Metabolic Switch
GAPDH acts as reversible metabolic switch under oxidative stress. When cells are exposed to oxidants, they need excessive amounts of the antioxidant cofactor NADPH. In the cytosol, NADPH is reduced from NADP+ by several enzymes, three of them catalyze the first steps of the Pentose phosphate pathway. Oxidant-treatments cause an inactivation of GAPDH. This inactivation re-routes temporally the metabolic flux from glycolysis to the Pentose Phosphate Pathway, allowing the cell to generate more NADPH. Under stress conditions, NADPH is needed by some antioxidant-systems including glutaredoxin and thioredoxin as well as being essential for the recycling of gluthathione.
Read more about this topic: Glyceraldehyde 3-phosphate Dehydrogenase
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