Oxidation of the active site cysteine residue of glyceraldehyde-3-phosphate dehydrogenase to the hyper-oxidized sulfonic acid form is favored under crowded conditions

Mia R. Glover, Michael J. Davies, Eduardo Fuentes-Lemus*

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

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Abstract

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a key cellular enzyme, with major roles in both glycolysis, and ‘moonlighting’ activities in the nucleus (uracil DNA glycosylase activity, nuclear protein nitrosylation), as a regulator of mRNA stability, a transferrin receptor, and as an antimicrobial agent. These activities are dependent, at least in part, on the integrity of an active site Cys residue, and a second neighboring Cys. These residues are differentially sensitive to oxidation, and determine both its catalytic activity and the redox signaling capacity of the protein. Such Cys modification is critical to cellular adaptation to oxidative environments by re-routing metabolic pathways to favor NADPH generation and antioxidant defenses. Despite the susceptibility of GAPDH to oxidation, it remains a puzzle as to how this enzyme acts as a redox signaling hub for oxidants such as hydrogen peroxide (H2O2) in the presence of high concentrations of specialized high-efficiency peroxide-removing enzymes. One possibility is that crowded environments, such as the cell cytosol, alter the oxidation pathways of GAPDH. In this study, we investigated the role of crowding (induced by dextran) on H2O2- and SIN-1-induced GAPDH oxidation, with data for crowded and dilute conditions compared. LC-MS/MS data revealed a lower extent of modification of the catalytic Cys under crowded conditions (i.e. less monomer units modified), but enhanced formation of the sulfonic acid resulting from hyper-oxidation. This effect was not observed with SIN-1. These data indicate that molecular crowding can modulate the oxidation pathways of GAPDH and its extent of oxidation and inactivation.

OriginalsprogEngelsk
TidsskriftFree Radical Biology and Medicine
Vol/bind212
Sider (fra-til)1-9
Antal sider9
ISSN0891-5849
DOI
StatusUdgivet - 2024

Bibliografisk note

Funding Information:
Authors acknowledge funding from SFRR-E/Oxygen Club of California (OCC) for an Early Career Researcher (ECR) fellowship to EFL , and from the Novo Nordisk Foundation (Laureate grant: NNF20SA0064214 ) to MJD.

Publisher Copyright:
© 2023 The Authors

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