The cDNAs for glyceraldehyde-3-phosphate dehydrogenase (GAPDH; EC 1.2.1.12) were cloned from cerebellar neurons undergoing age-induced apoptosis and/or healthy cells. COS-7 cells were transfected with the isolated GAPDH cDNA
s using to the Lipofectamine method. Assessment of cell death in this paradigm was performed by monitoring the co-transfected luciferase activities and the characterization of cell death was examined by the DNA fragmentation assay and Hoechst dye nuclear staining. These observations show that over-expression of GAPDH occurring from both cDNAs robustly induces apoptotic death in the transfected COS-7 cell cultures. Confocal-immunocytochemical studies using this GAPDH-specific monoclonal antibody revealed that nuclear translocation of overexpressed GAPDH is a primary apoptotic event. Our results directly demonstrate that over-expressed GAPDH functions as a 'killing protein' in apoptosis.
Qvit N, etal., J Biol Chem. 2016 Jun 24;291(26):13608-21. doi: 10.1074/jbc.M115.711630. Epub 2016 Apr 27.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an important glycolytic enzyme, has a non-catalytic (thus a non-canonical) role in inducing mitochondrial elimination under oxidative stress. We recently demonstrated that phosphorylation of GAPDH
ght:700;'>GAPDH by d protein kinase C (dPKC) inhibits this GAPDH-dependent mitochondrial elimination. dPKC phosphorylation of GAPDH correlates with increased cell injury following oxidative stress, suggesting that inhibiting GAPDH phosphorylation should decrease cell injury. Using rational design, we identified pseudo-GAPDH (¿GAPDH) peptide, an inhibitor of dPKC-mediated GAPDH phosphorylation that does not inhibit the phosphorylation of other dPKC substrates. Unexpectedly, ¿GAPDH decreased mitochondrial elimination and increased cardiac damage in an animal model of heart attack. Either treatment with ¿GAPDH or direct phosphorylation of GAPDH by dPKC decreased GAPDH tetramerization, which corresponded to reduced GAPDH glycolytic activity in vitro and ex vivo Taken together, our study identified the potential mechanism by which oxidative stress inhibits the protective GAPDH-mediated elimination of damaged mitochondria. Our study also identified a pharmacological tool, ¿GAPDH peptide, with interesting properties. ¿GAPDH peptide is an inhibitor of the interaction between dPKC and GAPDH and of the resulting phosphorylation of GAPDH by dPKC. ¿GAPDH peptide is also an inhibitor of GAPDH oligomerization and thus an inhibitor of GAPDH glycolytic activity. Finally, we found that ¿GAPDH peptide is an inhibitor of the elimination of damaged mitochondria. We discuss how this unique property of increasing cell damage following oxidative stress suggests a potential use for ¿GAPDH peptide-based therapy.
Seidler NW, Adv Exp Med Biol. 2013;985:1-36. doi: 10.1007/978-94-007-4716-6_1.
The GAPDH gene is highly conserved with a promoter that contains several types of regulatory elements, perhaps even in a distal intron. Curiously, the transcription start site shows some ambiguity and there are codon-sharing exons at alternate exon junctions. Wh
ile there is only one functional gene for GAPDH in humans, the genome is littered with pseudogenes, representing a trove of researchable content. Tissue-specific expression speaks to the glycolytic function of GAPDH; thus, it's not surprising to see expression increased in cancer cells. Modulation of protein levels becomes an opportunity for intervention. The abundance of GAPDH in the cell provides the rationale (albeit, tenuous) for its use as a loading control. The single paralogous GAPDHS, which is the spermatogenic form of the protein, provides a curious study in cell-type specificity and perhaps intervention (i.e. contraception). And it is no wonder that great biochemists were kept busy for decades unveiling the nuances of GAPDH enzymology. While the active site of the enzyme is well-characterized and the catalytic mechanism is well-described, the role of inter-subunit interactions in catalysis still offers some mysteries, particularly with regards to other emerging enzymatic properties. The GAPDH protein exhibits an intrinsic asymmetry of the subunits, which also may speak to its functional diversity.
S-nitrosylation of proteins by nitric oxide is a major mode of signalling in cells. S-nitrosylation can mediate the regulation of a range of proteins, including prominent nuclear proteins, such as HDAC2 (ref. 2) and PARP1 (ref. 3). The high reactivity of the nitric oxide group with protein thiols,
but the selective nature of nitrosylation within the cell, implies the existence of targeting mechanisms. Specificity of nitric oxide signalling is often achieved by the binding of nitric oxide synthase (NOS) to target proteins, either directly or through scaffolding proteins such as PSD-95 (ref. 5) and CAPON. As the three principal isoforms of NOS--neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS)--are primarily non-nuclear, the mechanisms by which nuclear proteins are selectively nitrosylated have been elusive. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is physiologically nitrosylated at its Cys 150 residue. Nitrosylated GAPDH (SNO-GAPDH) binds to Siah1, which possesses a nuclear localization signal, and is transported to the nucleus. Here, we show that SNO-GAPDH physiologically transnitrosylates nuclear proteins, including the deacetylating enzyme sirtuin-1 (SIRT1), histone deacetylase-2 (HDAC2) and DNA-activated protein kinase (DNA-PK). Our findings reveal a novel mechanism for targeted nitrosylation of nuclear proteins and suggest that protein-protein transfer of nitric oxide groups may be a general mechanism in cellular signal transduction.
Allen M, etal., Neurobiol Aging. 2012 Jan;33(1):203.e25-33. doi: 10.1016/j.neurobiolaging.2010.08.002. Epub 2010 Sep 23.
Glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) and its paralogs were implicated in late-onset Alzheimer's disease (LOAD), although the strength and direction of association have not been consistent. We genotyped 3 previously reported single nucleotide pol
ymorphisms (SNPs; rs3741916-GAPDH 5' UTR, rs2029721-pGAPD, and rs4806173-GAPDHS) in 3 case-control series (2112 cases and 3808 controls). Rs3741916 showed the strongest LOAD association (p = 0.003). The minor allele of rs3741916 showed a protective effect in our combined series (odds ratio [OR] = 0.87%, 95% confidence interval [CI] = 0.79-0.96). This is consistent with results from the 2 published follow-up studies and in opposite direction of the original report. Meta-analysis of the published series with ours suggests presence of heterogeneity (Breslow-Day p < 0.0001). Meta-analysis of only the follow-up series including ours revealed a significant protective effect for the minor allele of rs3741916 (OR = 0.85%, 95% CI = 0.76-0.96, p = 0.009). Our results support the presence of LOAD variants and heterogeneity at the GAPDH locus. The most promising rs3741916 variant is unlikely to be functional given opposing effects in different series. Identification of functional variant(s) in this region likely awaits deep sequencing.
Sen N, etal., Neuron. 2009 Jul 16;63(1):81-91. doi: 10.1016/j.neuron.2009.05.024.
We recently reported a cell death cascade whereby cellular stressors activate nitric oxide formation leading to S-nitrosylation of GAPDH that binds to Siah and translocates to the nucleus. The nuclear GAPDH/Siah complex augm
ents p300/CBP-associated acetylation of nuclear proteins, including p53, which mediate cell death. We report a 52 kDa cytosolic protein, GOSPEL, which physiologically binds GAPDH, in competition with Siah, retaining GAPDH in the cytosol and preventing its nuclear translocation. GOSPEL is neuroprotective, as its overexpression prevents NMDA-glutamate excitotoxicity while its depletion enhances death in primary neuron cultures. S-nitrosylation of GOSPEL at cysteine 47 enhances GAPDH-GOSPEL binding and the neuroprotective actions of GOSPEL. In intact mice, virally delivered GOSPEL selectively diminishes NMDA neurotoxicity. Thus, GOSPEL may physiologically regulate the viability of neurons and other cells.
Liang S, etal., Int J Biol Macromol. 2015 Nov;81:375-86. doi: 10.1016/j.ijbiomac.2015.08.028. Epub 2015 Aug 13.
BACKGROUND: Acute hypoxia and reoxygenation injury, as a common environmental stress condition, is a basic condition of most pathophysiological processes. It has been approve that autophagy and oxidant stress could contribute to acute hypoxia and reoxygenation injury. This study is aimed to examine
the effect of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) silence on cell injury with acute hypoxia and reoxygenation injury by autophagy and antioxidant stress pathway. METHODS: GAPDH expression was silenced by siRNA in H9C2 cardiomyoblasts with acute hypoxia and reoxygenation injury. Autophagy was detected by western blot for autophagy proteins and monodansylcadaverine (MDC) staining for acidic substances. Pro-apoptosis protein and flow cytometry were used to assess cell apoptosis and death and intracellular adenosine triphosphate (ATP) relative concentration was measured. Oxidant stress was assessed by measuring 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA), thiobarbituric acid reactive substances (TBARS), glutathione (GSH) and super oxide dismutase (SOD). RESULTS: In this study, GAPDH-silence enhanced autophagy in H9C2 cells with acute hypoxia and reoxygenation injury, decreased oxidant stress and increased antioxidant pathways; and reduced cell apoptosis and death. However, GAPDH-silence had no significant effect on cell energy. CONCLUSION: GAPDH pre-silence by siRNA reduces H9C2 cell death occurring via autophagy and anti-oxidative stress pathway in acute hypoxia and reoxygenation injury. This study enriches the understanding of GAPDH pathophysiology role, and provides potential new therapeutic targets for cardiac disease states characterized by oxidative stress.
Mitochondrial dysfunction is implicated in multiple neurodegenerative diseases. In order to maintain a healthy population of functional mitochondria in cells, defective mitochondria must be properly eliminated by lysosomal machinery in a process referred to as mitophagy. Here, we uncover a new molec
ular mechanism underlying mitophagy driven by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) under the pathological condition of Huntington's disease (HD) caused by expansion of polyglutamine repeats. Expression of expanded polyglutamine tracts catalytically inactivates GAPDH (iGAPDH), which triggers its selective association with damaged mitochondria in several cell culture models of HD. Through this mechanism, iGAPDH serves as a signaling molecule to induce direct engulfment of damaged mitochondria into lysosomes (micro-mitophagy). However, abnormal interaction of mitochondrial GAPDH with long polyglutamine tracts stalled GAPDH-mediated mitophagy, leading to accumulation of damaged mitochondria, and increased cell death. We further demonstrated that overexpression of inactive GAPDH rescues this blunted process and enhances mitochondrial function and cell survival, indicating a role for GAPDH-driven mitophagy in the pathology of HD.
El Kadmiri N, etal., J Clin Neurosci. 2017 Jun;40:24-26. doi: 10.1016/j.jocn.2016.12.007. Epub 2017 Jan 10.
INTRODUCTION: Neuroproteomics studies have showed the high affinity interactions between GAPDH - ß-amyloid in Alzheimer disease. The aim of our study is to complete our previous studies by assessing the mechanism responsible of decreased expression of
GAPDH protein in the blood of Moroccan AD cases probably due to an alteration at the transcriptional level or at the post translational level. METHODS: The mRNA expression of GAPDH was assessed by quantitative real time PCR in AD cases and healthy controls. RESULTS: Our result revealed a significant difference of mRNA expression level of GAPDH in AD cases as compared to healthy controls (P<0.05). CONCLUSION: This data is consistent with several studies by showing the direct involvement of GAPDH in amyloid aggregation by undergoing several modifications, which influence its chemical structure and its biological activity.
The aim of the present study was to investigate whether diabetic embryopathy may be associated with the inhibition of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) resulting from an excess of reactive oxygen species (ROS) in the embryo. Recent demonstrations
of enhanced ROS production in mitochondria of bovine aortic endothelial cells exposed to high glucose have supported the idea that the pathogenesis of diabetic complications may involve ROS-induced GAPDH inhibition. We investigated whether a teratogenic diabetic environment also inhibits embryonic GAPDH activity and alters GAPDH gene expression and whether antioxidants diminish such GAPDH inhibition. In addition, we determined whether the inhibition of GAPDH with iodoacetate induces dysmorphogenesis, analogous to that caused by high glucose concentration, and whether antioxidants modulated the putative teratogenic effect of such direct GAPDH inhibition. We found that embryos from diabetic rats and embryos cultured in high glucose concentrations showed decreased activity of GAPDH (by 40-60%) and severe dysmorphogenesis on gestational days 10.5 and 11.5. GAPDH mRNA was decreased in embryos of diabetic rats compared to control embryos. Supplementing the high-glucose culture with the antioxidant N-acetylcysteine (NAC) increased GAPDH activity and diminished embryonic dysmorphogenesis. Embryos cultured with iodoacetate showed both decreased GAPDH activity and dysmorphogenesis; supplementing the culture with NAC increased both parameters toward normal values. In conclusion, dysmorphogenesis caused by maternal diabetes is correlated with ROS-induced inhibition of GAPDH in embryos, which could indicate that inhibition of GAPDH plays a causal role in diabetic embryopathy.
Chang C, etal., Mol Cell. 2015 Dec 17;60(6):930-40. doi: 10.1016/j.molcel.2015.10.037. Epub 2015 Nov 25.
Eukaryotes initiate autophagy to cope with the lack of external nutrients, which requires the activation of the nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase Sirtuin 1 (Sirt1). However, the mechanisms underlying the starvation-induced Sirt1 activation for autophagy initiation rem
ain unclear. Here, we demonstrate that glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a conventional glycolytic enzyme, is a critical mediator of AMP-activated protein kinase (AMPK)-driven Sirt1 activation. Under glucose starvation, but not amino acid starvation, cytoplasmic GAPDH is phosphorylated on Ser122 by activated AMPK. This causes GAPDH to redistribute into the nucleus. Inside the nucleus, GAPDH interacts directly with Sirt1, displacing Sirt1's repressor and causing Sirt1 to become activated. Preventing this shift of GAPDH abolishes Sirt1 activation and autophagy, while enhancing it, through overexpression of nuclear-localized GAPDH, increases Sirt1 activation and autophagy. GAPDH is thus a pivotal and central regulator of autophagy under glucose deficiency, undergoing AMPK-dependent phosphorylation and nuclear translocation to activate Sirt1 deacetylase activity.
Liu YJ, etal., BMC Genomics. 2009 Oct 16;10:480. doi: 10.1186/1471-2164-10-480.
BACKGROUND: Pseudogenes provide a record of the molecular evolution of genes. As glycolysis is such a highly conserved and fundamental metabolic pathway, the pseudogenes of glycolytic enzymes comprise a standardized genomic measuring stick and an ideal platform for studying molecular evolution. One
of the glycolytic enzymes, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), has already been noted to have one of the largest numbers of associated pseudogenes, among all proteins. RESULTS: We assembled the first comprehensive catalog of the processed and duplicated pseudogenes of glycolytic enzymes in many vertebrate model-organism genomes, including human, chimpanzee, mouse, rat, chicken, zebrafish, pufferfish, fruitfly, and worm (available at http://pseudogene.org/glycolysis/). We found that glycolytic pseudogenes are predominantly processed, i.e. retrotransposed from the mRNA of their parent genes. Although each glycolytic enzyme plays a unique role, GAPDH has by far the most pseudogenes, perhaps reflecting its large number of non-glycolytic functions or its possession of a particularly retrotranspositionally active sub-sequence. Furthermore, the number of GAPDH pseudogenes varies significantly among the genomes we studied: none in zebrafish, pufferfish, fruitfly, and worm, 1 in chicken, 50 in chimpanzee, 62 in human, 331 in mouse, and 364 in rat. Next, we developed a simple method of identifying conserved syntenic blocks (consistently applicable to the wide range of organisms in the study) by using orthologous genes as anchors delimiting a conserved block between a pair of genomes. This approach showed that few glycolytic pseudogenes are shared between primate and rodent lineages. Finally, by estimating pseudogene ages using Kimura's two-parameter model of nucleotide substitution, we found evidence for bursts of retrotranspositional activity approximately 42, 36, and 26 million years ago in the human, mouse, and rat lineages, respectively. CONCLUSION: Overall, we performed a consistent analysis of one group of pseudogenes across multiple genomes, finding evidence that most of them were created within the last 50 million years, subsequent to the divergence of rodent and primate lineages.
Mi Q, etal., Ann Clin Lab Sci. 2018 Jul;48(4):460-468.
OBJECTIVE: Excitotoxic neuronal death induced by epilepsy is associated with α-amino-3-hydroxyl-5-methylisoxazole-4-propionate acid (AMPA) receptors. The GluR2 subunit of AMPA receptors (AMPARs) may bind with glyceraldehyde-3-phosphate dehydrogenase (GAPDH
APDH). The GluR2/GAPDH complex co-internalizes upon stimulation of AMPARs, which might be involved in the development of epilepsy. In this research, we hypothesized that disruption of the GluR2/GAPDH interaction with an interfering peptide would protect against neuronal damage in vivo. METHODS: Rat models of epilepsy were induced by pilocarpine hydrochloride. TAT-GluR2NT1-3-2 peptide was synthesized to block interaction between GluR2 and GAPDH. Fluoro-Jade B and TUNEL staining were used to detect degeneration and apoptosis of neurons after interference by the peptide. Co-immunoprecipitation assay and western-blot was performed to confirm that the peptide disturbed interactions between GluR2 and GAPDH. RESULTS: The time of epileptic seizure was found to be delayed after peptide interference. It was concluded that administration of an interfering peptide is able to significantly reduce degeneration and apoptosis of neurons. The GluR2/GAPDH interaction and GAPDH nuclear expression were upregulated in the hippocampus of rats subjected to pilocarpine-induced seizures. CONCLUSION: Disruption of the GluR2/GAPDH interaction by administration of an interfering peptide protects against seizure-induced neuronal damage that is dose dependent. Thus, the GluR2/GAPDH interaction may be a novel therapeutic target for development of treatment for epilepsy.
Glyceraldehyde-3-phosphate dehydrogenase, is one of the most investigated housekeeping genes and widely used as an internal control in analysis of gene expression levels. The present study was designed to assess whether GAPDH is associated with cancer cell growt
h and progression and, therefore may not be a good internal control in cancer research. Our results from clinical tissue studies showed that the levels of GAPDH protein were significantly up-regulated in lung squamous cell carcinoma tissues, compared with the adjacent normal lung tissues, and this was confirmed by western blotting and immunohistochemistry. GAPDH knockdown by siRNA resulted in significant reductions in proliferation, migration, and invasion of lung squamous carcinoma cells in vitro. In a nude mouse cancer xenograft model, GAPDH knockdown significantly inhibited the cell proliferation and migration/invasion in vivo. In summary, GAPDH may not be an appropriate internal control for gene expression studies, especially in cancer research. The role of GAPDH in cancer development and progression should be further examined in pre-clinical and clinical studies.
Zhu G, etal., Biochem Biophys Res Commun 2001 Mar 9;281(4):951-6.
Messenger RNA differential display was applied to screen for the blood glucose-regulated genes in SD rat skeletal muscle. The rat homologue of the mouse prominin was thus identified. Comparing to its mouse and human homologues, fudenine was C-terminal truncated due to a single nucleotide deletion. H
owever, its mitochondrial energy transfer signature peptide PQDLVKKLI remained intact. Fudenine, an 592-amino acid containing, 66-kDa glycoprotein, is a novel plasma membrane protein with four transmembrane segments flanking by two large glycosylated extracellular domains. Although it is devoid of the last transmembrane domain comparing to its homologues, fudenine also locates in cell membrane by transfection of fusion plasmid pFudenine-EGFP into CBRH7919 cell and L-6TG cell. Overexpression of fudenine in CBRH7919 cell line up-regulated the mRNA level of GAPDH (3-phosphate glyceraldehyde dehydrogenase), while long-term glucose exposure resulted to reduced GAPDH expression. Since high blood glucose level induced the expression of fudenine in skeletal muscle, which in turn up-regulated the expression of GAPDH, we propose that fudenine might be a candidate gene for diabetes mellitus. Copyright 2001 Academic Press.
Huo J, etal., Neuroscience. 2016 Aug 25;330:171-80. doi: 10.1016/j.neuroscience.2016.05.054. Epub 2016 May 30.
The glyceraldehyde-3-phosphate dehydrogenase (GAPDH)/Siah1 signaling pathway has been recognized as a sensor of nitric oxide (NO). It is associated with a variety of injurious conditions, suggesting its therapeutic potential for spinal cord injury (SCI). Siveles
tat sodium (SIV), a neutrophil elastase (NE) inhibitor initially used to treat acute lung injury, has been known to protect against compression-induced and ischemic SCI. However, little is known about the relationship between the GAPDH/Siah1 cascade and SIV. Thus, we aimed to assess the role of GAPDH/Siah1 cascade in traumatic SCI and its possible link with SIV. Rats were assigned to four groups: sham group, SCI group, 5-mg/kg SIV group, and 10-mg/kg SIV. The traumatic SCI was induced by dropping a 10-g impactor from a height of 25mm on the dorsal surface of T9 and T10. SIV was injected intraperitoneally immediately after surgery. Our results showed that the nuclear translocation of GAPDH was induced together with the nuclear translocation of Siah1 and the formation of the GAPDH/Siah1 complex in the spinal cord after traumatic SCI. However, the activation of the GAPDH/Siah1 cascade was attenuated by treatment with SIV. We also found that SIV suppressed apoptosis, NE and inducible nitric oxide synthase (iNOS) protein expressions, the number of NE and iNOS immunostained cells, the production of interleukin (IL)-1ß and tumor necrosis factor-alpha (TNF-α), and the activation of nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) signaling in the spinal cord. The behavioral tests showed that SIV promoted functional recovery after traumatic SCI as reflected in the sustained increase in the Basso-Beattie-Bresnahan (BBB) scores throughout the observation period. In conclusion, our results reveal GAPDH/Siah1 as a novel signaling pathway during the progression of SCI, which can be blocked by SIV.
Liu L, etal., PLoS One. 2015 Aug 10;10(8):e0135425. doi: 10.1371/journal.pone.0135425. eCollection 2015.
BACKGROUND: Accumulating evidence has demonstrated that the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a part of Lewy body inclusions and involves the pathogenesis of Parkinson's disease (PD). However, it remains unknown whether or not genetic variation
at the GAPDH locus contributes to the risk for PD. METHODS: A total of 302 sporadic PD patients and 377 control subjects were recruited in our study for assessing two single nucleotide polymorphisms (rs3741918 and rs1060619) in the GAPDH gene. Both allelic association and additive models were used to analyze association between GAPDH variants and risk for PD. RESULTS: Both polymorphisms were significantly associated with risk for PD after correction by Bonferroni multiple testing. The minor allele of rs3741918 was associated with decreased risk of sporadic PD (allelic contrast, OR = 0.74, 95% CI: 0.59-0.93, corrected P = 0.028; additive model, OR = 0.73, 95% CI: 0.58-0.92, corrected P = 0.018). While for the rs1060619 locus, the minor allele conferred increased risk for PD (allelic contrast, OR = 1.41, 95% CI: 1.14-1.75, corrected P = 0.007; additive model, OR = 1.43, 95% CI: 1.15-1.79, corrected P = 0.002). CONCLUSION: Our study indicates that GAPDH variants confer susceptibility to sporadic PD in a Chinese Han population, which is consistent with the role of GAPDH protein in neuronal apoptosis. To our knowledge, this is the first study of genetic association between GAPDH locus and risk for PD in the Chinese population.
Lazarev VF, etal., Biochem Biophys Res Commun. 2016 Feb 12;470(3):766-71. doi: 10.1016/j.bbrc.2015.12.076. Epub 2015 Dec 20.
The Hsp70 chaperone is known to elicit cytoprotective activity and this protection has a negative impact in anti-tumor therapy. In cancer cells subjected to oxidative stress Hsp70 may bind damaged polypeptides and proteins involved in apoptosis signaling. Since one of the important targets of oxida
tive stress is glyceraldehyde-3-phospate dehydrogenase (GAPDH) we suggested that Hsp70 might elicit its protective effect by binding GAPDH. Microscopy data show that in C6 rat glioma cells subjected to hydrogen peroxide treatment a considerable proportion of the GAPDH molecules are denatured and according to dot ultrafiltration data they form SDS-insoluble aggregates. Using two newly developed assays we show that Hsp70 can bind oxidized GAPDH in an ATP-dependent manner. Pharmacological up- or down-regulation of Hsp70 with the aid of U133 echinochrome or triptolide, respectively, reduced or increased the number of C6 glioma cells containing GAPDH aggregates and dying due to treatment with hydrogen peroxide. Using immunoprecipitation we found that Hsp70 is able to sequester aggregation-prone GAPDH and this may explain the anti-oxidative power of the chaperone. The results of this study led us to conclude that in cancer cells constantly exposed to conditions of oxidative stress, the protective power of Hsp70 should be abolished by specific inhibitors of Hsp70 expression.
Cha SJ, etal., J Exp Med. 2016 Aug 22. pii: jem.20160059.
Malaria transmission begins when an infected mosquito delivers Plasmodium sporozoites into the skin. The sporozoite subsequently enters the circulation and infects the liver by preferentially traversing Kupffer cells, a macrophage-like component of the liver sinusoidal lining. By screening a phage d
isplay library, we previously identified a peptide designated P39 that binds to CD68 on the surface of Kupffer cells and blocks sporozoite traversal. In this study, we show that the P39 peptide is a structural mimic of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) on the sporozoite surface and that GAPDH directly interacts with CD68 on the Kupffer cell surface. Importantly, an anti-P39 antibody significantly inhibits sporozoite liver invasion without cross-reacting with mammalian GAPDH. Therefore, Plasmodium-specific GAPDH epitopes may provide novel antigens for the development of a prehepatic vaccine.
Soltany-Rezaee-Rad M, etal., Gastroenterol Res Pract. 2014;2014:185035. doi: 10.1155/2014/185035. Epub 2014 Jan 8.
To find genes involved in tumorigenesis and the development of esophageal cancer, the suppression subtractive hybridization (SSH) method was used to identify genes that are overexpressed in esophageal cancer tissues compared to normal esophageal tissues. In our SSH library, the forkhead box O3 (FOXO
3), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and myeloid differentiation primary response 88 (MYD88) genes were the most highly upregulated genes, and they were selected for further studies because of their potential role in the induction of autophagy. Upregulation of these genes was also observed in clinical samples using qRT-PCR. In addition, coexpression analysis of the autophagy-related genes Beclin1, ATG12, Gabarapl, PIK3C3, and LC3 demonstrated a significant correlation between the differentially overexpressed genes and autophagy. Autophagy is an important mechanism in tumorigenesis and the development of chemoresistance in cancer cells. The upregulation of FOXO3, GAPDH, and MYD88 variants in esophageal cancer suggests a role for autophagy and provides new insight into the biology of esophageal cancer. We propose that FOXO3, GAPDH, and MYD88 are novel targets for combating autophagy in esophageal cancer.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) influences cytotoxicity, translocating to the nucleus during apoptosis. Here we report a signalling pathway in which nitric oxide (NO) generation that follows apoptotic stimulation elicits S-nitrosylation of ... (more)
n style='font-weight:700;'>GAPDH, which triggers binding to Siah1 (an E3 ubiquitin ligase), nuclear translocation and apoptosis. S-nitrosylation of GAPDH augments its binding to Siah1, whose nuclear localization signal mediates translocation of GAPDH. GAPDH stabilizes Siah1, facilitating its degradation of nuclear proteins. Activation of macrophages by endotoxin and of neurons by glutamate elicits GAPDH-Siah1 binding, nuclear translocation and apoptosis, which are prevented by NO deletion. The NO-S-nitrosylation-GAPDH-Siah1 cascade may represent an important molecular mechanism of cytotoxicity.
Kim SH, etal., Biomed Res Int. 2015;2015:292454. doi: 10.1155/2015/292454. Epub 2015 Oct 7.
The study quantified the relative absolute PSCA level in relation to the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) level in the peripheral blood of 478 hormone-naive prostate cancer (PC) patients who underwent radical prostatectomy from 2005 to 2012 and e
valuated its prognostic significance as a risk factor for predicting biochemical recurrence (BCR), compared to known parameters. Nested real-time polymerase chain reaction (RT-PCR) and gel electrophoresis detected PSCA levels and measured the PSCA/GAPDH ratio. Clinicopathological data from the institutional database were examined to determine the adequate cut-off level to predict postoperative BCR. A total of 110 patients had a positive PSCA result (23.0%) via RT-PCR (mean blood ratio 1.1 +/- 0.4). The BCR was significantly higher in the PSCA-positive detection group (p = 0.009). A multivariate model was created to show that a PSCA/GAPDH ratio between 1.0 and 1.5 (HR 12.722), clinical T2c stage (HR 0.104), preoperative PSA (HR 1.225), extraprostatic capsule extension (HR 0.006), lymph node dissection (HR 16.437), and positive resection margin (HR 27.453) were significant predictive factors for BCR (p < 0.05). The study showed successful quantification of PSCA with its significance for BCR-related risk factor; however, further studies are needed to confirm its clinical predictive value.
