OXIDATIVE STRESS-RESPONSE IN YEAST - EFFECT OF GLUTATHIONE ON ADAPTATION TO HYDROGEN-PEROXIDE STRESS IN SACCHAROMYCES-CEREVISIAE

Role of intracellular glutathione in the response of Saccharomyces cer evisiae to H2O2 was investigated. Depletion of cellular glutathione or inhibition of gamma-glutamylcysteine synthetase (GSH-I) enhanced the sensitivity to H2O2 and suppressed the adaptation to H2O2. A mutant de ficient in GSH-I also showed the hypersensitivity and could not adapt to H2O2. Incubation of the cell with amino acids constituting glutathi one (L-Glu, L-Cys, Gly) increased the intracellular glutathione conten t, and subsequently the cell acquired resistance against H2O2. These r esults strongly suggest that intracellular glutathione plays an import ant role in the adaptive response in S. cerevisiae to oxidative damage .