Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays an important role in glycolysis and gluconeogenesis []by reversibly catalysing the oxidation and phosphorylation of D-glyceraldehyde-3-phosphate to 1,3-diphospho-glycerate. The enzyme exists as a tetramer of identical subunits, each containing 2 conserved functional domains: an NAD-binding domain, and a highly conserved catalytic domain []. The enzyme has been found to bind to actin and tropomyosin, and may thus have a role in cytoskeleton assembly. Alternatively, the cytoskeleton may provide a framework for precise positioning of the glycolytic enzymes, thus permitting efficient passage of metabolites from enzyme to enzyme [].GAPDH displays diverse non-glycolytic functions as well, its role depending upon its subcellular location. For instance, the translocation of GAPDH to the nucleus acts as a signalling mechanism for programmed cell death, or apoptosis []. The accumulation of GAPDH within the nucleus is involved in the induction of apoptosis, where GAPDH functions in the activation of transcription. The presence of GAPDH is associated with the synthesis of pro-apoptotic proteins like BAX, c-JUN and GAPDH itself.GAPDH has been implicated in certain neurological diseases: GAPDH is able to bind to the gene products from neurodegenerative disorders such as Huntington's disease, Alzheimer's disease, Parkinson's disease and Machado-Joseph disease through stretches encoded by their CAG repeats. Abnormal neuronal apoptosis is associated with these diseases. Propargylamines such as deprenyl increase neuronal survival by interfering with apoptosis signalling pathways via their binding to GAPDH, which decreases the synthesis of pro-apoptotic proteins [].This entry represents the N-terminal domain which is a Rossmann NAD(P) binding fold.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays an important role in glycolysis and gluconeogenesis []by reversibly catalysing the oxidation and phosphorylation of D-glyceraldehyde-3-phosphate to 1,3-diphospho-glycerate. The enzyme exists as a tetramer of identical subunits, each containing 2 conserved functional domains: an NAD-binding domain, and a highly conserved catalytic domain []. The enzyme has been found to bind to actin and tropomyosin, and may thus have a role in cytoskeleton assembly. Alternatively, the cytoskeleton may provide a framework for precise positioning of the glycolytic enzymes, thus permitting efficient passage of metabolites from enzyme to enzyme [].GAPDH displays diverse non-glycolytic functions as well, its role depending upon its subcellular location. For instance, the translocation of GAPDH to the nucleus acts as a signalling mechanism for programmed cell death, or apoptosis []. The accumulation of GAPDH within the nucleus is involved in the induction of apoptosis, where GAPDH functions in the activation of transcription. The presence of GAPDH is associated with the synthesis of pro-apoptotic proteins like BAX, c-JUN and GAPDH itself.GAPDH has been implicated in certain neurological diseases: GAPDH is able to bind to the gene products from neurodegenerative disorders such as Huntington's disease, Alzheimer's disease, Parkinson's disease and Machado-Joseph disease through stretches encoded by their CAG repeats. Abnormal neuronal apoptosis is associated with these diseases. Propargylamines such as deprenyl increase neuronal survival by interfering with apoptosis signalling pathways via their binding to GAPDH, which decreases the synthesis of pro-apoptotic proteins [].This entry represents the C-terminal domain which is a mixed alpha/antiparallel beta fold.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays an important role in glycolysis and gluconeogenesis []by reversibly catalysing the oxidation and phosphorylation of D-glyceraldehyde-3-phosphate to 1,3-diphospho-glycerate. The enzyme exists as a tetramer of identical subunits, each containing 2 conserved functional domains: an NAD-binding domain, and a highly conserved catalytic domain []. The enzyme has been found to bind to actin and tropomyosin, and may thus have a role in cytoskeleton assembly. Alternatively, the cytoskeleton may provide a framework for precise positioning of the glycolytic enzymes, thus permitting efficient passage of metabolites from enzyme to enzyme [].GAPDH displays diverse non-glycolytic functions as well, its role depending upon its subcellular location. For instance, the translocation of GAPDH to the nucleus acts as a signalling mechanism for programmed cell death, or apoptosis []. The accumulation of GAPDH within the nucleus is involved in the induction of apoptosis, where GAPDH functions in the activation of transcription. The presence of GAPDH is associated with the synthesis of pro-apoptotic proteins like BAX, c-JUN and GAPDH itself.GAPDH has been implicated in certain neurological diseases: GAPDH is able to bind to the gene products from neurodegenerative disorders such as Huntington's disease, Alzheimer's disease, Parkinson's disease and Machado-Joseph disease through stretches encoded by their CAG repeats. Abnormal neuronal apoptosis is associated with these diseases. Propargylamines such as deprenyl increase neuronal survival by interfering with apoptosis signalling pathways via their binding to GAPDH, which decreases the synthesis of pro-apoptotic proteins [].This entry contains a small clade of dehydrogenases in gamma-proteobacteria which utilise NAD+ to oxidize erythrose-4-phosphate (E4P) to 4-phospho-erythronate, a precursor for the de novo synthesis of pyridoxine via 4-hydroxythreonine and D-1-deoxyxylulose []. This enzyme activity appears to have evolved from glyceraldehyde-3-phosphate dehydrogenase, whose substrate differs only in the lack of one carbon relative to E4P. It is possible that some of the GAPDH enzymes may prove to be bifunctional in certain species.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays an important role in glycolysis and gluconeogenesis []by reversibly catalysing the oxidation and phosphorylation of D-glyceraldehyde-3-phosphate to 1,3-diphospho-glycerate. The enzyme exists as a tetramer of identical subunits, each containing 2 conserved functional domains: an NAD-binding domain, and a highly conserved catalytic domain []. The enzyme has been found to bind to actin and tropomyosin, and may thus have a role in cytoskeleton assembly. Alternatively, the cytoskeleton may provide a framework for precise positioning of the glycolytic enzymes, thus permitting efficient passage of metabolites from enzyme to enzyme [].GAPDH displays diverse non-glycolytic functions as well, its role depending upon its subcellular location. For instance, the translocation of GAPDH to the nucleus acts as a signalling mechanism for programmed cell death, or apoptosis []. The accumulation of GAPDH within the nucleus is involved in the induction of apoptosis, where GAPDH functions in the activation of transcription. The presence of GAPDH is associated with the synthesis of pro-apoptotic proteins like BAX, c-JUN and GAPDH itself.GAPDH has been implicated in certain neurological diseases: GAPDH is able to bind to the gene products from neurodegenerative disorders such as Huntington's disease, Alzheimer's disease, Parkinson's disease and Machado-Joseph disease through stretches encoded by their CAG repeats. Abnormal neuronal apoptosis is associated with these diseases. Propargylamines such as deprenyl increase neuronal survival by interfering with apoptosis signalling pathways via their binding to GAPDH, which decreases the synthesis of pro-apoptotic proteins [].A cysteine in the middle of the molecule is involved in forming a covalent phosphoglycerol thioester intermediate. The sequence around this cysteine is totally conserved in eubacterial and eukaryotic GAPDHs and is also present, albeit in a variant form, in the otherwise highly divergent archaebacterial GAPDH []. The pattern in this entry represents the active site.
This entry includes CP12, a chloroplast protein that regulates the Calvin cycle responsible for CO2 assimilation []. Oxidized CP12 forms a supramolecular complex with two key Calvin cycle enzymes, GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and PRK (phosphoribulokinase), down-regulating their activity. It also interacts with other enzymes such as aldolase and malate dehydrogenase []. This entry also includes proteins from Cyanobacteria (blue-green algae).
This entry contains a small clade of dehydrogenases in gamma-proteobacteria which utilise NAD+ to oxidize erythrose-4-phosphate (E4P) to 4-phospho-erythronate, a precursor for the de novo synthesis of pyridoxine via 4-hydroxythreonine and D-1-deoxyxylulose []. This enzyme activity appears to have evolved from glyceraldehyde-3-phosphate dehydrogenase, whose substrate differs only in the lack of one carbon relative to E4P. It is possible that some of the GAPDH enzymes may prove to be bifunctional in certain species.
This entry represents an uncharacterised domain found in calvin cycle protein CP12 and other proteins. This domain is sometimes found in association cystathionine-beta-synthase domains.CP12 is a chloroplast protein that regulates the Calvin cycle responsible for CO2 assimilation []. Oxidized CP12 forms a supramolecular complex with two key Calvin cycle enzymes, GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and PRK (phosphoribulokinase), down-regulating their activity. It also interacts with other enzymes such as aldolase and malate dehydrogenase [].
This group of sequences represent glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the enzyme responsible for the interconversion of 1,3-diphosphoglycerate and glyceraldehyde-3-phosphate, a central step in glycolysis and gluconeogenesis. Forms exist which utilise NAD (), NADP () or either (). In some species, NAD- and NADP- utilising forms exist, generally being responsible for reactions in the anabolic and catabolic directions respectively []. An additional form of gap gene is found in gamma proteobacteria and is responsible for the conversion of erythrose-4-phosphate (E4P) to 4-phospho-erythronate in the biosynthesis of pyridoxine []. This pathway of pyridoxine biosynthesis appears to be limited, however, to a relatively small number of bacterial species although it is prevalent among the gamma-proteobacteria []. This enzyme is described by . These two groups of sequences exhibit a close evolutionary relationship. There exists the possibility that some forms of GAPDH may be bifunctional and act on E4P in species which make pyridoxine and via hydroxythreonine and lack a separate E4PDH enzyme (for instance, the GAPDH from Bacillus stearothermophilus has been shown to possess a limited E4PD activity as well as a robust GAPDH activity []).
