly-ADP-ribosylating enzymes tankyrase 1 and 2 (Huang et al, 2009)."
BMGC_PW1243,BMG_PW3703,,,"WNT responsiveness is influenced by expression levels of FZD and LRP proteins. Levels of these receptors at the cell surface are regulated in part by endocytosis, but the mechanisms are not fully elucidated (Garliardi et al, 2008). A number of recent studies have identified a role for ubiquitination in the localization and turnover of WNT receptors at the plasma membrane. ZNRF3 and RNF43 are E3 ligases that have been shown to ubiquitinate FZD proteins and promote their lysosomal degradation, while the deubiquitinating enzyme USP8 promotes recycling of the receptor back to the plasma membrane (Hao et al, 2012; Mukai et al, 2010). This balance of ubiquitination and deubiquitination is in turn regulated by the R-spondin (RSPO) proteins, agonists of WNT signaling which appear to act by downregulating ZNRF3 and RNF43, thus potentiating both canonical and non-canonical pathways (Hao et al, 2012; reviewed in Abo and Clevers, 2012; Fearon and Spence, 2012, Papartriantafyllou, 2012)."
BMGC_PW1244,BMG_PW3704,,,"In the absence of a WNT signal, many WNT target genes are repressed by Groucho/TLE. Groucho was initially identified in Drosophila, where it has been shown to interact with a variety of proteins to repress transcription (reviewed in Turki-Judeh and Courey, 2012). Groucho proteins, including the 4 human homologues (transducin-like enhancer of split (TLE) 1-4), do not bind DNA directly but instead are recruited to target genes through interaction with DNA-binding transcription factors including TCF/LEF (Brantjes et al, 2001; reviewed in Chen and Courey, 2000). Groucho proteins are believed to oligomerize in a manner that depends on an N-terminal glutamine-rich Q domain, and oligomerization may be important for function (Song et al, 2004; Pinto and Lobe, 1996). Groucho/TLE proteins affect levels of gene expression by interacting with the core transcriptional machinery as well as by modfiying chromatin structure through direct interaction with histones and recruitment of histone deacetylases, among other mechanisms (reviewed in Turki-Judeh and Courey, 2012). In addition to the four TLE proteins, human cells also include a truncated TLE-like protein called amino-terminal enhancer of split (AES) which contains the N-terminal Q domain but lacks much of the C-terminal sequence of TLE proteins, including the WD domain which is important for many protein-protein interactions. AES is believed to act as a dominant negative, since it is able to heter-oligomerize with full-length TLE proteins to form non-functional complexes (Brantjes et al, 2001; reviewed in Beagle and Johnson, 2010)."
BMGC_PW1245,BMG_PW3719,,,"The WNT signaling pathway has been linked with cancer ever since the identification of the first WNT as a gene activated by integration of mouse mammary tumor virus proviral DNA in virally-induced breast tumors (Nusse et al, 1984). The most well known example of aberrant WNT signaling in cancer is in colorectal cancer, where an activating mutation in a WNT pathway component is seen in 90% of sporadic cases. Inappropriate WNT pathway activation has also been implicated in most other solid human cancers but is not always associated with mutations in WNT pathway components (reviewed in Polakis, 2012). Both tumor suppressors and oncogenes have been identified in the so-called canonical WNT pathway, which regulates WNT-dependent transcription by promoting the degradation of beta-catenin in the absence of ligand (reviewed in Polakis, 2012). Loss-of-function mutations in the destruction complex components APC, Axin and AMER1 and gain-of-function mutations in beta-catenin itself cause constitutive signaling and are found in cancers of the intestine, kidney, liver and stomach, among others (Polakis, 1995; Segiditsas and Tomlinson, 2006; Peifer and Polakis, 2000; Laurent-Puig et al, 2001; Liu et al, 2000; Satoh et al, 2000; Major et al, 2007; Ruteshouser et al, 2008). WNTs and WNT pathway components are also frequently over- or under-expressed in various cancers, and these changes are correlated with epigenetic regulation of promoter activity. In some contexts, both the canonical and non-canonical WNT signaling, which governs processes such as cell polarity and morphogenesis, may also contribute to tumor formation by promoting cell migration, invasiveness and metastasis."
BMGC_PW1246,BMG_PW3725,,,"Chromatin organization refers to the composition and conformation of complexes between DNA, protein and RNA. It is determined by processes that result in the specification, formation or maintenance of the physical structure of eukaryotic chromatin. These processes include histone modification, DNA modification, and transcription. The modifications are bound by specific proteins that alter the conformation of chromatin."
BMGC_PW1247,BMG_PW3726,,,"AXIN1 and AXIN2 are critical scaffolding proteins of the beta-catenin destruction complex and make protein-protein interactions with several of the other complex components including APC, GSK3, CK1 and beta-catenin itself through specific domains (reviewed in Saito-Diaz et al, 2013). Because of its role in promoting the degradation of beta-catenin and thereby restricting WNT signaling, AXIN1 is regarded as a tumor suppressor; consistent with this, biallelic mutations in AXIN1 that abrogate its expression or result in the production of truncated proteins have been identified in some human cancers, notably in hepatocellular and colorectal carcinomas and medullobalstoma (Satoh et al, 2000; Taniguchi et al, 2002; Shimizu et al, 2002; Dahmen et al, 2001; reviewed in Salahshor and Woodgett, 2005)."
BMGC_PW1248,BMG_PW3727,,,"Mutations in exon 3 of the beta-catenin gene have been identified in a number of human cancers (Morin et al, 1997; Rubinfeld et al, 1997; reviewed in Polakis, 2000; Polakis, 2007). These mutations generally affect serine and threonine residues (S33, S37, T41, S45) that are the sites of phosphorylation by CK1 and GSK3; phosphorylation of these residues is required for the ubiquitin-mediated degradation of beta-catenin. Hence mutation of these phospho-acceptor sites stabilizes beta-catenin, allowing it to accumulate, translocate to the nucleus and activate WNT signaling through association with LEF1/TCF DNA binding partners (Hart et al, 1999; Peifer and Polakis, 2000; Laurent-Puig et al, 2001; reviewed in Saito-Diaz et al, 2013)."
BMGC_PW1249,BMG_PW3728,,,"APC is a large and central component of the destruction complex, which limits signaling in the absence of WNT ligand by promoting the ubiquitin-mediated degradation of beta-catenin. APC interacts with numerous components of the destruction complex, including AXINs (AXIN1 and AXIN2), GSK3s (GSK3alpha and GSK3beta), CK1, PP2A and beta-catenin, and these interactions are critical for the phosphorylation and degradation of beta-catenin (reviewed in Saito-Diaz et al, 2013). APC is itself the target of phosphorylation and K63 ubiquitination in the absence of WNT signaling and these modifications are required for its interactions with other components of the destruction complex (Tran and Polakis, 2012; Ha et al, 2004; reviewed in Stamos and Weis, 2013). More than 85% of sporadic and hereditary colorectal tumors carry loss-of-function mutations in APC. Most of the mutations are frameshifts and result in truncated proteins that lack the SAMP motifs and the 15 and 20 aa repeats that are implicated in binding AXIN and regulating beta-catenin binding and degradation (Miyoshi et al, 1992; Nagase and Nakamura, 1993; reviewed in Segditas and Tomlinson, 2006). Cancers expressing truncated APC have high levels of cytoplasmic beta-catenin and deregulated expression of WNT target genes (Korinek et al, 1997). Approximately 15% of the colorectal tumors with wild-type APC harbor phosphodegron mutations of beta-catenin; interestingly, mutations in APC and beta-catenin are mutually exclusive events. Similar to APC-mutant tumors, beta-catenin is stabilized in these tumors and constitutive WNT target activation is detected (Morin et al, 1997; reviewed in Polakis, 2000)."
BMGC_PW1250,BMG_PW3729,,,"AMER1/WTX is a component of the destruction complex that interacts directly with beta-catenin through its C-terminal half. Depletion of AMER1 through siRNA stabilizes cellular beta-catenin levels and increases transcriptional activity in a reporter assay consistent with a role for AMER1 in the degradation of beta-catenin (Major et al, 2007). Deletions of the entire AMER1 gene have been reported in Wilms tumor, as have nonsense and missense mutations that truncate the protein before the beta-catenin interaction domain. These mutations are predicted to stabilize beta-catenin and increase WNT signaling (reviewed in Saito-Diaz et al, 2013; Huff, 2011)."
BMGC_PW1251,BMG_PW3730,,,"An array of kinases catalyze the reversible phosphorylation of nucleotide monophosphates to form nucleotide diphosphates and triphosphates. Nucleoside monophosphate kinases catalyze the reversible phosphorylation of nucleoside and deoxynucleoside 5'-monophosphates to form the corresponding nucleoside 5'-diphosphates. Most appear to have restricted specificities for nucleoside monophosphates, and to use ATP preferentially (Van Rompay et al. 2000; Anderson 1973; Noda 1973). The total number of human enzymes that catalyze these reactions in vivo is not clear. In six cases, a well-defined biochemical activity has been associated with a purified protein, and these are annotated here. However, additional nucleoside monophosphate kinase-like human proteins have been identified in molecular cloning studies whose enzymatic activities are unknown, and several distinctive nucleoside monophosphate kinase activities detected in cell extracts, e.g., a GTP-requiring adenylate kinase activity (Wilson et al. 1976) and one or more guanylate kinase activities (Jamil et al. 1975) have not been unambiguously associated with specific human proteins. The nucleoside monophosphates against which each of the six well-characterized enzymes is active is shown in the table (Van Rompay et al. 2000). All six efficiently use ATP as a phosphate donor, but have some activity with other nucleoside triphosphates as well in vitro. The high concentrations of ATP relative to other nucleoside triphosphates in vivo makes it the likely major phosphate donor in these reactions under most conditions. All of these phosphorylation reactions are freely reversible in vitro when carried out with purified enzymes and substrates, having equilibrium constants near 1. In vivo, high ratios of ATP to ADP are likely to favor the forward direction of these reactions, i.e., the conversion of (d)NMP and ATP to (d)NDP and ADP. At the same time, the reversibility of the reactions and the overlapping substrate specificities of the enzymes raises the possibility that this group of reactions can buffer the intracellular nucleotide pool and regulate the relative concentrations of individual nucleotides in the pool: if any one molecule builds up to unusually high levels, multiple routes appear to be open not only to dispose of it but to use it to increase the supply of less abundant nucleotides. Ribonucleotide reductase catalyzes the synthesis of deoxyribonucleotide diphosphates from ribonucleotide diphosphates."
BMGC_PW1252,BMG_PW3731,,,Kainate receptors in the presynaptic neuron are involved in modulating the release of neurotransmitters like glutamate and gamma amino butyric acid (GABA). This activity of Kainate receptors is independent of ionic fluxes through the channel. Homomeric kainate receptors containing GRIK3 are shown to be involved in this process. Kainate receptors in these neurons bind G-protein coupled receptors that activate phospholipase C which eventually triggers the release of Ca2+ from the intracellular stores. The released Ca2+ further initiates the fusion and release of vesicles containing the neurotransmitter.
BMGC_PW1253,BMG_PW3732,,,"There are more than 800 G-protein coupled receptor (GPCRs) in the human genome, making it the largest receptor superfamily. GPCRs are also the largest class of drug targets, involved in virtually all physiological processes (Frederiksson 2003). GPCRs are receptors for a diverse range of ligands from large proteins to photons (Kristiansen et al. 2004) and have an equal diversity of ligand-binding mechanisms (Gether et al. 2002). Classical GPCR signaling involves signal transduction via heterotrimeric G-proteins, though G-protein independent mechanisms have been reported. Rhodopsin-like receptors (class A/1) are by far the largest group of GPCRs and the best studied, though a large proportion of the functional and structural studies have focused on a very few members; many remain functionally uncharacterized. This large family can be subdivided into at least 19 subfamilies (Subfamily A1-19) based on phylogenetic analysis (Joost & Methner 2002). Family A includes receptors for a wide variety of ligands including hormones, light and neurotransmitters, encompassing a wide range of functions including many autocrine, paracrine and endocrine processes. The secretin-like family B/2 GPCRs includes receptors for many hormone-like peptides, such as secretin, calcitonin, parathyroid hormone/parathyroid hormone-related peptides and vasoactive intestinal peptide, which activate adenylyl cyclase and the phosphatidyl-inositol-calcium pathway (Harmar 2001). The class C/3 GPCRs include the metabotropic glutamate receptors and taste receptors (Brauner-Osborne et al. 2007). All have a large extracellular N-terminus that structurally resembles a clamshell and has an important role in ligand binding."
BMGC_PW1254,BMG_PW3733,,,"The family of UDP GalNAc:polypeptide N acetylgalactosaminyltransferases (GalNAc transferases, GALNTs) carry out the addition of N acetylgalactosamine (GalNAc) on serine, threonine or possibly tyrosine residues on a wide variety of proteins, most commonly associated with mucins. This is the initial reaction in the biosynthesis of GalNAc-type O linked oligosaccharides (Wandall et al. 1997). This reaction takes place in the Golgi apparatus (Rottger et al. 1998). There are 20 known members of the GALNT family, 15 of which have been characterised and 5 candidate members which are thought to belong to this family based on sequence similarity (Bennett et al. 2012). The GALNT-family is classified as belonging to CAZy family GT27. Defects in one of the GALNT family genes, GALNT3 (MIM:601756), can cause familial hyperphosphatemic tumoral calcinosis (HFTC; MIM:211900). HFTC is a rare autosomal recessive severe metabolic disorder characterised by the progressive deposition of calcium phosphate crystals in the skin, soft tissues and sometimes bone (Chefetz et al. 2005). The biochemical observation is hyperphosphatemia, caused by increased renal absorption of phosphate (Chefetz et al. 2005, Ichikawa et al. 2005). Some patients manifest recurrent, transient, painful swellings of the long bones with radiological evidence of periosteal reaction and cortical hyperostosis (Frishberg et al. 2005)."
BMGC_PW1255,BMG_PW3737,,,"The Fringe family (CAZy family GT31) of glycosyltransferases in mammals includes LFNG (lunatic fringe; MIM:602576), MFNG (manic fringe; MIM:602577) and RFNG (radical fringe; MIM:602578). Fringe enzymes function in the Golgi apparatus where they initiate the elongation of O-linked fucose on fucosylated peptides by the addition of a beta 1,3 N-acetylglucosaminyl group (GlcNAc) (Moloney et al. 2000). Fringe enzymes elongate conserved O fucosyl residues conjugated to EGF repeats of NOTCH, modulating NOTCH activity (Cohen et al. 1997, Johnston et al. 1997) by decreasing the affinity of NOTCH extracellular domain for JAG ligands (Bruckner et al. 2000). The spondylocostal dysostoses (SCDs) are a group of disorders that arise during embryonic development by a disruption of somitogenesis. The Notch signalling pathway is essential for somitogenesis, the precursors of vertebra and associated musculature. Defects in one of the Fringe enzymes, beta-1,3-N-acetylglucosaminyltransferase lunatic fringe (LFNG), can cause spondylocostal dysostosis, autosomal recessive 3 (SCDO3, MIM:609813), a condition of variable severity associated with vertebral and rib segmentation defects (Sparrow et al. 2006)."
BMGC_PW1256,BMG_PW3738,,,"Glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1; MIM:610555) mediates the transfer of Galactose (Gal) from UDP-galactose to single O-linked GalNAc residues (Tn antigens) to form Core 1 structures on glycoproteins. C1GALT1 is active when in complex with the molecular chaperone C1GALT1C1 (aka COSMC; MIM:300611) which assists the folding and/or stability of C1GALT1. Defects in C1GALT1C1 causes somatic Tn polyagglutination syndrome (TNPS; MIM:300622), characterised by the polyagglutination of erythrocytes by naturally occurring anti-Tn antibodies following exposure of the Tn antigen on their surface. Defects in C1GALT1C1 render C1GALT1 inactive and results in the accumulation of the incompletely glycosylated Tn antigen. The Tn antigen is tumour-associated, found in a majority of human carcinomas, and is not normally expressed in peripheral tissues or blood cells (Crew et al. 2008, Ju et al. 2014). C1GALT1 and C1GALT1C1 belong to the CAZy family GT31 (www.cazy.org)."
BMGC_PW1257,BMG_PW3740,,,"Human beta-1,3-glucosyltransferase like protein (B3GALTL, HGNC Approved Gene Symbol: B3GLCT; MIM:610308; CAZy family GT31), localised on the ER membrane, glucosylates O-fucosylated proteins. The resultant glc-beta-1,3-fuc disaccharide modification on thrombospondin type 1 repeat (TSR1) domain-containing proteins is thought to assist in the secretion of many of these proteins from the ER lumen, and mediate an ER quality-control mechanism of folded TSRs (Vasudevan et al. 2015). Defects in B3GALTL can cause Peters plus syndrome (PpS; MIM:261540), an autosomal recessive disorder characterised by anterior eye chamber defects, short stature, delay in growth and mental developmental and cleft lip and/or palate (Heinonen & Maki 2009)."
BMGC_PW1258,BMG_PW3741,,,"The family of UDP GalNAc:polypeptide N acetylgalactosaminyltransferases (GalNAc transferases, GALNTs) carry out the addition of N acetylgalactosamine on serine, threonine or possibly tyrosine residues on a wide variety of proteins, and most commonly associated with mucins (Wandall et al. 1997). This reaction takes place in the Golgi apparatus (Rottger et al. 1998). There are 20 known members of the GALNT family, 15 of which have been characterised and 5 candidate members which are thought to belong to this family based on sequence similarity (Bennett et al. 2012). The GALNT-family is classified as belonging to CAZy family GT27. Defects in one of the GALNT family, GALNT12 (Guo et al. 2002) (MIM: 610290) can result in decreased glycosylation of mucins, mainly expressed in the digestive organs such as the stomach, small intestine and colon, and may play a role in colorectal cancer 1 (CRCS1; MIM:608812). CRCS1 is a complex disease characterised by malignant lesions arising from the inner walls of the colon and rectum (Guda et al. 2009, Clarke et al. 2012)."
BMGC_PW1259,BMG_PW3742,,,"WNT5A induces internalization of FZD4 in a manner that depends upon PKC-mediated phosphorylation of DVL2. Uptake of FZD4 appears to occur in a clathrin, AP-2 and ARBB2-dependent mannner (Chen et al, 2003; Yu et al, 2007; Yu et al, 2010)."
BMGC_PW1260,BMG_PW3743,,,"Internalization of FZD2, FZD5 and ROR2 after WNT5A binding is thought to occur in a clathrin-dependent manner and is required for the activation of RAC signaling (Kurayoshi et al, 2007; Sato et al, 2010; Hanaki et al, 2012; Yamamoto et al, 2009)."
BMGC_PW1261,BMG_PW3744,,,"O-glycosylation is an important post-translational modification (PTM) required for correct functioning of many proteins (Van den Steen et al. 1998, Moremen et al. 2012). The O-glycosylation of proteins containing thrombospondin type 1 repeat (TSR) domains and O-glycosylation of mucins are currently described here."
BMGC_PW1262,BMG_PW3745,,,"The O-fucosylation of proteins containing thrombospondin type 1 repeat (TSR) domains is an important PTM, regulating many biological processes such as Notch signalling, inflammation, wound healing, angiogenesis amd neoplasia (Adams & Tucker 2000, Moremen et al. 2012). Fucose addition is carried out by two protein fucosyltransferases, POFUT1 and 2. Only POFUT2 recognises the consensus sequence CSXS/TCG found in TSR1 domains and the fucosyl residue is attached to the hydroxyl group of conserved serine (S) or threonine (T) residues within the consensus sequence. The modification was first demonstrated on thrombospondin 1, found in platelets and the ECM (Hofsteenge et al. 2001, Luo et al. 2006). The resulting O-fucosyl-protein is subsequently a substrate for beta-1,3-glucosyltransferase-like protein (B3GALTL), which adds a glucosyl moiety to form the rare disaccharide modification Glc-beta-1,3-Fuc. More than 60 human proteins contain TSR1 domains, The disaccharide modification has been demonstrated on a small number of these TSR1 domain-containing proteins such as thrombospondin 1 (Hofsteenge et al. 2001, Luo et al. 2006), properdin (Gonzalez de Peredo et al. 2002) and F-spondin (Gonzalez de Peredo et al. 2002). The ADAMTS (a disintegrin-like and metalloprotease domain with thrombospondin type-1 repeats) superfamily consists of 19 secreted metalloproteases (ADAMTS proteases) and at lease five ADAMTS-like proteins in humans. Five members of the ADAMTS superfamily have also had experimental confirmation of the disaccharide modification. Examples are ADAMTS13 (Ricketts et al. 2007) and ADAMTSL1 (Wang et al. 2007). In the two reactions described here, the TSR1 domain-containing proteins with similarity to the experimentally confirmed ones are included as putative substrates."
BMGC_PW1263,BMG_PW3746,,,"This is the process of selective removal of damaged mitochondria by autophagosomes and subsequent catabolism by lysosomes. In healthy mitochondria, PTEN-induced putative kinase 1 (PINK1) is imported to the inner mitochondrial membrane, presumably through the TOM/TIM complex. The TIM complex associated protease, mitochondrial MPP, cleaves PINK1 mitochondrial targeting sequence (MTS). PINK1 may be cleaved by the inner membrane presenilin-associated rhomboid-like protease (PARL) and ultimately proteolytically degraded. Loss of membrane potential in damaged mitochondria prevents the import of PINK1 which accumulates on the mitochondrial outer membrane (MOM) of the defective mitochondria. Activation of PINK1 at MOM is achieved via dimerization-mediated trans-autophosphorylation of PINK1 at multiple sites including S228 and S402 (Okatsu K et al., 2012, 2013; Aerts L et al., 2015; Rasool S et al., 2018, 2022; Gan ZY et al., 2022). Activated PINK1 phosphorylates S65 of ubiquitin (Ub) on MOM proteins which leads to increased recruitment of the E3 ubiquitin ligase Parkin (PRKN) to damaged mitochondria (Koyano F et al., 2014; Shiba-Fukushima K et al., 2014; Ordureau A et al., 2015). Activated PINK1 also phosphorylates PRKN at S65 in the N-terminal Ub-like domain inducing the E3 ligase activity of PRKN (Kondapalli et al., 2012; Kazlauskaite A et al., 2015; Ordureau A et al., 2015). Activated PRKN promotes the ubiquitination of mitochondrial substrates including mitofusin 1 and 2 (MFN1, 2) and the voltage-dependent anion channel 1 and 3 (VDAC1, 3). The E3 ligase activity of PRKN generates Ub moieties for PINK1-mediated phosphorylation of Ub thus leading to a feedforward loop in the PINK1:PRKN pathway (Ordureau A et al., 2015; Sauve V et al., 2022). Ubiquitin chains on PRKN-ubiquitinated substrates recruit cargo receptors such as SQSTM1 (p62) and OPTN linking the ubiquitinated substrates to the microtubule-associated proteins 1A/1B light chain 3 (LC3, MAP1LC3) (Heo LM et al., 2015; Lazarou M et al., 2015). The recruitment of both MAP1LC3 (LC3) complexes and the autophagy proteins 5 and 12 (Atg5: Atg12) complex to the autophagosome membrane promotes autophagosome formation. The mitochondrion is engulfed after the isolation membrane grows to a sufficient size to engulf the mitochondrion. Once autophagic vesicle formation is complete, vesicle fusion with lysosomes occurs to form autophagolysosomes in which the lysosomal hydrolases (cathepsins and lipases) degrade the intra autophagosomal content. Cathepsin also degrades LC3 on the intra autophagosomal surface of the autophagic vesicle."
BMGC_PW1264,BMG_PW3747,,,"Bacillus anthracis bacteria target cells in an infected human through the action of three secreted bacterial proteins, lef (also known as LF, lethal factor), cya (also known as EF, edema factor), and pagA (also known as PA, protective antigen) (Turk 2007; Young and Collier 2007). lef is a protease that cleaves and inactivates many MAP2K (MAP kinase kinase, MEK) proteins (Duesbery et al. 1998; Vitale et al. 2000), disrupting MAP kinase signaling pathways. cya is an adenylate cyclase that mediates the constitutive production of cAMP (Leppla 1982), a molecule normally generated transiently in tightly regulated amounts in response to extracellular signals. Both lef and cya depend on pagA to enter their target cells, a strategy characteristic of bacterial binary toxins (Barth et al. 2004). pagA binds to the target cell receptors, is cleaved by furin or other cellular proteases, and thereupon forms an oligomer that exposes binding sites for lef and cya molecules (Young and Collier 2007). This complex is taken into the target cell by clathrin mediated endocytosis and delivered to endosomes. The low pH of the endosome causes the bacterial toxin complex to rearrange: the pagA oligomer forms a pore in the endosome membrane through which lef and cya molecules enter the target cell cytosol."
BMGC_PW1265,BMG_PW3748,,,"Receptor-interacting serine/threonine-kinase protein 1 (RIPK1) and RIPK3-dependent necrosis is called necroptosis or programmed necrosis. The kinase activities of RIPK1 and RIPK3 are essential for the necroptotic cell death in human, mouse cell lines and genetic mice models (Cho YS et al. 2009; He S et al. 2009, 2011; Zhang DW et al. 2009; McQuade T et al. 2013; Newton et al. 2014). The initiation of necroptosis can be stimulated by the same death ligands that activate extrinsic apoptotic signaling pathway, such as tumor necrosis factor (TNF) alpha, Fas ligand (FasL), and TRAIL (TNF-related apoptosis-inducing ligand) or toll like receptors 3 and 4 ligands (Holler N et al. 2000; He S et al. 2009; Feoktistova M et al. 2011; Voigt S et al. 2014). In contrast to apoptosis, necroptosis represents a form of cell death that is optimally induced when caspases are inhibited (Holler N et al. 2000; Hopkins-Donaldson S et al. 2000; Sawai H 2014). Specific inhibitors of caspase-independent necrosis, necrostatins, have recently been identified (Degterev A et al. 2005, 2008). Necrostatins have been shown to inhibit the kinase activity of RIPK1 (Degterev A et al. 2008). Importantly, cell death of apoptotic morphology can be shifted to a necrotic phenotype when caspase 8 activity is compromised, otherwise active caspase 8 blocks necroptosis by the proteolytic cleavage of RIPK1 and RIPK3 (Kalai M et al. 2002; Degterev A et al. 2008; Lin Y et al. 1999; Feng S et al. 2007). When caspase activity is inhibited under certain pathophysiological conditions or by pharmacological agents, deubiquitinated RIPK1 is engaged in physical and functional interactions with the cognate kinase RIPK3 leading to formation of necrosome, a necroptosis-inducing complex consisting of RIPK1 and RIPK3 (Sawai H 2013; Moquin DM et al. 2013; Kalai M et al. 2002; Cho YS et al. 2009, He S et al. 2009, Zhang DW et al. 2009). Within the necrosome RIPK1 and RIPK3 bind to each other through their RIP homotypic interaction motif (RHIM) domains. The RHIMs can facilitate RIPK1:RIPK3 oligomerization, allowing them to form amyloid-like fibrillar structures (Li J et al. 2012; Mompean M et al. 2018). RIPK3 in turn interacts with mixed lineage kinase domain-like protein (MLKL) (Sun L et al. 2012; Zhao J et al. 2012; Murphy JM et al. 2013; Chen W et al. 2013). The precise mechanism of MLKL activation by RIPK3 is incompletely understood and may vary across species (Davies KA et al. 2020). Mouse MLKL activation relies on transient engagement of RIPK3 to facilitate phosphorylation of the pseudokinase domain (Murphy JM et al. 2013; Petrie EJ et al. 2019a), while it appears that stable recruitment of human MLKL by necrosomal RIPK3 is an additional crucial step in human MLKL activation (Davies KA et al. 2018; Petrie EJ et al. 2018, 2019b). RIPK3-mediated phosphorylation is thought to initiate MLKL oligomerization, membrane translocation and membrane disruption (Sun L et al. 2012; Wang H et al. 2014; Petrie EJ et al. 2020; Samson AL et al. 2020). Studies in human cell lines suggest that upon induction of necroptosis MLKL shifts to the plasma membrane and membranous organelles such as mitochondria, lysosome, endosome and ER (Wang H et al. 2014), but it is trafficking via a Golgi-microtubule-actin-dependent mechanism that facilitates plasma membrane translocation, where membrane disruption causes death (Samson AL et al. 2020). The mechanisms of necroptosis regulation and execution downstream of MLKL remain elusive. The precise oligomeric form of MLKL that mediates plasma membrane disruption has been highly debated (Cai Z et al. 2014; Chen X et al. 2014; Dondelinger Y et al. 2014; Wang H et al. 2014; Petrie EJ et al. 2017, 2018; Samson AL et al. 2020 ). However, microscopy data revealed that MLKL assembles into higher molecular weight species upon cytoplasmic necrosomes within human cells, and upon phosphorylation by RIPK3, MLKL is trafficked to the plasma membrane (Samson AL et al. 2020). At the plasma membrane, phospho-MLKL forms heterogeneous higher order assemblies, which are thought to permeabilize cells, leading to release of DAMPs to invoke inflammatory responses. MLKL also exerts non-necroptotic functions such as regulation of endosomal trafficking or MLKL-induced activation of the NLRP3 inflammasome (Yoon S et al. 2017; Shlomovitz I et al. 2020; Yoon S et al. 2022). While RIPK1, RIPK3 and MLKL are the core signaling components in the necroptosis pathway, many additional molecules have been proposed to positively and negatively tune the signaling pathway. Currently, this picture is evolving rapidly as new modulators continue to be discovered. The Reactome module describes MLKL-mediated necroptotic events on the plasma membrane."
BMGC_PW1266,BMG_PW3749,,,"Necrosis has traditionally been considered as a passive, unregulated cell death. However, accumulating evidence suggests that necrosis, like apoptosis, can be executed by genetically controlled and highly regulated cellular process that is morphologically characterized by a loss of cell membrane integrity, intracellular organelles and/or the entire cell swelling (oncosis) (Rello S et al. 2005; Galluzzi L et al. 2007; Berghe TV et al. 2014; Ros U et al. 2020). The morphological hallmarks of the nectotic death have been associated with different forms of programmed cell death including (but not limited to) parthanatos, necroptosis, glutamate-induced oxytosis, ferroptosis, inflammasome-mediated necrosis etc. Each of them can be triggered under certain pathophysiological conditions. For example UV, ROS or alkylating agents may induce poly(ADP-ribose) polymerase 1 (PARP1) hyperactivation (parthanatos), while tumor necrosis factor (TNF) or toll like receptor ligands (LPS and dsRNA) can trigger necrosome-mediated necroptosis. The initiation events, e.g., PARP1 hyperactivation, necrosome formation, activation of NADPH oxidases, in turn trigger one or several common intracellular signals such as NAD+ and ATP-depletion, enhanced Ca2+ influx, dysregulation of the redox status, increased production of reactive oxygen species (ROS) and the activity of phospholipases. These signals affect cellular organelles and membranes leading to osmotic swelling, massive energy depletion, lipid peroxidation and the loss of lysosomal membrane integrity. Different mechanisms of permeabilization have emerged depending on the cell death form. Pore formation by gasdermins (GSDMs) is a hallmark of pyroptosis, while mixed lineage kinase domain-like (MLKL) protein facilitates membrane permeabilization in necroptosis, and phospholipid peroxidation leads to membrane damage in ferroptosis. This diverse repertoire of mechanisms leading to membrane permeabilization contributes to define the specific inflammatory and immunological outcome of each type of regulated necrosis. Regulated or programmed necrosis eventually leads to cell lysis and release of cytoplasmic content into the extracellular region that is often associated with a tissue damage resulting in an intense inflammatory response. The Reactome module describes necroptosis and pyroptosis."
BMGC_PW1267,BMG_PW3750,,,"Cell death triggered by extrinsic stimuli via death receptors or toll-like receptors (e.g., TLR3, TLR4) may result in either apoptosis or regulated necrosis (necroptosis) (Holler N et al. 2000; Kalai M et al. 2002; Kaiser WJ and Offermann MK 2005; Yang P et al. 2007). Caspase-8 (CASP8) is a cysteine protease, which functions as a key mediator for determining which form of cell death will occur (Kalai M et al. 2002). The proteolytic activity of a fully processed, heterotetrameric form of CASP8 in human and rodent cells is required for proapoptotic signaling and also for a cleavage of kinases RIPK1 and RIPK3, while at the same time preventing RIPK1/RIPK3-dependent regulated necrosis (Juo P et al. 1998; Lin Y et al. 1999; Holler N et al. 2000; Hopkins-Donaldson S et al. 2000). A blockage of CASP8 activity in the presence of caspase inhibitors such as Z-VAD-FMK (pan-caspase inhibitor), endogenous FLIP(S) or viral FLIP-like protein was found to switch signaling to necrotic cell death (Thome M et al. 1997; Kalai M et al. 2002; Feoktistova M et al. 2011; Sawai H 2013)."
BMGC_PW1268,BMG_PW3751,,,"The free radical nitric oxide (NO), produced by endothelial NO synthase (eNOS), is an important vasoactive substance in normal vascular biology and pathophysiology. It plays an important role in vascular functions such as vascular dilation and angiogenesis (Murohara et al. 1998, Ziche at al. 1997). NO has been reported to be a downstream mediator in the angiogenic response mediated by VEGF, but the mechanism by which NO promotes neovessel formation is not clear (Babaei & Stewart 2002). Persistent vasodilation and increase in vascular permeability in the existing vasculature is observed during the early steps of angiogenesis, suggesting that these hemodynamic changes are indispensable during an angiogenic processes. NO production by VEGF can occur either through the activation of PI3K or through a PLC-gamma dependent manner. Once activated both pathways converge on AKT phosphorylation of eNOS, releasing NO (Lin & Sessa 2006). VEGF also regulates vascular permeability by promoting VE-cadherin endocytosis at the cell surface through a VEGFR-2-Src-Vav2-Rac-PAK signalling axis."
BMGC_PW1269,BMG_PW3752,,,"VEGFR2 stimulates ERK not via GRB2-SOS-RAS, but via pY1175-dependent phosphorylation of PLC gamma and subsequent activation of PKCs. PKC plays an important mediatory role in the proliferative Ras/Raf/MEK/ERK pathway. PKC alpha can intersect the Ras/Raf/MEK/ERK cascade at the level of Ras (Clark et al. 2004) or downstream of Ras through direct phosphorylation of Raf (Kolch et al. 1993). VEGF stimulation leads to Ras activation in a Ras-guanine nucleotide exchange factor (GEF) independent mechanism. It rather relies on modulating the regulation of Ras-GTPase activating protein (GAP) than regulation of Ras-GEFS (Wu et al. 2003)."
BMGC_PW1270,BMG_PW3753,,,"About 2-6% of all cytosine residues and 70-80% of cytosine residues in CG dinucleotides in mammalian cells are methylated at the 5 position of the pyrimidine ring. The cytosine residues are methylated by DNA methyltransferases after DNA replication and can be demethylated by passive dilution during subsequent replication or by active modification of the 5-methylcytosine base. Cytosine demethylation is developmentally regulated: one wave of demethylation occurs in primordial germ cells and one wave occurs by active demethylation in the male pronucleus after fertilization. Some mechanisms of active demethylation remain controversial, however progressive oxidation of the methyl group of 5-methylcytosine followed by base excision by thymine DNA glycosylase (TDG) has been reproducibly demonstrated in vivo (reviewed in Wu and Zhang 2011, Franchini et al 2012, Cadet and Wagner 2013, Kohli and Zhang 2013, Ponnaluri et al. 2013, Rasmussen and Helin 2016). Ten-eleven translocation proteins TET1, TET2, and TET3 are dioxygenases that first oxidize 5-methylcytosine to 5-hydroxymethylcytosine (5-hmC) (Tahiliani et al. 2009, Ito et al. 2010), which is found in significant quantities and specific genomic locations in stem cells and neurons (Kinney and Pradhan 2013). TET proteins can further oxidize 5-hmC to 5-formylcytosine (5-fC) and then 5-carboxylcytosine (5-caC) (He et al. 2011, Ito et al. 2011). G:5-fC and G:5-caC base pairs are recognized by TDG, which excises the 5-fC or 5-caC and leaves an abasic site. TET1 in mouse is expressed in neurons and its expression depends on neuronal activity (Guo et al. 2011, Kaas et al. 2013, Zhang et al. 2013). TET1 is also found in embryonic stem cells (Ficz et al. 2011, Koh et al. 2011, Wu et al. 2011) and in primordial germ cells of mice, where it plays a role in erasure of imprinting (Yamaguchi et al. 2013). TET3 is expressed in oocytes and zygotes of mice and is required for demethylation in the male pronucleus (Gu et al. 2011, Iqbal et al. 2011). TET2 is the most highly expressed TET family protein in hemopoietic stem cells and appears to act as a tumor suppressor. TET2 is also expressed in embryonic stem cells (Koh et al. 2011)."
BMGC_PW1271,BMG_PW3754,,,"This section contains known transport and binding events that as of yet cannot be placed in exisiting pathways (Purves 2001, He et al. 2009, Rees et al. 2009)."
BMGC_PW1272,BMG_PW3755,,,"Transcription of rRNA genes is controlled by epigenetic activation and repression according to the metabolic requirements of the cell (reviewed in Percipalle and Farrants 2006, McStay and Grummt 2008, Goodfellow and Zomerdijk 2012, Grummt and Langst 2013). Depending on the growth state of the cell, about half of the approximately 400 rRNA genes are expressed and these have the modifications characteristic of active chromatin: unmethylated DNA and acetylated histones. Repressed genes generally have methylated DNA and histone H3 methylated at lysine-9. Regulators of activation include ERCC6 (CSB), histone acetylases such as KAT2B (PCAF), and the B-WICH complex. Dysregulation of RNA polymerase I transcription plays a role in disease (reviewed in Hannan et al. 2013). The B-WICH complex positively regulates rRNA expression by remodeling chromatin and recruiting histone acetyltransferases that modify histones to transcriptionally active states ERCC6 (CSB) and EHMT2(G9a) positively regulate rRNA expression by ERCC6 recruiting the histone methyltransferase EHMT2 (also known as G9a) which dimethylates histone H3 at lysine-9 within the transcribed regions of rRNA genes. ERCC6 (CSB) and KAT2B (PCAF) positively regulate rRNA expression by ERCC6 recruiting the histone acetyltransferase KAT2B to the promoter where KAT2B acetylates histone H4 at several lysine residues and histone H3 at lysine-9. The acetylated chromatin facilitates the assembly of RNA polymerase I initiation complex."
BMGC_PW1273,BMG_PW3756,,,"The B-WICH complex is a large 3 Mdalton complex containing SMARCA5 (SNF2H), BAZ1B (WSTF), ERCC6 (CSB), MYO1C (Nuclear myosin 1c), SF3B1, DEK, MYBBP1A, and DDX21 (Cavellan et al. 2006, Percipalle et al. 2006, Vintermist et al. 2001, Sarshad et al. 2013, Shen et al. 2013, reviewed in Percipalle and Farrants 2006). B-WICH is found at active rRNA genes as well as at 5S rRNA and 7SL RNA genes. B-WICH appears to remodel chromatin and recruit histone acetyltransferases that modify histones to transcriptionally active states."
BMGC_PW1274,BMG_PW3757,,,"Transcription of rRNA genes is controlled by epigenetic activation and repression (reviewed in McStay and Grummt 2008, Goodfellow and Zomerdijk 2012, Grummt and Langst 2013). About half of the roughly 400 rRNA genes are expressed and these have the modifications of active chromatin: unmethylated DNA and acetylated histones. Repressed genes generally have methylated DNA and histone H3 methylated at lysine-9. Regulators of repression include the eNoSC complex, SIRT1, and the NoRC complex. SIRT1 negatively regulates rRNA expression as a subunit of the eNoSC complex, which deacetylates histone H3 and dimethylates lysine-9 of histone H3 (H3K9me2). NoRC negatively regulates rRNA expression by shifting a nucleosome near the start of rRNA transcription into a more repressive location and recruiting Histone Deacetylase 1 and 2 (HDAC1, HDAC2) and DNA Methyltransferase 1 and 3b (DNMT1, DNMT3b)."
BMGC_PW1275,BMG_PW3758,,,"Botulinum toxin type D (botD) is only very rarely associated with human disease (Hatheway 1995) and a pathway by which it might enter the circulation from the human gut has not been described. Nevertheless, the toxin itself, a disulfide-bonded heavy chain (HC) - light chain (LC) heterodimer (“dichain”), is capable of binding to neurons by interactions with cell surface ganglioside (Kroken et al. 2011) and synaptic vesicle protein 2 (SV2) (Peng et al. 2011), the bound toxin can enter synaptic vesicles and release its LC moiety into the cytosol of targeted cells (Montal 2010), and the botD LC can cleave vesicle associated membrane proteins 1 and 2 (VAMP1 and 2) on the cytosolic face of the synaptic vesicle membrane (Schiavo et al. 1993; Yamasaki et al. 1994). These four events are annotated here."
BMGC_PW1276,BMG_PW3762,,,"Botulinum toxin type F (botF) is only very rarely associated with human disease (Hatheway 1995) and a pathway by which it might enter the circulation from the human gut has not been described. Nevertheless, the toxin itself, a disulfide-bonded heavy chain (HC) - light chain (LC) heterodimer (""dichain""), is capable of binding to neurons by interactions with cell-surface ganglioside and synaptic vesicle protein 2 (SV2) (Fu et al. 2009; Rummel et al. 2009), the bound toxin can enter synaptic vesicles and release its LC moiety into the cytosol of targeted cells (Montal 2010), and the botF LC can cleave vesicle-associated membrane proteins 1 and 2 (VAMP1 and 2) on the cytosolic face of the synaptic vesicle membrane (Yamasaki et al. 1994). These four events are annotated here."
BMGC_PW1277,BMG_PW3766,,,"Myogenesis, the formation of muscle tissue, is a complex process involving steps of cell proliferation mediated by growth factor signaling, cell differentiation, reorganization of cells to form myotubes, and cell fusion. Here, one regulatory feature of this process has been annotated, the signaling cascade initiated by CDO (cell-adhesion-molecule-related/downregulated by oncogenes) and associated co-receptors. CDO/Cdon is a type I transmembrane multifunctional co-receptor consisting of five immunoglobulin and three fibronectin type III (FNIII) repeats in the extracellular domain, and an intracellular domain with no identifiable motifs. It has been implicated in enhancing muscle differentiation in promyogenic cells. CDO exert its promyogenic effects as a component of multiprotein complexes that include the closely related factor Boc, the Ig superfamily receptor neogenin and its ligand netrin-3, and the adhesion molecules N- and M-cadherin. CDO modulates the Cdc42 and p38 mitogen-activated protein kinase (MAPK) pathways via a direct association with two scaffold-type proteins, JLP and Bnip-2, to regulate activities of myogenic bHLH factors and myogenic differentiation. CDO activates myogenic bHLH factors via enhanced heterodimer formation, most likely by inducing hyper-phosphorylation of E proteins. Myogenic basic helix-loop-helix (bHLH) proteins are master regulatory proteins that activate the transcription of many muscle-specific genes during myogenesis. These myogenic bHLH proteins also referred to as MyoD family includes four members, MyoD, myogenin, myf5 and MRF4. These myogenic factors dimerize with E-proteins such as E12/E47, ITF-2 and HEB to form heterodimeric complexes that bind to a conserved DNA sequence known as the E box, which is present in the promoters and enhancers of most muscle-specific genes. Myocyte enhancer binding factor 2 (MEF2), which is a member of the MADS box family, also plays an important role in muscle differentiation. MEF2 activates transcription by binding to the consensus sequence, called the MEF2-binding site, which is also found in the control regions of numerous muscle-specific genes. MEF2 and myogenic bHLH proteins synergistically activate expression of muscle-specific genes via protein-protein interactions between DNA-binding domains of these heterologous classes of transcription factors. Members of the MyoD and MEF2 family of transcription factors associate combinatorially to control myoblast specification, differentiation and proliferation."
BMGC_PW1278,BMG_PW3768,,,"After being synthesized in the ER membrane the 14-sugars lipid-linked oligosaccharide is co-translationally transferred to an unfolded protein, as described in the previous steps. After this point the N-glycan is progressively trimmed of the three glucoses and some of the mannoses before the protein is transported to the cis-Golgi. The role of these trimming reactions is that the N-glycan attached to an unfolded glycoprotein in the ER assume the role of 'tags' that direct the interactions of the glycoprotein with different elements that mediate its folding. The removal of the two outer glucoses leads to an N-glycan with only one glucose, which is a signal for the binding of either one of two chaperone proteins, calnexin (CNX) and calreticulin (CRT). These chaperones provide an environment where the protein can fold more easily. The interaction with these proteins is not transient and is terminated by the trimming of the last remaining glucose, after which the glycoprotein is released from CNX or CRT and directed to the ER Quality Control compartment (ERQC) if it still has folding defects, or transported to the Golgi if the folding is correct. The involvement of N-glycans in the folding quality control of proteins in the ER explains why this form of glycosylation is so important, and why defects in the enzymes involved in these reactions are frequently associated with congenital diseases. However, there are many unknown points in this process, as it is known that even proteins without N-glycosylation sites can be folded properly (Caramelo JJ and Parodi AJ, 2008)."
BMGC_PW1279,BMG_PW3769,,,"Methylation of cytosine is catalyzed by a family of DNA methyltransferases (DNMTs): DNMT1, DNMT3A, and DNMT3B transfer methyl groups from S-adenosylmethionine to cytosine, producing 5-methylcytosine and homocysteine (reviewed in Klose and Bird 2006, Ooi et al. 2009, Jurkowska et al. 2011, Moore et al. 2013). (DNMT2 appears to methylate RNA rather than DNA.) DNMT1, the first enzyme discovered, preferentially methylates hemimethylated CG motifs that are produced by replication (template strand methylated, synthesized strand unmethylated). Thus it maintains existing methylation through cell division. DNMT3A and DNMT3B catalyze de novo methylation at unmethylated sites that include both CG dinucleotides and non-CG motifs. DNA from adult humans contains about 0.76 to 1.00 mole percent 5-methylcytosine (Ehrlich et al. 1982, reviewed in Klose and Bird 2006, Ooi et al. 2009, Moore et al. 2013). Methylation of DNA occurs at cytosines that are mainly located in CG dinucleotides. CG dinucleotides are unevenly distributed in the genome. Promoter regions tend to have a high CG-content, forming so-called CG-islands (CGIs), while the CG-content in the remaining part of the genome is much lower. CGIs tend to be unmethylated, while the majority of CGs outside CGIs are methylated. Methylation in promoters and first exons tends to repress transcription while methylation in gene bodies (regions of genes downstream of the promoter and first exon) correlates with transcription (reviewed in Ehrlich and Lacey 2013, Kulis et al. 2013). Proteins such as MeCP2 and MBDs specifically bind 5-methylcytosine and may recruit other factors. Mammalian development has two major episodes of genome-wide demethylation and remethylation (reviewed in Zhou 2012, Guibert and Weber 2013, Hackett and Surani 2013, Dean 2014). In mice about 1 day after fertilization the paternal genome is actively demethylated by TET proteins together with thymine DNA glycosylase and the maternal genome is demethylated by passive dilution during replication, however methylation at imprinted sites is maintained. The genome has its lowest methylation level about 3.5 days post-fertilization. Remethylation occurs by 6.5 days post-fertilization. The second demethylation-remethylation event occurs in primordial germ cells of the developing embryo about 12.5 days post-fertilization. DNMT3A and DNMT3B, together with the non-catalytic DNMT3L, play major roles in the remethylation events (reviewed in Chen and Chan 2014). How the methyltransferases are directed to particular regions of the genome remains an area of active research. The mechanisms at each locus may differ in detail but a connection between histone modifications and DNA methylation has been observed (reviewed in Rose and Klose 2014)."
BMGC_PW1280,BMG_PW3770,,,"Diphtheria is a serious, often fatal human disease associated with damage to many tissues. Bacteria in infected individuals, however, are typically confined to the lining of the throat or to a skin lesion; systemic effects are due to the secretion of an exotoxin encoded by a lysogenic bacteriophage. The toxin is encoded as a single polypeptide but is cleaved by host furin-like proteases to yield an aminoterminal fragment A and a carboxyterminal fragment B, linked by a disulfide bond. Toxin cleavage can occur when it first contacts the target cell surface, as annotated here, or as late as the point at which fragment A is released into the cytosol. Fragment B mediates toxin uptake into target cell endocytic vesicles, where acidification promotes a conformational change enabling fragment B to form a channel in the vesicle membrane through which fragment A is extruded into the target cell cytosol. Cleavage of the inter-fragment disulfide bond frees DT fragment A, which catalyzes ADP ribosylation of the translation elongation factor 2 (EEF2) in a target cell, thereby blocking protein synthesis. Neither fragment is toxic to human cells by itself (Collier 1975; Pappenheim 1977; Murphy 2011)."
BMGC_PW1281,BMG_PW3771,,,The toxic effects of many bacteria on their human hosts are mediated by proteins released from the bacteria that enter human cells and disrupt critical cellular functions (Henkel et al. 2010). All of the ones annotated here share a bipartiite mechanism of host intoxication: one moiety binds target cells and mediates the delivery of the other part to the intracellular compartment where it can function as an enzyme to degrade or derivatize and inactivate critical target cell proteins or to activate constitutive synthesis of high levels of cAMP.
BMGC_PW1282,BMG_PW3773,,,"GSK3beta is subject to in-frame missplicing in CML stem cells resulting in the production of mutant protein that lacks the AXIN and FRAT binding domains. Cells containing this mutant GSK3beta show elevated levels of nuclear beta-catenin and enhanced TCF-dependent reporter activity (Jamieson et al, 2008; Abrahamsson et al, 2009)."
BMGC_PW1283,BMG_PW3776,,,"RNF43 and related protein ZNRF3 are E3 ubiquitin ligases that negatively regulate WNT signaling by downregulating FZD receptors at the cell surface (Mukai et al, 2010; Hao et al, 2012). Frameshift loss-of-function mutations in RNF43 that enhance WNT signaling have been identified in pancreatic and colorectal cancers; the proliferation of these cells is dependent on the presence of secreted WNT, as their growth is abrogated by treatment of cells with the Porcupine inhibitor LGK974 (Koo et al, 2012; Jiang et al, 2013)."
BMGC_PW1284,BMG_PW3778,,,"Activation of tumor necrosis factor receptor 1 (TNFR1) can trigger multiple signal transduction pathways to induce cell survival or cell death (Ward C et al. 1999; Micheau O and Tschopp J 2003; Widera D et al. 2006). While pro-survival signaling is initiated and regulated via the activated TNFR1 receptor complex at the cell membrane, cell death signals are induced upon the release of TRADD:TRAF2:RIP1 complex from the membrane to the cytosol where it forms death-inducing signaling complex (DISC) (Micheau O and Tschopp J 2003; Schneider-Brachert W et al. 2004). Upon apoptotic stimulation procaspase-8 or 10 is recruited into the DISC, and close proximity promotes the dimerization, autocatalytic processing, and activation of the initiator caspase-8 (and/or caspase-10) (Wang J et al. 2001; Boatright KM and Salvesen GS 2003). The initiator caspases then process and activate the downstream effector caspases such as caspase-3 in a proteolytic cascade (Stennicke HR et al. 1998). The effector caspases in turn cleave many diverse substrates, ultimately inducing cell death."
BMGC_PW1285,BMG_PW3779,,,"Tumor necrosis factor-alpha (TNFα) is an inflammatory cytokine, that activates either cell survival (e.g.,inflammation, proliferation) or cell death upon association with TNF receptor 1 (TNFR1). Stimuli and the cellular context dictate cell fate decisions between survival and death which rely on tightly regulated mechanisms with checkpoints on many levels. The TNFR1 signaling is controlled by the interplay between post-translational modifications such as proteolytic processing by active caspases or ubiquitination/deubiquitination by LUBAC or CYLD ubiquitin-editing complexes. TNFR1-mediated NFkappaB activation leads to the pro-survival transcriptional program that is both anti-apoptotic and highly proinflammatory. The constitutive NFkappaB or AP1 activation may lead to excessive inflammation which has been associated with a variety of aggressive tumor types (Jackson-Bernitsas DG et al. 2007; Zhang JY et al. 2007). Thus, the tight regulation of TNFα:TNFR1 signaling is required to ensure the appropriate cell response to stimuli."
BMGC_PW1286,BMG_PW3780,,,"Activation of tumor necrosis factor receptor 1 (TNFR1) can trigger multiple signal transduction pathways to induce inflammation, cell proliferation, survival or cell death (Ward C et al. 1999; Micheau O and Tschopp J 2003; Widera D et al. 2006). Whether a TNF-α-stimulated cell will survive or die is dependent on the cellular context. TNF-α-induced signals lead to the activation of transcriptional factors such as nuclear factor-kappa B (NFkappaB) and activator protein-1 (AP1) (Ward C et al. 1999; Widera D et al. 2006; Tsou HK et al. 2012). The binding of TNF-α to TNFR1 leads to recruitment of the adapter protein TNFR1-associated death domain (TRADD) and of receptor‑interacting protein 1 (RIPK1). TRADD subsequently recruits also TNF receptor-associated factor 2 (TRAF2). RIPK1 is promptly K63-polyubiquitinated which results in the recruitment of the TAB2:TAK1 complex and the IkB kinase (IKK) complex to TNFR1. The activated IKK complex mediates phosphorylation of the inhibitor of NFkappaB (IkB), which targets IkB for ubiquitination and subsequent degradation. Released NFkappaB induces the expression of a variety of genes including inflammation-related genes and anti-apoptotic genes encoding proteins such as inhibitor of apoptosis proteins cIAP1/2, Bcl-2, Bcl-xL or cellular FLICE-like inhibitory protein (FLIP) (Blonska M et al. 2005; Ea CK et al. 2006; Wu CJ et al. 2006; Chen C et al. 2000; Manna SK et al. 2000; Kreuz S et al. 2001; Micheau O et al. 2001). NFkB-mediated inhibition of cell death also involves attenuating TNF-induced activation of c-Jun activating kinase (JNK). Whereas transient activation of JNK upon TNF treatment is associated with cellular survival, prolonged JNK activation contributes to cell death. However, as caspases activate JNK quite efficiently, JNKs are also regularly stimulated in course of apoptosis without being essential for cell death (Wicovsky A et al. 2007). AP1-mediated gene induction results from activation of JNK via TRAF2 (not shown here) (Tsou HK et al. 2012). While pro-survival signaling is initiated and regulated via the activated TNFR1 receptor complex at the cell membrane, cell death signals are induced by internalization-associated fashion upon the release of RIPK1 from the membrane complex (Micheau O and Tschopp J 2003; Schneider-Brachert W et al. 2004; Tchikov V et al. 2011). TNFR1-mediated transcriptional activity of NFkB is both antiapoptotic and highly proinflammatory and thus must be tightly regulated to prevent constitutive activation that leads to persistent inflammation and cancer (Ward C et al. 1999; Fujihara S et al. 2002; Pekalski J et al. 2013; Kankaanranta H et al. 2014; Shukla S and Gupta S 2004; Jackson-Bernitsas DG et al. 2007; Zhang JY et al. 2007). Multiple mechanisms normally ensure the proper control of NFkappaB activation including two negative feedback loops mediated by NFkappaB inducible inhibitors, IkB-alpha (NFKBIA) and ubiquitin-editing protein A20 (He KL & Ting AT 2002; Wertz IE et al. 2004; Vereecke L et al. 2009; Pekalski J et al. 2013)."
BMGC_PW1287,BMG_PW3781,,,"Mammalian genomes encode three Hedgehog ligands, Sonic Hedgehog (SHH), Indian Hedgehog (IHH) and Desert Hedgehog (DHH). These secreted morphogens can remain associated with lipid rafts on the surface of the secreting cell and affect developmental processes in adjacent cells. Alternatively, they can be released by proteolysis or packaging into vesicles or lipoprotein particles and dispersed to act on distant cells. SHH activity is required for organization of the limb bud, notochord and neural plate, IHH regulates bone and cartilage development and is partially redundant with SHH, and DHH contributes to germ cell development in the testis and formation of the peripheral nerve sheath (reviewed in Pan et al, 2013). Despite divergent biological roles, all Hh ligands are subject to proteolytic processing and lipid modification during transit to the surface of the secreting cell (reviewed in Gallet, 2011). Precursor Hh undergoes autoproteolytic cleavage mediated by the C-terminal region to yield an amino-terminal peptide Hh-Np (also referred to as Hh-N) (Chen et al, 2011). No other well defined role for the C-terminal region of Hh has been identified, and the secreted Hh-Np is responsible for all Hh signaling activity. Hh-Np is modified with cholesterol and palmitic acid during transit through the secretory system, and both modifications contribute to the activity of the ligand (Porter et al, 1996; Pepinsky et al, 1998; Chamoun et al, 2001). At the cell surface, Hh-Np remains associated with the secreting cell membrane by virtue of its lipid modifications, which promote clustering of Hh-Np into lipid rafts (Callejo et al, 2006; Peters et al, 2004). Long range dispersal of Hh-Np depends on the untethering of the ligand from the membrane through a variety of mechanisms. These include release of monomers through the combined activity of the transmembrane protein Dispatched (DISP2) and the secreted protein SCUBE2, assembly into soluble multimers or apolipoprotein particles or release on the surface of exovesicles (Vyas et al, 2008; Tukachinsky et al, 2012; Chen 2004; Zeng et al, 2001; reviewed in Briscoe and Therond, 2013)."
BMGC_PW1288,BMG_PW3782,,,"Eukaryotic elongation factor 2 (EEF2) catalyzes the GTP dependent ribosomal translocation step during translation elongation. This function requires the presence of a posttranslational modification, the conversion of histidine residue 715 to diphthamide (2' [3 carboxamido 3 (trimethylammonio)propyl] L histidine) (Van Ness et al. 1978). No other protein is known to undergo this modification. The diphthamide residue is also the target of ADP ribosylation catalyzed by diphtheria toxin, which inactivates EEF2 and leads to cell death (Collier 1975; Pappenheim 1977). Diphthamide synthesis proceeds in four steps: the transfer of 3 amino 3 carboxypropyl group from S adenosylmethionine to histidine 715 of EEF2, the addition of four methyl groups to the 3 amino 3 carboxypropyl moiety, the demethylation of the methylated carboxylate group to form diphthine, and the amidation of the diphthine carboxyl group (Liu et al. 2004; Lin et al. 2014; Schaffrath et al. 2014; Su et al. 2013; Uthman et al. 2013)."
BMGC_PW1289,BMG_PW3783,,,"MSH2:MSH6 (MutSalpha) binds single base mismatches and unpaired loops of 1-2 nucleotides (reviewed in Edelbrock et al. 2013). Human cells contain about 6-fold more MSH2:MSH6 than MSH2:MSH3 (MutSbeta), which mediates repair of larger mismatches, and an imbalance in the ratio can cause a mutator phenotype (Drummond et al. 1997, Marra et al. 1998). The MSH6 subunit is responsible for binding the mismatch, which activates MSH2:MSH6 to exchange ADP for ATP, adopt the conformation to allow movement on the DNA, and interact with downstream effectors PCNA, MLH1:PMS2 and EXO1. The interaction with PCNA initiates excision of the recently replicated strand. MLH1:PMS2 has endonucleolytic activity and makes a nick that is enlarged to a gap of hundreds of nucleotides by EXO1. DNA is polymerized across the gap by DNA polymerase delta and the remaining nick is sealed by DNA ligase I."
BMGC_PW1290,BMG_PW3784,,,"MSH2:MSH3 (MutSbeta) binds unpaired loops of 2 or more nucleotides (Palombo et al. 1996, Genschel et al. 1998). Human cells contain about 6-fold more MSH2:MSH6 than MSH2:MSH3 (MutSbeta) and an imbalance in the ratio can cause a mutator phenotype (Drummond et al. 1997, Marra et al. 1998). Binding of the mismatch activates MSH2:MSH3 to exchange ADP for ATP, adopt the conformation to allow movement along the DNA, and interact with downstream effectors PCNA, MLH1:PMS2 and EXO1. The interaction with PCNA initiates excision of the recently replicated strand. MLH1:PMS2 makes a nick that is enlarged to a gap of hundreds of nucleotides by EXO1. DNA is polymerized across the gap by DNA polymerase delta and the remaining nick is sealed by DNA ligase I."
BMGC_PW1291,BMG_PW3785,,,"S33 mutations of beta-catenin interfere with GSK3 phosphorylation and result in stabilization and nuclear localization of the protein and enhanced WNT signaling (Groen et al, 2008; Nhieu et al, 1999; Clements et al, 2002; reviewed in Polakis, 2000). S33 mutations have been identified in cancers of the central nervous system, liver, endometrium and stomach, among others (reviewed in Polakis, 2000)."
BMGC_PW1292,BMG_PW3786,,,"S37 mutations of beta-catenin interfere with GSK3 phosphorylation and stabilize the protein, resulting in enhanced WNT pathway signaling (Nhieu et al, 1999; Clements et al, 2002; reviewed in Polakis, 2000). S37 mutations have been identified in cancers of the brain, liver, ovary and large intestine, among others (reviewed in Polakis, 2000)."
BMGC_PW1293,BMG_PW3787,,,"S45 mutants of beta-catenin have been identified in colorectal and hepatocellular carcinomas, soft tissue cancer and Wilms Tumors, among others (reviewed in Polakis, 2000). These mutations abolish the CK1alpha phosphorylation site of beta-catenin which acts as a critical priming site for GSK3 phosphorylation of T41( and subsequently S37 and S33) thus preventing its ubiquitin-mediated degradation (Morin et al, 1997; Amit et al, 2002)."
BMGC_PW1294,BMG_PW3788,,,"T41 mutations of beta-catenin interfere with GSK3 phosphorylation and result in stabilization and nuclear accumulation of the protein (Moreno-Bueno et al, 2002; Taniguchi et al, 2002; reviewed in Polakis, 2012). T41 mutations have been identified in cancers of the liver and brain, as well as in the pituitary, endometrium, large intestine and skin, among others (reviewed in Polakis, 2000; Saito-Diaz et al, 2013)."
BMGC_PW1295,BMG_PW3789,,,"Hh signaling is required for a number of developmental processes, and mutations that disrupt the normal processing and biogenesis of Hh ligand can result in neonatal abnormalities. SHH is one of a number of genes that have been associated with the congenital disorder holoprosencephaly, which causes abnormalities in brain and craniofacial development (Roessler et al, 2009; reviewed in Roessler and Muenke, 2011). SHH variants associated with the condition affect the autocatalytic processing of the precursor and dramatically impair the production of the secreted active Hh-Np, abrogating signaling (reviewed in Pan et al, 2013)."
BMGC_PW1296,BMG_PW3790,,,"Cholesterol and palmitoyl-modification of Hh-Np render the ligand highly hydrophobic and results in its close association with the plasma membrane of the producing cell after secretion. Hh-Np tethered in this way may cluster in sterol-rich lipid rafts where it is competent for short-range signaling. Cell surface Hh-Np also interacts with glypican components of the extracellular matrix and this interaction stabilizes the ligand and is required for its lateral spread. Together, clustering into lipid rafts and interaction with HSPGs may favour packaging of ligand into higher order forms required for ligand dispersal. Long-range signaling requires release of Hh-Np from the secreting cell. Release is achieved through a number of possibly overlapping mechanisms. These include oligomerization into micelle-like structures, packaging into lipoprotein particles and interaction with cholesterol-binding adaptor proteins such as DISP and SCUBE2. In addition, Hh-Np can be released from the plasma membrane through proteolytic cleavage: NOTUM is a secreted enzyme that is thought to promote the release of Hh-Np by cleaving the GPI anchor of Hh-associated glypicans, while the transmembrane metalloprotease ADAM17 promotes long-range Hh signaling by removing the palmitoyl- and cholesterol-modified N- and C-termini of the membrane-associated ligand. How all these mechanisms are coordinated remains to be elucidated (reviewed in Briscoe and Therond, 2013; Gallet, 2011)."
BMGC_PW1297,BMG_PW3791,,,"Translation initiates with the mitochondrial mRNA binding the 28S subunit:MTIF3 (28S subunit:IF-3Mt, 28S subunit:IF3mt) complex together with MTIF2:GTP (IF-2Mt:GTP, IF2mt:GTP) (reviewed in Christian and Spremulli 2012, Kuzmenko et al. 2014). As inferred from bovine homologs, the 28S subunit, 39S subunit, and 55S holoribosome associate with the matrix-side face of the inner membrane and the translation products are inserted into the inner membrane as translation occurs (Liu and Spremulli 2000). Mitochondrial mRNAs have either no untranslated leader or short leaders of 1-3 nucleotides, with the exception of the 2 bicistronic transcripts, RNA7 and RNA14, which have overlapping orfs that encode ND4L/ND4 and ATP8/ATP6 respectively.. Binding of N-formylmethionine-tRNA to the start codon results in a stable complex between the mRNA and the 28S subunit while absence of a start codon at the 5' end of the mRNA causes the mRNA to slide though the 28S subunit and eventually dissociate. The 39S subunit then binds the 28S subunit:mRNA complex, GTP is hydrolyzed, and the initiation factors MTIF3 and MTIF2:GDP dissociate."
BMGC_PW1298,BMG_PW3793,,,"Hh signaling is required for a number of developmental processes, and mutations that disrupt the normal processing and biogenesis of Hh ligand can result in neonatal abnormalities. SHH is one of a number of genes that have been associated with the congenital disorder holoprosencephaly, which causes abnormalities in brain and craniofacial development (Roessler et al, 2009; reviewed in Roessler and Muenke, 2011). SHH variants associated with the condition affect the autocatalytic processing of the precursor and dramatically impair the production of the secreted active Hh-Np, abrogating signaling (reviewed in Pan et al, 2013). Aberrant Hh signaling is also associated with gondal dysgenesis syndromes in which palmitoylation of DHH is abrogated by mutation of the acyltransferase HHAT (Callier et al, 2014)."
BMGC_PW1299,BMG_PW3794,,,"Translation elongation proceeds by cycles of aminoacyl-tRNAs binding, peptide bond formation, and displacement of deacylated tRNAs (reviewed in Christian and Spremulli 2012). In each cycle an aminoacyl-tRNA in a complex with TUFM:GTP (EF-Tu:GTP) binds a cognate codon at the A-site of the ribosome, GTP is hydrolyzed, and TUFM:GDP dissociates. The elongating polypeptide bonded to the tRNA at the P-site is transferred to the aminoacyl group at the A-site by peptide bond formation, leaving a deacylated tRNA at the P-site and the elongating polypeptide attached to the tRNA at the A-site. GFM1:GTP (EF-Gmt:GTP) binds, GTP is hydrolyzed, GFM1:GDP dissociates, and the ribosome translocates 3 nucleotides in the 3' direction, relocating the peptidyl-tRNA to the P-site and allowing another cycle to begin. Mitochondrial ribosomes associate with the inner membrane and polypeptides are co-translationally inserted into the membrane (reviewed in Ott and Herrmann 2010, Agrawal and Sharma 2012). TUFM:GDP is regenerated to TUFM:GTP by the guanine nucleotide exchange factor TSFM (EF-Ts, EF-TsMt)."
BMGC_PW1300,BMG_PW3795,,,"Translation is terminated when MTRF1L:GTP (MTRF1a:GTP) recognizes a UAA or UAG termination codon in the mRNA at the A site of the ribosome (Soleimanpour-Lichaei et al. 2007, reviewed in Richter et al. 2010, Chrzanowska-Lightowlers et al. 2011. Christian and Spremulli 2012). GTP is hydrolyzed, and the aminoacyl bond between the translated polypeptide and the final tRNA at the P site is hydrolyzed by the 39S ribosomal subunit, releasing the translated polypeptide. MRRF (RRF) and GFM2:GTP (EF-G2mt:GTP) then act to release the remaining tRNA and mRNA from the ribosome and dissociate the 55S ribosome into 28S and 39S subunits."
BMGC_PW1301,BMG_PW3797,,,"Aflatoxins are among the principal mycotoxins produced as secondary metabolites by the molds Aspergillus flavus and Aspergillus parasiticus that contaminate economically important food and feed crops (Wild & Turner 2002). Aflatoxin B1 (AFB1) is the most potent naturally occurring carcinogen known and is also an immunosuppressant. It is a potent hepatocarcinogenic agent in many species, and has been implicated in the etiology of human hepatocellular carcinoma. Poultry, especially turkeys, are extremely sensitive to the toxic and carcinogenic action of AFB1 present in animal feed, resulting in multi-million dollar losses to the industry. Discerning the biochemical and molecular mechanisms of this extreme sensitivity of poultry to AFB1 will help with the development of new strategies to increase aflatoxin resistance (Rawal et al. 2010, Diaz & Murcia 2011). AFB1 has one major genotoxic metabolic fate, conversion to AFXBO, and several others that are less mutagenic but that can still be quite toxic. AFB1 can be oxidised to the toxic AFB1 exo 8,9 epoxide (AFXBO) product by several cytochrome P450 enzymes, especially P450 3A4 in the liver. This 8,9 epoxide can react with the N7 atom of a guanyl base of DNA to produce adducts by intercalating between DNA base pairs. The exo epoxide is unstable in solution, however, and can react spontaneously to form a diol that is no longer reactive with DNA. The diol product in turn undergoes base-catalysed rearrangement to a dialdehyde that can react with protein lysine residues. AFB1 can also be metabolised to products (AFQ1, AFM1, AFM1E) which have far less genotoxic consequences than AFB1. The main route of detoxification of AFB1 is conjugation of its reactive 8,9-epoxide form with glutathione (GSH). This reaction is carried out by trimeric glutathione transferases (GSTs), providing a chemoprotective mechanism against toxicity. Glutathione conjugates are usually excreted as mercapturic acids in urine (Guengerich et al. 1998, Hamid et al. 2013). The main metabolic routes of aflatoxin in humans are described here."
BMGC_PW1302,BMG_PW3799,,,"Mutations in the APC tumor suppressor gene are common in colorectal and other cancers and cluster in the central mutation cluster region (MCR) of the gene (Miyoshi et al, 1992; Nagase and Nakamura, 1993; Dihlmann et al, 1999; reviewed in Bienz and Clevers, 2000). These mutations generally result in truncated proteins that destabilize the destruction complex and result in elevated WNT pathway activation (reviewed in Polakis, 2000)."
BMGC_PW1303,BMG_PW3800,,,"Alterations in AXIN1 have been detected in a number of different cancers including liver and colorectal cancer and medullablastoma, among others (reviewed in Salahshor and Woodgett, 2005). Missense and nonsense mutations that disrupt or remove protein-protein interaction domains are common, and AXIN variants in cancers tend to disrupt the formation of a functional destruction complex (Satoh et al, 2000; Taniguchi et al, 2002; Webster et al, 2000; Shimizu et al, 2002)."
BMGC_PW1304,BMG_PW3803,,,"AMER1/WTX is a known component of the destruction complex and interacts directly with beta-catenin through the C-terminal half (Major et al, 2007). siRNA depletion of AMER1 in mammalian cells stabilizes cellular beta-catenin levels and increases the expression of a beta-catenin-dependent reporter gene, suggesting that AMER1 is a tumor suppressor gene (Major et al, 2007; reviewed in Huff, 2011). Consistent with this, nonsense and missense mutations that truncate AMER1 and result in loss of the beta-catenin binding region have been identified in Wilms tumor, a pediatric kidney cancer (Ruteshouser et al, 2008; Wegert et al, 2009)."
BMGC_PW1305,BMG_PW3804,,,"The organic cation transporters comprise three SLC22 members, OCT1-3. They can transport a wide range of organic cations including weak bases. All transport by OCTs is electrogenic, sodium-independent and bidirectional. Two further organic cation transporters mediate transport of ergothioneine and carnitine (Koepsell H and Endou H, 2004)."
BMGC_PW1306,BMG_PW3805,,,"The SLC22 gene family of solute carriers function as organic cation transporters (OCTs), cation/zwitterion transporters (OCTNs) and organic anion transporters (OATs). The SLC22 family belongs to the major facilitator superfamily and comprises uniporters, symporters and antiporters.Most of this family are polyspecific transporters. Since many of these transporters are expressed in the liver, kidney and intestine, they play an important role in drug absorption and excretion. Substrates include xenobiotics, drugs, and endogenous amine compounds (Koepsell H and Endou H, 2004)."
BMGC_PW1307,BMG_PW3808,,,"Phase 4 describes the membrane potential when a cell is not being stimulated. The normal resting potential in the ventricular myocardium is between -85 to -95 mV. The membrane is most permeable to K+ and relatively impermeable to other ions therefore the K+ gradient across the cell membrane is the key determinant in the normal resting potential (Park & Fishman 2011, Grant 2009). In this phase, K+ currents are generated by inward rectifier potassium channels (KCNJs) and tandem pore domain K+ channels (KCNKs). Some Na+/K+-ATPases and Na+/Ca2+-exchangers can also play roles during this phase."
BMGC_PW1308,BMG_PW3809,,,"In phase 3 (the ""rapid repolarisation"" phase), the L-type Ca2+ channels close, while the slow delayed rectifier (IKs) K+ channels remain open as more K+ leak channels open. This ensures a net outward positive current, corresponding to negative change in membrane potential, thus allowing more types of K+ channels to open. These are primarily the rapid delayed rectifier K+ channels (IKr) and the inwardly rectifying K+ current, IK1 (Kir). This net outward, positive current (equal to loss of positive charge from the cell) causes the cell to repolarize. The primary delayed rectifier K+ currents (IKs and IKr) are generated by K+ efflux mediated by potassium voltage-gated channel subfamily KQT member 1 (KCNQ1 aka Kv7.1) and potassium voltage-gated channel subfamily H member 2 (KCNH2 aka HERG) channels respectively (Park & Fishman 2011, Grant 2009). Specific to the atria, an ultra-rapidly activating delayed rectifier outward K+ current (IKur) generated primarily by potassium voltage-gated channel subfamily A member 5 (KCNA5) helps to repolarize atrial cells (Wang et al. 1993, Feng et al. 1997)."
BMGC_PW1309,BMG_PW3810,,,"The normal sequence of contraction of atria and ventricles of the heart require activation of groups of cardiac cells. The mechanism must elicit rapid changes in heart rate and respond to changes in autonomic tone. The cardiac action potential controls these functions. Action potentials are generated by the movement of ions through transmembrane ion channels in cardiac cells. Like skeletal myocytes (and axons), in the resting state, a given cardiac myocyte has a negative membrane potential. In both muscle types, after a delay (the absolute refractory period), K+ channels reopen and the resulting flow of K+ out of the cell causes repolarisation. The voltage-gated Ca2+ channels on the cardiac sarcolemma membrane are generally triggered by an influx of Na+ during phase 0 of the action potential. Cardiac muscle cells are so tightly bound that when one of these cells is excited the action potential spreads to all of them. The standard model used to understand the cardiac action potential is the action potential of the ventricular myocyte (Park & Fishman 2011, Grant 2009). The action potential has 5 phases (numbered 0-4). Phase 4 describes the membrane potential when a cell is not being stimulated. The normal resting potential in the ventricular myocardium is between -85 to -95 mV. The K+ gradient across the cell membrane is the key determinant in the normal resting potential. Phase 0 is the rapid depolarisation phase in which electrical stimulation of a cell opens the closed, fast Na+ channels, causing a large influx of Na+ creating a Na+ current (INa+). This causes depolarisation of the cell. The slope of phase 0 represents the maximum rate of potential change and differs in contractile and pacemaker cells. Phase 1 is the inactivation of the fast Na+ channels. The transient net outward current causing the small downward deflection (the ""notch"" of the action potetial) is due to the movement of K+ and Cl- ions. In pacemaker cells, this phase is due to rapid K+ efflux and closure of L-type Ca2+ channels. Phase 2 is the plateau phase which is sustained by a balance of Ca2+ influx and K+ efflux. This phase sustains muscle contraction. Phase 3 of the action potential is where a concerted action of two outward delayed currents brings about repolarisation back down to the resting potential (Bartos et al. 2015)."
BMGC_PW1310,BMG_PW3811,,,"Phase 0 is the rapid depolarisation phase in which electrical stimulation of a cell initiates events involving the influx and efflux of ions resulting in the production of a cell's action potential. The cell's excitation opens the closed, fast Na+ channel proteins, causing a large influx of Na+ creating a Na+ current (INa+). This causes depolarisation of the cell then voltage-dependent L-type calcium channels (LTCCs) transport Ca2+ into excitable cells. The slope of phase 0 represents the maximum rate of potential change and differs in contractile and pacemaker cells. The potential in this phase changes from around -90mV to around +50mV (Park & Fishman 2011, Grant 2009)."
BMGC_PW1311,BMG_PW3812,,,"Phase 2 of the cardiac action potential is the plateau phase which is sustained by a balance of Ca2+ influx through L-type Ca2+ channels (LTCCs) and K+ efflux through the slow delayed rectifier K+ channel 1 (KCNQ1). This phase sustains muscle contraction (Park & Fishman 2011, Grant 2009)."
BMGC_PW1312,BMG_PW3814,,,"Recent evidence indicates that small RNAs participate in transcriptional regulation in addition to post-transcriptional silencing. Components of the RNAi machinery (ARGONAUTE1 (AGO1, EIF2C1), AGO2 (EIF2C2), AGO3 (EIF2C3), AGO4 (EIF2C4), TNRC6A, and DICER) are observed associated with microRNAs (miRNAs) in both the cytosol and the nucleus (Robb et al. 2005, Weinmann et al. 2009, Doyle et al. 2013, Nishi et al. 2013, Gagnon et al. 2014). The AGO:miRNA complexes are imported into the nucleus by IMPORTIN-8 (IPO8, IMP8, RANBP8) and also by an unknown importin while associated with the nuclear shuttling protein TNRC6A (reviewed in Schraivogel and Meister 2014). Within the nucleus, AGO2, TNRC6A, and DICER may associate in a complex (Gagnon et al. 2014). Nuclear AGO1 and AGO2 in complexes with small RNAs are observed to activate transcription (RNA activation, RNAa) or repress transcription (Transcriptional Gene Silencing, TGS) of genes that contain sequences matching the small RNAs (reviewed in Malecova and Morris 2010, Huang and Li 2012, Gagnon and Corey 2012, Huang and Li 2014, Salmanidis et al. 2014, Stroynowska-Czerwinska et al. 2014). TGS is associated with methylation of cytosine in DNA and methylation of histone H3 at lysine-9 and lysine-27 (Castanotto et al. 2005, Suzuki et al. 2005, Kim et al. 2006, Weinberg et al. 2006, Kim et al. 2008, reviewed in Malecova and Morris 2010, Li et al. 2014); RNAa is associated with methylation of histone H3 at lysine-4 (Huang et al. 2012, reviewed in Li et al. 2014). Small RNAs in the nucleus have also been shown to play roles in alternative splicing (Liu et al., 2012, Ameyar-Zazoua et al., 2012) and DNA damage repair (Wei et al., 2012; Francia et al., 2012). Nevertheless, elucidation of the detailed mechanisms of small RNA action requires further research."
BMGC_PW1313,BMG_PW3815,,,Cardiovascular homeostasis can be regulated by natriuretic peptides (Pandey 2014).
BMGC_PW1314,BMG_PW3816,,,"Ion channels and ion homeostasis in relation to cardiac conduction is described in this section (Couette et al. 2006, Bartos et al. 2015)."
BMGC_PW1315,BMG_PW3842,,,"Cholesterol side-chain cleavage enzyme, mitochondrial (CYP11A1) normally catalyses the side-chain cleavage of cholesterol to form pregnenolone. Defects in CYP11A1 can cause Adrenal insufficiency, congenital, with 46,XY sex reversal (AICSR; MIM:613743). This is a rare disorder that can present as acute adrenal insufficiency in infancy with elevated ACTH and plasma renin activity and low or absent adrenal steroids. The severest phenotype is loss-of-function mutations associated with prematurity, complete under-androgenisation and severe, early-onset adrenal failure (Kim et al. 2008)."
BMGC_PW1316,BMG_PW3845,,,"The ability to process xenobiotica and many endogenous compounds is called biotransformation and is catalysed by enzymes mainly in the liver of higher organisms but also a number of other organs such as kidneys, gut and lungs. Metabolism occurs in two stages; phase 1 functionalisation and phase 2 conjugation. Defects in enzymes in these two phases can lead to disease (Nebert et al. 2013, Pikuleva & Waterman 2013, Zanger & Schwab 2013, Mudd 2013, Messenger et al. 2013, Aoyama & Nakaki 2013, Shih 2004, Millington 2013, Azimi et al. 2014, Sticova & Jirsa 2013)."
BMGC_PW1317,BMG_PW3847,,,"The precursor peptide pro-opiomelanocortin (POMC) gives rise to many peptide hormones through cleavage. The cleavage products corticotropin (ACTH) and beta-lipotropin give rise to smaller peptides that have distinct biologic activities: alpha-melanotropin and corticotropin-like intermediate lobe peptide (CLIP) are formed from ACTH; gamma-LPH and beta-endorphin are formed from beta-LPH. ACTH (POMC(138-176) stimulates the adrenal glands to release cortisol, a glucocorticoid released in response to stress whose primary functions are to stimulate gluconeogenesis, suppress the immune system and aid metabolism of fats, proteins and carbohydrates. Defects in ACTH can cause obesity (MIM:601665) resulting in excessive accumulation of body fat (Challis et al. 2002, Millington 2013). Defects in ACTH can also cause pro-opiomelanocortinin deficiency (POMCD; MIM:609734) where affected individuals present early-onset obesity, adrenal insufficiency and red hair (Krude et al. 1998, Krude et al. 2003)."
BMGC_PW1318,BMG_PW3849,,,"In germ cells of humans and mice, precursors of PIWI-interacting RNAs (piRNAs) are transcribed from a few hundred sequence clusters, as well as individual transposons, intergenic regions, and genes in the genome. These longer transcripts are processed to yield piRNAs of 26-30 nucleotides independently of DICER, the enzyme responsible for microRNAs (miRNAs) and small interfering RNAs (siRNAs) (reviewed in Girard and Hannon 2008, Siomi et al. 2011, Ishizu et al. 2012, Pillai and Chuma 2012, Bortvin 2013, Chuma and Nakano 2013, Sato and Siomi 2013). The initial step in processing long transcripts to piRNAs is cleavage by PLD6 (MitoPLD), which generates the mature 5' end. The cleavage products of PLD6 are bound by either PIWIL1 (HIWI, MIWI) or PIWIL2 (HILI, MILI) in complexes with several other proteins. The 3' end is trimmed by an unknown exonuclease to generate the mature piRNA. PIWIL1:piRNA complexes appear to be involved in post-transcriptional silencing in the cytosol while PIWIL2:piRNA complexes generate further piRNAs from transposon transcripts and other transcripts in the cytosol. Cleavage products from PIWIL2:piRNA may be loaded into either PIWIL2 or PIWIL4 (HIWI2, MIWI2). Loading into PIWIL2 forms a step in a cytosolic amplification loop called the ""ping-pong cycle"" which yields further PIWIL2:piRNA complexes from cleaved precursor RNAs. Loading into PIWIL4 yields a complex also containing TDRD9 that translocates to the nucleus and directs DNA methylation of cognate loci, causing transcriptional silencing during spermatogenesis. Transcriptional silencing by piRNAs is necessary to limit transposition of endogenous transposons such as L1 elements in the genome."
BMGC_PW1319,BMG_PW3850,,,"Toll like receptors (TLRs) are sensors of the innate immune system that detect danger signals derived from pathogens (pathogen-associated molecular patterns - PAMP) or damaged cells (damage-associated molecular patterns - DAMP) (Pasare C and Medzhitov R 2005; Barton GM and Kagan JC 2009; Kawai T and Akira S 2010). Signaling by these sensors promotes the activation and nuclear translocation of transcription factors (IRFs, NFkB and AP1). The transcription factors induce secretion of inflammatory cytokines such as IL-6, TNF and pro-IL1beta that direct the adaptive immune response. Inherited or acquired abnormalities in TLR-mediated processes may lead to increased susceptibility to infection, excessive inflammation, autoimmunity and malignancy (Picard C et al. 2010; Netea MG et al. 2012; Varettoni M et al. 2013). Here we describe four primary immunodeficiency (PID) disorders associated with defective TLR-mediated responses. First, MyD88 or IRAK4 deficiency is characterized with a greater susceptibility to pyogenic bacteria in affected patients (Picard C et al. 2003; von Bernuth H et al. 2008). Second, defects in the TLR3 signaling pathway are associated with a greater susceptibility to herpes simplex virus encephalitis (Zhang SY et al. 2013). Third, imunodeficiencies due to defects in NFkB signaling components are linked to impaired TLR-mediated responses (Courtois G et al. 2003; Fusco F et al. 2004). Finally, events are annotated showing constitutive activation of a somatically mutated MyD88 gene which results in malignancy (Varettoni M et al. 2013)."
BMGC_PW1320,BMG_PW3853,,,"Myeloid differentiation primary response (MyD88) is an adaptor protein that mediates intracellular signaling pathways evoked by all Toll-like receptors (TLRs) except for TLR3 and by several interleukin-1 receptors (IL-1Rs) (Medzhitov R et al. 1998). Upon ligand binding, TLRs hetero- or homodimerize and recruit MyD88 through their respective TIR domains. Then, MyD88 oligomerizes via its death domain (DD) and TIR domain and interacts with the interleukin-1 receptor-associated kinases (IRAKs) to form the Myddosome complex (MyD88:IRAK4:IRAK1/2) (Motshwene PG et al. 2009; Lin SC et al. 2010). The Myddosome complex transmits the signal leading to activation of transcription factors such as nuclear factor-kappaB (NFkB) and activator protein 1 (AP1). Studies have identified patients with autosomal recessive (AR) form of MyD88 deficiency caused by homozygous or compound heterozygous mutations in MYD88 gene leading to abolished protein production (von Bernuth et al. 2008). AR MyD88 deficiency is a type of a primary immunodeficiency characterized by greater susceptibility to pyogenic bacteria (such as Streptococcus pneumoniae, Staphylococcus aureus or Pseudomonas aeruginosa) manifested in infancy and early childhood. Patients with MyD88 deficiency show delayed or weak signs of inflammation (Picard C et al. 2010; Picard C et al. 2011). Functional assessment of MyD88 deficiency revealed that cytokine responses were impaired in patient-derived blood cells upon stimulation with the agonists of TLR2 and TLR4 (PAM2CSK4 and LPS respectively), although some were produced in response to LPS. (von Bernuth et al. 2008). NFkB luciferase reporter gene assays using human embryonic kidney 293 (HEK293T) cells showed that MyD88 variants, S34Y, E52del, E53X, L93P, R98C, and R196C, were compromised in their ability to enhance NFkB activation (Yamamoto T et al. 2014). The molecular basis for the observed functional effects (reported for selected mutations) probably faulty Myddosome formation due to impaired MyD88 oligomerization and/or interaction with IRAK4 (George J et al. 2011; Nagpal K et al. 2011; Yamamoto T et al. 2014). While MyD88-deficiency might be expected to perturb MyD88?IRAK4 dependent TLR7 and TLR8 signaling events associated with the sensing viral infections, patients with MyD88 and IRAK4 deficiencies have so far not been reported to be susceptible to viral infection."
BMGC_PW1321,BMG_PW3858,,,"Many signaling pathways rely on the activation of nuclear factor kappa B (NFkB), which is critical for the induction of the appropriate cellular function in response to various stimuli such as inflammatory cytokines, microbial products or various types of stress (Lawrence T 2009; Hoesel B and Schmid JA 2013). The NFkB family of transcription factors is kept inactive in the cytoplasm by inhibitor of kappa B (IkB) family members (Oeckinghaus A and Ghosh S 2009). Canonical NFkB activation depends on the phosphorylation of IkB by the I kappa B kinase (IKK) complex, which contains two catalytic subunits named IKK alpha, IKK beta and a regulatory subunit named NFkB essential modulator (NEMO or IKBKG) (Rothwarf DM et al. 1998). Phosphorylation of IkB leads to K48-linked ubiquitination and proteasomal degradation of IkB, allowing translocation of NFkB factor to the nucleus, where it can activate transcription of a variety of genes participating in the immune and inflammatory response, cell adhesion, growth control, and protection against apoptosis (Collins T et al. 1995; Kaltschmidt B et al. 2000; Lawrence T 2009). IKBKG is encoded by an X-linked gene. Null alleles of the gene are lethal in hemizygous males, whereas hypomorphic alleles typically result in the impaired NFkB signaling in patients with a broad spectrum of clinical phenotypes in terms of both developmental defects and immunodeficiency (Döffinger R et al. 2001; Hanson EP et al. 2008). Several categories of mutations affecting IKBKG have been reported in humans (Döffinger R et al. 2001; Vinolo E et al. 2006; Fusko F et al. 2008). The first category of these mutations consists of hypomorphic mutations typically involving the zinc finger domain and nearby C-terminal regions and causing hypohidrotic ectodermal dysplasia with immune deficiency (HED-ID) in males (Jain A et al. 2001; Shifera AS 2010). The second category consists of amorphic mutations causing incontinentia pigmenti (IP) in females and, generally, prenatal death in males (Aradhya S et al. 2001; Fusco F et al. 2004). The third category is composed of hypomorphic mutations involving the stop codon causing anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID), osteopetrosis and lymphedema (OL-EDA-ID) in males (Döffinger R et al. 2001). Also some patients with a defective IKBKG gene can develop immunodeficiency without ectodermal dysplasia (Orange JS et al. 2004). This module describes several EDA-ID-associated hypomorphic IKBKG mutations that have been reported to affect inflammatory responses initiated by toll like receptors (TLR)."
BMGC_PW1322,BMG_PW3859,,,"The nuclear factor kappa B (NFkB) family of transcription factors is kept inactive in the cytoplasm by the inhibitor of kappa B (IkB) family members IKBA (IkB alpha, NFKBIA), IKBB (IkB beta, NFKBIB) and IKBE (IkB epsilon, NFKBIE) (Oeckinghaus A and Ghosh S 2009). Multiple stimuli such as inflammatory cytokines, microbial products or various types of stress activate NFkB signaling leading to stimuli-induced phosphorylation of IkB molecule (Scherer DC et al. 1995; Alkalay I et al. 1995; Lawrence T 2009; Hoesel B and Schmid JA 2013). The phosphorylation of IkB proteins triggers their polyubiquitination and subsequent degradation by 26S proteasome, allowing free NFkB dimer to translocate to the nucleus where it directs the expression of target genes. Studies have identified an autosomal dominant form of ectodermal dysplasia with immunodeficiency (AD-EDA-ID) caused by a hypermorphic heterozygous mutation of NFKBIA/IKBA gene. The IKBA defects prevent the phosphorylation and degradation of IKBA protein resulting in gain-of-function condition with the enhanced inhibitory capacity of IKBA in sequestering NF?B dimers in the cytoplasm (Courtois G et al. 2003; Lopes-Granados E et al. 2008; Schimke LF et al. 2013)."
BMGC_PW1323,BMG_PW3861,,,"Interleukin-1 receptor-associated kinase 4 (IRAK4) is a serine/threonine kinase, that mediates activation of transcriptional factors such as NFkB and AP1 downstream of IL-1 receptors and all toll like receptors (TLR) except for TLR3 (Suzuki N et al. 2002). IRAK4 is recruited to the TLR receptor complex through a homophilic interaction of the death domains of IRAK4 and adaptor myeloid differentiation factor 88 protein (MyD88) (Motshwene PG et al. 2009; Lin SC et al. 2010). Studies have identified patients with an autosomal recessive (AR) form of IRAK4 deficiency, a health condition with clinical manifestation in infancy or early childhood, that predisposes affected patients to recurrent pyogenic bacterial infection (e.g., Streptococcus pneumoniae and Staphylococcus aureus) (Picard C et al. 2003; Ku CL et al. 2007; Picard C et al. 2010; Picard C et al. 2011). Leukocytes derived from IRAK4-deficient patients display a lack of production of inflammatory cytokines such as TNF alpha, IL-6 and IL-1 beta by whole blood or a lack of CD62 ligand (CD62L) shedding from granulocytes following activation with the most TLR agonists including those of TLR1/2 (Pam3CSK4), TLR2/6 (Pam2CSK4) and TLR4 (LPS) (Picard C et al. 2003; McDonald DR et al. 2006; Ku CL et al. 2007). However, LPS-induced TLR4-mediated production of some cytokines (IL8 and MIP-1beta) was reduced but not abolished (Ku CL et al. 2007). LPS-stimulated induction of type I IFN via MyD88-IRAK4 independent signaling axis was normal or weakly affected suggesting that TLR4 could induce some responses in IRAK4 deficient patients(Yang K et al. 2005). Patients with AR IRAK4 deficiency were found to bear homozygous or compound heterozygous mutations in the IRAK4 gene (Picard C et al. 2003; Ku CL et al. 2007; McDonald DR et al. 2006). Here we describe selected mutations, that have been functionally characterized. Cell-based assay as well as in vitro protein-interaction analyses with IRAK4 variants showed that the loss-of-function of defective IRAK4 is caused by either loss of protein production (reported for IRAK4 Q293* and E402*) or an impaired interaction with MyD88 as shown for missense mutation IRAK4 R12C (Ku CL et al. 2007; Yamamoto T et al. 2014). Besides defective TLR2/4 mediated signaling, the Reactome module describes the impact of functional deficiency of IRAK4 on TLR5 pathways. The module does not include defective TLR7, TLR8 and TLR9 signaling events, which are associated mostly with viral infections, although studies using patient-derived blood cells showed abolished cytokine production by peripheral blood mononuclear cells (PBMCs) and lack of CD62 ligand (CD62L) shedding from granulocytes in response to TLR7-9 agonists (McDonald DR et al. 2006; von Bernuth H et al. 2006; Ku CL et al. 2007). In addition to the TLR-NFkappaB signaling axis, endosomic TLR7-9 activates IFN-alpha/beta and IFN-gamma responses and these are also impaired in IRAK4-deficient PBMC (Yang K et al. 2005). Nevertheless, IFN-alpha/beta and -gamma production in IRAK-4-deficient blood cells in response to 9 of 11 viruses was normal or weakly affected, suggesting that IRAK-4-deficient patients may control viral infections by TLR7-9-independent production of IFNs such as IRAK4-independent antiviral RIGI and MDA5 pathways (Yang K et al. 2005). So it is not yet possible to annotate a definitive molecular pathway between IRAK-4 deficiency and changes in TLR7-9 signaling."
BMGC_PW1324,BMG_PW3862,,,"In addition to the activation of canonical NF-kB subunits, activation of SYK pathway by Dectin-1 leads to the induction of the non-canonical NF-kB pathway, which mediates the nuclear translocation of RELB-p52 dimers through the successive activation of NF-kB-inducing kinase (NIK) and IkB kinase-alpha (IKKa) (Geijtenbeek & Gringhuis 2009, Gringhuis et al. 2009). Noncanonical activity tends to build more slowly and remain sustained several hours longer than does the activation of canonical NF-kB. The noncanonical NF-kB pathway is characterized by the post-translational processing of NFKB2 (Nuclear factor NF-kappa-B) p100 subunit to the mature p52 subunit. This subsequently leads to nuclear translocation of p52:RELB (Transcription factor RelB) complexes to induce cytokine expression of some genes (C-C motif chemokine 17 (CCL17) and CCL22) and transcriptional repression of others (IL12B) (Gringhuis et al. 2009, Geijtenbeek & Gringhuis 2009, Plato et al. 2013)."
BMGC_PW1325,BMG_PW3863,,,"CLEC7A (Dectin-1) signals through the classic calcineurin/NFAT pathway through Syk activation phospholipase C-gamma 2 (PLCG2) leading to increased soluble IP3 (inositol trisphosphate). IP3 is able to bind endoplasmic Ca2+ channels, resulting in an influx of Ca2+ into the cytoplasm. This increase in calcium concentration induces calcineurin activation and consequently, dephosphorylation of NFAT and its translocation into the nucleus, triggering gene transcription and extracellular release of Interleukin-2 (Plato et al. 2013, Goodridge et al. 2007, Mourao-Sa et al. 2011)."
BMGC_PW1326,BMG_PW3864,,,"CLEC7A (also known as Dectin-1) is a pattern-recognition receptor (PRR) expressed by myeloid cells (macrophages, dendritic cells and neutrophils) that detects pathogens by binding to beta-1,3-glucans in fungal cell walls and triggers direct innate immune responses to fungal and bacterial infections. CLEC7A belongs to thetype-II C-type lectin receptor (CLR) family that can mediate its own intracellular signaling. Upon binding particulate beta-1,3-glucans, CLEC7A mediates intracellular signalling through its cytoplasmic immunoreceptor tyrosine-based activation motif (ITAM)-like motif (Brown 2006). CLEC7A signaling can induce the production of various cytokines and chemokines, including tumour-necrosis factor (TNF), CXC-chemokine ligand 2 (CXCL2, also known as MIP2), interleukin-1beta (IL-1b), IL-2, IL-10 and IL-12 (Brown et al. 2003), it also triggers phagocytosis and stimulates the production of reactive oxygen species (ROS), thus contributing to microbial killing (Gantner et al. 2003, Herre et al. 2004, Underhill et al. 2005, Goodridge at al. 2011, Reid et al. 2009). These cellular responses mediated by CLEC7A rely on both Syk-dependent and Syk-independent signaling cascades. The pathways leading to the Syk-dependent activation of NF-kB can be categorised into both canonical and non-canonical routes (Gringhuis et al. 2009). Activation of the canonical NF-kB pathway is essential for innate immunity, whereas activation of the non-canonical pathway is involved in lymphoid organ development and adaptive immunity (Plato et al. 2013)."
BMGC_PW1327,BMG_PW3868,,,"Organic anion transporters (OATs) mediate the renal absorption and excretion of a broad range of endogenous substrates and anionic drugs such as diuretics and NSAIDs. Five members belong to these polyspecific transporters (OAT1-4 and URAT1) and are predominantly expressed in the kidney (Koepsell H and Endou H, 2004; Rizwan AN and Burckhardt G, 2007; Ahn SY and Bhatnagar V, 2008)."
BMGC_PW1328,BMG_PW3869,,,"GLI1 is the most divergent of the 3 mammalian GLI transcription factors and lacks a transcriptional repressor domain. Although GLI1 is dispensible for development, the gene is an early transcriptional target of Hh signaling and the protein contributes a minor activation function in mammals (Dai et al, 1999; Bai et al, 2002; Park et al, 2000). In the absence of Hh signaling, GLI1 is completely degraded by the proteasome, in contrast to the partial processing that occurs with GLI3. This differential response reflects the absence in GLI1 of two of the three elements identified in GLI3 that promote partial proteolysis; these are the zinc finger region, present in all GLI proteins, and an adjacent linker sequence and the degron, neither of which are found in the GLI1 protein (Schrader et al, 2011; Pan and Wang, 2007)."
BMGC_PW1329,BMG_PW3870,,,"The primary role of the GLI2 protein is as an activator of Hh-dependent signaling upon pathway stimulation; in the absence of Hh ligand, a small fraction of GLI2 appears to be processed to a repressor form, but the bulk of the protein is completely degraded by the proteasome (reviewed in Briscoe and Therond, 2013). Both the processing and the degradation of GLI2 is dependent upon sequential phosphorylation of multiple serine residues by PKA, CK1 and GSK3, analagous to the requirement for these kinases in the processing of GLI3 (Pan et al, 2009; Pan et al, 2006; Pan and Wang, 2007). The differential processing of GLI2 and GLI3 depends on the processing determinant domain (PDD) in the C-terminal of the proteins, which directs the partial proteolysis of GLI3 in the absence of Hh signal. Substitution of 2 amino-acids from GLI3 into the GLI2 protein is sufficient to promote efficient processing of GLI2 to the repressor form (Pan and Wang, 2007)."
BMGC_PW1330,BMG_PW3871,,,"In the absence of Hh signaling, the majority of full-length GLI3 is partially processed by the proteasome to a shorter form that serves as the principal repressor of Hh target genes (Wang et al, 2000). Processing depends on phosphorylation at 6 sites by PKA, which primes the protein for subsequent phosphorylation at adjacent sites by CK1 and GSK3. The hyperphosphorylated protein is then a direct target for betaTrCP-dependent ubiquitination and proteasome-dependent processing (Wang and Li, 2006; Tempe et al, 2006; Wen et al, 2010; Schrader et al, 2011; Pan and Wang, 2007)."
BMGC_PW1331,BMG_PW3872,,,"Hedgehog is a secreted morphogen that has evolutionarily conserved roles in body organization by regulating the activity of the Ci/Gli transcription factor family. In Drosophila in the absence of Hh signaling, full-length Ci is partially degraded by the proteasome to generate a truncated repressor form that translocates to the nucleus to represses Hh-responsive genes. Binding of Hh ligand to the Patched (PTC) receptor allows the 7-pass transmembrane protein Smoothened (SMO) to be activated in an unknown manner, disrupting the partial proteolysis of Ci and allowing the full length activator form to accumulate (reviewed in Ingham et al, 2011; Briscoe and Therond, 2013). While many of the core components of Hh signaling are conserved from flies to humans, the pathways do show points of significant divergence. Notably, the human genome encodes three Ci homologues, GLI1, 2 and 3 that each play slightly different roles in regulating Hh responsive genes. GLI3 is the primary repressor of Hh signaling in vertebrates, and is converted to the truncated GLI3R repressor form in the absence of Hh. GLI2 is a potent activator of transcription in the presence of Hh but contributes only minimally to the repression function. While a minor fraction of GLI2 protein is processed into the repressor form in the absence of Hh, the majority is either fully degraded by the proteasome or sequestered in the full-length form in the cytosol by protein-protein interactions. GLI1 lacks the repression domain and appears to be an obligate transcriptional activator (reviewed in Briscoe and Therond, 2013). Vertebrate but not fly Hh signaling also depends on the movement of pathway components through the primary cilium. The primary cilium is a non-motile microtubule based structure whose construction and maintenance depends on intraflagellar transport (IFT). Anterograde IFT moves molecules from the ciliary base along the axoneme to the ciliary tip in a manner that requires the microtubule-plus-end directed kinesin KIF3 motor complex and the IFT-B protein complex, while retrograde IFT back to the ciliary base depends on the minus-end directed dynein motor and the IFT-A complex. Genetic screens have identified a number of cilia-related proteins that are required both to maintain Hh in the 'off' state and to transduce the signal when the pathway is activated (reviewed in Hui and Angers, 2011; Goetz and Anderson, 2010)."
BMGC_PW1332,BMG_PW3873,,,"In mammals, anterior Hox genes may be defined as paralog groups 1 to 4 (Natale et al. 2011), which are involved in development of the hindbrain through sequential expression in the rhombomeres, transient segments of the neural tube that form during development of the hindbrain (reviewed in Alexander et al. 2009, Soshnikova and Duboule 2009, Tumpel et al. 2009, Mallo et al. 2010, Andrey and Duboule 2014). Hox gene activation during mammalian development has been most thoroughly studied in mouse embryos and the results have been extended to human development by in vitro experiments with human embryonal carcinoma cells and human embryonic stem cells. Expression of a typical anterior Hox gene has an anterior boundary located at the junction between two rhombomeres and continues caudally to regulate segmentation and segmental fate in ectoderm, mesoderm, and endoderm. Anterior boundaries of expression of successive Hox paralog groups are generally separated from each other by 2 rhombomeres. For example, HOXB2 is expressed in rhombomere 3 (r3) and caudally while HOXB3 is expressed in r5 and caudally. Exceptions exist, however, as HOXA1, HOXA2, and HOXB1 do not follow the rule and HOXD1 and HOXC4 are not expressed in rhombomeres. Hox genes within a Hox cluster are expressed colinearly: the gene at the 3' end of the cluster is expressed earliest, and hence most anteriorly, then genes 5' are activated sequentially in the same order as they occur in the cluster. Activation of expression occurs epigenetically by loss of polycomb repressive complexes and change of bivalent chromatin to active chromatin through, in part, the actions of trithorax family proteins (reviewed in Soshnikova and Duboule 2009). Hox gene expression initiates in the posterior primitive streak that will contribute to extraembryonic mesoderm. Expression then extends anteriorly into the cells that will become the embryo, where expression is first observed in presumptive lateral plate mesoderm and is transmitted to both paraxial mesoderm and neurectoderm formed by gastrulation along the primitive streak (reviewed in Deschamps et al. 1999, Casaca et al. 2014). Prior to establishment of the rhombomeres, expression of HOXA1 and HOXB1 is initiated near the future site of r3 and caudally by a gradient of retinoic acid (RA). (Mechanisms of retinoic acid signaling are reviewed in Cunningham and Duester 2015.) The RA is generated by the ALDH1A2 (RALDH2) enzyme located in somites flanking the caudal hindbrain and degraded by CYP26 enzymes expressed initially in anterior neural ectoderm of the early gastrula and then throughout most of the hindbrain (reviewed in White and Schilling 2008). HOXA1 with PBX1,2 and MEIS2 directly activate transcription of ALDH1A2 to maintain retinoic acid synthesis in the somitic mesoderm (Vitobello et al. 2011). Differentiation of embryonal carcinoma cells and embryonic stem cells in response to retinoic acid is used to model the process of differentiation in vitro (reviewed in Soprano et al. 2007, Gudas et al. 2013). HOXA1 appears to set the anterior limit of HOXB1 expression (Barrow et al. 2000). HOXB1 initiates expression of EGR2 (KROX20) in presumptive r3. EGR2 then activates HOXA2 expression in r3 and r5 while HOXB1, together with PBX1 and MEIS:PKNOX1 (MEIS:PREP), activates expression of HOXA2 in r4 and caudal rhombomeres. AP-2 transcription factors maintain expression of HOXA2 in neural crest cells (Maconochie et al. 1999). HOXB1 also activates expression of HOXB2 in r3 and caudal rhombomeres. EGR2 negatively regulates HOXB1 so that by the time rhombomeres appear, HOXB1 is restricted to r4 and HOXA1 is no longer detectable (Barrow et al. 2000). EGR2 and MAFB (Kreisler) then activate HOXA3 and HOXB3 in r5 and caudal rhombomeres. Retinoic acid activates HOXA4, HOXB4, and HOXD4 in r7, the final rhombomere. HOX proteins, in turn, activate expression of genes in combination with other factors, notably members of the TALE family of transcription factors (PBX, PREP, and MEIS, reviewed in Schulte and Frank 2014, Rezsohazy et al. 2015). HOX proteins also participate in non-transcriptional interactions (reviewed in Rezsohazy 2014). In zebrafish, Xenopus, and chicken factors such as Meis3, Fgf3, Fgf8, and vHNF regulate anterior hox genes (reviewed in Schulte and Frank 2014), however less is known about the roles of homologous factors in mammals. Mutations in HOXA1 in humans have been observed to cause developmental abnormalities located mostly in the head and neck region (Tischfield et al. 2005, Bosley et al. 2008). A missense mutation in HOXA2 causes microtia, hearing impairment, and partially cleft palate (Alasti et al. 2008). A missense mutation in HOXB1 causes a similar phenotype to the Hoxb1 null mutation in mice: bilateral facial palsy, hearing loss, and strabismus (improper alignment of the eyes) (Webb et al. 2012)."
BMGC_PW1333,BMG_PW3874,,,"Cilia are membrane covered organelles that extend from the surface of eukaryotic cells. Cilia may be motile, such as respiratory cilia) or non-motile (such as the primary cilium) and are distinguished by the structure of their microtubule-based axonemes. The axoneme consists of nine peripheral doublet microtubules, and in the case of many motile cilia, may also contain a pair of central single microtubules. These are referred to as 9+0 or 9+2 axonemes, respectively. Relative to their non-motile counterparts, motile cilia also contain additional structures that contribute to motion, including inner and outer dynein arms, radial spokes and nexin links. Four main types of cilia have been identified in humans: 9+2 motile (such as respiratory cilia), 9+0 motile (nodal cilia), 9+2 non-motile (kinocilium of hair cells) and 9+0 non-motile (primary cilium and photoreceptor cells) (reviewed in Fliegauf et al, 2007). This pathway describes cilia formation, with an emphasis on the primary cilium. The primary cilium is a sensory organelle that is required for the transduction of numerous external signals such as growth factors, hormones and morphogens, and an intact primary cilium is needed for signaling pathways mediated by Hh, WNT, calcium, G-protein coupled receptors and receptor tyrosine kinases, among others (reviewed in Goetz and Anderson, 2010; Berbari et al, 2009; Nachury, 2014). Unlike the motile cilia, which are generally present in large numbers on epithelial cells and are responsible for sensory function as well as wave-like beating motions, the primary cilium is a non-motile sensory organelle that is present in a single copy at the apical surface of most quiescent cells (reviewed in Hsiao et al, 2012). Cilium biogenesis involves the anchoring of the basal body, a centriole-derived organelle, near the plasma membrane and the subsequent polymerization of the microtubule-based axoneme and extension of the plasma membrane (reviewed in Ishikawa and Marshall, 2011; Reiter et al, 2012). Although the ciliary membrane is continuous with the plasma membrane, the protein and lipid content of the cilium and the ciliary membrane are distinct from those of the bulk cytoplasm and plasma membrane (reviewed in Emmer et al, 2010; Rohatgi and Snell, 2010). This specialized compartment is established and maintained during cilium biogenesis by the formation of a ciliary transition zone, a proteinaceous structure that, with the transition fibres, anchors the basal body to the plasma membrane and acts as a ciliary pore to limit free diffusion from the cytosol to the cilium (reviewed in Nachury et al, 2010; Reiter et al, 2012). Ciliary components are targeted from the secretory system to the ciliary base and subsequently transported to the ciliary tip, where extension of the axoneme occurs, by a motor-driven process called intraflagellar transport (IFT). Anterograde transport of cargo from the ciliary base to the tip of the cilium requires kinesin-2 type motors, while the dynein-2 motor is required for retrograde transport back to the ciliary base. In addition, both anterograde and retrograde transport depend on the IFT complex, a multiprotein assembly consisting of two subcomplexes, IFT A and IFT B. The primary cilium is a dynamic structure that undergoes continuous steady-state turnover of tubulin at the tip; as a consequence, the IFT machinery is required for cilium maintenance as well as biogenesis (reviewed in Bhogaraju et al, 2013; Hsiao et al, 2012; Li et al, 2012; Taschner et al, 2012; Sung and Leroux, 2013). The importance of the cilium in signaling and cell biology is highlighted by the wide range of defects and disorders, collectively known as ciliopathies, that arise as the result of mutations in genes encoding components of the ciliary machinery (reviewed in Goetz and Anderson, 2010; Madhivanan and Aguilar, 2014)."
BMGC_PW1334,BMG_PW3913,,,"The ATP-binding cassette (ABC) transporters form a large family of transmembrane proteins that utilise the energy from the hydrolysis of ATP to facilitate the movement of a wide variety of substrates against a concentration gradient across membrane bilayers. Substrates include amino acids, lipids, inorganic ions, peptides, saccharides, peptides for antigen presentation, metals, drugs, and proteins. Of the 48 known ABC transporters in humans, 15 are associated with a defined human disease (Tarling et al. 2013, Woodward et al. 2011, Dean 2005, Kemp et al. 2011, Ueda 2011, Chen & Tiwari 2011)."
BMGC_PW1335,BMG_PW3924,,,"Arginine vasopressin (AVP(20-28)) is a 9 amino-acid long signal peptide produced by cleavage of the precursor protein AVP in the hypothalamus. It mediates the reabsorption of water in the kidney and its synthesis and release are physiologically regulated by plasma osmolarity, blood pressure and/or blood volume. AVP(20-28) binds to vasopressin receptors AVPR1 and 2, located on the basolateral surface of the kidney collecting duct. This binding results in interaction of AVPRs with the G protein alpha-s. Following a cascade of downstream events, ultimately the water channel aquaporin 2 (AQP2) translocates from intracellular stores to the apical surface where it functions as the entry site for water reabsorption. When water balance is achieved, plasma levels of AVP(20-28) drop and AQP2 levels in the apical plasma membrane are decreased. Mutations in AVP make it unavailable to its AVPRs in the kidney, resulting in dysregulation of water reabsorption. This can cause familial neurohypophyseal diabetes insipidus (FNDI), an autosomal dominant disorder characterised by persistent excessive thirst resulting in constant drinking (polydipsia) and passage of large volumes of urine (polyuria). In FNDI, the production and release of AVP from the posterior pituitary gland is impaired (Moeller et al. 2013)."
BMGC_PW1336,BMG_PW3926,,,"The solute-carrier gene (SLC) superfamily encodes membrane-bound transporters comprising 55 gene families with at least 362 putatively functional protein-coding genes. The gene products include passive transporters, symporters and antiporters and are located in all cellular and organelle membranes. Curated here is a list of SLCs, where mutations within them can result in disease (Hediger et al. 2013)."
BMGC_PW1337,BMG_PW3935,,,"Proteins with transporting functions can be roughly classified into 3 categories: ATP hydrolysis-coupled pumps, ion channels, and transporters. Pumps utilize the energy released by ATP hydrolysis to power the movement of substrates across the membrane against their electrochemical gradient. Channels in their open state can transfer substrates (ions or water) down their electrochemical gradient at an extremely high efficiency (up to 108 s-1). Transporters facilitate the movement of a specific substrate either against or with their concentration gradient at a lower speed (about 102 -104 s-1); as generally believed, conformational change of the transporter protein is involved in the transfer process. Diseases caused by defects in these transporter proteins are detailed in this section. Disorders associated with ABC transporters and SLC transporters are annotated here (Dean 2005)."
BMGC_PW1338,BMG_PW3936,,,"Hox genes encode proteins that contain the DNA-binding homeobox motif and control early patterning of segments in the embryo as well as later events in development (reviewed in Rezsohazy et al. 2015). Mammals have 39 Hox genes arrayed in 4 linear clusters, with each cluster containing 9 to 11 genes. Based on homologies, the genes have been assigned to 13 paralogous groups. The nomenclature of Hox genes uses a letter to indicate the cluster and a number to indicate the paralog group. For example, HOXA4 is the gene in cluster A that is most similar with genes of paralog group 4 from other clusters. One of the most striking aspects of mammalian Hox gene function is the mechanism of their activation during embryogenesis: the order of genes in a cluster correlates with the timing and location of their activation such that genes at the 3' end of a cluster are activated first and genes at the 5' end of a cluster are activated last. (5' and 3' refer to the transcriptional orientation of the genes in the cluster.) Because development of segments of the embryo proceeds from anterior to posterior this means that the anterior boundaries of expression of 3' genes are more anterior (rostral) and the anterior boundaries of expression of 5' genes are more posterior (caudal). Expression of HOX genes initiates in the posterior primitive streak at the beginning of gastrulation at approximately E7.5 in mouse. As gastrulation proceeds, further 5' genes are sequentially activated and they too undergo the same chromatin changes and migration. After formation of the axis of the embryo, similar waves of activation of HOXA and HOXD clusters occur in developing limbs beginning at about E9. Retinoids, especially all trans retinoic acid (atRA), participate in initiating the process via retinoid receptors. Other factors such as FGFs and Wnt, also regulate Hox expression. After activation, Hox genes participate in maintaining their own expression (autoregulation), activating later, 5' Hox genes, and repressing prior, 3' Hox genes (crossregulation). Differentiation of embryonal carcinoma cells and embryonic stem cells in response to retinoic acid is used to model the process in vitro (reviewed in Gudas et al. 2013). Activation of Hox genes is accompanied by a change from bivalent chromatin to euchromatin (reviewed in Soshnikova and Duboule 2009). Bivalent chromatin has extensive methylation of lysine-9 on histone H3 (H3K9me3), a repressive mark, with interspersed punctate regions of methylation of lysine-4 on histone H3 (H3K4me2, H3K4me3), an activating mark. Euchromatization initiates at the 3' ends of clusters and proceeds towards the 5' ends, with the euchromatin migrating to an active region of the nucleus (reviewed in Montavon and Duboule 2013). This change in chromatin reflects a loss of H3K27me3 and a gain of H3K4me2,3. Polycomb repressive complexes bind H3K27me3 and are responsible for maintenance of repression, KDM6A and KDM6B histone demethylases remove H3K27me3, and members of the trithorax family of histone methylases (KMT2A, KMT2C, KMT2D) methylate H3K4."
BMGC_PW1339,BMG_PW3937,,,"Cilium biogenesis is initiated by the docking of basal bodies, a centriole-derived organelle, to the plasma membrane (reviewed in Reiter et al, 2012). The centriole consists of a multiprotein core surrounded by a ring of nine microtubule triplets; the mother centriole additionally has 'distal' and 'subdistal appendages' that are critical for ciliogenesis (reviewed in Kim and Dynlacht, 2013; Firat-Karalar and Stearns, 2014; Bettencourt-Dias et al, 2011). Basal bodies initiate and anchor the extension of the axonemal microtubules and also associate with secretory vesicles which are thought to provide membrane components for the extension of the ciliary membrane (Sorokin, 1962; Sorokin, 1968; Bachmann-Gagescu et al, 2011; Tanos et al, 2013; reviewed in Ishikawa et al, 2011; Reiter et al, 2012). Basal bodies are attached to the plasma membrane through a proteinaceous network of transition fibers that form part of the 'transition zone' at the ciliary base. The transition zone acts as a selective barrier or ciliary pore, excluding vesicles and limiting the diffusion of proteins and lipids from the cytosol or plasma membrane (Deane et al, 2001; Craige et al, 2010; Garcia-Gonzalo et al, 2011; Ye et al, 2014; Joo et al, 2013; reviewed in Nachury et al, 2010; Hsiao et al, 2012; Reiter et al, 2012). In addition to the transition fibres, the transition zone also consists of the ciliary necklace (a row of protein particles at the ciliary membrane at the base of the cilium) and the Y-links (that connect the axonemal microtubules to the membrane at the ciliary necklace) (Williams et al, 2011; reviewed in Hsiao et al, 2012; Reiter et al, 2012)."
BMGC_PW1340,BMG_PW3938,,,"A number of membrane proteins destined for the ciliary membrane are recognized by ARF4 in the trans-Golgi network, initiating the formation of a ciliary targeting complex that directs the passage of these cargo to the cilium (Mazelova et al, 2009; Geng et al, 2006; Jenkins et al, 2006; Ward et al, 2011; reviewed in Deretic, 2013). Although there is some support for the presence of a VxPx or related motif in the C-terminal tail of cargo destined for ARF4-mediated transport to the cilium, the details of this have not been definitively established and other ciliary targeting sequences have also been identified (reviewed in Deretic, 2013; Bhogaraju et al, 2013)."
BMGC_PW1341,BMG_PW3939,,,"Proteomic studies suggest that the cilium is home to approximately a thousand proteins, and has a unique protein and lipid make up relative to the bulk cytoplasm and plasma membrane (Pazour et al, 2005; Ishikawa et al, 2012; Ostrowoski et al, 2002; reviewed in Emmer et al, 2010; Rohatgi and Snell, 2010). In addition, the cilium is a dynamic structure, and the axoneme is continually being remodeled by addition and removal of tubulin at the distal tip (Marshall and Rosenbaum, 2001; Stephens, 1997; Song et al, 2001). As a result, the function and structure of this organelle relies on the directed trafficking of protein and vesicles to the cilium. Small GTPases of the RAS, RAB, ARF and ARL families are involved in cytoskeletal organization and membrane traffic and are required to regulate the traffic from the Golgi and the trans-Golgi network to the cilium (reviewed in Deretic, 2013; Li et al, 2012). ARF4 is a Golgi-resident GTPase that acts in conjunction with a ciliary-targeting complex consisting of the ARF-GAP ASAP1, RAB11A, the RAB11 effector FIP3 and the RAB8A guanine nucleotide exchange factor RAB3IP/RABIN8 to target cargo bearing a putative C-terminal VxPx targeting motif to the cilium. A well-studied example of this system involves the trafficking of rhodopsin to the retinal rod photoreceptors, a specialized form of the cilium (reviewed in Deretic, 2013). ARL3, ARL13B and ARL6 are all small ARF-like GTPases with assorted roles in ciliary trafficking and maintenance. Studies in C. elegans suggest that ARL3 and ARL13B have opposing roles in maintaining the stability of the anterograde IFT trains in the cilium (Li et al, 2010). In addition, both ARL3 and ARL13B have roles in facilitating the traffic of subsets of ciliary cargo to the cilium. Myristoylated cargo such as peripheral membrane protein Nephrocystin-3 (NPHP3) is targeted to the cilium in a UNC119- and ARL3-dependent manner, while ARL13B is required for the PDE6-dependent ciliary localization of INPP5E (Wright et al, 2011; Humbert et al, 2012; reviewed in Li et al, 2012). ARL6 was also identified as BBS3, a gene that when mutated gives rise to the ciliopathy Bardet-Biedl syndrome (BBS). ARL6 acts upstream of a complex of 8 other BBS-associated proteins known as the BBSome. ARL6 and the BBSome are required for the ciliary targeting of proteins including the melanin concentrating hormone receptor (MCHR) and the somatostatin receptor (SSTR3), among others (Nachury et al, 2007; Loktev et al, 2008; Jin et al, 2010; Zhang et al, 2011). Both the BBSome and ARL6 may continue to be associated with cargo inside the cilium, as they are observed to undergo typical IFT movements along the axoneme (Fan et al, 2004; Lechtreck et al, 2009; reviewed in Li et al, 2012)."
BMGC_PW1342,BMG_PW3940,,,"The BBSome is a stable complex consisting of 7 Bardet-Biedl proteins (BBS1, 2, 4, 5, 7, 8 and 9) and BBIP10 that has roles in promoting IFT and trafficking proteins to the cilum (Blacque et al, 2004; Nachury et al, 2007; Loktev et al, 2008; Jin et al, 2010; reviewed in Sung and Leroux 2013). The BBSome is the primary effector of ARL6/BBS3, a small GTPase that binds the BBSome in complex with associated membrane proteins that are destined for the ciliary membrane (Jin et al, 2010; Nachury et al, 2007; Zhang et al, 2011; Seo et al, 2011). Components of the BBSome are enriched in TPR and beta-propeller motifs and are thought to form a linear coat on membranes that functions with ARL6 to target proteins to the cilium (Jin et al, 2010; reviewed in Nachury et al, 2010)."
BMGC_PW1343,BMG_PW3941,,,"Intraflagellar transport (IFT) is a motor-based process that controls the anterograde and retrograde transport of large protein complexes, ciliary cargo and structural components along the ciliary axoneme (reviewed in Cole and Snell, 2009). IFT particles contain two multiprotein IFT subcomplexes, IFT A and IFT B, with ~6 and ~15 subunits, respectively. Linear arrays of IFT A and IFT B 'trains' assemble at the ciliary base along with the active plus-end directed kinesin-2 motors and the inactive dynein motors and traffic along the microtubules at a rate of ~2 micrometers per second. At the ciliary tip, the IFT trains disassemble, releasing cargo and motors, and smaller IFT trains are subsequently reassembled for retrograde traffic driven by the now active minus-end directed dynein-2 motors. Retrograde trains travel down the length of the axoneme at a rate of ~3 micrometers per second and are disassembled and recycled for further rounds of transport at the ciliary base (reviewed in Taschner et al, 2012; Bhogaraju et al, 2013; Ishikawa et al, 2011). Mutations in kinesin-2 motors or IFT B complex members tend to abrogate cilium formation, while mutations in dynein-2 motor or in IFT A complex members generally result in short, bulging cilia that abnormally accumulate IFT particles. These observations are consistent with a primary role for IFT B and IFT A complexes in anterograde and retrograde transport, respectively (see for instance, Huangfu et al, 2005; Follit et al, 2006; May et al, 2005; Tran et al, 2008; reviwed in Ishikawa et al, 2011). In addition to the IFT A and B complexes, the IFT particles may also contain the multi-protein BBSome complex, which displays typical IFT-like movement along the ciliary axoneme and which is required for cilium biogenesis and delivery and transport of some ciliary cargo (Blaque et al, 2004; Nachury et al, 2007; Ou et al, 2005; Ou et al, 2007; reviewed in Sung and Leroux, 2013; Bhorgaraju et al, 2013)."
BMGC_PW1344,BMG_PW3942,,,"Dendritic cell-associated C-type lectin-2 (Dectin-2) family of C-type lectin receptors (CLRs) includes Dectin-2 (CLEC6A), blood dendritic antigen 2 (BDCA2/CLEC4C), macrophage C-type lectin (MCL/CLEC4D), Dendritic cell immunoreceptor (DCIR/CLEC4A) and macrophage inducible C-type lectin (Mincle/CLEC4E). These receptors possesses a single extracellular conserved C-type lectin domain (CTLD) with a short cytoplasmic tail that induces intracellular signalling indirectly by binding with the FCERG (High affinity immunoglobulin epsilon receptor subunit gamma) except for DCIR that has a longer cytoplasmic tail with an integral inhibitory signalling motif (Graham & Brown. 2009, Kerschera et al. 2013). CLEC6A (Dectin-2) binds to high mannose containing pathogen-associated molecular patterns (PAMPs) expressed by fungal hyphae, and CLEC4E (mincle) binds to alpha-mannaosyl PAMPs on fungal, mycobacterial and necrotic cell ligands. Both signaling pathways lead to Toll-like receptor (TLR)-independent production of cytokines such as tumor necrosis factor (TNF) and interleukin 6 (IL6). Similarities with Dectin-1 (CLC7A) signaling pathway suggests that both these CLRs couple SYK activation to NF-kB activation using a complex involving CARD9, BCL10 and MALT1 (Geijtenbeek & Gringhuis 2009)."
BMGC_PW1345,BMG_PW3943,,,"Pathogen recognition is central to the induction of T cell differentiation. Groups of pathogens share similar structures known as pathogen-associated molecular patterns (PAMPs), which are recognised by pattern recognition receptors (PRRs) expressed on dendritic cells (DCs) to induce cytokine expression. PRRs include archetypical Toll-like receptors (TLRs) and non-TLRs such as retinoic acid-inducible gene I (RIG-I)-like receptors, C-type lectin receptors (CLRs) and intracellular nucleotide-binding domain and leucine-rich-repeat-containing family (NLRs). PRR recognition of PAMPs can lead to the activation of intracellular signalling pathways that elicit innate responses against pathogens and direct the development of adaptive immunity. CLRs comprises a large family of receptors which bind carbohydrates, through one or more carbohydrate recognition domains (CRDs), or which possess structurally similar C-type lectin-like domains (CTLDs) which do not necessarily recognise carbohydrate ligands. Some CLRs can induce signalling pathways that directly activate nuclear factor-kB (NF-kB), whereas other CLRs affect signalling by Toll-like receptors. These signalling pathways trigger cellular responses, including phagocytosis, DC maturation, chemotaxis, the respiratory burst, inflammasome activation, and cytokine production."
BMGC_PW1346,BMG_PW3944,,,"CD209 (also called as DC-SIGN (DC-specific intracellular adhesion molecule-3-grabbing non-integrin)) is a type II transmembrane C-type lectin receptor preferentially expressed on dendritic cells (DCs). CD209 functions as a pattern recognition receptor (PRR) that recognises several microorganisms and pathogens, contributing to generation of pathogen-tailored immune responses (Gringhuis & Geijtenbeek 2010, den Dunnen et al. 2009, Svajger et al. 2010). CD209 interacts with different mannose-expressing pathogens such as Mycobacterium tuberculosis and HIV-1 (Gringhuis et al. 2007, Geijtenbeek et al. 2000a). It also acts as an adhesion receptor that interacts with ICAM2 (intracellular adhesion molecule-2) on endothelial cells and ICAM3 on T cells (Geijtenbeek et al. 2000b,c). CD209 functions not only as an independent PRR, but is also implicated in the modulation of Toll-like receptor (TLR) signaling at the level of the transcription factor NF-kB (Gringhuis et al. 2009). CLEC7A (Dectin-1) and CD209 (DC-SIGN) signalling modulates Toll-like receptor (TLR) signalling through the kinase RAF1 that is independent of the SYK pathway but integrated with it at the level of NF-kB activation. The activation of RAF1 by CLEC7A or CD209 does not lead to activation of extracellular signal-regulated kinase 1 (ERK1)/2 or Mitogen-activated protein kinase kinase 1 (MEK1)/2 but leads to the phosphorylation and subsequent acetylation of RELA (p65). RELA phosphorylated on S276 not only positively regulates the activity of p65 through acetylation of p65, but also represses RELB activity by sequestering active RELB into inactive p65-RELB dimers that do not bind DNA (Gringhuis et al. 2007, Svajger et al. 2010, Jacque et al. 2005). RAF1-dependent signaling pathway is crucial in dectin-1 mediated immunity as it modulates both the canonical (promoting p65 phosphorylation and acetylation) and non-canonical (forming inactive p65-RELB dimers) NK-kB activation."
BMGC_PW1347,BMG_PW3947,,,"Protein kinases N (PKN), also known as protein kinase C-related kinases (PKR) feature a C-terminal serine/threonine kinase domain and three RHO-binding motifs at the N-terminus. RHO GTPases RHOA, RHOB, RHOC and RAC1 bind PKN1, PKN2 and PKN3 (Maesaki et al. 1999, Zhong et al. 1999, Owen et al. 2003, Modha et al. 2008, Hutchinson et al. 2011, Hutchinson et al. 2013), bringing them in proximity to the PIP3-activated co-activator PDPK1 (PDK1) (Flynn et al. 2000, Torbett et al. 2003). PDPK1 phosphorylates PKNs on a highly conserved threonine residue in the kinase activation loop, which is a prerequisite for PKN activation. Phosphorylation of other residues might also be involved in activation (Flynn et al. 2000, Torbett et al. 2003, Dettori et al. 2009). PKNs are activated by fatty acids like arachidonic acid and phospholipids in vitro, but the in vivo significance of this activation remains unclear (Palmer et al. 1995, Yoshinaga et al. 1999). PKNs play important roles in diverse functions, including regulation of cell cycle, receptor trafficking, vesicle transport and apoptosis. PKN is also involved in the ligand-dependent transcriptional activation by the androgen receptor. More than 20 proteins and several peptides have been shown to be phosphorylated by PKN1 and PKN2, including CPI-17 (Hamaguchi et al. 2000), alpha-actinin (Mukai et al. 1997), adducin (Collazos et al. 2011), CDC25C (Misaki et al. 2001), vimentin (Matsuzawa et al. 1997), TRAF1 (Kato et al. 2008), CLIP170 (Collazos et al. 2011) and EGFR (Collazos et al. 2011). There are no known substrates for PKN3 (Collazos et al. 2011)."
BMGC_PW1348,BMG_PW3948,,,"PKN1, activated by phosphorylation at threonine T774, binds activated AR (androgen receptor) and promotes transcription from AR-regulated promoters. On one hand, phosphorylated PKN1 promotes the formation of a functional complex of AR with the transcriptional coactivator NCOA2 (TIF2) (Metzger et al. 2003). On the other hand, binding of phosphorylated PKN1, in complex with the activated AR, to androgen-reponsive promoters of KLK2 and KLK3 (PSA) genes, leads to PKN1-mediated histone phosphorylation. PKN1-phosphorylated histones recruit histone demethylases KDM4C (JMJD2C) and KDM1A (LSD1), and the ensuing demethylation of histones associated with the promoter regions of KLK2 and KLK3 genes increases their transcription (Metzger et al. 2005, Metzger et al. 2008)."
BMGC_PW1349,BMG_PW3949,,,"Citron kinase (CIT) or citron RHO-interacting kinase (CRIK) shares similarities with ROCK kinases. Like ROCK, it consists of a serine/threonine kinase domain, a coiled-coil region, a RHO-binding domain, a cysteine rich region and a plekstrin homology (PH) domain, but additionally features a proline-rich region and a PDZ-binding domain. A shorter splicing isoform of CIT, citron-N, is specifically expressed in the nervous system and lacks the kinase domain. Citron-N is a component of the post-synaptic density, where it binds to the PDZ domains of the scaffolding protein PDS-95/SAP90 (Zhang et al. 2006). While the binding of CIT to RHO GTPases RHOA, RHOB, RHOC and RAC1 is well established (Madaule et al. 1995), the mechanism of CIT activation by GTP-bound RHO GTPases has not been elucidated. There are indications that CIT may be activated through autophosphorylation in the presence of active forms of RHO GTPases (Di Cunto et al. 1998). CIT appears to phosphorylate the myosin regulatory light chain (MRLC), the only substrate identified to date, on the same residues that are phosphorylated by ROCKs, but it has not been established yet how this relates to activation by RHO GTPases (Yamashiro et al. 2003). CIT and RHOA are implicated to act together in Golgi apparatus organization through regulation of the actin cytoskeleton (Camera et al. 2003). CIT is also involved in the regulation of cytokinesis through its interaction with KIF14 (Gruneberg et al. 2006, Bassi et al. 2013, Watanabe et al. 2013) and p27(Kip1) (Serres et al. 2012)."
BMGC_PW1350,BMG_PW3950,,,"GTP-bound active forms of RHO GTPases RHOA, RHOG, RAC1 and CDC42 bind kinectin (KTN1), a protein inserted in endoplasmic reticulum membranes that interacts with the cargo-binding site of kinesin and activates its microtubule-stimulated ATPase activity required for vesicle motility (Vignal et al. 2001, Hotta et al. 1996). The effect of RHOG activity on cellular morphology, exhibited in the formation of microtubule-dependent cellular protrusions, depends both on RHOG interaction with KTN1, as well as on the kinesin activity (Vignal et al. 2001). RHOG and KTN1 also cooperate in microtubule-dependent lysosomal transport (Vignal et al. 2001). The precise mechanism of kinectin-mediated Rho GTPase signaling cascade needs further elucidation, and only the first two steps, KTN1-activated RHO GTPase binding, and KTN1-kinesin-1 binding are annotated here."
BMGC_PW1351,BMG_PW3951,,,"IQGAPs constitute a family of scaffolding proteins characterized by a calponin homology (CH) domain, a polyproline binding region (WW domain), a tandem of four IQ (isoleucine and glutamine-rich) repeats and a RAS GTPase-activating protein-related domain (GRD). Three IQGAPs have been identified in human, IQGAP1, IQGAP2 and IQGAP3. The best characterized is IQGAP1 and over 90 proteins have been reported to bind to it. IQGAPs integrate multiple signaling pathways and coordinate a large variety of cellular activities (White et al. 2012). IQGAP proteins IQGAP1, IQGAP2 and IQGAP3, bind activated RHO GTPases RAC1 and CDC42 via their GRD and stabilize them in their GTP-bound state (Kuroda et al. 1996, Swart-Mataraza et al. 2002, Wang et al. 2007). IQGAPs bind F-actin filaments via the CH domain and modulate cell shape and motility through regulation of G-actin/F-actin equilibrium (Brill et al. 1996, Fukata et al. 1997, Bashour et al. 1997, Wang et al. 2007, Pelikan-Conchaudron et al. 2011). Binding of IQGAPs to F-actin is inhibited by calmodulin binding to the IQ repeats (Bashour et al. 1997, Pelikan-Conchaudron et al. 2011). Based on IQGAP1 studies, IQGAPs presumably function as homodimers (Bashour et al. 1997). IQGAP1 is involved in the regulation of adherens junctions through its interaction with E-cadherin (CDH1) and catenins (CTTNB1 and CTTNA1) (Kuroda et al. 1998, Hage et al. 2009). IQGAP1 contributes to cell polarity and lamellipodia formation through its interaction with microtubules (Fukata et al. 2002, Suzuki and Takahashi 2008)."
BMGC_PW1352,BMG_PW3952,,,"TNF-alpha activates sphingomyelinase (SMASE) proteins to catalyze hydrolysis of sphingomyeline into ceramide. Two types of SMASE can be distinguished downstream of TNFR1 signaling, acid and neutral SMASEs (Adam-Klages S et al. 1996, 1998). Neutral SMASE (such as SMPD2,3) has a pH optimum of 7.4, requires Mg2+ ions and is found at the plasma membrane (Rao BG and Spence MW 1976). Acid SMASE is active at pH 4-5, is Zn2+-dependent and is mainly localized in the lysosomes. The death domain of TNFR1 that is responsible for the initiation of the apoptotic pathway also mediates activation of an acid SMASE. The two proapoptotic adaptor proteins TRADD and FADD are also involved in the activation of acid SMASE signaling events (Schwandner R et al. 1998). TNF-alpha can also activate the pro-apoptotic acidic SMASE via caspase-8 mediated activation of caspase-7 which in turn proteolytically cleaves and activates the 72kDa pro-acid SMASE form (Edelmann B et al. 2011). Neutral SMASE(SMPD) binds to adaptor protein NSMAF (FAN), which bridges it to NSMASE-activating domain (NSD) of TNFR1 (Adam D et al. 1996; Adam-Klages S et al. 1996; Ségui B et al. 2001). Activation of SMPD2,3 leads to an accumulation of ceramide at the cell surface. Ceramide metabolism generates a cascade of bioactive lipids, all of which carry a specific signaling capacity. Ceramide can be converted by ceramidase into sphingosine, which in turn is phosphorylated by sphingosine kinase into sphingosine-1-phosphate (S1P). These lipids exert opposite biological effects: ceramide and sphingosine are able to induce anti-proliferative and pro-apoptotic responses, whereas S1P is a cytoprotective molecule that promotes cell growth and counteracts apoptotic stimuli (Cuvillier O et al.1996)"
BMGC_PW1353,BMG_PW3954,,,"RHO associated, coiled-coil containing protein kinases ROCK1 and ROCK2 consist of a serine/threonine kinase domain, a coiled-coil region, a RHO-binding domain and a plekstrin homology (PH) domain interspersed with a cysteine-rich region. The PH domain inhibits the kinase activity of ROCKs by an intramolecular fold. ROCKs are activated by binding of the GTP-bound RHO GTPases RHOA, RHOB and RHOC to the RHO binding domain of ROCKs (Ishizaki et al. 1996, Leung et al. 1996), which disrupts the autoinhibitory fold. Once activated, ROCK1 and ROCK2 phosphorylate target proteins, many of which are involved in the stabilization of actin filaments and generation of actin-myosin contractile force. ROCKs phosphorylate LIM kinases LIMK1 and LIMK2, enabling LIMKs to phosphorylate cofilin, an actin depolymerizing factor, and thereby regulate the reorganization of the actin cytoskeleton (Ohashi et al. 2000, Sumi et al. 2001). ROCKs phosphorylate MRLC (myosin regulatory light chain), which stimulates the activity of non-muscle myosin II (NMM2), an actin-based motor protein involved in cell migration, polarity formation and cytokinesis (Amano et al. 1996, Riento and Ridley 2003, Watanabe et al. 2007, Amano et al. 2010). ROCKs also phosphorylate the myosin phosphatase targeting subunit (MYPT1) of MLC phosphatase, inhibiting the phosphatase activity and preventing dephosphorylation of MRLC. This pathway acts synergistically with phosphorylation of MRLC by ROCKs towards stimulation of non-muscle myosin II activity (Kimura et al. 1996, Amano et al. 2010)."
BMGC_PW1354,BMG_PW3955,,,"The PAKs (p21-activated kinases) are a family of serine/threonine kinases mainly implicated in cytoskeletal rearrangements. All PAKs share a conserved catalytic domain located at the carboxyl terminus and a highly conserved motif in the amino terminus known as p21-binding domain (PBD) or Cdc42/Rac interactive binding (CRIB) domain. There are six mammalian PAKs that can be divided into two classes: class I (or conventional) PAKs (PAK1-3) and class II PAKs (PAK4-6). Conventional PAKs are important regulators of cytoskeletal dynamics and cell motility and are additionally implicated in transcription through MAPK (mitogen-activated protein kinase) cascades, death and survival signaling and cell cycle progression (Chan and Manser 2012). PAK1, PAK2 and PAK3 are direct effectors of RAC1 and CDC42 GTPases. RAC1 and CDC42 bind to the CRIB domain. This binding induces a conformational change that disrupts inactive PAK homodimers and relieves autoinhibition of the catalytic carboxyl terminal domain (Manser et al. 1994, Manser et al. 1995, Zhang et al. 1998, Lei et al. 2000, Parrini et al. 2002; reviewed by Daniels and Bokoch 1999, Szczepanowska 2009). Autophosphorylation of a conserved threonine residue in the catalytic domain of PAKs (T423 in PAK1, T402 in PAK2 and T436 in PAK3) is necessary for the kinase activity of PAK1, PAK2 and PAK3. Autophosphorylation of PAK1 serine residue S144, PAK2 serine residue S141, and PAK3 serine residue S154 disrupts association of PAKs with RAC1 or CDC42 and enhances kinase activity (Lei et al. 2000, Chong et al. 2001, Parrini et al. 2002, Jung and Traugh 2005, Wang et al. 2011). LIMK1 is one of the downstream targets of PAK1 and is activated through PAK1-mediated phosphorylation of the threonine residue T508 within its activation loop (Edwards et al. 1999). Further targets are the myosin regulatory light chain (MRLC), myosin light chain kinase (MLCK), filamin, cortactin, p41Arc (a subunit of the Arp2/3 complex), caldesmon, paxillin and RhoGDI, to mention a few (Szczepanowska 2009). Class II PAKs also have a CRIB domain, but lack a defined autoinhibitory domain and proline-rich regions. They do not require GTPases for their kinase activity, but their interaction with RAC or CDC42 affects their subcellular localization. Only conventional PAKs will be annotated here."
BMGC_PW1355,BMG_PW3956,,,"While the p53 tumor suppressor protein (TP53) is known to inhibit cell growth by inducing apoptosis, senescence and cell cycle arrest, recent studies have found that p53 is also able to influence cell metabolism to prevent tumor development. TP53 regulates transcription of many genes involved in the metabolism of carbohydrates, nucleotides and amino acids, protein synthesis and aerobic respiration. TP53 stimulates transcription of TIGAR, a D-fructose 2,6-bisphosphatase. TIGAR activity decreases glycolytic rate and lowers ROS (reactive oxygen species) levels in cells (Bensaad et al. 2006). TP53 may also negatively regulate the rate of glycolysis by inhibiting the expression of glucose transporters GLUT1, GLUT3 and GLUT4 (Kondoh et al. 2005, Schwartzenberg-Bar-Yoseph et al. 2004, Kawauchi et al. 2008). TP53 negatively regulates several key points in PI3K/AKT signaling and downstream mTOR signaling, decreasing the rate of protein synthesis and, hence, cellular growth. TP53 directly stimulates transcription of the tumor suppressor PTEN, which acts to inhibit PI3K-mediated activation of AKT (Stambolic et al. 2001). TP53 stimulates transcription of sestrin genes, SESN1, SESN2, and SESN3 (Velasco-Miguel et al. 1999, Budanov et al. 2002, Brynczka et al. 2007). One of sestrin functions may be to reduce and reactivate overoxidized peroxiredoxin PRDX1, thereby reducing ROS levels (Budanov et al. 2004, Papadia et al. 2008, Essler et al. 2009). Another function of sestrins is to bind the activated AMPK complex and protect it from AKT-mediated inactivation. By enhancing AMPK activity, sestrins negatively regulate mTOR signaling (Budanov and Karin 2008, Cam et al. 2014). The expression of DDIT4 (REDD1), another negative regulator of mTOR signaling, is directly stimulated by TP63 and TP53. DDIT4 prevents AKT-mediated inactivation of TSC1:TSC2 complex, thus inhibiting mTOR cascade (Cam et al. 2014, Ellisen et al. 2002, DeYoung et al. 2008). TP53 may also be involved, directly or indirectly, in regulation of expression of other participants of PI3K/AKT/mTOR signaling, such as PIK3CA (Singh et al. 2002), TSC2 and AMPKB (Feng et al. 2007). TP53 regulates mitochondrial metabolism through several routes. TP53 stimulates transcription of SCO2 gene, which encodes a mitochondrial cytochrome c oxidase assembly protein (Matoba et al. 2006). TP53 stimulates transcription of RRM2B gene, which encodes a subunit of the ribonucleotide reductase complex, responsible for the conversion of ribonucleotides to deoxyribonucleotides and essential for the maintenance of mitochondrial DNA content in the cell (Tanaka et al. 2000, Bourdon et al. 2007, Kulawiec et al. 2009). TP53 also transactivates mitochondrial transcription factor A (TFAM), a nuclear-encoded gene important for mitochondrial DNA (mtDNA) transcription and maintenance (Park et al. 2009). Finally, TP53 stimulates transcription of the mitochondrial glutaminase GLS2, leading to increased mitochondrial respiration rate and reduced ROS levels (Hu et al. 2010). The great majority of tumor cells generate energy through aerobic glycolysis, rather than the much more efficient aerobic mitochondrial respiration, and this metabolic change is known as the Warburg effect (Warburg 1956). Since the majority of tumor cells have impaired TP53 function, and TP53 regulates a number of genes involved in glycolysis and mitochondrial respiration, it is likely that TP53 inactivation plays an important role in the metabolic derangement of cancer cells such as the Warburg effect and the concomitant increased tumorigenicity (reviewed by Feng and Levine 2010). On the other hand, some mutations of TP53 in Li-Fraumeni syndrome may result in the retention of its wild-type metabolic activities while losing cell cycle and apoptosis functions (Wang et al. 2013). Consistent with such human data, some mutations of p53, unlike p53 null state, retain the ability to regulate energy metabolism while being inactive in regulating its classic gene targets involved in cell cycle, apoptosis and senescence. Retention of metabolic and antioxidant functions of p53 protects p53 mutant mice from early onset tumorigenesis (Li et al. 2012)."
BMGC_PW1356,BMG_PW3957,,,"Repression of Hh signaling in the absence of ligand depends on the transmembrane receptor protein Patched (PTCH), which inhibits Smoothened (SMO) activity by an unknown mechanism. This promotes the proteolytic processing and/or degradation of the GLI family of transcription factors and maintains the pathway in a transcriptionally repressed state (reviewed in Briscoe and Therond, 2013). In the absence of ligand, PTCH is localized in the cilium, while SMO is largely concentrated in intracellular compartments. Upon binding of Hh to the PTCH receptor, PTCH is endocytosed, relieving SMO inhibition and allowing it to accumulate in the primary cilium (Marigo et al, 1996; Chen and Struhl, 1996; Stone et al, 1996; Rohatgi et al, 2007; Corbit et al, 2005; reviewed in Goetz and Anderson, 2010). In the cilium, SMO is activated by an unknown mechanism, allowing the full length transcriptional activator forms of the GLI proteins to accumulate and translocate to the nucleus, where they bind to the promoters of Hh-responsive genes (reviewed in Briscoe and Therond, 2013). In addition to PTCH, three additional membrane proteins have been shown to bind Hh and to be required for Hh-dependent signaling in vertebrates: CDON (CAM-related/downregulated by oncogenes), BOC (brother of CDO) and GAS1 (growth arrest specific 1) (Yao et al, 2006; Okada et al, 2006; Tenzen et al, 2006; McLellan et al, 2008; reviewed in Kang et al, 2007; Beachy et al, 2010; Sanchez-Arrones et al, 2012). CDON and BOC, homologues of Drosophila Ihog and Boi respectively, are evolutionarily conserved transmembrane glycoproteins that have been shown to bind both to Hh ligand and to the canonical receptor PTCH to promote Hh signaling (Okada et al, 2006; Yao et al, 2006; Tenzen et al, 2006, McLellan et al, 2008; Izzi et al, 2011; reviewed in Sanchez-Arrones et al, 2012). Despite the evolutionary conservation, the mode of ligand binding by CDON/Ihog and BOC/Boi is distinct in vertebrates and invertebrates. High affinity ligand-binding by CDON and BOC requires Ca2+, while invertebrate ligand-binding is heparin-dependent (Okada et al, 2006; Tenzen et al, 2006; McLellan et al, 2008; Yao et al, 2006; Kavran et al, 2010). GAS1 is a vertebrate-specific GPI-anchored protein that similarly binds both to Hh ligand and to the PTCH receptor to promote Hh signaling (Martinelli and Fan, 2007; Izzi et al, 2011; reviewed in Kang et al, 2007). CDON, BOC and GAS1 have partially overlapping but not totally redundant roles, and knock-out of all three is required to abrogate Hh signaling in mice (Allen et al, 2011; Izzi et al, 2011; reviewed in Briscoe and Therond, 2013)."
BMGC_PW1357,BMG_PW3958,,,"Hedgehog is a secreted morphogen that has evolutionarily conserved roles in body organization by regulating the activity of the Ci/Gli transcription factor family. In Drosophila in the absence of Hh signaling, full-length Ci is partially degraded by the proteasome to generate a truncated repressor form that translocates to the nucleus to represses Hh-responsive genes. Binding of Hh ligand to the Patched (PTC) receptor allows the 7-pass transmembrane protein Smoothened (SMO) to be activated in an unknown manner, disrupting the partial proteolysis of Ci and allowing the full length activator form to accumulate (reviewed in Ingham et al, 2011; Briscoe and Therond, 2013). While many of the core components of Hh signaling are conserved from flies to humans, the pathways do show points of significant divergence. Notably, the human genome encodes three Ci homologues, GLI1, 2 and 3 that each play slightly different roles in regulating Hh responsive genes. GLI3 is the primary repressor of Hh signaling in vertebrates, and is converted to the truncated GLI3R repressor form in the absence of Hh. GLI2 is a potent activator of transcription in the presence of Hh but contributes only minimally to the repression function. While a minor fraction of GLI2 protein is processed into the repressor form in the absence of Hh, the majority is either fully degraded by the proteasome or sequestered in the full-length form in the cytosol by protein-protein interactions. GLI1 lacks the repression domain and appears to be an obligate transcriptional activator (reviewed in Briscoe and Therond, 2013). Vertebrate but not fly Hh signaling also depends on the movement of pathway components through the primary cilium. The primary cilium is a non-motile microtubule based structure whose construction and maintenance depends on intraflagellar transport (IFT). Anterograde IFT moves molecules from the ciliary base along the axoneme to the ciliary tip in a manner that requires the microtubule-plus-end directed kinesin KIF3 motor complex and the IFT-B protein complex, while retrograde IFT back to the ciliary base depends on the minus-end directed dynein motor and the IFT-A complex. Genetic screens have identified a number of cilia-related proteins that are required both to maintain Hh in the 'off' state and to transduce the signal when the pathway is activated (reviewed in Hui and Angers, 2011; Goetz and Anderson, 2010)."
BMGC_PW1358,BMG_PW3963,,,"Protein stability and transcriptional activity of TP53 (p53) tumor suppressor are regulated by post-translational modifications that include ubiquitination, phosphorylation, acetylation, methylation, sumoylation and prolyl-isomerization (Kruse and Gu 2009, Meek and Anderson 2009, Santiago et al. 2013, Mantovani et al. 2015). In addition to post-translational modifications, the activity of TP53 is also regulated by binding of transcription co-factors. In unstressed cells, TP53 protein levels are low due to MDM2-mediated ubiquitination of TP53, which triggers proteasome-mediated degradation. In response to stress, TP53 undergoes stabilizing phosphorylation, mainly at serine residues S15 and S20. Several different kinases can phosphorylate TP53 at these sites, but the main S15 kinases are considered to be ATM and ATR, while the main S20 kinases are considered to be CHEK2 and CHEK1. Additional phosphorylation of TP53 at serine residue S46 promotes transcription of pro-apoptotic, rather than cell cycle arrest genes. Acetylation mainly has a positive impact on transcriptional activity of TP53, while methylation can both positively and negatively regulate TP53. Some posttranslational modifications regulate interaction of TP53 with transcriptional co-factors, some of which are themselves transcriptional targets of TP53. For review of the complex network of TP53 regulation, please refer to Kruse and Gu 2009, and Meek and Anderson 2009."
BMGC_PW1359,BMG_PW3964,,,"The tumor suppressor TP53 (p53) exerts its tumor suppressive role in part by regulating transcription of a number of genes involved in cell death, mainly apoptotic cell death. The majority of apoptotic genes that are transcriptional targets of TP53 promote apoptosis, but there are also several TP53 target genes that inhibit apoptosis, providing cells with an opportunity to attempt to repair the damage and/or recover from stress. Pro-apoptotic transcriptional targets of TP53 involve TRAIL death receptors TNFRSF10A (DR4), TNFRSF10B (DR5), TNFRSF10C (DcR1) and TNFRSF10D (DcR2), as well as the FASL/CD95L death receptor FAS (CD95). TRAIL receptors and FAS induce pro-apoptotic signaling in response to external stimuli via extrinsic apoptosis pathway (Wu et al. 1997, Takimoto et al. 2000, Guan et al. 2001, Liu et al. 2004, Ruiz de Almodovar et al. 2004, Liu et al. 2005, Schilling et al. 2009, Wilson et al. 2013). IGFBP3 is a transcriptional target of TP53 that may serve as a ligand for a novel death receptor TMEM219 (Buckbinder et al. 1995, Ingermann et al. 2010). TP53 regulates expression of a number of genes involved in the intrinsic apoptosis pathway, triggered by the cellular stress. Some of TP53 targets, such as BAX, BID, PMAIP1 (NOXA), BBC3 (PUMA) and probably BNIP3L, AIFM2, STEAP3, TRIAP1 and TP53AIP1, regulate the permeability of the mitochondrial membrane and/or cytochrome C release (Miyashita and Reed 1995, Oda et al. 2000, Samuels-Lev et al. 2001, Nakano and Vousden 2001, Sax et al. 2002, Passer et al. 2003, Bergamaschi et al. 2004, Li et al. 2004, Fei et al. 2004, Wu et al. 2004, Park and Nakamura 2005, Patel et al. 2008, Wang et al. 2012, Wilson et al. 2013). Other pro-apoptotic genes, either involved in the intrinsic apoptosis pathway, extrinsic apoptosis pathway or pyroptosis (inflammation-related cell death), which are transcriptionally regulated by TP53 are cytosolic caspase activators, such as APAF1, PIDD1, and NLRC4, and caspases themselves, such as CASP1, CASP6 and CASP10 (Lin et al. 2000, Robles et al. 2001, Gupta et al. 2001, MacLachlan and El-Deiry 2002, Rikhof et al. 2003, Sadasivam et al. 2005, Brough and Rothwell 2007). It is uncertain how exactly some of the pro-apoptotic TP53 targets, such as TP53I3 (PIG3), RABGGTA, BCL2L14, BCL6, NDRG1 and PERP contribute to apoptosis (Attardi et al. 2000, Guo et al. 2001, Samuels-Lev et al. 2001, Contente et al. 2002, Ihrie et al. 2003, Bergamaschi et al. 2004, Stein et al. 2004, Phan and Dalla-Favera 2004, Jen and Cheung 2005, Margalit et al. 2006, Zhang et al. 2007, Saito et al. 2009, Davies et al. 2009, Giam et al. 2012). TP53 is stabilized in response to cellular stress by phosphorylation on at least serine residues S15 and S20. Since TP53 stabilization precedes the activation of cell death genes, the TP53 tetramer phosphorylated at S15 and S20 is shown as a regulator of pro-apoptotic/pro-cell death genes. Some pro-apoptotic TP53 target genes, such as TP53AIP1, require additional phosphorylation of TP53 at serine residue S46 (Oda et al. 2000, Taira et al. 2007). Phosphorylation of TP53 at S46 is regulated by another TP53 pro-apoptotic target, TP53INP1 (Okamura et al. 2001, Tomasini et al. 2003). Additional post-translational modifications of TP53 may be involved in transcriptional regulation of genes presented in this pathway and this information will be included as evidence becomes available. Activation of some pro-apoptotic TP53 targets, such as BAX, FAS, BBC3 (PUMA) and TP53I3 (PIG3) requires the presence of the complex of TP53 and an ASPP protein, either PPP1R13B (ASPP1) or TP53BP2 (ASPP2) (Samuels-Lev et al. 2001, Bergamaschi et al. 2004, Patel et al. 2008, Wilson et al. 2013), indicating how the interaction with specific co-factors modulates the cellular response/outcome. TP53 family members TP63 and or TP73 can also activate some of the pro-apoptotic TP53 targets, such as FAS, BAX, BBC3 (PUMA), TP53I3 (PIG3), CASP1 and PERP (Bergamaschi et al. 2004, Jain et al. 2005, Ihrie et al. 2005, Patel et al. 2008, Schilling et al. 2009, Celardo et al. 2013). For a review of the role of TP53 in apoptosis and pro-apoptotic transcriptional targets of TP53, please refer to Riley et al. 2008, Murray-Zmijewski et al. 2008, Bieging et al. 2014, Kruiswijk et al. 2015."
BMGC_PW1360,BMG_PW3966,,,"Activation of the transmembrane protein SMO in response to Hh stimulation is a major control point in the Hh signaling pathway (reviewed in Ayers and Therond, 2010; Jiang and Hui, 2008). In the absence of ligand, SMO is inhibited in an unknown manner by the Hh receptor PTCH. PTCH regulates SMO in a non-stoichiometric manner and there is little evidence that endogenous PTCH and SMO interact directly (Taipale et al, 2002; reviewed in Huangfu and Anderson, 2006). PTCH may regulate SMO activity by controlling the flux of sterol-related SMO agonists and/or antagonists, although this has not been fully substantiated (Khaliullina et al, 2009; reviewed in Rohatgi and Scott, 2007; Briscoe and Therond, 2013). PTCH-mediated inhibition of SMO is relieved upon ligand stimulation of PTCH, but the mechanisms for this relief are again unknown. SMO and PTCH appear to have opposing localizations in both the 'off' and 'on' state, with PTCH exiting and SMO entering the cilium upon Hh pathway activation (Denef et al, 2000; Rohatgi et al, 2007; reviewed in Goetz and Anderson, 2010; Hui and Angers, 2011). Activation of SMO involves a conserved phosphorylation-mediated conformational change in the C-terminal tails that destabilizes an intramolecular interaction and promotes the interaction between adjacent tails in the SMO dimer. In Drosophila, this phosphorylation is mediated by PKA and CK1, while in vertebrates it appears to involve ADRBK1/GRK2 and CSNK1A1. Sequential phosphorylations along multiple serine and threonine motifs in the SMO C-terminal tail appear to allow a graded response to Hh ligand concentration in both flies and vertebrates (Zhao et al, 2007; Chen et al, 2010; Chen et al, 2011). In flies, Smo C-terminal tail phosphorylation promotes an association with the Hedgehog signaling complex (HSC) through interaction with the scaffolding kinesin-2 like protein Cos2, activating the Fu kinase and ultimately releasing uncleaved Ci from the complex (Zhang et al, 2005; Ogden et al, 2003; Lum et al, 2003; reviewed in Mukhopadhyay and Rohatgi, 2014). In vertebrates, SMO C-terminal tail phosphorylation and conformational change is linked to its KIF7-dependent ciliary accumulation (Chen et al, 2011; Zhao et al, 2007; Chen et al, 2010). In the cilium, SMO is restricted to a transition-zone proximal region known as the EvC zone (Yang et al, 2012; Blair et al, 2011; Pusapati et al, 2014; reviewed in Eggenschwiler 2012). Both SMO phosphorylation and its ciliary localization are required to promote the Hh-dependent dissociation of the GLI:SUFU complex, ultimately allowing full-length GLI transcription factors to translocate to the nucleus to activate Hh-responsive genes (reviewed in Briscoe and Therond, 2013)."
BMGC_PW1361,BMG_PW3968,,,"In glioblastoma, the most prevalent EGFR mutation, present in ~25% of tumors, is the deletion of the ligand binding domain of EGFR, accompanied with amplification of the mutated allele, which results in over-expression of the mutant protein known as EGFRvIII. EGFRvIII mutant is not able to bind a ligand, but dimerizes and autophosphorylates spontaneously and is therefore constitutively active (Fernandes et al. 2001). Point mutations in the extracellular domain of EGFR are also frequently found in glioblastoma, but ligand binding ability and responsiveness are preserved (Lee et al. 2006). Similar to EGFR kinase domain mutants, EGFRvIII mutant needs to maintain association with the chaperone heat shock protein 90 (HSP90) for proper functioning (Shimamura et al. 2005, Lavictoire et al. 2003). CDC37 is a co-chaperone of HSP90 that acts as a scaffold and regulator of interaction between HSP90 and its protein kinase clients. CDC37 is frequently over-expressed in cancers involving mutant kinases and acts as an oncogene (Roe et al. 2004, reviewed by Gray Jr. et al. 2008). Expression of EGFRvIII mutant results in aberrant activation of downstream signaling cascades, namely RAS/RAF/MAP kinase signaling and PI3K/AKT signaling, and possibly signaling by PLCG1, which leads to increased cell proliferation and survival, providing selective advantage to cancer cells that harbor EGFRvIII (Huang et al. 2007). EGFRvIII mutant does not autophosorylate on the tyrosine residue Y1069 (i.e. Y1045 in the mature protein), a docking site for CBL, and is therefore unable to recruit CBL ubiquitin ligase, which enables it to escape degradation (Han et al. 2006)"
BMGC_PW1362,BMG_PW3969,,,"EGFRvIII (EGFR V30_R297delinsG) is the most prevalent EGFR variant in glioblastoma, but it is also found in other cancer types. In-frame deletion of the ligand binding domain in EGFRvIII is frequently accompanied with genomic amplification, resulting in over-expression of EGFRvIII. EGFRvIII dimerizes and autophosphorylates spontaneously and is therefore constitutively active (Fernandes et al. 2001)"
BMGC_PW1363,BMG_PW3970,,,"Ligand-responsive EGFR cancer variants harbor mutations in the kinase domain or point mutations in the extracellular domain. These altered EGFR proteins are able to signal in the absence of ligands, but their ligand binding ability is preserved and downstream signaling is potentiated when ligand is available (Greulich et al. 2005, Lee et al. 2006)."
BMGC_PW1364,BMG_PW3971,,,"Signaling by EGFR is frequently activated in cancer through genomic amplification of the EGFR locus, resulting in over-expression of the wild-type protein (Wong et al. 1987)."
BMGC_PW1365,BMG_PW3972,,,"Recombinant monoclonal antibody Cetuximab acts as an antagonist of EGFR ligand binding, and is approved for the treatment of tumors that over-express wild-type EGFR receptor (Cunningham et al. 2004, Li et al. 2005, Burtness et al. 2005). Effective concentrations of covalent tyrosine kinase inhibitors (TKIs) inhibit wild-type EGFR, causing severe side effects (Zhou et al. 2009). Hence, covalent TKIs have not shown much promise in clinical trials (Reviewed by Pao and Chmielecki in 2010)."
BMGC_PW1366,BMG_PW3973,,,"NEIL1 and NEIL2 have a dual DNA glycosylase and beta/delta lyase activity. The AP (apurinic/apyrimidinic) site-directed lyase activity of NEIL1 and NEIL2 is their major physiological role, as they can act on AP sites generated spontaneously or by other DNA glycosylases. NEIL1 or NEIL2 cleave the damaged DNA strand 5' to the AP site, producing a 3' phosphate terminus (3'Pi) and a 5' deoxyribose phosphate terminus (5'dRP). DNA polymerase beta (POLB) excises 5'dRP residue but is unable to add the replacement nucleotide to DNA with the 3'Pi end. PNKP, a DNA 3' phosphatase, removes 3'Pi and enables POLB to incorporate the replacement nucleotide, which is followed by ligation of repaired DNA strand by XRCC1:LIG3 complex (Whitehouse et al. 2001, Wiederhold et al. 2004, Das et al. 2006)."
BMGC_PW1367,BMG_PW3974,,,"Long-patch base excision repair (BER) can proceed through PCNA-dependent DNA strand displacement synthesis by replicative DNA polymerases - DNA polymerase delta complex (POLD) or DNA polymerase epsilon (POLE) complex. The PCNA-dependent branch of long-patch BER may occur in cells in the S phase of the cell cycle, when the replication complexes that contain PCNA, POLD or POLE, RPA and RFC are available. POLB incorporates the first nucleotide at the 3'-end of APEX1-generated single strand break (SSB), thus displacing the damaged AP (abasic) dideoxyribose phosphate residue at the 5'-end of SSB (5'ddRP). PCNA is recruited to BER sites by APEX1 and flap endonuclease FEN1, and loaded onto damaged DNA by RFC. POLD and POLE in complex with PCNA continue the displacement DNA strand synthesis. FEN1 cleaves the displaced DNA strand with the AP residue (5'ddRP), and DNA ligase I (LIG1) ligates the multiple nucleotide patch at the 3' end of the SSB with the FEN1-processed 5'-end of the SSB (Klungland and Lindahl 1997, Stucki et al. 1998, Dianov et al. 1999, Matsumoto et al. 1999, Podlutsky et al. 2001, Dianova et al. 2001, Ranalli et al. 2002)."
BMGC_PW1368,BMG_PW3975,,,"The transit of proteins and other cargo through the cell requires a cellular transport process in which transported substances are moved in membrane-bounded vesicles. Transported substances are enclosed in the vesicle lumen or located in the vesicle membrane. The transport process begins with the formation of the vesicle itself, often triggered by the interaction of the cargo with the vesicle formation machinery. Vesicular transport pathways can include vesicle formation, coating, budding, uncoating and target membrane fusion depending upon the function of the pathway described. Vesicle-mediated transport occurs from within cell via ER and Golgi transport, as well as functioning in the endocytosis of material taken into the cell via scavenger receptors."
BMGC_PW1369,BMG_PW3976,,,"Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR) and other receptors with tyrosine kinase activity. It is known that the src homology region 2 (SH2 domain) of PLC-gamma and of other signaling molecules (such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85) direct their binding toward autophosphorylated tyrosine residues of the FGFR. Recruitment of PLC-gamma results in its phosphorylation and activation by the receptor. Activated PLC-gamma hydrolyzes phosphatidyl inositol[4,5] P2 to form the second messengers diacylglycerol (DAG) and Ins [1,4,5]P3, which stimulate calcium release and activation of calcium/calmodulin dependent kinases."
BMGC_PW1370,BMG_PW3977,,,"Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR) and other receptors with tyrosine kinase activity. It is known that the src homology region 2 (SH2 domain) of PLC-gamma and of other signaling molecules (such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85) direct their binding toward autophosphorylated tyrosine residues of the FGFR. Recruitment of PLC-gamma results in its phosphorylation and activation by the receptor. Activated PLC-gamma hydrolyzes phosphatidyl inositol[4,5] P2 to form the second messengers diacylglycerol (DAG) and Ins [1,4,5]P3, which stimulate calcium release and activation of calcium/calmodulin dependent kinases."
BMGC_PW1371,BMG_PW3978,,,"Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR) and other receptors with tyrosine kinase activity. It is known that the src homology region 2 (SH2 domain) of PLC-gamma and of other signaling molecules (such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85) direct their binding toward autophosphorylated tyrosine residues of the FGFR. Recruitment of PLC-gamma results in its phosphorylation and activation by the receptor. Activated PLC-gamma hydrolyzes phosphatidyl inositol[4,5] P2 to form the second messengers diacylglycerol (DAG) and Ins [1,4,5]P3, which stimulate calcium release and activation of calcium/calmodulin dependent kinases."
BMGC_PW1372,BMG_PW3979,,,"Phospholipase C-gamma (PLC-gamma) is a substrate of the fibroblast growth factor receptor (FGFR) and other receptors with tyrosine kinase activity. It is known that the src homology region 2 (SH2 domain) of PLC-gamma and of other signaling molecules (such as GTPase-activating protein and phosphatidylinositol 3-kinase-associated p85) direct their binding toward autophosphorylated tyrosine residues of the FGFR. Recruitment of PLC-gamma results in its phosphorylation and activation by the receptor. Activated PLC-gamma hydrolyzes phosphatidyl inositol[4,5] P2 to form the second messengers diacylglycerol (DAG) and Ins [1,4,5]P3, which stimulate calcium release and activation of calcium/calmodulin dependent kinases."
BMGC_PW1373,BMG_PW3980,,,"Signaling via FGFRs is mediated via direct recruitment of signaling proteins that bind to tyrosine auto-phosphorylation sites on the activated receptor and via closely linked docking proteins that become tyrosine phosphorylated in response to FGF-stimulation and form a complex with additional complement of signaling proteins. The activation loop in the catalytic domain of FGFR maintains the PTK domain in an inactive or low activity state. The activation-loop of FGFR1, for instance, contains two tyrosine residues that must be autophosphorylated for maintaining the catalytic domain in an active state. In the autoinhibited configuration, a kinase invariant proline residue at the C-terminal end of the activation loop interferes with substrate binding while allowing access to ATP in the nucleotide binding site. In addition to the catalytic PTK core, the cytoplasmic domain of FGFR contains several regulatory sequences. The juxtamembrane domain of FGFRs is considerably longer than that of other receptor tyrosine kinases. This region contains a highly conserved sequence that serves as a binding site for the phosphotyrosine binding (PTB) domain of FRS2. A variety of signaling proteins are phosphorylated in response to FGF stimulation, including Shc, phospholipase-C gamma and FRS2 leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape."
BMGC_PW1374,BMG_PW3981,,,"The exact role of SHC1 in FGFR signaling remains unclear. Numerous studies have shown that the p46 and p52 isoforms of SHC1 are phosphorylated in response to FGF stimulation, but direct interaction with the receptor has not been demonstrated. Co-precipitation of p46 and p52 with the FGFR2 IIIc receptor has been reported, but this interaction is thought to be indirect, possibly mediated by SRC. Consistent with this, co-precipitation of SHC1 and FGFR1 IIIc is seen in mammalian cells expressing v-SRC. The p66 isoform of SHC1 has also been co-precipitated with FGFR3, but this occurs independently of receptor stimulation, and the p66 isoform not been shown to undergo FGF-dependent phosphorylation. SHC1 has been shown to associate with GRB2 and SOS1 in response to FGF stimulation, suggesting that the recruitment of SHC1 may contribute to activation of the MAPK cascade downstream of FGFR."
BMGC_PW1375,BMG_PW3982,,,"The ability of growth factors to protect from apoptosis is primarily due to the activation of the AKT survival pathway. P-I-3-kinase dependent activation of PDK leads to the activation of AKT which in turn affects the activity or expression of pro-apoptotic factors, which contribute to protection from apoptosis. AKT activation also blocks the activity of GSK-3b which could lead to additional antiapoptotic signals."
BMGC_PW1376,BMG_PW3983,,,"The FRS family of scaffolding adaptor proteins has two members, FRS2 (also known as FRS2 alpha) and FRS3 (also known as FRS2beta or SNT-2). Activation of FGFR tyrosine kinase allows FRS proteins to become phosphorylated on tyrosine residues and then bind to the adaptor GRB2 and the tyrosine phosphatase PPTN11/SHP2. Subsequently, PPTN11 activates the RAS-MAP kinase pathway and GRB2 activates the RAS-MAP kinase , PI-3-kinase and ubiquitinations/degradation pathways by binding to SOS, GAB1 and CBL, respectively, via the SH3 domains of GRB2. FRS2 acts as a central mediator in FGF signaling mainly because it induces sustained levels of activation of ERK with ubiquitous expression."
BMGC_PW1377,BMG_PW3984,,,"The ability of growth factors to protect from apoptosis is primarily due to the activation of the AKT survival pathway. P-I-3-kinase dependent activation of PDK leads to the activation of AKT which in turn affects the activity or expression of pro-apoptotic factors, which contribute to protection from apoptosis. AKT activation also blocks the activity of GSK-3b which could lead to additional antiapoptotic signals."
BMGC_PW1378,BMG_PW3985,,,"Signaling via FGFRs is mediated via direct recruitment of signaling proteins that bind to tyrosine auto-phosphorylation sites on the activated receptor and via closely linked docking proteins that become tyrosine phosphorylated in response to FGF-stimulation and form a complex with additional complement of signaling proteins. The activation loop in the catalytic domain of FGFR maintains the PTK domain in an inactive or low activity state. The activation-loop of FGFR1, for instance, contains two tyrosine residues that must be autophosphorylated for maintaining the catalytic domain in an active state. In the autoinhibited configuration, a kinase invariant proline residue at the C-terminal end of the activation loop interferes with substrate binding while allowing access to ATP in the nucleotide binding site. In addition to the catalytic PTK core, the cytoplasmic domain of FGFR contains several regulatory sequences. The juxtamembrane domain of FGFRs is considerably longer than that of other receptor tyrosine kinases. This region contains a highly conserved sequence that serves as a binding site for the phosphotyrosine binding (PTB) domain of FRS2. A variety of signaling proteins are phosphorylated in response to FGF stimulation, including Shc, phospholipase-C gamma and FRS2 leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape."
BMGC_PW1379,BMG_PW3986,,,"The exact role of SHC1 in FGFR signaling remains unclear. Numerous studies have shown that the p46 and p52 isoforms of SHC1 are phosphorylated in response to FGF stimulation, but direct interaction with the receptor has not been demonstrated. Co-precipitation of p46 and p52 with the FGFR2 IIIc receptor has been reported, but this interaction is thought to be indirect, possibly mediated by SRC. Consistent with this, co-precipitation of SHC1 and FGFR1 IIIc is seen in mammalian cells expressing v-SRC. The p66 isoform of SHC1 has also been co-precipitated with FGFR3, but this occurs independently of receptor stimulation, and the p66 isoform not been shown to undergo FGF-dependent phosphorylation. SHC1 has been shown to associate with GRB2 and SOS1 in response to FGF stimulation, suggesting that the recruitment of SHC1 may contribute to activation of the MAPK cascade downstream of FGFR."
BMGC_PW1380,BMG_PW3987,,,"The FRS family of scaffolding adaptor proteins has two members, FRS2 (also known as FRS2 alpha) and FRS3 (also known as FRS2beta or SNT-2). Activation of FGFR tyrosine kinase allows FRS proteins to become phosphorylated on tyrosine residues and then bind to the adaptor GRB2 and the tyrosine phosphatase PPTN11/SHP2. Subsequently, PPTN11 activates the RAS-MAP kinase pathway and GRB2 activates the RAS-MAP kinase , PI-3-kinase and ubiquitinations/degradation pathways by binding to SOS, GAB1 and CBL, respectively, via the SH3 domains of GRB2. FRS2 acts as a central mediator in FGF signaling mainly because it induces sustained levels of activation of ERK with ubiquitous expression."
BMGC_PW1381,BMG_PW3988,,,"The exact role of SHC1 in FGFR signaling remains unclear. Numerous studies have shown that the p46 and p52 isoforms of SHC1 are phosphorylated in response to FGF stimulation, but direct interaction with the receptor has not been demonstrated. Co-precipitation of p46 and p52 with the FGFR2 IIIc receptor has been reported, but this interaction is thought to be indirect, possibly mediated by SRC. Consistent with this, co-precipitation of SHC1 and FGFR1 IIIc is seen in mammalian cells expressing v-SRC. The p66 isoform of SHC1 has also been co-precipitated with FGFR3, but this occurs independently of receptor stimulation, and the p66 isoform not been shown to undergo FGF-dependent phosphorylation. SHC1 has been shown to associate with GRB2 and SOS1 in response to FGF stimulation, suggesting that the recruitment of SHC1 may contribute to activation of the MAPK cascade downstream of FGFR."
BMGC_PW1382,BMG_PW3989,,,"The FRS family of scaffolding adaptor proteins has two members, FRS2 (also known as FRS2 alpha) and FRS3 (also known as FRS2beta or SNT-2). Activation of FGFR tyrosine kinase allows FRS proteins to become phosphorylated on tyrosine residues and then bind to the adaptor GRB2 and the tyrosine phosphatase PPTN11/SHP2. Subsequently, PPTN11 activates the RAS-MAP kinase pathway and GRB2 activates the RAS-MAP kinase , PI-3-kinase and ubiquitinations/degradation pathways by binding to SOS, GAB1 and CBL, respectively, via the SH3 domains of GRB2. FRS2 acts as a central mediator in FGF signaling mainly because it induces sustained levels of activation of ERK with ubiquitous expression."
BMGC_PW1383,BMG_PW3990,,,"Signaling via FGFRs is mediated via direct recruitment of signaling proteins that bind to tyrosine auto-phosphorylation sites on the activated receptor and via closely linked docking proteins that become tyrosine phosphorylated in response to FGF-stimulation and form a complex with additional complement of signaling proteins. The activation loop in the catalytic domain of FGFR maintains the PTK domain in an inactive or low activity state. The activation-loop of FGFR1, for instance, contains two tyrosine residues that must be autophosphorylated for maintaining the catalytic domain in an active state. In the autoinhibited configuration, a kinase invariant proline residue at the C-terminal end of the activation loop interferes with substrate binding while allowing access to ATP in the nucleotide binding site. In addition to the catalytic PTK core, the cytoplasmic domain of FGFR contains several regulatory sequences. The juxtamembrane domain of FGFRs is considerably longer than that of other receptor tyrosine kinases. This region contains a highly conserved sequence that serves as a binding site for the phosphotyrosine binding (PTB) domain of FRS2. A variety of signaling proteins are phosphorylated in response to FGF stimulation, including Shc, phospholipase-C gamma and FRS2 leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape."
BMGC_PW1384,BMG_PW3991,,,"The ability of growth factors to protect from apoptosis is primarily due to the activation of the AKT survival pathway. P-I-3-kinase dependent activation of PDK leads to the activation of AKT which in turn affects the activity or expression of pro-apoptotic factors, which contribute to protection from apoptosis. AKT activation also blocks the activity of GSK-3b which could lead to additional antiapoptotic signals."
BMGC_PW1385,BMG_PW3992,,,"The FRS family of scaffolding adaptor proteins has two members, FRS2 (also known as FRS2 alpha) and FRS3 (also known as FRS2beta or SNT-2). Activation of FGFR tyrosine kinase allows FRS proteins to become phosphorylated on tyrosine residues and then bind to the adaptor GRB2 and the tyrosine phosphatase PPTN11/SHP2. Subsequently, PPTN11 activates the RAS-MAP kinase pathway and GRB2 activates the RAS-MAP kinase , PI-3-kinase and ubiquitinations/degradation pathways by binding to SOS, GAB1 and CBL, respectively, via the SH3 domains of GRB2. FRS2 acts as a central mediator in FGF signaling mainly because it induces sustained levels of activation of ERK with ubiquitous expression."
BMGC_PW1386,BMG_PW3993,,,"Signaling via FGFRs is mediated via direct recruitment of signaling proteins that bind to tyrosine auto-phosphorylation sites on the activated receptor and via closely linked docking proteins that become tyrosine phosphorylated in response to FGF-stimulation and form a complex with additional complement of signaling proteins. The activation loop in the catalytic domain of FGFR maintains the PTK domain in an inactive or low activity state. The activation-loop of FGFR1, for instance, contains two tyrosine residues that must be autophosphorylated for maintaining the catalytic domain in an active state. In the autoinhibited configuration, a kinase invariant proline residue at the C-terminal end of the activation loop interferes with substrate binding while allowing access to ATP in the nucleotide binding site. In addition to the catalytic PTK core, the cytoplasmic domain of FGFR contains several regulatory sequences. The juxtamembrane domain of FGFRs is considerably longer than that of other receptor tyrosine kinases. This region contains a highly conserved sequence that serves as a binding site for the phosphotyrosine binding (PTB) domain of FRS2. A variety of signaling proteins are phosphorylated in response to FGF stimulation, including Shc, phospholipase-C gamma and FRS2 leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape."
BMGC_PW1387,BMG_PW3994,,,"The exact role of SHC1 in FGFR signaling remains unclear. Numerous studies have shown that the p46 and p52 isoforms of SHC1 are phosphorylated in response to FGF stimulation, but direct interaction with the receptor has not been demonstrated. Co-precipitation of p46 and p52 with the FGFR2 IIIc receptor has been reported, but this interaction is thought to be indirect, possibly mediated by SRC. Consistent with this, co-precipitation of SHC1 and FGFR1 IIIc is seen in mammalian cells expressing v-SRC. The p66 isoform of SHC1 has also been co-precipitated with FGFR3, but this occurs independently of receptor stimulation, and the p66 isoform not been shown to undergo FGF-dependent phosphorylation. SHC1 has been shown to associate with GRB2 and SOS1 in response to FGF stimulation, suggesting that the recruitment of SHC1 may contribute to activation of the MAPK cascade downstream of FGFR."
BMGC_PW1388,BMG_PW3995,,,"The ability of growth factors to protect from apoptosis is primarily due to the activation of the AKT survival pathway. P-I-3-kinase dependent activation of PDK leads to the activation of AKT which in turn affects the activity or expression of pro-apoptotic factors, which contribute to protection from apoptosis. AKT activation also blocks the activity of GSK-3b which could lead to additional antiapoptotic signals."
BMGC_PW1389,BMG_PW3996,,,"Once activated, the FGFR signaling pathway is regulated by numerous negative feedback mechanisms. These include downregulation of receptors through CBL-mediated ubiquitination and endocytosis, ERK-mediated inhibition of FRS2-tyrosine phosphorylation and the attenuation of ERK signaling through the action of dual-specificity phosphatases, IL17RD/SEF, Sprouty and Spred proteins. A number of these inhibitors are themselves transcriptional targets of the activated FGFR pathway."
BMGC_PW1390,BMG_PW3997,,,"Once activated, the FGFR signaling pathway is regulated by numerous negative feedback mechanisms. These include downregulation of receptors through CBL-mediated ubiquitination and endocytosis, ERK-mediated inhibition of FRS2-tyrosine phosphorylation and the attenuation of ERK signaling through the action of dual-specificity phosphatases, IL17RD/SEF, Sprouty and Spred proteins. A number of these inhibitors are themselves transcriptional targets of the activated FGFR pathway."
BMGC_PW1391,BMG_PW3998,,,"Once activated, the FGFR signaling pathway is regulated by numerous negative feedback mechanisms. These include downregulation of receptors through CBL-mediated ubiquitination and endocytosis, ERK-mediated inhibition of FRS2-tyrosine phosphorylation and the attenuation of ERK signaling through the action of dual-specificity phosphatases, IL17RD/SEF, Sprouty and Spred proteins. A number of these inhibitors are themselves transcriptional targets of the activated FGFR pathway."
BMGC_PW1392,BMG_PW3999,,,"Once activated, the FGFR signaling pathway is regulated by numerous negative feedback mechanisms. These include downregulation of receptors through CBL-mediated ubiquitination and endocytosis, ERK-mediated inhibition of FRS2-tyrosine phosphorylation and the attenuation of ERK signaling through the action of dual-specificity phosphatases, IL17RD/SEF, Sprouty and Spred proteins. A number of these inhibitors are themselves transcriptional targets of the activated FGFR pathway."
BMGC_PW1393,BMG_PW4000,,,"The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. These receptors are key regulators of several developmental processes in which cell fate and differentiation to various tissue lineages are determined. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. An alternative, FGF-independent, source of FGFR activation originates from the interaction with cell adhesion molecules, typically in the context of interactions on neural cell membranes and is crucial for neuronal survival and development. Upon ligand binding, receptor dimers are formed and their intrinsic tyrosine kinase is activated causing phosphorylation of multiple tyrosine residues on the receptors. These then serve as docking sites for the recruitment of SH2 (src homology-2) or PTB (phosphotyrosine binding) domains of adaptors, docking proteins or signaling enzymes. Signaling complexes are assembled and recruited to the active receptors resulting in a cascade of phosphorylation events. This leads to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape, depending on the cell type or stage of maturation."
BMGC_PW1394,BMG_PW4001,,,"The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. These receptors are key regulators of several developmental processes in which cell fate and differentiation to various tissue lineages are determined. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. An alternative, FGF-independent, source of FGFR activation originates from the interaction with cell adhesion molecules, typically in the context of interactions on neural cell membranes and is crucial for neuronal survival and development. Upon ligand binding, receptor dimers are formed and their intrinsic tyrosine kinase is activated causing phosphorylation of multiple tyrosine residues on the receptors. These then serve as docking sites for the recruitment of SH2 (src homology-2) or PTB (phosphotyrosine binding) domains of adaptors, docking proteins or signaling enzymes. Signaling complexes are assembled and recruited to the active receptors resulting in a cascade of phosphorylation events. This leads to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape, depending on the cell type or stage of maturation."
BMGC_PW1395,BMG_PW4002,,,"The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. These receptors are key regulators of several developmental processes in which cell fate and differentiation to various tissue lineages are determined. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. An alternative, FGF-independent, source of FGFR activation originates from the interaction with cell adhesion molecules, typically in the context of interactions on neural cell membranes and is crucial for neuronal survival and development. Upon ligand binding, receptor dimers are formed and their intrinsic tyrosine kinase is activated causing phosphorylation of multiple tyrosine residues on the receptors. These then serve as docking sites for the recruitment of SH2 (src homology-2) or PTB (phosphotyrosine binding) domains of adaptors, docking proteins or signaling enzymes. Signaling complexes are assembled and recruited to the active receptors resulting in a cascade of phosphorylation events. This leads to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape, depending on the cell type or stage of maturation."
BMGC_PW1396,BMG_PW4003,,,"The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. These receptors are key regulators of several developmental processes in which cell fate and differentiation to various tissue lineages are determined. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. An alternative, FGF-independent, source of FGFR activation originates from the interaction with cell adhesion molecules, typically in the context of interactions on neural cell membranes and is crucial for neuronal survival and development. Upon ligand binding, receptor dimers are formed and their intrinsic tyrosine kinase is activated causing phosphorylation of multiple tyrosine residues on the receptors. These then serve as docking sites for the recruitment of SH2 (src homology-2) or PTB (phosphotyrosine binding) domains of adaptors, docking proteins or signaling enzymes. Signaling complexes are assembled and recruited to the active receptors resulting in a cascade of phosphorylation events. This leads to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape, depending on the cell type or stage of maturation."
BMGC_PW1397,BMG_PW4004,,,"The FGFR2 gene has been shown to be subject to activating mutations and gene amplification leading to a variety of proliferative and developmental disorders depending on whether these events occur in the germline or arise somatically. Activating FGFR2 mutations in the germline give rise to a range of craniosynostotic conditions including Pfeiffer, Apert, Jackson-Weiss, Crouzon and Beare-Stevensen Cutis Gyrata syndromes. These autosomal dominant skeletal disorders are characterized by premature fusion of several sutures in the skull, and in some cases also involve syndactyly (abnormal bone fusions in the hands and feet) (reviewed in Webster and Donoghue, 1997; Burke, 1998; Cunningham, 2007). Activating FGFR2 mutations arising somatically have been linked to the development of gastric and endometrial cancers (reviewed in Greulich and Pollock, 2011; Wesche, 2011). Many of these mutations are similar or identical to those that contribute to the autosomal disorders described above. Notably, loss-of-function mutations in FGFR2 have also been recently described in melanoma (Gartside, 2009). FGFR2 may also contribute to tumorigenesis through overexpression, as FGFR2 has been identified as a target of gene amplification in gastric and breast cancers (Kunii, 2008; Takeda, 2007)."
BMGC_PW1398,BMG_PW4005,,,"FGFR4 is perhaps the least well studied of the FGF receptors, and unlike the case for the other FGFR genes, mutations in FGFR4 are not known to be associated with any developmental disorders. Recently, however, somatically arising mutations in the FGFR4 coding sequence have begun to be identified in some cancers. 8% of rhabdomyosarcomas have activating mutations in the kinase domain of FGFR4. Two of these mutations - N535K (paralogous to the FGFR2 N550K allele found in endometrial cancers) and V550E - have been shown to support the oncogenic transformation of NIH 3T3 cells (Taylor, 2009). An FGFR4 Y367C mutation has also been identified in breast cancers (Ruhe, 2007; Roidl, 2010); mutations of paralogous residues in FGFR2 and FGFR3 are associated with both skeletal dysplasias and the development of diverse cancers (Pollock, 2007; Ruhe, 2007; Rousseau, 1996; Chesi, 1997, 2001). Finally, a SNP at position 388 of FGFR4 is associated with aggressive disease development. Expression of the G388R allele in breast, colorectal and prostate cancers is correlated with rapid progression times and increased rates of recurrence and metastasis (Bange, 2002; Spinola, 2005; Wang, 2004)."
BMGC_PW1399,BMG_PW4006,,,"The FGFR1 gene has been shown to be subject to activating mutations, chromosomal rearrangements and gene amplification leading to a variety of proliferative and developmental disorders depending on whether these events occur in the germline or arise somatically (reviewed in Webster and Donoghue, 1997; Burke, 1998; Cunningham, 2007; Wesche, 2011; Greulich and Pollock, 2011). Activating mutation P252R in FGFR1 is associated with the development of Pfeiffer syndrome, characterized by craniosynostosis (premature fusion of several sutures in the skull) and broadened thumbs and toes (Muenke, 1994; reviewed in Cunningham, 2007). This residue falls in a highly conserved Pro-Ser dipeptide between the second and third Ig domains of the extracellular region of the receptor. The mutation is thought to increase the number of hydrogen bonds formed with the ligand and to thereby increase ligand-binding affinity (Ibrahimi, 2004a). Unlike other FGF receptors, few activating point mutations in the FGFR1 coding sequence have been identified in cancer. Point mutations in the Ig II-III linker analagous to the P252R Pfeiffer syndrome mutation have been identified in lung cancer and melanoma (Ruhe, 2007; Davies, 2005), and two kinase-domain mutations in FGFR1 have been identified in glioblastoma (Rand, 2005, Network TCGA, 2008). In contrast, FGFR1 is a target of chromosomal rearrangements in a number of cancers. FGFR1 has been shown to be recurrently translocated in the 8p11 myeloproliferative syndrome (EMS), a pre-leukemic condition also known as stem cell leukemia/lymphoma (SCLL) that rapidly progresses to leukemia. This translocation fuses the kinase domain of FGFR1 with the dimerization domain of one of 10 identified fusion partners, resulting in the constitutive dimerization and activation of the kinase (reviewed in Jackson, 2010). Amplification of the FGFR1 gene has been implicated as a oncogenic factor in a range of cancers, including breast, ovarian, bladder, lung, oral squamous carcinomas, and rhabdomyosarcoma (reviewed in Turner and Grose, 2010; Wesche, 2011; Greulich and Pollock, 2011), although there are other candidate genes in the amplified region and the definitive role of FGFR1 has not been fully established. More recently, FGFR1 fusion proteins have been identified in a number of cancers; these are thought to undergo constitutive ligand-independent dimerization and activation based on dimerization motifs found in the fusion partners (reviewed in Parker, 2014)."
BMGC_PW1400,BMG_PW4007,,,"The FGFR3 gene has been shown to be subject to activating mutations and gene amplification leading to a variety of proliferative and developmental disorders depending on whether these events occur in the germline or arise somatically. Activating mutations in FGFR3 are associated with the development of a range of skeletal dysplasias that result in dwarfism (reviewed in Webster and Donoghue, 1997; Burke et al, 1998; Harada et al, 2009). The most common form of human dwarfism is achondroplasia (ACH), which is caused by mutations G380R and G375C in the transmembrane domain of FGFR3 that are thought to promote ligand-independent dimerization (Rousseau et al, 1994; Shiang et al, 1994; Bellus et al, 1995a) Hypochondroplasia (HCH) is a milder form dwarfism that is the result of mutations in the tyrosine kinase domain of FGFR3 (Bellus et al, 1995b). Two neonatal lethal conditions, thanatophoric dysplasia type I and II (TDI and TDII) are also the result of mutations in FGFR3; TDI arises from a range of mutations that either result in the formation of unpaired cysteine residues in the extracellular region that promote aberrant ligand-independent dimerization or by mutations that introduce stop codons (Rousseau et al, 1995; Rousseau et al, 1996, D'Avis et al,1998). A single mutation, K650E in the second tyrosine kinase domain of FGFR3 is responsible for all identified cases of TDII (Tavormina et al, 1995a, b). Other missense mutations at the same K650 residue give rise to Severe Achondroplasia with Developmental Disorders and Acanthosis Nigricans (SADDAN) syndrome (Tavormina et al, 1999; Bellus et al, 1999). The severity of the phenotype arising from many of the activating FGFR3 mutations has recently been shown to correlate with the extent to which the mutations activate the receptor (Naski et al, 1996; Bellus et al, 2000) In addition to mutations that cause dwarfism syndromes, a Pro250Arg mutation in the conserved dipeptide between the IgII and IgIII domains has been identified in an atypical craniosynostosis condition (Bellus et al, 1996; Reardon et al, 1997). This mutation, which is paralogous to mutations seen in FGFR1 and 2 in Pfeiffer and Apert Syndrome, respectively, results in an increase in ligand-binding affinity for the receptor (Ibrahimi et al, 2004b). Of all the FGF receptors, FGFR3 has perhaps the best established link to the development in cancer. 50% of bladder cancers have somatic mutations in the coding sequence of FGFR3; of these, more than half occur in the extracellular region at a single position (S249C) (Cappellen et al, 1999; Naski et al, 1996; di Martino et al, 2009, Sibley et al, 2001). Activating mutations are also seen in the juxta- and trans-membrane domains, as well as in the kinase domain (reviewed in Weshe et al, 2011). As is the case for the other receptors, many of the activating mutations that are seen in FGFR3-related cancers mimic the germline FGFR3 mutations that give rise to autosomal skeletal disorders and include both ligand-dependent and independent mechanisms (reviewed in Webster and Donoghue, 1997; Burke et al, 1998). In addition to activating mutations, the FGFR3 gene is subject to a translocation event in 15% of multiple myelomas (Avet-Loiseau et al, 1998; Chesi et al, 1997). This chromosomal rearrangement puts the FGFR3 gene under the control of the highly active IGH promoter and promotes overexpression and constitutive activation of FGFR3. In a small proportion of multiple myelomas, the translocation event is accompanied by activating mutations in the FGFR3 coding sequence (Chesi et al, 1997). More recently, a number of fusion proteins of FGFR3 have been identified in various cancers (Singh et al, 2012; Williams et al, 2013; Parker et al, 2013; Wu et al, 2013; Wang et al, 2014; Yuan et al, 2014; reviewed in Parker et al, 2014). The most common fusion protein is TACC3, a coiled coil protein involved in mitotic spindle assembly. FGFR3 fusion proteins are constitutively active and appear to contribute to proliferation and tumorigenesis through activation of the ERK and AKT signaling pathways (reviewed in Parker et al, 2014)."
BMGC_PW1401,BMG_PW4009,,,
BMGC_PW1402,BMG_PW4010,,,"DNA polymerase iota (POLI) is a Y family DNA polymerase with an active site that favours Hoogsteen base pairing instead of Watson-Crick base pairing. POLI-mediated Hoogsteen base pairing and rotation of template purines from anti to syn conformation serves as a mechanism to displace adducts on template G or template A that interfere with DNA replication, or to allow base pairing of damaged purines with a disrupted Watson-Crick edge but an intact Hoogsteen edge (Nair et al. 2004, Nair et al. 2006). POLI is recruited to DNA damage sites through its interaction with PCNA and REV1. POLI contains a PIP box and two UBMs (ubiquitin binding motifs) that are responsible for POLI binding to monoubiquitinated PCNA (MonoUb:K164-PCNA) (Bienko et al. 2005, Haracska et al. 2005, Bomar et al. 2010). The interaction between POLI and the C-terminus of REV1 is evolutionarily conserved (Kosarek et al. 2003, Guo et al. 2003, Ohashi et al. 2004). After it incorporates a dNMP opposite to damaged template base, POLI is unable to efficiently elongate the DNA strand further. The elongation step is performed by the polymerase zeta complex (POLZ), composed of REV3L and MAD2L2 subunits (Johnson et al. 2000). The involvement of REV1 and POLZ in POLI-mediated translesion DNA synthesis (TLS) suggests that POLI forms a quaternary complex with REV1 and POLZ, as shown for POLK and proposed for other Y family DNA polymerases (Xie et al. 2012)."
BMGC_PW1403,BMG_PW4011,,,"The initiation and extent of translesion DNA synthesis (TLS) has to be tightly controlled in order to limit TLS-induced mutagenesis, caused by the low fidelity of TLS-participating DNA polymerases. Since monoubiquitination of PCNA at lysine residue K164 is a prerequisite for the assembly of TLS complexes on damaged DNA templates, PCNA deubiquitination is a key step in TLS termination that allows DNA polymerase switching from Y family DNA polymerases involved in TLS to replicative DNA polymerases delta and epsilon (Povlsen et al. 2012, Park et al. 2014)."
BMGC_PW1404,BMG_PW4017,,,"The intrinsic GTPase activity of RAS proteins is stimulated by the GAP proteins, of which there are at least 10 in the human genome (reviewed in King et al, 2013)."
BMGC_PW1405,BMG_PW4019,,,"FGFRL1 is a fifth member of the FGFR family of receptors. The extracellular region has 40% sequence similarity with FGFR1-4, but FGFRL1 lacks the internal kinase domain of the other FGF receptors and how it acts in FGFR signaling is unclear. Some models suggest FGFRL1 restricts canonical FGFR signaling by sequestering ligand away from kinase-active receptors, while other models suggest that FGFRL1 may promote canonical signaling by nucleating signaling complexes or enhancing ERK1/2 activation (reviewed in Trueb, 2011; Trueb et al, 2013)."
BMGC_PW1406,BMG_PW4025,,,"Though metals such as zinc, copper, and iron are required as cofactors for cellular enzymes they can also catalyze damaging metal substitution or unspecific redox reactions if they are not sequestered. The transcription factor MTF1 directs the major cellular response to zinc, cadmium, and copper. MTF1 activates gene expression to up-regulate genes encoding proteins, such as metallothioneins and glutamate-cysteine ligase (GCLC), involved in sequestering metals. MTF1 represses gene expression to down-regulate genes encoding transporters that import the metals into the cell (reviewed in Laity and Andrews 2007, Jackson et al. 2008, Günther et al. 2012, Dong et al. 2015). During activation MTF1 in the cytosol binds zinc ions and is translocated into the nucleus, where it binds metal response elements in the promoters of target genes. Activation of MTF1 by cadmium and copper appears to be indirect as these metals displace zinc from metallothioneins and the displaced zinc then binds MTF1. Metallothioneins bind metals and participate in detoxifying heavy metals, storing and transporting zinc, and redox biochemistry."
BMGC_PW1407,BMG_PW4026,,,"Antifungal immunity through the induction of T-helper 17 cells (TH17) responses requires the production of mature, active interleukin-1beta (IL1B). CLEC7A (dectin-1) through the SYK route induces activation of NF-kB and transcription of the gene encoding pro-IL1B via the CARD9-BCL10-MALT1 complex as well as the formation and activation of a MALT1-caspase-8-ASC complex that mediated the processing of pro-IL1B. The inactive precursor pro-IL1B has to be processed into mature bioactive form of IL1B and is usually mediated by inflammatory cysteine protease caspase-1. Gringhuis et al. showed that CLEC7A mediated processing of IL1B occurs through two distinct mechanisms: CLEC7A triggering induced a primary noncanonical caspase-8 inflammasome for pro-IL1B processing that was independent of caspase-1 activity, whereas some fungi triggered a second additional mechanism that required activation of the NLRP3/caspase 1 inflammasome. Unlike the canonical caspase-1 inflammasome, CLEC7A mediated noncanonical caspase-8-dependent inflammasome is independent of pathogen internalization. CLEC7A/inflammasome pathway enables the host immune system to mount a protective TH17 response against fungi and bacterial infection (Gringhuis et al. 2012, Cheng et al. 2011)."
BMGC_PW1408,BMG_PW4031,,,"Metallothioneins are highly conserved, cysteine-rich proteins that bind metals via thiolate bonds (recent general reviews in Capdevila et al. 2012, Blindauer et al. 2014, reviews of mammalian metallothioneins in Miles et al. 2000, Maret 2011, Vasak and Meloni 2011, Thirumoorthy et al. 2001, Babula et al. 2012). Mammals contain 4 general metallothionein isoforms (MT1,2,3,4). The MT1 isoform has radiated in primates to 8 or 9 functional proteins (depending on classification of MT1L). Each mammalian metallothionein binds a total of 7 divalent metal ions in two clusters, the alpha and beta clusters. Though the functions of metallothioneins have not been fully elucidated, they appear to participate in detoxifying heavy metals (reviewed in Sharma et al. 2013), storing and transporting zinc, and redox biochemistry. Metallothioneins interact with many other cellular proteins, with most interactions involving proteins of the central nervous system (reviewed in Atrian and Capdevila 2013)."
BMGC_PW1409,BMG_PW4032,,,"The conversion of D-glucuronate to D-xylulose-5-phosphate, an intermediate in the pentose phosphate pathway, proceeds via L-gulonate, 3-dehydro-L-gulonate, L-xylulose, xylitol, and D-xylulose (Wamelink et al. 2008). D-glucuronate can be generated via the degradation of glucuronidated proteins. This pathway would have the effect of returning it to the pentose phosphate pathway or glycolysis."
BMGC_PW1410,BMG_PW4033,,"Cutaneous melanin pigment plays a critical role in camouflage, mimicry, social communication, and protection against harmful effects of solar radiation. Melanogenesis is under complex regulatory control by multiple agents. The most important positive regulator of melanogenesis is the MC1 receptor with its ligands melanocortic peptides. MC1R activates the cyclic AMP (cAMP) response-element binding protein (CREB). Increased expression of MITF and its activation by phosphorylation (P) stimulate the transcription of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), and dopachrome tautomerase (DCT), which produce melanin. Melanin synthesis takes place within specialized intracellular organelles named melanosomes. Melanin-containing melanosomes then move from the perinuclear region to the dendrite tips and are transferred to keratinocytes by a still not well-characterized mechanism.","Melanin biosynthesis takes place in specialized cells called melanocytes, within membrane-bound organelles referred to as melanosomes. Melanosomes are transferred via dendrites to surrounding keratinocytes. Keratinocytes and melanocytes are collectively known as 'the epidermal melanin unit'. Each melanocyte is in contact with approximately 40 keratinocytes in the basal and suprabasal layers (Cichorek et al. 2013). Melanocytes are distributed in the epidermis, hair follicles, the inner ear and the eye (Yamaguchi et al. 2007, Tolleson 2005). Melanocytes in mammals and birds produce two chemically distinct types of melanin, black to brown eumelanin and yellow to reddish-brown pheomelanin (Ito & Wakamatsu 2008, Simon et al. 2009, d'Ischia et al. 2013). These differ in their responses to UV radiation; eumelanin has the ability to convert absorbed light energy into heat energy (Meredith & Riesz 2004) and to detoxify reactive oxygen species (ROS) (Bustamante et al. 1993), while pheomelanin is a phototoxic pro-oxidant (Samokhvalov 2005). Most natural melanin pigments contain eumelanin and pheomelanin (Ito & Wakamatsu 2003) and are termed 'mixed' melanins. Neuromelanins are mixed melanin-like pigments which are mainly found in neurons of the substantia nigra and locus coeruleus (Fedorow et al. 2005). Synthesis of NM may prevent the accumulation of toxic catechol derivatives (Zecca et al. 2003). NM can sequester a variety of potentially damaging molecules such as beta-carbolines, heavy metal ions and 1-methyl-4-phenylpyridinium (MPP+) (D'Amato et al. 1986), a drug which causes Parkinson's Disease-like symptoms. Models suggest that mixed melanogenesis occurs in three stages (Ito et al. 2000). The initial stage of melanin biosynthesis is the production of cysteinyldopas, which continues while sufficient cysteine is available. The second stage is the oxidation of cysteinyldopas to produce pheomelanin, which continues while cysteinyldopa concentration is sufficiently high. The last stage is the production of eumelanin, which begins when cysteinyldopas and cysteine are depleted. The ratio of eumelanin to pheomelanin is determined by tyrosinase activity and the availability of tyrosine and cysteine (Land et al. 2003)."
BMGC_PW1411,BMG_PW4036,,,
BMGC_PW1412,BMG_PW4037,,,"Signaling processes are central to human physiology (e.g., Pires-da Silva & Sommer 2003), and their disruption by either germ-line and somatic mutation can lead to serious disease. Here, the molecular consequences of mutations affecting visual signal transduction and signaling by diverse growth factors are annotated."
BMGC_PW1413,BMG_PW4038,,,"WASP and WAVE proteins belong to the Wiskott-Aldrich Syndrome protein family, with recessive mutations in the founding member WASP being responsible for the X-linked recessive immunodeficieny known as the Wiskott-Aldrich Syndrome. WASP proteins include WASP and WASL (N-WASP). WAVE proteins include WASF1 (WAVE1), WASF2 (WAVE2) and WASF3 (WAVE3). WASPs and WAVEs contain a VCA domain (consisting of WH2 and CA subdomains) at the C-terminus, responsible for binding to G-actin (WH2 subdomain) and the actin-associated ARP2/3 complex (CA subdomain). WASPs contain a WH1 (WASP homology 1) domain at the N-terminus, responsible for binding to WIPs (WASP-interacting proteins). A RHO GTPase binding domain (GBD) is located in the N-terminal half of WASPs and C-terminally located in WAVEs. RHO GTPases activate WASPs by disrupting the autoinhibitory interaction between the GBD and VCA domains, which allows WASPs to bind actin and the ARP2/3 complex and act as nucleation promoting factors in actin polymerization. WAVEs have the WAVE/SCAR homology domain (WHD/SHD) at the N-terminus, which binds ABI, NCKAP1, CYFIP2 and BRK1 to form the WAVE regulatory complex (WRC). Binding of the RAC1:GTP to the GBD of WAVEs most likely induces a conformational change in the WRC that allows activating phosphorylation of WAVEs by ABL1, thus enabling them to function as nucleation promoting factors in actin polymerization through binding G-actin and the ARP2/3 complex (Reviewed by Lane et al. 2014)."
BMGC_PW1414,BMG_PW4039,,,"Formins are a family of proteins with 15 members in mammals, organized into 8 subfamilies. Formins are involved in the regulation of actin cytoskeleton. Many but not all formin family members are activated by RHO GTPases. Formins that serve as effectors of RHO GTPases belong to different formin subfamilies but they all share a structural similarity to Drosophila protein diaphanous and are hence named diaphanous-related formins (DRFs). DRFs activated by RHO GTPases contain a GTPase binding domain (GBD) at their N-terminus, followed by formin homology domains 3, 1, and 2 (FH3, FH1, FH2) and a diaphanous autoregulatory domain (DAD) at the C-terminus. Most DRFs contain a dimerization domain (DD) and a coiled-coil region (CC) in between FH3 and FH1 domains (reviewed by Kuhn and Geyer 2014). RHO GTPase-activated DRFs are autoinhibited through the interaction between FH3 and DAD which is disrupted upon binding to an active RHO GTPase (Li and Higgs 2003, Lammers et al. 2005, Nezami et al. 2006). Since formins dimerize, it is not clear whether the FH3-DAD interaction is intra- or intermolecular. FH2 domain is responsible for binding to the F-actin and contributes to the formation of head-to-tail formin dimers (Xu et al. 2004). The proline-rich FH1 domain interacts with the actin-binding proteins profilins, thereby facilitating actin recruitment to formins and accelerating actin polymerization (Romero et al. 2004, Kovar et al. 2006). Different formins are activated by different RHO GTPases in different cell contexts. FMNL1 (formin-like protein 1) is activated by binding to the RAC1:GTP and is involved in the formation of lamellipodia in macrophages (Yayoshi-Yamamoto et al. 2000) and is involved in the regulation of the Golgi complex structure (Colon-Franco et al. 2011). Activation of FMNL1 by CDC42:GTP contributes to the formation of the phagocytic cup (Seth et al. 2006). Activation of FMNL2 (formin-like protein 2) and FMNL3 (formin-like protein 3) by RHOC:GTP is involved in cancer cell motility and invasiveness (Kitzing et al. 2010, Vega et al. 2011). DIAPH1, activated by RHOA:GTP, promotes elongation of actin filaments and activation of SRF-mediated transcription which is inhibited by unpolymerized actin (Miralles et al. 2003). RHOF-mediated activation of DIAPH1 is implicated in formation of stress fibers (Fan et al. 2010). Activation of DIAPH1 and DIAPH3 by RHOB:GTP leads to actin coat formation around endosomes and regulates endosome motility and trafficking (Fernandez-Borja et al. 2005, Wallar et al. 2007). Endosome trafficking is also regulated by DIAPH2 transcription isoform 3 (DIAPH2-3) which, upon activation by RHOD:GTP, recruits SRC kinase to endosomes (Tominaga et al. 2000, Gasman et al. 2003). DIAPH2 transcription isoform 2 (DIAPH2-2) is involved in mitosis where, upon being activated by CDC42:GTP, it facilitates the capture of astral microtubules by kinetochores (Yasuda et al. 2004, Cheng et al. 2011). DIAPH2 is implicated in ovarian maintenance and premature ovarian failure (Bione et al. 1998). DAAM1, activated by RHOA:GTP, is involved in linking WNT signaling to cytoskeleton reorganization (Habas et al. 2001)."
BMGC_PW1415,BMG_PW4040,,,"Rhotekin (RTKN) is a protein with an N-terminally located RHO GTPase binding domain, that shares a limited sequence homology with PKNs and rhophilins. RTKN binds to GTP-bound RHOA, RHOB and RHOC and can inhibit their GTPase activity (Reid et al. 1996, Fu et al. 2000), which can be corroborated by protein kinase D-mediated phosphorylation of RTKN (Pusapati et al. 2012). RTKN is implicated in the establishment of cell polarity (Sudo et al. 2006), septin organization (Ito et al. 2005, Sudo et al. 2007) and stimulation of SRF-mediated transcription (Reynaud et al. 2000). RTKN can have an anti-apoptotic effect that depends on the activation of NFKB (NF-kappaB) (Liu et al. 2004). RTKN2 (rhotekin-2) is another rhotekin exclusively expressed in lymphocytes (Collier et al. 2004). The function and the mechanism of action of RTKN2 are unknown. Rhophillins include two family members - rhophilin-1 (RHNP1) and rhophilin-2 (RHPN2) with ~75% sequence identity. A RHO GTPase binding domain is located at the N-terminus of rhophilins, followed by a BRO1 domain (characteristic of proteins involved in protein kinase C signaling) and a C-terminal PDZ domain. RHOA:GTP binds both RHPN1 and RHPN2 and these interactions may be involved in organization of the actin cytoskeleton and/or cell motility (Watanabe et al. 1996, Fujita et al. 2000, Peck et al. 2002). RHOB:GTP recruits RHPN2 to endosomes which may be involved in the function of thyroid cells (Mircescu et al. 2002)."
BMGC_PW1416,BMG_PW4041,,,"Tumor necrosis factor-alpha (TNFA) exerts a wide range of biological effects through TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2). Under normal physiological conditions TNFR2 exhibits more restricted expression, being found on certain subpopulation of immune cells and few other cell types (Grell et al. 1995 ). TNFR1 mediated signalling pathways have been very well characterized but, TNFR2 has been much less well studied. TNFR1 upon activation by TNFA activates apoptosis through two pathways, involving the adaptor proteins TNFR1-associated death domain (TRADD) and fas-associated death domain (FADD). In contrast, TNFR2 signalling especially in highly activated T cells, induces cell survival pathways that can result in cell proliferation by activating transcription factor NF-kB (nuclear factor-kB) via the alternative non-canonical route. TNFR2 signalling seems to play an important role, in particular for the function of regulatory T cells. It offers protective roles in several disorders, including autoimmune diseases, heart diseases, demyelinating and neurodegenerative disorders and infectious diseases (Faustman & Davis 2010). Activation of the non-canonical pathway by TNFR2 is mediated through a signalling complex that includes TNF receptor-associated factor (TRAF2 and TRAF3), cellular inhibitor of apoptosis (cIAP1 and cIAP2), and NF-kB-inducing kinase (NIK). In this complex TRAF3 functions as a bridging factor between the cIAP1/2:TRAF2 complex and NIK. In resting cells cIAP1/2 in the signalling complex mediates K48-linked polyubiquitination of NIK and subsequent proteasomal degradation making NIK levels invisible. Upon TNFR2 stimulation, TRAF2 is recruited to the intracellular TRAF binding motif and this also indirectly recruits TRAF1 and cIAP1/2, as well as TRAF3 and NIK which are already bound to TRAF2 in unstimulated cells. TRAF2 mediates K63-linked ubiquitination of cIAP1/2 and this in turn mediates cIAP dependent K48-linked ubiquitination of TRAF3 leading to the proteasome-dependent degradation of the latter. As TRAF3 is degraded, NIK can no longer interact with TRAF1/2:cIAP complex. As a result NIK concentration in the cytosol increases and NIK gets stabilised and activated. Activated NIK phosphorylates IKKalpha, which in turn phosphorylates p100 (NFkB2) subunit. Phosphorylated p100 is also ubiquitinated by the SCF-beta-TRCP ubiquitin ligase complex and is subsequently processed by the proteaseome to p52, which is a transcriptionally competent NF-kB subunit in conjunction with RelB (Petrus et al. 2011, Sun 2011, Vallabhapurapu & Karin 2009)."
BMGC_PW1417,BMG_PW4042,,,"NADPH oxidases (NOX) are membrane-associated enzymatic complexes that use NADPH as an electon donor to reduce oxygen and produce superoxide (O2-) that serves as a secondary messenger (Brown and Griendling 2009). NOX2 complex consists of CYBB (NOX2), CYBA (p22phox), NCF1 (p47phox), NCF2 (p67phox) and NCF4 (p40ohox). RAC1:GTP binds NOX2 complex in response to VEGF signaling by directly interracting with CYBB and NCF2, leading to enhancement of VEGF-signaling through VEGF receptor VEGFR2, which plays a role in angiogenesis (Price et al. 2002, Bedard and Krause 2007). RAC2:GTP can also activate the NOX2 complex by binding to CYBB and NCF2, leading to production of superoxide in phagosomes of neutrophils which is necessary fo the microbicidal activity of neutrophils (Knaus et al. 1991, Roberts et al. 1999, Kim and Dinauer 2001, Jyoti et al. 2014). NOX1 complex (composed of NOX1, NOXA1, NOXO1 and CYBA) and NOX3 complex (composed of NOX3, CYBA, NCF1 amd NCF2 or NOXA1) can also be activated by binding to RAC1:GTP to produce superoxide (Cheng et al. 2006, Miyano et al. 2006, Ueyama et al. 2006)."
BMGC_PW1418,BMG_PW4043,,,"Members of the tumour necrosis factor superfamily (TNFSF) and TNF receptor superfamily (TNFRSF) have crucial roles in both innate and adaptive immunity. These members are implicated in various acquired or genetic human diseases, ranging from septic shock to autoimmune disorders, allograft rejection and cancer (So et al. 2006)."
BMGC_PW1419,BMG_PW4044,,,"Mammals have three RAF isoforms, A, B and C, that are activated downstream of RAS and stimulate the MAPK pathway. Although CRAF (also known as RAF-1) was the first identified and remains perhaps the best studied, BRAF is most similar to the RAF expressed in other organisms. Notably, MAPK (ERK) activation is more compromised in BRAF-deficient cells than in CRAF or ARAF deficient cells (Bonner et al, 1985; Mikula et al, 2001, Huser et al, 2001, Mercer et al, 2002; reviewed in Leicht et al, 2007; Matallanas et al, 2011; Cseh et al, 2014). Consistent with its important role in MAPK pathway activation, mutations in the BRAF gene, but not in those for A- or CRAF, are associated with cancer development (Davies et al, 2002; reviewed in Leicht et al, 2007). ARAF and CRAF may have arisen through gene duplication events, and may play additional roles in MAPK-independent signaling (Hindley and Kolch, 2002; Murakami and Morrison, 2001). Despite divergences in function, all mammalian RAF proteins share three conserved regions (CRs) and each interacts with RAS and MEK proteins, although with different affinities. The N-terminal CR1 contains a RAS-binding domain (RBD) and a cysteine-rich domain (CRD) that mediate interactions with RAS and the phospholipid membrane. CR2 contains inhibitory phosphorylation sites that impact RAS binding and RAF activation, while the C-terminal CR3 contains the bi-lobed kinase domain with its activation loop, and an adjacent upstream ""N-terminal acidic motif"" -S(S/G)YY in C- and A-RAF,respectively, and SSDD in B-RAF - that is required for RAF activation (Tran et al, 2005; Dhillon et al, 2002; Chong et al, 2001; Cutler et al, 1998; Chong et al, 2003; reviewed in Matallanas et al, 2011). Regulation of RAF activity involves multiple phosphorylation and dephosphorylation events, intramolecular conformational changes, homo- and heterodimerization between RAF monomers and changes to protein binding partners, including scaffolding proteins which bring pathway members together (reviewed in Matallanas et al, 2011; Cseh et al, 2014). The details of this regulation are not completely known and differ slightly from one RAF isoform to another. Briefly, in the inactive state, RAF phosphorylation on conserved serine residues in CR2 promote an interaction with 14-3-3 dimers, maintaining the kinase in a closed conformation. Upon RAS activation, these sites are dephosphorylated, allowing the RAF CRD and RBD to bind RAS and phospholipids, facilitating membrane recruitment. RAF activation requires homo- or heterodimerization, which promotes autophosphorylation in the activation loop of the receiving monomer. Of the three isoforms, only BRAF is able to initiate this allosteric activation of other RAF monomers (Hu et al, 2013; Heidorn et al, 2010; Garnett et al, 2005). This activity depends on negative charge in the N-terminal acidic region (NtA; S(S/G)YY or SSDD) adjacent to the kinase domain. In BRAF, this region carries permanent negative charge due to the presence of the two aspartate residues in place of the tyrosine residues of A- and CRAF. In addition, unique to BRAF, one of the serine residues of the NtA is constitutively phosphorylated. In A- and CRAF, residues in this region are subject to phosphorylation by activated MEK downstream of RAF activation, establishing a positive feedback loop and allowing activated A- and CRAF monomers to act as transactivators in turn (Hu et al, 2013; reviewed in Cseh et al, 2014). RAF signaling is terminated through dephosphorylation of the NtA region and phosphorylation of the residues that mediate the inhibitory interaction with 14-3-3, promoting a return to the inactive state (reviewed in Matallanas et al, 2011; Cseh et al, 2014)."
BMGC_PW1420,BMG_PW4045,,,"The RAS-RAF-MEK-ERK pathway regulates processes such as proliferation, differentiation, survival, senescence and cell motility in response to growth factors, hormones and cytokines, among others. Binding of these stimuli to receptors in the plasma membrane promotes the GEF-mediated activation of RAS at the plasma membrane and initiates the three-tiered kinase cascade of the conventional MAPK cascades. GTP-bound RAS recruits RAF (the MAPK kinase kinase), and promotes its dimerization and activation (reviewed in Cseh et al, 2014; Roskoski, 2010; McKay and Morrison, 2007; Wellbrock et al, 2004). Activated RAF phosphorylates the MAPK kinase proteins MEK1 and MEK2 (also known as MAP2K1 and MAP2K2), which in turn phophorylate the proline-directed kinases ERK1 and 2 (also known as MAPK3 and MAPK1) (reviewed in Roskoski, 2012a, b; Kryiakis and Avruch, 2012). Activated ERK proteins may undergo dimerization and have identified targets in both the nucleus and the cytosol; consistent with this, a proportion of activated ERK protein relocalizes to the nucleus in response to stimuli (reviewed in Roskoski 2012b; Turjanski et al, 2007; Plotnikov et al, 2010; Cargnello et al, 2011). Although initially seen as a linear cascade originating at the plasma membrane and culminating in the nucleus, the RAS/RAF MAPK cascade is now also known to be activated from various intracellular location. Temporal and spatial specificity of the cascade is achieved in part through the interaction of pathway components with numerous scaffolding proteins (reviewed in McKay and Morrison, 2007; Brown and Sacks, 2009). The importance of the RAS/RAF MAPK cascade is highlighted by the fact that components of this pathway are mutated with high frequency in a large number of human cancers. Activating mutations in RAS are found in approximately one third of human cancers, while ~8% of tumors express an activated form of BRAF (Roberts and Der, 2007; Davies et al, 2002; Cantwell-Dorris et al, 2011)."
BMGC_PW1421,BMG_PW4046,,,"Activated RAF proteins are restricted substrate kinases whose primary downstream targets are the two MAP2K proteins, MAPK2K1 and MAP2K2 (also known as MEK1 and MEK2) (reviewed in Roskoski, 2010, Roskoski, 2012a). Phosphorylation of the MAPK2K activation loop primes them to phosphorylate the primary effector of the activated MAPK pathway, the two MAPK proteins MAPK3 and MAPK1 (also known as ERK1 and 2). Unlike their upstream counterparts, MAPK3 and MAPK1 catalyze the phosphorylation of hundreds of cytoplasmic and nuclear targets including transcription factors and regulatory molecules (reviewed in Roskoski, 2012b). Activation of MAP2K and MAPK proteins downstream of activated RAF generally occurs in the context of a higher order scaffolding complex that regulates the specificity and localization of the pathway (reviewed in Brown and Sacks, 2009; Matallanas et al, 2011)."
BMGC_PW1422,BMG_PW4047,,,"While AKT1 gene copy number, expression level and phosphorylation are often increased in cancer, only one low frequency point mutation has been repeatedly reported in cancer and functionally studied. This mutation represents a substitution of a glutamic acid residue with lysine at position 17 of AKT1, and acts by enabling AKT1 to bind PIP2. PIP2-bound AKT1 is phosphorylated by TORC2 complex and by PDPK1 that is always present at the plasma membrane, due to low affinity for PIP2. Therefore, E17K substitution abrogates the need for PI3K in AKT1 activation (Carpten et al. 2007, Landgraf et al. 2008)."
BMGC_PW1423,BMG_PW4049,,,"MAPK pathway activation is limited by a number of negative feedback loops established by MAPK-dependent phosphorylations. Known substrates of activated MAPK proteins that lie upstream in the RAF/MAPK pathway include SOS, RAF1, BRAF, and MAP2K1 (Buday et al, 1995; Dong et al, 1996; Dougherty et al, 2005; Sturm et al, 2010; Fritsche-Guenther et al, 2011; Rushworth et al, 2006; Brummer et al, 2003; Ritt et al, 2010; Catalanotti et al, 2009)"
BMGC_PW1424,BMG_PW4050,,,"The duration and extent of activated MAPK signaling is regulated at many levels through mechanisms that include phosphorylation and dephosphorylation, changes to protein interacting partners and subcellular localization (reviewed in Matallanas et al, 2011). Activated RAF proteins are subject to MAPK-dependent phosphorylation that promotes the subsequent dephosphorylation of the activation loop and NtA region, terminating RAF kinase activity. This dephosphorylation, catalyzed by PP2A and PP5, primes the RAF proteins for PKA or AKT-mediated phosphorylation of residues S259 and S621, restoring the 14-3-3 binding sites and returning the RAF proteins to the inactive state (von Kriegsheim et al, 2006; Dougherty et al, 2005; reviewed in Matallanas et al, 2011). The phosphorylated RAF1 NtA is also subject to additional regulation through binding to the PEBP1 protein, which promotes its dissociation from MAP2K substrates (Shin et al, 2009). Activated MAPK proteins also phosphorylate T292 of MAP2K1; this phosphorylation limits the activity of MAP2K1, and indirectly affects MAP2K2 activity through by modulating the activity of the MAP2K heterodimer (Catalanotti et al, 2009; reviewed in Matallanas et al, 2011). Dephosphorylation of MAPKs by the dual specificity MAPK phosphatases (DUSPs) plays a key role in limiting the extent of pathway activation (Owens et al, 2007; reviewed in Roskoski, 2012b). Class I DUSPs are localized in the nucleus and are induced by activation of the MAPK pathway, establishing a negative feedback loop, while class II DUSPs dephosphorylate cytoplasmic MAPKs (reviewed in Rososki, 2012b). MAPK signaling is also regulated by the RAS GAP-mediated stimulation of intrinsic RAS GTPase activity which returns RAS to the inactive, GDP bound state (reviewed in King et al, 2013)."
BMGC_PW1425,BMG_PW4051,,"Necroptosis is a programmed form of necrosis. It can be initiated by different stimuli, such as tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL), Fas ligand (FasL), interferon (IFN), LPS, viral DNA or RNA, DNA-damage agent and requires the kinase activity of receptor-interacting protein 1 (RIPK1) and RIPK3. Its execution involves ROS generation, calcium overload, the opening of the mitochondrial permeability transition pore, mitochondrial fission, inflammatory response and chromatinolysis. Necroptosis participates in many pathogenesis of diseases, including neurological diseases, retinal disorders, acute kidney injury, inflammatory diseases and microbial infections.","A regulated balance between cell survival and cell death is essential for normal development and homeostasis of multicellular organisms. Defects in control of this balance may contribute to autoimmune disease, neurodegeneration, ischemia/reperfusion injury, non alcoholic steatohepatitis (NASH) and cancer."
BMGC_PW1426,BMG_PW4052,,,"In addition to the activation of canonical NF-kB subunits, activation of SYK pathway by Dectin-1 leads to the induction of the non-canonical NF-kB pathway, which mediates the nuclear translocation of RELB-p52 dimers through the successive activation of NF-kB-inducing kinase (NIK) and IkB kinase-alpha (IKKa) (Geijtenbeek & Gringhuis 2009, Gringhuis et al. 2009). Noncanonical activity tends to build more slowly and remain sustained several hours longer than does the activation of canonical NF-kB. The noncanonical NF-kB pathway is characterized by the post-translational processing of NFKB2 (Nuclear factor NF-kappa-B) p100 subunit to the mature p52 subunit. This subsequently leads to nuclear translocation of p52:RELB (Transcription factor RelB) complexes to induce cytokine expression of some genes (C-C motif chemokine 17 (CCL17) and CCL22) and transcriptional repression of others (IL12B) (Gringhuis et al. 2009, Geijtenbeek & Gringhuis 2009, Plato et al. 2013)."
BMGC_PW1427,BMG_PW4053,,,"Activation of NF-kB is fundamental to signal transduction by members of the TNFRSF. Expression of NF-kB target genes is essential for mounting innate immune responses to infectious microorganisms but is also important for the proper development and cellular compartmentalization of secondary lymphoid organs necessary to orchestrate an adaptive immune response. NF-kB transcription factor family is activated by two distinct pathways: the canonical pathway involving NF-kB1 and the non-canonical pathway involving NF-kB2. Unlike NF-kB1 signalling, which can be activated by a wide variety of receptors, the NF-kB2 pathway is typically activated by a subset of receptor and ligand pairs belonging to the tumor necrosis factor receptor (TNF) super family (TNFRSF) members. These members include TNFR2 (Rauert et al. 2010), B cell activating factor of the TNF family receptor (BAFFR also known as TNFRSF13C) (Kayagaki et al. 2002, CD40 (also known as TNFRSF5) (Coope et al. 2002, lymphotoxin beta-receptor (LTBR also known as TNFRSF3) (Dejardin et al. 2002), receptor activator for nuclear factor kB (RANK also known as TNFRSF11A) (Novack et al. 2003), CD27 and Fibroblast growth factor-inducible immediate-early response protein 14 (FN14 also known as TNFRSF12A) etc. These receptors each mediate specific biological roles of the non-canonical NF-kB. These non-canonical NF-kB-stimulating receptors have one thing in common and is the presence of a TRAF-binding motif, which recruits different TNF receptor-associated factor (TRAF) members, particularly TRAF2 and TRAF3, to the receptor complex during ligand ligation (Grech et al. 2004, Bishop & Xie 2007). Receptor recruitment of these TRAF members leads to their degradation which is a critical step leading to the activation of NIK and induction of p100 processing (Sun 2011, 2012)."
BMGC_PW1428,BMG_PW4054,,,"Reactive oxygen species (ROS) such as H2O2, superoxide anions and hydroxyl radicals interact with molecules in the cell causing damage that impairs cellular functions. Although cells have mechanisms to destroy ROS and repair the damage caused by ROS, it is considered to be a major factor in age-related diseases and the ageing process (Zhang & Weissbach 2008, Kim et al. 2014). ROS-scavenging systems include enzymes such as peroxiredoxins, superoxide dismutases, catalases and glutathione peroxidases exist to minimise the potential damage. ROS reactions can also cause specific modifications to amino acid side chains that result in structural changes to proteins/enzymes. Methionine (Met) and cysteine (Cys) can be oxidised by ROS to sulfoxide and further oxidised to sulfone derivatives. Both free Met and protein-based Met are readily oxidized to form methionine sulphoxide (MetO) (Brot & Weissbach 1991). Many proteins have been demonstrated to undergo such oxidation and as a consequence have altered function (Levine et al. 2000). Sulphoxide formation can be reversed by the action of the methionine sulphoxide reductase system (MSR) which catalyses the reduction of MetO to Met (Brot et al. 1981). This repair uses one ROS equivalent, so MSR proteins can act as catalytic antioxidants, removing ROS (Levine et al. 1996). Methionine oxidation results in a mixture of methionine (S)-S- and (R)-S-oxides of methionine, diastereomers which are reduced by MSRA and MSRB, respectively. MSRA can reduce both free and protein-based methionine-(S)-S-oxide, whereas MSRB is specific for protein-based methionine-(R)-S-oxide. Mammals typically have only one gene encoding MSRA, but at least three genes encoding MSRBs (Hansel et al. 2005). Although structurally distinct, MRSA and MRSB share a common three-step catalytic mechanism. In the first step, the MSR catalytic cysteine residue interacts with the MetO substrate, which leads to product release and formation of the sulfenic acid. In the second step, an intramolecular disulfide bridge is formed between the catalytic cysteine and the regenerating cysteine. In the final step, the disulfide bridge is reduced by an electron donor, the NADPH-dependent thioredoxin/TR system, leading to the regeneration of the MSR active site (Boschi-Muller et al. 2008). Beta-linked isoaspartyl (isoAsp) peptide bonds can arise spontaneously via succinimide-linked deamidation of asparagine (Asn) or dehydration of aspartate (Asp). Protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1, PIMT EC 2.1.1.77) transfers the methyl group from S-adenosyl-L-methionine (AdoMet) to the alpha side-chain carboxyl group of L-isoaspartyl and D-aspartatyl amino acids. The resulting methyl ester undergoes spontaneous transformation to L-succinimide, which spontaneously hydrolyses to generates L-aspartyl residues or L-isoaspartyl residues (Knorre et al. 2009). This repair process helps to maintain overall protein integrity."
BMGC_PW1429,BMG_PW4058,,,"Cystic fibrosis transmembrane conductance regulator (CFTR) is a low conductance chloride-selective channel that mediates the transport of chloride ions in human airway epithelial cells. Chloride ions plays a key role in maintaining homoeostasis of epithelial secretions in the lungs. Defects in CFTR can cause cystic fibrosis (CF; MIM:602421), a common generalised disorder in Caucasians affecting the exocrine glands. CF results in an ionic imbalance that impairs clearance of secretions, not only in the lung, but also in the pancreas, gastrointestinal tract and liver. Wide-ranging manifestations of the disease include chronic lung disease, exocrine pancreatic insufficiency, blockage of the terminal ileum, male infertility and salty sweat. The median survival of CF patients in North America and Western Europe is around 40 years (Davis 2006, Radlovic 2012)."
BMGC_PW1430,BMG_PW4064,,,"Synapse formation and maturation require multiple interactions between presynaptic and postsynaptic neurons. These interactions are mediated by a diverse set of synaptogenic proteins (Kegel et al. 2013, Siddiqui & Craig 2011). Initial synapse formation needs both the binding of secreted proteins to presynaptic and postsynaptic receptors, and the direct binding between presynaptic and postsynaptic transmembrane proteins. One class of molecules that plays an important role in cellular interactions in nervous system development and function is the leucine-rich glioma inactivated (LGI) protein family. These are secreted synaptogenic proteins consisting of an LRR (leucine-rich repeat) domain and a epilepsy-associated or EPTP (epitempin) domain (Gu et al. 2002). Both protein domains are generally involved in protein-protein interactions. Genetic and biochemical evidence suggests that the mechanism of action of LGI proteins involves binding to a subset of cell surface receptors belonging to the ADAM (a disintegrin and metalloproteinase) family, i.e. ADAM11, ADAM22 and ADAM23. These interactions play crucial role in the development and function of the vertebrate nervous system mainly mediating synaptic transmission and myelination (Kegel et al. 2013, Novak 2004, Seals & Courtneidge 2003)."
BMGC_PW1431,BMG_PW4065,,,"ATP-binding cassette sub-family C member 8 (ABCC8) is a subunit of the beta-cell ATP-sensitive potassium channel (KATP). KATP channels play an important role in the control of insulin release. Elevation of the ATP:ADP ratio closes KATP channels leading to cellular depolarisation, calcium influx and exocytosis of insulin from its storage granules. Defects in ABCC8 can cause dysregulation of insulin secretion resulting in hyperglycemias or hypoglycemias. Specific phenotypes observed are noninsulin-dependent diabetes mellitus (NIDDM; MIM:125853), permanent neonatal diabetes mellitus (PNDM; MIM:606176), transient neonatal diabetes mellitus 2 (TNDM2; MIM:610374), familial hyperinsulinemic hypoglycemia 1 (HHF1; MIM:256450) and leucine-induced hypoglycemia (LIH; MIM:240800) (Edghill et al. 2010, Flanagan et al. 2009, Yorifuji 2014, Yang et al. 2010, Chandran et al. 2014)."
BMGC_PW1432,BMG_PW4068,,,"ATP-binding cassette sub-family A member 3 (ABCA3) is thought to play a role in the formation of pulmonary surfactant by transporting lipids such as cholesterol into lamellar bodies (LBs) in alveolar type II cells. In LBs, surfactant proteins and lipids are assembled into bilayer membranes that are secreted into the alveolar airspace, where they form a surface film at the air–liquid interface. Defects in ABCA3 can cause pulmonary surfactant metabolism dysfunction 3 (SMDP3), a usually fatal pulmonary disease in newborns, characterised by the absence of normal LBs and the presence of electron-dense inclusions within small vesicular structures. Loss of secretion of lipid pulmonary surfactants causes excessive lipoprotein accumulation in the alveoli resulting in severe respiratory distress (Shulenin et al. 2004, Quazi & Molday 2011, Tarling et al. 2014, Whitsett et al. 2015)."
BMGC_PW1433,BMG_PW4069,,,"The alveolar region of the lung creates an extensive epithelial surface that mediates the transfer of oxygen and carbon dioxide required for respiration after birth. Type I epithelial cells form the alveolar surface and mediate gaseous exchange. Type II epithelial cells secrete pulmonary surfactant, a lipoprotein complex that forms a thin interfacial film, lowering surface tension at the air-liquid interface in alveoli and maintaining the structural integrity of alveoli, preventing their collapse at low volumes (Agassandian & Mallampalli 2013). Surfactant production is increased prior to birth, in preparation for air breathing at birth (Hallman 2013). Pre-term infants, where type II epithelial cells are not fully differentiated yet, can produce insufficient surfactant and result in respiratory distress syndrome. Surfactant is composed primarily of phospholipids enriched in phosphatidylcholine (PC) and phosphatidylglycerol (PG) (Agassandian & Mallampalli 2013) and the pulmonary collectins, termed surfactant proteins A, B, C and D (SFTPA-D). They influence surfactant homeostasis, contributing to the physical structures of lipids in the alveoli and to the regulation of surfactant function and metabolism. They are directly secreted from alveolar type II cells into the airway to function as part of the surfactant. SFTPA and D are large, hydrophilic proteins while SFTPB and C are small, very hydrophobic proteins (Johansson et al. 1994). In addition to their surfactant functions, SFTPA and D play important roles in innate host defense by binding and clearing invading microbes from the lung (Kingma & Whitsett 2006). Nuclear regulation, transport, metabolism, reutilisation and degradation of surfactant are described here (Ikegami 2006, Boggaram 2009, Whitsett et al. 2010). Mutations in genes involved in these processes can result in respiratory distress syndrome, lung proteinosis, interstitial lung diseases and chronic lung diseases (Perez-Gil & Weaver 2010, Whitsett et al. 2010, Akella & Deshpande 2013, Jo 2014)."
BMGC_PW1434,BMG_PW4071,,,"Tumor progression locus-2 (TPL2, also known as COT and MAP3K8) functions as a mitogen-activated protein kinase (MAPK) kinase kinase (MAP3K) in various stress-responsive signaling cascades. MAP3K8 (TPL2) mediates phosphorylation of MAP2Ks (MEK1/2) which in turn phosphorylate MAPK (ERK1/2) (Gantke T et al., 2011). In the absence of extra-cellular signals, cytosolic MAP3K8 (TPL2) is held inactive in the complex with ABIN2 (TNIP2) and NFkB p105 (NFKB1) (Beinke S et al., 2003; Waterfield MR et al., 2003; Lang V et al., 2004). This interaction stabilizes MAP3K8 (TPL2) but also prevents MAP3K8 and NFkB from activating their downstream signaling cascades by inhibiting the kinase activity of MAP3K8 and the proteolysis of NFkB precursor protein p105. Upon activation of MAP3K8 by various stimuli (such as LPS, TNF-alpha, and IL-1 beta), IKBKB phosphorylates NFkB p105 (NFKB1) at Ser927 and Ser932, which trigger p105 proteasomal degradation and releases MAP3K8 from the complex (Beinke S et al., 2003, 2004; Roget K et al., 2012). Simultaneously, MAP3K8 is activated by auto- and/or transphosphorylation (Gantke T et al. 2011; Yang HT et al. 2012). The released active MAP3K8 phosphorylates its substrates, MAP2Ks. The free MAP3K8, however, is also unstable and is targeted for proteasome-mediated degradation, thus restricting prolonged activation of MAP3K8 (TPL2) and its downstream signaling pathways (Waterfield MR et al. 2003; Cho J et al., 2005). Furthermore, partially degraded NFkB p105 (NFKB1) into p50 can dimerize with other NFkB family members to regulate the transcription of target genes. MAP3K8 activity is thought to regulate the dynamics of transcription factors that control an expression of diverse genes involved in growth, differentiation, and inflammation. Suppressing the MAP3K8 kinase activity with selective inhibitors, such as C8-chloronaphthyridine-3-carbonitrile, caused a significant reduction in TNFalpha production in LPS- and IL-1beta-induced both primary human monocytes and human blood (Hall JP et al. 2007). Similar results have been reported for mouse LPS-stimulated RAW264.7 cells (Hirata K et al. 2010). Moreover, LPS-stimulated macrophages derived from Map3k8 knockout mice secreted lower levels of pro-inflammatory cytokines such as TNFalpha, Cox2, Pge2 and CXCL1 (Dumitru CD et al. 2000; Eliopoulos AG et al. 2002). Additionally, bone marrow-derived dendritic cells (BMDCs) and macrophages from Map3k8 knockout mice showed significantly lower expression of IL-1beta in response to LPS, poly IC and LPS/MDP (Mielke et al., 2009). However, several other studies seem to contradict these findings and Map3k8 deficiency in mice has been also reported to enhance pro-inflammatory profiles. Map3k8 deficiency in LPS-stimulated macrophages was associated with an increase in nitric oxide synthase 2 (NOS2) expression (López-Peláez et al., 2011). Similarly, expression of IRAK-M, whose function is to compete with IL-1R-associated kinase (IRAK) family of kinases, was decreased in Map3k8-/- macrophages while levels of TNF and IL6 were elevated (Zacharioudaki et al., 2009). Moreover, significantly higher inflammation level was observed in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated Map3k8-/- mouse skin compared to WT skin (DeCicco-Skinner K. et al., 2011). Additionally, MAP3K8 activity is associated with NFkB inflammatory pathway. High levels of active p65 NFkB were observed in the nucleus of Map3k8 -/- mouse keratinocytes that dramatically increased within 15-30 minutes of TPA treatment. Similarly, increased p65 NFkB was observed in Map3k8-deficient BMDC both basally and after stimulation with LPS when compared to wild type controls (Mielke et al., 2009). The data opposes the findings that Map3k8-deficient mouse embryo fibroblasts and human Jurkat T cells with kinase domain-deficient protein have a reduction in NFkB activation but only when certain stimuli are administered (Lin et al., 1999; Das S et al., 2005). Thus, it is possible that whether MAP3K8 serves more of a pro-inflammatory or anti-inflammatory role may depend on cell- or tissue type and on stimuli (LPS vs. TPA, etc.) (Mielke et al., 2009; DeCicco-Skinner K. et al., 2012). MAP3K8 has been also studied in the context of carcinogenesis, however the physiological role of MAP3K8 in the etiology of human cancers is also convoluted (Vougioukalaki M et al., 2011; DeCicco-Skinner K. et al., 2012)."
BMGC_PW1435,BMG_PW4072,,,"The extracellular signal regulated kinases (ERKs) 1 and 2, also known as MAPK3 and MAPK1, are phosphorylated by the MAP2Ks 1 and 2 in response to a wide range of extracellular stimuli to promote differentiation, proliferation, cell motility, cell survivial, metabolism and transcription, among others (reviewed in Roskoski, 2012b; McKay and Morrison, 2007; Raman et al, 2007). In the classical pathway, MAPK1/3 activation is triggered by the GEF-mediated activation of RAS at the plasma membrane, leading to the activation of the RAF MAP3Ks (reviewed in McKay and Morrison, 2007; Matallanas et al, 2011; Wellbrock et al, 2004). However, many physiological and pathological stimuli have been found to activate MAPK1/3 independently of RAF and RAS, acting instead through MAP3Ks such as MOS, TPL2 and AMPK (Dawson et al, 2008; Wang et al, 2009; Kuriakose et al, 2014; Awane et al, 1999). Activated MAPK1/3 phosphorylate numerous targets in both the nucleus and cytoplasm (reviewed in Yoon and Seger, 2006; Roskoski 2012b)."
BMGC_PW1436,BMG_PW4073,,,"Homology directed repair (HDR) through single strand annealing (SSA), similar to HDR through homologous recombination repair (HRR), involves extensive resection of DNA double-strand break ends (DSBs), preceded by ATM activation and formation of the so-called ionizing radiation induced foci (IRIF) at DNA DSB sites. Following ATM activation and foci formation, the two-step resection is initiated by the MRN complex (MRE11A:RAD50:NBN) and RBBP8 (CtIP) associated with BRCA1:BARD1, and completed by EXO1 or DNA2 in cooperation with DNA helicases BLM, WRN and BRIP1 (BACH1) (Sartori et al. 2007, Yun and Hiom 2009, Eid et al. 2010, Nimonkar et al. 2011, Suhasini et al. 2011, Sturzenegger et al. 2014). Long 3'-ssDNA overhangs produced by extensive resection are coated by the RPA heterotrimer (RPA1:RPA2:RPA3), triggering ATR signaling. ATR signaling is needed for SSA, probably because of the related phosphorylation of RPA2 (Zou and Elledge 2003, Anantha et al. 2007, Liu et al. 2012). RAD52 is the key mediator of SSA. Activated ATM phosphorylates and activates ABL1, and activated ABL1 subsequently phosphorylates pre-formed RAD52 heptameric rings, increasing their affinity for ssDNA (Honda et al. 2011). Phosphorylated RAD52 binds phosphorylated RPA heterotrimers on 3'-ssDNA overhangs at resected DNA DSBs. RAD52 also binds RAD51 and prevents formation of invasive RAD51 nucleofilaments involved in HRR (Chen et al. 1999, Van Dyck et al. 1999, Parsons et al. 2000, Jackson et al. 2002, Singleton et al. 2002). RAD52 promotes annealing of two 3'-ssDNA overhangs when highly homologous directed repeats are present in both 3'-ssDNA overhangs. Nonhomologous regions lying 3' to the annealed repeats are displaced as 3'-flaps (Parsons et al. 2000, Van Dyck et al. 2001, Singleton et al. 2002, Stark et al. 2004, Mansour et al. 2008). The endonuclease complex composed of ERCC1 and ERCC4 (XPF) is subsequently recruited to SSA sites through direct interaction between RAD52 and ERCC4, leading to cleavage of 3' flaps (Motycka et al. 2004, Al-Minawi et al. 2008). The identity of a DNA ligase that closes the remaining single strand nicks (SSBs) to complete SSA-mediated repair is not known. SSA results in deletion of one of the annealed repeats and the intervening DNA sequence between the two annealed repeats and is thus mutagenic."
BMGC_PW1437,BMG_PW4074,,,
BMGC_PW1438,BMG_PW4075,,,"Homology directed repair (HDR) through homologous recombination is known as homologous recombination repair (HRR). HRR occurs after extensive resection of DNA double-strand break (DSB) ends, which creates long 3'-ssDNA overhangs. RAD51 coats 3'-ssDNA overhangs in a BRCA2-controlled fashion, creating invasive RAD51 nucleofilaments. The RAD51 nucleofilament invades a sister chromatid DNA duplex, leading to D-loop formation. After the D-loop is extended by DNA repair synthesis, the resulting recombination intermediates in the form of extended D-loops or double Holliday junctions can be resolved through crossover- or non-crossover-generating processes (reviewed by Ciccia and Elledge 2010)."
BMGC_PW1439,BMG_PW4076,,,"Diverse molecules of host-cell origin may serve as endogenous ligands of Toll-like receptors (TLRs) (Erridge C 2010; Piccinini AM & Midwood KS 2010). These molecules are known as damage-associated molecular patterns (DAMPs). DAMPs are immunologically silent in healthy tissues but become active upon tissue damage during both infectious and sterile insult. DAMPs are released from necrotic cells or secreted from activated cells in response to tissue damage to mediate tissue repair by promoting inflammatory responses. However, DAMPs have also been implicated in the pathogenesis of many inflammatory and autoimmune diseases, including rheumatoid arthritis (RA), cancer, and atherosclerosis. The mechanism underlying the switch from DAMPs that initiate controlled tissue repair, to those that mediate chronic, uncontrolled inflammation is still unclear. Recent evidence suggests that an abnormal increase in protein citrullination is involved in disease pathophysiology (Anzilotti C et al. 2010; Sanchez-Pernaute O et al. 2013; Sokolove J et al. 2011; Sharma P et al. 2012). Citrullination is a post-translational modification event mediated by peptidyl-arginine deaminase enzymes which catalyze the deimination of proteins by converting arginine residues into citrullines in the presence of calcium ions."
BMGC_PW1440,BMG_PW4077,,,"MAPK6 and MAPK4 (also known as ERK3 and ERK4) are vertebrate-specific atypical MAP kinases. Atypical MAPK are less well characterized than their conventional counterparts, and are generally classified as such based on their lack of activation by MAPKK family members. Unlike the conventional MAPK proteins, which contain a Thr-X-Tyr motif in the activation loop, MAPK6 and 4 have a single Ser-Glu-Gly phospho-acceptor motif (reviewed in Coulombe and Meloche, 2007; Cargnello et al, 2011). MAPK6 is also distinct in being an unstable kinase, whose turnover is mediated by ubiquitin-dependent degradation (Coulombe et al, 2003; Coulombe et al, 2004). The biological functions and pathways governing MAPK6 and 4 are not well established. MAPK6 and 4 are phosphorylated downstream of class I p21 activated kinases (PAKs) in a RAC- or CDC42-dependent manner (Deleris et al, 2008; Perander et al, 2008; Deleris et al, 2011; De La Mota-Peynado et al, 2011). One of the only well established substrates of MAPK6 and 4 is MAPKAPK5, which contributes to cell motility by promoting the HSBP1-dependent rearrangement of F-actin (Gerits et al, 2007; Kostenko et al, 2009a; reviewed in Kostenko et al, 2011b). The atypical MAPKs also contribute to cell motility and invasiveness through the NCOA3:ETV4-dependent regulation of MMP gene expression (Long et al, 2012; Yan et al, 2008; Qin et al, 2008). Both of these pathways may be misregulated in human cancers (reviewed in Myant and Sansom, 2011; Kostenko et al, 2012)"
BMGC_PW1441,BMG_PW4079,,,The reactions annotated here describe genetic defects in genes regulating surfactant homeostasis which are associated with severe acute and chronic lung diseases in newborns and older infants (Whitsett et al. 2015).
BMGC_PW1442,BMG_PW4084,,,"Surfactant catabolism by alveolar macrophages plays a small but critical part in surfactant recycling and metabolism. Upon ligand binding, granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR), a heterodimer of alpha (CSF2RA) and beta (CSF2RB) subunits, initiates a signalling process that not only induces proliferation, differentiation and functional activation of hematopoietic cells but can also determine surfactant uptake into alveolar macrophages and its degradation via clathrin-coated vesicles. Defects in human CSF2RB can cause pulmonary surfactant metabolism dysfunction 5 (SMDP5; MIM:614370, aka pulmonary alveolar proteinosis 5, PAP5), a rare lung disorder due to impaired surfactant homeostasis characterised by alveoli filling with floccular material causing respiratory failure (Greenhill & Kotton 2009, Whitsett et al. 2015)."
BMGC_PW1443,BMG_PW4085,,,"Surfactant catabolism by alveolar macrophages plays a small but critical part in surfactant recycling and metabolism. Upon ligand binding, granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR), a heterodimer of alpha (CSF2RA) and beta (CSF2RB) subunits, initiates a signalling process that not only induces proliferation, differentiation and functional activation of hematopoietic cells but can also determine surfactant uptake into alveolar macrophages and its degradation via clathrin-coated vesicles. Defects in human CSF2RA can cause pulmonary surfactant metabolism dysfunction 4 (SMDP4; MIM:300770, aka congenital pulmonary alveolar proteinosis, (PAP)), a rare lung disorder due to impaired surfactant homeostasis characterised by alveoli filling with floccular material. Cellular responses to the misfolded pro-SFTPC products include ER stress, the activation of reactive oxygen species and autophagy. Excessive lipoprotein accumulation in the alveoli results in a form of respiratory distress syndrome in premature infants (RDS; MIM:267450) (Whitsett et al. 2015)."
BMGC_PW1444,BMG_PW4086,,,"DUBs of the Ub C-terminal Hydrolase (UCH) family are thiol proteases that have an N-terminal catalytic domain sometimes followed by C-terminal extensions that mediate protein-protein interactions. Humans have four UCH DUBs (UCH-L1, UCH-L3, UCH37/UCH-L5, and BAP1) that can be divided into the smaller UCH DUBs (UCH-L1 and UCH-L3), which cleave small leaving groups from the C-terminus of ubiquitin (Larsen et al. 1998), and the larger UCH DUBs (UCH37 and BAP1), which can disassemble poly-Ub chains (Misaghi et al. 2009, Lam et al. 1997)."
BMGC_PW1445,BMG_PW4087,,,"The Josephin domain is present in four human DUBs: Ataxin-3 (ATXN3), ATXN3L, Josephin-1 (JOSD1) and JOSD2. All have been shown to possess DUB activity (Tzveltkov & Breuer 2007, Weeks et al. 2011). Josephin domain DUBs may specialize in distinguishing between polyubiquitin chains of different lengths (Eletr & Wilkinson 2014)."
BMGC_PW1446,BMG_PW4088,,,"Ub-specific processing proteases (USPs) are the largest of the DUB families with more than 50 members in humans. The USP catalytic domain varies considerably in size and consists of six conserved motifs with N- or C-terminal extensions and insertions occurring between the conserved motifs (Ye et al. 2009). Two highly conserved regions comprise the catalytic triad, the Cys-box (Cys) and His-box (His and Asp/Asn) (Nijman et al. 2005, Ye et al. 2009, Reyes-Turcu & Wilkinson 2009). They recognize their substrates by interactions of the variable regions with the substrate protein directly, or via scaffolds or adapters in multiprotein complexes."
BMGC_PW1447,BMG_PW4089,,,"Humans have 16 Ovarian tumour domain (OTU) family DUBs that can be evolutionally divided into three classes, the OTUs, the Otubains (OTUBs), and the A20-like OTUs (Komander et al. 2009). OTU family DUBs can be highly selective in the type of ubiquitin crosslinks they cleave. OTUB1 is specific for K48-linked chains, whereas OTUB2 can cleave K11, K63 and K48-linked poly-Ub (Wang et al. 2009, Edelmann et al. 2009, Mevissen et al. 2013). A20 prefers K48-linked chains, Cezanne is specific for K11-linked chains, and TRABID acts on both K29, K33 and K63-linked poly-Ub (Licchesi et al. 2011, Komander & Barford 2008, Bremm et al. 2010, Mevissen et al. 2013). The active site of the OTU domain contains an unusual loop not seen in other thiol-DUBs and can lack an obvious catalytic Asp/Asn (Komander & Barford 2009, Messick et al. 2008, Lin et al. 2008). A20 and OTUB1 have an unusual mode of activity, binding directly to E2 enzymes (Nakada et al. 2010, Wertz et al. 2004)."
BMGC_PW1448,BMG_PW4090,,,"The JAB1/MPN +/MOV34 (JAMM) domain metalloproteases cleave the isopeptide bond at or near the the attachment point of polyubiquitin and substrate. PSMD14 (RPN11), STAMBP (AMSH), STAMBPL1 (AMSH-LP), and BRCC3 (BRCC36) are highly specific for the K63 poly-Ub linkage, which may be a general characteristic (Eletr & Wilkinson 2014). Two multisubunit complexes represented elsewhere in Reactome contain JAMM DUBs. The proteasome 19S lid complex includes PSMD14, an endopeptidase that cleaves poly-Ub chains from substrates as they are degraded by the proteasome (Verma et al. 2002). The COP9-Signalosome contains COPS5 (CSN5), which deconjugates the Ub-like modifier Nedd8, modulating the activity of the SCF E3 ligase (Cope et al. 2002). JAMM DUB catalysis requires nucleophilic attack on the carbonyl carbon of the isopeptide bond by an activated water molecule bound to Zn2+ and a conserved glutamate. A negatively-charged tetrahedral transition state ensues, and a nearby conserved Ser/Thr in the JAMM domains stabilizes the oxyanion. The tetrahedral intermediate then collapses and the Glu serves as a general base donating a proton to the leaving Lys side chain (Ambroggio et al. 2004)."
BMGC_PW1449,BMG_PW4092,,,"BCR activation is highly regulated and coreceptors like CD22 (SIGLEC2) set a signalling threshold to prevent aberrant immune response and autoimmune disease (Cyster et al. 1997, Han et al. 2005). CD22 is a glycoprotein found on the surface of B cells during restricted stages of development. CD22 is a member of the receptors of the sialic acid-binding Ig-like lectin (Siglec) family which binds specifically to the terminal sequence N-acetylneuraminic acid alpha(2-6) galactose (NeuAc-alpha(2-6)-Gal) present on many B-cell glycoproteins (Powell et al. 1993, Sgroi et al. 1993). CD22 has seven immunoglobulin (Ig)-like extracellular domains and a cytoplasmic tail containing six tyrosines, three of which belong to the inhibitory immunoreceptor tyrosine-based inhibition motifs (ITIMs) sequences. Upon BCR cross-linking CD22 is rapidly tyrosine phosphorylated by the tyrosine kinase Lyn, thereby recruiting and activating tyrosine phosphatase, SHP-1 and inhibiting calcium signalling."
BMGC_PW1450,BMG_PW4093,,,"Once repair synthesis has occurred, the D-loop structure may be resolved either through Holliday junction intermediates or through synthesis-dependent strand-annealing (SDSA) (Prado and Aguilera 2003, Ciccia and Elledge 2010)."
BMGC_PW1451,BMG_PW4094,,,"Detection of DNA double-strand breaks (DSBs) involves sensor proteins of the MRN complex, composed of MRE11A, RAD50 and NBN (NBS1). Binding of the MRN complex to DNA DSBs activates ATM-dependent DNA damage signaling cascade, by promoting KAT5 (Tip60) mediated acetylation of ATM and subsequent ATM autophosphorylation. Activated ATM triggers and coordinates recruitment of repair proteins to DNA DSBs (Beamish et al. 2002, Thompson and Schild 2002, Bakkenist et al. 2003, Lee and Paull 2005, Sun et al. 2005, Sun et al. 2007, Ciccia and Elledge 2010)."
BMGC_PW1452,BMG_PW4095,,,"In the synthesis-dependent strand-annealing (SDSA) model of D-loop resolution, D-loop strands extended by DNA repair synthesis dissociate from their sister chromatid complements and reanneal with their original complementary strands, resulting in non-crossover products (Mitchel et al. 2010). SDSA is promoted by the DNA helicase RTEL1 (Barber et al. 2008, Uringa et al. 2012). Additional DNA synthesis occurs to fill the remaining single strand gap present in the reannealed DNA duplex. DNA polymerase alpha has been implicated in this late step of DNA repair synthesis (Levy et al. 2009), although RTEL1-mediated recruitment of PCNA-bound DNA polymerases may also be involved (Vannier et al. 2013). The remaining single strand nicks are closed by DNA ligases, possibly LIG1 or LIG3 (Mortusewicz et al. 2006, Puebla-Osorio et al. 2006)."
BMGC_PW1453,BMG_PW4096,,,"Activated ATM phosphorylates a number of proteins involved in the DNA damage checkpoint and DNA repair (Thompson and Schild 2002, Ciccia and Elledge 2010), thereby triggering and coordinating accumulation of DNA DSB repair proteins in nuclear foci known as ionizing radiation-induced foci (IRIF). While IRIFs include chromatin regions kilobases away from the actual DSB site, this Reactome pathway represents simplified foci and events that happen proximal to the DNA DSB ends. In general, proteins localizing to the nuclear foci in response to ATM signaling are cooperatively retained at the DNA DSB site, forming a positive feedback loop and amplifying DNA damage response (Soutoglou and Misteli 2008). Activated ATM phosphorylates the NBN (NBS1) subunit of the MRN complex (MRE11A:RAD50:NBN) (Gatei et al. 2000), as well as the nucleosome histone H2AFX (H2AX) on serine residue S139, producing gamma-H2AFX (gamma-H2AX) containing nucleosomes (Rogakou et al. 1998, Burma et al. 2001). H2AFX is phosphorylated on tyrosine 142 (Y142) under basal conditions (Xiao et al. 2009). After ATM-mediated phosphorylation of H2AFX on S139, tyrosine Y142 has to be dephosphorylated by EYA family phosphatases in order for the DNA repair to proceed and to avoid apoptosis induced by DNA DSBs (Cook et al. 2009). Gamma-H2AFX recruits MDC1 to DNA DSBs (Stucki et al. 2005). After ATM phosphorylates MDC1 (Liu et al. 2012), the MRN complex, gamma-H2AFX nucleosomes, and MDC1 serve as a core of the nuclear focus and a platform for the recruitment of other proteins involved in DNA damage signaling and repair (Lukas et al. 2004, Soutoglou and Misteli 2008). RNF8 ubiquitin ligase binds phosphorylated MDC1 (Kolas et al. 2007) and, in cooperation with HERC2 and RNF168 (Bekker-Jensen et al. 2010, Campbell et al. 2012), ubiquitinates H2AFX (Mailand et al. 2007, Huen et al. 2007, Stewart et al. 2009, Doil et al. 2009) and histone demethylases KDM4A and KDM4B (Mallette et al. 2012). Ubiquitinated gamma-H2AFX recruits UIMC1 (RAP80), promoting the assembly of the BRCA1-A complex at DNA DSBs. The BRCA1-A complex consists of RAP80, FAM175A (Abraxas), BRCA1:BARD1 heterodimer, BRCC3 (BRCC36), BRE (BRCC45) and BABAM1 (MERIT40, NBA1) (Wang et al. 2007, Wang and Elledge 2007) Ubiquitin mediated degradation of KDM4A and KDM4B allows TP53BP1 (53BP1) to associate with histone H4 dimethylated on lysine K21 (H4K20Me2 mark) by WHSC1 at DNA DSB sites (Pei et al. 2011). Once recruited to DNA DSBs, both BRCA1:BARD1 heterodimers and TP53BP1 are phosphorylated by ATM (Cortez et al. 1999, Gatei et al. 2000, Kim et al. 2006, Jowsey et al. 2007), which triggers recruitment and activation of CHEK2 (Chk2, Cds1) (Wang et al. 2002, Wilson and Stern 2008, Melchionna et al. 2000). Depending on the cell cycle stage, BRCA1 and TP53BP1 competitively promote either homology directed repair (HDR) or nonhomologous end joining (NHEJ) of DNA DSBs. HDR through homologous recombination repair (HRR) or single strand annealing (SSA) is promoted by BRCA1 in association with RBBP8 (CtIP), while NHEJ is promoted by TP53BP1 in association with RIF1 (Escribano-Diaz et al. 2013)."
BMGC_PW1454,BMG_PW4097,,,
BMGC_PW1455,BMG_PW4098,,,"D-loops generated after strand invasion and DNA repair synthesis during homologous recombination repair (HRR) can be resolved through Holliday junction intermediates. A D-loop can be cleaved by the complex of MUS81 and EME1 (MUS81:EME1) or MUS81 and EME2 (MUS81:EME2) and resolved without the formation of double Holliday junctions, generating cross-over products. All steps involved in this process have not been elucidated (Osman et al. 2003, Schwartz et al. 2012, Pepe and West 2014). Alternatively, double Holliday junctions can be created by ligation of crossed-strand intermediates. Double Holliday junctions can then be resolved through the action of the BLM helicase complex known as BTRR (BLM:TOP3A:RMI1:RMI2) (Wan et al. 2013, Bocquet et al. 2014). BLM-mediated resolution of Holliday junction intermediates prevents sister chromatid exchange (SCE) between mitotic chromosomes and generates non-crossover products. SPIDR enables recruitment of the BTTR complex to the ionizing radiation-induced foci. The complex of FIGNL1 and FIRRM, which, through FIGNL1, simultaneously interacts with SPIDR (Yuan and Chen 2013) and RAD51 (Yuan and Chen 2013, Fernandes et al. 2018), may facilitate the function of SPIDR in promoting the no cross-over route of homologous recombination repair. Mitotic SCE can result in the loss-of-heterozygosity (LOH), which can make the cell homozygous for deleterious recessive mutations (e.g. in tumor suppressor genes) (Wu and Hickson 2003). Double Holliday junctions can also be resolved by cleavage, mediated by GEN1 or the SLX-MUS complex (composed of SLX1A:SLX4 heterodimer and a heterodimer of MUS81 and EME1 or, possibly, EME2). The resolvase activity of GEN1 and SLX-MUS predominantly results in crossover products, with SCE (Fekairi et al. 2009, Wyatt et al. 2013, Sarbajna et al. 2014)."
BMGC_PW1456,BMG_PW4099,,,"The presynaptic phase of homologous DNA pairing and strand exchange begins with the displacement of RPA from 3'-ssDNA overhangs created by extensive resection of DNA double-strand break (DSB) ends. RPA is displaced by the joint action of RAD51 and BRCA2. BRCA2 nucleates RAD51 on 3'-ssDNA overhangs, leading to formation of invasive RAD51 nucleofilaments which are stabilized by the BCDX2 complex (RAD51B:RAD51C:RAD51D:XRCC2). Stable synaptic pairing between recombining DNA molecules involves the invasion of the homologous sister chromatid duplex DNA by the RAD51 nucleofilament and base-pairing between the invading ssDNA and the complementary sister chromatid DNA strand, while the non-complementary strand of the sister chromatid DNA duplex is displaced. This results in the formation of a D-loop structure (Sung et al., 2003). PALB2 and RAD51AP1 synergistically stimulate RAD51 recombinase activity and D-loop formation. PALB2 simultaneously interacts with RAD51, BRCA2 and RAD51AP1 (Modesti et al. 2007, Wiese et al. 2007, Buisson et al. 2010, Dray et al. 2010). PALB2 also interacts with BRCA1, and this interaction fine-tunes the localization of BRCA2 and RAD51 at DNA DSBs (Zhang et al. 2009, Sy et al. 2009). The CX3 complex, composed of RAD51C and XRCC3, binds D-loop structures through interaction with PALB2 and may be involved in the resolution of Holliday junctions (Chun et al. 2013, Park et al. 2014). While RAD52 promotes formation of invasive RAD51 nucleofilaments in yeast, human BRCA2 performs this function, while human RAD52 regulates single strand annealing (SSA) (reviewed by Ciccia and Elledge 2010)."
BMGC_PW1457,BMG_PW4100,,,"DNA double-strand break (DSB) response involves sensing of DNA DSBs by the MRN complex which triggers ATM activation. ATM phosphorylates a number of proteins involved in DNA damage checkpoint signaling, as well as proteins directly involved in the repair of DNA DSBs. For a recent review, please refer to Ciccia and Elledge, 2010."
BMGC_PW1458,BMG_PW4101,,,"Homology directed repair (HDR) through homologous recombination (HRR) or single strand annealing (SSA) requires extensive resection of DNA double-strand break (DSB) ends (Thompson and Limoli 2003, Ciccia and Elledge 2010). The resection is performed in a two-step process, where the MRN complex (MRE11A:RAD50:NBN) and RBBP8 (CtIP) bound to BRCA1 initiate the resection. This step is regulated by the complex of CDK2 and CCNA (cyclin A), ensuring the initiation of HRR during S and G2 phases of the cell cycle, when sister chromatids are available. The initial resection is also regulated by ATM-mediated phosphorylation of RBBP8 and CHEK2-mediated phosphorylation of BRCA1 (Chen et al. 2008, Yun and Hiom 2009, Buis et al. 2012, Wang et al. 2013, Davies et al. 2015, Parameswaran et al. 2015). After the initial resection, DNA nucleases EXO1 and/or DNA2 perform long-range resection, which is facilitated by DNA helicases BLM or WRN, as well as BRIP1 (BACH1) (Chen et al. 2008, Nimonkar et al. 2011, Sturzenegger et al. 2014, Suhasini et al. 2011). The resulting long 3'-ssDNA overhangs are coated by the RPA heterotrimers (RPA1:RPA2:RPA3), which recruit ATR:ATRIP complexes to DNA DSBs and, in collaboration with RAD17:RFC and RAD9:HUS1:RAD1 complexes, and TOPBP1 and RHNO1, activate ATR signaling. Activated ATR phosphorylates RPA2 and activates CHEK1 (Cotta-Ramusino et al. 2011), both of which are necessary prerequisites for the subsequent steps in HRR and SSA."
BMGC_PW1459,BMG_PW4102,,,"The presynaptic phase of homologous DNA pairing and strand exchange during homologous recombination repair (HRR) begins with the displacement of RPA from ssDNA (Thompson and Limoli 2003) by the joint action of RAD51 and BRCA2. CHEK1-mediated phosphorylation of RAD51 and BRCA2 (Sorensen et al. 2005, Bahassi et al. 2008) is needed for BRCA2-mediated nucleation of RAD51 on 3'-ssDNA overhangs, RPA displacement and formation of RAD51 nucleofilaments (Yang et al. 2005, Jensen et al. 2010, Liu et al. 2010, Thorslund et al. 2010). Invasive RAD51 nucleofilaments are stabilized by the BCDX2 complex composed of RAD51B, RAD51C, RAD51D and XRCC2 (Masson et al. 2001, Chun et al. 2013, Amunugama et al. 2013)."
BMGC_PW1460,BMG_PW4103,,,"Computational analysis suggests that ~25% of the proteome may be exported from the ER in human cells (Kanapin et al, 2003). These cargo need to be recognized and concentrated into COPII vesicles, which range in size from 60-90 nm, and which move cargo from the ER to the ERGIC in mammalian cells (reviewed in Lord et al, 2013; Szul and Sztul, 2011). Recognition of transmembrane cargo is mediated by interaction with one of the 4 isoforms of SEC24, a component of the inner COPII coat (Miller et al, 2002; Miller et al, 2003; Mossessova et al, 2003; Mancias and Goldberg, 2008). Soluble cargo in the ER lumen is concentrated into COPII vesicles through interaction with a receptor of the ERGIC-53 family, the p24 family or the ERV family. Each of these families of transmembrane receptors interact with cargo through their lumenal domains and with components of the COPII coat with their cytoplasmic domains and are packaged into the COPII vesicle along with the cargo. The receptors are subsequently recycled to the ER in COPI vesicles through retrograde traffic (reviewed in Dancourt and Barlowe, 2010). Packaging of large cargo such as fibrillar collagen depends on the transmembrane accessory factors MIA3 (also known as TANGO1) and CTAGE5. Like the ERGIC, p24 and ERV cargo receptors, MIA3 and MIA2 (also known as CTAGE5) interact both with the collagen cargo and with components of the COPII coat. Unlike the other cargo receptors, however, MIA3 and MIA2 are not loaded into the vesicle but remain in the ER membrane (reviewed in Malhotra and Erlmann, 2011; Malhotra et al, 2015)."
BMGC_PW1461,BMG_PW4104,,,"In global genome nucleotide excision repair (GG-NER), the DNA damage is recognized by two protein complexes. The first complex consists of XPC, RAD23A or RAD23B, and CETN2. This complex probes the DNA helix and recognizes damage that disrupts normal Watson-Crick base pairing, which results in binding of the XPC:RAD23:CETN2 complex to the undamaged DNA strand. The second complex is a ubiquitin ligase UV-DDB that consists of DDB2, DDB1, CUL4A or CUL4B and RBX1. The UV-DDB complex is necessary for the recognition of UV-induced DNA damage and may contribute to the retention of the XPC:RAD23:CETN2 complex at the DNA damage site. The UV-DDB complex binds the damaged DNA strand (Fitch et al. 2003, Wang et al. 2004, Moser et al. 2005, Camenisch et al. 2009, Oh et al. 2011)."
BMGC_PW1462,BMG_PW4105,,,"After the XPC complex and the UV-DDB complex bind damaged DNA, a basal transcription factor TFIIH is recruited to the nucleotide excision repair (NER) site (Volker et al. 2001, Riedl et al. 2003). DNA helicases ERCC2 (XPD) and ERCC3 (XPB) are subunits of the TFIIH complex. ERCC2 unwinds the DNA around the damage in concert with the ATPase activity of ERCC3, creating an open bubble (Coin et al. 2007). Simultaneously, the presence of the damage is verified by XPA (Camenisch et al. 2006). The recruitment of XPA is partially regulated by PARP1 and/or PARP2 (King et al. 2012). Two DNA endonucleases, ERCC5 (XPG) and the complex of ERCC1 and ERCC4 (XPF), are recruited to the open bubble structure to form the incision complex that will excise the damaged oligonucleotide from the affected DNA strand (Dunand-Sauthier et al. 2005, Zotter et al. 2006, Riedl et al. 2003, Tsodikov et al. 2007, Orelli et al. 2010). The RPA heterotrimer coats the undamaged DNA strand, thus protecting it from the endonucleolytic attack (De Laat et al. 1998)."
BMGC_PW1463,BMG_PW4106,,,"Global genome nucleotide excision repair (GG-NER) is completed by DNA repair synthesis that fills the single stranded gap created after dual incision of the damaged DNA strand and excision of the ~27-30 bases long oligonucleotide that contains the lesion. DNA synthesis is performed by DNA polymerases epsilon or delta, or the Y family DNA polymerase kappa (POLK), which are loaded to the repair site after 5' incision (Staresincic et al. 2009, Ogi et al. 2010). DNA ligases LIG1 or LIG3 ligate the newly synthesized stretch of oligonucleotides to the incised DNA strand (Arakawa et al. 2012, Paul-Konietzko et al. 2015)."
BMGC_PW1464,BMG_PW4107,,,"The DNA damage in GG-NER is recognized by the joint action of two protein complexes. The first complex is composed of XPC, RAD23A or RAD23B and CETN2. The second complex, known as the UV-DDB complex, is an ubiquitin ligase composed of DDB1, CUL4A or CUL4B, RBX1 and a GG-NER specific protein DDB2. In vitro, the UV-DDB complex is onlynecessary for GG-NER mediated repair of UV-induced pyrimidine dimers. In vivo, however, where DNA repair occurs in the chromatin context, the UV-DDB complex likely facilitates GG-NER mediated repair irrespective of the DNA damage type. After DNA damage recognition, the TFIIH complex, together with XPA, verifies the DNA damage and unwinds the DNA helix around the damage, creating an open bubble. Two DNA endonucleases, ERCC5 (XPG) and the complex of ERCC1 and ERCC4 (XPF), excise the oligonucleotide that contains damaged base(s) from the affected DNA strand. DNA polymerases delta, epsilon and/or kappa perform DNA repair synthesis, followed by DNA ligation, thus completing GG-NER. For a recent review, please refer to Marteijn et al. 2014."
BMGC_PW1465,BMG_PW4108,,,"Double incision at the damaged DNA strand excises the oligonucleotide that contains the lesion from the open bubble. The excised oligonucleotide is ~27-30 bases long. Incision 5' to the damage site, by ERCC1:ERCC4 endonuclease, precedes the incision 3' to the damage site by ERCC5 endonuclease (Staresincic et al. 2009)."
BMGC_PW1466,BMG_PW4109,,,"After translation, many newly formed proteins undergo further covalent modifications that alter their functional properties. Modifications associated with protein localization include the attachment of oligosaccharide moieties to membrane-bound and secreted proteins (N-linked and O-linked glycosylation), the attachment of lipid (RAB geranylgeranylation) or glycolipid moieties (GPI-anchored proteins) that anchor proteins to cellular membranes, and the vitamin K-dependent attachment of carboxyl groups to glutamate residues. Modifications associated with functions of specific proteins include gamma carboxylation of clotting factors, hypusine formation on eukaryotic translation initiation factor 5A, conversion of a cysteine residue to formylglycine (arylsulfatase activation), methylation of lysine and arginine residues on non-histone proteins (protein methylation), protein phosphorylation by secretory pathway kinases, and carboxyterminal modifications of tubulin involving the addition of polyglutamate chains. Protein ubiquitination and deubiquitination play a major role in regulating protein stability and, together with SUMOylation and neddylation, can modulate protein function as well."
BMGC_PW1467,BMG_PW4110,,,"Eukaryotic centromeres are marked by a unique form of histone H3, designated CENPA in humans. In human cells newly synthesized CENPA is deposited in nucleosomes at the centromere during late telophase/early G1 phase of the cell cycle. Once deposited, nucleosomes containing CENPA remain stably associated with the centromere and are partitioned equally to daughter centromeres during S phase. A current model proposes that pre-existing CENPA at the centromere drives recruitment of new CENPA, however this has not been proved. The deposition process requires at least 3 complexes: the Mis18 complex, HJURP complex, and the RSF complex. HJURP binds newly synthesized CENPA-H4 tetramers before deposition and brings them to the centromere for deposition in new CENPA-containing nucleosomes. The exact mechanism of deposition remains unknown."
BMGC_PW1468,BMG_PW4111,,,"In contrast to NOD1/2 some NLRPs function as large macromolecular complexes called 'Inflammasomes'. These multiprotein platforms control activation of the cysteinyl aspartate protease caspase-1 and thereby the subsequent cleavage of pro-interleukin 1B (pro-IL1B) into the active proinflammatory cytokine IL1B. Activation of caspase-1 is essential for production of IL1B and IL18, which respectively bind and activate the IL1 receptor (IL1R) and IL18 receptor (IL18R) complexes. IL1R and IL18R activate NFkappaB and other signaling cascades. As the activation of inflammasomes leads to caspase-1 activation, inflammasomes can be considered an upstream step of the IL1R and IL18R signaling cascades, linking intracellular pathogen sensing to immune response pathways mediated by Toll-Like Receptors (TLRs). Monocytes and macrophages do not express pro-IL1B until stimulated, typically by TLRs (Franchi et al. 2009). The resulting pro-IL1B is not converted to IL1B unless a second stimulus activates an inflammasome. This requirement for two distinct stimuli allows tight regulation of IL1B/IL18 production, necessary because excessive IL-1B production is associated with numerous inflammatory diseases such as gout and rheumatoid arthritis (Masters et al. 2009). There are at least four subtypes of the inflammasome, characterized by the NLRP. In addition the protein AIM2 can form an inflammasome. All activate caspase-1. NLRP1 (NALP1), NLRP3 (Cryopyrin, NALP3), IPAF (CARD12, NLRC4) and AIM2 inflammasomes all have clear physiological roles in vivo. NLRP2, NLRP6, NLRP7, NLRP10 and NLRP12 have been demonstrated to modulate caspase-1 activity in vitro but the significance of this is unclear (Mariathasan and Monack, 2007). NLRP3 and AIM2 bind the protein 'apoptosis-associated speck-like protein containing a CARD' (ASC, also called PYCARD), via a PYD-PYD domain interaction. This in turn recruits procaspase-1 through a CARD-CARD interaction. NLRP1 and IPAF contain CARD domains and can bind procaspase-1 directly, though both are stimulated by ASC. Oligomerization of NLRPs is believed to bring procaspases into close proximity, leading to 'induced proximity' auto-activation (Boatright et al. 2003). This leads to formation of the active caspase tetramer. NLRPs are generally considered to be cytoplasmic proteins, but there is evidence for cytoplasmic-nuclear shuttling of the family member CIITA (LeibundGut-Landmann et al. 2004) and tissue/cell dependent NALP1 expression in the nucleus of neurons and lymphocytes (Kummer et al. 2007); the significance of this remains unclear."
BMGC_PW1469,BMG_PW4112,,,"Presynaptic acetylcholine receptors are located at or near nerve terminal and modulate the release of neurotransmitter such as glutamate, noradrenaline and dopamine. Activation of presynaptic acetylcholine receptors leads to influx of Ca2+ and sufficient increase in local Ca2+ concentrations which could be due to either direct or indirect Ca2+ entry. Direct Ca2+ entry through acetylcholine receptors containing alpha3 beta4 receptors is sufficient for the release of noradrenaline in hippocampus. Indirect Ca2+ increase could be due to Na+ dependent depolarization and activation of voltage dependent calcium channels (VDCC) as in the case of dopamine release. Local Ca2+ increase could also be due to an initial Ca2+ influx through acetlycholine homomeric receptors containing alpha7 subunits and further increase in Ca2+ is elicited due to Ca2+ induced Ca2+ release (CICR) that involves the ryanodine receptors in the ER and the IP3 receptors. This mechanism is used in hippocampal mossy fibre pathway. Nicotinic acetylcholine receptors may permit both sodium and calcium ions, however, the ratio of sodium and calcium influx makes these receptors either highly sodium permeable or highly calcium permeable."
BMGC_PW1470,BMG_PW4113,,,"Nicotinic acetylcholine receptors are found in the postsynaptic terminals and these receptors are responsible in mediating postsynaptic currents. Most common types of neuronal postsynaptic nicotinic acetylcholine receptors are homomeric alpha 7 containing acetylcholine receptors. The densities of acetylcholine receptors are found to be similar to NMDA and AMPA receptors at these sites. Nicotinic acetylcholine receptors may permit both sodium and calcium ions, however, the ratio of sodium and calcium influx makes the receptors either highly sodium permeable or highly calcium permeable."
BMGC_PW1471,BMG_PW4114,,,Nicotinic acetylcholne receptors that have low Ca2+ permeability allow the influx of Na+ which causes depolarization of the membrane initiating voltage dependent responses such as activation of voltage dependent opening of Ca2+ channels and thus eliciting an increase in Ca2+ and downstream signaling. These receptors could be found in both presynaptic and postsynaptic terminals.
BMGC_PW1472,BMG_PW4115,,,Postsynaptic acetylcholine receptors mediate Ca2+ currents that may be involved in the facilitation of long term potentiation (LTP).
BMGC_PW1473,BMG_PW4116,,,"Nicotinic acetylcholine receptors exhibit high influx of Ca2+, the degree of Ca2+ permeability is dependent on the subunit composition; homomeric acetylcholine receptors containing aplha 7 subunits allow maximum Ca2+ influx followed by receptors containing alpha3 beta2 alpha5 or alpha3 beta4 alpha5."
BMGC_PW1474,BMG_PW4117,,,"For initiation, Pol II assembles with the general transcription factors TFIIB, TFIID, TFIIE, TFIIF and TFIIH, which are collectively known as the general transcription factors, at promoter DNA to form the pre-initiation complex (PIC). Until the nascent transcript is about 15 nucleotides long, the early transcribing complex is functionally unstable. In the beginning, short RNAs are frequently released and Pol II has to restart transcription (abortive cycling). There is a decline in the level of abortive transcription when the RNA reaches a length of about four nucleotides, and this transition is termed escape commitment"
BMGC_PW1475,BMG_PW4118,,,"Formation of TC-NER pre-incision complex is initiated when the RNA polymerase II (RNA Pol II) complex stalls at a DNA damage site. The stalling is caused by misincorporation of a ribonucleotide opposite to a damaged base (Brueckner et al. 2007). Cockayne syndrome protein B (ERCC6, CSB) binds stalled RNA Pol II and recruits Cockayne syndrome protein A (ERCC8, CSA). ERCC8 is part of an ubiquitin ligase complex that also contains DDB1, CUL4A or CUL4B and RBX1. This complex is implicated in the regulation of TC-NER progression probably by ubiquitinating one or more factors involved in this pathway, which may include RNA Pol II and ERCC6 at the later stages of repair (Bregman et al. 1996, Fousteri et al. 2006, Groisman et al. 2006). XPA is recruited to the TC-NER site through its interaction with the TFIIH complex (Furuta et al. 2002, Ziani et al. 2014). The XAB2 complex, which probably regulates the accessibility of the DNA damage site through its RNA-DNA helicase activity, binds the TC-NER site via the interaction of its XAB2 subunit with RNA Pol II, ERCC6, ERCC8 and XPA (Nakatsu et al. 2000, Sollier et al. 2014). TCEA1 (TFIIS) is a transcription elongation factor that may facilitate backtracking of the stalled RNA Pol II, enabling access of repair proteins to the DNA damage site and promotes partial digestion of the 3' protruding end of the nascent mRNA transcript by the backtracked RNA Pol II, allowing resumption of RNA synthesis after damage removal (Donahue et al. 1994). Access to DNA damage sites in TC-NER was suggested to be facilitated by a chromatin remodeler HMGN1 (Birger et al. 2003), but another sudy found that HMGN1 was not needed for human TC-NER (Apelt et al. 2020). UVSSA protein interacts with ubiquitinated ERCC6 and RNA Pol II, recruiting ubiquitin protease USP7 to the TC-NER site and promoting ERCC6 stabilization (Nakazawa et al. 2012, Schwertman et al. 2012, Zhang et al. 2012, Fei and Chen 2012)."
BMGC_PW1476,BMG_PW4119,,,"DNA damage in transcribed strands of active genes is repaired through a specialized nucleotide excision repair (NER) pathway known as transcription-coupled nucleotide excision repair (TC-NER). TC-NER impairment is the underlying cause of a severe hereditary disorder Cockayne syndrome, an autosomal recessive disease characterized by hypersensitivity to UV light. TC-NER is triggered by helix distorting lesions that block the progression of elongating RNA polymerase II (RNA Pol II). Stalled RNA Pol II complex triggers the recruitment of ERCC6. ERCC6, commonly known as CSB (Cockayne syndrome protein B) recruits ERCC8, commonly known as CSA (Cockayne syndrome protein A). ERCC8 has 7 WD repeat motifs and is part of the ubiquitin ligase complex that also includes DDB1, CUL4A or CUL4B and RBX1. The ERCC8 ubiquitin ligase complex is one of the key regulators of TC-NER that probably exerts its role by ubiquitinating one or more factors involved in this repair process, including the RNA Pol II complex and ERCC6. In addition to RNA Pol II, ERCC6 and the ERCC8 complex, the transcription elongation factor TFIIH, which is also involved in global genome nucleotide excision repair (GG-NER), is recruited to sites of TC-NER. The TC-NER pre-incision complex also includes XPA, XAB2 complex, TCEA1 (TFIIS), HMGN1, UVSSA in complex with USP7, and EP300 (p300). XPA probably contributes to the assembly and stability of the pre-incision complex, similar to its role in GG-NER. The XAB2 complex is involved in pre-mRNA splicing and may modulate the structure of the nascent mRNA hybrid with template DNA through its RNA-DNA helicase activity, allowing proper processing of DNA damage. TCEA1 may be involved in RNA Pol II backtracking, which allows repair proteins to gain access to the damage site. It also facilitates trimming of the 3' end of protruding nascent mRNA from the stalled RNA Pol II, enabling recovery of RNA synthesis after repair. Deubiquitinating activity of the UVSSA:USP7 complex is needed for ERCC6 stability at repair sites. Non-histone nucleosomal binding protein HMGN1 and histone acetyltransferase p300 (EP300) remodel the chromatin around the damaged site, thus facilitating repair. Dual incision of the lesion-containing oligonucleotide from the affected DNA strand is performed by two DNA endonucleases, the ERCC1:ERCC4 (ERCC1:XPF) complex and ERCC5 (XPG), which also participate in GG-NER. DNA polymerases delta, epsilon or kappa fill in the single stranded gap after dual incision and the remaining single strand nick is sealed by DNA ligases LIG1 or LIG3 (the latter in complex with XRCC1), similar to GG-NER. After the repair of DNA damage is complete, RNA Pol II resumes RNA synthesis. For past and recent reviews, see Mellon et al. 1987, Svejstrup 2002, Hanawalt and Spivak 2008, Vermeulen and Fousteri 2013 and Marteijn et al. 2014."
BMGC_PW1477,BMG_PW4120,,,"In transcription-coupled nucleotide excision repair (TC-NER), similar to global genome nucleotide excision repair (GG-NER), the oligonucleotide that contains the lesion is excised from the open bubble structure via dual incision of the affected DNA strand. 5' incision by the ERCC1:ERCC4 (ERCC1:XPF) endonuclease precedes 3' incision by ERCC5 (XPG) endonuclease. In order for the TC-NER pre-incision complex to assemble and the endonucleases to incise the damaged DNA strand, the RNA polymerase II (RNA Pol II) complex has to backtrack - reverse translocate from the damage site. Although the mechanistic details of this process are largely unknown in mammals, it may involve ERCC6/ERCC8-mediated chromatin remodelling/ubiquitination events, the DNA helicase activity of the TFIIH complex and TCEA1 (TFIIS)-stimulated cleavage of the 3' protruding end of nascent mRNA by RNA Pol II (Donahue et al. 1994, Lee et al. 2002, Sarker et al. 2005, Vermeulen and Fousteri 2013, Hanawalt and Spivak 2008, Staresincic et al. 2009, Epshtein et al. 2014)."
BMGC_PW1478,BMG_PW4121,,,"In transcription-coupled nucleotide excision repair (TC-NER), similar to global genome nucleotide excision repair (GG-NER), DNA polymerases delta or epsilon, or the Y family DNA polymerase kappa, fill in the single stranded gap that remains after dual incision. DNA ligases LIG1 or LIG3, subsequently seal the single stranded nick by ligating the 3' end of the newly synthesized patch with the 5' end of incised DNA (Staresincic et al. 2009, Ogi et al. 2010, Arakawa et al. 2012, Paul-Konietzko et al. 2015)."
BMGC_PW1479,BMG_PW4122,,,"At least 92 distinct tRNA nucleotide base modifications have been found. The modifications are made post-transcriptionally by a large group of disparate enzymes located in the nucleus, cytosol, and mitochondria (reviewed in Boschi-Muller and Motorin 2013, Jackman and Alfonzo 2013, Gu et al. 2014, Helm and Alfonzo 2014, Li and Mason 2014). Modifications near the anticodon and near the 3' end affect interaction of the tRNA with ribosomes and tRNA synthetases, respectively, while modifications in other regions of the tRNA affect folding and stability of the tRNA (reviewed in Hou et al. 2015). Mutations in tRNA modification enzymes are associated with human diseases (reviewed in Sarin and Leidel 2014, Torres et al. 2014)."
BMGC_PW1480,BMG_PW4124,,,"Genes encoding transfer RNAs are transcribed in the nucleus by RNA polymerase III. (Distinct processes of transcription and processing also occur in mitochondria.) The initial transcripts, pre-tRNAs, contain extra nucleotides at the 5' end and 3' end. 6.3% (32 of 509) of human tRNAs also contain introns, which are located in the anticodon loop, 3' to the anticodon. The additional nucleotides are removed and a non-templated CCA sequence is added to the resulting 3' terminus by processing reactions in the nucleus and cytosol (reviewed in Nakanishi and Nureki 2005, Phizicky and Hopper 2010). The order of processing and nucleotide modification events may be different for different tRNAs and its analysis is complicated by a retrograde transport mechanism that can import tRNAs from the cytosol back to the nucleus (retrograde movement, Shaheen and Hopper 2005, reviewed in Phizicky 2005). Generally, the 5' leader of the pre-tRNA is removed first by endonucleolytic cleavage by the RNase P ribonucleoprotein complex, which contains a catalytic RNA (RNA H1 in humans) and at least 10 protein subunits (reviewed in Jarrous 2002, Xiao et al. 2002, Jarrous and Gopalan 2010). The 3' trailer is then removed by RNase Z activity, a single protein in humans (reviewed in Maraia and Lamichhane 2011). ELAC2 is a RNase Z found in both nucleus and mitochondria. ELAC1 is found in the cytosol and may also act as an RNase Z. Human tRNA genes do not encode the universal acceptor 3' terminus CCA, instead it is added post-transcriptionally by TRNT1, an unusual polymerase that requires no nucleic acid template (reviewed in Xiong and Steitz 2006, Hou 2010, Tomita and Yamashita 2014). In humans introns are spliced from intron-containing tRNAs in the nucleus by a two step mechanism that is distinct from mRNA splicing (reviewed in Popow et al. 2012, Lopes et al. 2015). The TSEN complex first cleaves 5' and 3' to the intron, generating a 2'3' cyclic phosphate on the 5' exon and a 5' hydroxyl group on the 3' exon. These two ends are ligated by a complex containing at least 6 proteins in a single reaction that both hydrolyzes the 2' phosphate bond and joins the 3' phosphate to the 5' hydroxyl. (In yeast the ligation and the hydrolysis of the 2' phosphate are separate reactions. The splicing reactions in yeast occur in the cytosol at the mitochondrial outer membrane.) Mature transfer RNAs contain a large number of modified nucleotide residues that are produced by post-transcriptional modification reactions (reviewed in Li and Mason 2014). Depending on the specific tRNA these reactions may occur before or after splicing and before or after export from the nucleus to the cytosol."
BMGC_PW1481,BMG_PW4126,,,"Activated ERBB2 heterodimers regulate cell motility through association with MEMO1. MEMO1 retains activated RHOA GTPase and its associated protein DIAPH1 at the plasma membrane, thus linking ERBB2 activation with the microtubule and actin dynamics downstream of the RHOA:GTP:DIAPH1 complex (Marone et al. 2004, Qiu et al. 2008, Zaoui et al. 2008, Zaoui et al. 2010)."
BMGC_PW1482,BMG_PW4127,,,"Interleukin-4 (IL4) is a principal regulatory cytokine during the immune response, crucially important in allergy and asthma (Nelms et al. 1999). When resting T cells are antigen-activated and expand in response to Interleukin-2 (IL2), they can differentiate as Type 1 (Th1) or Type 2 (Th2) T helper cells. The outcome is influenced by IL4. Th2 cells secrete IL4, which both stimulates Th2 in an autocrine fashion and acts as a potent B cell growth factor to promote humoral immunity (Nelms et al. 1999). Interleukin-13 (IL13) is an immunoregulatory cytokine secreted predominantly by activated Th2 cells. It is a key mediator in the pathogenesis of allergic inflammation. IL13 shares many functional properties with IL4, stemming from the fact that they share a common receptor subunit. IL13 receptors are expressed on human B cells, basophils, eosinophils, mast cells, endothelial cells, fibroblasts, monocytes, macrophages, respiratory epithelial cells, and smooth muscle cells, but unlike IL4, not T cells. Thus IL13 does not appear to be important in the initial differentiation of CD4 T cells into Th2 cells, rather it is important in the effector phase of allergic inflammation (Hershey et al. 2003). IL4 and IL13 induce “alternative activation” of macrophages, inducing an anti-inflammatory phenotype by signaling through IL4R alpha in a STAT6 dependent manner. This signaling plays an important role in the Th2 response, mediating anti-parasitic effects and aiding wound healing (Gordon & Martinez 2010, Loke et al. 2002) There are two types of IL4 receptor complex (Andrews et al. 2006). Type I IL4R (IL4R1) is predominantly expressed on the surface of hematopoietic cells and consists of IL4R and IL2RG, the common gamma chain. Type II IL4R (IL4R2) is predominantly expressed on the surface of nonhematopoietic cells, it consists of IL4R and IL13RA1 and is also the type II receptor for IL13. (Obiri et al. 1995, Aman et al. 1996, Hilton et al. 1996, Miloux et al. 1997, Zhang et al. 1997). The second receptor for IL13 consists of IL4R and Interleukin-13 receptor alpha 2 (IL13RA2), sometimes called Interleukin-13 binding protein (IL13BP). It has a high affinity receptor for IL13 (Kd = 250 pmol/L) but is not sufficient to render cells responsive to IL13, even in the presence of IL4R (Donaldson et al. 1998). It is reported to exist in soluble form (Zhang et al. 1997) and when overexpressed reduces JAK-STAT signaling (Kawakami et al. 2001). It's function may be to prevent IL13 signalling via the functional IL4R:IL13RA1 receptor. IL13RA2 is overexpressed and enhances cell invasion in some human cancers (Joshi & Puri 2012). The first step in the formation of IL4R1 (IL4:IL4R:IL2RB) is the binding of IL4 with IL4R (Hoffman et al. 1995, Shen et al. 1996, Hage et al. 1999). This is also the first step in formation of IL4R2 (IL4:IL4R:IL13RA1). After the initial binding of IL4 and IL4R, IL2RB binds (LaPorte et al. 2008), to form IL4R1. Alternatively, IL13RA1 binds, forming IL4R2. In contrast, the type II IL13 complex (IL13R2) forms with IL13 first binding to IL13RA1 followed by recruitment of IL4R (Wang et al. 2009). Crystal structures of the IL4:IL4R:IL2RG, IL4:IL4R:IL13RA1 and IL13:IL4R:IL13RA1 complexes have been determined (LaPorte et al. 2008). Consistent with these structures, in monocytes IL4R is tyrosine phosphorylated in response to both IL4 and IL13 (Roy et al. 2002, Gordon & Martinez 2010) while IL13RA1 phosphorylation is induced only by IL13 (Roy et al. 2002, LaPorte et al. 2008) and IL2RG phosphorylation is induced only by IL4 (Roy et al. 2002). Both IL4 receptor complexes signal through Jak/STAT cascades. IL4R is constitutively-associated with JAK2 (Roy et al. 2002) and associates with JAK1 following binding of IL4 (Yin et al. 1994) or IL13 (Roy et al. 2002). IL2RG constitutively associates with JAK3 (Boussiotis et al. 1994, Russell et al. 1994). IL13RA1 constitutively associates with TYK2 (Umeshita-Suyama et al. 2000, Roy et al. 2002, LaPorte et al. 2008, Bhattacharjee et al. 2013). IL4 binding to IL4R1 leads to phosphorylation of JAK1 (but not JAK2) and STAT6 activation (Takeda et al. 1994, Ratthe et al. 2007, Bhattacharjee et al. 2013). IL13 binding increases activating tyrosine-99 phosphorylation of IL13RA1 but not that of IL2RG. IL4 binding to IL2RG leads to its tyrosine phosphorylation (Roy et al. 2002). IL13 binding to IL4R2 leads to TYK2 and JAK2 (but not JAK1) phosphorylation (Roy & Cathcart 1998, Roy et al. 2002). Phosphorylated TYK2 binds and phosphorylates STAT6 and possibly STAT1 (Bhattacharjee et al. 2013). A second mechanism of signal transduction activated by IL4 and IL13 leads to the insulin receptor substrate (IRS) family (Kelly-Welch et al. 2003). IL4R1 associates with insulin receptor substrate 2 and activates the PI3K/Akt and Ras/MEK/Erk pathways involved in cell proliferation, survival and translational control. IL4R2 does not associate with insulin receptor substrate 2 and consequently the PI3K/Akt and Ras/MEK/Erk pathways are not activated (Busch-Dienstfertig & González-Rodríguez 2013)."
BMGC_PW1483,BMG_PW4128,,,"The 22 tRNAs encoded by the mitochondrial genome are modified in the mitochondrial matrix by enzymes encoded in the nucleus and imported into mitochondria (reviewed in Suzuki et al. 2011, Salinas-Giege et al. 2015). Some enzymes such as PUS1 and TRIT1 are located in more than one compartment and modify both mitochondrial tRNAs and cytosolic tRNAs. Other enzymes such as MTO1, TRMU, and TRMT61B are exclusively mitochondrial. Modifications near the anticodon and near the 3' end of tRNAs tend to affect interaction of the tRNA with mRNA within ribosomes and with tRNA synthetases, respectively. Modifications in other regions, typically in the ""core"" of the tRNA tend to affect folding and stability of the tRNA (reviewed in Hou et al. 2015). The unusual modification 5-taurinomethyl-2-thiouridine-34 in the anticodon of at least 3 tRNAs is found only in mammalian mitochondria and mutations that affect the responsible biosynthetic enzymes (GTPBP3, MTO1, TRMU) cause mitochondrial dysfunction and disease (reviewed in Torres et al. 2014)."
BMGC_PW1484,BMG_PW4130,,,"The members involved in (interleukin)-6-type cytokine signalling are the IL-6, IL-11, LIF (leukaemia inhibitory factor), OSM (oncostatin M), ciliary neurotrophic factor (CNTF), cardiotrophin-1 (CTF1) and cardiotrophin-like cytokine factor 1 (CLCF1). Receptors involved in recognition of the IL-6-type cytokines can be subdivided in the non-signalling alpha-receptors (IL6R, IL 11R, and CNTFR) and the signal transducing receptors (gp130, LIFR, and OSMR). The latter associate with JAKs and become tyrosine phosphorylated in response to cytokine stimulation (Heinrich et al. 1998, 2003). IL27 and IL35 belongs to IL12 cytokine family but they share gp130 as a component of signalling receptor, along with IL-6, IL-11, LIF, OSM, CNTF, CTF1 and CLCF1."
BMGC_PW1485,BMG_PW4131,,,"Human ribosomal RNAs (rRNAs) contain about 200 residues that are enzymatically modified after transcription in the nucleolus (Maden and Khan 1977, Maden 1988, Maden and Hughes 1997, reviewed in Hernandez-Verdun et al. 2010, Boschi-Muller and Motorin 2013). The modified residues occur in regions of the rRNAs that are located in functionally important parts of the ribosome, notably in the A and P peptidyl transfer sites, the polypeptide exit tunnel, and intersubunit contacts (Polikanov et al. 2015, reviewed in Decatur and Fournier 2002, Chow et al. 2007, Sharma and Lafontaine 2015). The two most common modifications are pseudouridines and 2'-O-methylribonucleotides. Formation of pseudouridine from encoded uridine is catalyzed by box H/ACA small nucleolar ribonucleoprotein (snoRNP) complexes (reviewed in Hamma and Ferre-D'Amare 2010, Watkins and Bohnsack 2011, Ge and Yu 2013, Kierzek et al. 2014, Yu and Meier 2014) and methylation of the hydroxyl group of the 2' carbon is catalyzed by box C/D snoRNPs (Kiss-Laszlo et al. 1996, Lapinaite et al. 2013, reviewed in Watkins and Bohnsack 2011). The snoRNP complexes contain common sets of protein subunits and unique snoRNAs that guide each complex to its target nucleotide of the rRNA by base-pairing between the snoRNA and the rRNA (reviewed in Henras et al. 2004, Watkins and Bohnsack 2011). Other modifications of rRNA include 5-methylcytidine (reviewed in Squires and Preiss 2010), 1-methylpseudouridine, 7-methylguanosine, 6-dimethyladenosine, and 4-acetylcytidine (reviewed in Sharma and Lafontaine 2015). In yeast most modifications are introduced co-transcriptionally (Kos and Tollervey 2010, reviewed in Turowski and Tollervey 2015), however the order of modification events and pre-rRNA cleavage events is not well characterized."
BMGC_PW1486,BMG_PW4133,,,"In humans, a 47S precursor rRNA (pre-rRNA) is transcribed by RNA polymerase I from rRNA-encoding genes (rDNA) at the boundary of the fibrillar center and the dense fibrillar components of the nucleolus (Stanek et al. 2001). The 47S precursor is processed over the course of about 5-8 minutes (Popov et al. 2013) by endoribonucleases and exoribonucleases to yield the 28S rRNA and 5.8S rRNA of the 60S subunit and the 18S rRNA of the 40S subunit (reviewed in Mullineus and Lafontaine 2012, Henras et al. 2015). As the pre-rRNA is being transcribed, a large protein complex, the small subunit (SSU) processome, assembles in the region of the 18S rRNA sequence, forming terminal knobs on the pre-rRNA (reviewed in Phipps et al. 2011, inferred from yeast in Dragon et al. 2002). The SSU processome contains both ribosomal proteins of the small subunit and processing factors which process the pre-rRNA and modify nucleotides. Through addition of subunits the SSU processome appears to be converted into the larger 90S pre-ribosome (inferred from yeast in Grandi et al. 2002). An analogous large subunit processome (LSU) assembles in the region of the 28S rRNA, however the LSU is less well characterized (inferred from yeast in McCann et al. 2015). Following cleavage of the pre-rRNA within internal transcribed spacer 1 (ITS1), the pre-ribosomal particle separates into a pre-60S subunit and a pre-40S subunit in the nucleolus (reviewed in Hernandez-Verdun et al. 2010, Phipps et al. 2011). The pre-60S and pre-40S ribosomal particles are then exported from the nucleus to the cytoplasm where the processing factors dissociate and recycle back to the nucleus Nuclease digestions of the 47S pre-rRNA can follow several paths. In the major pathway, the ends of the 47S pre-rRNA are trimmed to yield the 45S pre-rRNA. Digestion at site 2 (also called site 2b in mouse, see Henras et al. 2015 for nomenclature) cleaves the 45S pre-rRNA to yield the 30S pre-rRNA containing the 18S rRNA of the small subunit and the 32S pre-rRNA containing the 5.8S rRNA and the 28S rRNA of the large subunit. The 32S pre-rRNA is digested in the nucleus to yield the 5.8S rRNA and the 28S rRNA while the 30S pre-rRNA is digested in the nucleus to yield the 18SE pre-rRNA which is then processed in the nucleus and cytosol to yield the 18S rRNA. At least 286 human proteins, 74 of which have no yeast homolog, are required for efficient processing of pre-rRNA in the nucleus (Tafforeau et al. 2013)"
BMGC_PW1487,BMG_PW4134,,,
BMGC_PW1488,BMG_PW4139,,,"Neurexins (NRXNs) and neuroligins (NLGNs) are best characterized synaptic cell-adhesion molecules. They are part of excitatory glutamatergic and inhibitory GABAergic synapses in mammalian brain, mediate trans-synaptic signaling, and shape neural network properties by specifying synaptic functions. As cell-adhesion molecules, NRXNs and NLGNs probably function by binding to each other and by interacting with intracellular PDZ-domain proteins, but the precise mechanisms involved and their relation to synaptic transmission remain unclear. The binding of NRXNs and NLGNs to their partners, helps to align the pre-synaptic release machinery and post-synaptic receptors. The importance of neurexins and neuroligins for synaptic function is evident from the dramatic deficits in synaptic transmission in mice lacking Nrxns or Nlgns. In humans, alterations in NRXNs or NLGNs genes are implicated in autism and other cognitive diseases, connecting synaptic cell adhesion to cognition and its disorders (Sudhof 2008, Craig et al. 2006, Craig & Kang 2007)."
BMGC_PW1489,BMG_PW4140,,,"Synapses constitute highly specialized sites of asymmetric cell-cell adhesion and intercellular communication. Its formation involves the recruitment of presynaptic and postsynaptic molecules at newly formed contacts. Synapse assembly and maintenance invokes heterophilic presynaptic and postsynaptic transmembrane proteins that bind each other in the extracellular space and recruit additional proteins via their intracellular domains. Members of the cadherin and immunoglobulin (Ig) superfamilies are thought to mediate this function. Several molecules, including synaptic cell-adhesion molecule (SynCAM), N-cadherin, neural cell-adhesion molecule (NCAM), Eph receptor tyrosine kinases, and neuroligins and neurexins, have been implicated in synapse formation and maintenance (Dean & Dresbach 2006, Craig et al. 2006, Craig & Kang 2007, Sudhof 2008)."
BMGC_PW1490,BMG_PW4141,,,"Several DNA repair genes contain p53 response elements and their transcription is positively regulated by TP53 (p53). TP53-mediated regulation probably ensures increased protein level of DNA repair genes under genotoxic stress. TP53 directly stimulates transcription of several genes involved in DNA mismatch repair, including MSH2 (Scherer et al. 2000, Warnick et al. 2001), PMS2 and MLH1 (Chen and Sadowski 2005). TP53 also directly stimulates transcription of DDB2, involved in nucleotide excision repair (Tan and Chu 2002), and FANCC, involved in the Fanconi anemia pathway that repairs DNA interstrand crosslinks (Liebetrau et al. 1997). Other p53 targets that can influence DNA repair functions are RRM2B (Kuo et al. 2012), XPC (Fitch et al. 2003), GADD45A (Amundson et al. 2002), CDKN1A (Cazzalini et al. 2010) and PCNA (Xu and Morris 1999). Interestingly, the responsiveness of some of these DNA repair genes to p53 activation has been shown in human cells but not for orthologous mouse genes (Jegga et al. 2008, Tan and Chu 2002). Contrary to the positive modulation of nucleotide excision repair (NER) and mismatch repair (MMR), p53 can negatively modulate base excision repair (BER), by down-regulating the endonuclease APEX1 (APE1), acting in concert with SP1 (Poletto et al. 2016). Expression of several DNA repair genes is under indirect TP53 control, through TP53-mediated stimulation of cyclin K (CCNK) expression (Mori et al. 2002). CCNK is the activating cyclin for CDK12 and CDK13 (Blazek et al. 2013). The complex of CCNK and CDK12 binds and phosphorylates the C-terminal domain of the RNA polymerase II subunit POLR2A, which is necessary for efficient transcription of long DNA repair genes, including BRCA1, ATR, FANCD2, FANCI, ATM, MDC1, CHEK1 and RAD51D. Genes whose transcription is regulated by the complex of CCNK and CDK12 are mainly involved in the repair of DNA double strand breaks and/or the Fanconi anemia pathway (Blazek et al. 2011, Cheng et al. 2012, Bosken et al. 2014, Bartkowiak and Greenleaf 2015, Ekumi et al. 2015)."
BMGC_PW1491,BMG_PW4142,,,"Neutrophils are the most abundant leukocytes (white blood cells), indispensable in defending the body against invading microorganisms. In response to infection, neutrophils leave the circulation and migrate towards the inflammatory focus. They contain several subsets of granules that are mobilized to fuse with the cell membrane or phagosomal membrane, resulting in the exocytosis or exposure of membrane proteins. Traditionally, neutrophil granule constituents are described as antimicrobial or proteolytic, but granules also introduce membrane proteins to the cell surface, changing how the neutrophil responds to its environment (Borregaard et al. 2007). Primed neutrophils actively secrete cytokines and other inflammatory mediators and can present antigens via MHC II, stimulating T-cells (Wright et al. 2010). Granules form during neutrophil differentiation. Granule subtypes can be distinguished by their content but overlap in structure and composition. The differences are believed to be a consequence of changing protein expression and differential timing of granule formation during the terminal processes of neutrophil differentiation, rather than sorting (Le Cabec et al. 1996). The classical granule subsets are Azurophil or primary granules (AG), secondary granules (SG) and gelatinase granules (GG). Neutrophils also contain exocytosable storage cell organelles, storage vesicles (SV), formed by endocytosis they contain many cell-surface markers and extracellular, plasma proteins (Borregaard et al. 1992). Ficolin-1-rich granules (FG) are like GGs highly exocytosable but gelatinase-poor (Rorvig et al. 2009)."
BMGC_PW1492,BMG_PW4143,,,"Complex I (NADH:ubiquinone oxidoreductase or NADH dehydrogenase) utilises NADH formed from glycolysis and the TCA cycle to pump protons out of the mitochondrial matrix. It is the largest enzyme complex in the electron transport chain, containing 11 core and 34 accessory subunits. Seven subunits (ND1-6, ND4L) are encoded by mitochondrial DNA, the remainder are encoded in the nucleus. The enzyme has a FMN prosthetic group and 8 Iron-Sulfur (Fe-S) clusters. The subunits are assembled together in a coordinated manner via preassembled subcomplexes to form the mature holoenzyme. At least 24 so-called ""assembly factor"" proteins, acting intrinsically or transiently, are required for constructing complex I although their exact roles in the biogenesis are not fully understood (Fernandez-Vizarra et al. 2009, Mckenzie & Ryan 2010, Mimaki et al. 2012, Andrews et al. 2013; reviewed by Laube et al., 2024)."
BMGC_PW1493,BMG_PW4144,,,"Metals are necessary for all forms of life including microorganisms, evidenced by the fact that metal cations are constituents of approximately 40% of all proteins crystallized to date (Waldron KJ et al. 2009; Foster AW et al. 2014; Guengerich FP 2014, 2015). The ability of microorganisms to maintain the intracellular metal quota is essential and allows microorganisms to adapt to a variety of environments. Accordingly, the ability of the host to control metal quota at inflammation sites can influence host-pathogen interactions. The host may restrict microbial growth either by excluding essential metals from the microbes, by delivery of excess metals to cause toxicity, or by complexing metals in microorganisms (Becker KW & Skaar EP 2014)."
BMGC_PW1494,BMG_PW4145,,,"In addition to the highly prevalent and activating V600E BRAF mutations, numerous moderately activating and less common mutations have also been identified in human cancers (Forbes et al, 2015). Unlike the case for their highly activating counterparts, signaling through these mutant versions of BRAF depends both upon RAS binding and RAF dimerization (Wan et al, 2004; Freeman et al, 2013; Roring et al, 2012; reviewed in Lito et al, 2013; Lavoie and Therrien, 2015)"
BMGC_PW1495,BMG_PW4146,,,"BRAF is mutated in about 8% of human cancers, with high prevalence in hairy cell leukemia, melanoma, papillary thyroid and ovarian carcinomas, colorectal cancer and a variety of other tumors (Davies et al, 2002; reviewed in Samatar and Poulikakos, 2014). Most BRAF mutations fall in the activation loop region of the kinase or the adjacent glycine rich region. These mutations promote increased kinase activity either by mimicking the effects of activation loop phosphorylations or by promoting the active conformation of the enzyme (Davies et al, 2002; Wan et al, 2004). Roughly 90% of BRAF mutants are represented by the single missense mutation BRAF V600E (Davies et al, 2002; Wan et al, 2004). Other highly active kinase mutants of BRAF include BRAF G469A and BRAF T599dup. G469 is in the glycine rich region of the kinase domain which plays a role in orienting ATP for catalysis, while T599 is one of the two conserved regulatory phosphorylation sites of the activation loop. Each of these mutants has highly enhanced basal kinase activities, phosphorylates MEK and ERK in vitro and in vivo and is transforming when expressed in vivo (Davies et al, 2002; Wan et al, 2004; Eisenhardt et al, 2011). Further functional characterization shows that these highly active mutants are largely resistant to disruption of the BRAF dimer interface, suggesting that they are able to act as monomers (Roring et al, 2012; Brummer et al, 2006; Freeman et al, 2013; Garnett et al, 2005). Activating BRAF mutations occur for the most part independently of RAS activating mutations, and RAS activity levels are generally low in BRAF mutant cells. Moreover, the kinase activity of these mutants is only slightly elevated by coexpression of G12V KRAS, and biological activity of the highly active BRAF mutants is independent of RAS binding (Brummer et al, 2006; Wan et al, 2004; Davies et al, 2002; Garnett et al, 2005). Although BRAF V600E is inhibited by RAF inhibitors such as vemurafenib, resistance frequently develops, in some cases mediated by the expression of a splice variant that lacks the RAS binding domain and shows elevated dimerization compared to the full length V600E mutant (Poulikakos et al, 2011; reviewed in Lito et al, 2013)."
BMGC_PW1496,BMG_PW4147,,,"Members of the RAS gene family were the first oncogenes to be identified, and mutations in RAS are present in ~20-30% of human cancers (reviewed in Prior et al, 2012). Mutations in the KRAS gene are the most prevalent, and are found with high frequency in colorectal cancer, non-small cell lung cancer and pancreatic cancer, among others. The reasons for the lower prevalence of HRAS and NRAS mutations in human cancers are not fully understood, but may reflect gene-specific functions as well as differential codon usage and spatio-temporal regulation (reviewed in Prior et al, 2012; Stephen et al, 2014; Pylayeva-Gupta et al, 2011). Activating RAS mutations contribute to cellular proliferation, transformation and survival by activating the MAPK signaling pathway, the AKT pathway and the RAL GDS pathway, among others (reviewed in Stephen et al, 2014; Pylayeva-Gupta et al, 2011). Although the frequency and distribution varies between RAS genes and cancer types, the vast majority of activating RAS mutations occur at one of three residues - G12, G13 and Q61. Mutations at these sites favour the RAS:GTP bound form and yield constitutively active versions of the protein (reviewed in Prior et al, 2012)."
BMGC_PW1497,BMG_PW4148,,,"In addition to the more prevalent point mutations, BRAF and RAF1 are also subject to activation as a result of translocation events that yield truncated or fusion products (Jones et al, 2008; Cin et al, 2011; Palanisamy et al, 2010; Ciampi et al, 2005; Stransky et al, 2014; Hutchinson et al, 2013; Zhang et al, 2013; Lee et al, 2012; Ricarte-Filho et al, 2013; reviewed in Lavoie and Therrien et al, 2015). In general these events put the C-terminal kinase domain of BRAF or RAF1 downstream of an N-terminal sequence provided by a partner protein. This removes the N-terminal region of the RAF protein, relieving the autoinhibition imposed by this region of the protein. In addition, some but not all of the fusion partner proteins have been shown to contain coiled-coil or other dimerization domains. Taken together, the fusion proteins are thought to dimerize constitutively and activate downstream signaling (Jones et al, 2008; Lee et al, 2012; Hutchinson et al, 2013; Ciampi et al, 2005; Cin et al, 2011; Stransky et al, 2014)."
BMGC_PW1498,BMG_PW4149,,,"NF1 is a RAS GAP that stimulates the intrinsic RAS GTPase activity, thereby shifting the RAS pathway towards the inactive state (reviewed in King et al, 2013). Loss-of-function mutations in NF1 have been identified both in germline diseases like neurofibromatosis 1 and in a range of sporadically occurring cancers. These mutations, which range from complete gene deletions to missense or frameshift mutations, generally decrease NF1 protein levels and abrogate RAS GAP activity in the cells, resulting in constitutive RAS pathway activation (reviewed in Maertens and Cichowski, 2014; Tidyman and Rauen, 2009; Ratner and Miller, 2015)."
BMGC_PW1499,BMG_PW4150,,,"While BRAF-specific inhibitors inhibit MAPK/ERK activation in the presence of the BRAF V600E mutant, paradoxical activation of ERK signaling has been observed after treatment of cells with inhibitor in the presence of WT BRAF (Wan et al, 2004; Garnett et al, 2005; Heidorn et al, 2010; Hazivassiliou et al, 2010; Poulikakos et al, 2010). This paradoxical ERK activation is also seen in cells expressing kinase-dead or impaired versions of BRAF such as D594V, which occur with low frequency in some cancers (Wan et al, 2004; Heidorn et al, 2010). Unlike BRAF V600E, which occurs exclusively of activating RAS mutations, kinase-impaired versions of BRAF are coincident with RAS mutations in human cancers, and indeed, paradoxical activation of ERK signaling in the presence of inactive BRAF is enhanced in the presence of oncogenic RAS (Heidorn et al, 2010; reviewed in Holderfield et al, 2014). Although the details remain to be worked out, paradoxical ERK activation in the presence of inactive BRAF appears to rely on enhanced dimerization with and transactivation of CRAF (Heidorn et al, 2010; Hazivassiliou et al, 2010; Poulikakos et al, 2010; Roring et al, 2012; Rajakulendran et al, 2009; Holderfield et al, 2013; Freeman et al, 2013; reviewed in Roskoski, 2010; Samatar and Poulikakos, 2014; Lavoie and Therrien, 2015). RAF inhibitors can promote association of RAF-RAS interaction and enhanced RAF dimerization through disruption of intramolecular interactions between the kinase domain and its N-terminal regulatory region. Moreover, specific BRAF inhibitors can only occupy one protomer within the transcactivated BRAF dimer due to negative co-operativity leading to paradoxical ERK activation. (Karoulia et al, 2016; Jin et al, 2017, reviewed in Karoulia et al, 2017)."
BMGC_PW1500,BMG_PW4151,,,"The importance of the RAS/RAF/MAPK cascade in regulating cellular proliferation, differentiation and survival is highlighted by the fact that components of the pathway are mutated with high frequency in a large number of human cancers. Activating mutations in RAS are found in approximately one third of human cancers, while ~8% of tumors express an activated form of BRAF. RAS pathway activation is also achieved in a smaller subset of cancers by loss-of-function mutations in negative regulators of RAS signaling, such as the RAS GAP NF1(reviewed in Prior et al, 2012; Pylayeva-Gupta et al, 2011; Stephen et al, 2014; Lavoie and Therrien, 2015; Lito et al, 2013; Samatar and Poulikakos, 2014; Maertens and Cichowski, 2014)."
BMGC_PW1501,BMG_PW4152,,,"Antimicrobial peptides (AMPs) are small molecular weight proteins with broad spectrum of antimicrobial activity against bacteria, viruses, and fungi (Zasloff M 2002; Radek K & Gallo R 2007). The majority of known AMPs are cationic peptides with common structural characteristics where domains of hydrophobic and cationic amino acids are spatially arranged into an amphipathic design, which facilitates their interaction with bacterial membranes (Shai Y 2002; Yeaman MR & Yount NY 2003; Brown KL & Hancock RE 2006; Dennison SR et al. 2005; Zelezetsky I & Tossi A 2006). It is generally excepted that the electrostatic interaction facilitates the initial binding of the positively charged peptides to the negatively charged bacterial membrane. Moreover, the structural amphiphilicity of AMPs is thought to promote their integration into lipid bilayers of pathogenic cells, leading to membrane disintegration and finally to the microbial cell death. In addition to cationic AMPs a few anionic antimicrobial peptides have been found in humans, however their mechanism of action remains to be clarified (Lai Y et al. 2007; Harris F et al. 2009; Paulmann M et al. 2012). Besides the direct neutralizing effects on bacteria AMPs may modulate cells of the adaptive immunity (neutrophils, T-cells, macrophages) to control inflammation and/or to increase bacterial clearance. AMPs have also been referred to as cationic host defense peptides, anionic antimicrobial peptides/proteins, cationic amphipathic peptides, cationic AMPs, host defense peptides and alpha-helical antimicrobial peptides (Brown KL & Hancock RE 2006; Harris F et al. 2009; Groenink J et al. 1999; Bradshaw J 2003; Riedl S et al. 2011; Huang Y et al. 2010). The Reactome module describes the interaction events of various types of human AMPs, such as cathelicidin, histatins and neutrophil serine proteases, with conserved patterns of microbial membranes at the host-pathogen interface. The module includes also proteolytic processing events for dermcidin (DCD) and cathelicidin (CAMP) that become functional upon cleavage. In addition, the module highlights an AMP-associated ability of the host to control metal quota at inflammation sites to influence host-pathogen interactions."
BMGC_PW1502,BMG_PW4153,,,"Apoptotic transcriptional targets of TP53 include genes that regulate the permeability of the mitochondrial membrane and/or cytochrome C release, such as BAX, BID, PMAIP1 (NOXA), BBC3 (PUMA) and probably BNIP3L, AIFM2, STEAP3, TRIAP1 and TP53AIP1 (Miyashita and Reed 1995, Oda et al. 2000, Samuels-Lev et al. 2001, Nakano and Vousden 2001, Sax et al. 2002, Passer et al. 2003, Bergamaschi et al. 2004, Li et al. 2004, Fei et al. 2004, Wu et al. 2004, Park and Nakamura 2005, Patel et al. 2008, Wang et al. 2012, Wilson et al. 2013), thus promoting the activation of the apoptotic pathway. Transcriptional activation of TP53AIP1 requires phosphorylation of TP53 at serine residue S46 (Oda et al. 2000, Taira et al. 2007). Phosphorylation of TP53 at S46 is regulated by another TP53 pro-apoptotic target, TP53INP1 (Okamura et al. 2001, Tomasini et al. 2003)."
BMGC_PW1503,BMG_PW4154,,,"The exact mechanisms of action of several other pro-apoptotic TP53 (p53) targets, such as TP53I3 (PIG3), RABGGTA, BCL2L14, BCL6, NDRG1 and PERP, remain uncertain (Attardi et al. 2000, Guo et al. 2001, Samuels-Lev et al. 2001, Contente et al. 2002, Ihrie et al. 2003, Bergamaschi et al. 2004, Stein et al. 2004, Phan and Dalla-Favera 2004, Jen and Cheung 2005, Margalit et al. 2006, Zhang et al. 2007, Saito et al. 2009, Davies et al. 2009, Giam et al. 2012)."
BMGC_PW1504,BMG_PW4155,,,"TP53 (p53) transcriptionally regulates cytosolic caspase activators, such as APAF1, PIDD1, and NLRC4, and caspases themselves, such as CASP1, CASP6 and CASP10. These caspases and their activators are involved either in the intrinsic apoptosis pathway or in the extrinsic apoptosis pathway triggerred by death receptors or the inflammation-related cell death pyroptosis (Lin et al. 2000, Robles et al. 2001, Gupta et al. 2001, MacLachlan and El-Deiry 2002, Rikhof et al. 2003, Sadasivam et al. 2005, Brough and Rothwell 2007)."
BMGC_PW1505,BMG_PW4156,,,"Pro-apoptotic transcriptional targets of TP53 are TRAIL death receptors TNFRSF10A (DR4), TNFRSF10B (DR5), TNFRSF10C (DcR1) and TNFRSF10D (DcR2), as well as the FASL/CD95L death receptor FAS (CD95). TRAIL receptors and FAS induce pro-apoptotic signaling in response to external stimuli via extrinsic apoptosis pathway (Wu et al. 1997, Takimoto et al. 2000, Guan et al. 2001, Liu et al. 2004, Ruiz de Almodovar et al. 2004, Liu et al. 2005, Schilling et al. 2009, Wilson et al. 2013). IGFBP3 is a transcriptional target of TP53 that may serve as a ligand for a novel death receptor TMEM219 (Buckbinder et al. 1995, Ingermann et al. 2010)."
BMGC_PW1506,BMG_PW4157,,,"Alternative splicing of the FGFR2 nascent mRNA generates an epithelial specific isoform (FGFR2 IIIb) and a mesenchymal specific isoform (FGFR2 IIIc). The inclusion of exon 8 in FGFR2 IIIb or exon 9 in FGFR2 IIIc alters the C-terminal half of the D3 loop of the receptor and is responsible for the different ligand-binding specificities of the two isoforms (reviewed in Eswarakumar et al, 2005). In recent years, a number of cis- and trans-acting elements have been identified that regulate the alternative splicing event. Exon IIIb repression is mediated by the presence of weak splice sites flanking the exon, an exonic silencing sequence (ESS) within the IIIb exon and both intronic silencing sequences (ISS) upstream and downstream (Carstens et al, 2000; Del Gatto and Breathnach, 1995; Del Gatto et al, 1996; Wagner et al 2005; Wagner and Garcia-Blanco, 2001). Binding of hnRNPA1, PTB1, SR family proteins and other factors to these elements represses the IIIb exon and promotes FGFR2 IIIc expression in mesenchymal cells (Del Gatto-Konczak et al, 1999; Carstens et al, 2000; Wagner et al, 2005; Wagner and Garcia-Blanco, 2001; Wagner and Garcia-Blanco, 2002). In epithelial cells, recruitment of epithelial specific factors shifts the splicing events to favour inclusion of exon 8. ESPN1 and ESPN2 are epithelial-specific factors that bind to an ISE/ISS-3 (intronic splicing enhancer/intronic splicing silencer-3) region within intron 8 to promote FGFR2 IIIb-specific splicing (Warzecha et al, 2009). A complex of RBFOX2, hnRNPH1 and hnRNPF also contribute to epithelial-specific splicing by competing for binding to a site that is occupied by the SR proteins ASF/SF2 in mesenchymal cells (Baraniak et al, 2006; Mauger et al, 2008). Other proteins and sequences have also been identified that appear to contribute to the regulated expression of FGFR2b and FGFR2c, but the full details of the alternative splicing event remain to be worked out (Muh et al, 2002; Newman et al, 2006; Del Gatto et al, 2000; Hovhannisyan and Carstens, 2007)."
BMGC_PW1507,BMG_PW4159,,,"TP53 contributes to the establishment of G2 arrest by inducing transcription of GADD45A and SFN, and by inhibiting transcription of CDC25C. TP53 induces GADD45A transcription in cooperation with chromatin modifying enzymes EP300, PRMT1 and CARM1 (An et al. 2004). GADD45A binds Aurora kinase A (AURKA), inhibiting its catalytic activity and preventing AURKA-mediated G2/M transition (Shao et al. 2006, Sanchez et al. 2010). GADD45A also forms a complex with PCNA. PCNA is involved in both normal and repair DNA synthesis. The effect of GADD45 interaction with PCNA, if any, on S phase progression, G2 arrest and DNA repair is not known (Smith et al. 1994, Hall et al. 1995, Sanchez et al. 2010, Kim et al. 2013). SFN (14-3-3-sigma) is induced by TP53 (Hermeking et al. 1997) and contributes to G2 arrest by binding to the complex of CDK1 and CCNB1 (cyclin B1) and preventing its translocation to the nucleus. Phosphorylation of a number of nuclear proteins by the complex of CDK1 and CCNB1 is needed for G2/M transition (Chan et al. 1999). While promoting G2 arrest, SFN can simultaneously inhibit apoptosis by binding to BAX and preventing its translocation to mitochondria, a step involved in cytochrome C release (Samuel et al. 2001). TP53 binds the promoter of the CDC25C gene in cooperation with the transcriptional repressor E2F4 and represses CDC25C transcription, thus maintaining G2 arrest (St Clair et al. 2004, Benson et al. 2014). The zinc finger transcription factor ZNF385A (HZF) is a direct transcriptional target of TP53 that can form a complex with TP53 and facilitate TP53-mediated induction of SFN transcription (Das et al. 2007)."
BMGC_PW1508,BMG_PW4160,,,"BTG2 is induced by TP53, leading to cessation of cellular proliferation (Rouault et al. 1996, Duriez et al. 2002). BTG2 binds to the CCR4-NOT complex and promotes mRNA deadenylation activity of this complex. Interaction between BTG2 and CCR4-NOT is needed for the antiproliferative activity of BTG2, but the underlying mechanism has not been elucidated (Rouault et al. 1998, Mauxion et al. 2008, Horiuchi et al. 2009, Doidge et al. 2012, Ezzeddine et al. 2012). Two polo-like kinases, PLK2 and PLK3, are direct transcriptional targets of TP53. TP53-mediated induction of PLK2 may be important for prevention of mitotic catastrophe after spindle damage (Burns et al. 2003). PLK2 is involved in the regulation of centrosome duplication through phosphorylation of centrosome-related proteins CENPJ (Chang et al. 2010) and NPM1 (Krause and Hoffmann 2010). PLK2 is frequently transcriptionally silenced through promoter methylation in B-cell malignancies (Syed et al. 2006). Induction of PLK3 transcription by TP53 (Jen and Cheung 2005) may be important for coordination of M phase events through PLK3-mediated nuclear accumulation of CDC25C (Bahassi et al. 2004). RGCC is induced by TP53 and implicated in cell cycle regulation, possibly through its association with PLK1 (Saigusa et al. 2007). PLAGL1 (ZAC1) is a zinc finger protein directly transcriptionally induced by TP53 (Rozenfeld-Granot et al. 2002). PLAGL1 expression is frequently lost in cancer (Varrault et al. 1998) and PLAGL1 has been implicated in both cell cycle arrest and apoptosis (Spengler et al. 1997), but its mechanism of action remains unknown."
BMGC_PW1509,BMG_PW4161,,,"The most prominent TP53 target involved in G1 arrest is the inhibitor of cyclin-dependent kinases CDKN1A (p21). CDKN1A is one of the earliest genes induced by TP53 (El-Deiry et al. 1993). CDKN1A binds and inactivates CDK2 in complex with cyclin A (CCNA) or E (CCNE), thus preventing G1/S transition (Harper et al. 1993). Considering its impact on the cell cycle outcome, CDKN1A expression levels are tightly regulated. For instance, under prolonged stress, TP53 can induce the transcription of an RNA binding protein PCBP4, which can bind and destabilize CDKN1A mRNA, thus alleviating G1 arrest and directing the affected cell towards G2 arrest and, possibly, apoptosis (Zhu and Chen 2000, Scoumanne et al. 2011). Expression of E2F7 is directly induced by TP53. E2F7 contributes to G1 cell cycle arrest by repressing transcription of E2F1, a transcription factor that promotes expression of many genes needed for G1/S transition (Aksoy et al. 2012, Carvajal et al. 2012). ARID3A is a direct transcriptional target of TP53 (Ma et al. 2003) that may promote G1 arrest by cooperating with TP53 in induction of CDKN1A transcription (Lestari et al. 2012). However, ARID3A may also promote G1/S transition by stimulating transcriptional activity of E2F1 (Suzuki et al. 1998, Peeper et al. 2002). TP53 has co-factors that are key determinants of transcriptional selectivity within the p53 network. For instance, the zinc finger transcription factor ZNF385A (HZF) is a direct transcriptional target of TP53 that can form a complex with TP53 and facilitate TP53-mediated induction of CDKN1A, strongly favouring cell cycle arrest over apoptosis (Das et al. 2007)."
BMGC_PW1510,BMG_PW4163,,,"Phosphorylation of TP53 (p53) at the N-terminal serine residues S15 and S20 plays a critical role in protein stabilization as phosphorylation at these sites interferes with binding of the ubiquitin ligase MDM2 to TP53. Several different kinases can phosphorylate TP53 at S15 and S20. In response to double strand DNA breaks, S15 is phosphorylated by ATM (Banin et al. 1998, Canman et al. 1998, Khanna et al. 1998), and S20 by CHEK2 (Chehab et al. 1999, Chehab et al. 2000, Hirao et al. 2000). DNA damage or other types of genotoxic stress, such as stalled replication forks, can trigger ATR-mediated phosphorylation of TP53 at S15 (Lakin et al. 1999, Tibbetts et al. 1999) and CHEK1-mediated phosphorylation of TP53 at S20 (Shieh et al. 2000). In response to various types of cell stress, NUAK1 (Hou et al. 2011), CDK5 (Zhang et al. 2002, Lee et al. 2007, Lee et al. 2008), AMPK (Jones et al. 2005) and TP53RK (Abe et al. 2001, Facchin et al. 2003) can phosphorylate TP53 at S15, while PLK3 (Xie, Wang et al. 2001, Xie, Wu et al. 2001) can phosphorylate TP53 at S20. Phosphorylation of TP53 at serine residue S46 promotes transcription of TP53-regulated apoptotic genes rather than cell cycle arrest genes. Several kinases can phosphorylate S46 of TP53, including ATM-activated DYRK2, which, like TP53, is targeted for degradation by MDM2 (Taira et al. 2007, Taira et al. 2010). TP53 is also phosphorylated at S46 by HIPK2 in the presence of the TP53 transcriptional target TP53INP1 (D'Orazi et al. 2002, Hofmann et al. 2002, Tomasini et al. 2003). CDK5, in addition to phosphorylating TP53 at S15, also phosphorylates it at S33 and S46, which promotes neuronal cell death (Lee et al. 2007). MAPKAPK5 (PRAK) phosphorylates TP53 at serine residue S37, promoting cell cycle arrest and cellular senescence in response to oncogenic RAS signaling (Sun et al. 2007). NUAK1 phosphorylates TP53 at S15 and S392, and phosphorylation at S392 may contribute to TP53-mediated transcriptional activation of cell cycle arrest genes (Hou et al. 2011). S392 of TP53 is also phosphorylated by the complex of casein kinase II (CK2) bound to the FACT complex, enhancing transcriptional activity of TP53 in response to UV irradiation (Keller et al. 2001, Keller and Lu 2002). The activity of TP53 is inhibited by phosphorylation at serine residue S315, which enhances MDM2 binding and degradation of TP53. S315 of TP53 is phosphorylated by Aurora kinase A (AURKA) (Katayama et al. 2004) and CDK2 (Luciani et al. 2000). Interaction with MDM2 and the consequent TP53 degradation is also increased by phosphorylation of TP53 threonine residue T55 by the transcription initiation factor complex TFIID (Li et al. 2004). Aurora kinase B (AURKB) has been shown to phosphorylate TP53 at serine residue S269 and threonine residue T284, which is possibly facilitated by the binding of the NIR co-repressor. AURKB-mediated phosphorylation was reported to inhibit TP53 transcriptional activity through an unknown mechanism (Wu et al. 2011). A putative direct interaction between TP53 and AURKB has also been described and linked to TP53 phosphorylation and S183, T211 and S215 and TP53 degradation (Gully et al. 2012)."
BMGC_PW1511,BMG_PW4164,,,"In unstressed cells, TP53 (p53) has a short half-life as it undergoes rapid ubiquitination and proteasome-mediated degradation. The E3 ubiquitin ligase MDM2, which is a transcriptional target of TP53, plays the main role in TP53 protein down-regulation (Wu et al. 1993). MDM2 forms homodimers and homo-oligomers, but also functions as a heterodimer/hetero-oligomer with MDM4 (MDMX) (Sharp et al. 1999, Cheng et al. 2011, Huang et al. 2011, Pant et al. 2011). The heterodimers of MDM2 and MDM4 may be especially important for downregulation of TP53 during embryonic development (Pant et al. 2011). The nuclear localization of MDM2 is positively regulated by AKT- or SGK1- mediated phosphorylation (Mayo and Donner 2001, Zhou et al. 2001, Amato et al. 2009, Lyo et al. 2010). Phosphorylation of MDM2 by CDK1 or CDK2 decreases affinity of MDM2 for TP53 (Zhang and Prives 2001). ATM and CHEK2 kinases, activated by double strand DNA breaks, phosphorylate TP53, reducing its affinity for MDM2 (Banin et al. 1998, Canman et al. 1998, Khanna et al. 1998, Chehab et al. 1999, Chehab et al. 2000). At the same time, ATM phosphorylates MDM2, preventing MDM2 dimerization (Cheng et al. 2009, Cheng et al. 2011). Both ATM and CHEK2 phosphorylate MDM4, triggering MDM2-mediated ubiquitination of MDM4 (Chen et al. 2005, Pereg et al. 2005). Cyclin G1 (CCNG1), transcriptionally induced by TP53, targets the PP2A phosphatase complex to MDM2, resulting in dephosphorylation of MDM2 at specific sites, which can have either a positive or a negative impact on MDM2 function (Okamoto et al. 2002). In contrast to MDM2, E3 ubiquitin ligases RNF34 (CARP1) and RFFL (CARP2) can ubiquitinate phosphorylated TP53 (Yang et al. 2007). In addition to ubiquitinating MDM4 (Pereg et al. 2005), MDM2 can also undergo auto-ubiquitination (Fang et al. 2000). MDM2 and MDM4 can be deubiquitinated by the ubiquitin protease USP2 (Stevenson et al. 2007, Allende-Vega et al. 2010). The ubiquitin protease USP7 can deubiquitinate TP53, but in the presence of DAXX deubiquitinates MDM2 (Li et al. 2002, Sheng et al. 2006, Tang et al. 2006). The tumor suppressor p14-ARF, expressed from the CDKN2A gene in response to oncogenic or oxidative stress, forms a tripartite complex with MDM2 and TP53, sequesters MDM2 from TP53, and thus prevents TP53 degradation (Zhang et al. 1998, Parisi et al. 2002, Voncken et al. 2005). For review of this topic, please refer to Kruse and Gu 2009."
BMGC_PW1512,BMG_PW4165,,,"Transcriptional activity of TP53 is positively regulated by acetylation of several of its lysine residues. BRD7 binds TP53 and promotes acetylation of TP53 lysine residue K382 by acetyltransferase EP300 (p300). Acetylation of K382 enhances TP53 binding to target promoters, including CDKN1A (p21), MDM2, SERPINE1, TIGAR, TNFRSF10C and NDRG1 (Bensaad et al. 2010, Burrows et al. 2010. Drost et al. 2010). The histone acetyltransferase KAT6A, in the presence of PML, also acetylates TP53 at K382, and, in addition, acetylates K120 of TP53. KAT6A-mediated acetylation increases transcriptional activation of CDKN1A by TP53 (Rokudai et al. 2013). Acetylation of K382 can be reversed by the action of the NuRD complex, containing the TP53-binding MTA2 subunit, resulting in inhibition of TP53 transcriptional activity (Luo et al. 2000). Acetylation of lysine K120 in the DNA binding domain of TP53 by the MYST family acetyltransferases KAT8 (hMOF) and KAT5 (TIP60) can modulate the decision between cell cycle arrest and apoptosis (Sykes et al. 2006, Tang et al. 2006). Studies with acetylation-defective knock-in mutant mice indicate that lysine acetylation in the p53 DNA binding domain acts in part by uncoupling transactivation and transrepression of gene targets, while retaining ability to modulate energy metabolism and production of reactive oxygen species (ROS) and influencing ferroptosis (Li et al. 2012, Jiang et al. 2015)."
BMGC_PW1513,BMG_PW4166,,,"Association of TP53 (p53) with various transcriptional co-factors can promote, inhibit or provide specificity towards either transcription of cell cycle arrest genes or transcription of cell death genes. Binding of the zinc finger protein ZNF385A (HZF), which is a transcriptional target of TP53, stimulates transcription of cell cycle arrest genes, such as CDKN1A (Das et al. 2007). Binding of POU4F1 (BRN3A) to TP53 also stimulates transcription of cell cycle arrest genes while inhibiting transcription of pro-apoptotic genes (Budhram-Mahadeo et al. 1999, Hudson et al. 2005). Binding of ASPP family proteins PPP1R13B (ASPP1) or TP53BP2 (ASPP2) to TP53 stimulates transcription of pro-apoptotic TP53 targets (Samuels-Lev et al. 2001, Bergamaschi et al. 2004). Binding of the ASPP family member PPP1R13L (iASSP) inhibits TP53-mediated activation of pro-apoptotic genes probably by interfering with binding of stimulatory ASPPs to TP53 (Bergamaschi et al. 2003). Transcription of pro-apoptotic genes is also stimulated by binding of TP53 to POU4F2 (BRN3B) (Budrham-Mahadeo et al. 2006, Budhram-Mahadeo et al. 2014) or to hCAS/CSE1L (Tanaka et al. 2007). Binding of co-factors to TP53 can also affect protein stability. For example, PHF20 binds to TP53 dimethylated on lysine residues K370 and K382 by unidentified protein lysine methyltransferase(s) and interferes with MDM2 binding, resulting in prolonged TP53 half-life (Cui et al. 2012). Long noncoding RNAs can contribute to p53-dependent transcriptional responses (Huarte et al. 2010). For a general review on this topic, see Espinosa 2008, Beckerman and Prives 2010, Murray-Zmijewski et al. 2008, An et al. 2004 and Barsotti and Prives 2010."
BMGC_PW1514,BMG_PW4167,,,"TP53 (p53) undergoes methylation on several lysine and arginine residues, which modulates its transcriptional activity. PRMT5, recruited to TP53 as part of the ATM-activated complex that includes TTC5, JMY and EP300 (p300), methylates TP53 arginine residues R333, R335 and R337. PRMT5-mediated methylation promotes TP53-stimulated expression of cell cycle arrest genes (Shikama et al. 1999, Demonacos et al. 2001, Demonacos et al. 2004, Adams et al. 2008, Adams et al. 2012). SETD9 (SET9) methylates TP53 at lysine residue K372, resulting in increased stability and activity of TP53 (Chuikov et al. 2004, Couture et al. 2006, Bai et al. 2011). TP53 transcriptional activity is repressed by SMYD2-mediated methylation of TP53 at lysine residue K370 (Huang et al. 2006). Dimethylation of TP53 at lysine residue K373 by the complex of methyltransferases EHMT1 and EHMT2 also represses TP53-mediated transcription (Huang et al. 2010). The chromatin compaction factor L3MBTL1 binds TP53 monomethylated at lysine K382 by SETD8 (SET8) and, probably through changing local chromatin architecture, represses transcription of TP53 targets (West et al. 2010). The histone lysine-specific demethylase LSD1 interacts with TP53 and represses p53-mediated transcriptional activation (Huang et al. 2007). PRMT1 and CARM1 can also modulate p53 functions in a cooperative manner (An et al. 2004)."
BMGC_PW1515,BMG_PW4168,,,"Keratins are the major structural protein of vertebrate epidermis, constituting up to 85% of a fully differentiated keratinocyte (Fuchs 1995). Keratins belong to a superfamily of intermediate filament (IF) proteins that form alpha-helical coiled-coil dimers, which associate laterally and end-to-end to form approximately 10 nm diameter filaments. Keratin filaments are heteropolymeric, formed from equal amounts of acidic type I and basic /neutral type 2 keratins. Humans have 54 keratin genes (Schweitzer et al. 2006). They have highly specific expression patterns, related to the epithelial type and stage of differentiation. Roughly half of human keratins are specific to hair follicles (Langbein & Schweizer 2005). Keratin filaments bundle into tonofilaments that span the cytoplasm and bind to desmosomes and other cell membrane structures (Waschke 2008). This reflects their primary function, maintaining the mechanical stability of individual cells and epithelial tissues (Moll et al. 2008)."
BMGC_PW1516,BMG_PW4169,,,"TP53 (p53) tumor suppressor protein is a transcription factor that functions as a homotetramer (Jeffrey et al. 1995). The protein levels of TP53 are low in unstressed cells due to MDM2-mediated ubiquitination that triggers proteasome-mediated degradation of TP53 (Wu et al. 1993). The E3 ubiquitin ligase MDM2 functions as a homodimer/homo-oligomer or a heterodimer/hetero-oligomer with MDM4 (MDMX) (Linares et al. 2003, Toledo and Wahl 2007, Cheng et al. 2011, Wade et al. 2013). Activating phosphorylation of TP53 at serine residues S15 and S20 in response to genotoxic stress disrupts TP53 interaction with MDM2. In contrast to MDM2, E3 ubiquitin ligases RNF34 (CARP1) and RFFL (CARP2) can ubiquitinate phosphorylated TP53 (Yang et al. 2007). Binding of MDM2 to TP53 is also inhibited by the tumor suppressor p14-ARF, transcribed from the CDKN2A gene in response to oncogenic signaling or oxidative stress (Zhang et al. 1998, Parisi et al. 2002, Voncken et al. 2005). Ubiquitin-dependant degradation of TP53 can also be promoted by PIRH2 (Leng et al. 2003) and COP1 (Dornan et al. 2004) ubiquitin ligases. HAUSP (USP7) can deubiquitinate TP53, contributing to TP53 stabilization (Li et al. 2002). While post-translational regulation plays a prominent role, TP53 activity is also controlled at the level of promoter function (reviewed in Saldana-Meyer and Recillas-Targa 2011), mRNA stability and translation efficiency (Mahmoudi et al. 2009, Le et al. 2009, Takagi et al. 2005)."
BMGC_PW1517,BMG_PW4170,,,"Hepatocyte growth factor (HGF), the ligand for MET receptor tyrosine kinase (RTK), is secreted into the extracellular matrix (ECM) as an inactive single chain precursor (pro-HGF). The biologically active HGF is the heterodimer of alpha and beta chains that are produced via proteolytic cleavage of pro-HGF by the plasma membrane bound serine protease Hepsin (HPN) (Kirchhofer et al. 2005, Owen et al. 2010) or the ECM-associated serine protease Hepatocyte growth factor activator (HGFAC, commonly known as HGFA) (Shia et al. 2005). HGF binds to the extracellular SEMA and PSI domains of MET RTK, inducing a conformational change that enables MET dimerization or oligomerization (Kirchhofer et al. 2004, Stamos et al. 2004, Hays and Watowich 2004, Gherardi et al. 2006). MET dimers trans-autophosphorylate on tyrosine residues in the activation loop, leading to increased kinase activity, and on tyrosine residues at the cytoplasmic tail that serve as docking sites for adapter proteins involved in MET signal transduction (Ferracini et al. 1991, Longati et al. 1994, Rodrigues and Park 1994, Ponzetto et al. 1994). CD44v6 was implicated as a MET co-receptor, but its role has been disputed (Orian-Rousseau et al. 2002, Dortet et al. 2010, Olaku et al. 2011, Hasenauer et al. 2013, Elliot et al. 2014)."
BMGC_PW1518,BMG_PW4171,,,"Signaling by MET receptor is negatively regulated mainly by MET receptor dephosphorylation or MET receptor degradation. Protein tyrosine phosphatase PTPRJ dephosphorylates MET tyrosine residue Y1349, thus removing the docking site for the GAB1 adapter (Palka et al. 2003). Protein tyrosine phosphatases PTPN1 and PTPN2 dephosphorylate MET tyrosines Y1234 and Y1235 in the kinase activation loop, thus attenuating catalytic activity of MET (Sangwan et al. 2008). The E3 ubiquitin ligase CBL promotes ubiquitination of the activated MET receptor and subsequent MET degradation. CBL contains a RING finger domain that engages E2 protein ubiquitin ligases to mediate ubiquitination of MET, which may occur at the cell membrane or in the early endocytic compartment. Ubiquitinated MET is degraded in a late endosomal or lysosomal compartment in a proteasome-dependent manner. The involvement of proteasome in MET degradation seems to be indirect, through an effect on MET endocytic trafficking (Jeffers et al. 1997, Peschard et al. 2001, Hammond et al. 2001, Petrelli et al. 2002). LRIG1 promotes lysosome-dependent degradation of MET in the absence of HGF-mediated activation (Lee et al. 2014, Oh et al. 2014). MET-mediated activation of RAS signaling is inhibited by MET receptor binding to MUC20 (Higuchi et al. 2004) or RANBP10 (Wang et al. 2004)."
BMGC_PW1519,BMG_PW4172,,,"The transformation of zymosterol into cholesterol can follow either of routes, one in which reduction of the double bond in the isooctyl side chain is the final step (cholesterol synthesis via desmosterol, also known as the Bloch pathway) and one in which this reduction is the first step (cholesterol biosynthesis via lathosterol, also known as the Kandutsch-Russell pathway). The former pathway is prominent in the liver and many other tissues while the latter is prominent in skin, where it may serve as the source of the 7-dehydrocholesterol that is the starting point for the synthesis of D vitamins (Mitsche et al. 2015)."
BMGC_PW1520,BMG_PW4173,,,"The transformation of zymosterol into cholesterol can follow either of routes, one in which reduction of the double bond in the isooctyl side chain is the final step (cholesterol synthesis via desmosterol, also known as the Bloch pathway) and one in which this reduction is the first step (cholesterol biosynthesis via lathosterol, also known as the Kandutsch-Russell pathway). The former pathway is prominent in the liver and many other tissues while the latter is prominent in skin, where it may serve as the source of the 7-dehydrocholesterol that is the starting point for the synthesis of D vitamins (Kandutsch & Russell 1960; Mitsche et al. 2015)."
BMGC_PW1521,BMG_PW4175,,,"Small nuclear RNAs (snRNAs) play key roles in splicing and some of them, specifically the U1 and U2 snRNAs, are encoded by multicopy snRNA gene clusters containing tandem arrays of genes, about 30 in the RNU1 cluster (Bernstein et al. 1985) and about 10-20 in the RNU2 cluster (Van Ardsell and Weiner 1984). Whereas U6 snRNA genes are transcribed by RNA polymerase III, U1,U2, U4, U4atac, U5, U11, and U12 genes are transcribed by RNA polymerase II. Transcription of the U1 and U2 genes has been most extensively studied and the other snRNA genes as well as other genes with similar promoter structures, for example the SNORD13 gene, are inferred to be transcribed by similar reactions. The snRNA genes transcribed by RNA polymerase II are distinguished from mRNA-encoding genes by the presence of a proximal sequence element (PSE) rather than a TATA box and the presence of the Integrator complex rather than the Mediator complex (reviewed in Egloff et al. 2008, Jawdeker and Henry 2008). The snRNA genes are among the most rapidly transcribed genes in the genome. The 5' transcribed region of the U2 snRNA gene is largely single-stranded during interphase and metaphase (Pavelitz et al. 2008) and chromatin within the transcribed region is cleared of nucleosomes (O'Reilly et al. 2014). Transcriptional activation of the RNA polymerase II transcribed snRNA genes begins with binding of transcription factors to the distal sequence element (DSE) of the promoter (reviewed in Hernandez 2001, Egloff et al. 2008, Jawdeker and Henry 2008). The factors, which include POU2F1 (Oct-1), POU2F2 (Oct-2), ZNF143 (Staf) and Sp1, promote binding of the SNAPc complex (also known as PTF and PBP) to the PSE. SNAPc helps clear the gene of nucleosomes (O'Reilly et al. 2014) and recruits initiation factors (TFIIA, TFIIB, TFIIE, TFIIF, and snTAFc:TBP) which recruit RNA polymerase II. Phosphorylation of the C-terminal domain (CTD) of RNA polymerase II (reviewed in Egloff and Murphy 2008) by CDK7 recruits RPAP2 and the Integrator complex, which is required for later processing of the 3' end of the pre-snRNA transcript (reviewed in Chen and Wagner 2010, Baillat and Wagner 2015). The Little Elongation Complex (LEC) also appears to bind around the time of transcription initiation (Hu et al. 2013). As transcription proceeds, RPAP2 dephosphorylates serine-5 and P-TEFb phosphorylates serine-2 of the CTD. As transcription reaches the end of the snRNA gene serine-7 of the CTD is phosphorylated. These marks serve to bind protein complexes and are required for 3' processing of the pre-snRNA (reviewed in Egloff and Murphy 2008). After transcription proceeds through the conserved 3' processing sequence of the pre-snRNA the Integrator complex cleaves the pre-snRNA. Transcription then terminates downstream in a less well characterized reaction that requires elements of the polyadenylation system."
BMGC_PW1522,BMG_PW4176,,,"The ERGIC (ER-to-Golgi intermediate compartment, also known as vesicular-tubular clusters, VTCs) is a stable, biochemically distinct compartment located adjacent to ER exit sites (Ben-Tekaya et al, 2005; reviewed in Szul and Sztul, 2011). The ERGIC concentrates COPII-derived cargo from the ER for further anterograde transport to the cis-Golgi and also recycles resident ER proteins back to the ER through retrograde traffic. Both of these pathways appear to make use of microtubule-directed COPI-coated vesicles (Pepperkok et al, 1993; Presley et al, 1997; Scales et al, 1997; Stephens and Pepperkok, 2002; Stephens et al, 2000; reviewed in Lord et al, 2001; Spang et al, 2013)."
BMGC_PW1523,BMG_PW4177,,,"As keratinocytes progress towards the upper epidermis, they undergo a unique process of cell death termed cornification (Eckhart et al. 2013). This involves the crosslinking of keratinocyte proteins such as loricrin and involucrin by transglutaminases and the breakdown of the nucleus and other organelles by intracellular and secreted proteases (Eckhart et al. 2000, Denecker et al. 2008). This process is strictly regulated by the Ca2+ concentration gradient in the epidermis (Esholtz et al. 2014). Loricrin and involucrin are encoded in ‘Epidermal Differentiation Complex’ linked to a large number of genes encoding nonredundant components of the CE (Kypriotou et al. 2012, Niehues et al. 2016). Keratinocytes produce specialized proteins and lipids which are used to construct the cornified envelope (CE), a heavily crosslinked submembranous layer that confers rigidity to the upper epidermis, allows keratin filaments to attach to any location in the cell membrane (Kirfel et al. 2003) and acts as a water-impermeable barrier. The CE has two functional parts: covalently cross-linked proteins (10 nm thick) that comprise the backbone of the envelope and covalently linked lipids (5 nm thick) that coat the exterior (Eckert et al. 2005). Desmosomal components are crosslinked to the CE to form corneodesmosomes, which bind cornified cells together (Ishida-Yamamoto et al. 2011). Mature terminally differentiated cornified cells consist mostly of keratin filaments covalently attached to the CE embedded in lipid lamellae (Kalinin et al. 2002). The exact composition of the cornified envelope varies between epithelia (Steinert et al. 1998); the relative amino-acid composition of the proteins used may determine differential mechanical properties (Kartasova et al. 1996)."
BMGC_PW1524,BMG_PW4178,,,"Retrograde traffic from the cis-Golgi to the ERGIC or the ER is mediated in part by microtubule-directed COPI-coated vesicles (Letourneur et al, 1994; Shima et al, 1999; Spang et al, 1998; reviewed in Lord et al, 2013; Spang et al, 2013). These assemble at the cis side of the Golgi in a GBF-dependent fashion and are tethered at the ER by the ER-specific SNAREs and by the conserved NRZ multisubunit tethering complex, known as DSL in yeast (reviewed in Tagaya et al, 2014; Hong and Lev, 2014). Typical cargo of these retrograde vesicles includes 'escaped' ER chaperone proteins, which are recycled back to the ER for reuse by virtue of their interaction with the Golgi localized KDEL receptors (reviewed in Capitani and Sallese, 2009; Cancino et al, 2013)."
BMGC_PW1525,BMG_PW4179,,,"In addition to the better characterized COPI-dependent retrograde Golgi-to-ER pathway, a second COPI-independent pathway has also been identified. This pathway is RAB6 dependent and transports cargo such as glycosylation enzymes and Shiga and Shiga-like toxin through tubular carriers rather than vesicles (White et al, 1999; Girod et al, 1999; reviewed in Heffernan and Simpson, 2014). In the absence of a COPI coat, the membrane curvature necessary to initiate tubulation may be provided through the action of phospholipase A, which hydrolyzes phospholipids at the sn2 position to yield lysophospholipids. This activity is countered by lysophospholipid acyltransferases, and the balance of these may influence whether transport tubules or transport vesicles form (de Figuiredo et al, 1998; reviewed in Bechler et al, 2012). RAB6-dependent tubules also depend on the dynein-dynactin motor complex and the hoomodimeric Bicaudal proteins (Matanis et al, 2002; Yamada et al, 2013; reviewed in Heffernan and Simpson, 2014)."
BMGC_PW1526,BMG_PW4180,,,"The mammalian Golgi consists of at least three biochemically distinct cisternae, cis-, medial- and trans (reviewed in Szul and Sztul, 2011; Day et al, 2013). The structure and function of the Golgi are tightly interconnected, such that proteins that are required for protein transport through the Golgi are often also required for the organization of the Golgi stacks, and vice versa (reviewed in Liu and Storrie, 2012; Liu and Storrie, 2015; Chia and Gleeson, 2014; Munro, 2011). Newly synthesized proteins from the ER and ERGIC are received at the cis face of the Golgi and flow through to the trans-Golgi before being released to the trans-Golgi network (TGN) for further secretion to the endolysosomal system, plasma membrane or extracellular region. Retrograde flow from the trans- to cis-cisternae moves endocytosed cargo from the extracellular region, the plasma membrane and the endolysosomal system back towards the ER. Intra-Golgi retrograde traffic also returns resident Golgi proteins to their appropriate cisternae, in this way facilitating cisternal remodeling or maturation (reviewed in Boncompain and Perez, 2013; Day et al, 2013). Intra-Golgi traffic in both directions is mediated by COPI carriers, with specificity of transport being determined at least in part by the complement of SNAREs, RABs and tethering proteins involved (reviewed in Szul and Sztul, 2011; Spang 2013; Willet et al, 2013; Chia and Gleeson, 2014)."
BMGC_PW1527,BMG_PW4181,,,"The trans-Golgi network is the docking site for retrograde cargo from the endolysosomal system and the plasma membrane. Typical cargo includes recycling resident TGN proteins such as TGOLN2 (also known as TGN46), receptors such as the mannose-6-phosphate receptors and toxins like Shiga, cholera and ricin which use the retrograde trafficking machinery to 'hitchhike' back through the secretory system for release into the cytoplasm (reviewed in Johannes and Popoff, 2008; Pfeffer, 2011; Sandvig et al, 2013). These cargo are trafficked from the endocytic system in a clathrin- and AP1-dependent manner that is described in more detail in the ""Trans-Golgi network budding pathway"" (just not yet). In general, it appears that vesicles are uncoated prior to their tethering and fusion at the TGN. At the TGN, at least 2 distinct tethering pathways exist. A RAB6-dependent pathway contributes to the fusion and docking of vesicles from the early endocytic pathway. These vesicles, which carry cargo such as TGOLN2 and toxins, dock at the TGN through interactions with TGN-localized Golgin tethers and with the multisubunit tethering complexes COG and GARP (reviewed in Bonafacino and Rojas, 2006; Bonafacino and Hierro, 2011; Pfeffer, 2011). In contrast, mannose-6-phosphate receptors appear to traffic from late endosomes to the TGN through a RAB9- and PLIN3-dependent pathway. Vesicles are recruited to the TGN through interaction of RAB9 with the atypical RHO GTPase RHOBTB3, and tethered by virtue of interaction with TGN-localized Golgins and the GARP complex (Perez-Victoria et al, 2008; Perez-Victoria et al, 2009; Diaz et al, 1999; reviewed in Pfeffer, 2011; Chia and Gleeson, 2014)"
BMGC_PW1528,BMG_PW4182,,,"The mammalian Golgi complex, a central hub of both anterograde and retrograde trafficking, is a ribbon of stacked cisterna with biochemically distinct compartments (reviewed in Glick and Nakano, 2009; Szul and Sztul, 2011). Anterograde cargo from the ERGIC and ER is received at the cis-Golgi, trafficked through the medial- and trans-Golgi and released through the trans-Golgi network (TGN) to the endolysosomal system and the plasma membrane. Although still under debate, current models of Golgi trafficking favour the cisternal maturation model, where anterograde cargo remain associated with their original lipid membrane during transit through the Golgi and are exposed to sequential waves of processing enzymes by the retrograde movement of Golgi resident proteins. In this way, cis-cisterna mature to medial- and trans-cisterna as the early acting Golgi enzymes are replaced by later acting ones (reviewed in Pelham, 2001; Storrie, 2005; Glick and Nakano, 2009; Szul and Sztul, 2011). More recently. a kiss-and-run (KAR) model for intra-Golgi trafficking has been proposed, which marries aspects of the cisternal maturation model with a diffusion model of transport (reviewed in Mironov et al, 2103). Like the anterograde ERGIC-to Golgi transport step, intra-Golgi trafficking between the cisterna appears to be COPI-dependent (Storrie and Nilsson, 2002; Szul and Sztul, 2011). Numerous snares and tethering complexes contribute to the targeting and fusion events that are required to maintain the specificity and directionality of these trafficking events (reviewed in Chia and Gleeson, 2014). Golgi tethers include long coiled coiled proteins like the Golgins, as well as multisubunit tethers like the COG complex. These tethers make numerous interactions with other components of the secretory system including RABs, SNAREs, motor and coat proteins as well as components of the cytoskeleton (reviewed in Munro, 2011; Willet et al, 2013). Retrograde traffic from the cis-Golgi back to the ERGIC and ER depends on both the COPI-dependent pathway, which appears to be important for recyling of KDEL receptors, and a more recently described COPI-independent pathway that relies on RAB6 (reviewed in Szul and Sztul, 2011; Heffernan and Simpson, 2014). RAB6 and RAB9 also play roles at the TGN side of the Golgi, where they are implicated in the docking of vesicles derived from the endolysosomal system and the plasma membrane (reviewed in Pfeffer, 2011)"
BMGC_PW1529,BMG_PW4183,,,"Under conditions of cellular stress, nuclear levels of phosphatidylinositol-5-phosphate (PI5P) increase and, through interaction with ING2, result in nuclear retention/accumulation of ING2. ING2 binds TP53 (p53) and recruits histone acetyltransferase EP300 (p300) to TP53, leading to TP53 acetylation. Increased nuclear PI5P levels positively regulate TP53 acetylation (Ciruela et al. 2000, Gozani et al. 2003, Jones et al. 2006, Zou et al. 2007, Bultsma et al. 2010)."
BMGC_PW1530,BMG_PW4184,,,"Phosphatidylinositol-5-phosphate (PI5P) may modulate PI3K/AKT signaling in several ways. PI5P is used as a substrate for production of phosphatidylinositol-4,5-bisphosphate, PI(4,5)P2 (Rameh et al. 1997, Clarke et al. 2008, Clarke et al. 2010, Clarke and Irvine 2013, Clarke et al. 2015), which serves as a substrate for activated PI3K, resulting in the production of PIP3 (Mandelker et al. 2009, Burke et al. 2011). The majority of PI(4,5)P2 in the cell, however, is produced from the phosphatidylinositol-4-phosphate (PI4P) substrate (Zhang et al. 1997, Di Paolo et al. 2002, Oude Weernink et al. 2004, Halstead et al. 2006, Oude Weernink et al. 2007). PIP3 is necessary for the activating phosphorylation of AKT. AKT1 can be deactivated by the protein phosphatase 2A (PP2A) complex that contains a regulatory subunit B56-beta (PPP2R5B) or B56-gamma (PPP2R5C). PI5P inhibits AKT1 dephosphorylation by PP2A through an unknown mechanism (Ramel et al. 2009). Increased PI5P levels correlate with inhibitory phosphorylation(s) of the PP2A complex. MAPK1 (ERK2) and MAPK3 (ERK1) are involved in inhibitory phosphorylation of PP2A, in a process that involves IER3 (IEX-1) (Letourneux et al. 2006, Rocher et al. 2007). It is uncertain, however, whether PI5P is in any way involved in ERK-mediated phosphorylation of PP2A or if it regulates another PP2A kinase."
BMGC_PW1531,BMG_PW4185,,,"The chaperonin complex TRiC/CCT is needed for the proper folding of all five G-protein beta subunits (Wells et al. 2006). TRiC/CCT cooperates with the phosducin-like protein PDCL (commonly known as PhLP or PhLP1), which interacts with both TRiC/CCT and G-protein beta subunits 1-5 (GNB1, GNB2, GNB3, GNB4, GNB5) (Dupre et al. 2007, Howlett et al. 2009). PDCL enables completion of G-protein beta folding by TRiC/CCT, promotes release of folded G-protein beta subunits 1-4 (GNB1, GNB2, GNB3, GNB4) from the chaperonin complex, and facilitates the formation of the heterodimeric G-protein beta:gamma complex between G-protein beta subunits 1-4 and G-protein gamma subunits 1-12 (Lukov et al. 2005, Lukov et al. 2006, Howlett et al. 2009, Lai et al. 2013, Plimpton et al. 2015, Xie et al. 2015). In the case of G-protein beta 5 (GNB5), PDCL stabilizes the interaction of GNB5 with the TRiC/CCT and promotes GNB5 folding, thus positively affecting formation of GNB5 dimers with RGS family proteins (Howlett et al. 2009, Lai et al. 2013, Tracy et al. 2015). However, over-expression of PDCL interferes with formation of GNB5:RGS dimers as PDCL and RGS proteins bind to the same regions of the GNB5 protein (Howlett et al. 2009)."
BMGC_PW1532,BMG_PW4186,,,"Human ORC1 can associate with DNA origin of replication sites independently of other origin of replication complex (ORC) subunits (Hoshina et al. 2013; Eladl et al. 2021). ORC1 localizes to condensed chromosomes during early mitosis (M phase) and serves as a nucleating center for the assembly of the ORC and, subsequently, the pre-replication complex. ORC1 remains associated with late replication origins throughout late G1. Upon S phase entry, ORC1 undergoes ubiquitin-mediated degradation, leading to dissociation of the ORC from chromatin (Kara et al. 2015). Most human replication origins contain guanine (G)-rich sequences which may form G-quadruplex (G4) structures (Besnard et al. 2012) and these G4 structures may mediate the recognition of replication origins by ORC1 (Hoshina et al. 2013; Eladl et al. 2021). Besides binding to nucleosome-free replication origin DNA, ORC1 interacts with neighboring nucleosomes (Hizume et al. 2013), in particular with nucleosomes containing histone H4 dimethylated at lysine 21 (H4K20me2 mark), which is enriched at replication origins. Binding of ORC1 to H4K20me2 facilitates ORC1 binding to replication origins and ORC chromatin loading (Kuo et al. 2012, Zhang et al. 2015). ORC1 binding sites are universally associated with transcription start sites (TSSs) of coding and non-coding RNAs. Replication origins associated with moderate to high transcription level TSSs (belonging to coding RNAs) fire in early S phase, while those associated with low transcription level TSSs (belonging to non-coding RNAs) fire throughout the S phase (Dellino et al. 2013). ORC2 forms a heterodimer with ORC3, which is a prerequisite for the association of ORC5 and, subsequently, ORC4 (Ranjan and Gossen 2006; Siddiqui and Stillman 2007). ORC1 binds to the ORC(2-5) complex in the nucleus to form a stable ORC(1-5) complex (Radichev et al. 2006; Ghosh et al. 2011). ORC1 is necessary for the association of the ORC(2-5) complex to chromatin (Radichev et al. 2006). The ORC(2-5) complex exhibits a tightly autoinhibited conformation, with the winged-helix domain (WHD) of ORC2 completely blocking the central DNA-binding channel. Binding of ORC1 remodels the WHD of ORC2, moving it away from the central channel and partially relieving the autoinhibition (Cheng et al. 2020, Jaremko et al. 2020). ORC6 associates with the ORC(1-5) complex to form the ORC(1-6) complex (Ghosh et al. 2011). The association of ORC6 with the ORC(1-5) complex is weak and it frequently does not co-immunoprecipitate with the other ORC(1-5) subunits. ORC4 is the only ORC(1-5) subunit that was shown to directly bind to ORC6 (Radichev et al. 2006). Some ORC6 mutations reported in Meier-Gorlin syndrome were shown to interfere with ORC6 incorporation into the ORC (Balasov et al. 2015)."
BMGC_PW1533,BMG_PW4187,,,"Cdc6 is a regulator of DNA replication initiation in both yeasts and human cells (Mendez and Stillman 2000), but its mechanism of action differs between the two systems. Genetic studies in budding yeast (S. cerevisiae) and fission yeast (S. pombe) indicate that the normal function of Cdc6 protein is required to restrict DNA replication to once per cell cycle. Specifically, Cdc6 may function as an ATPase switch linked to Mcm2-7:Cdt1 association with the Cdc6:ORC:origin complex (Lee and Bell 2000). In S. cerevisiae, Cdc6 protein is expressed late in the M phase of the cell cycle and, in cells with a prolonged G1 phase, late in G1. This protein has a short half-life, and is destroyed by ubiquitin-mediated proteolysis, mediated by the SCF complex (Piatti et al. 1995, Drury et al. 1997, Drury et al. 2000, Perkins et al. 2001). Human Cdc6 protein levels are reduced early in G1 but otherwise are constant throughout the cell cycle (Petersen et al. 2000). Some reports have suggested that after cells enter S phase, Cdc6 is phosphorylated, excluded from the nucleus and subject to ubiquitination and degradation (Saha et al. 1998, Jiang et al. 1999, Petersen et al. 1999). Replenishing Cdc6 protein levels during G1 appears to be regulated by E2F transcription factors (Yan et al. 1998)."
BMGC_PW1534,BMG_PW4188,,,"DNA replication pre-initiation in eukaryotic cells begins with the formation of the pre-replicative complex (pre-RC) during the late M phase and continues in the G1 phase of the mitotic cell cycle, a process also called DNA replication origin licensing. The association of initiation proteins (ORC, Cdc6, Cdt1, Mcm2-7) with the origin of replication in both S. cerevisiae and humans has been demonstrated by chromatin immunoprecipitation experiments. In S. cerevisiae, pre-replicative complexes are assembled from late M to G1. In mammalian cells as well, pre-replicative complexes are assembled from late M to G1, as shown by biochemical fractionation and immunostaining. There are significant sequence similarities among some of the proteins in the pre-replicative complex. The ORC subunits Orc1, Orc4 and Orc5 are homologous to one another and to Cdc6. The six subunits of the Mcm2-7 complex are homologous to one another. In addition, Orc1, Orc4, Orc5, Cdc6, and the Mcm2-7 subunits, are members of the AAA+ superfamily of ATPases. Since the initial identification of these pre-RC components other factors that participate in this complex have been found, including Cdt1 in human, Xenopus, S. pombe, and S. cerevisiae cells."
BMGC_PW1535,BMG_PW4189,,,"During prophase, the chromatin in the nucleus condenses, and the nucleolus disappears. Centrioles begin moving to the opposite poles or sides of the cell. Some of the fibers that extend from the centromeres cross the cell to form the mitotic spindle."
BMGC_PW1536,BMG_PW4190,,,"The dissolution of the nuclear membrane marks the beginning of the prometaphase. Kinetochores are created when proteins attach to the centromeres. Microtubules then attach at the kinetochores, and the chromosomes begin to move to the metaphase plate."
BMGC_PW1537,BMG_PW4192,,,"In this final phase of mitosis, new membranes are formed around two sets of chromatids and two daughter cells are formed. The chromosomes and the spindle fibers disperse, and the fiber ring around the center of the cell, composed of actin, contracts, pinching the cell into two daughter cells."
BMGC_PW1538,BMG_PW4193,,,Mammalian Orc1 protein is phosphorylated and selectively released from chromatin and ubiquitinated during the S-to-M transition in the cell division cycle.
BMGC_PW1539,BMG_PW4194,,,"In S. cerevisiae, two ORC subunits, Orc1 and Orc5, both bind ATP, and Orc1 in addition has ATPase activity. Both ATP binding and ATP hydrolysis appear to be essential functions in vivo. ATP binding by Orc1 is unaffected by the association of ORC with origin DNA (ARS) sequences, but ATP hydrolysis is ARS-dependent, being suppressed by associated double-stranded DNA and stimulated by associated single-stranded DNA. These data are consistent with the hypothesis that ORC functions as an ATPase switch, hydrolyzing bound ATP and changing state as DNA unwinds at the origin immediately before replication. It is attractive to speculate that ORC likewise functions as a switch as human pre-replicative complexes are activated, but human Orc proteins are not well enough characterized to allow the model to be critically tested. mRNAs encoding human orthologs of all six Orc proteins have been cloned, and ATP-binding amino acid sequence motifs have been identified in Orc1, Orc4, and Orc5. Interactions among proteins expressed from the cloned genes have been characterized, but the ATP-binding and hydrolyzing properties of these proteins and complexes of them have not been determined."
BMGC_PW1540,BMG_PW4195,,,"Although, DNA replication occurs in the S phase of the cell cycle, the formation of the DNA replication pre-initiation complex begins during G1 phase."
BMGC_PW1541,BMG_PW4196,,,"As cells enter S phase, HsCdc6p is phosphorylated by CDK promoting its export from the nucleus (see Bell and Dutta 2002)."
BMGC_PW1542,BMG_PW4197,,,"Switching of origins to a post-replicative state involves the removal of Orc1 from chromatin, CDK-mediated phosphorylation and removal of Cdc6, and the rearrangement and mobilization of Mcm2-7."
BMGC_PW1543,BMG_PW4198,,,"After the primers are synthesized, Replication Factor C binds to the 3'-end of the initiator DNA to trigger polymerase switching. The non-processive nature of pol alpha catalytic activity and the tight binding of Replication Factor C to the primer-template junction presumably lead to the turnover of the pol alpha:primase complex. After the Pol alpha-primase primase complex is displaced from the primer, the proliferating cell nuclear antigen (PCNA) binds to form a ""sliding clamp"" structure. Replication Factor C then dissociates, and DNA polymerase delta binds and catalyzes the processive synthesis of DNA."
BMGC_PW1544,BMG_PW4199,,,"The processive complex is responsible for synthesizing at least 5-10 kb of DNA in a continuous manner during leading strand synthesis. The incorporation of nucleotides by pol delta is quite accurate. However, incorporation of an incorrect nucleotide does occur occasionally. Misincorporated nucleotides are removed by the 3' to 5' exonucleolytic proofreading capability of pol delta."
BMGC_PW1545,BMG_PW4200,,,"Two endonucleases, Dna2 and flap endonuclease 1 (FEN-1), are responsible for resolving the nascent flap structure (Tsurimoto and Stillman 1991). The Dna2 endonuclease/helicase in yeast is a monomer of approximately 172 kDa. Human FEN-1 is a single polypeptide of approximately 42 kDa. Replication Protein A regulates the switching of endonucleases during the removal of the displaced flap (Tsurimoto et al.1991)."
BMGC_PW1546,BMG_PW4201,,,"The key event that allows the processive synthesis on the lagging strand, is polymerase switching from pol alpha to pol delta, as on the leading strand. However, the processive synthesis on the lagging strand proceeds very differently. DNA synthesis is discontinuous, and involves the formation of short fragments called the Okazaki fragments. During the synthesis of Okazaki fragments, the RNA primer is folded into a single-stranded flap, which is removed by endonucleases. This is followed by the ligation of adjacent Okazaki fragments."
BMGC_PW1547,BMG_PW4202,,,"Due to the antiparallel nature of DNA, DNA polymerization is unidirectional, and one strand is synthesized discontinuously. This strand is called the lagging strand. Although the polymerase switching on the lagging strand is very similar to that on the leading strand, the processive synthesis on the two strands proceeds quite differently. Short DNA fragments, about 100 bases long, called Okazaki fragments are synthesized on the RNA-DNA primers first. Strand-displacement synthesis occurs, whereby the primer-containing 5'-terminus of the adjacent Okazaki fragment is folded into a single-stranded flap structure. This flap structure is removed by endonucleases, and the adjacent Okazaki fragments are joined by DNA ligase."
BMGC_PW1548,BMG_PW4203,,,The G1/S transition is facilitated by Cyclin E:Cdk2-mediated phoshorylation of proteins including Rb and Cyclin Kinase Inhibitors (CKIs).
BMGC_PW1549,BMG_PW4204,,,"The transition from the G1 to S phase is controlled by the Cyclin E:Cdk2 complexes. As the Cyclin E:Cdk2 complexes are formed, the Cdk2 is phosphorylated by the Wee1 and Myt1 kinases. This phosphorylation keeps the Cdk2 inactive. In yeast this control is called the cell size checkpoint control. The dephosphorylation of the Cdk2 by Cdc25A activates the Cdk2, and is coordinated with the cells reaching the proper size, and with the DNA synthesis machinery being ready. The Cdk2 then phosphorylates G1/S specific proteins, including proteins required for DNA replication initiation. The beginning of S-phase is marked by the first nucleotide being laid down on the primer during DNA replication at the early-firing origins.Failure to appropriately regulate cyclin E accumulation can lead to accelerated S phase entry, genetic instability, and tumorigenesis. The amount of cyclin E protein in the cell is controlled by ubiquitin-mediated proteolysis (see Woo, 2003).This pathway has not yet been annotated in Reactome."
BMGC_PW1550,BMG_PW4205,,,"The E2F family of transcription factors regulate the transition from the G1 to the S phase in the cell cycle. E2F activity is regulated by members of the retinoblastoma protein (pRb) family, resulting in the tight control of the expression of E2F-responsive genes. Phosphorylation of pRb by cyclin D:CDK complexes releases pRb from E2F, inducing E2F-targeted genes such as cyclin E. E2F1 binds to E2F binding sites on the genome activating the synthesis of the target proteins. For annotation purposes, the reactions regulated by E2F1 are grouped under this pathway and information about the target genes alone are displayed for annotation purposes. Cellular targets for activation by E2F1 include thymidylate synthase (TYMS) (DeGregori et al. 1995), Rir2 (RRM2) (DeGregori et al. 1995, Giangrande et al. 2004), Dihydrofolate reductase (DHFR) (DeGregori et al. 1995, Wells et al. 1997, Darbinian et al. 1999), Cdc2 (CDK1) (Furukawa et al. 1994, DeGregori et al. 1995, Zhu et al. 2004), Cyclin A1 (CCNA1) (DeGregori et al. 1995, Liu et al. 1998), CDC6 (DeGregori et al. 1995, Yan et al. 1998; Ohtani et al. 1998), CDT1 (Yoshida and Inoue 2004), CDC45 (Arata et al. 2000), Cyclin E (CCNE1) (Ohtani et al. 1995), Emi1 (FBXO5) (Hsu et al. 2002), and ORC1 (Ohtani et al. 1996, Ohtani et al. 1998). The activation of TK1 (Dnk1) (Dou et al. 1994, DeGregori et al. 1995, Giangrande et al. 2004) and CDC25A (DeGregori et al. 1995, Vigo et al. 1999) by E2F1 is conserved in Drosophila (Duronio and O'Farrell 1994, Reis and Edgar 2004). RRM2 protein is involved in dNTP level regulation and activation of this enzyme results in higher levels of dNTPs in anticipation of S phase. E2F activation of RRM2 has been shown also in Drosophila by Duronio and O'Farrell (1994). E2F1 activation of CDC45 is shown in mouse cells by using human E2F1 construct (Arata et al. 2000). Cyclin E is also transcriptionally regulated by E2F1. Cyclin E protein plays important role in the transition of G1 in S phase by associating with CDK2 (Ohtani et al. 1996). E2F1-mediated activation of PCNA has been demonstrated in Drosophila (Duronio and O'Farrell 1994) and in some human cells by using recombinant adenovirus constructs (DeGregori et al. 1995). E2F1-mediated activation of the DNA polymerase alpha subunit p180 (POLA1) has been demonstrated in some human cells. It has also been demonstrated in Drosophila by Ohtani and Nevins (1994). It has been observed in Drosophila that E2F1 induced expression of Orc1 stimulates ORC1 6 complex formation and binding to the origin of replication (Asano and Wharton 1999). ORC1 6 recruit CDC6 and CDT1 that are required to recruit the MCM2 7 replication helicases. E2F1 regulation incorporates a feedback mechanism wherein Geminin (GMNN) can inhibit MCM2 7 recruitment of ORC1 6 complex by interacting with CDC6/CDT1. The activation of CDC25A and TK1 (Dnk1) by E2F1 has been inferred from similar events in Drosophila (Duronio RJ and O'Farrell 1994; Reis and Edgar 2004). E2F1 activates string (CDC25) that in turn activates the complex of Cyclin B and CDK1. A similar phenomenon has been observed in mouse NIH 3T3 cells and in Rat1 cells."
BMGC_PW1551,BMG_PW4206,,,"Three D-type cyclins are essential for progression from G1 to S-phase. These D cyclins bind to and activate both CDK4 and CDK6. The formation of all possible complexes between the D-type cyclins and CDK4/6 is promoted by the proteins, p21(CIP1/WAF1) and p27(KIP1). The cyclin-dependent kinases are then activated due to phosphorylation by CAK. The cyclin dependent kinases phosphorylate the RB1 protein and RB1-related proteins p107 (RBL1) and p130 (RBL2). Phosphorylation of RB1 leads to release of activating E2F transcription factors (E2F1, E2F2 and E2F3). After repressor E2Fs (E2F4 and E2F5) dissociate from phosphorylated RBL1 and RBL2, activating E2Fs bind to E2F promoter sites, stimulating transcription of cell cycle genes, which then results in proper G1/S transition. The binding and sequestration of p27Kip may also contribute to the activation of CDK2 cyclin E/CDK2 cyclin A complexes at the G1/S transition (Yew et al., 2001)."
BMGC_PW1552,BMG_PW4207,,,"Cell cycle progression is regulated by cyclin-dependent protein kinases at both the G1/S and the G2/M transitions. The G2/M transition is regulated through the phosphorylation of nuclear lamins and histones (reviewed in Sefton, 2001). The two B-type cyclins localize to different regions within the cell and are thought to have specific roles as CDK1-activating subunits (see Bellanger et al., 2007). Cyclin B1 is primarily cytoplasmic during interphase and translocates into the nucleus at the onset of mitosis (Jackman et al., 1995; Hagting et al., 1999). Cyclin B2 colocalizes with the Golgi apparatus and contributes to its fragmentation during mitosis (Jackman et al., 1995; Draviam et al., 2001)."
BMGC_PW1553,BMG_PW4208,,,Procaspase-8 monomers undergo dimerization. The dimerization event occurs at death-inducing signaling complex (DISC) and results in a reposition of the procaspase-8 inter-subunit linker to become accessible for intermolecular processing by the associated procaspase-8 molecule [Keller N et al 2010; Oberst A et al 2010].
BMGC_PW1554,BMG_PW4209,,,"Later studies pin-pointed that a single serine (Ser-15) was phosphorylated by ATM and phosphorylation of Ser-15 was rapidly-induced in IR-treated cells and this response was ATM-dependent (Canman et al, 1998; Banin et al, 1998 and Khanna et al, 1998). ATM also regulates the phosphorylation of p53 at other sites, especially Ser-20, by activating other serine/threonine kinases in response to IR (Chehab et al, 2000; Shieh et al, 2000; Hirao et al 2000). Phosphorylation of p53 at Ser-20 interferes with p53-MDM2 interaction. MDM2 is transcriptionally activated by p53 and is a negative regulator of p53 that targets it for degradation (Haupt et al, 1997; Kubbutat et al, 1997). In addition modification of MDM2 by ATM also affects p53 stabilization (Maya et al, 2001)."
BMGC_PW1555,BMG_PW4210,,,"p53 causes G1 arrest by inducing the expression of a cell cycle inhibitor, p21 (El-Deiry et al, 1993; Harper et al, 1993; Xiong et al, 1993). P21 binds and inactivates Cyclin-Cdk complexes that mediate G1/S progression, resulting in lack of phosphorylation of Rb, E2F sequestration and cell cycle arrest at the G1/S transition. Mice with a homozygous deletion of p21 gene are deficient in their ability to undergo a G1/S arrest in response to DNA damage (Deng et al, 1995)."
BMGC_PW1556,BMG_PW4211,,,"Most of the damage-induced modifications of p53 are dependent on the ATM kinase. The first link between ATM and p53 was predicted based on the earlier studies that showed that AT cells exhibit a reduced and delayed induction of p53 following exposure to IR (Kastan et al, 1992 and Khanna and Lavin, 1993). Under normal conditions, p53 is a short-lived protein. The MDM2 protein, usually interacts with p53 (Haupt et al, 1997 and Kubbutat et al, 1997), and by virtue of its E3 ubiquitin ligase activity, shuttles p53 to the cytoplasm and mediates its degradation by the ubiquitin-proteasome machinery. Upon detection of DNA damage, the ATM kinase mediates the phosphorylation of the Mdm2 protein to block its interaction with p53. Also, phosphorylation of p53 at multiple loci, by the ATM kinase and by other kinases activated by the ATM kinase, stabilizes and activates the p53 protein. The p53 protein activates the transcription of cyclin-dependent kinase inhibitor, p21. p21 inactivates the CyclinE:Cdk2 complexes, and prevent entry of the cell into S phase, leading to G1 arrest. Under severe conditions, the cell may undergo apoptosis."
BMGC_PW1557,BMG_PW4212,,,cdc25A protein is degraded by the ubiquitin-proteasome machinery in both terminally differentiating and cycling cells (Bernardi et al. 2000).
BMGC_PW1558,BMG_PW4213,,,"In response to DNA damage due to exposure to ultraviolet light or to ionizing radiation, Cdc25A is phosphorylated by Chk1 or Chk2. The phosphorylation of Cdc25A at ser-123, in response to DNA damage from ionizing radiation is a signal for ubiquitination and subsequent degradation of Cdc25A. The destruction of Cdc25A prevents the normal G1/S transition. Cdc25A is required for the activation of the Cyclin E:Cdk2 complexes via dephosphorylation. Chk1 is activated in response to DNA damage due to uv light. However, the phosphorylation occurs at a different site."
BMGC_PW1559,BMG_PW4214,,,"The G1 arrest induced by DNA damage has been ascribed to the transcription factor and tumor suppressor protein p53. To be effective within minutes after DNA damage, induction of the G1 block should exploit transcription and protein synthesis independent mechanisms. Upon exposure to ultraviolet light (UV) or ionizing radiation (IR), the abundance and activity of a protein, Cdc25A, rapidly decreases; this DNA damage response is not dependent on p53. The rapid destruction of Cdc25A phosphatase prevents entry of a cell into S-phase, by maintaining the CyclinE:Cdk2 complexes in their T14Y15 phosphorylated form."
BMGC_PW1560,BMG_PW4215,,,"Cyclin A:Cdk2 plays a key role in S phase entry by phosphorylation of proteins including Cdh1, Rb, p21 and p27. During G1 phase of the cell cycle, cyclin A is synthesized and associates with Cdk2. After forming in the cytoplasm, the Cyclin A:Cdk2 complexes are translocated to the nucleus (Jackman et al.,2002). Prior to S phase entry, the activity of Cyclin A:Cdk2 complexes is negatively regulated through Tyr 15 phosphorylation of Cdk2 (Gu et al., 1995) and also by the association of the cyclin kinase inhibitors (CKIs), p27 and p21. Phosphorylation of cyclin-dependent kinases (CDKs) by the CDK-activating kinase (CAK) is required for the activation of the CDK2 kinase activity (Aprelikova et al., 1995). The entry into S phase is promoted by the removal of inhibitory Tyr 15 phosphates from the Cdk2 subunit of Cyclin A:Cdk2 complex by the Cdc25 phosphatases (Blomberg and Hoffmann, 1999) and by SCF(Skp2)-mediated degradation of p27/p21 (see Ganoth et al., 2001). While Cdk2 is thought to play a primary role in regulating entry into S phase, recent evidence indicates that Cdk1 is equally capable of promoting entry into S phase and the initiation of DNA replication (see Bashir and Pagano, 2005). Thus, Cdk1 complexes may also play a significant role at this point in the cell cycle."
BMGC_PW1561,BMG_PW4216,,,"Both p53-independent and p53-dependent mechanisms of induction of p21 mRNA have been demonstrated. p21 is transcriptionally activated by p53 after DNA damage (el-Deiry et al., 1993)."
BMGC_PW1562,BMG_PW4217,,,"Propionyl-CoA is a product of the catabolism of the amino acids, leucine, methionine, and threonine, and of the beta-oxidation of fatty acids with odd numbers of carbon atoms. The three reactions of this pathway convert propionyl-CoA to succinyl-CoA, an intermediate of the citric acid cycle. Through these reactions, carbon atoms from these sources can be fully oxidized to produce energy, or can be directed to gluconeogenesis. The three reactions of propionyl-CoA catabolism take place in the mitochondrial matrix."
BMGC_PW1563,BMG_PW4218,,,"Cellular metabolism of amino acids and related molecules includes the pathways for the catabolism of amino acids, the biosynthesis of the nonessential amino acids (alanine, arginine, aspartate, asparagine, cysteine, glutamate, glutamine, glycine, proline, and serine) and selenocysteine, the synthesis of urea, and the metabolism of carnitine, creatine, choline, polyamides, melanin, and amine-derived hormones. The metabolism of amino acids provides a balanced supply of amino acids for protein synthesis. In the fasting state, the catabolism of amino acids derived from breakdown of skeletal muscle protein and other sources is coupled to the processes of gluconeogenesis and ketogenesis to meet the body’s energy needs in the absence of dietary energy sources. These metabolic processes also provide the nitrogen atoms for the biosynthesis of nucleotides and heme, annotated as separate metabolic processes (Felig 1975; Häussinger 1990; Owen et al. 1979). Transport of these molecuels across lipid bilayer membranes is annotated separately as part of the module on ""transmembrane transport of small molecules""."
BMGC_PW1564,BMG_PW4220,,,"The 5'-ends of all eukaryotic pre-mRNAs studied thus far are converted to cap structures. The cap is thought to influence splicing of the first intron, and is bound by 'cap-binding' proteins, CBP80 and CBP20, in the nucleus. The cap is important for translation initiation, and it also interacts with the poly(A)terminus, via proteins, resulting in circularization of the mRNA to facilitate multiple rounds of translation. The cap is also important for mRNA stability, protecting it from 5' to 3' nucleases, and is required for mRNA export to the cytoplasm. The capping reaction usually occurs very rapidly on nascent transcripts; after the synthesis of only a few nucleotides by RNA polymerase II. The capping reaction involves the conversion of the 5'-end of the nascent transcript from a triphosphate to a diphosphate by a RNA 5'-triphosphatase, followed by the addition of a guanosine monophosphate by the mRNA guanylyltransferase, to form a 5'-5'-triphosphate linkage. This cap is then methylated by 2'-O-methyltransferases."
BMGC_PW1565,BMG_PW4221,,,"Eukaryotic genes are transcribed to yield pre-mRNAs that are processed to add methyl guanosine cap structures and polyadenylate tails and to splice together segments of a pre-mRNA termed exons, thereby removing segments termed introns. More than 90% of human genes contain introns, with an average of 4.0 introns per gene and 3413 nucleotides per intron compared with 5.0 exons per gene and 50.9 nucleotides per exon (Deutsch and Long 1999). (Notable exceptions are the histone genes, which are intronless.) Pre-mRNA splicing is performed by a large ribonucleoprotein complex, the spliceosome, which contains 5 small nuclear RNAs (snRNAs) and more than 150 proteins (reviewed in Will and Luhrmann 2011, Kastner et al. 2019, Yan et al. 2019, Fica et al. 2020, Wan et al. 2020, Wilkinson et al. 2020). The catalyst in the spliceosome comprises magnesium ions coordinated by the U6 snRNA that catalyze transesterification reactions between hydroxyl groups and phosphate groups from the pre-mRNA. The role of the U6 snRNA demonstrates that the spliceosome is a ribozyme hints at the origin of the spliceosome as a self-splicing group II intron. The spliceosome is initially assembled cotranscriptionally on the pre-mRNA as the Spliceosomal E (Early) complex and then remodelled sequentially by association and dissociation of proteins and snRNAs to catalyze of the two reactions of splicing. First, a nucleophilic attack by the 2' hydroxyl group of a conserved adenine residue, the branch point, within the intron on the phosphate group of the 5' residue of the intron yields a lariat (looped) structure in the intron joined to the downstream (3') exon and a free upstream exon with a 3' hydroxyl group. Second, a nucleophilic attack by the 3' hydroxyl group of the upstream exon on the phosphate of the 5' residue of the downstream exon yields a spliced mRNA containing the upstream exon ligated to the downstream exon and a free intron containing a lariat structure. The Spliceosomal E complex contains the U1 snRNP bound to the 5' splice site, SF1 bound to the branch point, and the U2AF complex bound to the polypyrimidine tract of the intron and the 3' splice site of the pre-mRNA (Zhuang and Weiner 1986, Hong et al. 1997, Das et al. 2000, Hartmuth et al. 2002, Rappsilber et al. 2002, Hegele et al. 2012, Makarov et al. 2012, Crisci et al. 2015, Kondo et al. 2015, Tan et al. 2016). SF1 and U2AF are displaced on the pre-mRNA and the U2 snRNP binds the branch region to yield the Spliceosomal A complex (Wu and Manley 1989, Fleckner et al. 1997, Neubauer et al. 1998, Hartmuth et al. 2002, Rappsilber et al. 2002, Xu et al. 2004, Behzadnia et al. 2007, Shen et al. 2008, Chen et al. 2017, Zhang et al. 2020). The U4/U6.U5 tri-snRNP, containing the U4 snRNA base-paired with the U6 snRNA plus the U5 snRNP and accessory proteins, binds the Spliceosomal A complex to form the Spliceosomal Pre-B complex (Hausner et al. 1990, Kataoka and Dreyfuss 2004, Chi et al. 2013, Mohlmann et al. 2014, Boesler et al. 2016, Zhan et al. 2018, Charenton et al. 2019, Kastner et al. 2019, Townsend et al. 2020). The U1 snRNP is replaced at the 5' splice site by the U6 snRNA and the spliceosome is remodelled to yield the Spliceosomal B complex (Ismaïli et al. 2001, Deckert et al. 2006, Bessonov et al. 2008, Wolf et al. 2009, Bessonov et al. 2010, Schmidt et al. 2014, Boesler et al. 2016, Bertram et al. 2017, Zhang et al. 2018, Kastner et al. 2019). The Spliceosomal B complex is activated to form the Spliceosomal Bact complex by dissociation of the U4 snRNP and Lsm proteins from the U6 snRNA, freeing the U6 snRNA to form the active site of the spliceosome (Lamond et al. 1988, Laggerbauer et al. 1998, Ajuh et al. 2000, Bessonov et al. 2010, Agafonov et al. 2011, Haselbach et al. 2018, Zhang et al. 2018, Kastner et al. 2019, Busetto et al. 2020). Dissociation of the SF3A and SF3B subcomplexes of the U2 snRNP allows the intron branch point to dock near the 5' splice site, forming the B* Spliceosomal complex. Reaction of the branch point at the 5' splice site, yields the Spliceosomal C complex (Jurica et al. 2002, Makarov et al. 2002, Rappsilber et al. 2002, Reichert et al. 2002, Kataoka and Dreyfuss 2004, Bessonov et al. 2010, Gencheva et al. 2010, Agafonov et al. 2011, Alexandrov et al. 2012, Barbosa et al. 2012, Steckelberg et al. 2012, Schmidt et al. 2014, Zhan et al. 2018, Kastner et al. 2019, Busetto et al. 2020). The branch point is rotated to allow the 3' splice site to enter the active site, yielding the Spliceosomal C* complex (Ortlepp et al. 1998, Zhou and Reed 1998, Jurica et al. 2002, Makarov et al. 2002, Rappsilber et al. 2002, Ilagan et al. 2013, Bertram et al. 2017, Zhang et al. 2017, Kastner et al. 2019). Reaction of the 3' hydroxyl group of the upstream exon at the 3' splice site yields the Spliceosomal P (postcatalytic) complex (Zhou et al. 2000, Kataoka and Dreyfuss 2004, Tange et al. 2005, Zhang and Krainer 2007, Chi et al. 2013, Ilagan et al. 2013, Bertram et al. 2017, Zhang et al. 2017, Fica et al. 2019, Zhang et al. 2019). The Spliceosomal P complex then dissociates to yield an mRNP containing the spliced mRNA and associated proteins, including the exon junction complex (EJC) (Ohno and Shimura 1996, Merz et al. 2007, Yoshimoto et al. 2009, Zanini et al. 2017, Felisberto-Rodrigues et al. 2019, Zhang et al. 2019, EJC reviewed in Schlautmann and Gehring 2020), and the Intron Lariat Spliceosome (ILS), which contains the intron lariat. The ILS is then disassembled to free its components for further splicing reactions and the intron lariat is degraded (Wen et al. 2008, Yoshimoto et al. 2009, Yoshimoto et al. 2014, Zhang et al. 2019, Studer et al. 2020)."
BMGC_PW1566,BMG_PW4222,,,"The splicing of a subset of pre-mRNA introns occurs by a second pathway, designated the AT-AC or U12-dependent splicing pathway. AT-AC introns have highly conserved, non-canonical splice sites that are removed by the AT-AC spliceosome, which contains distinct snRNAs (U11, U12, U4atac, U6atac) that are structurally and functionally analogous to the major spliceosome. U5 snRNA as well as many of the protein factors appear to be conserved between the two spliceosomes."
BMGC_PW1567,BMG_PW4223,,,"The process in which excision of introns from the primary transcript of messenger RNA (mRNA) is followed by ligation of the two exon termini exposed by removal of each intron, is called mRNA splicing. Most of the mRNA is spliced by the major pathway, involving the U1, U2, U4, U5 and U6 snRNPs. A minor fraction, about 1 %, of the mRNAs are spliced via the U12 dependent pathway."
BMGC_PW1568,BMG_PW4224,,,"The 3' ends of eukaryotic mRNAs are generated by posttranscriptional processing of an extended primary transcript. For almost all RNAs, 3'-end processing consists of two steps: (i) the mRNA is first cleaved at a particular phosphodiester bond downstream of the coding sequence, (ii) the upstream fragment then receives a poly(A) tail of approximately 250 adenylate residues, whereas the downstream fragment is degraded. The two partial reactions are coupled so that reaction intermediates are usually undetectable. While 3' processing can be studied as an isolated event in vitro, it appears to be connected to transcription, splicing, and transcription termination in vivo. The only known exception to the rule of cleavage followed by polyadenylation are the major histone mRNAs, which are cleaved but not polyadenylated."
BMGC_PW1569,BMG_PW4225,,,"The best characterized case of C to U editing is in the intestinal apolipoprotein B transcript, where the editing event creates a premature translation stop codon and consequently leads to a shorter form of the protein. In the liver, C to U editing is important in the expression of specific isoforms of the apolipoprotein B enzyme. ApoB mRNA editing is a posttranscriptional, nuclear process that can be initiated after splicing, at the time of polyadenylation and is completed by the time pre-mRNA matures fully (reviewed by Blanc and Davidson, 2003). This editing event is a simple hydrolytic cytidine deamination to uridine, and is carried out by the Apobec-1 enzyme, along with the Apobec-1 complementing factor, ACF. The editing of apo-B mRNA involves the site-specific deamination of (C6666 to U), which converts codon 2153 from a glutamine codon, CAA, to a premature stop codon, UAA. As ACF is distributed in a variety of tissues, and these genes contain multiple family members, it is possible that editing events in additional targets will be found. The cis-acting regulatory elements for C to U editing include: 22 nt editing site within ApoB mRNA, 5' tripartite motif with an enhancer element adjacent to the target cytidine, a spacer element and mooring sequence both 3' to the cytidine (reviewed by Smith et al., 1997)."
BMGC_PW1570,BMG_PW4226,,,"Transport of mRNA through the Nuclear Pore Complex (NPC) is a dynamic process involving distinct machinery and receptor subsets. The separation of the two compartments and the regulation of this transport provide spatial and temporal control over mRNA expression and ultimately control over translation. It should be noted that mRNA export does not rely on a specific motif in the mRNA molecule, but rather transport appears to be coupled to processing and regulation. The specific proteins that are bound to the mRNA determine when it will be transported to the cytoplasm. This limitation insures that transport overwhelmingly favors transport of fully processed mRNA molecules."
BMGC_PW1571,BMG_PW4227,,,"Co-transcriptional pre-mRNA splicing is not obligatory. Pre-mRNA splicing begins co-transcriptionally and often continues post-transcriptionally. Human genes contain an average of nine introns per gene, which cannot serve as splicing substrates until both 5' and 3' ends of each intron are synthesized. Thus the time that it takes for pol II to synthesize each intron defines a minimal time and distance along the gene in which splicing factors can be recruited. The time that it takes for pol II to reach the end of the gene defines the maximal time in which splicing could occur co-transcriptionally. Thus, the kinetics of transcription can affect the kinetics of splicing.Any covalent change in a primary (nascent) mRNA transcript is mRNA Processing. For successful gene expression, the primary mRNA transcript needs to be converted to a mature mRNA prior to its translation into polypeptide. Eucaryotic mRNAs undergo a series of complex processing reactions; these begin on nascent transcripts as soon as a few ribonucleotides have been synthesized during transcription by RNA Polymerase II, through the export of the mature mRNA to the cytoplasm, and culminate with mRNA turnover in the cytoplasm."
BMGC_PW1572,BMG_PW4228,,,"Initiation of translation in the majority of eukaryotic cellular mRNAs depends on the 5'-cap (m7GpppN) and involves ribosomal scanning of the 5' untranslated region (5'-UTR) for an initiating AUG start codon. Therefore, this mechanism is often called cap-dependent translation initiation. Proximity to the cap, as well as the nucleotides surrounding an AUG codon, influence the efficiency of the start site recognition during the scanning process. However, if the recognition site is poor enough, scanning ribosomal subunits will ignore and skip potential starting AUGs, a phenomenon called leaky scanning. Leaky scanning allows a single mRNA to encode several proteins that differ in their amino-termini. Merrick (2010) provides an overview of this process and hghlights several features of it that remain incompletely understood. Several eukaryotic cell and viral mRNAs initiate translation by an alternative mechanism that involves internal initiation rather than ribosomal scanning. These mRNAs contain complex nucleotide sequences, called internal ribosomal entry sites, where ribosomes bind in a cap-independent manner and start translation at the closest downstream AUG codon. Initiation on several viral and cellular mRNAs is cap-independent and is mediated by binding of the ribosome to internal ribosome entry site (IRES) elements. These elements are often found in characteristically long structured regions on the 5'-UTR of an mRNA that may or may not have regulatory upstream open reading frames (uORFs). Both of these features on the 5'-end of the mRNA hinder ribosomal scanning, and thus promote a cap-independent translation initiation mechanism. IRESs act as specific translational enhancers that allow translation initiation to occur in response to specific stimuli and under the control of different trans-acting factors, as for example when cap-dependent protein synthesis is shut off during viral infection. Such regulatory elements have been identified in the mRNAs of growth factors, protooncogenes, angiogenesis factors, and apoptosis regulators, which are translated under a variety of stress conditions, including hypoxia, serum deprivation, irradiation and apoptosis. Thus, cap-independent translational control might have evolved to regulate cellular responses in acute but transient stress conditions that would otherwise lead to cell death, while the same mechanism is of major importance for viral mRNAs to bypass the shutting-off of host protein synthesis after infection. Encephalomyocarditis virus (EMCV) and hepatitis C virus exemplify two distinct mechanisms of IRES-mediated initiation. In contrast to cap-dependent initiation, the eIF4A and eIF4G subunits of eIF4F bind immediately upstream of the EMCV initiation codon and promote binding of a 43S complex. Accordingly, EMCV initiation does not involve scanning and does not require eIF1, eIF1A, and the eIF4E subunit of eIF4F. Nonetheless, initiation on some EMCV-like IRESs requires additional non-canonical initiation factors, which alter IRES conformation and promote binding of eIF4A/eIF4G. Initiation on the hepatitis C virus IRES is simpler: a 43S complex containing only eIF2 and eIF3 binds directly to the initiation codon as a result of specific interaction of the IRES and the 40S subunit."
BMGC_PW1573,BMG_PW4229,,,"The translation initiation complex forms when the 43S complex binds the mRNA that is associated with eIF4F, eIF4B and eIF4H. eIF4G in the eIF4F complex can directly contact eIF3 in the 43S complex. eIF1A is necessary for the formation of this complex."
BMGC_PW1574,BMG_PW4230,,,"The cap-binding complex is constituted by the initiation factors eIF4A, eIF4G and eIF4E. First, eIF4E must be released from the inactive eIF4E:4E-BP complex. Then eIF4A interacts with eIF4G, and eIF4E binds to the amino-terminal domain of eIF4G, resulting in the formation of the cap-binding complex eIF4F. eIF4A together with eIF4B or eIF4H is thought to unwind RNA secondary structures near the 5'-end of the mRNA. The translation initiation complex is formed when the 43S complex binds the cap-bound mRNA."
BMGC_PW1575,BMG_PW4231,,,The 80S ribosome dissociates into free 40S (small) and 60S (large) ribosomal subunits. Each ribosomal subunit is constituted by several individual ribosomal proteins and rRNA.
BMGC_PW1576,BMG_PW4232,,,"Binding of the methionyl-tRNA initiator to the active eIF2:GTP complex results in the formation of the ternary complex. Subsequently, this Met-tRNAi:eIF2:GTP (ternary) complex binds to the complex formed by the 40S subunit, eIF3 and eIF1A, to form the 43S complex."
BMGC_PW1577,BMG_PW4233,,,"The 80S ribosome bound to the mRNA moves along the mRNA molecule from its initial site to the initiation codon and forms a 48S complex, in which the initiation codon is base paired to the anticodon of the Met-tRNAi. Proper recognition of the AUG initiation codon depends on base pairing with the anticodon of the Met-tRNAi and requires eIF1, eIF1A, eIF2 and eIF5."
BMGC_PW1578,BMG_PW4234,,,"Hydrolysis of eIF2-GTP occurs after the Met-tRNAi has recognized the AUG. This reaction is catalyzed by eIF5 (or eIF5B) and is thought to cause dissociation of all other initiation factors and allow joining of the large 60S ribosomal subunit. The 60S subunit joins - a reaction catalyzed by eIF5 or eIF5B - resulting in a translation-competent 80S ribosome. Following 60S subunit joining, eIF5B hydrolyzes its GTP and is released from the 80S ribosome, which is now ready to start elongating the polypeptide chain."
BMGC_PW1579,BMG_PW4235,,,"The active eIF2:GTP complex may be formed by direct binding of GTP to free eIF2 or by GDP-GTP exchange on the eIF2:GDP:eIF2B complex. The eIF2:GDP complex binds eIF2B forming an eIF2:GDP:eIF2B intermediate complex. eIF2B is a guanine nucleotide releasing factor required to cause GDP release so that a new GTP molecule can bind and activate eIF2. Phosphorylated eIF2:GDP sequesters all eIF2B as an inactive complex, and thus, reuse of eIF2 is inhibited as a consequence of the tight bond it forms with eIF2B, which prevents nucleotide exchange. Therefore, in the absence of free eIF2B, excess eIF2 remains in its inactive GDP-bound form and protein synthesis slows dramatically."
BMGC_PW1580,BMG_PW4236,,,"Translation initiation is a complex process in which the Met-tRNAi initiator, 40S, and 60S ribosomal subunits are assembled by eukaryotic initiation factors (eIFs) into an 80S ribosome at the start codon of an mRNA. The basic mechanism for this process can be described as a series of five steps: 1) formation of a pool of free 40S subunits, 2) formation of the ternary complex (Met-tRNAi/eIF2/GTP), and subsequently, the 43S complex (comprising the 40S subunit, Met-tRNAi/eIF2/GTP, eIF3 and eIF1A), 3) activation of the mRNA upon binding of the cap-binding complex eIF4F, and factors eIF4A, eIF4B and eIF4H, with subsequent binding to the 43S complex, 4) ribosomal scanning and start codon recognition, and 5) GTP hydrolysis and joining of the 60S ribosomal subunit."
BMGC_PW1581,BMG_PW4237,,,"The arrival of any of the three stop codons (UAA, UAG and UGA) into the ribosomal A-site triggers the binding of a release factor (RF) to the ribosome and subsequent polypeptide chain release. In eukaryotes, the RF is composed of two proteins, eRF1 and eRF3. eRF1 is responsible for the hydrolysis of the peptidyl-tRNA, while eRF3 provides a GTP-dependent function. The ribosome releases the mRNA and dissociates into its two complex subunits, which can reassemble on another molecule to begin a new round of protein synthesis. It should be noted that at present, there is no factor identified in eukaryotes that would be the functional equivalent of the bacterial ribosome release (or recycling) factor, RRF, that catalyzes dissociation of the ribosome from the mRNA following release of the polypeptide"
BMGC_PW1582,BMG_PW4238,,,"Nucleotide sugars are used as sugar donors by glycosyltransferases to create the sugar chains for glycoconjugates such as glycoproteins, polysaccharides and glycolipids. Glycosyltransferases reside mainly in the lumen of the Golgi apparatus and endoplasmic reticulum (ER) whereas nucleotide sugars are synthesized in the cytosol. The human solute carrier family SLC35 encode nucleotide sugar transporters (NSTs) which can mediate the antiport of nucleotide sugars in exchange for the corresponding nucleoside monophosphates (eg. UMP for UDP-sugars). Owing to their function, NSTs are primarily located on Golgi and ER membranes (He L et al, 2009; Handford M et al, 2006; Ishida N and Kawakita M, 2004)."
BMGC_PW1583,BMG_PW4239,,,"The activity of the upstream binding factor (UBF-1) plays an important role in the regulation of rRNA synthesis. Studies reveal that phosphorylation of UBF-1 is required for its interaction with the RNA polymerase I complex, suggesting that phosphorylation of UBF-1 bound to the rDNA promoter during promoter opening modulates the assembly of the transcription initiation complex."
BMGC_PW1584,BMG_PW4240,,,"As the active RNA Polymerase I complex leaves the promoter Rrn3 dissociates from the complex. RNA polymerase I Promoter Clearance is complete and Chain Elongation begins (Milkereit and Tschochner, 1998). The assembly of the initiation complex on the promoter and the transition from a closed to an open complex is then followed by promoter clearance and transcription elongation by RNA Pol I. Unlike the RNA polymerase II system, RNA polymerase I transcription does not require a form of energy such as ATP for initiation and elongation. Regulatory mechanisms operating at both the level of transcription initiation and elongation probably concurrently to adjust the level of rRNA synthesis to the need of the cell."
BMGC_PW1585,BMG_PW4241,,,RNA Polymerase II promoter escape occurs after the first phosphodiester bond has been created.
BMGC_PW1586,BMG_PW4242,,,"Formation of the pre-initiation complex proceeds in five steps, recognition and binding of core promoter elements by TFIID, binding of TFIIA and TFIIB to the pol II promoter:TFIID complex, recruitment of RNA Polymerase II Holoenzyme by TFIIF to the pol II promoter:TFIID:TFIIA:TFIIB complex, binding of TFIIE to the growing preinitiation complex, and formation of the closed pre-initiation complex (Orphanides et al. 1997)."
BMGC_PW1587,BMG_PW4243,,,Pol III initiation complexes open the promoter spontaneously similar to the mechanism employed in archaeal and bacterial transcription.
BMGC_PW1588,BMG_PW4244,,,"The purine ribonucleotide inosine 5'-monophosphate (IMP) is assembled on 5-phospho-alpha-D-ribose 1-diphosphate (PRPP), with atoms derived from aspartate, glutamine, glycine, N10-formyl-tetrahydrofolate, and carbon dioxide. Although several of the individual reactions in this sequence are reversible, as indicated by the double-headed arrows in the diagram, other irreversible steps drive the pathway in the direction of IMP synthesis in the normal cell. All of these reactions are thus annotated here only in the direction of IMP synthesis. Guanosine 5'-monophosphate (GMP) and adenosine 5'-monophosphate (AMP) are synthesized from IMP."
BMGC_PW1589,BMG_PW4246,,,"Promoter clearance is one of the rate-limiting steps in Polymerase I transcription. This step is composed of three phases, promoter opening, transcription initiation and promoter escape."
BMGC_PW1590,BMG_PW4247,,,"Maintenance of chromosomal organization is critical for stable chromosome function. Two aspects of maintenance annotated in Reactome are centromeric chromatin assembly outside the context of DNA replication, involving nucleosome assembly with the histone H3 variant CenH3 (also called CENP-A), and the maintenance of telomeres, protein-DNA complexes at the ends of linear chromosomes that are important for genome stability."
BMGC_PW1591,BMG_PW4248,,,"The death receptors (DR), all cell-surface receptors, that belong to the TNF receptor superfamily (TNFRSF). The term death receptor refers to those members of the TNFRSF that contain a ""death domain"" (DD) within their cytoplasmic tail which provides the capacity for protein–protein interactions with other DD-containing proteins suach as FADD. The main signals transmitted from TNF death receptors such as TNFR1, TRAIL-R, and CD95/FAS in response to their cognate ligand binding result in an apoptotic signaling pathway characterized by direct activation of intracellular cysteine proteases (caspases), without directly involving the mitochondrial death pathway. However, these death receptors have also been shown to initiate survival signals via the activation of transcription factors NFκappaB and AP1. This project describes an assembly of the death-inducing signaling complex (DISC) downstream of TNFR1, TRAIL-R, and CD95/FAS and shows protein composition and stoichiometry within the DISC. However, the DISC signaling complex may vary in its components stoichiometry. DR signaling may trigger formation of higher order receptor structures or signaling through rearrangement of receptor chains, which is not reflected here. The project also describes neuron-type-specific signaling by the p75NTR death receptor (also known as NGFR) that can regulate a number of different biological activities in response to ligand binding, including cell death and/or survival, axonal growth and synaptic plasticity."
BMGC_PW1592,BMG_PW4249,,,"In addition to various processes for removing lesions from the DNA, cells have developed specific mechanisms for tolerating unrepaired damage during the replication of the genome. These mechanisms are collectively called DNA damage bypass pathways. The Y family of DNA polymerases plays a key role in DNA damage bypass. Y family DNA polymerases, REV1, POLH (DNA polymerase eta), POLK (DNA polymerase kappa) and POLI (DNA polymerase iota), as well as the DNA polymerase zeta (POLZ) complex composed of REV3L and MAD2L2, are able to carry out translesion DNA synthesis (TLS) or replicative bypass of damaged bases opposite to template lesions that arrest high fidelity, highly processive replicative DNA polymerase complexes delta (POLD) and epsilon (POLE). REV1, POLH, POLK, POLI and POLZ lack 3'->5' exonuclease activity and exhibit low fidelity and weak processivity. The best established TLS mechanisms are annotated here. TLS details that require substantial experimental clarification have been omitted. For recent and past reviews of this topic, please refer to Lehmann 2000, Friedberg et al. 2001, Zhu and Zhang 2003, Takata and Wood 2009, Ulrich 2011, Saugar et al. 2014."
BMGC_PW1593,BMG_PW4250,,,"Depurination of a damaged nucleotide is mediated by a purine-specific DNA glycosylase. The glycosylase cleaves the N-C1' glycosidic bond between the damaged DNA base and the deoxyribose sugar, generating a free base and an abasic i.e. apurinic/apyrimidinic (AP) site (Slupphaug et al. 1996, Parikh et al. 1998)."
BMGC_PW1594,BMG_PW4251,,,Depyrimidination of a damaged nucleotide in DNA is mediated by a pyrimidine-specific DNA glycosylase. The glycosylase cleaves the N-C1' glycosidic bond between the damaged DNA base and the deoxyribose sugar generating a free base and an abasic i.e. apurinic/apyrimidinic (AP) site (Lindahl and Wood 1999).
BMGC_PW1595,BMG_PW4252,,,"Base excision repair is initiated by DNA glycosylases that hydrolytically cleave the base-deoxyribose glycosyl bond of a damaged nucleotide residue, releasing the damaged base (Lindahl and Wood 1999, Sokhansanj et al. 2002)."
BMGC_PW1596,BMG_PW4253,,,"Abasic sugar phosphate removal via the single nucleotide replacement pathway requires displacement of DNA glycosylase by APEX1, APEX1-mediated endonucleolytic cleavage at the 5' side of the base free deoxyribose residue, recruitment of POLB to the AP site and excision of the abasic sugar phosphate (5'dRP) residue at the strand break (Lindahl and Wood, 1999)."
BMGC_PW1597,BMG_PW4254,,,"Resolution of AP sites can occur through the single nucleotide replacement pathway or through the multiple nucleotide patch replacement pathway, also known as the long-patch base excision repair (BER). Except for the APEX1-independent resolution of AP sites via single nucleotide base excision repair mediated by NEIL1 or NEIL2 (Wiederhold et al. 2004, Das et al. 2006), single nucleotide and multiple-nucleotide patch replacement pathways are both initiated by APEX1-mediated displacement of DNA glycosylases and cleavage of the damaged DNA strand by APEX1 immediately 5' to the AP site (Wilson et al. 1995, Bennett et al. 1997, Masuda et al. 1998). The BER proceeds via the single nucleotide replacement when the AP (apurinic/apyrimidinic) deoxyribose residue at the 5' end of the APEX1-created single strand break (SSB) (5'dRP) can be removed by the 5'-exonuclease activity of DNA polymerase beta (POLB) (Bennett et al. 1997). POLB fills the created single nucleotide gap by adding a nucleotide complementary to the undamaged DNA strand to the 3' end of the SSB. The SSB is subsequently ligated by DNA ligase III (LIG3) which, in complex with XRCC1, is recruited to the BER site by an XRCC1-mediated interaction with POLB (Kubota et al. 1996). BER proceeds via the multiple-nucleotide patch replacement pathway when the AP residue at the 5' end of the APEX1-created SSB undergoes oxidation-related damage (5'ddRP) and cannot be cleaved by POLB (Klungland and Lindahl 1997). Long-patch BER can be completed by POLB-mediated DNA strand displacement synthesis in the presence of PARP1 or PARP2, FEN1 and DNA ligase I (LIG1) (Prasad et al. 2001). When the PCNA-containing replication complex is available, as is the case with cells in S-phase of the cell cycle, DNA strand displacement synthesis is catalyzed by DNA polymerase delta (POLD) or DNA polymerase epsilon (POLE) complexes, in the presence of PCNA, RPA, RFC, APEX1, FEN1 and LIG1 (Klungland and Lindahl 1997, Dianova et al. 2001). It is likely that the 9-1-1 repair complex composed of HUS1, RAD1 and RAD9 interacts with and coordinates components of BER, but the exact mechanism and timing have not been elucidated (Wang et al. 2004, Smirnova et al. 2005, Guan et al. 2007, Balakrishnan et al. 2009)."
BMGC_PW1598,BMG_PW4255,,,"DNA damage can be directly reversed by dealkylation (Mitra and Kaina 1993). Three enzymes play a major role in reparative DNA dealkylation: MGMT, ALKBH2 and ALKBH3. MGMT dealkylates O-6-methylguanine in a suicidal reaction that inactivates the enzyme (Daniels et al. 2000, Rasimas et al. 2004, Duguid et al. 2005, Tubbs et al. 2007), while ALKBH2 and ALKBH3 dealkylate 1-methyladenine, 3-methyladenine, 3-methylcytosine and 1-ethyladenine (Duncan et al. 2002, Dango et al. 2011)."
BMGC_PW1599,BMG_PW4256,,,"DNA in cells is susceptible to different types of cytotoxic and mutagenic damage caused by alkylating agents. These genotoxic chemicals generate major lesions like 1-methyladenine, 3-methyladenine, 3-methylcytosine and O6-methylguanine in DNA. Cells have built in repair mechanisms against such toxic molecules. For example, 3-methyladeninie-DNA glycosylases excise some methylated bases while MGMT/hAGT protein transfers alkyl groups from others lesions onto cysteine residues. E.coli AlkB protein has a unique function wherein 1-methyladenine and 3-methylcytosine are demethylated by a combination of oxidative decarboxylation and hydroxylation activities. AlkB and its human orthologs, ALKBH2 (ABH2) and ALKBH3 (ABH3) belong to alpha-ketoglutarate deoxygenase family of enzymes that oxidize chemically inert compounds in the presence of alpha-ketoglutarate, oxygen and ferrous ions. As a byproduct of these chemical reactions, formaldehyde is released in the case of methylated lesions and acetaldehyde in the case 1-ethyladenine in DNA. CO2 and succinate are also released in an intermediate step not shown in the following illustration. Unlike other mechanisms which involve some kind of nuclease activities, this type of repair mechanism leaves the repaired bases intact by just removing the reactive alkyl groups that get bound to the bases thereby effecting accurate restoration of damaged DNA sequences (Trewick et al. 2002, Duncan et al. 2002, Sedgwick 2004)."
BMGC_PW1600,BMG_PW4257,,,"At the end of the cycle, the elongation complex (EC) must be destabilized to release its transcript and DNA. Analogous to initiation, cis-signals and protein factors are required to mediate EC destabilization and release of the transcript from the grip of the RNA polymerase (RNAP). RNAP III achieves efficient termination despite the apparent simplicity of its cis-acting DNA terminator element, a stretch of five or more T residues on the non-template (NT) strand, which directs termination within this site without need for additional cis-elements or trans-acting factors."
BMGC_PW1601,BMG_PW4258,,,"Gene expression encompasses transcription and translation and the regulation of these processes. RNA Polymerase I Transcription produces the large preribosomal RNA transcript (45S pre-rRNA) that is processed to yield 18S rRNA, 28S rRNA, and 5.8S rRNA, accounting for about half the RNA in a cell. RNA Polymerase II transcription produces messenger RNAs (mRNA) as well as a subset of non-coding RNAs including many small nucleolar RNAs (snRNA) and microRNAs (miRNA). RNA Polymerase III Transcription produces transfer RNAs (tRNA), 5S RNA, 7SL RNA, and U6 snRNA. Transcription from mitochondrial promoters is performed by the mitochondrial RNA polymerase, POLRMT, to yield long transcripts from each DNA strand that are processed to yield 12S rRNA, 16S rRNA, tRNAs, and a few RNAs encoding components of the electron transport chain. Regulation of gene expression can be divided into epigenetic regulation, transcriptional regulation, and post-transcription regulation (comprising translational efficiency and RNA stability). Epigenetic regulation of gene expression is the result of heritable chemical modifications to DNA and DNA-binding proteins such as histones. Epigenetic changes result in altered chromatin complexes that influence transcription. Gene Silencing by RNA mostly occurs post-transcriptionally but can also affect transcription. Small RNAs originating from the genome (miRNAs) or from exogenous RNA (siRNAs) are processed and transferred to the RNA-induced silencing complex (RISC), which interacts with complementary RNA to cause cleavage, translational inhibition, or transcriptional inhibition."
BMGC_PW1602,BMG_PW4259,,,"IRS is one of the mediators of insulin signalling events. It is activated by phosphorylation and triggers a cascade of events involving PI3K, SOS, RAF and the MAP kinases. The proteins mentioned under IRS are examples of IRS family members acting as indicated. More family members are to be confirmed and added in the future. Using receptor mutagenesis studies it is known that IRS1 via its PTB domain binds to the insulin receptor at the juxtamembrane region at tyrosine 972. The interaction is further stabilized by the PH domain of IRS1 which interacts with the phospholipids of the plasma membrane. This allows the receptor to phosphorylate IRS1 on up to 13 of its tyrosine residues. Once phosphorylated the IRS1 falls away from the receptor. Now in a tyrosine phosphorylated and hence activated state other proteins can interact with the IRS proteins."
BMGC_PW1603,BMG_PW4260,,,"Now with the complete receptor-ligand dissociation and subsequent degradation of insulin in the endosomal lumen, the endosomally associated protein tyrosine phosphatases (PTPs) complete the receptor dephosphorylation. So too are all the receptor substrates dephosphorylated leading to the collapse of the signalling complexes and signal attenuation."
BMGC_PW1604,BMG_PW4261,,,"Autophosphorylation of the insulin receptor triggers a series of signalling events, mediated by SHC or IRS, and resulting in activation of the Ras/RAF and MAP kinase cascades. A second effect of the autophosphorylation of the insulin receptor is its internalisation into an endosome, which downregulates its signalling activity."
BMGC_PW1605,BMG_PW4262,,,"Abortive initiation, the repetitive formation of short oligonucleotides, is a ubiquitous feature of transcriptional initiation. This Pathway contains events inferred from events in Saccharomyces cerevisiae."
BMGC_PW1606,BMG_PW4263,,,DNA damage induced activation of the checkpoint kinases Chk1/Chk2(Cds1) results in the conversion and/or maintenance of CyclinB:Cdc2 complex in its Tyrosine 15 phosphorylated (inactive) state. Cdc2 activity is regulated by a balance between the phosphorylation and dephosphorylation by the Wee1/Myt1 kinase and Cdc25 phosphatase. Inactivation of the Cyclin B:Cdc2 complex likely involves both inactivation of Cdc25 and/or stimulation of Wee1/Myt1 kinase activity.
BMGC_PW1607,BMG_PW4265,,,"Co-transcriptional pre-mRNA splicing is not obligatory. Pre-mRNA splicing begins co-transcriptionally and often continues post-transcriptionally. Human genes contain an average of nine introns per gene, which cannot serve as splicing substrates until both 5' and 3' ends of each intron are synthesized. Thus the time that it takes for pol II to synthesize each intron defines a minimal time and distance along the gene in which splicing factors can be recruited. The time that it takes for pol II to reach the end of the gene defines the maximal time in which splicing could occur co-transcriptionally. Thus, the kinetics of transcription can affect the kinetics of splicing. There are two classes of intronless pre-mRNAs (mRNAs expressed from genes that lack introns). The first class encodes the replication dependent histone mRNAs. These mRNAs have unique 3' ends that do not have a polyA tail. The replication dependent histone mRNAs in all metazoans, as well as Chlamydomonas and Volvox fall into this class. The second class of mRNAs end in polyA tails, which are formed by a mechanism similar to that which poly-adenylate pre-mRNAs containing introns. In the intronless genes there is a different method of replacing the 3' splice site that activates polyadenylation."
BMGC_PW1608,BMG_PW4266,,,"After transcription, some RNA molecules are altered to contain bases not encoded in the genome. Most often this involves the editing or modification of one base to another, but in some organisms can involve the insertion or deletion of a base. Such editing events alter the coding properties of mRNA. RNA editing can be generally defined as the co- or post transcriptional modification of the primary sequence of RNA from that encoded in the genome through nucleotide deletion, insertion, or base modification mechanisms. There are two pathways of RNA editing: the substitution/conversion pathway and the insertion/deletion pathway. The insertion/deletion editing occurs in protozoans like Trypanosoma, Leishmania; in slime molds like Physarum spp., and in some viral categories like paramyxoviruses, Ebola virus etc. To date, the substitution/conversion pathway has been observed in human along with other mammals, Drosophila, and some plants. The RNA editing processes are known to create diversity in proteins involved in various pathways like lipid transport, metabolism etc. and may act as potential targets for therapeutic intervention (Smith et al., 1997). The reaction mechanisms of cytidine and adenosine deaminases is represented below. In both these reactions, NH3 is presumed to be released:"
BMGC_PW1609,BMG_PW4267,,,"The editosome for C to U editing in mammals consist of a member of cytidine deaminase family of enzymes, apoB mRNA editig catalytic polypeptide 1 (APOBEC-1) and a complementing specificity factor (ACF) in addition to the target mRNA."
BMGC_PW1610,BMG_PW4269,,,Fatty acyl-CoA biosynthesis involves following steps: -Palmitate synthesis catalyzed by Acetyl-CoA carboxylase and Fatty acid synthase -Conversion of palmitic acid to long chain fatty acids and -Conversion of long chain fatty acids to fatty acyl-CoA by acyl-CoA synthases.
BMGC_PW1611,BMG_PW4270,,,"BID may promote cell death by activating BAX and BAK while inactivating anti-apoptotic proteins. The engagement of cell surface receptors activates the caspase-8, a heterodimer, that cleaves BID in its amino terminal region. This particular event may act as a link between Extrinsic (caspase 8/10 dependent) and Intrinsic (Bcl-2 inhibitable) pathways although some evidences from mouse genetic experiments suggest the contrary. It has been suggested that the death signals from the extrinsic or death receptor pathway may get amplified by the mechanisms of intrinsic pathway and that this functional loop may be enabled by the molecules like tBID (truncated BID). Cleavage of BID to tBID can also be achieved by Granzyme B. The truncated protein is myristoylated and translocates to mitochondria."
BMGC_PW1612,BMG_PW4271,,,"In the execution phase of apoptosis, effector caspases cleave vital cellular proteins leading to the morphological changes that characterize apoptosis. These changes include destruction of the nucleus and other organelles, DNA fragmentation, chromatin condensation, cell shrinkage and cell detachment and membrane blebbing (reviewed in Fischer et al., 2003)."
BMGC_PW1613,BMG_PW4272,,,"Cyclin D turnover is regulated by ubiquitination and proteasomal degradation which are positively regulated by cyclin D phosphorylation on threonine-286 (Diehl et al., 1997). After the Cyclin D serves the role of mediating reactions by Cdk4 and Cdk6, it is shuttled to the cytoplasm and degraded in a ubiquitin-dependent manner. Whether Cdk4 and Cdk6 are truly redundant is a topic still under investigation, although both the kinases are required for normal cell cycle progression. Destruction of the D type cyclins accompanies the end of the G1 phase, and the E type cyclins are involved in transition of the cell from G1 to S phase."
BMGC_PW1614,BMG_PW4273,,,"Very long-chain fatty acids (VLCFA), ones with more than 20 carbon atoms, have diverse physiological roles, notably as components of ceramides in membrane lipids and as precursors of the eicosanoid hormones that play central roles in the generation and resolution of inflammatory responses. Saturated and monounsaturated VLCFAs can be synthesized by elongation of palmitic acid synthesized de novo or derived from the diet. Polyunsaturated VLCFAs are synthesized from dietary linoleic and linolenic acids - humans lack the desaturase enzymes to synthesize these molecules from stearate. Chemically, the elongation process that yields VLCFA parallels the one by which palmitate (16 carbons) or stearate (18 carbons) are synthesized de novo from acetate. The starting fatty acid is activated by conjugation with coenzyme A (CoA-SH), condensed with malonyl-CoA to form a 3-oxoacyl CoA containing two more carbon atoms than the starting long chain fatty acyl CoA and CO2, reduced with NADPH to a 3-hydroxyacyl CoA, dehydrated to a trans 2,3-enoyl-CoA, and reduced with NADPH to yield a fatty acyl-CoA two carbons longer than the starting one. The process differs from the de novo one in that the enzymatic activities resposible for each step are expressed by different proteins associated with the endoplasmic reticulum membrane, not by separate domains of a single multifunctional cytosolic protein. In humans, activation is catalyzed by one of five acyl-CoA synthetase long-chain (ACSL) enzymes, conjugation by one of seven elongation of very long chain fatty acids (ELOVL) proteins, reduction by one of two HSB17B estradiol dehydrogenases, dehydration by one of four protein tyrosine phosphatase-like / 3-hydroxyacyl-CoA dehydratase (PTPL / HACD) proteins, and reduction by one of two trans-2,3-enoyl-CoA reductase (TECR) proteins. Members of the four enzyme families differ in their tissue-specific expression patterns and in their substrate preferences (chain length, degree of saturation), leading to tissue-specific complements of VLCA (Jakobsson et al. 2006; Kihara 2012; Nugteren 1965; Sassa & Kihara 2014). Here the full two-carbon elongation cycle to form stearate from palmitate is annotated, as well as the activation and condensation steps for elongation of arachidonate, the 20-carbon unsaturated fatty acid that plays a central role in the synthesis of prostaglandins and related hormones."
BMGC_PW1615,BMG_PW4274,,,"Initiation of platelet adhesion is the first step in the formation of the platelet plug. Circulating platelets are arrested and subsequently activated by exposed collagen and von Willebrand factor (VWF). It is not entirely clear which type of collagen is responsible for adhesion and activation; collagen types I and III are abundant in vascular epithelia but several other types including IV are present (Farndale RW 2006). Several collagen binding proteins are expressed on platelets, including integrin alpha2 beta1 (α2β1 or ITGA2:ITGB1), GPVI, and GPIV. ITGA2:ITGB1, known on leukocytes as VLA-2, is the major platelet collagen receptor (Kunicki TJ et al., 1988). ITGA2:ITGB1 (α2β1) requires Mg2+ to interact with collagen. The activation of ITGA2:ITGB1 (α2β1) is modulated by the activation of integrin alphaIIb beta3 (αIIbβ3 or ITGA2B:ITGB3), which functions as a platelet receptor for fibrinogen and VWF (van de Walle GR et al., 2007). The I domain of α2 (ITGA2) subunit binds a collagen motif with the sequence Gly-Phe-Hyp-Gly-Glu-Arg (Emsley J et al., 2000). Binding of collagen to ITGA2:ITGB1 (α2β1) generates intracellular signals that contribute to platelet activation. These interactions facilitate the engagement of the lower-affinity collagen receptor, GPVI (Tsuji M et al., 1997), the key receptor involved in collagen-induced platelet activation. The GPVI receptor is a complex of the GPVI protein with a dimer of Fc epsilon R1 gamma (FceRI gamma). The Src family kinases Fyn and Lyn constitutively associate with the GPVI:FceRIgamma complex in platelets and initiate platelet activation through phosphorylation of the immunoreceptor tyrosine-based activation motif (ITAM) in FceRI gamma, leading to binding and activation of the tyrosine kinase Syk. Downstream of Syk, a series of adapter molecules and effectors lead to platelet activation. VWF circulates in plasma as a multimeric molecule that senses hydrodynamic shear forces in the bloodstream (Reininger AJ 2008; Mojzisch A & Brehm MA 2021). Upon vascular injury, circulating VWF binds to subendothelial collagen, which becomes exposed to the flowing blood (Bergmeier W & Hynes RO 2012; Colace TV & Diamond SL 2013). Upon binding to collagen, VWF becomes anchored to the damaged surface. Shear forces then induce conformational changes to mechanosensitive VWF causing the bound VWF to stretch and unfold (Li F et al., 2004; Schneider SW et al., 2007; Fu H et al., 2017). VWF unfolding leads to exposure of the A1 domain to allow binding to glycoprotein Ib α (GPIbα, encoded by GP1BA), a subunit of the platelet surface GPIb:IX:V complex (Dumas JJ et al., 2004; Ju L et al., 2013). Shear-induced aggregation is achieved when VWF interacts both with exposed collagen and platelets to initiate platelet adhesion to vascular injury sites. The interaction between VWF and GPIb is regulated by shear force; an increase in the shear stress results in a corresponding increase in the affinity of VWF for GPIb."
BMGC_PW1616,BMG_PW4275,,,"Platelet activation begins with the initial binding of adhesive ligands and of the excitatory platelet agonists (released or generated at the sites of vascular trauma) to cognate receptors on the platelet membrane (Ruggeri 2002). Intracellular signaling reactions then enhance the adhesive and procoagulant properties of tethered platelets or of platelets circulating in the proximity. Once platelets have adhered they degranulate, releasing stored secondary agents such as ADP, ATP, and synthesize thromboxane A2. These amplify the response, activating and recruiting further platelets to the area and promoting platelet aggregation. These amplify the response, activating and recruiting further platelets to the area and promoting platelet aggregation. Adenosine nucleotides signal through P2 purinergic receptors on the platelet membrane. ADP activates P2Y1 and P2Y12, which signal via both the alpha and gamma:beta components of the heterotrimeric G-protein (Hirsch et al. 2001, 2006), while ATP activates the ionotropic P2X1 receptor (Kunapuli et al. 2003). Activation of these receptors initiates a complex signaling cascade that ultimately results in platelet activation, aggregation and thrombus formation (Kahner et al. 2006). Integrin AlphaIIbBeta3 is the most abundant platelet receptor, with 40 000 to 80 000 copies per resting platelet, acting as a major receptor for fibrinogen and other adhesive molecules (Wagner et al. 1996). Activation of AlphaIIbBeta3 enhances adhesion and leads to platelet-platelet interactions, and thus aggregation (Philips et al. 1991). GP VI is the most potent collagen receptor initiating signal generation, an ability derived from its interaction with the FcRI gamma chain. This results in the phosphorylation of the gamma-chain by non-receptor tyrosine kinases of the Src family (1). The phosphotyrosine motif is recognized by the SH2 domains of Syk, a tyrosine kinase. This association activates the Syk enzyme, leading to activation (by tyrosine phosphorylation) of PLC gamma2 (2). Thrombin is an important platelet agonist generated on the membrane of stimulated platelets. Thrombin acts via cell surface Protease Activated Receptors (PARs). PARs are G-protein coupled receptors activated by a proteolytic cleavage in an extracellular loop (Vu, 1991) (3). Activated PARs signal via G alpha q (4) and via the beta:gamma component of the G-protein (5). Both stimulate PLC giving rise to PIP2 hydrolysis and consequent activation of PI3K (6). PLCgamma2 activation also gives rise to IP3 (7) which stimulates the IP3 receptor (8) leading to increased intracellular calcium. Platelet activation further results in the scramblase-mediated transport of negatively-charged phospholipids to the platelet surface. These phospholipids provide a catalytic surface (with the charge provided by phosphatidylserine and phosphatidylethanolamine) for the tenase complex (formed by the activated forms of the blood coagulation factors factor VIII and factor I)."
BMGC_PW1617,BMG_PW4276,,,"Activation of phospholipase C enzymes results in the generation of second messengers of the phosphatidylinositol pathway. The events resulting from this pathway are a rise in intracellular calcium and activation of Protein Kinase C (PKC). Phospholipase C cleaves the phosphodiester bond in PIP2 to form 1,2 Diacylglycerol (DAG) and 1,4,5-inositol trisphosphate (IP3). IP3 opens Ca2+ channels in the platelet dense tubular system, raising intracellular Ca2+ levels. DAG is a second messenger that regulates a family of Ser/Thr kinases consisting of PKC isozymes (Nishizuka 1995). DAG achieves activation of PKC isozymes by increasing their affinity for phospholipid. Most PKC enzymes are also calcium-dependent, so their activation is in synergy with the rise in intracellular Ca2+. Platelets contain several PKC isoforms that can be activated by DAG and/or Ca2+ (Chang 1997)."
BMGC_PW1618,BMG_PW4277,,,"The transcription cycle is divided in three major phases: initiation, elongation, and termination. Transcription initiation include promoter DNA binding, DNA melting, and initial synthesis of short RNA transcripts. Many changes must occur to the RNA polymerase II (pol II) transcription complex as it makes the transition from initiation into transcript elongation. During this intermediate phase of transcription, contact with initiation factors is lost and stable association with the nascent transcript is established. These changes collectively comprise promoter clearance."
BMGC_PW1619,BMG_PW4278,,,"There are three basic types of RNA polymerase III promoters. The three types of RNA polymerase III promoters are known as type 1, type 2, and type 3 promoters. Type 1 promoters are found in the 5S genes and consist of a gene-internal element called the internal control region (ICR), that is subdivided into A block, intermediate element, and C block (Bogenhagen, 1985; Sakonju et al., 1980). Type 2 promoters are found in tRNA genes, Adenovirus 2 VAI gene, and other genes (Galli et al., 1981; Sharp et al., 1981). These promoters consists of two gene-internal elements called the A and the B boxes. Type 3 promoters consist of a distal sequence element (DSE) that serves as an enhancer, a proximal sequence element (PSE), and a TATA box (Baer et al., 1989; Lobo and Hernandez, 1989). Some promoters combine elements from type 2 and 3 promoters. For example, the S. cerevisiae U6 promoter, also shown in the figure, contains the TATA box typical of type 3 promoters and the A and B boxes typical of type 2 promoters. Moreover, in S. pombe, nearly all tRNA and 5S genes contain a TATA box in addition to gene-internal elements, and the TATA box is required for transcription."
BMGC_PW1620,BMG_PW4279,,,"The type 1 promoters recruit TFIIIA, the founding member of the C2H2 zinc finger family of DNA-binding proteins (Engelke et al., 1980; Sakonju et al., 1981). The binding of TFIIIA then allows the binding of TFIIC (Lassar et al., 1983), a complex consisting of five subunits (which differs from the six subunits in S. cerevisiae) in human cells and S. pombe. Once the DNA/TFIIIA/TFIIIC complex is formed, Brf1-TFIIIB joins the complex and this in turn allows the recruitment of RNA polymerase III (Bieker et al., 1985; Setzer and Brown, 1985)."
BMGC_PW1621,BMG_PW4280,,,"The type 2 promoters can recruit TFIIIC without the help of TFIIIA because TFIIIC binds directly to the A and B boxes. As for the type 1 promoters, this then allows the binding of Brf1-TFIIIB and RNA polymerase III. Importantly, in the yeast system, once Brf1-TFIIIB has been recruited to type 1 or 2 promoters, TFIIIA and/or TFIIIC can be stripped from the DNA with high salt or heparin treatment. Brf1-TFIIIB remains bound to the DNA and is sufficient to direct multiple rounds of transcription ."
BMGC_PW1622,BMG_PW4281,,,"The metazoan-specific type 3 promoters, which are exemplified by the human U6 promoter, recruit a complex variously called the snRNA activating protein complex (SNAPc) (Sadowski et al., 1993), the PSE binding protein (PBP) (Waldschmidt et al., 1991), or the PSE transcription factor (PTF) (Murphy et al., 1992). The complex contains five types of subunits and binds to the PSE. Type 3 promoters also recruit Brf2-TFIIIB through a combination of protein-protein contacts with SNAPc and a direct association of the TBP component of Brf2-TFIIIB with the TATA box. This then allows RNA polymerase III to join the complex. The down stream element (DSE) of type 3 promoters, which enhances transcription from the core promoter, almost invariably contains an octamer sequence and an SPH element (also called NONOCT element)(Cheung et al., 1993; Danzeiser et al., 1993; Kunkel et al., 1996; Myslinski et al., 1992). The octamer sequence recruits the POU domain protein Oct-1 (Herr et al., 1988; Sturm et al., 1988), and the SPH element recruits a zinc finger protein known as Staf or SPH binding factor (SBF), which has been cloned from humans (Myslinski et al., 1998; Rincon et al., 1998)."
BMGC_PW1623,BMG_PW4283,,,"To facilitate co-transcriptional capping, and thereby restrict the cap structure to RNAs made by RNA polymerase II, the capping enzymes bind directly to the RNA polymerase II. The C-terminal domain of the largest Pol II subunit contains several phosphorylation sites on its heptapeptide repeats. The capping enzyme guanylyltransferase and the methyltransferase bind specifically to CTD phosphorylated at Serine 5 within the CTD. Kinase subunit of TFIIH, Cdk7, catalyzes this phosphorylation event that occurs near the promoter. In addition, it has been shown that binding of capping enzyme to the Serine-5 phosphorylated CTD stimulates guanylyltransferase activity in vitro."
BMGC_PW1624,BMG_PW4284,,,"The second pass through the beta-oxidation spiral starts with the saturated fatty acid myristoyl-CoA (from the first swing through the beta oxidation spiral) and produces lauroyl-CoA. Four enzymatic steps are required starting with LCAD CoA dehydrogenase (Long Chain) activity, followed by three enzymatic steps, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and ketoacyl-CoA thiolase activities, all present in the mitochondrial membrane associated trifunctional protein."
BMGC_PW1625,BMG_PW4285,,,"Once fatty acids have been imported into the mitochondrial matrix by the carnitine acyltransferases, the beta-oxidation spiral begins. Each turn of this spiral concludes with the repetitive removal of two carbon units from the fatty acyl chain. beta-oxidation of saturated fatty acids (fatty acids with even numbered carbon chains and no double bonds) involves four different enzymatic steps: oxidation, hydration, a second oxidation, and a concluding thiolysis step, resulting in the two-carbon acetyl-CoA and a newly CoA primed acyl-CoA for the next turn of the spiral."
BMGC_PW1626,BMG_PW4286,,,"The complete beta-oxidation spiral produces and consumes intermediates with a trans configuration. Mitochondrial beta-oxidation of unsaturated fatty acids leads to intermediates not compatible with the four enzymatic steps responsible for the beta-oxidation of saturated fatty acids. Unsaturated fatty acids that have bonds in the cis configuration require three separate enzymatic steps to prepare these molecules for the beta-oxidation pathway. The further processing of these intermediates requires additional enzymes, depending on the position of the double bonds in the original fatty acids. Described here is the beta-oxidation of linoleoyl-CoA."
BMGC_PW1627,BMG_PW4287,,,"Beta-oxidation begins once fatty acids have been imported into the mitochondrial matrix by carnitine acyltransferases. The beta-oxidation spiral of fatty acids metabolism involves the repetitive removal of two carbon units from the fatty acyl chain. There are four steps to this process: oxidation, hydration, a second oxidation, and finally thiolysis. The last step releases the two-carbon acetyl-CoA and a ready primed acyl-CoA that takes another turn down the spiral. In total each turn of the beta-oxidation spiral produces one NADH, one FADH2, and one acetyl-CoA. Further oxidation of acetyl-CoA via the tricarboxylic acid cycle generates additional FADH2 and NADH. All reduced cofactors are used by the mitochondrial electron transport chain to form ATP. The complete oxidation of a fatty acid molecule produces numerous ATP molecules. Palmitate, used as the model here, produces 129 ATPs. Beta-oxidation pathways differ for saturated and unsaturated fatty acids. The beta-oxidation of saturated fatty acids requires four different enzymatic steps. Beta-oxidation produces and consumes intermediates with a trans configuration; unsaturated fatty acids that have bonds in the cis configuration require three separate enzymatic steps to prepare these molecules for the beta-oxidation pathway."
BMGC_PW1628,BMG_PW4288,,,"This first pass through the beta-oxidation spiral starts with the saturated fatty acid palmitoyl-CoA and produces myristoyl-CoA. Four enzymatic steps are required, starting with VLCAD CoA dehydrogenase (Very Long Chain) activity, followed by three enzymatic steps, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and ketoacyl-CoA thiolase activities, all present in the mitochondrial membrane associated trifunctional protein."
BMGC_PW1629,BMG_PW4289,,,"The third pass through the beta-oxidation spiral picks up where the last left off with the saturated fatty acid lauroyl-CoA and produces decanoyl-CoA. Four enzymatic steps are required starting with LCAD CoA dehydrogenase (Long Chain) activity, followed by the enoyl-CoA hydratase activity of crotonase, the 3-hydroxyacyl-CoA dehydrogenase activity of the short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), and completed by the ketoacyl-CoA thiolase activity, present in the mitochondrial membrane associated trifunctional protein. Note that the 3-hydroxyacyl-CoA dehydrogenase activity of SCHAD is not actually limited to short chain fatty acids, in fact SCHAD has a broad substrate specificity."
BMGC_PW1630,BMG_PW4290,,,"The fourth pass through the beta-oxidation spiral picks up where the last left off with the saturated fatty acid decanoyl-CoA and produces octanoyl-CoA. Four enzymatic steps are required starting with MCAD CoA dehydrogenase (Medium Chain) activity, followed by the enoyl-CoA hydratase activity of crotonase, the 3-hydroxyacyl-CoA dehydrogenase activity of the short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), and completed by the ketoacyl-CoA thiolase activity, present in the mitochondrial membrane associated trifunctional protein. Note that the 3-hydroxyacyl-CoA dehydrogenase activity of SCHAD is not actually limited to short chain fatty acids, in fact SCHAD has a broad substrate specificity."
BMGC_PW1631,BMG_PW4291,,,"The fifth pass through the beta-oxidation spiral picks up where the last left off with the saturated fatty acid octanoyl-CoA and produces hexanoyl-CoA. Four enzymatic steps are required starting with MCAD CoA dehydrogenase (Medium Chain) activity, followed by the enoyl-CoA hydratase activity of crotonase, the 3-hydroxyacyl-CoA dehydrogenase activity of the short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), and completed by the ketoacyl-CoA thiolase activity, present in the mitochondrial membrane associated trifunctional protein."
BMGC_PW1632,BMG_PW4292,,,"The sixth pass through the beta-oxidation spiral picks up where the last left off with the saturated fatty acid hexanoyl-CoA and produces butanoyl-CoA. Four enzymatic steps are required starting with SCAD CoA dehydrogenase (Short Chain) activity, followed by the enoyl-CoA hydratase activity of crotonase, the 3-hydroxyacyl-CoA dehydrogenase activity of the short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), and completed by the ketoacyl-CoA thiolase activity, present in the mitochondrial membrane associated trifunctional protein."
BMGC_PW1633,BMG_PW4294,,,"Triggered by acidification of the endosome, insulin dissociates from the receptor and is degraded. The receptor is dephosphorylated and re-integrated into the plasma membrane, ready to be activated again by the binding of insulin molecules."
BMGC_PW1634,BMG_PW4295,,,The formation of centromeric chromatin assembly outside the context of DNA replication involves the assembly of nucleosomes containing the histone H3 variant CenH3 (also called CENP-A).
BMGC_PW1635,BMG_PW4296,,,"There are two well-documented trans-acting factors required for histone pre-mRNA processing. These are: 1 Stem-loop binding protein (SLBP), also termed hairpin binding protein (HBP). This 32 kDa protein is likely the first protein that binds to the histone pre-mRNA as it is being transcribed. The U7 snRNP. This particle contains the U7 snRNA, the smallest of the snRNAs which varies from 57-70 nts long depending on the species. The 5' end of U7 snRNA binds to a sequence 3' of the stemloop, termed the histone downstream element (HDE). There are a number of proteins found in the U7 snRNP. There are 7 Sm proteins, as are present in the spliceosomal snRNP. Five of these proteins are the same as ones found in the spliceosomal snRNPs and there are 2, Lsm10 and Lsm11 that are unique to U7 snRNP. A third protein joins the U7 snRNP, ZFP100, a large zinc finger protein. ZFP100 interacts with SLBP bound to the histone pre-mRNA and with Lsm11 and likely plays a critical role in recruiting U7 snRNP to the histone pre-mRNA. It should be noted that there must be other trans-acting factors, including the factor that catalyzes the cleavage reaction. The cleavage occurs in the presence of EDTA as does the cleavage reaction in polyadenylation, it is likely that this reaction is catalyzed by a protein. There may well be additional proteins associated with U7 snRNP, and since under some conditions in vitro processing occurs in the absence of SLBP, it is possible that all of the other factors required for processing are associated with the active form of U7 snRNP."
BMGC_PW1636,BMG_PW4297,,,"The 3' ends of eukaryotic mRNAs are generated by posttranscriptional processing of an extended primary transcript. For almost all RNAs, 3' processing consists of two steps: The mRNA is first cleaved at a particular phosphodiester bond downstream of the coding sequence. The upstream fragment then receives a poly(A) tail of approximately 250 adenylate residues whereas the downstream fragment is degraded. The two partial reactions are coupled so that reaction intermediates are usually undetectable. While 3' processing can be studied as an isolated event in vitro, it appears to be connected to transcription, splicing and transcription termination in vivo."
BMGC_PW1637,BMG_PW4298,,,"Long chain fatty acids (LCFAs) are involved in many cellular functions. They can be used as an important source of energy by skeletal muscle and heart tissues. Also, they are used in the production of hormones which can regulate inflammation, blood pressure, the clotting process, blood lipid levels and the immune response. Fatty acid transporter proteins (FATPs) are a family of proteins which mediate fatty acid uptake into cells when overexpressed. FATPs also possess enzymatic activity, the details of which are captured elsewhere. There are 6 human genes of the SLC27A family which encode for FATP1-6 (Stahl A, 2004; Gimeno RE, 2007). To date, only FATP1, 4 and 6 have demonstrable transporter function. Fatty acids with carbon chain lengths of more than 10 are the most likely substrates for these transporters."
BMGC_PW1638,BMG_PW4299,,,"Two families of transport proteins mediate the movement of nucleosides and free purine and pyrimidine bases across the plasma membrane. Equilibrative nucleoside transporters allow the movement of these molecules along concentration gradients into or out of cells (Baldwin et al. 2003); concentrative nucleoside transporters actively transport nucleosides into cells by coupling their transport to the inward movement of sodium ions (Gray et al. 2003). Of the four human equilibrative nucleoside transporters, two are well characterized. SLC29A1 (solute carrier family 29 (nucleoside transporters), member 1) mediates the transport of nucleosides across the plasma membrane. SLC29A2 (solute carrier family 29 (nucleoside transporters), member 2) mediates the transport of both nucleosides and free bases. Transporter specificities were determined by expressing cloned human genes in Xenopus oocytes or in mammalian cultured cell lines whose own nucleotide transporters had been disrupted by mutation. These studies establish that the transport processes are specific and saturable, and that the multiple nucleotides and bases compete for a single binding site on each transporter. Some features of SLC29A2 specificity are complex. For example, in the Xenopus oocyte system, radiolabeled uracil and adenine are taken up, and an excess of either molecule inhibits uptake of radiolabeled hypoxanthine, while in the cultured mammalian cell system, neither adenine nor uracil can inhibit uptake of radiolabeled uridine. If these results reflect ENT2 function in vivo, they indicate that the net movement of a nucleoside or base across the cell membrane is determined not only by its own concentrations in the extracellular space and the cytosol, but also by the concentrations of the other nucleosides and bases competing for access to the transporter. The human genome encodes three concentrative transporters, SLC28A1, 2, and 3 (solute carrier family 28 (sodium-coupled nucleoside transporter), member 1, 2, and 3). All three genes have been cloned, and expression of the human proteins in Xenopus oocytes has allowed their transport properties to be determined. SLC28A1 mediates the uptake of pyrimidine nucleosides and adenosine (Ritzel et al. 1997); SLC28A2 the uptake of purine nucleosides and uridine (Wang et al. 1997); and SLC28A3 the uptake of purine and pyrimidine nucleosides (Ritzel et al. 2001). Amino acid sequence motifs that determine the specificities of these transporters have been identified in studies of chimeric and mutant proteins (Loewen et al. 1999). SLC28A3 protein co-transports two sodium ions per nucleoside; SLC28A1 and 2 transport one sodium per nucleoside (Ritzel et al. 2001). Physiological roles for nucleoside and base transport include provision of nucleosides to cells with little capacity to synthesize these molecules de novo, and regulation of extracellular levels of adenosine, which is released from muscle during intense exercise and has signaling properties. In kidney and intestinal epithelia, the combination of apically localized CNT transporters and basolaterally localized ENT transporters provides a mechanism for net transport of nucleosides (Mangravite et al. 2003). These transporters also mediate the uptake of nucleoside analogs used clinically as anti-viral and anti-tumor drugs. Orthologs of human concentrative and equilibrative transporter proteins have been identified in many eukaryotes, but functional studies of transporters even from organisms closely related to humans (e.g. rat, Gerstin et al. 2002) have revealed differences in substrate specificities. Prediction of drug uptake and other functions of these molecules by human - model organism orthology is thus risky."
BMGC_PW1639,BMG_PW4300,,,"NLRP1 is activated by MDP (Faustin et al. 2007). The NLRP1 inflammasome was the first to be characterized. It was described as a complex containing NALP1, ASC, caspase-1 and caspase-5 (Martinon et al. 2002). Unlike NLRP3, NLRP1 has a C-terminal extension containing a CARD domain, which has been reported to interact directly with procaspase-1, obviating a requirement for ASC (Faustin et al. 2007), though ASC was found to augment the interaction. Mouse NLRP1 has no PYD domain and would therefore not be expected to interact directly with procaspase-1. Like the NLRP3 inflammasome, K+ efflux appears to be essential for caspase-1 activation (Wickliffe et al. 2008). Ribonucleoside triphosphates (NTPs) are required for NALP1-mediated caspase-1 activation with ATP being the most efficient, Mg2+ was also required (Faustin et al. 2007). The human NLRP1 gene has 3 paralogues in mouse that are highly polymorphic. Differences between mouse strains underlie susceptibility to anthrax lethal toxin (Boyden & Dietrich 2006)."
BMGC_PW1640,BMG_PW4301,,,"The NLRP3 (Cryopyrin) inflammasome is currently the best characterized. It consists of NLRP3, ASC (PYCARD) and procaspase-1; CARD8 (Cardinal) is also suggested to be a component. It is activated by a number of pathogens and bacterial toxins as well as diverse PAMPs, danger-associated molecular patterns (DAMPS) such as hyaluronan and uric acid, and exogenous irritants such as silica and asbestos (see Table S1 Schroder & Tschopp, 2010). Mutations in NLRP3 which lead to constitutive activation are linked to the human diseases Muckle-Wells syndrome, familial cold autoinflammatory syndrome and NOMID (Ting et al. 2006), characterized by skin rashes and other symptoms associated with generalized inflammation. The cause of these symptoms is uncontrolled IL-1 beta production. Multiple studies have shown that activation of the NLRP3 inflammasome by particulate activators (e.g. Hornung et al. 2008) requires phagocytosis, but this is not required for the response to ATP, which is mediated by the P2X7 receptor (Kahlenberg & Dubyak, 2004) and appears to involve the pannexin membrane channel (Pellegrin & Suprenenant 2006). Direct binding of activators to NLRP3 has not been demonstrated and the exact process of activation is unclear, though it is speculated to involve changes in conformation that free the NACHT domain for oligomerization (Inohara & Nunez 2001, 2003)."
BMGC_PW1641,BMG_PW4302,,,"AIM2 is a member of the PYHIN or HIN200 family. It has a C-terminal HIN domain which can bind double-stranded DNA (dsDNA) and a PYD domain that can bind ASC via a PYD-PYD interaction. In cells expressing procaspase-1, The interaction of AIM2 with ASC leads to recruitment of procaspase-1 forming the ASC pyroptosome which induces pyroptotic cell death by generating active caspase-1. Data from AIM2 deficient mice indicates that the AIM2 inflammasome is a nonredundant sensor for dsDNA that regulates the caspase-1-dependent maturation of IL-1beta and IL-18 (Rathinam et al. 2010, Hornung & Latz, 2009)."
BMGC_PW1642,BMG_PW4304,,,"Interferon-gamma (IFN-gamma) belongs to the type II interferon family and is secreted by activated immune cells-primarily T and NK cells, but also B-cells and APC. INFG exerts its effect on cells by interacting with the specific IFN-gamma receptor (IFNGR). IFNGR consists of two chains, namely IFNGR1 (also known as the IFNGR alpha chain) and IFNGR2 (also known as the IFNGR beta chain). IFNGR1 is the ligand binding receptor and is required but not sufficient for signal transduction, whereas IFNGR2 do not bind IFNG independently but mainly plays a role in IFNG signaling and is generally the limiting factor in IFNG responsiveness. Both IFNGR chains lack intrinsic kinase/phosphatase activity and thus rely on other signaling proteins like Janus-activated kinase 1 (JAK1), JAK2 and Signal transducer and activator of transcription 1 (STAT-1) for signal transduction. IFNGR complex in its resting state is a preformed tetramer and upon IFNG association undergoes a conformational change. This conformational change induces the phosphorylation and activation of JAK1, JAK2, and STAT1 which in turn induces genes containing the gamma-interferon activation sequence (GAS) in the promoter."
BMGC_PW1643,BMG_PW4305,,,"At least three different classes of negative regulators exist to control the extent of INFG stimulation and signaling. These include the feedback inhibitors belonging to protein family suppressors of cytokine signaling (SOCS), the Scr-homology 2 (SH2)-containing protein tyrosine phosphatases (SHPs), and the protein inhibitors of activated STATs (PIAS). The induction of these regulators seems to be able to stop further signal transduction by inhibiting various steps in IFNG cascade."
BMGC_PW1644,BMG_PW4306,,,"Advanced Glycosylation End- product-specific Receptor (AGER) also known as Receptor for Advanced Glycation End-products (RAGE) is a multi-ligand membrane receptor belonging to the immunoglobulin superfamily. It is considered to be a Pattern Recognition Receptor (Liliensiek et al. 2004). It recognizes a large variety of modified proteins known as advanced glycation/glycosylation endproducts (AGEs), a heterogenous group of structures that are generated by the Maillard reaction, a consequence of long-term incubation of proteins with glucose (Ikeda et al. 1996). Their accumulation is associated with diabetes, atherosclerosis, renal failure and ageing (Schmidt et al. 1999). The most prevalent class of AGE in vivo are N(6)-carboxymethyllysine (NECML) adducts (Kislinger et al. 1991). In addition to AGEs, AGER is a signal transduction receptor for amyloid-beta peptide (Ab) (Yan et al. 1996), mediating Ab neurotoxicity and promoting Ab influx into the brain. AGER also responds to the proinflammatory S100/calgranulins (Hofmann et al. 1999) and High mobility group protein B1 (HMGB1/Amphoterin/DEF), a protein linked to neurite outgrowth and cellular motility (Hori et al. 1995). The major inflammatory pathway stimulated by AGER activation is NFkappaB. Though the signaling cascade is unclear, several pieces of experimental data suggest that activation of AGER leads to sustained activation and upregulation of NFkappaB, measured as NFkappaB translocation to the nucleus, and increased levels of de novo synthesized NFkappaB (Bierhaus et al. 2001). As this is clearly an indirect effect it is represented here as positive regulation of NFkappaB translocation to the nucleus. AGER can bind ERK1/2 and thereby activate the MAPK and JNK cascades (Bierhaus et al. 2005)."
BMGC_PW1645,BMG_PW4307,,,"Organic anion transporting polypeptides (OATPs) are membrane transport proteins that mediate the sodium-independent transport of a wide range of amphipathic organic compounds including bile salts, steroid conjugates, thyroid hormones, anionic oligopeptides and numerous drugs (Hagenbuch B and Meier PJ, 2004)."
BMGC_PW1646,BMG_PW4309,,,"Gastrin is a hormone whose main function is to stimulate secretion of hydrochloric acid by the gastric mucosa, which results in gastrin formation inhibition. This hormone also acts as a mitogenic factor for gastrointestinal epithelial cells. Gastrin has two biologically active peptide forms, G34 and G17.Gastrin gene expression is upregulated in both a number of pre-malignant conditions and in established cancer through a variety of mechanisms. Depending on the tissue where it is expressed and the level of expression, differential processing of the polypeptide product leads to the production of different biologically active peptides. In turn, acting through the classical gastrin cholecystokinin B receptor CCK-BR, its isoforms and alternative receptors, these peptides trigger signalling pathways which influence the expression of downstream genes that affect cell survival, angiogenesis and invasion (Wank 1995, de Weerth et al. 1999, Grabowska & Watson 2007)"
BMGC_PW1647,BMG_PW4311,,,"PTK6 (BRK) is activated downstream of ERBB2 (HER) (Xiang et al. 2008, Peng et al. 2015) and other receptor tyrosine kinases, such as EGFR (Kamalati et al. 1996) and MET (Castro and Lange 2010). However, it is not clear if MET and EGFR activate PTK6 directly or act through ERBB2, since it is known that ERBB2 forms heterodimers with EGFR (Spivak-Kroizman et al. 1992), and MET can heterodimerize with both EGFR and ERBB2 (Tanizaki et al. 2011)."
BMGC_PW1648,BMG_PW4312,,,"PTK6 (BRK) is an oncogenic non-receptor tyrosine kinase that functions downstream of ERBB2 (HER2) (Xiang et al. 2008, Peng et al. 2015) and other receptor tyrosine kinases, such as EGFR (Kamalati et al. 1996) and MET (Castro and Lange 2010). Since ERBB2 forms heterodimers with EGFR and since MET can heterodimerize with both ERBB2 and EGFR (Tanizaki et al. 2011), it is not clear if MET and EGFR activate PTK6 directly or act through ERBB2. Levels of PTK6 increase under hypoxic conditions (Regan Anderson et al. 2013, Pires et al. 2014). The kinase activity of PTK6 is negatively regulated by PTPN1 phosphatase (Fan et al. 2013) and SRMS kinase (Fan et al. 2015), as well as the STAT3 target SOCS3 (Gao et al. 2012). PTK6 activates STAT3-mediated transcription (Ikeda et al. 2009, Ikeda et al. 2010) and may also activate STAT5-mediated transcription (Ikeda et al. 2011). PTK6 promotes cell motility and migration by regulating the activity of RHO GTPases RAC1 (Chen et al. 2004) and RHOA (Shen et al. 2008), and possibly by affecting motility-related kinesins (Lukong and Richard 2008). PTK6 crosstalks with AKT1 (Zhang et al. 2005, Zheng et al. 2010) and RAS signaling cascades (Shen et al. 2008, Ono et al. 2014) and may be involved in MAPK7 (ERK5) activation (Ostrander et al. 2007, Zheng et al. 2012). PTK6 enhances EGFR signaling by inhibiting EGFR down-regulation (Kang et al. 2010, Li et al. 2012, Kang and Lee 2013). PTK6 may also enhance signaling by IGF1R (Fan et al. 2013) and ERBB3 (Kamalati et al. 2000). PTK6 promotes cell cycle progression by phosphorylating and inactivating CDK inhibitor CDKN1B (p27) (Patel et al. 2015). PTK6 activity is upregulated in osteopontin (OPN or SPP1)-mediated signaling, leading to increased VEGF expression via PTK6/NF-kappaB/ATF4 signaling path. PTK6 may therefore play a role in VEGF-dependent tumor angiogenesis (Chakraborty et al. 2008). PTK6 binds and phosphorylates several nuclear RNA-binding proteins, including SAM68 family members (KHDRSB1, KHDRSB2 and KHDRSB3) (Derry et al. 2000, Haegebarth et al. 2004, Lukong et al. 2005) and SFPQ (PSF) (Lukong et al. 2009). The biological role of PTK6 in RNA processing is not known. For a review of PTK6 function, please refer to Goel and Lukong 2015."
BMGC_PW1649,BMG_PW4315,,,"PTK6 enhances EGFR signaling by inhibiting EGFR down-regulation (Kang et al. 2010, Li et al. 2012, Kang and Lee 2013). PTK6 may also enhance signaling by other receptor tyrosine kinases (RTKs), such as IGF1R (Fan et al. 2013) and ERBB3 (Kamalati et al. 2000). PTK6 affects AKT1 activation (Zhang et al. 2005, Zheng et al. 2010) and targets negative regulator of RTKs, DOK1, for degradation (Miah et al. 2014)."
BMGC_PW1650,BMG_PW4316,,,PTK6 promotes cell cycle progression by phosphorylating and inactivating CDK inhibitor CDKN1B (p27) (Patel et al. 2015). PTK6 also negatively modulates CDKN1B expression via regulation of the activity of the FOXO3 (FOXO3A) transcription factor (Chan and Nimnual 2010).
BMGC_PW1651,BMG_PW4317,,,"PTK6 promotes cell motility and migration by regulating the activity of RHO GTPases RAC1 (Chen et al. 2004) and RHOA (Shen et al. 2008). PTK6 inhibits RAS GTPase activating protein RASA1 (Shen et al. 2008) and may be involved in MAPK7 (ERK5) activation (Ostrander et al. 2007, Zheng et al. 2012)"
BMGC_PW1652,BMG_PW4319,,,Levels of PTK6 increase under hypoxic conditions due to direct transcriptional regulation of PTK6 gene by hypoxia inducible transcription factors (HIFs) (Regan Anderson et al. 2013). PTK6 protein levels are also rapidly stabilized in hypoxic conditions in a HIF-independent manner (Pires et al. 2014). It has also been shown that PTK6 is ubiquitinated in normoxic conditions by a so far unknown E3 ligase (Pires et al. 2014).
BMGC_PW1653,BMG_PW4321,,,"Recruitment of receptors and ion channels to the postsynaptic membrane is the last step in synapse formation. Many of these proteins interact directly or indirectly with postsynaptic density-95 (PSD95)/Discs large/zona occludens-1 (PDZ) proteins, thus linking them to the postsynaptic scaffold and providing a mechanism for both retaining the protein at the synapse and keeping its proximity to signaling molecules known to associate with PDZ proteins (Wang et al. 2006, Morimura et al. 2006, Ko et al. 2006, Nourry et al. 2003, Kim & Sheng 2004, Montgomery et al. 2004, Sheng and Kim 2011). The synaptic adhesion-like molecules (SALM) family belongs to the superfamily of leucine-rich repeat (LRR)-containing adhesion molecules, alternatively referred to as LRFN (leucine-rich repeat and fibronectin III domain-containing) is synapse adhesion molecule linked to NMDA and AMPA receptors. It includes five known members (SALMs 1-5 or LRFN1-5), which have been implicated in the regulation of neurite outgrowth and branching, and synapse formation and maturation. SALM proteins are distributed to both dendrites and axons in neurons (Ko et al. 2006, Wang et al. 2006, Sebold et al. 2012). The family members, SALM1-SALM5, have a single transmembrane (TM) domain and contain extracellular leucine-rich repeats, an Ig C2 type domain, a fibronectin type III domain, and an intracellular postsynaptic density-95 (PSD-95)/Discs large/zona occludens-1 (PDZ) binding domain, which is present on all members except SALM4 and SALM5 (Ko et al. 2006, Wang et al.2006, Morimura et al. 2006)."
BMGC_PW1654,BMG_PW4322,,,"The ectonucleoside triphosphate diphosphatase (E-NTPDase family) of ectonucleotidases includes 8 enzymes: NTPDase1 (encoded by the ENTPD1 gene), NTPDase2 (encoded by the ENTPD2 gene), NTPDase3 (encoded by the ENTPD3 gene), NTPDase4 (encoded by the ENTPD4 gene), NTPDase5 (encoded by the ENTPD5 gene), NTPDase6 (encoded by the ENTPD6 gene), NTPDase7 (encoded by the ENTPD7 gene) and NTPDase8 (encoded by the ENTPD8 gene). NTPDases hydrolyze nucleoside triphosphates and nucleoside diphosphates, producing the corresponding nucleoside monophosphates as final products. Different family members show different specificity for particular nucleotides. NTPDases are involved in various biological processes, such as hemostasis, immune response and development of the nervous system. The catalytic domain of NTPDases is contained within the loop formed by a cluster of apyrase conserved regions (ACRs). All family members require divalent cations, such as calcium (Ca2+) or magnesium (Mg2+) ions, for catalytic activity. The hydrolysis involves a nucleophilic attack of a water molecule on the terminal phosphate of a nucleotide substrate. All E-NTPDase family members are transmembrane proteins, associated with either plasma membrane (NTPDase1, NTPDase2, NTPDase3 and NTPDase8) or organelle membranes (NTPDase4 and NTPDase7). Two family members, NTPDase5 and NTPDase6, can be secreted into extracellular space following a proteolytic cleavage from the plasma membrane. NTPDases hydrolyze exocytoplasmic nucleotides, thus regulating the availability of ligands for purinergic receptors. Glycosylation and oligomerization are involved in the regulation of NTPDases, but have not been thoroughly studied. For reviews of the NTPDase family, please refer to Robson et al. 2006 and Zimmermann et al. 2012."
BMGC_PW1655,BMG_PW4323,,,"Butyrophilins (BTNs) and butyrophilin like (BTNL) molecules are regulators of immune responses that belong to the immunoglobulin (Ig) superfamily of transmembrane proteins. They are structurally related to the B7 family of co-stimulatory molecules and have similar immunomodulatory functions (Afrache et al. 2012, Arnett & Viney 2014). BTNs are implicated in T cell development, activation and inhibition, as well as in the modulation of the interactions of T cells with antigen presenting cells and epithelial cells. Certain BTNsare genetically associated with autoimmune and inflammatory diseases (Abeler Domer et al. 2014). The human butyrophilin family includes seven members that are subdivided into three subfamilies: BTN1, BTN2 and BTN3. The BTN1 subfamily contains only the prototypic single copy BTN1A1 gene, whereas the BTN2 and BTN3 subfamilies each contain three genes BTN2A1, BTN2A2 and BTN2A3, and BTN3A1, BTN3A2 and BTN3A3, respectively (note that BTN2A3 is a pseudogene). BTN1A1 has a crucial function in the secretion of lipids into milk (Ogg et al. 2004) and collectively, BTN2 and BTN3 proteins are cell surface transmembrane glycoproteins, that act as regulators of immune responses. BTNL proteins share considerable homology to the BTN family members. The human genome contains four BTNL genes: BTNL2, 3, 8 and 9 (Abeler Domer et al. 2014)."
BMGC_PW1656,BMG_PW4324,,,"A soluble truncated form of FGFR2 is aberrantly expressed in an Apert Syndrome mouse model and inhibits FGFR signaling in vitro and in vivo. This variant, termed FGFR IIIa TM, arises from an misspliced transcript that fuses exon 7 to exon 10 and that escapes nonsense-mediated decay. FGFR2 IIIa TM may inhibit signaling by sequestering FGF ligand and/or by forming nonfunctional heterodimers with full-length receptors at the cell surface (Wheldon et al, 2011)."
BMGC_PW1657,BMG_PW4325,,,"Activated MET receptor recruits the RAS guanyl nucleotide exchange factor (GEF) SOS1 indirectly, either through the GRB2 adapter (Ponzetto et al. 1994, Fournier et al. 1996, Shen and Novak 1997, Besser et al. 1997), GAB1 (Weidner et al. 1996) or SHC1 and GRB2 (Pelicci et al. 1995), or RANBP9 (Wang et al. 2002, Wang et al. 2004). Association of SOS1 with the activated MET receptor complex leads to exchange of GDP to GTP on RAS and activation of RAS signaling (Pelicci et al. 1995, Besser et al. 1997, Shen and Novak 1997, Wang et al. 2004). PTPN11 (SHP2) may contribute to activation of RAS signaling downstream of MET (Schaeper et al. 2000, Furcht et al. 2014). Sustained activation of MAPK1 (ERK2) and MAPK3 (ERK1) downstream of MET-activated RAS may require MET endocytosis and signaling from endosomes (Peschard et al. 2001, Hammond et al. 2001, Petrelli et al. 2002, Kermorgant and Parker 2008). Binding of MET to MUC20 or RANBP10 interferes with RAS activation (Higuchi et al. 2004, Wang et al. 2004)."
BMGC_PW1658,BMG_PW4326,,,"MET binds and phosphorylates the adapter protein GAB1, thus creating a docking site for the regulatory subunit PIK3R1 of the PI3K complex. Recruitment of PI3K to MET-bound phosphorylated GAB1 results in PI3K activation, production of PIP3, and stimulation of downstream AKT signaling (Rodrigues et al. 2000, Schaeper et al. 2000)."
BMGC_PW1659,BMG_PW4327,,,"GTSE1 (B99) was identified as a microtubule-associated protein product of the mouse B99 gene, which exhibits both a cell cycle regulated expression, with highest levels in G2, and DNA damage triggered expression under direct control of TP53 (p53) (Utrera et al. 1998, Collavin et al. 2000). Human GTSE1, similar to the mouse counterpart, binds to microtubules, shows cell cycle regulated expression with a peak in G2 and plays a role in G2 checkpoint recovery after DNA damage but is not transcriptionally regulated by TP53 (Monte et al. 2003, Monte et al. 2004, Scolz et al. 2012). In G1 cells, GTSE1 is found at the microtubule lattice, likely due to direct binding to tubulin. An evolutionarily conserved interaction between GTSE1 and MAPRE1 (EB1), a microtubule plus end protein, promotes GTSE1 localization to the growing tip of the microtubules, which contributes to cell migration and is likely involved in cancer cell invasiveness. Highly invasive breast cancer cell lines exhibit high GTSE1 levels in G1, while GTSE1 levels in G1 are normally low. At the beginning of mitotic prometaphase, GTSE1 is phosphorylated by mitotic kinase(s), possibly CDK1, in proximity to the MAPRE1-binding region, causing GTSE1 dissociation from the plus end microtubule ends (Scolz et al. 2012). During G2 checkpoint recovery (cell cycle re-entry after DNA damage induced G2 arrest), GTSE1 relocates to the nucleus where it binds TP53 and, in an MDM2-dependent manner, promotes TP53 cytoplasmic translocation and proteasome mediated degradation (Monte et al. 2003, Monte et al. 2004). Relocation of GTSE1 to the nucleus in G2 phase depends on PLK1-mediated phosphorylation of GTSE1 (Liu et al. 2010). GTSE1-facilitated down-regulation of TP53 in G2 allows cells to avoid TP53 mediated apoptosis upon DNA damage and to re-enter cell cycle (Monte et al. 2003). While TP53 down-regulation mediated by GTSE1 in G2 correlates with decreased expression of TP53 target genes involved in apoptosis and cell cycle arrest, GTSE1 can also increase the half-life of the TP53 target p21 (CDKN1A). GTSE1-mediated stabilization of CDKN1A involves interaction of GTSE1 with CDKN1A and its chaperone complex, consisting of HSP90 and FKBPL (WISp39), and may be involved in resistance to paclitaxel treatment (Bublik et al. 2010)."
BMGC_PW1660,BMG_PW4330,,,"In recent years, recurrent fusions of FGFR3 have been identified in a number of cancers, including glioblastoma and cancers of the lung and bladder, among others (Singh et al, 2012; Parker et al, 2013; Williams et al, 2013; Wu et al, 2013; Capelletti et al, 2014; Yuan et al, 2014; Wang et al, 2014; Carneiro et al, 2015; reviewed in Parker et al, 2014). The most common fusion partner of FGFR3 is TACC3 (transforming acidic coiled coil protein 3), a protein involved in mitotic spindle assembly and chromosome segregation (Lin et al, 2010; Burgess et al, 2015). FGFR3 fusions are constitutively active and may form oligomers in a ligand-independent manner based on dimerization domains provided by the fusion partner (Singh et al, 2012; Williams et al, 2013; Parker et al, 2013; reviewed in Parker et al, 2014). Transformation and proliferation appear to be promoted through activation of the ERK and AKT signaling pathways. In contrast, PLC gamma signaling is not stimulated downstream of FGFR3 fusions, as the PLC gamma docking site is not present in the fusion. FGFR3 fusions are sensitive to protein kinase inhibitors, suggesting their potential as therapeutic targets (Singh et al, 2012; Williams et al, 2013; Wu et al, 2013; reviewed in Parker et al, 2014)."
BMGC_PW1661,BMG_PW4333,,,"The RET proto-oncogene encodes a receptor tyrosine kinase expressed primarily in urogenital precursor cells, spermatogonocytes, dopaminergic neurons, motor neurons and neural crest progenitors and derived cells. . It is essential for kidney genesis, spermatogonial self-renewal and survivial, specification, migration, axonal growth and axon guidance of developing enteric neurons, motor neurons, parasympathetic neurons and somatosensory neurons (Schuchardt et al. 1994, Enomoto et al. 2001, Naughton et al. 2006, Kramer et al. 2006, Luo et al. 2006, 2009). RET was identified as the causative gene for human papillary thyroid carcinoma (Grieco et al. 1990), multiple endocrine neoplasia (MEN) type 2A (Mulligan et al. 1993), type 2B (Hofstra et al. 1994, Carlson et al. 1994), and Hirschsprung's disease (Romeo et al. 1994, Edery et al. 1994). RET contains a cadherin-related motif and a cysteine-rich domain in the extracellular domain (Takahashi et al. 1988). It is the receptor for members of the glial cell-derived neurotrophic factor (GDNF) family of ligands, GDNF (Lin et al. 1993), neurturin (NRTN) (Kotzbauer et al. 1996), artemin (ARTN) (Baloh et al. 1998), and persephin (PSPN) (Milbrandt et al. 1998), which form a family of neurotrophic factors. To stimulate RET, these ligands need a glycosylphosphatidylinositol (GPI)-anchored co-receptor, collectively termed GDNF family receptor-alpha (GFRA) (Treanor et al. 1996, Jing et al. 1996). The four members of this family have different, overlapping ligand preferences. GFRA1, GFRA2, GFRA3, and GFRA4 preferentially bind GDNF, NRTN, ARTN and PSPN, respectively (Jing et al. 1996, 1997, Creedon et al. 1997, Baloh et al. 1997, 1998, Masure et al. 2000). The GFRA co-receptor can come from the same cell as RET, or from a different cell. When the co-receptor is produced by the same cell as RET, it is termed cis signaling. When the co-receptor is produced by another cell, it is termed trans signaling. Cis and trans activation has been proposed to diversify RET signaling, either by recruiting different downstream effectors or by changing the kinetics or efficacy of kinase activation (Tansey et al. 2000, Paratcha et al. 2001). Whether cis and trans signaling has significant differences in vivo is unresolved (Fleming et al. 2015). Different GDNF family members could activate similar downstream signaling pathways since all GFRAs bind to and activate the same tyrosine kinase and induce coordinated phosphorylation of the same four RET tyrosines (Tyr905, Tyr1015, Tyr1062, and Tyr1096) with similar kinetics (Coulpier et al. 2002). However the exact RET signaling pathways in different types of cells and neurons remain to be determined."
BMGC_PW1662,BMG_PW4335,,,"The protein levels of aurora kinase A (AURKA) during mitotic entry and in early mitosis can be reduced by the action of the SCF-FBXL7 E3 ubiquitin ligase complex consisting of SKP1, CUL1, RBX1 and FBXL7 subunits. FBXL7 is the substrate recognition subunit of the SCF-FBXL7 complex that associates with the centrosome-bound AURKA, promoting its ubiquitination and proteasome-mediated degradation. Overexpression of FBXL7 results in G2/M cell cycle arrest and apoptosis (Coon et al. 2011). FBXL7 protein levels are down-regulated by the action of the SCF-FBXL18 E3 ubiquitin ligase complex, consisting of SKP1, CUL1, RBX1 and the substrate recognition subunit FBXL18. FBXL18 binds to the FQ motif of FBXL7, targeting it for ubiquitination and proteasome-mediated degradation, counteracting its pro-apoptotic activity (Liu et al. 2015). Cell cycle stage-dependency of down-regulation of FBXL7 by FBXL18 is unknown."
BMGC_PW1663,BMG_PW4336,,,"Rab GTPases are peripheral membrane proteins involved in membrane trafficking. Often through their indirect interactions with coat components, motors, tethering factors and SNAREs, the Rab GTPases serve as multifaceted organizers of almost all membrane trafficking processes in eukaryotic cells. To perform these diverse processes, Rab GTPases interconvert between an active GTP-bound form and an inactive, GDP-bound form. The GTP-bound activated form mediates membrane transport through specific interaction with multiple effector molecules (Zerial & McBride 2001, Stenmark 2009, Zhen & Stenmark 2015, Cherfils & Zeghouf 2013). Conversion from the GTP- to the GDP-bound form occurs through GTP hydrolysis, which is not only driven by the intrinsic GTPase activity of the Rab protein but is also catalysed by GTPase-activating proteins (GAPs). GAPs not only increase the rate of GTP hydrolysis, but they are also involved in the inactivation of RABs, making sure they are inactivated at the correct membrane. Human cells contain as many as 70 Rabs and at least 51 putative Rab GAPs (Pfeffer 2005). Only a few of these GAPs have been matched to a specific Rab substrate. The Tre-2/Bub2/Cdc16 (TBC) domain-containing RAB-specific GAPs (TBC/RABGAPs) are a key family of RAB regulators, where the TBC domain facilitates the inactivation of RABs by facilitating activation of GTPase activity of the RAB (Pan et al. 2006, Frasa et al. 2012, Stenmark 2009). Studies suggest that TBC/RABGAPs are more than just negative regulators of RABs and can integrate signalling between RABs and other small GTPases, thereby regulating numerous cellular processes like intracellular trafficking (Frasa et al. 2012)."
BMGC_PW1664,BMG_PW4337,,,"TPX2 binds to aurora kinase A (AURKA) at centrosomes and promotes its activation by facilitating AURKA active conformation and autophosphorylation of the AURKA threonine residue T288 (Bayliss et al. 2003, Xu et al. 2011, Giubettini et al. 2011, Dodson and Bayliss 2012)."
BMGC_PW1665,BMG_PW4339,,,"The interleukin 20 (IL20) subfamily comprises IL19, IL20, IL22, IL24 and IL26. They are members of the larger IL10 family, but have been grouped together based on their usage of common receptor subunits and similarities in their target cell profiles and biological functions. Members of the IL20 subfamily facilitate the communication between leukocytes and epithelial cells, thereby enhancing innate defence mechanisms and tissue repair processes at epithelial surfaces. Much of the understanding of this group of cytokines is based on IL22, which is the most studied member (Rutz et al. 2014, Akdis M et al. 2016, Longsdon et al. 2012)."
BMGC_PW1666,BMG_PW4340,,,"Retrograde traffic from the cis-Golgi to the ERGIC or the ER occurs through either COPI-coated vesicles or through a less well characterized RAB6-dependent route that makes use of tubular carriers (reviewed in Lord et al, 2013; Spang et al, 2013; Heffernan and Simpson, 2014). The balance between these two pathways may be influenced cargo type and concentration and membrane composition, though the details remain to be worked out (reviewed in Heffernan and Simpson, 2014)."
BMGC_PW1667,BMG_PW4341,,,"Recruitment of plasma membrane-localized cargo into clathrin-coated endocytic vesicles is mediated by interaction with a variety of clathrin-interacting proteins collectively called CLASPs (clathrin-associated sorting proteins). CLASP proteins, which may be monomeric or tetrameric, are recruited to the plasma membrane through interaction with phosphoinsitides and recognize linear or conformational sequences or post-translational modifications in the cytoplasmic tails of the cargo protein. Through bivalent interactions with clathrin and/or other CLASP proteins, they bridge the recruitment of the cargo to the emerging clathrin coated pit (reviewed in Traub and Bonifacino, 2013). The tetrameric AP-2 complex, first identified in early studies of clathrin-mediated endocytosis, was at one time thought to be the primary CLASP protein involved in cargo recognition at the plasma membrane, and indeed plays a key role in the endocytosis of cargo carrying dileucine- or tyrosine-based motifs. A number of studies have been performed to test whether AP-2 is essential for all forms of clathrin-mediated endocytosis (Keyel et al, 2006; Motely et al, 2003; Huang et al, 2004; Boucrot et al, 2010; Henne et al, 2010; Johannessen et al, 2006; Gu et al, 2013; reviewed in Traub, 2009; McMahon and Boucrot, 2011). Although depletion of AP-2 differentially affects the endocytosis of different cargo, extensive depletion of AP-2 through RNAi reduces clathrin-coated pit formation by 80-90%, and the CCPs that do form still contain AP-2, highlighting the critcical role of this complex in CME (Johannessen et al, 2006; Boucrot et al, 2010; Henne et al, 2010). In addition to AP-2, a wide range of other CLASPs including proteins of the beta-arrestin, stonin and epsin families, engage sorting motifs in other cargo and interact either with clathrin, AP-2 or each other to facilitate assembly of a clathin-coated pit (reviewed in Traub and Bonifacino, 2013)."
BMGC_PW1668,BMG_PW4342,,,HBEGF-stimulated formation of EGFR heterodimers with GPNMB triggers PTK6-mediated phosphorylation and stabilization of the hypoxia inducible factor 1 alpha (HIF1A) under normoxic conditions. This process depends on the presence of a long non-coding RNA LINC01139 (LINK-A) (Lin et al. 2016).
BMGC_PW1669,BMG_PW4343,,,"Post-mitotic neurons do not have an active cell cycle. However, deregulation of Cyclin Dependent Kinase-5 (CDK5) activity in these neurons can aberrantly activate various components of cell cycle leading to neuronal death (Chang et al. 2012). Random activation of cell cycle proteins has been shown to play a key role in the pathogenesis of several neurodegenerative disorders (Yang et al. 2003, Lopes et al. 2009). CDK5 is not activated by the canonical cyclins, but binds to its own specific partners, CDK5R1 and CDK5R2 (aka p35 and p39, respectively) (Tsai et al. 1994, Tang et al. 1995). Expression of p35 is nearly ubiquitous, whereas p39 is largely expressed in the central nervous system. A variety of neurotoxic insults such as beta-amyloid (A-beta), ischemia, excitotoxicity and oxidative stress disrupt the intracellular calcium homeostasis in neurons, thereby leading to the activation of calpain, which cleaves p35 into p25 and p10 (Lee et al. 2000). p25 has a six-fold longer half-life compared to p35 and lacks the membrane anchoring signal, which results in its constitutive activation and mislocalization of the CDK5:p25 complex to the cytoplasm and the nucleus. There, CDK5:p25 is able to access and phosphorylate a variety of atypical targets, triggering a cascade of neurotoxic pathways that culminate in neuronal death. One such neurotoxic pathway involves CDK5-mediated random activation of cell cycle proteins which culminate in neuronal death. Exposure of primary cortical neurons to oligomeric beta-amyloid (1-42) hyper-activates CDK5 due to p25 formation, which in turn phosphorylates CDC25A, CDC25B and CDC25C. CDK5 phosphorylates CDC25A at S40, S116 and S261; CDC25B at S50, T69, S160, S321 and S470; and CDC25C at T48, T67, S122, T130, S168 and S214. CDK5-mediated phosphorylation of CDC25A, CDC25B and CDC25C not only increases their phosphatase activities but also facilitates their release from 14-3-3 inhibitory binding. CDC25A, CDC25B and CDC25C in turn activate CDK1, CDK2 and CDK4 kinases causing neuronal death. Consistent with this mechanism, higher CDC25A, CDC25B and CDC25C activities were observed in human Alzheimer's disease (AD) clinical samples, as compared to age-matched controls. Inhibition of CDC25 isoforms confers neuroprotection to beta-amyloid toxicity, which underscores the contribution of this pathway to AD pathogenesis"
BMGC_PW1670,BMG_PW4344,,,"Signaling by ERBB2 can be downregulated by ubiquitination and subsequent proteasome-dependent degradation of ERBB2 or activated ERBB2 heterodimers. In addition, protein tyrosine phosphatases that dephosphorylate tyrosine residues in the C-terminus of ERBB2 prevent the recruitment of adapter proteins involved in signal transduction, thus attenuating ERBB2 signaling. STUB1 (CHIP) and CUL5 are E3 ubiquitin ligases that can target non-activated ERBB2 for proteasome-dependent degradation (Xu et al. 2002, Ehrlich et al. 2009). RNF41 (NRDP1) is an E3 ubiquitin ligase that targets ERBB3 and activated heterodimers of ERBB2 and ERBB3 for proteasome-dependent degradation by ubiquitinating ERBB3 (Cao et al. 2007). Two protein tyrosine phosphatases of the PEST family, PTPN12 and PTPN18, dephosphorylate tyrosine residues in the C-terminus of ERBB2, thus preventing signal transduction to RAS and PI3K effectors (Sun et al. 2011, Wang et al. 2014)."
BMGC_PW1671,BMG_PW4345,,,"The AP-2 (TFAP2) family of transcription factors includes five proteins in mammals: TFAP2A (AP-2 alpha), TFAP2B (AP-2 beta), TFAP2C (AP-2 gamma), TFAP2D (AP-2 delta) and TFAP2E (AP-2 epsilon). The AP-2 family transcription factors are evolutionarily conserved in metazoans and are characterized by a helix-span-helix motif at the C-terminus, a central basic region, and the transactivation domain at the N-terminus. The helix-span-helix motif and the basic region enable dimerization and DNA binding (Eckert et al. 2005). AP-2 dimers bind palindromic GC-rich DNA response elements that match the consensus sequence 5'-GCCNNNGGC-3' (Williams and Tjian 1991a, Williams and Tjian 1991b). Transcriptional co-factors from the CITED family interact with the helix-span-helix (HSH) domain of TFAP2 (AP-2) family of transcription factors and recruit transcription co-activators EP300 (p300) and CREBBP (CBP) to TFAP2-bound DNA elements. CITED2 shows the highest affinity for TFAP2 proteins, followed by CITED4, while CITED1 interacts with TFAP2s with a very low affinity. Mouse embryos defective for CITED2 exhibit neural crest defects, cardiac malformations and adrenal agenesis, which can at least in part be attributed to a defective Tfap2 transactivation (Bamforth et al. 2001, Braganca et al. 2002, Braganca et al. 2003). Transcriptional activity of AP-2 dimers in inhibited by binding of KCTD1 or KCTD15 to the AP-2 transactivation domain (Ding et al. 2009, Zarelli and Dawid 2013). Transcriptional activity of TFAP2A, TFAP2B and TFAP2C is negatively regulated by SUMOylation mediated by UBE2I (UBC9) (Eloranta and Hurst 2002, Berlato et al. 2011, Impens et al. 2014, Bogachek et al. 2014). During embryonic development, AP-2 transcription factors stimulate proliferation and suppress terminal differentiation in a cell-type specific manner (Eckert et al. 2005). TFAP2A and TFAP2C directly stimulate transcription of the estrogen receptor ESR1 gene (McPherson and Weigel 1999). TFAP2A expression correlates with ESR1 expression in breast cancer, and TFAP2C is frequently overexpressed in estrogen-positive breast cancer and endometrial cancer (deConinck et al. 1995, Turner et al. 1998). TFAP2A, TFAP2C, as well as TFAP2B can directly stimulate the expression of ERBB2, another important breast cancer gene (Bosher et al. 1996). Association of TFAP2A with the YY1 transcription factor significantly increases the ERBB2 transcription rate (Begon et al. 2005). In addition to ERBB2, the expression of another receptor tyrosine kinase, KIT, is also stimulated by TFAP2A and TFAP2B (Huang et al. 1998), while the expression of the VEGF receptor tyrosine kinase ligand VEGFA is repressed by TFAP2A (Ruiz et al. 2004, Li et al. 2012). TFAP2A stimulates transcription of the transforming growth factor alpha (TGFA) gene (Wang et al. 1997). TFAP2C regulates EGFR in luminal breast cancer (De Andrade et al. 2016). TFAP2C plays a critical role in maintaining the luminal phenotype in human breast cancer and in influencing the luminal cell phenotype during normal mammary development (Cyr et al. 2015). In placenta, TFAP2A and TFAP2C directly stimulate transcription of both subunits of the human chorionic gonadotropin, CGA and CGB (Johnson et al. 1997, LiCalsi et al. 2000). TFAP2A and/or TFAP2C, in complex with CITED2, stimulate transcription of the PITX2 gene, involved in left-right patterning and heart development (Bamforth et al. 2004, Li et al. 2012). TFAP2A and TFAP2C play opposing roles in transcriptional regulation of the CDKN1A (p21) gene locus. While TFAP2A stimulates transcription of the CDKN1A cyclin-dependent kinase inhibitor (Zeng et al. 1997, Williams et al. 2009, Scibetta et al. 2010), TFAP2C represses CDKN1A transcription (Williams et al. 2009, Scibetta et al. 2010, Wong et al. 2012). Transcription of the TFAP2A gene may be inhibited by CREB and E2F1 (Melnikova et al. 2010). For review of the AP-2 family of transcription factors, please refer to Eckert et al. 2005."
BMGC_PW1672,BMG_PW4346,,,"PTPN11 (SHP2), recruited to activated MET receptor through GAB1, is phosphorylated in response to HGF treatment, although phosphorylation sites and direct MET involvement have not been examined (Schaeper et al. 2000, Duan et al. 2006). Phosphorylation of PTPN11 in response to HGF treatment is required for the recruitment and activation of sphingosine kinase SPHK1, which may play a role in HGF-induced cell scattering (Duan et al. 2006). While PTPN11 promotes MAPK3/1 (ERK1/2) signaling downstream of MET, it can also dephosphorylate MET on unidentified tyrosine residues (Furcht et al. 2014)."
BMGC_PW1673,BMG_PW4347,,,"Very low-density lipoprotein (VLDL) is synthesised in the liver in two steps. First, apolipoprotein B-100 (APOB-100) is co- and post-translationally lipidated in the rough ER lumen. After transfer to the smooth ER lumen, lipidated APOB-100 acquires lipids to become bona fide VLDL. Lipid composition of VLDL - triglycerides (50-60%), cholesterol (10-12%), cholesterol esters (4-6%), phospholipids (18-20%), and apolipoprotein B (8-12%). When VLDL assembly is complete, it travels along the Golgi apparatus to be eventually secreted from the liver into general circulation. In circulation, VLDL can acquire more lipoproteins. At least two other apolipoproteins are constituents; apolipoprotein C-I (APOC1, around 20%) and apolipoprotein C4 (APOC4, minor amount) (Gibbons et al. 2004; Olofsson et al. 2000)."
BMGC_PW1674,BMG_PW4348,,,The steps involved in proprotein convertase PCSK9-induced degradation of VLDLR are described here (Poirier et al. 2008). The rate of this catabolic process plays a clinically significant role in determining the efficiency of lipoprotein clearance from the blood.
BMGC_PW1675,BMG_PW4349,,,"Ubiquitin monomers are processed from larger precursors and then activated by formation of a thiol ester bond between ubiquitin and a cysteine residue of an E1 activating enzyme (UBA1 or UBA6, Jin et al. 2007). The ubiquitin is then transferred to the active site cysteine residue of an E2 conjugating enzyme (reviewed in van Wijk and Timmers 2010, Kleiger and Mayor 2014, Stewart et al. 2016). Precursor proteins containing multiple ubiquitin monomers (polyubiquitins) are produced from the UBB and UBC genes. Precursors containing a single ubiquitin fused to a ribosomal protein are produced from the UBA52 and RPS27A genes. The proteases OTULIN and USP5 are very active in polyubiquitin processing, whereas the proteases UCHL3, USP7, and USP9X cleave the ubiquitin-ribosomal protein precursors yielding ubiquitin monomers (Grou et al. 2015). Other enzymes may also process ubiquitin precursors. A resultant ubiquitin monomer is activated by adenylation of its C-terminal glycine followed by conjugation of the C-terminus to a cysteine residue of the E1 enzymes UBA1 or UBA6 via a thiol ester bond (Jin et al. 2007, inferred from rabbit homologues in Haas et al. 1982, Hershko et al. 1983). The ubiquitin is then transferred from the E1 enzyme to a cysteine residue of one of several E2 enzymes (reviewed in van Wijk and Timmers 2010, Stewart et al. 2016)."
BMGC_PW1676,BMG_PW4350,,,"E3 ubiquitin ligases catalyze the transfer of an ubiquitin from an E2-ubiquitin conjugate to a target protein. Generally, ubiquitin is transferred via formation of an amide bond to a particular lysine residue of the target protein, but ubiquitylation of cysteine, serine and threonine residues in a few targeted proteins has also been demonstrated (reviewed in McDowell and Philpott 2013, Berndsen and Wolberger 2014). Based on protein homologies, families of E3 ubiquitin ligases have been identified that include RING-type ligases (reviewed in Deshaies et al. 2009, Metzger et al. 2012, Metzger et al. 2014), HECT-type ligases (reviewed in Rotin et al. 2009, Metzger et al. 2012), and RBR-type ligases (reviewed in Dove et al. 2016). A subset of the RING-type ligases participate in CULLIN-RING ligase complexes (CRLs which include SCF complexes, reviewed in Lee and Zhou 2007, Genschik et al. 2013, Skaar et al. 2013, Lee et al. 2014). Some E3-E2 combinations catalyze mono-ubiquitination of the target protein (reviewed in Nakagawa and Nakayama 2015). Other E3-E2 combinations catalyze conjugation of further ubiquitin monomers to the initial ubiquitin, forming polyubiquitin chains. (It may also be possible for some E3-E2 combinations to preassemble polyubiquitin and transfer it as a unit to the target protein.) Ubiquitin contains several lysine (K) residues and a free alpha amino group to which further ubiquitin can be conjugated. Thus different types of polyubiquitin are possible: K11 linked polyubiquitin is observed in endoplasmic reticulum-associated degradation (ERAD), K29 linked polyubiquitin is observed in lysosomal degradation, K48 linked polyubiquitin directs target proteins to the proteasome for degradation, whereas K63 linked polyubiquitin generally acts as a scaffold to recruit other proteins in several cellular processes, notably DNA repair (reviewed in Komander et al. 2009)."
BMGC_PW1677,BMG_PW4351,,,"Transcriptional activity of TFAP2 (AP-2) transcription factor family homo- and heterodimers in inhibited by binding of KCTD1 or KCTD15 to the AP-2 transactivation domain (Ding et al. 2009, Zarelli and Dawid 2013). Transcriptional activity of TFAP2A, TFAP2B and TFAP2C is also negatively regulated by SUMOylation mediated by UBE2I (UBC9) (Eloranta and Hurst 2002, Berlato et al. 2011, Impens et al. 2014, Bogachek et al. 2014). Binding of the tumor suppressor WWOX to TFAP2C inhibits TFAP2C translocation to the nucleus (Aqeilan et al. 2004). Transcription of the TFAP2A gene may be inhibited by CREB and E2F1 (Melnikova et al. 2010)."
BMGC_PW1678,BMG_PW4353,,,"The helix-span-helix motif and the basic region of TFAP2 (AP-2) transcription factor family members TFAP2A, TFAP2B, TFAP2C, TFAP2D and TFAP2E enable dimerization and DNA binding. AP-2 dimers bind palindromic GC-rich DNA response elements that match the consensus sequence 5'-GCCNNNGGC-3' (Williams and Tjian 1991a, Williams and Tjian 1991b). Most of the AP-2 binding sites slightly differ from the consensus, and individual AP-2 family members may differ in their binding site preferences (McPherson and Weigel 1999, Orso et al. 2010). Transcriptional co-factors from the CITED family interact with the helix-span-helix (HSH) domain of TFAP2 (AP-2) family of transcription factors and recruit transcription co-activators EP300 (p300) and CREBBP (CBP) to TFAP2-bound DNA elements. CITED2 shows the highest affinity for TFAP2 proteins, followed by CITED4, while CITED1 interacts with TFAP2s with a very low affinity. Mouse embryos defective for CITED2 exhibit neural crest defects, cardiac malformations and adrenal agenesis, which can at least in part be attributed to a defective Tfap2 transactivation (Bamforth et al. 2001, Braganca et al. 2002, Braganca et al. 2003). DNA binding and transcriptional activity of TFAP2B homodimers is increased by binding to YEATS4 (GAS41) (Ding et al. 2006)."
BMGC_PW1679,BMG_PW4354,,,"TFAP2A and TFAP2C directly stimulate transcription of the estrogen receptor ESR1 gene (McPherson and Weigel 1999). TFAP2A expression correlates with ESR1 expression in breast cancer, and TFAP2C is frequently overexpressed in estrogen-positive breast cancer and endometrial cancer (deConinck et al. 1995, Turner et al. 1998). TFAP2A, TFAP2C, as well as TFAP2B can directly stimulate the expression of ERBB2, another important breast cancer gene (Bosher et al. 1996). Association of TFAP2A with the YY1 transcription factor significantly increases the ERBB2 transcription rate (Begon et al. 2005). In addition to ERBB2, the expression of another receptor tyrosine kinase, KIT, is also stimulated by TFAP2A and TFAP2B (Huang et al. 1998), while the expression of the VEGF receptor tyrosine kinase ligand VEGFA is repressed by TFAP2A (Ruiz et al. 2004, Li et al. 2012). TFAP2A stimulates transcription of the transforming growth factor alpha (TGFA) gene (Wang et al. 1997). TFAP2C regulates EGFR expression in luminal breast cancer (De Andrade et al. 2016). In placenta, TFAP2A and TFAP2C directly stimulate transcription of both subunits of the human chorionic gonadotropin, CGA and CGB (Johnson et al. 1997, LiCalsi et al. 2000)."
BMGC_PW1680,BMG_PW4355,,,"TFAP2A and TFAP2C play opposing roles in transcriptional regulation of the CDKN1A (p21) gene locus. While TFAP2A stimulates transcription of the CDKN1A cyclin-dependent kinase inhibitor (Zeng et al. 1997, Williams et al. 2009, Scibetta et al. 2010), TFAP2C, in cooperation with MYC and histone demethylase KDM5B, represses CDKN1A transcription (Williams et al. 2009, Scibetta et al. 2010, Wong et al. 2012)."
BMGC_PW1681,BMG_PW4356,,,Mitochondrial ribosomes contain 16S rRNA (large subunit) and 12S rRNA (small subunit) that are encoded in the mitochondrial genome and produced by processing of a long H strand transcript (reviewed in Van Haute et al. 2015). Enzymes encoded in the nucleus and acting in the mitochondrial matrix modify 5 nucleotides in the 12S RNA and 4 nucleotides in the 16S rRNA (reviewed in Van Haute et al. 2015).
BMGC_PW1682,BMG_PW4357,,,"Each eukaryotic cytosolic ribosome contains 4 molecules of RNA: 28S rRNA (25S rRNA in yeast), 5.8S rRNA, and 5S rRNA in the 60S subunit and 18S rRNA in the 40S subunit. The 18S rRNA, 5.8S rRNA, and 28S rRNA are produced by endonucleolytic and exonucleolytic processing of a single 47S precursor (pre-rRNA) (reviewed in Henras et al. 2015). Transcription of ribosomal RNA genes, processing of pre-rRNA, modification of nucleotide residues within the rRNA, and assembly of precursor 60S and 40S subunits occur predominantly in the nucleolus (reviewed in Hernandez-Verdun et al. 2010, Boschi-Muller and Motorin 2013), with a few late reactions occurring in the cytosol."
BMGC_PW1683,BMG_PW4358,,,"During retinoic acid-induced cell differentiation, TFAP2A, in complex with NPM1 (nucleophosmin), represses transcription of HSPD1 (Hsp60), NOP2 (p120) and MYBL2 (b-Myb). The repression of gene expression probably involves the recruitment of histone deacetylases HDAC1 and HDCA2 to target promoters by NPM1. The complex of TFAP2A and NPM1 can also be detected at the NPM1 promoter, which is in agreement with decreased NPM1 expression after retinoic acid treatment. The level of TFAP2A increases in response to the retinoic acid treatment (Liu et al. 2007). NOP2 and MYBL2 are both proliferation markers (Valdez et al. 1992, Saville and Watson 1998)."
BMGC_PW1684,BMG_PW4359,,,"Human cells have more than 60 RAB proteins that are involved in trafficking of proteins in the endolysosomal system. These small GTPases contribute to trafficking specificity by localizing to the membranes of different endocytic compartments and interacting with effectors such as sorting adaptors, tethering factors, kinases, phosphatases and tubular-vesicular cargo (reviewed in Stenmark et al, 2009; Wandinger-Ness and Zerial, 2014). RAB localization depends on a number of factors including C-terminal prenylation, the sequence of an upstream hypervariable regions and what nucleotide is bound (Chavrier et al, 1991; Ullrich et al, 1993; Soldati et al, 1994; Farnsworth et al, 1994; Seabra, 1996; Wu et al, 2010; reviewed in Stenmark, 2009; Wandinger-Ness and Zerial, 2014). In the active, GTP-bound form, prenylated RAB proteins are membrane associated, while in the inactive GDP-bound form, RABs are extracted from the target membrane and exist in a soluble form in complex with GDP dissociation inhibitors (GDIs) (Ullrich et al, 1993; Soldati et al, 1994; Gavriljuk et al, 2103). Conversion between the inactive and active form relies on the activities of RAB guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs) (Yoshimura et al, 2010; Wu et al, 2011; Pan et al, 2006; Frasa et al, 2012; reviewed in Stenmark, 2009; Wandinger-Ness and Zerial, 2014). Newly synthesized RABs are bound by a RAB escort protein, CHM (also known as REP1) or CHML (REP2) (Alexandrov et al, 1994; Shen and Seabra, 1996). CHM/REP proteins are the substrate-binding component of the trimeric RAB geranylgeranyltransferase enzyme (GGTaseII) along with the two catalytic subunits RABGGTA and RABGGTB (reviewed in Gutkowska and Swiezewska, 2012; Palsuledesai and Distefano, 2015). REP proteins recruit the unmodified RAB in its GDP-bound state to the GGTase for sequential geranylgeranylation at one or two C-terminal cysteine residues (Alexandrov et al, 1994; Seabra et al 1996; Shen and Seabra, 1996; Baron and Seabra, 2008). After geranylgeranylation, CHM/REP proteins remain in complex with the geranylgeranylated RAB and escort it to its target membrane, where its activity is regulated by GAPs, GEFs, GDIs and membrane-bound GDI displacement factors (GDFs) (Sivars et al, 2003; reviewed in Stenmark, 2009; Wandinger-Ness and Zerial, 2014)."
BMGC_PW1685,BMG_PW4360,,,"MET receptor activates the focal adhesion kinase PTK2 (FAK1) in a process that depends on the simultaneous interaction of PTK2 with integrins and with MET. SRC is needed for PTK2 to become fully active. Activation of PTK2 is needed for HGF-induced cell motility (Beviglia et al. 1999, Parr et al. 2001, Chen and Chen 2006, Lietha et al. 2007, Chen et al. 2011, Brami-Cherrier et al. 2014)."
BMGC_PW1686,BMG_PW4363,,,"InlB, a cell wall protein of Listeria monocytogenes, binds MET receptor, acting as an HGF agonist (Shen et al. 2000, Veiga and Cossart 2005). Listeria monocytogenes InlB proteins dimerize through their leucine-rich repeat regions (LRRs), promoting dimerization of MET receptors that they are bound to (Ferraris et al. 2010). InlB-induced MET receptor dimerization is followed by MET trans-autophosphorylation and activation of downstream RAS/RAF/MAPK signaling and PI3K/AKT signaling (Niemann et al. 2007, Ferraris et al. 2010). InlB-bound phosphorylated MET receptor recruits the E3 ubiquitin ligase CBL through GRB2. CBL-mediated monoubiquitination of InlB-bound MET promotes endocytosis and entry of Listeria monocytogenes to host cells (Veiga and Cossart 2005). CIN85 is necessary for endocytosis-mediated entry of Listeria monocytogenes triggered by CBL-mediated monoubiquitination of MET (Veiga and Cossart 2005). Proteins involved in clathrin-mediated endocytosis EPS15 and HGS (Hrs) are both necessary for CBL and MET-mediated entry of Listeria monocytogenes into host cells (Veiga and Cossart 2005). A potential coreceptor role of CD44 in InlB-mediated MET activation is contradictory (Jung et al. 2009, Dortet et al. 2010)."
BMGC_PW1687,BMG_PW4364,,,"Interaction of MET with tensin protein TNS4 at focal adhesion sites promotes cell motility through and unknown mechanism. MET also interacts with TNS3, whose expression seems to be inversely correlated with TNS4 (Muharram et al. 2014)."
BMGC_PW1688,BMG_PW4365,,,"The adapter protein GAB1 is involved in recruitment, through CRK and related CRKL proteins, of guanyl nucleotide exchange factors (GEFs) to the activated MET receptor. MET-associated GEFs, such as RAPGEF1 (C3G) and DOCK7, activate RAP1 and RAC1, respectively, leading to morphological changes that contribute to cell motility (Schaeper et al. 2000, Sakkab et al. 2000, Lamorte et al. 2002, Watanabe et al. 2006, Murray et al. 2014)."
BMGC_PW1689,BMG_PW4366,,,"Activated MET receptor is subject to recycling from the plasma membrane through the endosomal compartment and back to the plasma membrane (Peschard et al. 2001, Hammond et al. 2001, Petrelli et al. 2002). In the recycling process, activated MET receptor is endocytosed, and the GGA3 protein directs it, via a largely unknown mechanism, through the RAB4 positive endosomal compartments back to the plasma membrane (Parachoniak et al. 2011). Endosomal signaling by MET during the recycling process appears to play an important role in sustained activation of ERK1/ERK2 (MAPK3/MAPK1) and STAT3 downstream of MET (Kermorgant and Parker 2008)."
BMGC_PW1690,BMG_PW4367,,,"The STAT3 transcription factor binds to activated MET through phosphorylated tyrosine residue Y1356 of MET. STAT3 may also bind to activated MET indirectly through GAB1, but this interaction has not been studied in detail. Activated MET induces phosphorylation of STAT3 at Y705, triggering STAT3 dimerization and nuclear translocation (Schaper et al. 1997, Boccaccio et al. 1998, Zhang et al. 2002, Cramer et al. 2005). Endocytosis of MET and interaction with STAT3 at endosomes may be required for sustained STAT3 phosphorylation in response to HGF stimulation (Kermorgant and Parker 2008). Activated SRC may also contribute to phosphorylation of STAT3 at Y705. STAT3 may promote HGF transcription in a SRC-dependent way, but this autocrine HGF loop may be limited to breast cancer cells (Wojcik et al. 2006, Sam et al. 2007). MET-mediated activation of STAT3 is implicated in anchorage independent cell growth and invasiveness downstream of HGF (Zhang et al. 2002, Cramer et al. 2005). MET can also interact with STAT1A, STAT1B and STAT5, but the biological importance of these interactions is not known (Runge et al. 1999)."
BMGC_PW1691,BMG_PW4368,,,"Direct and indirect interactions of MET with integrins, focal adhesion kinase PTK2 (FAK1), tensin-4 (TNS4) and GTPases RAP1 and RAC1, induce morphological changes that promote cell motility and play an important role in HGF-induced invasiveness of cancer cells (Weidner et al. 1993, Beviglia et al. 1999, Sakkab et al. 2000, Parr et al. 2001, Trusolino et al. 2001, Lamorte et al. 2002, Chen and Chen 2006, Watanabe et al. 2006, Muharram et al. 2014, Murray et al. 2014)."
BMGC_PW1692,BMG_PW4369,,,"Human cells have more than 60 RAB proteins that are key regulators of intracellular membrane trafficking. These small GTPases contribute to trafficking specificity by localizing to the membranes of different organelles and interacting with effectors such as sorting adaptors, tethering factors, kinases, phosphatases and tubular-vesicular cargo (reviewed in Stenmark et al, 2009; Wandinger-Ness and Zerial, 2014; Zhen and Stenmark, 2015). RAB localization depends on a number of factors including C-terminal prenylation, the sequence of upstream hypervariable regions and what nucleotide is bound, as well as interaction with RAB-interacting proteins (Chavrier et al, 1991; Ullrich et al, 1993; Soldati et al, 1994; Farnsworth et al, 1994; Seabra, 1996; Wu et al, 2010; reviewed in Stenmark, 2009; Wandinger-Ness and Zerial, 2014). More recently, the activity of RAB GEFs has also been implicated in regulating the localization of RAB proteins (Blumer et al, 2103; Schoebel et al, 2009; Cabrera and Ungermann, 2013; reviewed in Barr, 2013; Zhen and Stenmark, 2015) In the active, GTP-bound form, RAB proteins are membrane-associated, while in the inactive GDP-bound form, RABs are extracted from the target membrane and exist in a soluble form in complex with GDP dissociation inhibitors (GDIs) (Ullrich et al, 1993; Soldati et al, 1994; Gavriljuk et al, 2013). Conversion between the inactive and active form relies on the activities of RAB guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs) (Yoshimura et al, 2010; Wu et al, 2011; Pan et al, 2006; Frasa et al, 2012; reviewed in Stenmark, 2009; Wandinger-Ness and Zerial, 2014; Ishida et al, 2016). Newly synthesized RABs are bound to a RAB escort protein, CHM (also known as REP1) or CHML (REP2) (Alexandrov et al, 1994; Shen and Seabra, 1996). CHM/REP proteins are the substrate-binding component of the trimeric RAB geranylgeranyltransferase enzyme (GGTaseII) along with the two catalytic subunits RABGGTA and RABGGTB (reviewed in Gutkowska and Swiezewska, 2012; Palsuledesai and Distefano, 2015). REP proteins recruit the unmodified RAB in its GDP-bound state to the GGTase for sequential geranylgeranylation at one or two C-terminal cysteine residues (Alexandrov et al, 1994; Seabra et al 1996; Shen and Seabra, 1996; Baron and Seabra, 2008). After geranylation, CHM/REP proteins remain in complex with the geranylated RAB and escort it to its target membrane, where RAB activity is regulated by GAPs, GEFs, GDIs and membrane-bound GDI displacement factors (GDFs) (Sivars et al, 2003; reviewed in Stenmark, 2009; Wandinger-Ness and Zerial, 2014). Unlike the RAB GAPS, which (to date) all contain a shared TBC domain, RAB GEFs are structurally diverse and range from monomeric to multisubunit complexes (reviewed in Fukuda et al, 2011; Frasa et al, 2012; Cherfils and Zeghouf, 2013; Ishida et al, 2016). While many GEFs contain one of three conserved GEF domains identified to date - the DENN (differentially expressed in normal and neoplastic cell) domain, the VPS9 domain and the SEC2 domain- other GEFs lack a conserved domain (reviewed in Ishida et al, 2016). Based on sequence conservation and subunit organization, GEFs can be grouped into 6 general classes: the DENND-containing GEFs, the VPS9-containing GEFs (both monomeric), the SEC2-containing GEFs (homodimeric), heterodimeric GEF complexes such as RIC1:RGP1, the multisubunit TRAPPC GEF, and others (reviewed in Barr and Lambright, 2010; Marat et al, 2011; Ishida et al, 2016). GEFs for many RABs have still not been identified, however."
BMGC_PW1693,BMG_PW4370,,,"Listeria monocytogenes is a short, gram-positive, nonspore-forming motile rod. Serotypes 1/2a, 1/2b and 4b make up more than 95% of isolates from humans, with serotype 4b causing most of the food-borne outbreaks. Listeria monocytogenes enters the body through the gastrointestinal tract after ingestion of contaminated food. The bacteria can survive food preservation procedures, such as refrigeration, low pH and high salt. Listeria monocytogenes expresses several adhesin proteins at the cell surface that facilitate bacterial binding and entry to host cells. The bacteria can enter host cells through endocytosis mediated by binding of the bacterial InlA (internalin) protein to CDH1 (E-cadherin) at the host cell plasma membrane. Listeria monocytogenes can also enter host cells through endocytosis mediated by binding of the bacterial InlB protein to MET receptor tyrosine kinase at the host cell plasma membrane. Listeria monocytogenes proliferates inside the host cells and triggers formation of filopods, elongated protrusions of the host plasma membrane that contain bacteria. Filopods are ingested by adjacent cells, allowing Listeria monocytogenes to spread from cell to cell, invisible to the immune system of the host. Listeria monocytogenes can cross the intestinal, blood-brain and placental barriers. In immunocompetent adults Listeria monocytogenes infection usually causes gastroenteritis. In infants infected in utero and in immunocompromised adults Listeria monocytogenes infection can result in meningoencephalitis and bacteremia (sepsis). InlA is critical for crossing the intestinal barrier while both InlA and InlB are needed for crossing the placental barrier (Gessain et al. 2015) and, based on in vitro studies, the blood-cerebrospinal fluid barrier (Grundler et al. 2013). It seems that the intrinsic level of PI3K activity in Listeria-targeted host cells determines whether the entry depends on InlA only or InlA and InlB. The interaction of InlA with E-cadherin does not activate PI3K/AKT signaling while the interaction of InlB with the MET receptor activated the PI3K/AKT signal transduction cascade. Therefore, InlB-MET interaction may be important in tissues with low intrinsic PI3K activity (Gessain et al. 2015). Even if InlA-E-cadherin route is sufficient for bacterial entry, InlB may accelerate bacterial invasion (Pentecost et al. 2010). Cholesterol levels in host cell plasma membrane may also influence the preferred route for bacterial endocytosis (Seveau et al. 2004). In addition to InlA and InlB, many other virulence factors are involved in the Listeria monocytogenes infection cycle (Camejo et al. 2011) and will be annotated as mechanistic details become available. For review, please refer to Bonazzi et al. 2009, Brooks et al. 2010, Camejo et al. 2011, Pizarro-Cerda et al. 2012."
BMGC_PW1694,BMG_PW4371,,,"The pathogenic bacteria Listeria monocytogenes can enter host cells through endocytosis triggered by binding of the bacterial cell wall protein internalin (InlA) to the E-cadherin (CDH1) complex at the host cell plasma membrane (Mengaud et al. 1996, Lecuit et al. 1999). Binding of InlA to CDH1, similar to CDH1 engagement during normal cell-to-cell adhesion, triggers activation of the SRC protein tyrosine kinase and phosphorylation of CDH1 and CDH1-bound beta-catenin (CTNNB1) (Fujita et al. 2002, McLachlan et al. 2007, Sousa et al. 2007, Bonazzi et al. 2008). Integrins likely contribute to CDH1-triggered SRC activation, and ERKs (MAPK1 and MAPK3), ROCKs and MLCK may also be involved (Avizienyte et al. 2002, Avizienyte et al. 2004, Martinez-Rico et al. 2010). FAK1 (PTK2), a SRC-regulated protein tyrosine kinase, may contribute to SRC-mediated regulation of CDH1 (Avizienyte et al. 2002). Phosphorylation of CDH1 and CTNNB1 by SRC creates docking sites for a CBL-like ubiquitin protein ligase Hakai (CBLL1). CBLL1 ubiquitinates SRC-phosphorylated CDH1 and CTNNB1 upon InlA binding, as well as in the context of CDH1-mediated cell-to-cell adhesion, thus triggering CDH1 endocytosis (Fujita et al. 2002, Bonazzi et al. 2008, Mukherjee et al. 2012). CBLL1 may also undergo SRC-mediated phosphorylation and subsequent autoubiquitination (Fujita et al. 2002). Both clathrin-mediated and caveolin-mediated endocytosis are implicated in the InlA-mediated entry of Listeria monocytogenes to host cells (Veiga et al. 2007). SRC-mediated phosphorylation of cortactin and the ARP2/3 complex involved in actin polymerization is implicated in CDH1 endocytosis and Listeria monocytogenes internalization (Sousa et al. 2007, Ren et al. 2009)."
BMGC_PW1695,BMG_PW4372,,,"Methylation of lysine (Lys) and arginine (Arg) residues on non-histone proteins is a prevalent post-translational modification and important regulator of cellular signal transduction pathways including MAPK, WNT, BMP, Hippo and JAK–STAT. Crosstalk between methylation and other types of post-translational modifications and between histone and non-histone protein methylation is frequent, affecting cellular functions such as chromatin remodelling, gene transcription, protein synthesis, signal transduction and DNA repair (Biggar & Li 2015)."
BMGC_PW1696,BMG_PW4378,,,"GABA synthesized uniquely by two forms of glutamate decarboxylases, GAD65 and GAD67, that are functionally distinct and have different co-factor requirements. GAD65 is functionally linked to VGAT, the GABA transporter and selectively GABA synthesized by GAD65 is preferably loaded into the synaptic vesicles. GABA synthesized by GAD67 may be used for functions other than nuerotransmission."
BMGC_PW1697,BMG_PW4379,,,Reuptake of GABA from the synapse terminates the action of GABA thus regulating GABA action. GABA taken up from the synapse into the neurons is reused for synaptic loading. GABA taken up by astrocytes is degraded into C02 and glutamine. Glutamine is transported into the neurons for glutamate and GABA synthesis.
BMGC_PW1698,BMG_PW4407,,,"The C-propeptides of collagen propeptide chains are essential for the association of three peptide chains into a trimeric but non-helical procollagen. This initial binding event determines the composition of the trimer, brings the individual chains into the correct register and initiates formation of the triple helix at the C-terminus, which then proceeds towards the N-terminus in a zipper-like fashion (Engel & Prockop 1991). Most early refolding studies were performed with collagen type III, which contains a disulfide linkage at the C-terminus of its triple helix (Bächinger et al. 1978, Bruckner et al. 1978) that acts as a permanent linker even after removal of the non-collagenous domains. Mutations within the C-propeptides further suggest that they are crucial for the correct interaction of the three polypeptide chains and for subsequent correct folding (refs. in Boudko et al. 2011)."
BMGC_PW1699,BMG_PW4451,,,"The synthesis and breakdown of fatty acids are a central part of human energy metabolism, and the eicosanoid class of fatty acid derivatives regulate diverse processes in the body (Vance & Vance 2008 - URL). Processes annotated in this module include the synthesis of fatty acids from acetyl-CoA, mitochondrial and peroxisomal breakdown of fatty acids, and the metabolism of eicosanoids and related molecules."
BMGC_PW1700,BMG_PW4473,,,"Proteins that are released from the CNX or CRT complex with folding defects accumulate in a compartment of the ER called ERQC (Kamhi-Nesher et al. 2001). Here, the enzymes UGGG1 or UGGG2 are able to recognize glycoproteins with minor folding process and re-add the glucose on the alpha,1,3 branch; this is a signal for the transport of these glycoproteins back to the ER, where they can interact again with CNX or CRT in order to achieve a correct folding. At the same time that the glycoprotein is in the ERQC, the enzyme ER mannosidase I progressively removes the mannoses at positions 1A, 2A, B, C on N-glycans; when the mannose on 1A is trimmed, UDP-Glc:glycoprotein glucosyltransferases 1 and 2 (UGGT1 and 2) are no longer able to re-add the glucose, and therefore the protein is destined for ERAD. Glycoproteins subject to endoplasmic reticulum-associated degradation (ERAD) undergo reglucosylation, deglucosylation, and mannose trimming to yield Man6GlcNAc2 and Man5GlcNAc2. These structures lack the mannose residue that is the acceptor of glucose transferred by UGGT1 and 2. For years it has been thought that the removal of the mannose in position B of the N-glycan was the signal to direct proteins to degradation. However, this mechanism has been described better by Avezov et al (Avezov et al. 2008) and it has been demonstrated that even glycoproteins with Man8 or Man7 glycans can be re-glucosylated and interact again with CNX or CRT (for a review on this topic, see Lederkremer 2009 and Maattanen P et al, 2010)."
BMGC_PW1701,BMG_PW4474,,,"The unfolded protein is recognized by a chaperon protein (calnexin or calreticulin) and the folding process starts. The binding of these protein requires a mono-glucosylated glycan (Caramelo JJ and Parodi AJ, 2008) and lectin-based interaction with client proteins is the predominant contributor to chaperone activity of calreticulin (inferred from the mouse homolog in Lum et al. 2016)."
BMGC_PW1702,BMG_PW4569,,,"Type I interferons (IFNs) are composed of various genes including IFN alpha (IFNA), beta (IFNB), omega, epsilon, and kappa. In humans the IFNA genes are composed of more than 13 subfamily genes, whereas there is only one IFNB gene. The large family of IFNA/B proteins all bind to a single receptor which is composed of two distinct chains: IFNAR1 and IFNAR2. The IFNA/B stimulation of the IFNA receptor complex leads to the formation of two transcriptional activator complexes: IFNA-activated-factor (AAF), which is a homodimer of STAT1 and IFN-stimulated gene factor 3 (ISGF3), which comprises STAT1, STAT2 and a member of the IRF family, IRF9/P48. AAF mediates activation of the IRF-1 gene by binding to GAS (IFNG-activated site), whereas ISGF3 activates several IFN-inducible genes including IRF3 and IRF7."
BMGC_PW1703,BMG_PW4570,,,"Meiotic recombination exchanges segments of duplex DNA between chromosomal homologs, generating genetic diversity (reviewed in Handel and Schimenti 2010, Inagaki et al. 2010, Cohen et al. 2006). There are two forms of recombination: non-crossover (NCO) and crossover (CO). In mammals, the former is required for correct pairing and synapsis of homologous chromosomes, while CO intermediates called chiasmata are required for correct segregation of bivalents. Meiotic recombination is initiated by double-strand breaks created by SPO11, which remains covalently attached to the 5' ends after cleavage. SPO11 is removed by cleavage of single DNA strands adjacent to the covalent linkage. The resulting 5' ends are further resected to produce protruding 3' ends. The single-stranded 3' ends are bound by RAD51 and DMC1, homologs of RecA that catalyze a search for homology between the bound single strand and duplex DNA of the chromosomal homolog. RAD51 and DMC1 then catalyze the invasion of the single strand into the homologous duplex and the formation of a D-loop heteroduplex. Approximately 90% of heteroduplexes are resolved without crossovers (NCO), probably by synthesis-dependent strand annealing. The invasive strand is extended along the homolog and ligated back to its original duplex, creating a double Holliday junction. The mismatch repair proteins MSH4, MSH5 participate in this process, possibly by stabilizing the duplexes. The mismatch repair proteins MLH1 and MLH3 are then recruited to the double Holliday structure and an unidentified resolvase (Mus81? Gen1?) cleaves the junctions to yield a crossover. Crossovers are not randomly distributed: The histone methyltransferase PRDM9 recruits the recombination machinery to genetically determined hotspots in the genome and each incipient crossover somehow inhibits formation of crossovers nearby, a phenomenon called crossover interference. Each chromosome bivalent, including the X-Y body in males, has at least one crossover and this is required for meiosis to proceed correctly. For review, please refer to Cohen et al. 2006, Inagaki et al. 2010, Handel and Schimenti 2010. The FIRRM:FIGNL1 complex has recently been reported to interact with both RAD51 and DMC1 recombinases and limit the formation of meiotic crossovers by regulating RAD51 and DMC1 dynamics during meiosis (Fernandes et al. 2018)."
BMGC_PW1704,BMG_PW4571,,,"Phosphorylation of Shc at three tyrosine residues, 239, 240 (Gotoh et al. 1996) and 317 (Salcini et al. 1994) involves unidentified tyrosine kinases presumed to be part of the activated receptor complex. These phosphorylated tyrosines subsequently bind SH2 signaling proteins such as Grb2, Gab2 and SHIP that are involved in the regulation of different signaling pathways. Grb2 can associate with the guanosine diphosphate-guanosine triphosphate exchange factor Sos1, leading to Ras activation and regulation of cell proliferation. Downstream signals are mediated via the Raf-MEK-Erk pathway.Grb2 can also associate through Gab2 with PI3K and with SHIP. Figure reproduced from Gu, H. et al. 2000. Mol. Cell. Biol. 20(19):7109-7120 Copyright American Society for Microbiology. All Rights Reserved."
BMGC_PW1705,BMG_PW4572,,,"Cbl is an E3 ubiquitin-protein ligase that negatively regulates signaling pathways by targeting proteins for ubiquitination and proteasomal degradation (Rao et al. 2002). Cbl negatively regulates PI3K via this mechanism (Dufour et al. 2008). The binding of Cbl to the p85 subunit of PI3K is mediated at least in part by tyrosine phosphorylation at Y731 (Dufour et al. 2008). Fyn and the related kinases Hck and Lyn are known to be associated with Cbl (Anderson et al. 1997, Hunter et al. 1999). Fyn is proven capable of Cbl Y731 phosphorylation (Hunter et al. 1999).The association of Fyn and Cbl has been described as constitutive (Hunter et al. 1999). CBL further associates with the p85 subunit of PI3K (Hartley et al. 1995, Anderson et al. 1997, Hunter et al. 1997), this also described as constitutive and mediated by the SH3 domain of p85. Binding of the SH2 domain of p85 to a specific phosphorylation site in Cbl is postulated to explain the the increase in Cbl/p85 association seen in activated cells (Panchamoorthy et al 1996) which negatively regulates PI3K activity (Fang et al. 2001). The negative effect of increased Cbl-PI3K interaction is mediated by Y731 of Cbl. Cbl binding increases PI3K ubiquitination and proteasome degradation (Dufour et al. 2008). Cbl is constitutively associated with Grb in resting hematopoietic cells (Anderson et al. 1997, Odai et al. 1995, Park et al. 1998, Panchamoorthy et al. 1996). Both the SH2 and SH3 domains of Grb2 are involved. Cbl has 2 distinct C-terminal domains, proximal and distal. The proximal domain binds Grb2 in resting and stimulated cells, and in stimulated cells also binds Shc. The distal domain binds the adaptor protein CRKL. Tyrosine phosphorylation of Cbl in response to IL-3 releases the SH3 domain of Grb2 which then is free to bind other molecules (Park et al. 1998). Cbl is tyrosine phosphorylated in response to many cytokines including IL-3, IL-2 (Gesbert et al. 1998) and IL-4 (Ueno et al. 1998)."
BMGC_PW1706,BMG_PW4573,,,"There are several proteins and mechanisms involved in controlling the extent of ligand stimulation of IFNA/B signaling. These mechanisms can effect every step of the IFNA/B cascade. Dephosphorylation of JAK and STAT by SHP protein phosphatases, inhibition of STAT function in the nucleus by protein inhibitors of activated STATs (PIAS) proteins, inhibition of tyrosine kinase activity of JAKs by SOCS as well as inhibition of JAK and IFNAR2 interaction by UBP43 are few of the negative regulation mechanisms in controling type I IFN signaling."
BMGC_PW1707,BMG_PW4574,,,"Mucins are a family of high molecular weight, heavily glycosylated proteins (glycoconjugates) produced by epithelial tissues in most metazoa. Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. To date, there are approximately 20 genes that express mucins. Mature mucins are composed of two distinct regions: (1) The amino- and carboxy-terminal regions are very lightly glycosylated, but rich in cysteines. The cysteine residues participate in establishing disulfide linkages within and among mucin monomers. (2) A large central region rich in serine, threonine and proline residues called the variable number of tandem repeat (VNTR) region which can become heavily O-glycosylated with hundreds of O-GalNAc glycans. N-acetyl-galactosamine (GalNAc) is the first glycan to be attached, forming the simplest mucin O-glycan. After this, several different pathways are possible generating ""core"" structures. Four core structures are commonly formed, several others are possible but infrequent. O-linked glycans are often capped by the addition of a sialic acid residue, terminating the addition of any more O-glycans (Brockhausen et al, 2009; Tarp and Clausen, 2008)."
BMGC_PW1708,BMG_PW4576,,,"Many plasma membrane proteins are in a constant flux throughout the internal trafficking pathways of the cell. Some receptors are continuously internalized into recycling endosomes and returned to the cell surface. Others are sorted into intralumenal vesicles of morphologically distinctive endosomes that are known as multivesicular bodies (MVBs). These MVBs fuse with lysosomes, resulting in degradation of their cargo by lysosomal acidic hydrolases. Endosomes can be operationally defined as being either early or late, referring to the relative time it takes for endocytosed material to reach either stage. Ultrastructural studies indicate that early endosomes are predominantly tubulovesicular structures, which constitute a major sorting platform in the cell, whereas late endosomes show the characteristics of typical MVBs and are capable of fusing with lysosomes. A well characterized signal for shunting membrane proteins into the degradative MVB pathway is the ubiquitylation of these cargoes. At the center of a vast protein:protein and protein:lipid interaction network that underpins ubiquitin mediated sorting to the lysosome are the endosomal sorting complexes required for transport (ESCRTs), which are conserved throughout all major eukaryotic taxa."
BMGC_PW1709,BMG_PW4577,,,"Endocytosis of iron loaded transferrin/receptor complex leads, after acidification of the endosome, to the separation of iron and its diffusion out of the vesicle. The endosome is not fused with a lysosome but recycles its content back to the cell surface where soon transferrin dissociates from its receptor (Dautry-Varsat, 1986)."
BMGC_PW1710,BMG_PW4578,,,"MAVS via its TRAF-interaction motif (TIM) directly interacts with TRAF3 and recruits TRAF3 to the signaling complex. TRAF3 acts as a scaffold for the assembly of a signaling complex composed of IKK epsilon/TBK1, leading to the activation of transcription factors IRF3/IRF7."
BMGC_PW1711,BMG_PW4579,,,"TRAF6 is crucial for both DDX58 (RIG-I)- and IFIH1 (MDA5)-mediated antiviral responses. The absence of TRAF6 resulted in enhanced viral replication and a significant reduction in the production of type I IFNs and IL6 after infection with RNA virus. Activation of NF-kB and IRF7, but not that of IRF3, was significantly impaired during RIG-like helicases (RLHs) signaling in the absence of TRAF6. TRAF6-induced activation of IRF is likely to be specific for IRF7, while TRAF3 is thought to activate both IRF3 and IRF7. These results strongly suggest that the TRAF6- and TRAF3-dependent pathways are likely to bifurcate at mitochondrial antiviral-signaling protein MAVS (IPS-1), but to converge later at IRF7 in order to co-operatively induce sufficient production of type I IFNs during RLH signaling."
BMGC_PW1712,BMG_PW4580,,,"The TRAF6/TAK1 signal activates a canonical IKK complex, resulting in the activation of NF-kappaB as well as MAPK cascades leading to the activation of AP-1. Although TRAF6/TAK1 has been implicated in Tool like receptor (TLR) mediated cytokine production, the involvement of these molecules in the regulation of type I IFN induction mediated by RIG-I (DDX58)/MDA5 (IFIH1) pathway is largely unknown. According to the study done by Yoshida et al. the DDX58:MAVS pathway requires TRAF6 and MAP3K, MEKK1 to activate NF-kappaB and MAP Kinases for optimal induction of type I IFNs."
BMGC_PW1713,BMG_PW4581,,,"Fas-AssociatedDeathDomain (FADD) and receptor interacting protein 1 (RIP1) are death domain containing molecules that interact with the C-terminal portion of MAVS (IPS-1) and induce NF-kB through interaction and activation of initiator caspases (caspase-8 and -10). Caspases are usually involved in apoptosis and inflammation but they also exhibit nonapoptotic functions. These nonapoptotic caspase functions involve prodomain-mediated activation of NF-kB. Processed caspases (caspase-8/10) encoding the DED (death effector domain) strongly activate NF-kB. The exact mechanism by which caspases mediate NF-kB activation is unclear, but the prodomains of caspase-8/10 may act as a scaffolding and allow the recruitment of the IKK complex in association with other signaling molecules."
BMGC_PW1714,BMG_PW4582,,,"As with other cytokine systems, production of type I IFN is a transient process, and can be hazardous to the host if unregulated, resulting in chronic cellular toxicity or inflammatory and autoimmune diseases. RIG-I-mediated production of IFN can, in turn, increase the transcription of RIG-I itself, thus setting into motion an IFN amplification loop, which if left unchecked, could become deleterious to the host. This module mainly focuses on the endogenous negative regulation of the RIG-I-like receptor (RLR) family proteins RIG-I (DDX58) and MDA5 (IFIH1)."
BMGC_PW1715,BMG_PW4583,,,"The P-type ATPases (E1-E2 ATPases) are a large group of evolutionarily related ion pumps that are found in bacteria, archaea and eukaryotes. They are referred to as P-type ATPases because they catalyze auto-phosphorylation of a key conserved aspartate residue within the pump. They all appear to interconvert between at least two different conformations, E1 and E2. Most members of this transporter family pump a large variety of cations (Kuhlbrandt W, 2004)."
BMGC_PW1716,BMG_PW4584,,,"Cell stimulation with viral double-stranded (ds) RNA and bacterial lipopolysaccharide (LPS) activate Toll-like receptors 3 (TLR3) and TLR4, respectively, triggering the activation the activation of two IKK-related serine/threonine kinases, TANK-binding kinase 1 (TBK1) and IκB kinase ε (IKKε, IKBKE) which directly phosphorylate interferon regulatory factor 3 (IRF3) and IRF7 promoting their dimerization and translocation into the nucleus. Although both kinases show structural and functional similarities, it seems that TBK1 and IKBKE differ in their regulation of downstream signaling events of TLR3/TLR4. IRF3 activation and interferon β (IFNβ) production by poly(I:C), a synthetic analog of dsRNA, are decreased in TBK1-deficient mouse fibroblasts, whereas normal activation was observed in the IKBKE-deficient fibroblasts. However, in double-deficient mouse fibroblasts, the activation of IRF3 is completely abolished, suggesting a partially redundant functions of TBK1 and IKKε (IKBKE) (Hemmi H et al., 2004). The poly(I:C)-induced phosphorylation of TBK1 and IRF3 was abolished in TRIF (TICAM1)-knockout human keratinocyte HACAT cells (Bakshi S et al., 2017). TICAM1 is utilized as an adaptor protein by TLR3 and TLR4 (Yamamoto M et al., 2003). TLR3 recruits and activates PI3 kinase (PI3K), which activates the downstream kinase, Akt, leading to full phosphorylation and activation of IRF3 (Sarkar SN et al., 2004). When PI3K is not recruited to TLR3 or its activity is blocked, IRF3 is only partially phosphorylated and fails to bind the promoter of the target gene (Sarkar SN et al., 2004)."
BMGC_PW1717,BMG_PW4585,,,"The role of IRAK1 kinase activity in the activation of NF-kappa-B by IL-1/TLR is still uncertain. It has been shown that a kinase-dead IRAK1 mutants can still activate NF-kappa-B. Furthermore, stimulation of IRAK1-deficient I1A 293 cells with LMP1 (latent membrane protein 1- a known viral activator of NF-kappa-B) leads to TRAF6 polyubiquitination and IKKbeta activation [Song et al 2006]. On the other hand, IRAK1 enhances p65 Ser536 phosphorylation [Song et al 2006] and p65 binding to the promoter of NF-kappa-B dependent target genes [Liu G et al 2008]. IRAK1 has also been shown to be itself Lys63-polyubiquitinated (probably by Pellino proteins, which have E3 ligase activity). Mutation of the ubiquitination sites on IRAK1 prevented interaction with the NEMO subunit of IKK complex and subsequent IL-1/TLR-induced NF-kappa-B activation [Conze et al 2008]. These data suggest that kinase activity of IRAK1 is not essential for its ability to activate NF-kappa-B, while its Lys63-polyubuquitination allows IRAK1 to bind NEMO thus facilitating association of TRAF6 and TAK1 complex with IKK complex followed by induction of NF-kappa-B. Upon IL-1/TLR stimulation IRAK1 protein can undergo covalent modifications including phosphorylation [Kollewe et al 2004], ubiquitination [Conze DB et al 2008] and sumoylation [Huang et al 2004]. Depending upon the nature of its modification, IRAK1 may perform distinct functions including activation of IRF5/7 [Uematsu et al 2005, Schoenemeyer et al 2005], NF-kappa-B [Song et al 2006], and Stat1/3 [Huang et al 2004, Nguyen et al 2003]."
BMGC_PW1718,BMG_PW4586,,,"Receptor-interacting protein 1 (RIP1) mediates the activation of proinflammatory cytokines via intermediate induction of IKK complex in NFkB pathways [Ea et al. 2006]. Poly(I-C) treatment stimulated the recruitment of RIP1, TRAF6, and TAK1 to the TLR3 receptor complex in human embryonic kidney HEK293 transfected with FLAG-tagged TLR3 [Cusson-Hermance et al. 2005]. RIP1 was shown to be dispensable for TRIF-dependent activation of IRF3, which occurs in a TRIF/TBK1/IKKi-dependent manner [Cusson-Hermance et al. 2005, Sato et al. 2003]"
BMGC_PW1719,BMG_PW4587,,,"Although IRAK-1 was originally thought to be a key mediator of TRAF6 activation in the IL1R/TLR signaling (Dong W et al. 2006), recent studies showed that IRAK-2, but not IRAK-1, led to TRAF6 polyubiquitination (Keating SE et al 2007). IRAK-2 loss-of-function mutants, with mutated TRAF6-binding motifs, could no longer activate NF-kB and could no longer stimulate TRAF-6 ubiquitination (Keating SE et al 2007). Furthermore, the proxyvirus protein A52 - an inhibitor of all IL-1R/TLR pathways to NF-kB activation, was found to interact with both IRAK-2 and TRAF6, but not IRAK-1. Further work showed that A52 inhibits IRAK-2 functions, whereas association with TRAF6 results in A52-induced MAPK activation. The strong inhibition effect of A52 was also observed on the TLR3-NFkB axis and this observation led to the discovery that IRAK-2 is recruited to TLR3 to activate NF-kB (Keating SE et al 2007). Thus, A52 possibly inhibits MyD88-independent TLR3 pathways to NF-kB via targeting IRAK-2 as it does for other IL-1R/TLR pathways, although it remains unclear how IRAK-2 is involved in TLR3 signaling. IRAK-2 was shown to have two TRAF6 binding motifs that are responsible for initiating TRAF6 signaling transduction (Ye H et al 2002)."
BMGC_PW1720,BMG_PW4588,,,"TRIF (TICAM1) was shown to induce IRF3/7 and NF-kappa-B activation as well as apoptosis through distinct intracellular signaling pathways (Yamamoto M et al., 2003; Fitzgerald KA et al., 2003; Han KJ et al., 2004; Kaiser WJ & Offermann MK 2005). TRIF consists of an N-terminal domain (NTD) (1-153), an intermediate disordered proline-rich region, a TIR domain, and a C-terminal region (Mahita J & Sowdhamin R 2017). The disordered proline-rich region between NTD domain and the TIR domain of TICAM1 contains binding sites for TRAF (TNF receptor associated factor) family proteins, which, in turn, recruit protein kinases to promote activation of IRF3 and/or NF-kappa-B (Sato S et al., 2003; Fitzgerald KA et al., 2003). The C-terminal region of TICAM1 (TRIF) can recruit receptor-interacting serine/threonine-protein kinase 1 (RIPK1), and this event is followed by the activation of the IKK complex or the induction of programmed cell death (Han KJ et al., 2004; Kaiser WJ & Offermann MK 2005)."
BMGC_PW1721,BMG_PW4589,,,"In human, together with ubiquitin-conjugating E2-type enzymes UBC13 and UEV1A (also known as UBE2V1), TRAF6 catalyses Lys63-linked ubiquitination. It is believed that auto polyubiquitination and oligomerization of TRAF6 is followed by binding the ubiquitin receptors of TAB2 or TAB3 (TAK1 binding protein 2 and 3), which stimulates phosphorylation and activation of TGF beta-activated kinase 1(TAK1). TAK1 phosphorylates IKK alpha and IKK beta, which in turn phosphorylate NF-kB inhibitors - IkB and eventually results in IkB degradation and NF-kB translocation to the nucleus. Also TAK1 mediates JNK and p38 MAP kinases activation by phosphorylating MKK4/7 and MKK3/6 respectivly resulting in the activation of many transcription factors. The role of TRAF6 is somewhat controversial and probably cell type specific. TRAF6 autoubiquitination was found to be dispensable for TRAF6 function to activate TAK1 pathway. These findings are consistent with the new mechanism of TRAF6-mediated NF-kB activation that was suggested by Xia et al. (2009). TRAF6 generates unanchored Lys63-linked polyubiquitin chains that bind to the regulatory subunits of TAK1 (TAB2 or TAB3) and IKK(NEMO), leading to the activation of the kinases. Xia et al. (2009) demonstrated in vitro that unlike polyubiquitin chains covalently attached to TRAF6 or IRAK, TAB2 and NEMO-associated ubiquitin chains were found to be unanchored and susceptible to N-terminal ubiquitin cleavage. Only K63-linked polyubiquitin chains, but not monomeric ubiquitin, activated TAK1 in a dose-dependent manner. Optimal activation of the IKK complex was achieved using ubiquitin polymers containing both K48 and K63 linkages. Furthermore, the authors proposed that the TAK1 complexes might be brougt in close proximity by binding several TAB2/3 to a single polyubiquitin chain to facilitate TAK1 kinase trans-phosphorylation. Alternativly, the possibility that polyUb binding promotes allosteric activation of TAK1 complex should be considered (Walsh et al 2008)."
BMGC_PW1722,BMG_PW4590,,,"At least two mechanisms of transport of proteins from the ER to the Golgi have been described. One is a general flow requiring no export signals (Wieland et al, 1987; Martinez-Menarguez et al, 1999). The other is mediated by LMAN1/MCFD2, mannose-binding lectins that recognize a glycan signal (Zhang B et al, 2003)."
BMGC_PW1723,BMG_PW4920,,,"In plasmacytoid dendritic cell induction of type I IFNs critically depends on IFN regulatory factor 7 in TLR7 and 9 signaling (Honda et al 2005). IRF-7, but not IRF3, interacts with MyD88, TRAF6, and IRAKs and translocates to the nucleus upon phosphorylation (Kawai et al 2004; Uematsu et al 2005). TLR7/8 signaling was shown to induce IRF5 activation along with IRF7 [Schoenemeyer et al 2005], while IRF8 [Tsujimura H et al 2004] and IRF1 were reported to be implicated in TLR9 signaling."
BMGC_PW1724,BMG_PW4921,,,TRAF6 mediates NFkB activation via canonical phosphorylation of IKK complex by TAK1. TRAF6 and TAK1 also regulate MAPK cascades leading to the activation of AP-1.
BMGC_PW1725,BMG_PW4922,,,"The role of IRAK1 kinase activity in the activation of NF-kappa-B by IL-1/TLR is still uncertain. It has been shown that a kinase-dead IRAK1 mutants can still activate NF-kappa-B. Furthermore, stimulation of IRAK1-deficient I1A 293 cells with LMP1 (latent membrane protein 1- a known viral activator of NF-kappa-B) leads to TRAF6 polyubiquitination and IKKbeta activation [Song et al 2006]. On the other hand, IRAK1 enhances p65 Ser536 phosphorylation [Song et al 2006] and p65 binding to the promoter of NF-kappa-B dependent target genes [Liu G et al 2008]. IRAK1 has also been shown to be itself Lys63-polyubiquitinated (probably by Pellino proteins, which have E3 ligase activity). Mutation of the ubiquitination sites on IRAK1 prevented interaction with the NEMO subunit of IKK complex and subsequent IL-1/TLR-induced NF-kappa-B activation [Conze et al 2008]. These data suggest that kinase activity of IRAK1 is not essential for its ability to activate NF-kappa-B, while its Lys63-polyubuquitination allows IRAK1 to bind NEMO thus facilitating association of TRAF6 and TAK1 complex with IKK complex followed by induction of NF-kappa-B. Upon IL-1/TLR stimulation IRAK1 protein can undergo covalent modifications including phosphorylation [Kollewe et al 2004], ubiquitination [Conze DB et al 2008] and sumoylation [Huang et al 2004]. Depending upon the nature of its modification, IRAK1 may perform distinct functions including activation of IRF5/7 [Uematsu et al 2005, Schoenemeyer et al 2005], NF-kappa-B [Song et al 2006], and Stat1/3 [Huang et al 2004, Nguyen et al 2003]."
BMGC_PW1726,BMG_PW4923,,,"Upon binding of their ligands, TLR7/8 and TLR9 recruit a cytoplasmic adaptor MyD88 and IRAKs, downstream of which the signaling pathways are divided to induce either inflammatory cytokines or type I IFNs."
BMGC_PW1727,BMG_PW4924,,,"Although IRAK-1 was originally thought to be a key mediator of TRAF6 activation in the IL1R/TLR signaling (Dong W et al. 2006), recent studies showed that IRAK-2, but not IRAK-1, led to TRAF6 polyubiquitination (Keating SE et al 2007). IRAK-2 loss-of-function mutants, with mutated TRAF6-binding motifs, could no longer activate NF-kB and could no longer stimulate TRAF-6 ubiquitination (Keating SE et al 2007). Furthermore, the proxyvirus protein A52 - an inhibitor of all IL-1R/TLR pathways to NF-kB activation, was found to interact with both IRAK-2 and TRAF6, but not IRAK-1. Further work showed that A52 inhibits IRAK-2 functions, whereas association with TRAF6 results in A52-induced MAPK activation. The strong inhibition effect of A52 was also observed on the TLR3-NFkB axis and this observation led to the discovery that IRAK-2 is recruited to TLR3 to activate NF-kB (Keating SE et al 2007). Thus, A52 possibly inhibits MyD88-independent TLR3 pathways to NF-kB via targeting IRAK-2 as it does for other IL-1R/TLR pathways, although it remains unclear how IRAK-2 is involved in TLR3 signaling. IRAK-2 was shown to have two TRAF6 binding motifs that are responsible for initiating TRAF6 signaling transduction (Ye H et al 2002)."
BMGC_PW1728,BMG_PW4937,,,"In the latter compartments of the distal Golgi the N-Glycan is further modified, leading to the wide range of N-Glycans observed in multicellular organisms. The first step of N-Glycan elongation in the Golgi is the addition of a GlcNAc residue on the alpha 1,3 branch by the enzyme MGAT1 (GlcNAc-TI), which commits the elongation pathway to Complex or Hybrid N-Glycans from Oligomannose N-Glycans. At this point, the pathway bifurcates again to generate Complex or Hybrid N-Glycans. The addition of a GlcNAc in the middle of the two arms of the N-Glycan, catalyzed by MGAT3 (GNT-III), inhibits the removal of the mannoses on the alpha1,3 branches by MAN2 and the addition of a GlcNAc by MGAT2 (GlcNAc-TII), and commits the pathway toward the synthesis of hybrid N-Glycans. Alternatively, the removal of these mannoses and the action of MGAT2 leads to the synthesis of complex N-Glycans (Kornfeld and Kornfeld 1985). The exact structure of the network of reactions leading to Complex or Hybrid N-Glycans is still not completely described and validated experimentally. Here we will annotate only one generic reaction for each of the enzymes known to participate in this process. For a better annotation on the reactions and genes involved in the synthesis of Complex and Hybrid N-Glycans we recommend the GlycoGene Database (Ito H. et al, 2010) (http://riodb.ibase.aist.go.jp/rcmg/ggdb/textsearch.jsp) for annotations on genes, and the Consortium for Functional Genomics (http://riodb.ibase.aist.go.jp/rcmg/ggdb/textsearch.jsp) for annotation of Glycan structures and reactions. Moreover, a computationally inferred prediction on the structure of this network is available through the software GlycoVis (Hossler P. et. al. 2006)."
BMGC_PW1729,BMG_PW4938,,,"N-glycans are further modified after the commitment to Complex or Hybrid N-glycans. The exact structure of the network of metabolic reactions involved is complex and not yet validated experimentally. Here we will show a generic reaction for each of the genes known to be involved in N-Glycosylation. For a better annotation of the reactions and genes involved in the synthesis of Complex and Hybrid N-glycans we recommend the GlycoGene Database (Ito H. et al, 2010) (http://riodb.ibase.aist.go.jp/rcmg/ggdb/textsearch.jsp) for annotations of genes, and the Consortium for Functional Genomics (http://riodb.ibase.aist.go.jp/rcmg/ggdb/textsearch.jsp) for annotation of Glycan structures and reactions. Moreover, a computationally inferred prediction for the structure of this network is available through the software GlycoVis (Hossler P. et. al. 2006)."
BMGC_PW1730,BMG_PW4940,,,"If MAN2 acts before MGAT3, the pathway progresses to complex N-glycans, because MAN2 is not able to operate on bisected oligosaccharides (11421343, page 5). The expression of MAN2 over MGAT3 in a tissue can regulate the synthesis of hybrid or complex N-glycans."
BMGC_PW1731,BMG_PW4943,,,"Mammalian myeloid differentiation factor 88 (MyD88) is Toll/interleukin (IL)-1 (TIR)-domain containing adapter protein which plays crucial role in TLR signaling. All TLRs, with only one exception of TLR3, can initiate downstream signaling trough MyD88. In the MyD88 - dependent pathway, once the adaptor is bound to TLR it leads to recruitment of IL1 receptor associated kinase family IRAK which is followed by activation of tumour necrosis factor receptor-associated factor 6 (TRAF6) . TRAF6 is an ubiquitin E3 ligase which in turn induces TGF-beta activating kinase 1 (TAK1) auto phosphorylation. Once activated TAK1 can ultimately mediate the induction of the transcription factor NF-kB or the mitogen-activated protein kinases (MAPK), such as JNK, p38 and ERK. This results in the translocation of the activated NF-kB and MAPKs to the nucleus and the initiation of appropriate gene transcription leading to the production of many proinflammatory cytokines and antimicrobial peptides."
BMGC_PW1732,BMG_PW4953,,,"Nonsense-mediated decay has been observed with mRNAs that do not have an exon junction complex (EJC) downstream of the termination codon (reviewed in Isken and Maquat 2007, Chang et al. 2007, Behm-Ansmant et al. 2007, Rebbapragada and Lykke-Andersen 2009, Nicholson et al. 2010). In these cases the trigger is unknown but a correlation with the length of the 3' UTR has sometimes been seen. The current model posits a competition between PABP and UPF1 for access to eRF3 at the terminating ribosome (Ivanov et al. 2008, Singh et al. 2008, reviewed in Bhuvanagiri et al. 2010). Abnormally long 3' UTRs may prevent PABP from efficiently interacting with eRF3 and allow UPF1 to bind eRF3 instead. Long UTRs with hairpin loops may bring PABP closer to eRF3 and help evade NMD (Eberle et al. 2008). The pathway of degradation taken during EJC-independent NMD has not been elucidated. It is thought that phosphorylation of UPF1 by SMG1 and recruitment of SMG6 or SMG5 and SMG7 are involved, as with EJC-enhanced NMD, but this has not yet been shown."
BMGC_PW1733,BMG_PW4954,,,"During normal translation termination eRF3 associates with the ribosome and then interacts with PABP bound to the polyadenylate tail of the mRNA to release the ribosome and allow a new round of translation to commence. Nonsense-mediated decay (NMD) is triggered if eRF3 at the ribosome interacts with UPF1, which may compete with PABP (reviewed in Isken and Maquat 2007, Chang et al. 2007, Behm-Ansmant et al. 2007, Rebbapragada and Lykke-Andersen 2009, Bhuvanagiri et al. 2010, Nicholson et al. 2010, Durand and Lykke-Andersen 2011). An exon junction located 50-55 nt downstream of a termination codon is observed to enhance NMD. Exon-junction complexes (EJCs) are deposited on the mRNA during splicing in the nucleus, remain on mRNAs after transport to the cytosol, and are dislodged by the ribosome as it progresses along the mRNA during the pioneer round of translation (Gehring et al. 2009). EJCs contain the core factors eIF4A-III, Magoh-Y14, and CASC3 as well as the peripheral factors RNPS1, UPF2, and UPF3. UPF2 and UPF3 recruit UPF1 to eRF3 at the terminating ribosome. Thus an EJC downstream of a termination codon will not have been dislodged during translation and will recruit UPF1, triggering NMD. UPF1 is believed to form a complex containing SMG1, SMG8, and SMG9. In the key regulatory step of NMD SMG1 phosphorylates UPF1. The phosphorylated UPF1 then recruits either SMG6 or SMG5 and SMG7. SMG6 is itself an endoribonuclease that cleaves the mRNA. SMG5 and SMG7 do not have endoribonuclease activty, but are thought to recruit ribonucleases. Nonsense-mediated decay has been observed to involve deadenlyation, decapping, and both 5' to 3' and 3' to 5' exonuclease activities, but the exact degradative pathways taken by a given mRNA are not yet known. UPF1 also plays roles in Staufen-mediated decay, histone mRNA decay, telomere maintenance, genome integrity, and may play a role in normal termination of translation."
BMGC_PW1734,BMG_PW4969,,,O-glycan biosynthesis can be terminated (or modified) by the addition of sialic acid residues on Core 1 and 2 glycoproteins by sialyltransferases (Varki et al. 2009).
BMGC_PW1735,BMG_PW4970,,,"Amyloid is a term used to describe deposits of fibrillar proteins, typically extracellular. The abnormal accumulation of amyloid, amyloidosis, is a term associated with tissue damage caused by amyloid deposition, seen in numerous diseases including neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's. Amyloid deposits consist predominantly of amyloid fibrils, rigid, non-branching structures that form ordered assemblies, characteristically with a cross beta-sheet structure where the sheets run parallel to the direction of the fibril (Sawaya et al. 2007). Often the fibril has a left-handed twist (Nelson & Eisenberg 2006). At least 27 human proteins form amyloid fibrils (Sipe et al. 2010). Many of these proteins have non-pathological functions; the trigger that leads to abnormal aggregations differs between proteins and is not well understood but in many cases the peptides are abnormal fragments or mutant forms arising from polymorphisms, suggesting that the initial event may be aggregation of misfolded or unfolded peptides. Early studies of Amyloid-beta assembly led to a widely accepted model that assembly was a nucleation-dependent polymerization reaction (Teplow 1998) but it is now understood to be more complex, with multiple 'off-pathway' events leading to a variety of oligomeric structures in addition to fibrils (Roychaudhuri et al. 2008), though it is unclear whether these intermediate steps are required in vivo. An increasing body of evidence suggests that these oligomeric forms are primarily responsible for the neurotoxic effects of Amyloid-beta (Roychaudhuri et al. 2008), alpha-synuclein (Winner et al. 2011) and tau (Dance & Strobel 2009, Meraz-Rios et al. 2010). Amyloid oligomers are believed to have a common structural motif that is independent of the protein involved and not present in fibrils (Kayed et al. 2003). Conformation dependent, aggregation specific antibodies suggest that there are 3 general classes of amyloid oligomer structures (Glabe 2009) including annular structures which may be responsible for the widely reported membrane permeabilization effect of amyloid oligomers. Toxicity of amyloid oligomers preceeds the appearance of plaques in mouse models (Ferretti et al. 2011). Fibrils are often associated with other molecules, notably heparan sulfate proteoglycans and Serum Amyloid P-component, which are universally associated and seem to stabilize fibrils, possibly by protecting them from degradation."
BMGC_PW1736,BMG_PW4974,,,"L-Serine is needed in human brain in large amounts as precursor to important biomolecules such as nucleotides, phospholipids and the neurotransmitters glycine and D-serine. The pathway for its synthesis starts with 3-phosphoglycerate and it later needs glutamate as an amination agent. Deficiencies in the participating enzymes lead to severe neurological symptoms that are treatable with serine if treatment starts early (de Koning & Klomp 2004)."
BMGC_PW1737,BMG_PW4975,,,"Functional GABA B receptors are heteromers of GABA B1 and B2 subunits, complexed with G protein alpha-i, 0, beta, and gamma subunits. They function as metabotropic receptors. When GABA is bound to the B1 sub-unit, the B2 subunit undergoes a conformational change that releases the G alpha-i G0 dimer (which binds and inactivates cytosolic adenylate cyclase) and the G beta G gamma dimer (which activates the GIRK (KIR3) potassium channel) (Pinard et al. 2010)."
BMGC_PW1738,BMG_PW4976,,,"Two inherent features of complement activation make its regulation very important: 1. There is an inherent positive feedback loop because the product of C3 activation forms part of an enzyme that causes more C3 activation. 2. There is continuous low-level activation of the alternative pathway (see Spontaneous hydrolysis of C3 thioester). Complement cascade activation is regulated by a family of related proteins termed the regulators of complement activation (RCA). These are expressed on healthy host cells. Most pathogens do not express RCA proteins on their surface, but many have found ways to evade the complement system by stably binding the RCA that circulates in human plasma (Lambris et al. 2008); trapping RCA is by far the most widely employed strategy for avoiding the complement response. RCA recruitment is common in bacteria such as E. coli and streptococci (Kraiczy & Wurzner 2006) and has also been described for viruses, fungi and parasites. RCA deposition and the complement system also have an important role in tissue homeostasis, clearing dead cells and debris, and preventing damage from oxidative stress (Weismann et al. 2011). RCA proteins control complement activation in two different ways; by promoting the irreversible dissociation (decay acceleration) of complement convertases and by acting as cofactors for Complement factor I (CFI)-mediated cleavage of C3b and C4b. Decay accelerating factor (DAF, CD55), Complement factor H (FH), Membrane Cofactor Protein (MCP) and Complement receptor 1 (CR1) are composed of arrays of tandem globular domains termed CCPs (complement control protein repeats) or SCRs (short consensus repeats). CR1, MCP and FH are cofactors for the CFI-mediated cleavage of C3b, generating iC3b. CR1 and MCP are also cofactors for C4b cleavage. C4BP is an additional cofactor for the CFI-mediated cleavage of C4b."
BMGC_PW1739,BMG_PW5021,,,"Intracellular foreign or aberrant host proteins are cleaved into peptide fragments of a precise size, such that they can be loaded on to class I MHC molecules and presented externally to cytotoxic T cells. The ubiquitin-26S proteasome system plays a central role in the generation of these class I MHC antigens. Ubiquitination is the mechanism of adding ubiquitin to lysine residues on substrate protein leading to the formation of a polyubiquitinated substrate. This process involves three classes of enzyme, an E1 ubiquitin-activating enzyme, an E2 ubiquitin-conjugating enzyme, and an E3 ubiquitin ligase. Polyubiquitination through lysine-48 (K48) generally targets the substrate protein for proteasomal destruction. The protease responsible for the degradation of K48-polyubiquitinated proteins is the 26S proteasome. This proteasome is a two subunit protein complex composed of the 20S (catalytic core particle) and 19S (regulatory particle) proteasome complexes. The proteasome eliminates most of the foreign and non-functional proteins from the cell by degrading them into short peptides; only a small fraction of the peptides generated are of the correct length to be presented by the MHC class I system. It has been calculated that between 994 and 3122 protein molecules have to be degraded for the formation of a single, stable MHC class I complex at the cell surface, with an average efficiency of 1 in 2000 (Kloetzel et al. 2004, Princiotta et al. 2003)."
BMGC_PW1740,BMG_PW5022,,,"Unlike other glycoproteins, correct folding of MHC class I molecules is not sufficient to trigger their exit from the ER, they exit only after peptide loading. Described here is the process of antigen presentation which consists of the folding, assembly, and peptide loading of MHC class I molecules. The newly synthesized MHC class I Heavy Chain (HC) is initially folded with the help of several chaperones (calnexin, BiP, ERp57) and then binds with Beta-2-microglobulin (B2M). This MHC:B2M heterodimer enters the peptide loading complex (PLC), a multiprotein complex that includes calreticulin, endoplasmic reticulum resident protein 57 (ERp57), transporter associated with antigen processing (TAP) and tapasin. Peptides generated from Ub-proteolysis are transported into the ER through TAP. These peptides are further trimmed by ER-associated aminopeptidase (ERAP) and loaded on to MHC class I molecules. Stable MHC class I trimers with high-affinity peptide are transported from the ER to the cell surface by the Golgi apparatus."
BMGC_PW1741,BMG_PW5023,,,"Kinesins are a superfamily of microtubule-based motor proteins that have diverse functions in transport of vesicles, organelles and chromosomes, and regulate microtubule dynamics. There are 14 families of kinesins, all reprsented in humans. A standardized nomenclature was published in 2004 (Lawrence et al.)."
BMGC_PW1742,BMG_PW5025,,,"Megakaryocytes (MKs) give rise to circulating platelets (thrombocytes) through terminal differentiation of MKs which release cytoplasmic fragments as circulating platelets. As MKs mature they undergo endoreduplication (polyploidisation) and expansion of cytoplasmic mass to cell sizes larger than 50-100 microns, and ploidy ranges up to 128 N. As MKs mature, the polyploid nucleus becomes horseshoe-shaped, the cytoplasm expands, and platelet organelles and the demarcation membrane system are amplified. Proplatelet projections form which give rise to de novo circulating platelets (Deutsch & Tomer 2006). The processes of megakaryocytopoiesis and platelet production occur within a complex microenvironment where chemokines, cytokines and adhesive interactions play major roles (Avecilla et al. 2004). Megakaryocytopoiesis is regulated at several levels including proliferation, differentiation and platelet release (Kaushansky 2003). Thrombopoietin (TPO/c-Mpl ligand) is the most potent cytokine stimulating proliferation and maturation of MK progenitors (Kaushansky 2005) but many other growth factors are involved. MK development is controlled by the action of multiple transcription factors. Many MK-specific genes are co-regulated by GATA and friend of GATA (FOG), RUNX1 and ETS proteins. Nuclear factor erythroid 2 (NF-E2), which has an MK-erythroid specific 45-kDa subunit, controls terminal MK maturation, proplatelet formation and platelet release (Schulze & Shivdasani 2004). NF-E2 deficient mice have profound thrombocytopenia (Shiraga et al. 1999). MYB (c-myb) functions with EP300 (p300) as a negative regulator of thrombopoiesis (Metcalf et al. 2005). During MK maturation, internal membrane systems, granules and organelles are assembled. Cytoplasmic fragmentation requires changes in the MK cytoskeleton and formation of organelles and channels. Individual organelles migrate from the cell body to the proplatelet ends, with approximately 30 percent of organelles/granules in motion at any given time (Richardson et al. 2005)."
BMGC_PW1743,BMG_PW5034,,,"Mature B cells express IgM and IgD immunoglobulins which are complexed with Ig-alpha (CD79A, MB-1) and Ig-beta (CD79B, B29) to form the B cell receptor (BCR) (Fu et al. 1974, Fu et al. 1975, Kunkel et al. 1975, Van Noesal et al. 1992, Sanchez et al. 1993, reviewed in Brezski and Monroe 2008). Binding of antigen to the immunoglobulin activates phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) in the cytoplasmic tails of Ig-alpha and Ig-beta by Src family tyrosine kinases, including LYN, FYN, and BLK (Nel et al. 1984, Yamanashi et al. 1991, Flaswinkel and Reth 1994, Saouaf et al. 1994, Hata et al. 1994, Saouaf et al. 1995, reviewed in Gauld and Cambier 2004, reviewed in Harwood and Batista 2010). The protein kinase SYK may also be involved in phosphorylating the ITAMs. The protein kinase SYK binds the phosphorylated immunoreceptor tyrosine-activated motifs (ITAMs) on the cytoplasmic tails of Ig-alpha (CD79A, MB-1) and Ig-beta (CD79B, B29) (Wienands et al. 1995, Rowley et al. 1995, Tsang et al. 2008). The binding causes the activation and autophosphorylation of SYK (Law et al. 1994, Irish et al. 2006, Baldock et al. 2008, Tsang et al. 2008, reviewed in Bradshaw 2010). Activated SYK and other kinases phosphorylate BLNK (SLP-65, BASH) and BCAP. LYN and FYN phosphorylate CD19. Phosphorylated BLNK, BCAP, and CD19 serve as scaffolds which recruit effectors to the plasma membrane and assemble large complexes, the signalosomes. BCAP and CD19 recruit phosphoinositol 3-kinase (PI3K). BLNK recruits phospholipase C gamma (predominantly PLC-gamma2 in B cells, Coggeshall et al. 1992), NCK, BAM32, BTK, VAV1, and SHC. The effectors are phosphorylated by SYK and other kinases. Phosphorylated BCAP recruits PI3K, which is phosphorylated by a SYK-dependent mechanism (Kuwahara et al. 1996) and produces phosphatidylinositol-3,4,5-trisphosphate (PIP3). Phosphorylated CD19 likewise recruits PIP3K. PIP3 recruits BAM32 (Marshall et al. 2000) and BTK (de Weers et al. 1994, Baba et al. 2001) to the plasma membrane via their PH domains. PIP3 also recruits and activates PLC-gamma1 and PLC-gamma2 (Bae et al. 1998). BTK binds phosphorylated BLNK via its SH2 domain (Baba et al. 2001). BTK phosphorylates PLC-gamma2 (Rodriguez et al. 2001), which activates phospholipase activity (Carter et al. 1991, Roifman and Wang 1992, Kim et al. 2004, Sekiya et al. 2004). Phosphorylated BLNK recruits PLC-gamma, VAV, GRB2, and NCK (Fu and Chan 1997, Fu et al. 1998, Chiu et al. 2002). PLC-gamma hydrolyzes phosphatidylinositol-4,5-bisphosphate to yield inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (Carter et al. 1991, Kim et al. 2004). IP3 binds receptors on the endoplasmic reticulum and causes release of Ca2+ ions from the ER into the cytosol. The depletion of calcium from the ER in turn activates STIM1 to interact with ORAI and TRPC1 channels (and possibly other TRP channels) in the plasma membrane, resulting in an influx of extracellular calcium ions (Mori et al. 2002, Muik et al. 2008, Luik et al. 2008, Park et al. 2009)."
BMGC_PW1744,BMG_PW5036,,,"Ion channels mediate the flow of ions across the plasma membrane of cells. They are integral membrane proteins, typically a multimer of proteins, which, when arranged in the membrane, create a pore for the flow of ions. There are different types of ion channels. P-type ATPases undergo conformational changes to translocate ions. Ligand-gated ion channels operate like a gate, opened or closed by a chemical signal. Voltage-gated ion channels are activated by changes in electrical potential difference at the membrane (Purves, 2001; Kuhlbrandt, 2004)."
BMGC_PW1745,BMG_PW5101,,,GABA B receptors are metabotropic receptors that are functionally linked to C type G protein coupled receptors.? GABA B receptors are activated upon ligand binding. The GABA B1 subunit binds ligand and GABA B2 subunit modulates the activity of adenylate cyclase via the intracellular loop.? GABA B receptors show inhibitory activity via Galpha/G0 subunits via the inhibition of adenylate cyclase or via the activity of Gbeta/gamma subunits that mediate the inhibition of voltage gated Ca2+ channels.
BMGC_PW1746,BMG_PW5120,,,GABA B receptors are coupled to Gproteins and function by increasing the K+ and decreasing the Ca2+ inside the cell. The increase in K+ increases the negative membrane potential of the cell thereby hyper polarizing the cell which inhibits the release of neurotransmitters. The decrease in Ca2+ also inhibits neurotransmitter in two ways; first by preventing the fusion of synaptic vesicles containing the neurotransmitter with the plasma membrane and second by decreasing the Ca2+ dependent recruitment of synaptic vesicles to the plasma membrane. In particular GABA B receptors inhibit voltage gated Ca2+ channels via the activity of Gbeta/Ggamma subunits of G proteins.
BMGC_PW1747,BMG_PW5130,,"AMP-activated protein kinase (AMPK) is a serine threonine kinase that is highly conserved through evolution. AMPK system acts as a sensor of cellular energy status. It is activated by increases in the cellular AMP:ATP ratio caused by metabolic stresses that either interfere with ATP production (eg, deprivation for glucose or oxygen) or that accelerate ATP consumption (eg, muscle contraction). Several upstream kinases, including liver kinase B1 (LKB1), calcium/calmodulin kinase kinase-beta (CaMKK beta), and TGF-beta-activated kinase-1 (TAK-1), can activate AMPK by phosphorylating a threonine residue on its catalytic alpha-subunit. Once activated, AMPK leads to a concomitant inhibition of energy-consuming biosynthetic pathways, such as protein, fatty acid and glycogen synthesis, and activation of ATP-producing catabolic pathways, such as fatty acid oxidation and glycolysis.",
BMGC_PW1748,BMG_PW5191,,"The proteasome is a protein-destroying apparatus involved in many essential cellular functions, such as regulation of cell cycle, cell differentiation, signal transduction pathways, antigen processing for appropriate immune responses, stress signaling, inflammatory responses, and apoptosis. It is capable of degrading a variety of cellular proteins in a rapid and timely fashion and most substrate proteins are modified by ubiquitin before their degradation by the proteasome. The proteasome is a large protein complex consisting of a proteolytic core called the 20S particle and ancillary factors that regulate its activity in various ways. The most common form is the 26S proteasome containing one 20S core particle and two 19S regulatory particles that enable the proteasome to degrade ubiquitinated proteins by an ATP-dependent mechanism. Another form is the immunoproteasome containing two 11S regulatory particles, PA28 alpha and PA28 beta, which are induced by interferon gamma under the conditions of intensified immune response. Other regulatory particles include PA28 gamma and PA200. Although PA28 gamma also belongs to a family of activators of the 20S proteasome, it is localized within the nucleus and forms a homoheptamer. PA28 gamma has been implicated in the regulation of cell cycle progression and apoptosis. PA200 has been identified as a large nuclear protein that stimulates proteasomal hydrolysis of peptides.",
BMGC_PW1749,BMG_PW5303,,"Allograft rejection is the consequence of the recipient's alloimmune response to nonself antigens expressed by donor tissues. After transplantation of organ allografts, there are two pathways of antigen presentation. In the direct pathway, recipient T cells react to intact allogeneic MHC molecules expressed on the surface of donor cells. This pathway would activate host CD4 or CD8 T cells. In contrast, donor MHC molecules (and all other proteins) shed from the graft can be taken up by host APCs and presented to recipient T cells in the context of self-MHC molecules - the indirect pathway. Such presentation activates predominantly CD4 T cells. A direct cytotoxic T-cell attack on graft cells can be made only by T cells that recognize the graft MHC molecules directly. Nontheless, T cells with indirect allospecificity can contribute to graft rejection by activating macrophages, which cause tissue injury and fibrosis, and are also likely to be important in the development of an alloantibody response to graft.",
BMGC_PW1750,BMG_PW5348,,"Gastric acid is a key factor in normal upper gastrointestinal functions, including protein digestion and calcium and iron absorption, as well as providing some protection against bacterial infections. The principal stimulants of acid secretion at the level of the parietal cell are histamine (paracrine), gastrin (hormonal), and acetycholine (ACh; neurocrine). Stimulation of acid secretion typically involves an initial elevation of intracellular calcium and cAMP, followed by activation of protein kinase cascades, which trigger the translocation of the proton pump, H+,K+-ATPase, from cytoplasmic tubulovesicles to the apical plasma membrane and thereby H+ secretion into the stomach lumen.",
BMGC_PW1751,BMG_PW5506,,"Oxytocin (OT) is a nonapeptide synthesized by the magno-cellular neurons located in the supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus. It exerts a wide variety of central and peripheral effects. However, its best-known and most well-established roles are stimulation of uterine contractions during parturition and milk release during lactation. Oxytocin also influences cardiovascular regulation and various social behaviors. The actions of OT are all mediated by one type of OT receptor (OTR). This is a transmembrane receptor belonging to the G-protein-coupled receptor superfamily. The main signaling pathway is the Gq/PLC/Ins3 pathway, but the MAPK and the RhoA/Rho kinase pathways are also activated, contributing to increased prostaglandin production and direct contractile effect on myometrial cells. In the cardiovascular system, OTR is associated with the ANP-cGMP and NO-cGMP pathways, which reduce the force and rate of contraction and increase vasodilatation.",
BMGC_PW1752,BMG_PW5768,,"Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that are activated by fatty acids and their derivatives. PPAR has three subtypes (PPARalpha, beta/delta, and gamma) showing different expression patterns in vertebrates. Each of them is encoded in a separate gene and binds fatty acids and eicosanoids. PPARalpha plays a role in the clearance of circulating or cellular lipids via the regulation of gene expression involved in lipid metabolism in liver and skeletal muscle. PPARbeta/delta is involved in lipid oxidation and cell proliferation. PPARgamma promotes adipocyte differentiation to enhance blood glucose uptake.",
BMGC_PW1753,BMG_PW6305,,,
BMGC_PW1754,BMG_PW6583,,,
BMGC_PW1755,BMG_PW6601,,"Estrogens are steroid hormones that regulate a plethora of physiological processes in mammals, including reproduction, cardiovascular protection, bone integrity, cellular homeostasis, and behavior. Estrogen mediates its cellular actions through two signaling pathways classified as ""nuclear-initiated steroid signaling"" and ""membrane-initiated steroid signaling"". In the ""nuclear"" pathway, estrogen binds either ERalpha or ERbeta, which in turn translocates to the nucleus, binds DNA at ERE elements and activates the expression of ERE-dependent genes. In ""membrane"" pathway, Estrogen can exert its actions through a subpopulation of ER at the plasma membrane (mER) or novel G-protein coupled E2 receptors (GPER). Upon activation of these receptors various signaling pathways (i.e. Ca2+, cAMP, protein kinase cascades) are rapidly activated and ultimately influence downstream transcription factors.",
BMGC_PW1756,BMG_PW6610,,,
BMGC_PW1757,BMG_PW6611,,,
BMGC_PW1758,BMG_PW6612,,,
BMGC_PW1759,BMG_PW6613,,,
BMGC_PW1760,BMG_PW6614,,"Serine is derived from 3-phospho-D-glycerate, an intermediate of glycolysis [MD:M00020], and glycine is derived from serine. Threonine is an essential amino acid, which animals cannot synthesize. In bacteria and plants, threonine is derived from aspartate [MD:M00018].",
BMGC_PW1761,BMG_PW6615,,"Cysteine and methionine are sulfur-containing amino acids. Cysteine is synthesized from serine through different pathways in different organism groups. In bacteria and plants, cysteine is converted from serine (via acetylserine) by transfer of hydrogen sulfide [MD:M00021]. In animals, methionine-derived homocysteine is used as sulfur source and its condensation product with serine (cystathionine) is converted to cysteine [MD:M00338]. Cysteine is metabolized to pyruvate in multiple routes. Methionine is an essential amino acid, which animals cannot synthesize. In bacteria and plants, methionine is synthesized from aspartate [MD:M00017]. S-Adenosylmethionine (SAM), synthesized from methionine and ATP, is a methyl group donor in many important transfer reactions including DNA methylation for regulation of gene expression. SAM may also be used to regenerate methionine in the methionine salvage pathway [MD:M00034].",
BMGC_PW1762,BMG_PW6616,,,
BMGC_PW1763,BMG_PW6617,,,
BMGC_PW1764,BMG_PW6618,,,
BMGC_PW1765,BMG_PW6619,,"Natural products containing carbon-phosphorous bonds, so-called C-P compounds, are derivatives of phosphonate and phosphinate with substitution of alkyl group for hydrogen of phosphorus-hydrogen bonds. C-P compounds have been found in many organisms, but only protists and bacteria, mostly Actinobacteria, have biosynthetic capacity. A common reaction in the biosynthetic pathway is C-P bond forming reaction from phosphoenolpyruvate (PEP) to phosphonopyruvate (PnPy) catalyzed by PEP phosphomutase. 2-Aminoethylphosphonate (AEP) is the most abundant C-P compound in the natural world. AEP derivatives include phosphonoprotein, phosphonoglycan, and phosphonolipid. Other known C-P compounds are bioactive substances used in medicine (antibiotics) and agriculture (herbicide) such as fosfomycin, FR-33289, rhizocticin, and bialaphos.",
BMGC_PW1766,BMG_PW6620,,,
BMGC_PW1767,BMG_PW6621,,,
BMGC_PW1768,BMG_PW6622,,,
BMGC_PW1769,BMG_PW6623,,"O-linked glycosylation is the attachment of monosaccharides to the hydroxyl groups of amino acids, mostly serine and threonine, and is found in eukaryotes, archaea and bacteria. O-glycans exhibit diverse types of modifications where the innermost monosaccharide is N-acetylgalactosamine (map00512), mannose in mammals (map00515), and others (this map) including N-acetylglucosamine, fucose, glucose, galactose, mannose in yeast and arabinose in plants.",
BMGC_PW1770,BMG_PW6624,,"Biosynthesis of mammalian O-mannosyl glycans is initiated by the transfer of mannose from mannose-P-Dol to serine or threonine residue, followed by extensions with N-acetylglucosamine (GlcNAc) and galactose (Gal) to generate core M1, M2 and M3 glycans. Core M1 and M2 glycans can then be further attached by fucose residues, sialic acid terminals and sulfatded glucuroinc acid terminals. Core M3 glycan is involved in the synthesis of alpha-dystroglycan, a heavily glycosylated protein found in muscle and brain tissues. Core M3 glycan contains a tandem repeat of ribitol 5-phosphate (Rbo5P) and -alpha3-GlcA-beta3-Xyl- repeating structures. Defects of genes encoding core glycans and modified core M3 glycans are associated with various congenital diseases, such as muscular dystrophies caused by reduced O-mannosylation of alpha-dystroglycan in skeletal muscles [DS:H00120].",
BMGC_PW1771,BMG_PW6625,,,
BMGC_PW1772,BMG_PW6626,,,
BMGC_PW1773,BMG_PW6627,,,
BMGC_PW1774,BMG_PW6628,,,
BMGC_PW1775,BMG_PW6629,,"Sulfur is an essential element for life and the metabolism of organic sulfur compounds plays an important role in the global sulfur cycle. Sulfur occurs in various oxidation states ranging from +6 in sulfate to -2 in sulfide (H2S). Sulfate reduction can occur in both an energy consuming assimilatory pathway and an energy producing dissimilatory pathway. The assimilatory pathway, which is found in a wide range of organisms, produces reduced sulfur compounds for the biosynthesis of S-containing amino acids and does not lead to direct excretion of sulfide. In the dissimilatory pathway, which is restricted to obligatory anaerobic bacterial and archaeal lineages, sulfate (or sulfur) is the terminal electron acceptor of the respiratory chain producing large quantities of inorganic sulfide. Both pathways start from the activation of sulfate by reaction with ATP to form adenylyl sulfate (APS). In the assimilatory pathway [MD:M00176] APS is converted to 3'-phosphoadenylyl sulfate (PAPS) and then reduced to sulfite, and sulfite is further reduced to sulfide by the assimilatory sulfite reductase. In the dissimilatory pathway [MD:M00596] APS is directly reduced to sulfite, and sulfite is further reduced to sulfide by the dissimilatory sulfite reductase. The capacity for oxidation of sulfur is quite widespread among bacteria and archaea, comprising phototrophs and chemolithoautotrophs. The SOX (sulfur-oxidation) system [MD:M00595] is a well-known sulfur oxidation pathway and is found in both photosynthetic and non-photosynthetic sulfur-oxidizing bacteria. Green sulfur bacteria and purple sulfur bacteria carry out anoxygenic photosynthesis with reduced sulfur compounds such as sulfide and elemental sulfur, as well as thiosulfate (in some species with the SOX system), as the electron donor for photoautotrophic growth. In some chemolithoautotrophic sulfur oxidizers (such as Thiobacillus denitrificans), it has been suggested that dissimilatory sulfur reduction enzymes operate in the reverse direction, forming a sulfur oxidation pathway from sulfite to APS and then to sulfate.",
BMGC_PW1776,BMG_PW6630,,,
BMGC_PW1777,BMG_PW6631,,,
BMGC_PW1778,BMG_PW6632,,,
BMGC_PW1779,BMG_PW6633,,"2-Oxocarboxylic acids, also called 2-oxo acids and alpha-keto acids, are the most elementary set of metabolites that includes pyruvate (2-oxopropanoate), 2-oxobutanoate, oxaloacetate (2-oxosuccinate) and 2-oxoglutarate. This diagram illustrates the architecture of chain extension and modification reaction modules for 2-oxocarboxylic acids. The chain extension module RM001 is a tricarboxylic pathway where acetyl-CoA derived carbon is used to extend the chain length by one. The chain modification modules RM002 (including RM032) and RM033, together with a reductive amination step (RC00006 or RC00036), generate basic and branched-chain amino acids, respectively. The modification module RM030 is used in the biosynthesis of glucosinolates, a class of plant secondary metabolites, for conversion to oxime followed by addition of thio-glucose moiety. Furthermore, the chain extension from 2-oxoadipate to 2-oxosuberate is followed by coenzyme B biosynthesis in methonogenic archaea.",
BMGC_PW1780,BMG_PW6634,,"This map presents a modular architecture of the biosynthesis pathways of twenty amino acids, which may be viewed as consisting of the core part and its extensions. The core part is the KEGG module for conversion of three-carbon compounds from glyceraldehyde-3P to pyruvate [MD:M00002], together with the pathways around serine and glycine. This KEGG module is the most conserved one in the KEGG MODULE database and is found in almost all the completely sequenced genomes. The extensions are the pathways containing the reaction modules RM001, RM033, RM032, and RM002 for biosynthesis of branched-chain amino acids (left) and basic amino acids (bottom), and the pathways for biosynthesis of histidine and aromatic amino acids (top right). It is interesting to note that the so-called essential amino acids that cannot be synthesized in human and other organisms generally appear in these extensions. Furthermore, the bottom extension of basic amino acids appears to be most divergent containing multiple pathways for lysine biosynthesis and multiple gene sets for arginine biosynthesis.",
BMGC_PW1781,BMG_PW6635,,,
BMGC_PW1782,BMG_PW6636,,,
BMGC_PW1783,BMG_PW6637,,,
BMGC_PW1784,BMG_PW6638,,"Sulfur is one of the six most common chemical elements CHNOPS that constitute living organisms. This map shows a biogeochemical cycle of sulfur compounds and how different microorganisms are responsible for chemical transformations under different environments including atmospheric, hydrospheric and lithospheric environments. Details of chemical reactions and responsible enzymes are shown in map00920 for Sulfur metabolism. Here chemical transformations are represented by KEGG modules, including sulfur reduction [MD:M00986] [KO:K16952] from elemental sulfur to hydrogen sulfide by sulfur-reducing bacteria and archaea, sulfide oxidation [MD:M00985] from hydrogen sulfide to elemental sulfur by sulfur-oxidizing phototrophs, sulfur oxidataion [MD:M00595 M00984] from thiosulfate to sulfate by sulfur-oxidizing chemotrophs, dissimilatory sulfate reduction [MD:M00596] by sulfate-reducing bacteria and archaea, and assimilatory sulfate reduction [MD:M00176 M00987] by both prokaryotes and eukaryotes excluding animals.",
BMGC_PW1785,BMG_PW6639,,"EGFR is a tyrosine kinase that participates in the regulation of cellular homeostasis. EGFR also serves as a stimulus for cancer growth. EGFR gene mutations and protein overexpression, both of which activate down- stream pathways, are associated with cancers, especially lung cancer. Several tyrosine kinase inhibitor (TKI) therapies against EGFR are currently administered and are initially effective in cancer patients who have EGFR mutations or aberrant activation of EGFR. However, the development of TKI resistance is common and results in the recurrence of tumors. Studies over the last decade have identified mechanisms that drive resistance to EGFR TKI treatment. Most outstanding mechanisms are: the secondary EGFR mutation (T790M), activation of alternative pathways (c-Met, HGF, AXL), aberrance of the downstream pathways (K-RAS mutations, loss of PTEN), impairment of the EGFR-TKIs-mediated apoptosis pathway (BCL2-like 11/BIM deletion polymorphism), histologic transformation, etc.",
BMGC_PW1786,BMG_PW6640,,"Endocrine therapy is a key treatment strategy to control or eradicate hormone-responsive breast cancer. The most commonly used endocrine therapy agents are selective estrogen receptor modulators (SERMs, e.g. tamoxifen), estrogen synthesis inhibitors (e.g. aromatase inhibitors (AIs) such as anastrozole, letrozole, and exemestane), and selective estrogen receptor down-regulators (SERDs, e.g. fulvestrant). However, resistance to these agents has become a major clinical obstacle. Mechanisms of endocrine resistance include loss of ER-alpha expression, altered expression of coactivators or coregulators that play a critical role in ER-mediated gene transcription, ligand-independent growth factor signaling cascades that activate kinases and ER-phosphorylation, altered availability of active tamoxifen metabolites regulated by drug-metabolizing enzymes, such as CYP2D6, and deregulation of the cell cycle and apoptotic machinery.",
BMGC_PW1787,BMG_PW6641,,"Since the 1940s, antifolates have played a pivotal role in drug treatment of malignant, microbial, parasitic and chronic inflammatory diseases. The molecular basis of the anti-proliferative activity of antifolates relies on inhibition of key enzymes in folate metabolism, which results in disruption of purine and thymidylate biosynthesis, inhibition of DNA replication and cell death. The anti-inflammatory properties of antifolate have been most strongly related to its ability to block the release of pro-inflammatory cytokines such as tumour necrosis factor (TNF)-alpha or interleukin (IL)-1beta. Cells may develop resistance to an antifolate drug by virtue of impaired drug transport into cells, augmented drug export, impaired activation of antifolates through polyglutamylation, augmented hydrolysis of antifolate polyglutamates, increased expression and mutation of target enzymes, and the augmentation of cellular tetrahydrofolate-cofactor pools in cells.",
BMGC_PW1788,BMG_PW6642,,"Platinum-based drugs cisplatin, carboplatin and oxaliplatin are widely used in the therapy of solid malignancies, including testicular, ovarian, head and neck, colorectal, bladder and lung cancers. The mechanism of action of Platinum-based drugs involves covalent binding to purine DNA bases, which primarily leads to cellular apoptosis. Their clinical success is, however, limited due to severe side effects and intrinsic or acquired resistance to the treatment. Platinum resistance could arise from decreased drug influx, increased drug efflux, intracellular detoxification by glutathione, etc., decreased binding (e.g., due to high intracellular pH), increased DNA repair, decreased mismatch repair, defective apoptosis, and altered oncogene expression.",
BMGC_PW1789,BMG_PW6643,,,
BMGC_PW1790,BMG_PW6644,,"The mRNA surveillance pathway is a quality control mechanism that detects and degrades abnormal mRNAs. These pathways include nonsense-mediated mRNA decay (NMD), nonstop mRNA decay (NSD), and no-go decay (NGD). NMD is a mechanism that eliminates mRNAs containing premature translation-termination codons (PTCs). In vertebrates, PTCs trigger efficient NMD when located upstream of an exon junction complex (EJC). Upf3, together with Upf1 and Upf2, may signal the presence of the PTC to the 5'end of the transcript, resulting in decapping and rapid exonucleolytic digestion of the mRNA. In the NSD pathway, which targets mRNAs lacking termination codons, the ribosome is believed to translate through the 3' untranslated region and stall at the end of the poly(A) tail. NSD involves an eRF3-like protein, Ski7p, which is hypothesized to bind the empty A site of the ribosome and recruit the exosome to degrade the mRNA from the 3' end. NGD targets mRNAs with stalls in translation elongation for endonucleolytic cleavage in a process involving the Dom34 and Hbs1 proteins.",
BMGC_PW1791,BMG_PW6645,,,
BMGC_PW1792,BMG_PW6646,,,
BMGC_PW1793,BMG_PW6647,,"After transcription, eukaryotic mRNA precursors contain protein-coding exons and noncoding introns. In the following splicing, introns are excised and exons are joined by a macromolecular complex, the spliceosome. The standard spliceosome is made up of five small nuclear ribonucleoproteins (snRNPs), U1, U2, U4, U5, and U6 snRNPs, and several spliceosome-associated proteins (SAPs). Spliceosomes are not a simple stable complex, but a dynamic family of particles that assemble on the mRNA precursor and help fold it into a conformation that allows transesterification to proceed. Various spliceosome forms (e.g. A-, B- and C-complexes) have been identified.",
BMGC_PW1794,BMG_PW6648,,"The protein export is the active transport of proteins from the cytoplasm to the exterior of the cell, or to the periplasmic compartment in Gram-negative bacteria. The sec dependent pathway is the general protein export system that transports newly synthesized proteins into or across the cell membrane. The translocation channel is formed from a conserved trimeric membrane protein complex, called the Sec61/SecY complex. The twin-arginine translocation (Tat) pathway is another protein transport system that transports folded proteins in bacteria, archaea, and chloroplasts. Many Tat systems comprise three functionally different membrane proteins, TatA, TatB, and TatC, but TatA and TatE seem to have overlapping functions, with TatA having by far the more important role.",
BMGC_PW1795,BMG_PW6651,,,
BMGC_PW1796,BMG_PW6652,,,
BMGC_PW1797,BMG_PW6653,,,
BMGC_PW1798,BMG_PW6658,,,
BMGC_PW1799,BMG_PW6660,,"The Ras proteins are GTPases that function as molecular switches for signaling pathways regulating cell proliferation, survival, growth, migration, differentiation or cytoskeletal dynamism. Ras proteins transduce signals from extracellular growth factors by cycling between inactive GDP-bound and active GTP-bound states. The exchange of GTP for GDP on RAS is regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Activated RAS (RAS-GTP) regulates multiple cellular functions through effectors including Raf, phosphatidylinositol 3-kinase (PI3K) and Ral guanine nucleotide-dissociation stimulator (RALGDS).",
BMGC_PW1800,BMG_PW6661,,"Ca2+ that enters the cell from the outside is a principal source of signal Ca2+. Entry of Ca2+ is driven by the presence of a large electrochemical gradient across the plasma membrane. Cells use this external source of signal Ca2+ by activating various entry channels with widely different properties. The voltage-operated channels (VOCs) are found in excitable cells and generate the rapid Ca2+ fluxes that control fast cellular processes. There are many other Ca2+-entry channels, such as the receptor-operated channels (ROCs), for example the NMDA (N-methyl-D-aspartate) receptors (NMDARs) that respond to glutamate. There also are second-messenger-operated channels (SMOCs) and store-operated channels (SOCs).             The other principal source of Ca2+ for signalling is the internal stores that are located primarily in the endoplasmic/sarcoplasmic reticulum (ER/SR), in which inositol-1,4,5-trisphosphate receptors (IP3Rs) or ryanodine receptors (RYRs) regulate the release of Ca2+. The principal activator of these channels is Ca2+ itself and this process of Ca2+-induced Ca2+ release is central to the mechanism of Ca2+ signalling. Various second messengers or modulators also control the release of Ca2+. IP3, which is generated by pathways using different isoforms of phospholipase C (PLCbeta, delta, epsilon, gamma and zeta), regulates the IP3Rs. Cyclic ADP-ribose (cADPR) releases Ca2+ via RYRs. Nicotinic acid adenine dinucleotide phosphate (NAADP) may activate a distinct Ca2+ release mechanism on separate acidic Ca2+ stores. Ca2+ release via the NAADP-sensitive mechanism may also feedback onto either RYRs or IP3Rs. cADPR and NAADP are generated by CD38. This enzyme might be sensitive to the cellular metabolism, as ATP and NADH inhibit it.             The influx of Ca2+ from the environment or release from internal stores causes a very rapid and dramatic increase in cytoplasmic calcium concentration, which has been widely exploited for signal transduction. Some proteins, such as troponin C (TnC) involved in muscle contraction, directly bind to and sense Ca2+. However, in other cases Ca2+ is sensed through intermediate calcium sensors such as calmodulin (CALM).",
BMGC_PW1801,BMG_PW6662,,"Cyclic GMP (cGMP) is the intracellular second messenger that mediates the action of nitric oxide (NO) and natriuretic peptides (NPs), regulating a broad array of physiologic processes. The elevated intracellular cGMP level exerts its physiological action through two forms of cGMP-dependent protein kinase (PKG), cGMP-regulated phosphodiesterases (PDE2, PDE3) and cGMP-gated cation channels, among which PKGs might be the primary mediator. PKG1 isoform-specific activation of established substrates leads to reduction of cytosolic calcium concentration and/or decrease in the sensitivity of myofilaments to Ca2+ (Ca2+-desensitization), resulting in smooth muscle relaxation. In cardiac myocyte, PKG directly phosphorylates a member of the transient potential receptor canonical channel family, TRPC6, suppressing this nonselective ion channel's Ca2+ conductance, G-alpha-q agonist-induced NFAT activation, and myocyte hypertrophic responses. PKG also opens mitochondrial ATP-sensitive K+ (mitoKATP) channels and subsequent release of ROS triggers cardioprotection.",
BMGC_PW1802,BMG_PW6663,,"cAMP is one of the most common and universal second messengers, and its formation is promoted by adenylyl cyclase (AC) activation after ligation of G protein-coupled receptors (GPCRs) by ligands including hormones, neurotransmitters, and other signaling molecules. cAMP regulates pivotal physiologic processes including metabolism, secretion, calcium homeostasis, muscle contraction, cell fate, and gene transcription. cAMP acts directly on three main targets: protein kinase A (PKA), the exchange protein activated by cAMP (Epac), and cyclic nucleotide-gated ion channels (CNGCs). PKA modulates, via phosphorylation, a number of cellular substrates, including transcription factors, ion channels, transporters, exchangers, intracellular Ca2+ -handling proteins, and the contractile machinery. Epac proteins function as guanine nucleotide exchange factors (GEFs) for both Rap1 and Rap2. Various effector proteins, including adaptor proteins implicated in modulation of the actin cytoskeleton, regulators of G proteins of the Rho family, and phospholipases, relay signaling downstream from Rap.",
BMGC_PW1803,BMG_PW6664,,"Viruses have evolved diverse mechanisms to evade detection and destruction by the immune system, including copying and repurposing host cytokine and cytokine receptor genes. Viral cytokines and cytokine receptors, together with a group of structurally unique, soluble, cytokine-binding or cytokine receptor-binding proteins, represent the three major molecular strategies for subversion and modulation of the host cytokine networks mainly in large DNA viruses. Viral cytokines and cytokine receptor homologs, including other binding proteins, may activate or inhibit cytokine signaling and possibly affect different aspects of immunity.",
BMGC_PW1804,BMG_PW6665,,"Nuclear factor-kappa B (NF-kappa B) is the generic name of a family of transcription factors that function as dimers and regulate genes involved in immunity, inflammation and cell survival. There are several pathways leading to NF-kappa B-activation. The canonical pathway is induced by tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) or byproducts of bacterial and viral infections. This pathway relies on IKK- mediated IkappaB-alpha phosphorylation on Ser32 and 36, leading to its degradation, which allows the p50/p65 NF-kappa B dimer to enter the nucleus and activate gene transcription. Atypical pathways are IKK-independent and rely on phosphorylation of IkappaB-alpha on Tyr42 or on Ser residues in IkappaB-alpha PEST domain. The non-canonical pathway is triggered by particular members of the TNFR superfamily, such as lymphotoxin-beta (LT-beta) or BAFF. It involves NIK and IKK-alpha-mediated p100 phosphorylation and processing to p52, resulting in nuclear translocation of p52/RelB heterodimers.",
BMGC_PW1805,BMG_PW6666,,"Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that functions as a master regulator of oxygen homeostasis. It consists of two subunits: an inducibly-expressed HIF-1alpha subunit and a constitutively-expressed HIF-1beta subunit. Under normoxia, HIF-1 alpha undergoes hydroxylation at specific prolyl residues which leads to an immediate ubiquitination and subsequent proteasomal degradation of the subunit. In contrast, under hypoxia, HIF-1 alpha subunit becomes stable and interacts with coactivators such as p300/CBP to modulate its transcriptional activity. Eventually, HIF-1 acts as a master regulator of numerous hypoxia-inducible genes under hypoxic conditions. The target genes of HIF-1 encode proteins that increase O2 delivery and mediate adaptive responses to O2 deprivation. Despite its name, HIF-1 is induced not only in response to reduced oxygen availability but also by other stimulants, such as nitric oxide, or various growth factors.",
BMGC_PW1806,BMG_PW6667,,"The forkhead box O (FOXO) family of transcription factors regulates the expression of genes in cellular physiological events including apoptosis, cell-cycle control, glucose metabolism, oxidative stress resistance, and longevity. A central regulatory mechanism of FOXO proteins is phosphorylation by the serine-threonine kinase Akt/protein kinase B (Akt/PKB), downstream of phosphatidylinositol 3-kinase (PI3K), in response to insulin or several growth factors. Phosphorylation at three conserved residues results in the export of FOXO proteins from the nucleus to the cytoplasm, thereby decreasing expression of FOXO target genes. In contrast, the stress-activated c-Jun N-terminal kinase (JNK) and the energy sensing AMP-activated protein kinase (AMPK), upon oxidative and nutrient stress stimuli phosphorylate and activate FoxOs. Aside from PKB, JNK and AMPK, FOXOs are regulated by multiple players through several post-translational modifications, including phosphorylation, but also acetylation, methylation and ubiquitylation.",
BMGC_PW1807,BMG_PW6668,,"Sphingomyelin (SM) and its metabolic products are now known to have second messenger functions in a variety of cellular signaling pathways. Particularly, the sphingolipid metabolites, ceramide (Cer) and sphingosine-1-phosphate (S1P), have emerged as a new class of potent bioactive molecules. Ceramide can be generated de novo or by hydrolysis of membrane sphingomyelin by sphingomyelinase (SMase). Ceramide is subsequently metabolized by ceramidase to generate sphingosine (Sph) which in turn produces S1P through phosphorylation by sphingosine kinases 1 and 2 (SphK1, 2). Both ceramide and S1P regulate cellular responses to stress, with generally opposing effects. S1P functions as a growth and survival factor, acting as a ligand for a family of G protein-coupled receptors, whereas ceramide activates intrinsic and extrinsic apoptotic pathways through receptor-independent mechanisms.",
BMGC_PW1808,BMG_PW6669,,"Phospholipase D (PLD) is an essential enzyme responsible for the production of the lipid second messenger phosphatidic acid (PA), which is involved in fundamental cellular processes, including membrane trafficking, actin cytoskeleton remodeling, cell proliferation and cell survival. PLD activity can be stimulated by a large number of cell surface receptors and is elaborately regulated by intracellular factors, including protein kinase C isoforms, small GTPases of the ARF, Rho and Ras families and the phosphoinositide, phosphatidylinositol 4,5-bisphosphate (PIP2). The PLD-produced PA activates signaling proteins and acts as a node within the membrane to which signaling proteins translocate. Several signaling proteins, including Raf-1 and mTOR, directly bind PA to mediate translocation or activation, respectively.",
BMGC_PW1809,BMG_PW6670,,,
BMGC_PW1810,BMG_PW6671,,,
BMGC_PW1811,BMG_PW6672,,"During meiosis, a single round of DNA replication is followed by two rounds of chromosome segregation, called meiosis I and meiosis II. At meiosis I, homologous chromosomes recombine and then segregate to opposite poles, while the sister chromatids segregate from each other at meoisis II. In vertebrates, immature oocytes are arrested at the PI (prophase of meiosis I). The resumption of meiosis is stimulated by progesterone, which carries the oocyte through two consecutive M-phases (MI and MII) to a second arrest at MII. The key activity driving meiotic progression is the MPF (maturation-promoting factor), a heterodimer of CDC2 (cell division cycle 2 kinase) and cyclin B. In PI-arrested oocytes, MPF is initially inactive and is activated by the dual-specificity CDC25C phosphatase as the result of new synthesis of Mos induced by progesterone. MPF activation mediates the transition from the PI arrest to MI. The subsequent decrease in MPF levels, required to exit from MI into interkinesis, is induced by a negative feedback loop, where CDC2 brings about the activation of the APC (anaphase-promoting complex), which mediates destruction of cyclin B. Re-activation of MPF for MII requires re-accumulation of high levels of cyclin B as well as the inactivation of the APC by newly synthesized Emi2 and other components of the CSF (cytostatic factor), such as cyclin E or high levels of Mos. CSF antagonizes the ubiquitin ligase activity of the APC, preventing cyclin B destruction and meiotic exit until fertilization occurs. Fertilization triggers a transient increase in cytosolic free Ca2+, which leads to CSF inactivation and cyclin B destruction through the APC. Then eggs are released from MII into the first embryonic cell cycle.",
BMGC_PW1812,BMG_PW6673,,"p53 activation is induced by a number of stress signals, including DNA damage, oxidative stress and activated oncogenes. The p53 protein is employed as a transcriptional activator of p53-regulated genes. This results in three major outputs; cell cycle arrest, cellular senescence or apoptosis. Other p53-regulated gene functions communicate with adjacent cells, repair the damaged DNA or set up positive and negative feedback loops that enhance or attenuate the functions of the p53 protein and integrate these stress responses with other signal transduction pathways.",
BMGC_PW1813,BMG_PW6674,,"Protein ubiquitination plays an important role in eukaryotic cellular processes. It mainly functions as a signal for 26S proteasome dependent protein degradation. The addition of ubiquitin to proteins being degraded is performed by a reaction cascade consisting of three enzymes, named E1 (ubiquitin activating enzyme), E2 (ubiquitin conjugating enzyme), and E3 (ubiquitin ligase). Each E3 has specificity to its substrate, or proteins to be targeted by ubiquitination. Many E3s are discovered in eukaryotes and they are classified into four types: HECT type, U-box type, single RING-finger type, and multi-subunit RING-finger type. Multi-subunit RING-finger E3s are exemplified by cullin-Rbx E3s and APC/C. They consist of a RING-finger-containing subunit (RBX1 or RBX2) that functions to bind E2s, a scaffold-like cullin molecule, adaptor proteins, and a target recognizing subunit that binds substrates.",
BMGC_PW1814,BMG_PW6675,,"Ubiquitin and ubiquitin-like proteins (Ubls) are signalling messengers that control many cellular functions, such as cell proliferation, apoptosis, and DNA repair. It is suggested that Ub-protein modification evolved from prokaryotic sulfurtransfer systems. Molybdenum cofactor (Moco) and thiamin are sulfur-containing cofactors whose biosynthesis includes a key sulfur transfer step that uses unique sulfur carrier proteins, MoaD and ThiS. Ubiquitin, MoaD, and ThiS are all structurally related proteins whose C-termini are activated through adenylation by homologous E1-like enzymes. s2T biosynthesis may share similar chemistry with Moco and thiamin synthesis. In Saccharomyces cerevisiae, Urm1 and Uba4 function as part of a ubl protein conjugation system, though they have sequence homology to bacterial sulfur-transfer enzymes and the ability to function in sulfur transfer.",
BMGC_PW1815,BMG_PW6676,,,
BMGC_PW1816,BMG_PW6677,,"Lysosomes are membrane-delimited organelles in animal cells serving as the cell's main digestive compartment to which all sorts of macromolecules are delivered for degradation. They contain more than 40 hydrolases in an acidic environment (pH of about 5). After synthesis in the ER, lysosomal enzymes are decorated with mannose-6-phosphate residues, which are recognized by mannose-6-phosphate receptors in the trans-Golgi network. They are packaged into clathrin-coated vesicles and are transported to late endosomes. Substances for digestion are acquired by the lysosomes via a series of processes including endocytosis, phagocytosis, and autophagy.",
BMGC_PW1817,BMG_PW6678,,"Peroxisomes are essential organelles that play a key role in redox signalling and lipid homeostasis. They contribute to many crucial metabolic processes such as fatty acid oxidation, biosynthesis of ether lipids and free radical detoxification. The biogenesis of peroxisomes starts with the early peroxins PEX3, PEX16 and PEX19 and proceeds via several steps. The import of membrane proteins into peroxisomes needs PEX19 for recognition, targeting and insertion via docking at PEX3. Matrix proteins in the cytosol are recognized by peroxisomal targeting signals (PTS) and transported to the docking complex at the peroxisomal membrane. Peroxisomes' deficiencies lead to severe and often fatal inherited peroxisomal disorders (PD). PDs are usually classified in two groups. The first group is disorders of peroxisome biogenesis which include Zellweger syndrome, and the second group is single peroxisomal enzyme deficiencies.",
BMGC_PW1818,BMG_PW6679,,,
BMGC_PW1819,BMG_PW6680,,"Regulation of longevity depends on genetic and environmental factors. Caloric restriction (CR), that is limiting food intake, is recognized in mammals as the best characterized and most reproducible strategy for extending lifespan. Four pathways have been implicated in mediating the CR effect. These are the insulin like growth factor (IGF-1)/insulin signaling pathway, the sirtuin pathway, the adenosine monophosphate (AMP) activated protein kinase (AMPK) pathway and the target of rapamycin (TOR) pathway. The collective response of these pathways to CR is believed to promote cellular fitness and ultimately longevity via activation of autophagy, stress defense mechanisms, and survival pathways while attenuating proinflammatory mediators and cellular growth. Furthermore, there is evidence supporting that life span extension can be achieved with pharmacologic agents that mimic the effects of caloric restriction, such as rapamycin, via mTOR signaling blockade, resveratrol, by activating SIRT1 activity, and metformin, which seems to be a robust stimulator of AMPK activity. As an aging suppressor, Klotho is an important molecule in aging processes and its overexpression results in longevity.",
BMGC_PW1820,BMG_PW6681,,"Aging is a complex process of accumulation of molecular, cellular, and organ damage, leading to loss of function and increased vulnerability to disease and death. Despite the complexity of aging, recent work has shown that dietary restriction (DR) and genetic down-regulation of nutrient-sensing pathways, namely IIS (insulin/insulin-like growth factor signalling) and TOR (target-of- rapamycin) can substantially increase healthy life span of laboratory model organisms. These nutrient signaling pathways are conserved in various organisms. In worms, flies, and mammals, DR reduces signalling through IIS/TOR pathways, deactivating the PI3K/Akt/TOR intracellular signalling cascade and consequently activating the antiaging FOXO family transcription factor(s). In yeast, the effects of DR on life- span extension are associated with reduced activities of the TOR/Sch9 and Ras/PKA pathways and require the serine-threonine kinase Rim15 and transcription factors Gis1 and Msn2/4. These transcription factors (FOXO, DAF-16, Gis1, and Msn2/4) transactivate genes involved in resistance to oxidative stress, energy metabolism, DNA damage repair, glucose metabolism, autophagy and protection of proteins by chaperones.",
BMGC_PW1821,BMG_PW6682,,"Apoptosis is an evolutionarily conserved process used by multicellular organisms to developmentally regulate cell number or to eliminate cells that are potentially detrimental to the organism. The major players are caspases, caspase inhibitors, members of the Bcl-2 family of pro- and anti-apoptotic proteins and adaptors of the Ced-4/APAF-1 type. Mammals, by comparison with Caenorhabditis and Drosophila, exhibit highly complex extrinsic and intrinsic pathways for apoptosis induction. However, recent analyses of whole genome sequences from cnidarians (e.g. Hydra) suggest that the caspase and Bcl-2 families were already highly complex in cnidarians and that Caenorhabditis and Drosophila lost many of the genes involved in apoptosis.",
BMGC_PW1822,BMG_PW6683,,"Ferroptosis is a regulated form of cell death and characterized by a production of reactive oxygen species (ROS) from accumulated iron and lipid peroxidation. It can be induced by experimental compounds (e.g.,erastin, RSL3) or clinical drugs(e.g., sulfasalazine, sorafenib) in cancer cell and certain normal cells. It is involved in multiple physiological and pathological processes, such as cancer cell death, neurodegenerative disease, tissue damage and acute renal failure.",
BMGC_PW1823,BMG_PW6684,,"Contraction of the heart is a complex process initiated by the electrical excitation of cardiac myocytes (excitation-contraction coupling, ECC). In cardiac myocytes, Ca2+ influx induced by activation of voltage-dependent L-type Ca channels (DHP receptors) upon membrane depolarization triggers the release of Ca2+ via Ca2+ release channels (ryanodine receptors) of sarcoplasmic reticulum (SR) through a Ca2+ -induced Ca release (CICR) mechanism. Ca2+ ions released via the CICR mechanism diffuse through the cytosolic space to contractile proteins to bind to troponinC resulting in the release of inhibition induced by troponinI. The Ca2+ binding to troponinC thereby triggers the sliding of thin and thick filaments, that is, the activation of a crossbridge and subsequent cardiac force development and/or cell shortening. Recovery occurs as Ca2+ is pumped out of the cell by the Na+/Ca2+ exchanger (NCX) or is returned to the sarcoplasmic reticulum (SR) by sarco(endo)plasmic Ca2+ -ATPase (SERCA) pumps on the non-junctional region of the SR.",
BMGC_PW1824,BMG_PW6685,,"Cardiac myocytes express at least six subtypes of adrenergic receptor (AR) which include three subtypes of beta-AR (beta-1, beta-2, beta-3) and three subtypes of the alpha-1-AR (alpha-1A, alpha-1B, and alpha-1C). In the human heart the beta-1-AR is the pre- dominate receptor. Acute sympathetic stimulation of cardiac beta-1-ARs induces positive inotropic and chronotropic effects, the most effective mechanism to acutely increase output of the heart, by coupling to Gs, formation of cAMP by adenylyl cyclase (AC), and PKA- dependent phosphorylation of various target proteins (e.g., ryanodine receptor [RyR]; phospholamban [PLB], troponin I [TnI], and the L-type Ca2+ channel [LTCC]). Chronic beta-1-AR stimulation is detrimental and induces cardiomyocyte hypertrophy and apoptosis. beta-2-AR coupled to Gs exerts a proapoptotic action as well as beta-1-AR, while beta-2-AR coupled to Gi exerts an antiapoptotic action.",
BMGC_PW1825,BMG_PW6686,,"The vascular smooth muscle cell (VSMC) is a highly specialized cell whose principal function is contraction. On contraction, VSMCs shorten, thereby decreasing the diameter of a blood vessel to regulate the blood flow and pressure.              The principal mechanisms that regulate the contractile state of VSMCs are changes in cytosolic Ca2+ concentration ([Ca2+]c). In response to vasoconstrictor stimuli, Ca2+ is mobilized from intracellular stores and/or the extracellular space to increase [Ca2+]c in VSMCs. The increase in [Ca2+]c, in turn, activates the Ca2+-CaM-MLCK pathway and stimulates MLC20 phosphorylation, leading to myosin-actin interactions and, hence, the development of contractile force. The sensitivity of contractile myofilaments or MLC20 phosphorylation to Ca2+ can be secondarily modulated by other signaling pathways. During receptor stimulation, the contractile force is greatly enhanced by the inhibition of myosin phosphatase. Rho/Rho kinase, PKC, and arachidonic acid have been proposed to play a pivotal role in this enhancement.              The signaling events that mediate relaxation include the removal of a contractile agonist (passive relaxation) and activation of cyclic nucleotide-dependent signaling pathways in the continued presence of a contractile agonist (active relaxation). Active relaxation occurs through the inhibition of both Ca2+ mobilization and myofilament Ca2+ sensitivity in VSMCs.",
BMGC_PW1826,BMG_PW6687,,"Apelin is an endogenous peptide capable of binding the apelin receptor (APJ), which was originally described as an orphan G-protein-coupled receptor. Apelin and APJ are widely expressed in various tissues and organ systems. They are implicated in different key physiological processes such as angiogenesis, cardiovascular functions, cell proliferation and energy metabolism regulation. On the other hand, this ligand receptor couple is also involved in several pathologies including diabetes, obesity, cardiovascular disease and cancer.",
BMGC_PW1827,BMG_PW6688,,"The osteoclasts, multinucleared cells originating from the hematopoietic monocyte-macrophage lineage, are responsible for bone resorption. Osteoclastogenesis is mainly regulated by signaling pathways activated by RANK and immune receptors, whose ligands are expressed on the surface of osteoblasts. Signaling from RANK changes gene expression patterns through transcription factors like NFATc1 and characterizes the active osteoclast.",
BMGC_PW1828,BMG_PW6689,,"The extracellular matrix (ECM) consists of a complex mixture of structural and functional macromolecules and serves an important role in tissue and organ morphogenesis and in the maintenance of cell and tissue structure and function. Specific interactions between cells and the ECM are mediated by transmembrane molecules, mainly integrins and perhaps also proteoglycans, CD36, or other cell-surface-associated components. These interactions lead to a direct or indirect control of cellular activities such as adhesion, migration, differentiation, proliferation, and apoptosis. In addition, integrins function as mechanoreceptors and provide a force-transmitting physical link between the ECM and the cytoskeleton. Integrins are a family of glycosylated, heterodimeric transmembrane adhesion receptors that consist of noncovalently bound alpha- and beta-subunits.",
BMGC_PW1829,BMG_PW6690,,"Cell adhesion molecules (CAMs) are (glyco)proteins expressed on the cell surface and play a critical role in a wide array of biologic processes that include hemostasis, the immune response, inflammation, embryogenesis, and development of neuronal tissue. There are four main groups: the integrin family, the immunoglobulin superfamily, selectins, and cadherins. Membrane proteins that mediate immune cell&#8211;cell interactions fall into different categories, namely those involved in antigen recognition, costimulation and cellular adhesion. Furthermore cell-cell adhesions are important for brain morphology and highly coordinated brain functions such as memory and learning. During early development of the nervous system, neurons elongate their axons towards their targets and establish and maintain synapses through formation of cell-cell adhesions. Cell-cell adhesions also underpin axon-axon contacts and link neurons with supporting schwann cells and oligodendrocytes.",
BMGC_PW1830,BMG_PW6691,,"Gap junctions contain intercellular channels that allow direct communication between the cytosolic compartments of adjacent cells. Each gap junction channel is formed by docking of two 'hemichannels', each containing six connexins, contributed by each neighboring cell. These channels permit the direct transfer of small molecules including ions, amino acids, nucleotides, second messengers and other metabolites between adjacent cells. Gap junctional communication is essential for many physiological events, including embryonic development, electrical coupling, metabolic transport, apoptosis, and tissue homeostasis. Communication through Gap Junction is sensitive to a variety of stimuli, including changes in the level of intracellular Ca2+, pH, transjunctional applied voltage and phosphorylation/dephosphorylation processes. This figure represents the possible activation routes of different protein kinases involved in Cx43 and Cx36 phosphorylation.",
BMGC_PW1831,BMG_PW6692,,"Pluripotent stem cells (PSCs) are basic cells with an indefinite self-renewal capacity and the potential to generate all the cell types of the three germinal layers. The types of PSCs known to date include embryonic stem (ES) and induced pluripotent stem (iPS) cells. ES cells are derived from the inner cell mass (ICM) of blastocyst-stage embryos. iPS cells are generated by reprogramming somatic cells back to pluripotent state with defined reprogramming factors, Oct4, Sox2, Klf4 and c-Myc (also known as Yamanaka factors). PSCs including ES cells and iPS cells are categorized into two groups by their morphology, gene expression profile and external signal dependence. Conventional mouse-type ES/iPS cells are called 'naive state' cells. They are mainly maintained under the control of LIF and BMP signaling. On the other hand, human-type ES/iPS cells, which are in need of Activin and FGF signaling, are termed 'primed state'. However, these signaling pathways converge towards the activation of a core transcriptional network that is similar in both groups and involves OCt4, Nanog and Sox2. The three transcription factors and their downstream target genes coordinately promote self-renewal and pluripotency.",
BMGC_PW1832,BMG_PW6693,,"Platelets play a key and beneficial role for primary hemostasis on the disruption of the integrity of vessel wall. Platelet adhesion and activation at sites of vascular wall injury is initiated by adhesion to adhesive macromolecules, such as collagen and von Willebrand factor (vWF), or by soluble platelet agonists, such as ADP, thrombin, and thromboxane A2. Different receptors are stimulated by various agonists, almost converging in increasing intracellular Ca2+ concentration that stimulate platelet shape change and granule secretion and ultimately induce the ""inside-out"" signaling process leading to activation of the ligand-binding function of integrin alpha IIb beta 3. Binding of alpha IIb beta 3 to its ligands, mainly fibrinogen, mediates platelet adhesion and aggregation and triggers ""outside-in"" signaling, resulting in platelet spreading, additional granule secretion, stabilization of platelet adhesion and aggregation, and clot retraction.",
BMGC_PW1833,BMG_PW6694,,"Neutrophils play a central role in innate immune defense. One of the mechanisms of neutrophil action is the formation of neutrophil extracellular traps (NETs), the extracellular structures composed of chromatin coated with histones, proteases and granular and cytosolic proteins that help catch and kill microorganisms. NETs are formed by a process known as ""NETosis"" that can be triggered by microorganisms and endogenous stimuli, such as damage-associated molecular patterns and immune complexes, and involves activation in most cases of nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase, which produces reactive oxygen species (ROS). Recent study has reported that there are two different mechanisms of NETosis, including a lytic NETosis and a vital NETosis. Lytic NETosis begins with nuclear delobulation and the disassembly of the nuclear envelope and continues with loss of cellular polarization, chromatin decondensation and plasma membrane rupture. Vital NETosis can occur independently of cell death and involves the secreted expulsion of nuclear chromatin that is accompanied by the release of granule proteins through degranulation.",
BMGC_PW1834,BMG_PW6695,,"The renin-angiotensin system (RAS) is a peptidergic system with endocrine characteristics regarding to the regulation of the blood pressure and hydro-electrolytic balance. In the classical RAS, the enzyme renin cleaves its substrate angiotensinogen (Agt) forming the decapeptide angiotensin I that is in turn cleaved by angiotensin-converting enzyme (ACE) to produce the angiotensin II (Ang II), a key player of this system. Ang II activates its AT1 receptor (AT1R), the principal receptor that mediates the majority of the known actions of Ang II in the kidney, including vasoconstriction, renal sodium (Na+) reabsorption, and aldosterone secretion, increasing blood pressure and contributing to the development of hypertension. In addition to (ACE)/Ang II/AT1R and AT2R axis, other signaling pathways in the RAS, such as ACE2/angiotensin-(1-7)/Mas and Ang IV/IRAP, and other active peptide of the RAS, with physiological relevance as Ang III, Ang A and alamandine, are now widely recognized.",
BMGC_PW1835,BMG_PW6696,,"Specific families of pattern recognition receptors are responsible for detecting foreign DNA from invading microbes or host cells and generating innate immune responses. DAI is the first identified sensor of cytosolic DNA which activates the IRF and NF-{kappa}B transcription factors, leading to production of type I interferon and other cytokines. The second type of cytoplasmic DNA sensor is AIM2. Upon sensing DNA, AIM2 triggers the assembly of the inflammasome, culminating in interleukin maturation. In addition to these receptors, there is a mechanism to sense foreign DNA, with the host RNA polymerase III converting the DNA into RNA for recognition by the RNA sensor RIG-I. These pathways provide various means to alert the cell.",
BMGC_PW1836,BMG_PW6697,,"C-type lectin receptors (CLRs) are a large superfamily of proteins characterized by the presence of one or more C-type lectin-like domains (CTLDs). CLRs function as pattern-recognition receptors (PRRs) for pathogen-derived ligands in dendric cells, macrophages, neutrophils, etc., such as Dectin-1 and Dectin-2 for recognition of fungi-derived B-glucan and high mannose-type carbohydrates. Upon ligand binding, CLRs stimulate intracellular signaling cascades that induce the production of inflammatory cytokines and chemokines, consequently triggering innate and adaptive immunity to pathogens.",
BMGC_PW1837,BMG_PW6698,,"Blood-cell development progresses from a hematopoietic stem cell (HSC), which can undergo either self-renewal or differentiation into a multilineage committed progenitor cell: a common lymphoid progenitor (CLP) or a common myeloid progenitor (CMP). A CLP gives rise to the lymphoid lineage of white blood cells or leukocytes-the natural killer (NK) cells and the T and B lymphocytes. A CMP gives rise to the myeloid lineage, which comprises the rest of the leukocytes, the erythrocytes (red blood cells), and the megakaryocytes that produce platelets important in blood clotting. Cells undergoing these differentiation process express a stage- and lineage-specific set of surface markers. Therefore cellular stages are identified by the specific expression patterns of these genes.",
BMGC_PW1838,BMG_PW6699,,"Natural killer (NK) cells are lymphocytes of the innate immune system that are involved in early defenses against both allogeneic (nonself) cells and autologous cells undergoing various forms of stress, such as infection with viruses, bacteria, or parasites or malignant transformation. Although NK cells do not express classical antigen receptors of the immunoglobulin gene family, such as the antibodies produced by B cells or the T cell receptor expressed by T cells, they are equipped with various receptors whose engagement allows them to discriminate between target and nontarget cells. Activating receptors bind ligands on the target cell surface and trigger NK cell activation and target cell lysis. However Inhibitory receptors recognize MHC class I molecules (HLA) and inhibit killing by NK cells by overruling the actions of the activating receptors. This inhibitory signal is lost when the target cells do not express MHC class I and perhaps also in cells infected with virus, which might inhibit MHC class I exprssion or alter its conformation. The mechanism of NK cell killing is the same as that used by the cytotoxic T cells generated in an adaptive immune response; cytotoxic granules are released onto the surface of the bound target cell, and the effector proteins they contain penetrate the cell membrane and induce programmed cell death.",
BMGC_PW1839,BMG_PW6700,,"Immunity to different classes of microorganisms is orchestrated by separate lineages of effector T helper (TH)-cells, which differentiate from naive CD4+ precursor cells in response to cues provided by antigen presenting cells (APC) and include T helper type 1 (Th1) and Th2. Th1 cells are characterized by the transcription factor T-bet and signal transducer and activator of transcription (STAT) 4, and the production of IFN-gamma. These cells stimulate strong cell-mediated immune responses, particularly against intracellular pathogens. On the other hand, transcription factors like GATA-3 and STAT6 drive the generation of Th2 cells that produce IL-4, IL-5 and IL-13 and are necessary for inducing the humoral response to combat parasitic helminths (type 2 immunity) and isotype switching to IgG1 and IgE. The balance between Th1/Th2 subsets determines the susceptibility to disease states, where the improper development of Th2 cells can lead to allergy, while an overactive Th1 response can lead to autoimmunity.",
BMGC_PW1840,BMG_PW6701,,"Interleukin (IL)-17-producing helper T (Th17) cells serve as a subset of CD4+ T cells involved in epithelial cell- and neutrophil mediated immune responses against extracellular microbes and in the pathogenesis of autoimmune diseases. In vivo, Th17 differentiation requires antigen presentation and co-stimulation, and activation of antigen presenting-cells (APCs) to produce TGF-beta, IL-6, IL-1, IL-23 and IL-21. This initial activation results in the activation and up-regulation of STAT3, ROR(gamma)t and other transcriptional factors in CD4+ T cells, which bind to the promoter regions of the IL-17, IL-21 and IL-22 genes and induce IL-17, IL-21 and IL-22. In contrast, the differentiation of Th17 cells and their IL-17 expression are negatively regulated by IL-2, Th2 cytokine IL-4, IL-27 and Th1 cytokine IFN-gamma through STAT5, STAT6 and STAT1 activation, respectively. Retinoid acid and the combination of IL-2 and TGF-beta upregulate Foxp3, which also downregulates cytokines like IL-17 and IL-21. The inhibition of Th17 differentiation may serve as a protective strategy to 'fine-tune' the expression IL-17 so it does not cause excessive inflammation. Thus, balanced differentiation of Th cells is crucial for immunity and host protection.",
BMGC_PW1841,BMG_PW6702,,"Leukocyte migaration from the blood into tissues is vital for immune surveillance and inflammation. During this diapedesis of leukocytes, the leukocytes bind to endothelial cell adhesion molecules (CAM) and then migrate across the vascular endothelium. A leukocyte adherent to CAMs on the endothelial cells moves forward by leading-edge protrusion and retraction of its tail. In this process, alphaL /beta2 integrin activates through Vav1, RhoA, which subsequently activates the kinase p160ROCK. ROCK activation leads to MLC phosphorylation, resulting in retraction of the actin cytoskeleton. Moreover, Leukocytes activate endothelial cell signals that stimulate endothelial cell retraction during localized dissociation of the endothelial cell junctions. ICAM-1-mediated signals activate an endothelial cell calcium flux and PKC, which are required for ICAM-1 dependent leukocyte migration. VCAM-1 is involved in the opening of the ""endothelial passage"" through which leukocytes can extravasate. In this regard, VCAM-1 ligation induces NADPH oxidase activation and the production of reactive oxygen species (ROS) in a Rac-mediated manner, with subsequent activation of matrix metallopoteinases and loss of VE-cadherin-mediated adhesion.",
BMGC_PW1842,BMG_PW6703,,"The intestine is the largest lymphoid tissue in the body. One striking feature of intestinal immunity is its ability to generate great amounts of noninflammatory immunoglobulin A (IgA) antibodies that serve as the first line of defense against microorganisms. The basic map of IgA production includes induction of mucosal B cells in the Peyer's patches, circulation through the bloodstream and homing to intestinal mucosa of IgA-commited plasma cells, and local antibody production for export across the intestinal membranes. Multiple cytokines, including TGF-{beta}, IL-10, IL-4, IL-5, and IL-6, are required to promote IgA class switching and terminal differentiation process of the B cells. Secreted IgA promotes immune exclusion by entrapping dietary antigens and microorganisms in the mucus and functions for neutralization of toxins and pathogenic microbes.",
BMGC_PW1843,BMG_PW6704,,"Circadian rhythm is an internal biological clock, which enables to sustain an approximately 24-hour rhythm in the absence of environmental cues. In mammals, the circadian clock mechanism consists of cell-autonomous transcription-translation feedback loops that drive rhythmic, 24-hour expression patterns of core clock components. The first negative feedback loop is a rhythmic transcription of period genes (PER1, PER2, and PER3) and chryptochrome genes (CRY1 and CRY2). PER and CRY proteins form a heterodimer, which acts on the CLOCK/BMAL1 heterodimer to repress its own transcription. PER and CRY proteins are phosphorylated by casein kinase epsilon (CKIepsilon), which leads to degradation and restarting of the cycle. The second loop is a positive feedback loop driven by the CLOCK/BMAL1 heterodimer, which initiates transcription of target genes containing E-box cis-regulatory enhancer sequences.",
BMGC_PW1844,BMG_PW6705,,"Circadian entrainment is a fundamental property by which the period of the internal biological clock is entrained by recurring exogenous signals, such that the organism's endocrine and behavioral rhythms are synchronized to environmental cues. In mammals, a master clock is located in the suprachiasmatic nuclei (SCN) of the hypothalamus and may synchronize circadian oscillators in peripheral tissues. Light signal is the dominant synchronizer for master SCN clock. Downstream from the retina, glutamate and PACAP are released and trigger the activation of signal transduction cascades, including CamKII and nNOS activity, cAMP- and cGMP-dependent protein kinases, and mitogen-activated protein kinase (MAPK). Of non-photic entrainment, important phase shifting capabilities have been found for melatonin, which inhibits light-induced phase shifts through inhibition of adenylate cyclase (AC). Multiple entrainment pathways converge into CREB regulation. In turn, phosphorylated CREB activates clock gene expression.",
BMGC_PW1845,BMG_PW6706,,"Thermogenesis is essential for warm-blooded animals, ensuring normal cellular and physiological function under conditions of environmental challenge. Thermogenesis in brown and beige adipose tissue is mainly controlled by norepinephrine, which is released from sympathetic nervous system in response to cold or dietary stimuli. The mitochondrial uncoupling protein 1 (UCP1) is responsible for the process whereby chemical energy is converted into heat in these adipocytes. Activation of these adipocytes leads to an increase in calorie consumption and is expected to improve overweight conditions, providing a potential strategy for treating obesity and its related metabolic disorders.",
BMGC_PW1846,BMG_PW6707,,"Neurotrophins are a family of trophic factors involved in differentiation and survival of neural cells. The neurotrophin family consists of nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and neurotrophin 4 (NT-4). Neurotrophins exert their functions through engagement of Trk tyrosine kinase receptors or p75 neurotrophin receptor (p75NTR). Neurotrophin/Trk signaling is regulated by connecting a variety of intracellular signaling cascades, which include MAPK pathway, PI-3 kinase pathway, and PLC pathway, transmitting positive signals like enhanced survival and growth. On the other hand, p75NTR transmits both positive and nagative signals. These signals play an important role for neural development and additional higher-order activities such as learning and memory.",
BMGC_PW1847,BMG_PW6708,,"Serotonin (5-Hydroxytryptamine, 5-HT) is a monoamine neurotransmitter that plays important roles in physiological functions such as learning and memory, emotion, sleep, pain, motor function and endocrine secretion, as well as in pathological states including abnormal mood and cognition. Once released from presynaptic axonal terminals, 5-HT binds to receptors, which have been divided into 7 subfamilies on the basis of conserved structures and signaling mechanisms. These families include the ionotropic 5-HT3 receptors and G-protein-coupled 5-HT receptors, the 5-HT1 (Gi /Go -coupled), 5-HT2(Gq-coupled), 5-HT4/6/7 (Gs-coupled) and 5-HT5 receptors. Presynaptically localized 5-HT1B receptors are thought to be the autoreceptors that suppress excess 5-HT release. 5-HT's actions are terminated by transporter- mediated reuptake into neurons, leading to catabolism by monoamine oxidase.",
BMGC_PW1848,BMG_PW6709,,"Five basic tastes are recognized by humans and most other animals - bitter, sweet, sour, salty and umami. In vertebrates, taste stimuli are detected by taste receptor cells (TRCs). At least three distinct cell types are found in mammalian taste buds : type I cells, type II cells, and type III cells. Type I cells express epithelial sodium channel (ENaC) and are considered to be the major mediator of perception of low salt. In type II cells, transduction of bitter, sweet and umami is mediated by a canonical PLC-beta/IP3-signaling cascade, which culminates in the opening of the TRPM5 ion channel. This produces a depolarization that may allow CALMH1 channels to open and release ATP, which serves as a neurotransmitter to activate closely associated nerve afferents expressing P2X2, P2X3 receptors and adjacent type III cells expressing P2Y4 receptors. Type II taste cells also secrete acetylcholine (ACh) that appears to stimulate muscarinic receptors, specifically M3, on the same or neighboring Type II cells. This muscarinic feedback augments taste-evoked release of ATP. In type III cells, sour taste is initiated when protons enter through apically located proton-selective ion channels: polycystic kidney disease 2-like 1 protein (PKD2L1) and polycystic kidney disease 1-like 3 protein (PKD1L3) channels. Weak acids may also activate sour cells by penetrating the cell membrane and leading to closure of resting K+ channels and membrane depolarization. Further, voltage-gated Ca2+ channels are activated and release vesicular serotonin (5-HT), norepinephrine (NE) and gamma-aminobutyric acid (GABA). 5-HT and GABA provide negative paracrine feedback onto receptor cells by activating 5-HT1A and GABAA, GABAB receptors, respectively. 5-HT also functions as a transmitter between presynaptic cells and the sensory afferent.",
BMGC_PW1849,BMG_PW6710,,"The TRP channels that exhibit a unique response to temperature have been given the name thermo-TRPs. Among all thermo- TRP channels, TRPV1-4, TRPM8, and TRPA1 are expressed in subsets of nociceptive dorsal root ganglion (DRG) neuron cell bodies including their peripheral and central projections. These channels can be modulated indirectly by inflammatory mediators such as PGE2, bradykinin, ATP, NGF, and proinflammatory cytokines that are generated during tissue injury. While the noxious heat receptor TRPV1 is sensitized (that is, their excitability can be increased) by post-translational modifications upon activation of G-protein coupled receptors (GPCRs) or tyrosine kinase receptors, the receptors for inflammatory mediators, the same action appears to mainly desensitize TRPM8, the main somatic innocuous cold sensor. This aforementioned sensitization could allow the receptor to become active at body temperature, so it not only contributes toward thermal hypersensitivity but also is possibly a substrate for ongoing persistent pain.",
BMGC_PW1850,BMG_PW6713,,"Insulin binding to its receptor results in the tyrosine phosphorylation of insulin receptor substrates (IRS) by the insulin receptor tyrosine kinase (INSR). This allows association of IRSs with the regulatory subunit of phosphoinositide 3-kinase (PI3K). PI3K activates 3-phosphoinositide-dependent protein kinase 1 (PDK1), which activates Akt, a serine kinase. Akt in turn deactivates glycogen synthase kinase 3 (GSK-3), leading to activation of glycogen synthase (GYS) and thus glycogen synthesis. Activation of Akt also results in the translocation of GLUT4 vesicles from their intracellular pool to the plasma membrane, where they allow uptake of glucose into the cell. Akt also leads to mTOR-mediated activation of protein synthesis by eIF4 and p70S6K. The translocation of GLUT4 protein is also elicited through the CAP/Cbl/TC10 pathway, once Cbl is phosphorylated by INSR.             Other signal transduction proteins interact with IRS including GRB2. GRB2 is part of the cascade including SOS, RAS, RAF and MEK that leads to activation of mitogen-activated protein kinase (MAPK) and mitogenic responses in the form of gene transcription. SHC is another substrate of INSR. When tyrosine phosphorylated, SHC associates with GRB2 and can thus activate the RAS/MAPK pathway independently of IRS-1.",
BMGC_PW1851,BMG_PW6714,,"Gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus acts upon its receptor in the anterior pituitary to regulate the production and release of the gonadotropins, LH and FSH. The GnRHR is coupled to Gq/11 proteins to activate phospholipase C which transmits its signal to diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3). DAG activates the intracellular protein kinase C (PKC) pathway and IP3 stimulates release of intracellular calcium. In addition to the classical Gq/11, coupling of Gs is occasionally observed in a cell-specific fashion. Signaling downstream of protein kinase C (PKC) leads to transactivation of the epidermal growth factor (EGF) receptor and activation of mitogen-activated protein kinases (MAPKs), including extracellular-signal-regulated kinase (ERK), Jun N-terminal kinase (JNK) and p38 MAPK. Active MAPKs translocate to the nucleus, resulting in activation of transcription factors and rapid induction of early genes.",
BMGC_PW1852,BMG_PW6715,,"The ovarian steroids, 17-beta estradiol (E2) and progesterone (P4), are critical for normal uterine function, establishment and maintenance of pregnancy, and mammary gland development. Furthermore, the local effects that are essential for normal ovarian physiology are dependent on the endocrine, paracrine, and autocrine actions of E2, P4, and androgens. In most mammals (including humans and mice), ovarian steroidogenesis occurs according to the two-cell/two-gonadotropin theory. This theory describes how granulosa and theca cells work together to make the ovarian steroids. Theca cells respond to LH signaling by increasing the expression of enzymes necessary for the conversion of cholesterol to androgens, such as androstenedione (A) and testosterone (T). Granulosa cells respond to FSH signaling by increasing the expression of enzymes necessary for the conversion of theca-derived androgens into estrogens (E2 and estrone).",
BMGC_PW1853,BMG_PW6716,,"Xenopus oocytes are naturally arrested at G2 of meiosis I. Exposure to either insulin/IGF-1 or the steroid hormone progesterone breaks this arrest and induces resumption of the two meiotic division cycles and maturation of the oocyte into a mature, fertilizable egg. This process is termed oocyte maturation. The transition is accompanied by an increase in maturation promoting factor (MPF or Cdc2/cyclin B) which precedes germinal vesicle breakdown (GVBD). Most reports point towards the Mos-MEK1-ERK2 pathway [where ERK is an extracellular signal-related protein kinase, MEK is a MAPK/ERK kinase and Mos is a p42(MAPK) activator] and the polo-like kinase/CDC25 pathway as responsible for the activation of MPF in meiosis, most likely triggered by a decrease in cAMP.",
BMGC_PW1854,BMG_PW6717,,"The thyroid hormones (THs) are important regulators of growth, development and metabolism. The action of TH is mainly mediated by T3 (3,5,3'-triiodo-L-thyronine). Thyroid hormones, L-thyroxine (T4) and T3 enter the cell through transporter proteins. Although the major form of TH in the blood is T4, it is converted to the more active hormone T3 within cells. T3 binds to nuclear thyroid hormone receptors (TRs), which functions as a ligand-dependent transcription factor and controls the expression of target genes (genomic action). Nongenomic mechanisms of action is initiated at the integrin receptor. The plasma membrane alpha(v)beta(3)-integrin has distinct binding sites for T3 and T4. One binding site binds only T3 and activates the phosphatidylinositol 3-kinase (PI3K) pathway. The other binding site binds both T3 and T4 and activates the ERK1/2 MAP kinase pathway.",
BMGC_PW1855,BMG_PW6718,,"Increased adipocyte volume and number are positively correlated with leptin production, and negatively correlated with production of adiponectin.             Leptin is an important regulator of energy intake and metabolic rate primarily by acting at hypothalamic nuclei. Leptin exerts its anorectic effects by modulating the levels of neuropeptides such as NPY, AGRP, and alpha-MSH. This leptin action is through the JAK kinase, STAT3 phosphorylation, and nuclear transcriptional effect.             Adiponectin lowers plasma glucose and FFAs. These effects are partly accounted for by adiponectin-induced AMPK activation, which in turn stimulates skeletal muscle fatty acid oxidation and glucose uptake. Furthermore, activation of AMPK by adiponectin suppresses endogenous glucose production, concomitantly with inhibition of PEPCK and G6Pase expression.             The proinflammatory cytokine TNFalpha has been implicated as a link between obesity and insulin resistance. TNFalpha interferes with early steps of insulin signaling. Several data have shown that TNFalpha inhibits IRS1 tyrosine phosphorylation by promoting its serine phosphorylation. Among the serine/threonine kinases activated by TNFalpha, JNK, mTOR and IKK have been shown to be involved in this phosphorylation.",
BMGC_PW1856,BMG_PW6719,,"Lipolysis in adipocytes, the hydrolysis of triacylglycerol (TAG) to release fatty acids (FAs) and glycerol for use by other organs as energy substrates, is a unique function of white adipose tissue. Lipolysis is under tight hormonal control. During fasting, catecholamines, by binding to Gs-coupled-adrenergic receptors (-AR), activate adenylate cyclase (AC) to increase cAMP and activate protein kinase A (PKA). PKA phosphorylates target protein such as hormone-sensitive lipase (HSL) and perilipin 1 (PLIN). PLIN phosphorylation is a key event in the sequential activation of TAG hydrolysis involving adipose triglyceride lipase (ATGL), HSL, and monoglyceride lipase (MGL). During the fed state, insulin, through activation of phosphodiesterase-3B (PDE-3B), inhibits catecholamine-induced lipolysis via the degradation of cAMP.",
BMGC_PW1857,BMG_PW6720,,"The aspartyl-protease renin is the key regulator of the renin-angiotensin-aldosterone system, which is critically involved in extracellular fluid volume and blood pressure homeostasis of the body. Renin is synthesized, stored in, and released into circulation by the juxtaglomerular (JG) cells of the kidney. Secretion of renin from JG cells at the organ level is controlled by the four main mechanisms: the sympathetic nervous system, the local JG apparatus baroreflex, the macula densa mechanism, and several hormones acting locally within the JG apparatus. Renin secretion at the level of renal JG cells appears to be controlled mainly by classic second messengers, namely cAMP, cGMP, and free cytosolic calcium concentration. While cAMP generally stimulates renin release and the intracellular calcium concentration suppresses the exocytosis of renin, the effects of cGMP in the regulation of the renin system are more complex as it both may stimulate or inhibit renin release.",
BMGC_PW1858,BMG_PW6721,,"Aldosterone is a steroid hormone synthesized in and secreted from the outer layer of the adrenal cortex, the zona glomerulosa. Aldosterone plays an important role in the regulation of systemic blood pressure through the absorption of sodium and water. Angiotensin II (Ang II), potassium (K+) and adrenocorticotropin (ACTH) are the main extracellular stimuli which regulate aldosterone secretion. These physiological agonists all converge on two major intracellular signaling pathways: calcium (Ca2+) mobilization and an increase in cAMP production. The increase in cytosolic calcium levels activates calcium/calmodulin- dependent protein kinases (CaMK), and the increased cAMP levels stimulate the activity of cAMP-dependent protein kinase, or protein kinase A (PKA). The activated CaMK, and possibly PKA, activates transcription factors (NURR1 and NGF1B, CREB) to induce StAR and CYP11B2 expression, the early and late rate- limiting steps in aldosterone biosynthesis, respectively, thereby stimulating aldosterone secretion.",
BMGC_PW1859,BMG_PW6722,,"Human relaxin-2 (""relaxin""), originally identified as a peptidic hormone of pregnancy, is now known to exert a range of pleiotropic effects including vasodilatory, anti-fibrotic and angiogenic effects in both males and females. It belongs to the so-called relaxin peptide family which includes the insulin-like peptides INSL3 and INSL5, and relaxin-3 (H3) as well as relaxin. INSL3 has clearly defined specialist roles in male and female reproduction, relaxin-3 is primarily a neuropeptide involved in stress and metabolic control, and INSL5 is widely distributed particularly in the gastrointestinal tract. These members of relaxin peptide family exert such effects binding to different kinds of receptors, classified as relaxin family peptide (RXFP) receptors: RXFP1, RXFP2, RXFP3, and RXFP4. These G protein-coupled receptors predominantly bind relaxin, INSL3, relaxin-3, and INSL-5, respectively. RXFP1 activates a wide spectrum of signaling pathways to generate second messengers that include cAMP and nitric oxide, whereas RXFP2 activates a subset of these pathways. Both RXFP3 and RXFP4 inhibit cAMP production, and RXFP3 activate MAP kinases.",
BMGC_PW1860,BMG_PW6723,,"Cortisol is the main endogenous glucocorticoid, which affects a plethora of physiological functions, e.g., lipid and glucose metabolism, metabolic homeostasis and adaptation to stress. Cortisol production is primarily regulated by corticotropin (ACTH) in zona fasciculata. The stimulatory effect of ACTH on cortisol synthesis depends on cAMP dependent signaling, but also involves membrane depolarization and increased cytosolic Ca2+. Each of cAMP and Ca2+ induces the expression of StAR, stimulating intramitochondrial cholesterol transfer, as well as the steroidogenic enzymes in the pathway from cholesterol to cortisol (e.g., CHE, CYP17A1, CYP11B1).",
BMGC_PW1861,BMG_PW6724,,"Parathyroid hormone (PTH) is a key regulator of calcium and phosphorus homeostasis. The principal regulators of PTH secretion are extracellular ionized calcium (Ca2+) and 1,25-dihydroxyvitamin D (1,25(OH)2D3). Under conditions of dietary Ca restriction, a decrement in serum Ca concentration induces release of PTH from the parathyroid gland. PTH acts on bone and kidney to stimulate bone turnover, increase the circulating levels of 1,25(OH)2D3 and calcium and inhibit the reabsorption of phosphate from the glomerular filtrate. This hormone exerts its actions via binding to the PTH/PTH-related peptide receptor (PTH1R). PTH1R primarily activates two sub-types of heterotrimeric Gproteins: Gs and Gq , which in turn regulate the activity of adenylyl cyclases and phospholipase C (PLC) that control the flow of cAMP/PKA and IP/PKC signaling cascades, respectively.",
BMGC_PW1862,BMG_PW6725,,"Hypothalamic gonadotropin-releasing hormone (GnRH) neurons are key regulators of reproduction. They release GnRH into the portal circulation. In turn, GnRH stimulates the pituitary gland to secrete follicle-stimulating hormone and luteinizing hormone (LH) to regulate gonadal functions. Gonadal steroids provide feedback to regulate GnRH release. GnRH neurons express the kisspeptin receptor, GPR 54, and kisspeptins potently stimulate the release of GnRH by depolarising and inducing sustained action potential firing in GnRH neurons. It is also demonstrated that Kisspeptin-GPR54 system positively regulates the GnRH expression  with a time course consistent with activation of Akt and MAP kinase signaling pathways.",
BMGC_PW1863,BMG_PW6726,,"Insulin resistance is a condition where cells become resistant to the effects of insulin. It is often found in people with health disorders, including obesity, type 2 diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. In this diagram multiple mechanisms underlying insulin resistance are shown: (a) increased phosphorylation of IRS (insulin receptor substrate) protein through serine/threonine kinases, such as JNK1 and IKKB, and protein kinase C, (b) increased IRS-1 proteasome degradation via mTOR signaling pathway, (c) decreased activation of signaling molecules including PI3K and AKT, (d) increase in activity of phosphatases including PTPs, PTEN, and PP2A. Regulatory actions such as oxidative stress, mitochondrial dysfunction, accumulation of intracellular lipid derivatives (diacylglycrol and ceramides), and inflammation (via IL-6 and TNFA) contribute to these mechanisms. Consequently, insulin resistance causes reduced GLUT4 translocation, resulting in glucose takeup and glycogen synthesis in skeletal muscle as well as increased hepatic gluconeogenesis and decreased glycogen synthesis in liver. At the bottom of the diagram, interplay between O-GlcNAcylation and serine/threonine phosphorylation is shown. Studies suggested that elevated O-GlcNAc level was correlated to high glucose-induced insulin resistance. Donor UDP-GlcNAc is induced through hexosamine biosynthesis pathway and added to proteins by O-GlcNAc transferase. Elevation of O-GlcNAc modification alters phosphorylation and function of key insulin signaling proteins including IRS-1, PI3K, PDK1, Akt and other transcription factor and cofactors, resulting in the attenuation of insulin signaling cascade.",
BMGC_PW1864,BMG_PW6727,,"Non-alcoholic fatty liver disease (NAFLD) represents a spectrum ranging from simple steatosis to more severe steatohepatitis with hepatic inflammation and fibrosis, known as nonalcoholic steatohepatitis (NASH). NASH may further lead to cirrhosis and hepatocellular carcinoma (HCC). This map shows a stage-dependent progression of NAFLD. In the first stage of NAFLD, excess lipid accumulation has been demonstrated. The main cause is the induction of insulin resistance, which leads to a defect in insulin suppression of free fatty acids (FAAs) disposal. In addition, two transcription factors, SREBP-1c and PPAR-alpha, activate key enzymes of lipogenesis and increase the synthesis of FAAs in liver. In the second stage, as a consequence of the progression to NASH, the production of reactive oxygen species (ROS) is enhanced due to oxidation stress through mitochondrial beta-oxidation of fatty acids and endoplamic reticulum (ER) stress, leading to lipid peroxidation. The lipid peroxidation can further cause the production of cytokines (Fas ligand, TNF-alpha, IL-8 and TGF), promoting cell death, inflammation and fibrosis. The activation of JNK, which is induced by ER stress, TNF-alpha and FAAs, is also associated with NAFLD progression. Increased JNK promotes cytokine production and initiation of HCC.",
BMGC_PW1865,BMG_PW6728,,"Advanced glycation end products (AGEs) are a complex group of compounds produced through the non-enzymatic glycation and oxidation of proteins, lipids and nucleic acids, primarily due to aging and under certain pathologic condition such as huperglycemia. Some of the best chemically characterized AGEs include N-epsilon-carboxy-methyl-lysine (CML), N-epsilon-carboxy-ethyl-lysine (CEL), and Imidazolone. The major receptor for AGEs, known as receptor for advanced glycation end products (RAGE or AGER), belongs to the immunoglobulin superfamily and has been described as a pattern recognition receptor. AGE/RAGE signaling elicits activation of multiple intracellular signal pathways involving NADPH oxidase, protein kinase C, and MAPKs, then resulting in NF-kappaB activity. NF-kappa B promotes the expression of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-alpha and a variety of atherosclerosis-related genes, including VCAM-1, tissue factor, VEGF, and RAGE. In addition, JAK-STAT-mediated and PI3K-Akt-dependent pathways are induced via RAGE, which in turn participate in cell proliferation and apoptosis respectively. Hypoxia-mediated induction of Egr-1 was also shown to require the AGE-RAGE interaction. The results of these signal transductions have been reported to be the possible mechanism that initates diabetic complications.",
BMGC_PW1866,BMG_PW6729,,"Cushing syndrome (CS) is a rare disorder resulting from prolonged exposure to excess glucocorticoids via exogenous and endogenous sources. The typical clinical features of CS are related to hypercortisolism and include accumulation of central fat, moon facies, neuromuscular weakness, osteoporosis or bone fractures, metabolic complications, and mood changes. Traditionally, endogenous CS is classified as adrenocorticotropic hormone (ACTH)-dependent (about 80%) or ACTH- independent (about 20%). Among ACTH-dependent forms, pituitary corticotroph adenoma (Cushing's disease) is most common. Most pituitary tumors are sporadic, resulting from monoclonal expansion of a single mutated cell. Recently recurrent activating somatic driver mutations in the ubiquitin-specific protease 8 gene (USP8) were identified in almost half of corticotroph adenoma. Germline mutations in MEN1 (encoding menin), AIP (encoding aryl-hydrocarbon receptor-interacting protein), PRKAR1A (encoding cAMP-dependent protein kinase type I alpha regulatory subunit) and CDKN1B (encoding cyclin-dependent kinase inhibitor 1B; also known as p27 Kip1) have been identified in familial forms of pituitary adenomas. However, the frequency of familial pituitary adenomas is less than 5% in patients with pituitary adenomas. Among ACTH-independent CS, adrenal adenoma is most common. Rare adrenal causes of CS include primary bilateral macronodular adrenal hyperplasia (BMAH) or primary pigmented nodular adrenocortical disease (PPNAD).",
BMGC_PW1867,BMG_PW6730,,"Growth hormone (GH) is a peptide hormone secreted from the anterior pituitary and plays a critical role in cell growth, development, and metabolism throughout the body. GH secretion occurs episodically and is primarily under the control of two hypothalamic neuroendocrine hormones: GH-releasing hormone (GHRH), which stimulates GH secretion, and somatostatin, which inhibits GH secretion. GHRH interacts with a G protein-coupled receptor (GHRHR) in somatotroph cells to activate the cAMP signaling pathway, which leads to increased GH mRNA transcription and release. Once released into the circulation, GH binds to cell-surface GHR in target tissues such as liver, muscle, bone, and adipose tissue. Binding leads to activation of JAK2 that in turn triggers an array of signaling cascade including Raf-MEK-ERK, PI3K-Akt, and STAT5. ERK, Akt, and STAT5 all promote growth via the synthesis and secretion of IGF-1.",
BMGC_PW1868,BMG_PW6731,,"Alcoholic liver disease (ALD) refers to the damages to the liver and its functions due to alcohol overconsumption. It ranges from simple steatosis to steatohepatitis, cirrhosis, and even hepatocellular carcinoma. Alcohol consumption promotes liver inflammation by increasing the translocation of gut-derived endotoxins to the portal circulation and activating Kupffer cells to produce TNF-alpha through the LPS/Toll like receptor (TLR) 4 pathways. TNF-alpha induces hepatocellular damage. When alcohol intake is chronic and heavy, steatosis is caused via generation of acetaldehyde, reactive oxygen species (ROS) and ER stress. ROS inhibits key hepatic transcriptional regulators such as AMP-activated kinase (AMPK) and peroxisome proliferator-activated receptor alpha (PPAR-alpha), which are responsible for fatty acid oxidation and export via ACC and CPT-1. The blockade of AMPK also leads to overexpression of SREBP-1, resulting in an increase of de novo lipogenesis. Moreover, excessive intracellular ROS production induced by ethanol and its metabolite have a critical role in ethanol-induced apoptosis, which may be the critical process in the exacerbation of ALD. It is inferred that the apoptotic signal derived from ROS that was produced by NOX, is mainly transduced through the JNK and p38 MAPK pathways.",
BMGC_PW1869,BMG_PW6732,,"Sodium transport across the tight epithelia of Na+ reabsorbing tissues such as the distal part of the kidney nephron and colon is the major factor determining total-body Na+ levels, and thus, long-term blood pressure. Aldosterone plays a major role in sodium and potassium metabolism by binding to epithelial mineralocorticoid receptors (MR) in the renal collecting duct cells localized in the distal nephron, promoting sodium resorption and potassium excretion. Aldosterone enters a target cell and binds MR, which translocates into the nucleus and regulates gene transcription. Activation of MR leads to increased expression of Sgk-1, which phosphorylates Nedd4-2, an ubiquitin-ligase which targets ENAC to proteosomal degradation. Phosphorylated Nedd4-2 dissociates from ENAC, increasing its apical membrane abundance. Activation of MR also leads to increased expression of Na+/K+-ATPase, thus causing a net increase in sodium uptake from the renal filtrate. The specificity of MR for aldosterone is provided by 11beta-HSD2 by the rapid conversion of cortisol to cortisone in renal cortical collecting duct cells. Recently, besides genomic effects mediated by activated MR, rapid aldosterone actions that are independent of translation and transcription have been documented.",
BMGC_PW1870,BMG_PW6733,,"Calcium (Ca2+) is essential for numerous physiological functions including intracellular signalling processes, neuronal excitability, muscle contraction and bone formation. Therefore, its homeostasis is finely maintained through the coordination of intestinal absorption, renal reabsorption, and bone resorption. In kidney, the late part of the distal convoluted tubule (DCT) and the connecting tubule (CNT) are the site of active Ca2+ transport and precisely regulate Ca2+ reabsorption. Following Ca2+ entry through TRPV5, Ca2+ bound to calbindin-D28K diffuses to the basolateral side, where it is extruded into the blood compartment through NCX1 and to a lesser extent PMCA1b. In the urinary compartment, both klotho and tissue kallikrein (TK) increase the apical abundance of TRPV5. In the blood compartment, PTH, 1,25(OH)2D3 and estrogen increase the transcription and protein expression of the luminal Ca2+ channels, calbindins, and the extrusion systems.",
BMGC_PW1871,BMG_PW6734,,"One of the major tasks of the renal proximal tubule (PT) is to secrete acid into the tubule lumen, thereby reabsorbing approximately 80% of the filtered bicarbonate (HCO3(-)), as well as generating ""new HCO3(-)"" for regulating blood pH. In the tubular lumen, filtered HCO3(-) combines with H(+) in a reaction catalyzed by CA IV. The CO2 thus produced rapidly diffuses into the tubular cells and is combined with water to produce intracellular H(+) and HCO3(-), catalyzed by soluble cytoplasmic CA II. HCO3(-) is then cotransported with Na(+) into blood via the NBC-1. The intracellular H(+) produced by CA II is secreted into the tubular lumen predominantly via the NHE-3. The PT creates the ""new HCO3(-)"" by taking glutamine and metabolizing it to two molecules each of NH4(+) and HCO3(-). The NH4(+) is excreted into the tubular lumen, and the HCO3(-) , which is ""new HCO3(-) ,"" is returned to the blood, where it replaces the HCO3(-) lost earlier in the titration of nonvolatile acids.",
BMGC_PW1872,BMG_PW6735,,"One of the important roles of the collecting duct segment of the kidney nephron is acid secretion. As daily food intake loads acid into the body, urinary acid excretion is essential, and urine pH can drop as low as 4.5. The alpha-intercalated cell of collecting duct is the main responsible for hydrogen secretion into the urine. The carbon dioxide, which is generated in the cells and enters from the blood, is changed to carbonic acid. This carbonic acid is divided into hydrogen ion and bicarbonate ion. Intracellular CA II catalyses the formation of these ions. The hydrogen ion is secreted into the lumen by the luminal H(+)-ATPase. The bicarbonate ion is transported to the blood side by the anion exchanger type 1. Hydrogen ion in the lumen is trapped by urinary buffers. These include ammonium and phosphate.",
BMGC_PW1873,BMG_PW6736,,"Saliva has manifold functions in maintaining the integrity of the oral tissues, in protecting teeth from caries, in the tasting and ingestion of food, in speech and in the tolerance of tenures, for example. Salivary secretion occurs in response to stimulation by neurotransmitters released from autonomic nerve endings. There are two secretory pathways: protein exocytosis and fluid secretion. Sympathetic stimulation leads to the activation of adenylate cyclase and accumulation of intracellular cAMP. The elevation of cAMP causes the secretion of proteins such as amylase and mucin. In contrast, parasympathetic stimulation activates phospholipase C and causes the elevation of intracellular Ca2+, which leads to fluid secretion; that is, water and ion transport. Ca2+ also induces amylase secretion, but the amount is smaller than that induced by cAMP.",
BMGC_PW1874,BMG_PW6737,,"The pancreas performs both exocrine and endocrine functions. The exocrine pancreas consists of two parts, the acinar and duct cells. The primary functions of pancreatic acinar cells are to synthesize and secrete digestive enzymes. Stimulation of the cell by secretagogues such as acetylcholine (ACh) and cholecystokinin (CCK) causes the generation of an intracellular Ca2+ signal. This signal, in turn, triggers the fusion of the zymogen granules with the apical plasma membrane, leading to the polarised secretion of the enzymes. The major task of pancreatic duct cells is the secretion of fluid and bicarbonate ions (HCO3-), which neutralize the acidity of gastric contents that enter the duodenum. An increase in intracellular cAMP by secretin is one of the major signals of pancreatic HCO3- secretion. Activation of the CFTR Cl- channel and the CFTR-dependent Cl-/HCO3- exchange activities is responsible for cAMP-induced HCO3- secretion.",
BMGC_PW1875,BMG_PW6738,,"Dietary carbohydrate in humans and omnivorous animals is a major nutrient. The carbohydrates that we ingest vary from the lactose in milk to complex carbohydrates. These carbohydrates are digested to monosaccharides, mostly glucose, galactose and fructose, prior to absorption in the small intestine. Glucose and galactose are initially transported into the enterocyte by SGLT1 located in the apical brush border membrane and then exit through the basolateral membrane by either GLUT2 or exocytosis. In a new model of intestinal glucose absorption, transport by SGLT1 induces rapid insertion and activation of GLUT2 in the brush border membrane by a PKC betaII-dependent mechanism. Moreover, trafficking of apical GLUT2 is rapidly up-regulated by glucose and artificial sweeteners, which act through T1R2 + T1R3/alpha-gustducin to activate PLC-beta2 and PKC-beta II. Fructose is transported separately by the brush border GLUT5 and then released out of the enterocyte into the blood by GLUT2.",
BMGC_PW1876,BMG_PW6739,,"Protein is a dietary component essential for nutritional homeostasis in humans. Normally, ingested protein undergoes a complex series of degradative processes following the action of gastric, pancreatic and small intestinal enzymes. The result of this proteolytic activity is a mixture of amino acids and small peptides. Amino acids (AAs) are transported into the enterocyte (intestinal epithelial cell) by a variety of AA transporters that are specific for cationic (basic) AA, neutral AA, and anionic (acidic) AA. Small peptides are absorbed into enterocytes by the PEPT1 transporter. Inside enterocytes peptides are hydrolyzed, and the resulting amino acids are released together with those absorbed by AA transporters into blood via multiple, basolateral, AA transporters. Hydrolysis-resistant peptides, however, are transported out of the cells by a basolateral peptide transporter that has not been identified molecularly.",
BMGC_PW1877,BMG_PW6740,,"Fat is an important energy source from food. More than 95% of dietary fat is long-chain triacylglycerols (TAG), the remaining being phospholipids (4.5%) and sterols. In the small intestine lumen, dietary TAG is hydrolyzed to fatty acids (FA) and monoacylglycerols (MAG) by pancreatic lipase. These products are then emulsified with the help of phospholipids (PL) and bile acids (BA) present in bile to form micelles. Free FAs and MAGs are taken up by the enterocyte where they are rapidly resynthesized in endoplasmic reticulum (ER) to form TAG. PLs from the diet as well as bile - mainly LPA - too are absorbed by the enterocyte and are acylated to form phosphatidic acid (PA), which is also converted into TAG. Absorbed cholesterol (CL) is acylated to cholesterol esters (CE). Within the ER, TAG joins CE and apolipoprotein B (ApoB) to form chylomicrons that enter circulation through the lymph.",
BMGC_PW1878,BMG_PW6741,,"Bile is a vital secretion, essential for digestion and absorption of fats and fat-soluble vitamins in the small intestine. Moreover, bile is an important route of elimination for excess cholesterol and many waste product, bilirubin, drugs and toxic compounds. Bile secretion depends on the function of membrane transport systems in hepatocytes and cholangiocytes and on the structural and functional integrity of the biliary tree. The hepatocytes generate the so-called primary bile in their canaliculi. Cholangiocytes modify the canalicular bile by secretory and reabsorptive processes as bile passes through the bile ducts. The main solutes in bile are bile acids, which stimulate bile secretion osmotically, as well as facilitate the intestinal absorption of dietary lipids by their detergent properties. Bile acids are also important signalling molecules. Through the activation of nuclear receptors, they regulate their own synthesis and transport rates.",
BMGC_PW1879,BMG_PW6742,,"Vitamins are a diverse and chemically unrelated group of organic substances that share a common feature of being essential for normal health and well-being. They catalyze numerous biochemical reactions. Because humans and other mammals cannot synthesize these compounds (except for some synthesis of niacin), they must obtain them from exogenous sources via intestinal absorption. Vitamins are classified based on their solubility in water or fat. Most of the water-soluble vitamins are transported across the small intestinal membrane by carrier-mediated mechanisms, but vitamin B12, cobalamin, is transported by a receptor-mediated mechanism. Intestinal absorption of fat-soluble vitamins requires all of the processes needed for fat absorption. After digestion, these vitamins and the products of pancreatic hydrolysis of triglycerides (TG) are emulsified by bile salts to form mixed micelles which are taken up by intestinal enterocytes and incorporated into chylomicrons (CM). CM are then secreted into the lymphatic system, and finally moves into the plasma.",
BMGC_PW1880,BMG_PW6743,,"Minerals are one of the five fundamental groups of nutrients needed to sustain life. Of the minerals, calcium plays innumerable roles in our bodies, serving as a main component of bone as well as an intracellular messenger in muscle contraction/relaxation, neural networks, the immune system, and endocrine/exocrine cells. Iron, copper, and other metals are required for redox reactions (as cofactors) and for oxygen transport and binding (in hemoglobin and myoglobin). Many enzymes require specific metal atoms to complete their catalytic functions. Animal tissues need moderate quantities of some elements (Ca, P, K, Na, Mg, S, and Cl) and trace amounts of others (Mn, Fe, I, Co, Cr, Cu, Zn, and Se). The minerals are absorbed by either passive or active transport systems through the intestinal mucosa, often using specialized transport proteins, such as ferritin for Fe3+ and vitamin D-induced protein for calcium.",
BMGC_PW1881,BMG_PW6744,,"Cholesterol is an essential component of mammalian cell membranes as well as a precursor of bile acids, vitamin D and steroid hormones. Cholesterol homeostasis in humans is regulated by well-balanced mechanisms of intestinal uptake, endogenous synthesis, transport in lipoprotein particles, and biliary excretion. Its abnormal metabolism can lead to increased risk for various endocrine disorders and cardiovascular diseases.",
BMGC_PW1882,BMG_PW6745,,,
BMGC_PW1883,BMG_PW6746,,,
BMGC_PW1884,BMG_PW6747,,"Huntington disease (HD) is an autosomal-dominant neurodegenerative disorder that primarily affects medium spiny striatal neurons (MSN). The symptoms are choreiform, involuntary movements, personality changes and dementia. HD is caused by a CAG repeat expansion in the IT15 gene, which results in a long stretch of polyglutamine (polyQ) close to the amino-terminus of the HD protein huntingtin (Htt). Mutant Htt (mHtt) has effects both in the cytoplasm and in the nucleus. Full-length huntingtin is cleaved by proteases in the cytoplasm, leading to the formation of cytoplasmic and neuritic aggregates. mHtt also alters vesicular transport and recycling, causes cytosolic and mitochondrial Ca2+  overload, triggers endoplasmic reticulum stress through proteasomal dysfunction, and impairs autophagy function, increasing neuronal death susceptibility. N-terminal fragments containing the polyQ strech translocate to the nucleus where they impair transcription and induce neuronal death.",
BMGC_PW1885,BMG_PW6748,,"The autosomal dominant spinocerebellar ataxias (SCAs) are a group of progressive neurodegenerative diseases characterised by loss of balance and motor coordination due to the primary dysfunction of the cerebellum. Compelling evidence points to major aetiological roles for transcriptional dysregulation, protein aggregation and clearance, autophagy, the ubiquitin-proteasome system, alterations of calcium homeostasis, mitochondria defects, toxic RNA gain-of-function mechanisms and eventual cell death with apoptotic features of neurons during SCA disease progression.",
BMGC_PW1886,BMG_PW6749,,"Neurodegeneration is generally defined as progressive, irreversible loss of neurons, which may affect either the peripheral or central nervous system (CNS). Neurodegenerative diseases (NDs) include highly debilitating illnesses, such as Alzheimer (AD), Parkinson disease (PD), amyotrophic lateral sclerosis, Huntington disease, spinocerebellar ataxias, and prion diseases (PrD). The hallmark event, which is thought to be at the root of these diseases, is the progressive accumulation of misfolded protein aggregates. Major basic processes include abnormal protein dynamics due to deficiency of the ubiquitin-proteosome-autophagy system, oxidative stress and free radical formation, endoplasmic reticulum stress, mitochondrial dysfunction and (secondary) disruptions of axonal transport.",
BMGC_PW1887,BMG_PW6750,,"Amphetamine is a psychostimulant drug that exerts persistent addictive effects. Most addictive drugs increase extracellular concentrations of dopamine (DA) in nucleus accumbens (NAc) and medial prefrontal cortex (mPFC), projection areas of mesocorticolimbic DA neurons and key components of the ""brain reward circuit"". Amphetamine achieves this elevation in extracellular levels of DA by promoting efflux from synaptic terminals. Acute administration of amphetamine induces phosphorylation of cAMP response element-binding protein (CREB) and expression of a number of immediate early genes (IEGs), such as c-fos. The IEGs is likely to initiate downstream molecular events, which may have important roles in the induction and maintenance of addictive states. Chronic exposure to amphetamine induces a unique transcription factor delta FosB, which plays an essential role in long-term adaptive changes in the brain.",
BMGC_PW1888,BMG_PW6751,,"Many pathogenic bacteria can invade phagocytic and non-phagocytic cells and colonize them intracellularly, then become disseminated to other cells. Invasive bacteria induce their own uptake by non-phagocytic host cells (e.g. epithelial cells) using two mechanisms referred to as zipper model and trigger model. Listeria, Staphylococcus, Streptococcus, and Yersinia are examples of bacteria that enter using the zipper model. These bacteria express proteins on their surfaces that interact with cellular receptors, initiating signalling cascades that result in close apposition of the cellular membrane around the entering bacteria. Shigella and Salmonella are the examples of bacteria entering cells using the trigger model. These bacteria use type III secretion systems to inject protein effectors that interact with the actin cytoskeleton.",
BMGC_PW1889,BMG_PW6752,,"Two major virulence factors of H. pylori are the vacuolating cytotoxin (VacA) and the cag type-IV secretion system (T4SS) and its translocated effector protein, cytotoxin-associated antigen A (CagA).             VacA binds to lipid rafts and glycosylphosphatidylinositol-anchored proteins (GPI-APs) of the target cell membrane. After insertion into the plasma membrane, VacA channels are endocytosed and eventually reach late endosomal compartments, increasing their permeability to anions with enhancement of the electrogenic vacuolar ATPase (v-ATPase) proton pump. In the presence of weak bases, osmotically active acidotropic ions will accumulate in the endosomes. This leads to water influx and vesicle swelling, an essential step in vacuole formation. In addition, it is reported that the VacA cleavage product binds to the tyrosine phosphatase receptor zeta (Ptprz) on epithelial cells and the induced signaling leads to the phosphorylation of the G protein-coupled receptor kinase-interactor 1 (Git1) and induces ulcerogenesis in mice.             The other virulence factor cag T4SS mediates the translocation of the effector protein CagA, which is subsequently phosphorylated by a Src kinase. Phosphorylated CagA interacts with the protein tyrosine phosphatase SHP-2, thus stimulating its phosphatase activity. Activated SHP-2 is able to induce MAPK signalling through Ras/Raf-dependent and -independent mechanisms. Deregulation of this pathway by CagA may lead to abnormal proliferation and movement of gastric epithelial cells.",
BMGC_PW1890,BMG_PW6753,,"Pathogenic Yersinia injects virulent Yersinia outer proteins (Yops) into the host cell through a type three secretion system (T3SS) to express its pathogenicity. Through inactivation of small GTPases by YopT protease, YopE GTPase-activating protein, and YpkA/YopO sequestration of GDP-bound small GTPases, Yersinia prevents its uptake by phagocytic cells and disrupts the actin cytoskeleton. YopH phosphatase shuts down phagocytosis by dephosphorylating key host proteins as well as suppresses T cell activation. Yersinia induces macrophage pyroptosis via YopB/YopD activation of canonical and noncanonical inflammasomes and YopT/YopE-mediated activation of pyrin. These effects are counteracted by YopK and YopM. YopP/J is a member of an ubiquitin-like protein cysteine protease family and simultaneously targets signaling components of the MAPK and NF-kappaB signaling pathways following activation of Toll-like receptor4 to inhibit production of proinflammatory cytokines.",
BMGC_PW1891,BMG_PW6754,,"Leishmania is an intracellular protozoan parasite of macrophages that causes visceral, mucosal, and cutaneous diseases. The parasite is transmitted to humans by sandflies, where they survive and proliferate intracellularly by deactivating the macrophage. Successful infection of Leishmania is achieved by alteration of signaling events in the host cell, leading to enhanced production of the autoinhibitory molecules like TGF-beta and decreased induction of cytokines such as IL12 for protective immunity. Nitric oxide production is also inhibited. In addition, defective expression of major histocompatibility complex (MHC) genes silences subsequent T cell activation mediated by macrophages, resulting in abnormal immune responses.",
BMGC_PW1892,BMG_PW6755,,"Trypanosoma brucei, the parasite responsible for African trypanosomiasis (sleeping sickness), are spread by the tsetse fly in sub-Saharan Africa. The parasites are able to pass through the blood-brain barrier and cause neurological damage by inducing cytokines like TNF alpha, IFN gamma, and IL1. These cytokines and other metabolites such as nitric oxide and somnogenic prostaglandin D2 disturb circadian rhythms in patients with African trypanosomiasis.",
BMGC_PW1893,BMG_PW6756,,"Entamoeba histolytica, an extracellular protozoan parasite is a human pathogen that invades the intestinal epithelium. Infection occurs on ingestion of contaminated water and food. The pathogenesis of amoebiasis begins with parasite attachment and disruption of the intestinal mucus layer, followed by apoptosis of host epithelial cells. Intestinal tissue destruction causes severe dysentery and ulcerations in amoebic colitis. Several amoebic proteins such as lectins, cysteine proteineases, and amoebapores are associated with the invasion process. The parasite can cause extraintestinal infection like amoebic liver abscess by evading immune response.",
BMGC_PW1894,BMG_PW6757,,"Hepatitis B virus (HBV) is an enveloped virus and contains a partially double-stranded relaxed circular DNA (RC-DNA) genome. After entry into hepatocytes, HBV RC-DNA is transported to the nucleus and converted into a covalently closed circular molecule cccDNA. The cccDNA is the template for transcription of all viral RNAs including the pregenomic RNA (pgRNA), encoding for 7 viral proteins: large, middle, and small envelope proteins (LHBs, MHBs, and SHBs) that form the surface antigen (HBsAg), the core antigen (HBcAg), the e antigen (HBeAg), the HBV polymerase, and the regulatory protein X (HBx). The pgRNA interacts with the viral polymerase protein to initiate the encapsidation into the core particles. Through endoplasmic reticulum, the core particles finish assembling with the envelope proteins and are released. HBV infection leads to a wide spectrum of liver diseases raging from chronic hepatitis, cirrhosis to hepatocellular carcinoma. The mechanism of liver injury is still not clear. However, HBV proteins target host proteins, involved in a variety of functions, thus regulating transcription, cellular signaling cascades, proliferation, differentiation, and apoptosis.",
BMGC_PW1895,BMG_PW6758,,"Human cytomegalovirus (HCMV) is an enveloped, double-stranded DNA virus that is a member of beta-herpesvirus family. HCMV is best known for causing significant morbidity and mortality in immunocompromised populations. As with other herpesviruses, HCMV gB and gH/gL envelope glycoproteins are essential for virus entry. HCMV gB could activate the PDGFRA, and induce activation of the oncogenic PI3-K/AKT pathway. Though it is unlikely that HCMV by itself can act as an oncogenic factor, HCMV may have an oncomodulatory role, to catalyze an oncogenic process that has already been initiated. US28, one of the four HCMV-encoded vGPCRs (US27, US28, UL33 and UL78), also has a specific role in the oncomodulatory properties. In addition, HCMV has developed numerous mechanisms for manipulating the host immune system. The virally encoded US2, US3, US6 and US11 gene products all interfere with major histocompatibility complex (MHC) class I antigen presentation. HCMV encodes several immediate early (IE) antiapoptotic proteins (IE1, IE2, vMIA and vICA). These proteins might avoid immune clearance of infected tumor cells by cytotoxic lymphocytes and NK cells.",
BMGC_PW1896,BMG_PW6759,,"Human papillomavirus (HPV) is a non-enveloped, double-stranded DNA virus. HPV infect mucoal and cutaneous epithelium resulting in several types of pathologies, most notably, cervical cancer. All types of HPV share a common genomic structure and encode eight proteins: E1, E2, E4, E5, E6, and E7 (early) and L1 and L2 (late). It has been demonstrated that E1 and E2 are involved in viral transcription and replication. The functions of the E4 protein is not yet fully understood. E5, E6, and E7 act as oncoproteins. E5 inhibits the V-ATPase, prolonging EGFR signaling and thereby promoting cell proliferation. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways. Among these pathways, PI3K/Akt signalling cascade plays a very important role in HPV-induced carcinogenesis. The L1 and L2 proteins form icosahedral capsids for progeny virion generation.",
BMGC_PW1897,BMG_PW6760,,"Human T-cell leukemia virus type 1 (HTLV-1) is a pathogenic retrovirus that is associated with adult T-cell leukemia/lymphoma (ATL). It is also strongly implicated in non-neoplastic chronic inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Expression of Tax, a viral regulatory protein is critical to the pathogenesis. Tax is a transcriptional co-factor that interfere several signaling pathways related to anti-apoptosis or cell proliferation. The modulation of the signaling by Tax involve its binding to transcription factors like CREB/ATF, NF-kappa B, and SRF.",
BMGC_PW1898,BMG_PW6761,,"Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is the most recently identified human tumor virus, and is associated with the pathogenesis of Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and Multicentric Castleman's disease (MCD). Like all other herpesviruses, KSHV displays two modes of life cycle, latency and lytic replication, which are characterized by the patterns of viral gene expression. Genes expressed in latency (LANA, v-cyclin, v-FLIP, Kaposins A, B and C and viral miRNAs) are mainly thought to facilitate the establishment of life long latency in its host and survival against the host innate, and adaptive immune surveillance mechanisms. Among the viral proteins shown to be expressed during lytic replication are potent signaling molecules such as vGPCR, vIL6, vIRFs, vCCLs, K1 and K15, which have been implicated experimentally in the angiogenic and inflammatory phenotype observed in KS lesions. Several of these latent viral and lytic proteins are known to transform host cells, linking KSHV with the development of severe human malignancies.",
BMGC_PW1899,BMG_PW6762,,"Herpes simplex virus 1(HSV-1) is a common human pathogen, which initially infects orofacial mucosal surfaces. The virus replicates in epithelial cells at these sites, causing clinically overt disease characterized by vesicular lesions. HSV-1 then penetrates to the nervous system and establishes latency in sensory neurons. Throughout the lifetime of the host, HSV-1 may reactivate from its latent state and reinitiate a lytic infection cycle. HSV-1 has developed various mechanisms to escape its host innate immune responses and increased its capacity to replicate and to persist. ICP34.5, ICP0, ICP27, Us11 and Vhs (UL41) are the proteins involved in viral interference.",
BMGC_PW1900,BMG_PW6763,,"Epstein-Barr virus (EBV) is a gamma-herpes virus that widely infects human populations predominantly at an early age but remains mostly asymptomatic. EBV has been linked to a wide spectrum of human malignancies, including nasopharyngeal carcinoma and other hematologic cancers, like Hodgkin's lymphoma, Burkitt's lymphoma (BL), B-cell immunoblastic lymphoma in HIV patients, and posttransplant-associated lymphoproliferative diseases.  EBV has the unique ability to establish life-long latent infection in primary human B lymphocytes. During latent infection, EBV expresses a small subset of genes, including 6 nuclear antigens (EBNA-1, -2, -3A, -3B, -3C, and -LP), 3 latent membrane proteins (LMP-1, -2A, and -2B), 2 small noncoding RNAs (EBER-1 and 2). On the basis of these latent gene expression, three different latency patterns associated with the types of cancers are recognized.",
BMGC_PW1901,BMG_PW6764,,"Human immunodeficiency virus type 1 (HIV-1) , the causative agent of AIDS (acquired immunodeficiency syndrome), is a lentivirus belonging to the Retroviridae family. The primary cell surface receptor for HIV-1, the CD4 protein, and the co-receptor for HIV-1, either CCR5 or CXCR4, are found on macrophages and T lymphocytes. At the earliest step, sequential binding of virus envelope (Env) glycoprotein gp120 to CD4 and the co-receptor CCR5 or CXCR4 facilitates HIV-1 entry and has the potential to trigger critical signaling that may favor viral replication. At advanced stages of the disease, HIV-1 infection results in dramatic induction of T-cell (CD4+ T and CD8+ T cell) apoptosis both in infected and uninfected bystander T cells, a hallmark of HIV-1 pathogenesis. On the contrary, macrophages are resistant to the cytopathic effect of HIV-1 and produce virus for longer periods of time.",
BMGC_PW1902,BMG_PW6765,,"Coronavirus disease of 2019 (COVID-19) is a highly contagious respiratory infection that is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 infects alveolar epithelial cells [mainly alveolar epithelial type 2 (AEC2) cells] through the angiotensin-converting enzyme 2 (ACE2) receptor. Upon the occupancy of ACE2 by SARS-CoV-2, the increased serum level of free Angiotensin II (Ang II) due to a reduction of ACE2-mediated degradation promotes activation of the NF-kappa B pathway via Ang II type 1 receptor (AT1R), followed by  interleukin-6 (IL-6) production. SARS-CoV-2 also activates the innate immune system; macrophage stimulation triggers the overproduction of pro-inflammatory cytokines, including IL-6, and the ""cytokine storm"", which results in systemic inflammatory response syndrome and multiple organ failure. The combined effects of complement activation, dysregulated neutrophilia, endothelial injury, and hypercoagulability appear to be intertwined to drive the severe features of COVID-19.",
BMGC_PW1903,BMG_PW6766,,,
BMGC_PW1904,BMG_PW6767,,"In tumor cells, genes encoding transcription factors (TFs) are often amplified, deleted, rearranged via chromosomal translocation and inversion, or subjected to point mutations that result in a gain- or loss-of- function. In hematopoietic cancers and solid tumors, the translocations and inversions increase or deregulate transcription of the oncogene. Recurrent chromosome translocations generate novel fusion oncoproteins, which are common in myeloid cancers and soft-tissue sarcomas. The fusion proteins have aberrant transcriptional function compared to their wild-type counterparts. These fusion transcription factors alter expression of target genes, and thereby result in a variety of altered cellular properties that contribute to the tumourigenic process.",
BMGC_PW1905,BMG_PW6768,,"There is a strong association between viruses and the development of human malignancies. We now know that at least six human viruses, Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), human papilloma virus (HPV), human T-cell lymphotropic virus (HTLV-1) and Kaposi's associated sarcoma virus (KSHV) contribute to 10-15% of the cancers worldwide. Via expression of many potent oncoproteins, these tumor viruses promote an aberrant cell-proliferation via modulating cellular cell-signaling pathways and escape from cellular defense system such as blocking apoptosis. Human tumor virus oncoproteins can also disrupt pathways that are necessary for the maintenance of the integrity of host cellular genome. Viruses that encode such activities can contribute to initiation as well as progression of human cancers.",
BMGC_PW1906,BMG_PW6769,,"It has been estimated that exposure to environmental chemical carcinogens may contribute significantly to the causation of a sizable fraction, perhaps a majority, of human cancers. Human carcinogens act through a variety of genotoxic and non-genotoxic mechanisms. Genotoxic carcinogens can attack biological macromolecules such as DNA and RNA either directly or indirectly through metabolism, resulting in the formation of adducts with these macromolecules. If DNA adducts escape cellular repair mechanisms and persist, they may lead to miscoding, resulting in permanent mutations. Mutations cause an undefined number of cell changes, translated into aberrant protein expression and in changes in cell cycle control.",
BMGC_PW1907,BMG_PW6770,,"Many proteoglycans (PGs) in the tumor microenvironment have been shown to be key macromolecules that contribute to biology of various types of cancer including proliferation, adhesion, angiogenesis and metastasis, affecting tumor progress. The four main types of proteoglycans include hyaluronan (HA), which does not occur as a PG but in free form, heparan sulfate proteoglycans (HSPGs), chondroitin sulfate proteoglycans (CSPGs), dematan sulfate proteoglycans (DSPG) and keratan sulfate proteoglycans (KSPGs) [BR:00535]. Among these proteoglycans such as HA, acting with CD44, promotes tumor cell growth and migration, whereas other proteoglycans such as syndecans (-1~-4), glypican (-1, -3) and perlecan may interact with growth factors, cytokines, morphogens and enzymes through HS chains [BR:00536], also leading to tumor growth and invasion. In contrast, some of the small leucine-rich proteolgycans, such as decorin and lumican, can function as tumor repressors, and modulate the signaling pathways by the interaction of their core proteins and multiple receptors.",
BMGC_PW1908,BMG_PW6771,,"MicroRNA (miRNA) is a cluster of small non-encoding RNA molecules of 21 - 23 nucleotides in length, which controls gene expression post-transcriptionally either via the degradation of target mRNAs or the inhibition of protein translation. Using high-throughput profiling, dysregulation of miRNAs has been widely observed in different stages of cancer. The upregulation (overexpression) of specific miRNAs could lead to the repression of tumor suppressor gene expression, and conversely the downregulation of specific miRNAs could result in an increase of oncogene expression; both these situations induce subsequent malignant effects on cell proliferation, differentiation, and apoptosis that lead to tumor growth and progress. The miRNA signatures of cancer observed in various studies differ significantly. These inconsistencies occur due to the differences in the study populations and methodologies used. This pathway map shows the summarized results from various studies in 9 cancers, each of which is presented in a review article.",
BMGC_PW1909,BMG_PW6772,,"Carcinogenesis is a multistage process that consists of initiation, promotion, and progression stages. Chemicals or environmental factors may act at any of these stages to induce and/or enhance the carcinogenic process. Based on their mode-of-action, carcinogens can be classified as genotoxic or non-genotoxic. Genotoxic agent begins their action at the deoxyribonucleic acid (DNA) level, causing DNA damage through several mechanisms. Non-genotoxic carcinogens are chemicals that cause the development of tumors through multiple non-genotoxic events and epigenetic alterations without direct interaction with DNA. One non-genotoxic mechanism involves receptor activation. Biological mechanisms involving receptor activation fall into two broad categories: (i) those that involve cell surface receptors and some intracellular receptors that activate signal transduction pathways, resulting in biological responses, including gene transcription, and (ii) those that involve intracellular receptors that translocate into the nucleus and act as transcription factors regulating gene expression. Both classes of receptors can be involved in mechanisms of carcinogenesis.",
BMGC_PW1910,BMG_PW6773,,"It is well established that cancer is a multi-step process which involves initiation, promotion and progression. Chemical carcinogens can alter any of these processes to induce their carcinogenic effects. In the majority of instances, chemical carcinogens, directly or after xenobiotic metabolism, induce DNA damage and act in a 'genotoxic' manner. There is, however, a group of carcinogens that induce cancer via nongenotoxic mechanisms. The biochemical modes of action for nongenotoxic carcinogens are diverse, one example of which is induction of oxidative stress. Trace metals and organic xenobiotics are typical classes of environmental pollutants with prooxidant effects. Trace metals generate reactive oxygen species (ROS) depending on their ability to lose electrons and catalyze Haber Weiss and Fenton reactions. ROS are also generated due to induction of various cytochrome P450 isoenzymes during detoxification of chemical carcinogens. Increased ROS generation often has been linked to DNA damage that can lead to mutations and may, therefore, play an important role in the initiation and progression of multistage carcinogenesis. Besides causing DNA damage, ROS further induce multiple intracellular signaling pathways, notably NF-kappa B, JNK/SAPK/p38, as well as Erk/MAPK. These signaling routes can lead to transcriptional induction of target genes that could promote proliferation or confer apoptosis resistance to exposed cells.",
BMGC_PW1911,BMG_PW6774,,"Renal cell cancer (RCC) accounts for ~3% of human malignancies and its incidence appears to be rising. Although most cases of RCC seem to occur sporadically, an inherited predisposition to renal cancer accounts for 1-4% of cases. RCC is not a single disease, it has several morphological subtypes. Conventional RCC (clear cell RCC) accounts for ~80% of cases, followed by papillary RCC (10-15%), chromophobe RCC (5%), and collecting duct RCC (<1%). Genes potentially involved in sporadic neoplasms of each particular type are VHL, MET, BHD, and FH respectively. In the absence of VHL, hypoxia-inducible factor alpha (HIF-alpha) accumulates, leading to production of several growth factors, including vascular endothelial growth factor and platelet-derived growth factor. Activated MET mediates a number of biological effects including motility, invasion of extracellular matrix, cellular transformation, prevention of apoptosis and metastasis formation. Loss of functional FH leads to accumulation of fumarate in the cell, triggering inhibition of HPH and preventing targeted pVHL-mediated degradation of HIF-alpha. BHD mutations cause the Birt-Hogg-Dube syndrome and its associated chromophobe, hybrid oncocytic, and conventional (clear cell) RCC.",
BMGC_PW1912,BMG_PW6775,,"Gliomas are the most common of the primary brain tumors and account for more than 40% of all central nervous system neoplasms. Gliomas include tumours that are composed predominantly of astrocytes (astrocytomas), oligodendrocytes (oligodendrogliomas), mixtures of various glial cells (for example,oligoastrocytomas) and ependymal cells (ependymomas). The most malignant form of infiltrating astrocytoma - glioblastoma multiforme (GBM) - is one of the most aggressive human cancers. GBM may develop de novo (primary glioblastoma) or by progression from low-grade or anaplastic astrocytoma (secondary glioblastoma). Primary glioblastomas develop in older patients and typically show genetic alterations (EGFR amplification, p16/INK4a deletion, and PTEN mutations) at frequencies of 24-34%. Secondary glioblastomas develop in younger patients and frequently show overexpression of PDGF and CDK4 as well as p53 mutations (65%) and loss of Rb playing major roles in such transformations. Loss of PTEN has been implicated in both pathways, although it is much more common in the pathogenesis of primary GBM.",
BMGC_PW1913,BMG_PW6776,,"Cancer of the skin is the most common cancer in Caucasians and basal cell carcinomas (BCC) account for 90% of all skin cancers. The vast majority of BCC cases are sporadic, though there is a rare familial syndrome basal cell nevus syndrome (BCNS, or Gorlin syndrome) that predisposes to development of BCC. In addition, there is strong epidemiological and genetic evidence that demonstrates UV exposure as a risk factor of prime importance. The development of basal cell carcinoma is associated with constitutive activation of sonic hedgehog signaling. The mutations in SMOH, PTCH1, and SHH in BCCs result in continuous activation of target genes. At a cellular level, sonic hedgehog signaling promotes cell proliferation. Mutations in TP53 are also found with high frequency (>50%) in sporadic BCC.",
BMGC_PW1914,BMG_PW6777,,"Melanoma is a form of skin cancer that has a poor prognosis and which is on the rise in Western populations. Melanoma arises from the malignant transformation of pigment-producing cells, melanocytes. The only known environmental risk factor is exposure to ultraviolet (UV) light and in people with fair skin the risk is greatly increased. Melanoma pathogenesis is also driven by genetic factors. Oncogenic NRAS mutations activate both effector pathways Raf-MEK-ERK and PI3K-Akt. The Raf-MEK-ERK pathway may also be activated via mutations in the BRAF gene. The PI3K-Akt pathway may be activated through loss or mutation of the inhibitory tumor suppressor gene PTEN. These mutations arise early during melanoma pathogenesis and are preserved throughout tumor progression. Melanoma development has been shown to be strongly associated with inactivation of the p16INK4a/cyclin dependent kinases 4 and 6/retinoblastoma protein (p16INK4a/CDK4,6/pRb) and p14ARF/human double minute 2/p53 (p14ARF/HMD2/p53) tumor suppressor pathways. MITF and TP53 are implicated in further melanoma progression.",
BMGC_PW1915,BMG_PW6778,,"Breast cancer is the leading cause of cancer death among women worldwide. The vast majority of breast cancers are carcinomas that originate from cells lining the milk-forming ducts of the mammary gland. The molecular subtypes of breast cancer, which are based on the presence or absence of hormone receptors (estrogen and progesterone subtypes) and human epidermal growth factor receptor-2 (HER2), include: hormone receptor positive and HER2 negative (luminal A subtype), hormone receptor positive and HER2 positive (luminal B subtype), hormone receptor negative and HER2 positive (HER2 positive), and hormone receptor negative and HER2 negative (basal-like or triple-negative breast cancers (TNBCs)). Hormone receptor positive breast cancers are largely driven by the estrogen/ER pathway. In HER2 positive breast tumours, HER2 activates the PI3K/AKT and the RAS/RAF/MAPK pathways, and stimulate cell growth, survival and differentiation. In patients suffering from TNBC, the deregulation of various signalling pathways (Notch and Wnt/beta-catenin), EGFR protein have been confirmed. In the case of breast cancer only 8% of all cancers are hereditary, a phenomenon linked to genetic changes in BRCA1 or BRCA2. Somatic mutations in only three genes (TP53, PIK3CA and GATA3) occurred at >10% incidence across all breast cancers.",
BMGC_PW1916,BMG_PW6779,,"Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and one of the rare human neoplasms etiologically linked to viral factors. It has been shown that, after HBV/HCV infection and alcohol or aflatoxin B1 exposure, genetic and epigenetic changes occur. The recurrent mutated genes were found to be highly enriched in multiple key driver signaling processes, including telomere maintenance, TP53, cell cycle regulation, the Wnt/beta-catenin pathway (CTNNB1 and AXIN1), the phosphatidylinositol-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway. Recent studies using whole-exome sequencing have revealed recurrent mutations in new driver genes involved in the chromatin remodelling (ARID1A and ARID2) and the oxidative stress (NFE2L2) pathways.",
BMGC_PW1917,BMG_PW6780,,"Gastric cancer (GC) is one of the world's most common cancers. According to Lauren's histological classification gastric cancer is divided into two distinct histological groups - the intestinal and diffuse types. Several genetic changes have been identified in intestinal-type GC. The intestinal metaplasia is characterized by mutations in p53 gene, reduced expression of retinoic acid receptor beta (RAR-beta) and hTERT expression. Gastric adenomas furthermore display mutations in the APC gene, reduced p27 expression and cyclin E amplification. In addition, amplification and overexpression of c-ErbB2, reduced TGF-beta receptor type I (TGFBRI) expression and complete loss of p27 expression are commonly observed in more advanced GC. The main molecular changes observed in diffuse-type GCs include loss of E-cadherin function by mutations in CDH1 and amplification of MET and FGFR2F.",
BMGC_PW1918,BMG_PW6781,,"Malignant transformation of cells requires specific adaptations of cellular metabolism to support growth and survival. In the early twentieth century, Otto Warburg established that there are fundamental differences in the central metabolic pathways operating in malignant tissue. He showed that cancer cells consume a large amount of glucose, maintain high rate of glycolysis and convert a majority of glucose into lactic acid even under normal oxygen concentrations (Warburg's Effects). More recently, it has been recognized that the 'Warburg effect' encompasses a similarly increased utilization of glutamine. From the intermediate molecules provided by enhanced glycolysis and glutaminolysis, cancer cells synthesize most of the macromolecules required for the duplication of their biomass and genome. These cancer-specific alterations represent a major consequence of genetic mutations and the ensuing changes of signalling pathways in cancer cells. Three transcription factors, c-MYC, HIF-1 and p53, are key regulators and coordinate regulation of cancer metabolism in different ways, and many other oncogenes and tumor suppressor genes cluster along the signaling pathways that regulate c-MYC, HIF-1 and p53.",
BMGC_PW1919,BMG_PW6782,,"Abnormal choline metabolism is emerging as a metabolic hallmark that is associated with oncogenesis and tumour progression. Following transformation, oncogenic signalling via pathways such as the RAS and PI3K-AKT pathways, and transcription factors associated with oncogenesis such as hypoxia-inducible factor 1 (HIF1) mediate overexpression and activation of choline cycle enzymes, which causes increased levels of choline-containing precursors and breakdown products of membrane phospholipids. These products of choline phospholipid metabolism, such as phosphocholine (PCho), diacylglycerol (DAG) and phosphatidic acid, may function as second messengers that are essential for the mitogenic activity of growth factors, particularly in the activation of the ras-raf-1-MAPK cascade and protein kinase C pathway.",
BMGC_PW1920,BMG_PW6783,,"Programmed cell death 1 (PD1) and its ligand (PDL1) are key regulatory physiological immune checkpoints that maintain self-tolerance in the organism by regulating the degree of activation of T and B  cells amongst other immune cell types. In solid tumors, the PD-1/PD-L1 inhibitory pathway can be (mis-)used to silence the immune system by increasing the expression of PD-L1 on the tumor cell surface. Up-regulation of PD-L1 is caused by activation of pro-survival pathways MAPK and PI3K/Akt as well as transcriptional factors HIF-1, STAT3 and NF-kappa B. The MAPK and PI3K signalling pathways are activated by gene mutations and growth factors. PD-L1 on tumor cells may then engage the PD-1 receptors resulting in suppression of T-cell mediated immune response. Therapeutic antibodies blocking the PD-1/PD-L1 pathway by targeting PD-L1 or PD-1 are highly effective in rescuing T cell anti-tumor effector functions.",
BMGC_PW1921,BMG_PW6784,,"Asthma is a complex syndrome with many clinical phenotypes in both adults and children. Its major characteristics include a variable degree of airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Inhaled allergens encounter antigen presenting cells (APC) that line the airway. Upon recognition of the antigen and activation by APC, naive T cells differentiate into TH2 cells. Activated TH2 stimulate the formation of IgE by B cells. IgE molecules bind to IgE receptors located on mast cells. The crosslinking of mast-cell-bound IgE by allergens leads to the release of biologically active mediators (histamine, leukotrienes) by means of degranulation and, so, to the immediate symptoms of allergy. Mast cells also release chemotactic factors that contribute to the recruitment of inflammatory cells, particularly eosinophils, whose proliferation and differentiation from bone marrow progenitors is promoted by IL-5. The activation of eosinophils leads to release of toxic granules and oxygen free radicals that lead to tissue damage and promote the development of chronic inflammation.",
BMGC_PW1922,BMG_PW6785,,"The classification of autoimmune throid disease (AITD) includes Hashimoto's thyroiditis (HT) or chronic autoimmune thyroiditis and its variants, Graves' disease (GD) and autoimmune atrophic thyroiditis or primary myxedema. HT is characterized by the presence of goitre, thyroid autoantibodies against thyroid peroxidase (TPO) and thyroglobulin (Tg) in serum and varying degrees of thyroid dysfunction. During HT, self-reactive CD4+ T lymphocytes (Th) recruit B cells and CD8+ T cells (CTL) into the thyroid. Disease progression leads to the death of thyroid cells and hypothyroidism. Both autoantibodies and thyroid-specific cytotoxic T lymphocytes (CTLs) have been proposed to be responsible for autoimmune thyrocyte depletion. In GD, the TSH-R is the most important autoantigen. Antibodies directed against it mimic the effects of the hormone on thyroid cells, TSH, stimulating autonomous production of thyroxine and triiodothyronine and causing hyperthyroidism. The presence of TSH-R-blocking antibodies that bind the TSH receptor in a similar fashion to the antibodies in patients with Grave's disease but that block rather than activate the receptor explains some cases of atrophic hypothyroidism.",
BMGC_PW1923,BMG_PW6786,,"Inflammatory bowel disease (IBD), which includes Crohn disease (CD) and ulcerative colitis (UC), is characterized by chronic inflammation of the gastrointestinal tract due to environmental and genetic factors, infectious microbes, and the dysregulated immune system. Although many environmental factors (for example, geographic locations, smoking, etc.) affect the development of IBD, the most crucial might be the luminal (external) environment of the epithelial cells. There are pathogens that are found in increasing frequency in IBD. The microbial components such as flagellin, peptidoglycan, and lipopolysaccharide are recognized by receptors such as toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD) proteins, and also by antigen-presenting cells (APCs) in genetically susceptible host. The TLR recognition triggers the activation of NF-kappaB, leading to an inflammatory response. APC-expressed gene NOD2 has been associated with Crohn disease. In case of mutations of NOD2, negative regulation of IL-12 production is reduced with the stimulation of muramyl dipeptide (MDP), leading to CD. In addition, the APC mediates the differentiation of naive T cells into effector T cells (Th1, Th17, Th2) and natural killer T (NKT) cells. Th1 and Th17 cells produce high levels of IFN-gamma and IL-17, -22, respectively, both of which promote CD. In contrast, Th2 cells produce IL-4, -5, -10, which together with IL-13 from NKT induce UC.",
BMGC_PW1924,BMG_PW6787,,"Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterised by the production of IgG autoantibodies that are specific for self-antigens, such as DNA, nuclear proteins and certain cytoplasmic components, in association with a diverse array of clinical manifestations. The primary pathological findings in patients with SLE are those of inflammation, vasculitis, immune complex deposition, and vasculopathy. Immune complexes comprising autoantibody and self-antigen is deposited particulary in the renal glomeruli and mediate a systemic inflammatory response by activating complement or via Fc{gamma}R-mediated neutrophil and macrophage activation. Activation of complement (C5) leads to injury both through formation of the membrane attack complex (C5b-9) or by generation of the anaphylatoxin and cell activator C5a. Neutrophils and macrophages cause tissue injury by the release of oxidants and proteases.",
BMGC_PW1925,BMG_PW6788,,"Rheumatoid arthritis (RA) is a chronic autoimmune joint disease where persistent inflammation affects bone remodeling leading to progressive bone destruction. In RA, abnormal activation of the immune system elevates pro-inflammatory cytokines and chemokines levels, which can promote synovial angiogenesis and leukocyte infiltration. The synovium forms a hyperplastic pannus with infiltrated macrophage-like and fibroblast-like synoviocytes and invades joints by secreting proteinases and inducing osteoclast differentiation.",
BMGC_PW1926,BMG_PW6789,,"Graft-versus-host disease (GVHD) is a lethal complication of allogeneic hematopoietic stem cell transplantation (HSCT) where immunocompetent donor T cells attack the genetically disparate host cells. GVHD pathophysiology can be summerized in a three-step process. Step 1 involves the development of an inflammatory milieu resulting from damage in the host tissues induced by the preparative chemotherapy or radiotherapy regimen. Damaged tissues secrete inflammatory cytokines, including interleukin 1 (IL-1), and tumor necrosis factor (TNF-alpha ). During step 2, antigen-presenting cells (APCs) trigger the activation of donor-derived T cells, which induce further T-cell expansion, induce cytotoxic T lymphocytes (CTL) and natural killer (NK) cells responses and prime additional mononuclear phagocytes to produce TNF-alpha and IL-1. Also, nitric oxide (NO) is produced by activated macrophages, and it may contribute to the tissue damage seen during step 3. During step 3, the effector phase, activated CTL and NK cells mediate cytotoxicity against target host cells through Fas-Fas ligand interactions and perforin-granzyme B.",
BMGC_PW1927,BMG_PW6790,,"Primary immunodeficiencies (PIs) are a heterogeneous group of disorders, which affect cellular and humoral immunity or non-specific host defense mechanisms mediated by complement proteins, and cells such as phagocytes and natural killer (NK) cells. These disorders of the immune system cause increased susceptibility to infection, autoimmune disease, and malignancy. Most of PIs are due to genetic defects that affect cell maturation or function at different levels during hematopoiesis. Disruption of the cellular immunity is observed in patients with defects in T cells or both T and B cells. These cellular immunodeficiencies comprise 20% of all PIs. Disorders of humoral immunity affect B-cell differentiation and antibody production. They account for 70% of all PIs.",
BMGC_PW1928,BMG_PW6791,,"Diabetic cardiomyopathy has been defined as left ventricular dysfunction that occurs among patients with diabetes mellitus independent of a recognized cause such as coronary artery disease or hypertension. The pathogenesis of diabetic cardiomyopathy broadly involves hyperglycemia, increased circulating fatty acids, and insulin resistance contributing to reactive oxygen species (ROS) generation, mitochondrial dysfunction, impaired calcium metabolism, Renin-Angiotensin System (RAS) activation, and altered substrate metabolism. These effects result in cardiac fibrosis, hypertrophy, cardiomyocyte death, contractile dysfunction, endothelial cell damage and eventually heart failure. In the process of cardiac fibrosis, cardiac fibroblasts are the final effector cell.",
BMGC_PW1929,BMG_PW6792,,"Atherosclerosis is a chronic inflammatory disease marked by a narrowing of the arteries from lipid-rich plaques present within the walls of arterial blood vessels. It represents the root cause of the majority of cardiovascular diseases (CVDs) and their complications, including conditions such as coronary artery disease, myocardial infarction and stroke.  An elevated level of low density lipoprotein (LDL) cholesterol constitutes a major risk factor for genesis of atherosclerosis. LDL can accumulate within the blood vessel wall and undergo modification by oxidation. Oxidized LDL (oxLDL) leads to endothelial dysfunction leading to expression of adhesion molecules and recruitment of monocyte in subendothelial space. The monocytes proliferate, differentiate into macrophages, and take up the lipoproteins, forming cholesterol-engorged ""foam cells."" With the time, the foam cells die, leaving a 'necrotic core' of crystalline cholesterol and cell debris. Smooth muscle cells proliferate and migrate into the region, laying down a protective cap over the lesion. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), which mediates the recognition and internalization of oxLDL, is involved in all of these events critical in the pathogenesis of atherosclerosis.",
BMGC_PW1930,BMG_PW6793,,"Shear stress represents the frictional force that the flow of blood exerts at the endothelial surface of the vessel wall and plays a central role in vascular biology and contributes to the progress of atherosclerosis. Sustained laminar flow with high shear stress upregulates expressions of endothelial cell (EC) genes and proteins that are protective against atherosclerosis. The key shear stress-induced transcription factors that govern the expression of these genes are Kruppel-like factor 2 (KLF2) and nuclear factor erythroid 2-like 2 (Nrf2). On the other hand, disturbed flow with associated reciprocating, low shear stress generally upregulates the EC genes and proteins that promote oxidative and inflammatory states in the artery wall, resulting in atherogenesis. Important transcriptional events that reflect this condition of ECs in disturbed flow include the activation of activator protein 1 (AP-1) and nuclear factor kappaB (NF-kappaB).",