Disease relevance of GAPDH

• In addition, we have found that GAPDH mRNA expression is markedly increased in human lung cancer tissues [1].
• This evidence supports a functional role for GAPDH in neurodegenerative diseases [2].
• Glyceraldehyd-3-phospate dehydrogenase (GAPDH) and NPY gene expression in neuroblastomas of 50 patients were measured in parallel by competitive quantitative and TaqMan real-time RT-PCR [3].
• The purified autoantibodies to GAPDH from lupus serum showed both nuclear speckled and cytoplasmic staining patterns in immunofluorescence on Hep-2 cells [4].
• Nuclear localization of GAPDH was observed in another thyroid cancer cell line, KTC2, which is also sensitive to TRAIL, but not in those TRAIL insensitive cell lines: ARO, KTC1, and KTC3 [5].

Psychiatry related information on GAPDH

• In the nuclear fraction, deficits of 27% and 33% in GAPDH function were observed in Alzheimer's and Huntington's disease, respectively [2].
• Previous in vitro studies suggest an interaction between GAPDH and the beta-amyloid precursor protein (beta-APP), a protein directly involved in Alzheimer's disease (AD) [6].
• MAIN OUTCOME MEASURE(S): The frequency of p53 loss and/or gain based on quantitative differences for copy numbers of p53 located on chromosome (17p) and GAPDH on a control locus (chromosome 12p) [7].
• A new method of calculation, based on a direct fitting of the protein fluorescence intensity observed upon coenzyme binding (H.-P. Lutz, unpublished results), is used to study the negative cooperative behavior of glyceraldehyde-3-phosphate dehydrogenase from sturgeon muscle [8].

High impact information on GAPDH

• Surprisingly, p38 represents a nuclear form of glyceraldehyde-3-phosphate dehydrogenase, and binding to Oct-1, as well as OCA-S function, is stimulated by NAD(+) but inhibited by NADH [9].
• S phase activation of the histone H2B promoter by OCA-S, a coactivator complex that contains GAPDH as a key component [9].
• Comparison of amino acid sequences shows that the chloroplast GAPDHs are related to GAPDHs found in thermophilic bacteria, while the cytosolic GAPDH is related to the GAPDH found in mesophilic prokaryotes [10].
• We report nucleotide sequences of cDNAs for the nuclear genes encoding chloroplast (GapA and GapB) and cytosolic (GapC) glyceraldehyde-3-phosphate dehydrogenases (GAPDH) from N. tabacum [10].
• This alteration of the redox state of the erythrocyte leads to inhibition of glycolysis at the level of glyceraldehyde 3-phosphate dehydrogenase and rapid decline in cellular energy (ATP) stores [11].

Chemical compound and disease context of GAPDH

• We have shown that a Mr 37,000 protein whose expression is strongly enhanced in human lung cancer tissues is the subunit of glyceraldehyde-3-phosphate (GAPDH, EC 1.2.1.12) [1].
• The mixed cell foci, neoplastic nodules and carcinomas which emerged at later stages were characterized by a progressive shift away from glycogen metabolism towards glycolysis and the pentose phosphate pathway. as indicated by an increase in glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase activities [12].
• Using breast cancer cells, we demonstrate that glycolaldehyde inactivates glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and Cu,Zn superoxide dismutase, suppresses cell growth, and induces apoptosis [13].
• This novel NES does not contain multiple leucine residues unlike other CRM1-interacting NES, is conserved in GAPDH from multiple species, and has sequence similarities to the export signal found in feline immunodeficiency virus Rev protein [14].
• Western blot analysis of nuclear extracts from a panel of human lymphoblastic leukemia cell lines revealed markedly different basal levels of GAPDH in nuclei, which was significantly related to thiopurine sensitivity (p = 0.001) [15].

Biological context of GAPDH

• Depletion of GAPDH or Siah1 by RNA interference diminishes nuclear translocation of mHtt [16].
• We have isolated a GAPDH complementary DNA from human lung cancer cells and deduced the complete amino acid sequence of the encoded protein [1].
• The ratio between oxidized and reduced glulathione and the oxidation-dependent inactivation of glyceraldehyde-3phosphate dehydrogenase (GAPDH) are considered independent markers of cellular reactive oxygen species homeostasis and redox state [17].
• Thus, the RNA binding specificity of GAPDH as well as its localization within the cell merit its strong consideration as a protein important in the regulation of ARE-dependent mRNA turnover and translation in addition to its well described role in glycolysis [18].
• The direct demonstration of ARE-specific binding protein activity localized to the NAD(+)-binding region of GAPDH supports the general concept that enzymes containing this domain may exhibit specific RNA binding activity and play additional roles in nucleic acid metabolism [18].

Anatomical context of GAPDH

• Finally, cytoplasmic GAPDH was found in the polysomal fraction of T lymphocytes [18].
• The elution of GAPDH from the membranes prevents the stimulation by the substrates, but not by exogenous ATP [19].
• In animals and other heterotrophic eukaryotes, both enzymes are localized in the cytosol; in photosynthetic eukaryotes, GAPDH and TPI exist as isoenzymes that function in the glycolytic pathway of the cytosol and in the Calvin cycle of chloroplasts [20].
• Here, we show that diatoms--photosynthetic protists that acquired their plastids through secondary symbiotic engulfment of a eukaryotic rhodophyte--possess an additional isoenzyme each of both GAPDH and TPI [20].
• Surprisingly, these new forms are expressed as an TPI-GAPDH fusion protein which is imported into mitochondria prior to its assembly into a tetrameric bifunctional enzyme complex [20].

Associations of GAPDH with chemical compounds

• While provocative, these findings do not address the selective neuronal loss in each of these disorders in light of the wide expression patterns of GAPDH and the respective polyglutamine containing proteins [21].
• Further data demonstrated that the nuclear localization of GAPDH is regulated by ceramide in a cell cycle-dependent manner parallel with the inhibition of its telomere binding activity in response to ceramide [22].
• Patch-clamp electrophysiology showed that GAPDH regulates K(ATP)-channel activity irrespective of high intracellular ATP, by producing 1,3-bisphosphoglycerate, a K(ATP)-channel opener [23].
• Hexokinase plus glucose (agents that promote breakdown of ATP) prevent stimulation of Na transport by exogenous ATP but not by the substrates for GAPDH and PGK [19].
• No effect on the expression of the apurinic endonuclease hAPE or the house-keeping gene GAPDH was observed at any of the concentrations of sodium dichromate investigated [24].
• GAPDH enhanced the transcriptional activity of AR(T875A) activated by an antagonist such as hydroxyflutamide or cyproterone acetate [25].
• Because GAPDH has four cysteine residues, including the active site Cys(149), we prepared the cysteine-substituted mutants C149S, C153S, C244A, C281S, and C149S/C281S to identify which is responsible for disulfide-bonded aggregation [26].

Physical interactions of GAPDH

• Supershift analyses show that Oct-1 binds directly to the T-13,910 variant, and we suggest that GAPDH is co-purified due to interactions with Oct-1 [27].
• Spinocerebellar ataxia type-1 and spinobulbar muscular atrophy gene products interact with glyceraldehyde-3-phosphate dehydrogenase [21].
• Competition studies suggested that cytoplasmic GAPDH binds the AU-rich elements (AREs) of lymphokine mRNA 3'-untranslated regions with higher affinity than tRNA [18].
• The purified protein as well as commercial GAPDH binds tightly to TNF-alpha ribozyme compared to a variety of other ribozymes and RNAs [28].
• GAPDH binds specifically to proteins implicated in the pathogenesis of a variety of neurodegenerative disorders including the beta-amyloid precursor protein and the huntingtin protein [2].
• The GAPDH variants C152G and C156G retain the ability to interact with but are unable to reactivate APE1, implicating these cysteines in catalyzing the reduction of APE1 [29].

Enzymatic interactions of GAPDH

• This assay employs phosphoglycerate kinase to catalyse the formation 1,3- bisphosphoglycerate which is then used to oxidise NADH in the presence of glyceraldehyde 3-phosphate dehydrogenase [30].
• The non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase catalyses the irreversible reaction of glyceraldehyde-3-phosphate to 3-phosphoglycerate by the reduction of NADP to NADPH [31].

Regulatory relationships of GAPDH

• The treatment of cells with reduced human Trx stimulated the synthesis of GAPDH mRNA [32].
• In some cases, FLT3 was expressed at levels equivalent to GAPDH in the absence of genomic amplification [33].
• Both CP12 and CTE seem to regulate different photosynthetic GAPDH isoforms according to a common and ancient molecular mechanism [34].
• CLDN1 mRNA was downregulated by 12-fold in the sample (tumour) group as compared with the control group using GAPDH as the reference gene [35].
• RESULTS: AM/-actin and AM/GAPDH mRNA ratios were significantly lower in placental villi in preeclampsia than in controls (P<0.05) as were CGRP/-actin and CGRP/GAPDH mRNA ratios in chorionic plates (P<0.05) [36].

Other interactions of GAPDH

• Huntingtin and DRPLA proteins selectively interact with the enzyme GAPDH [37].
• Triosephosphate isomerase- and glyceraldehyde-3-phosphate dehydrogenase-reactive autoantibodies in the cerebrospinal fluid of patients with multiple sclerosis [38].
• Similarly, the transfection of cells with an expression plasmid for Trx increased GAPDH mRNA synthesis [32].
• However, an analysis of the ability of various prototypical ribozymes to inhibit the expression of interleukin-2 suggests that the addition of a sequence having a high affinity for GAPDH improves the efficacy of ribozymes in the cells [28].
• In parallel experiments, ketoconazole affected neither the expression of GR, the expression of glyceraldehyde-3-phosphate dehydrogenase, nor the inducible expression of CYP1A1 and 1A2 [39].

Analytical, diagnostic and therapeutic context of GAPDH

• The oxidized fraction was 0.13+/-0.02 of total GAPDH in control cultures and increased by 56+/-5.3% after treatment with 1,25(OH)2D3, which did not affect the total reduced enzyme activity [17].
• The association of nuclear GAPDH with telomeres in interphase nuclei was also demonstrated by co-fluorescence in situ hybridization and chromatin immunoprecipitation analysis [22].
• Steady state RNA levels were monitored by Northern blot analysis using a plasmid (pChug 20.1) which contained the 1.3 kb GAPDH/UDG cDNA [40].
• Immunoprecipitation/western blotting analysis with anti-Kir6.2, anti-SUR2A and anti-GAPDH antibodies showed that GAPDH is a part of the sarcolemmal K(ATP)-channel protein complex in vivo [23].
• Real-time quantitative RT-PCR reactions using conventional, non-RNA-specific primers on saliva samples yielded PCR products for 36B4, beta-actin, and GAPDH; DNase-treated saliva samples did not yield a PCR product, and the "no-RT" and "+RT" conditions yielded similar amounts of PCR product [41].

References