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Characterization of Saccharomyces cerevisiae ubiquinone‐deficient mutants
Author(s) -
Schultz Jeffery R.,
Clarke Catherine F.
Publication year - 1999
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520090206
Subject(s) - ubiquinol , biochemistry , antioxidant , oxidative stress , superoxide dismutase , catalase , chemistry , saccharomyces cerevisiae , wild type , mutant , endogeny , coenzyme q – cytochrome c reductase , yeast , biology , mitochondrion , gene , cytochrome c
Ubiquinol (QH 2 ) is a lipid‐soluble molecule that participates in cellular redox reactions. Previous studies have shown that yeast mutants lacking QH 2 are hypersensitive to treatment with polyunsaturated fatty acids (PUFAs) indicating that QH 2 can function as an antioxidant in vivo. In this study the effect of 1 mM linolenic acid on levels of Q 6 and Q 6 H 2 is assessed in both wild‐type and respiration‐deficient ( atp2 Δ) strains. The response of Q‐deficient mutants to other forms of oxidative stress is further characterized to define those conditions where QH 2 acts as an antioxidant. Endogenous antioxidant defense systems were also assessed in wild‐type, Q‐deficient, and atp2 Δ strains. Superoxide dismutase (SOD) activity decreased and catalase activity increased in both Q‐deficient and atp2 Δ mutants compared to wild‐type cells, suggesting that such changes result from the loss of respiration rather than the lack of Q.