Role of thioredoxins in the response of Saccharomyces cerevisiae to oxidative stress induced by hydroperoxides.

摘要: Glutaredoxins and thioredoxins are highly conserved, small, heat-stable oxidoreductases. The yeast Saccharomyces cerevisiae contains two gene pairs encoding cytoplasmic glutaredoxins (GRX1, GRX2) (TRX1, TRX2), we have used multiple mutants to determine their roles in mediating resistance oxidative stress caused by hydroperoxides. Our data indicate that TRX2 plays the predominant role, as lacking hypersensitive, containing resistant these oxidants. However, requirement for is only apparent during stationary phase growth, present three lines of evidence thioredoxin isoenzymes actually redundant activities antioxidants. First, trx1 trx2 show wild-type hydroperoxide exponential growth; secondly, overexpression either TRX1 or leads increased hydroperoxides; and, thirdly, both Trx1 Trx2 equally able act cofactors peroxidase, Tsa1. antioxidant activity required survival cells well protection against correlates with an increase expression TRX2. We this growth dependent on enzyme Tsa1, regulation redox state protein-bound levels low-molecular-weight glutathione.