Oxidative stress response in eukaryotes: effect of glutathione, superoxide dismutase and catalase on adaptation to peroxide and menadione stresses inSaccharomyces cerevisiae

Abstract

Aiming to clarify the mechanisms by which eukaryotes acquire tolerance to oxidative stress, adaptive and cross-protection responses to oxidants were investigated in Saccharomyces cerevisiae. Cells treated with sub-lethal concentrations of menadione (a source of superoxide anions) exhibited cross-protection against lethal doses of peroxide; however, cells treated with H2O2 did not acquire tolerance to a menadione stress, indicating that menadione response encompasses H2O2 adaptation. Although, deficiency in cytoplasmic superoxide dismutase (Sod1) had not interfered with response to superoxide, cells deficient in glutathione (GSH) synthesis were not able to acquire tolerance to H2O2 when pretreated with menadione. These results suggest that GSH is an inducible part of the superoxide adaptive stress response, which correlates with a decrease in the levels of intracellular oxidation. On the other hand, neither the deficiency of Sod1 nor in GSH impaired the process of acquisition of tolerance to H2O2 achieved by a mild pretreatment with peroxide. Using a strain deficient in the cytosolic catalase, we were able to conclude that the reduction in lipid peroxidation levels produced by the adaptive treatment with H2O2 was dependent on this enzyme. Corroborating these results, the pretreatment with low concentrations of H2O2 promoted an increase in catalase activity.

Saccharomyces cerevisiae KNU5377 Stress Response during High-Temperature Ethanol Fermentation

“…Yap1 is a basic leucine zipper required for oxidative stress tolerance. Many ethanol-induced genes contain a Yap1 binding motif (Eastmond and Nelson, 2006;Fernandes et al, 2007;Herrero et al, 2008). However, the functions of Yap1 in ethanol tolerance have been not characterized.…”

Inorganic Chemistry of Defensive Peroxidases in the Human Oral Cavity

“…Cysteine (Cys) and methionine (Met) are usually the most reactive amino acid residues toward two-electron oxidants (because sulfurcontaining compounds tend to be good nucleophiles) and are therefore often the first targets of two-electron oxidants (Hawkins et al, 2003). It is not a coincidence that the cytoplasms of eukaryotes (Meister, 1988;Fernandes et al, 2007) and many prokaryotes (Fahey et al, 1978;Smirnova and Oktyabrsky, 2005) contain high concentrations of GSH (a tripeptide containing Cys, which is used to combat oxidative stress by two-electron oxidants that operate by the aforementioned electrophilic mechanism) (Meister, 1988). It should be noted that glutathione also erects a significant defense against radical species (Sitte and Von Zglinicki, 2003;Djordjevic, 2004) (Table 2).…”

Decarbonylated cyclophilin A Cpr1 protein protects KNU5377Y when exposed to stress induced by menadione

“…S3), Yap1, and Msn2 in the kwt cells were higher than those in the bwt cells, which enable rapid and efficient remodeling of yeast genome expression in response to environmental change induced by MD. It is well known that transcription factors and antioxidant enzymes play very important roles in cellular defense against oxidative stress in yeast (Jamieson 1998;Moradas-Ferreira and Costa 2000;Fernandes et al 2007;Herrero et al 2008), which affects redox balance within the cells.…”

“…The measurement of cellular NADPH was carried out as in previous studies (Fernandes et al 2007;Tan et al 2009). NADPH levels were expressed as an nanomole per milligram protein.…”