title: A proton relay enhances H2O2 sensitivity of GAPDH to facilitate metabolic adaptation.
abstract: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is sensitive to reversible oxidative inactivation by hydrogen peroxide (H2O2). Here we show that H2O2 reactivity of the active site thiolate (C152) is catalyzed by a previously unrecognized mechanism based on a dedicated proton relay promoting leaving group departure. Disruption of the peroxidatic reaction mechanism does not affect the glycolytic activity of GAPDH. Therefore, specific and separate mechanisms mediate the reactivity of the same thiolate nucleophile toward H2O2 and glyceraldehyde 3-phosphate, respectively. The generation of mutants in which the glycolytic and peroxidatic activities of GAPDH are comprehensively uncoupled allowed for a direct assessment of the physiological relevance of GAPDH H2O2 sensitivity. Using yeast strains in which wild-type GAPDH was replaced with H2O2-insensitive mutants retaining full glycolytic activity, we demonstrate that H2O2 sensitivity of GAPDH is a key component of the cellular adaptive response to increased H2O2 levels.
authors.affiliation: Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Peralta
authors.affiliation: 1] Molecular Biomechanics, Heidelberg Institute of Theoretical Studies, Heidelberg, Germany. [2] Faculty of Chemistry, University of Heidelberg, Heidelberg, Germany.
authors.forename: Agnieszka K
authors.initials: AK
authors.lastname: Bronowska
authors.affiliation: Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Bruce
authors.initials: B
authors.lastname: Morgan
authors.affiliation: 1] Department of Molecular Immunology and Toxicology, National Institute of Oncology, Budapest, Hungary. [2] Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary..
authors.forename: Éva
authors.initials: É
authors.lastname: Dóka
authors.affiliation: Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Koen
authors.initials: K
authors.lastname: Van Laer
authors.affiliation: Department of Molecular Immunology and Toxicology, National Institute of Oncology, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Nagy
authors.affiliation: Molecular Biomechanics, Heidelberg Institute of Theoretical Studies, Heidelberg, Germany.
authors.forename: Frauke
authors.initials: F
authors.lastname: Gräter
authors.affiliation: Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Tobias P
authors.identifier: 000000031367973X
authors.initials: TP
authors.lastname: Dick
mesh_terms: D000220:Adaptation, Biological; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009154:Mutation; D010084:Oxidation-Reduction; D011522:Protons; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D011522:Protons; D029701:Saccharomyces cerevisiae Proteins; D006861:Hydrogen Peroxide; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating); C465224:TDH1 protein, S cerevisiae; C465225:TDH2 protein, S cerevisiae; C465226:TDH3 protein, S cerevisiae; D003545:Cysteine