Glutathione peroxidase induction protects Saccharomyces cerevisiae sod1deltasod2delta double mutants against oxidative damage

• Autor(a) principal: Manfredini, Vanusa
• Data de Publicação: 2004
• Outros Autores: Roehrs, Rafael, Peralba, Maria do Carmo Ruaro, Henriques, João Antonio Pêgas, Saffi, Jenifer, Ramos, Ana Ligia Lia de Paula, Benfato, Mara da Silveira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/21176
• topic: Catalase; Glutationa; Saccharomyces cerevisiae : Gene : Mutacao; Superóxido dismutase; Peróxido de hidrogênio; Espécies reativas de oxigênio; Catalase; Superoxide dismutase; Glutathione; Hydrogen peroxide; Saccharomyces cerevisiae; Reactive oxygen species

Saccharomyces cerevisiae mutants deficient in superoxide dismutase genes (sod1∆, sod2∆and the double mutant) were subjected to H2O2 stress in the stationary phase. The highest sensitivity was observed in the sod2∆mutant, while the sod1∆sod2∆double mutant was not sensitive. sod mutants had lower catalase activity (44%) than wildtype cells, independent of H2O2 stress. Untreated cells of sod1∆sod2∆ double mutants showed increased glutathione peroxidase activity (126%), while sod1∆had lower activity (77%) than the wild type. Glutathione levels in sod1∆were increased (200-260%) after exposure to various H2O2 concentrations. In addition, the highest malondialdehyde levels could be observed without H2O2 treatment in sod1∆ (167%) and sod2∆(225%) mutants. In contrast, the level of malondialdehyde in the sod1∆sod2∆double mutant was indistinguishable from that of the wild type. These results suggest that resistance to H2O2 by sod1∆sod2∆cells depends on the induction of glutathione peroxidase and is independent of catalase, and that glutathione is a primary antioxidant in the defense against H2O2 in stationary phase sod1∆ mutants.