Involvement of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase in response to oxidative stress.
Glyceraldehyde-3-phosphate dehydrogenases catalyze key steps in energy and reducing power partitioning in cells of higher plants. Because non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (NP-Ga3PDHase) is involved in the production of reductive power (NADPH) in the cytosol, its behavior under oxidative stress conditions was analyzed. The specific activity of the enzyme was found to increase up to 2-fold after oxidative conditions imposed by methylviologen in wheat and maize seedlings. Under moderate oxidant concentration, lack of mRNA induction was observed. The increase in specific activity would thus be a consequence of a significant stability of NP-Ga3PDHase. Our results suggest that the enzyme could be modified by oxidation of cysteine residues, but formation of disulfide bridges is dependent on levels of divalent cations and 14-3-3 proteins. The latter differential effect could be critical to relatively maintain energy and reductant levels in the cytoplasm of plant cells under oxidative stress.
Bustos
Diego M
DM
Instituto Tecnológico de Chascomùs (IIB-INTECH), Chascomùs, Argentina.
Bustamante
Claudia A
CA
Iglesias
Alberto A
AA
D004795:Enzyme Stability / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology; D014908:Triticum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D003313:Zea mays / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics
D016877:Oxidants; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D010269:Paraquat