Superoxide dismutase activity is essential for stationary phase survival in Saccharomyces cerevisiae. Mitochondrial production of toxic oxygen species in vivo.

Authors: Longo VD; Gralla EB; Valentine JS

Abstract: Yeast lacking copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (SOD), catalase T, or metallothionein were studied using long-term stationary phase (10-45 days) as a simple model system to study the roles of antioxidant enzymes in aging. In well aerated cultures, the lack of either SOD resulted in dramatic loss of viability over the first few weeks of culture, with the CuZnSOD mutant showing the more severe defect. The double SOD mutant died within a few days. The severity reversed in low aeration; the CuZnSOD mutant remained viable longer than the manganese SOD mutant. To test whether reactive oxygen species generated during respiration play an important role in the observed cellular death, growth in nonfermentable carbon sources was measured. All strains grew under low aeration, indicating respiratory competence. High aeration caused much reduced growth in single SOD mutants, and the double mutant failed to grow. However, removal of respiration via another mutation dramatically increased short term survival and reversed the known air-dependent methionine and lysine auxotrophies. Our results suggest strongly that mitochondrial respiration is a major source of reactive oxygen species in vivo, as has been shown in vitro, and that these species are produced even under low aeration.

Keywords: Mitochondria/*metabolism; Mutation; Oxygen/metabolism; Reactive Oxygen Species/*metabolism; Saccharomyces cerevisiae/*enzymology/growth & development/metabolism; Superoxide Dismutase/genetics/*metabolism
Journal: The Journal of biological chemistry
Volume: 271
Issue: 21
Pages: 12275-80
Date: May 24, 1996
PMID: 8647826
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Citation:

Longo VD, Gralla EB, Valentine JS (1996) Superoxide dismutase activity is essential for stationary phase survival in Saccharomyces cerevisiae. Mitochondrial production of toxic oxygen species in vivo. The Journal of biological chemistry 271: 12275-80.


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