title: Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) Protein-Protein Interaction Inhibitor Reveals a Non-catalytic Role for GAPDH Oligomerization in Cell Death.
abstract: 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 by δ protein kinase C (δPKC) inhibits this GAPDH-dependent mitochondrial elimination. δPKC 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 (ψGAPDH) peptide, an inhibitor of δPKC-mediated GAPDH phosphorylation that does not inhibit the phosphorylation of other δPKC substrates. Unexpectedly, ψGAPDH decreased mitochondrial elimination and increased cardiac damage in an animal model of heart attack. Either treatment with ψGAPDH or direct phosphorylation of GAPDH by δPKC 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, ψGAPDH peptide, with interesting properties. ψGAPDH peptide is an inhibitor of the interaction between δPKC and GAPDH and of the resulting phosphorylation of GAPDH by δPKC. ψGAPDH peptide is also an inhibitor of GAPDH oligomerization and thus an inhibitor of GAPDH glycolytic activity. Finally, we found that ψGAPDH 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 ψGAPDH peptide-based therapy.
authors.affiliation: From the Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305-5174 and nirqvit@stanford.edu.
authors.forename: Nir
authors.initials: N
authors.lastname: Qvit
authors.affiliation: From the Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305-5174 and.
authors.forename: Amit U
authors.initials: AU
authors.lastname: Joshi
authors.affiliation: From the Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305-5174 and.
authors.forename: Anna D
authors.initials: AD
authors.lastname: Cunningham
authors.affiliation: the Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil.
authors.forename: Julio C B
authors.initials: JC
authors.lastname: Ferreira
authors.affiliation: From the Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305-5174 and mochly@stanford.edu.
authors.forename: Daria
authors.initials: D
authors.lastname: Mochly-Rosen
mesh_terms: D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D051379:Mice; D010455:Peptides / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D051745:Protein Kinase C-delta / Q000235:genetics / Q000378:metabolism*; D055503:Protein Multimerization / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D015027:Zebrafish
chemical_list: D004791:Enzyme Inhibitors; D010455:Peptides; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating); C497260:Prkcd protein, rat; D051745:Protein Kinase C-delta
keywords: Pseudosubstrate; docking; glyceraldehyde-3-phosphate dehydrogenase (GAPDH); mitochondria elimination; oligomerization; oxidative stress; peptides; protein kinase; protein kinase C (PKC); protein structure