Premium
tert ‐Butyl hydroperoxide‐induced differing plasma membrane and oxidative stress processes in yeast strains BY4741 and erg5Δ
Author(s) -
Gazdag Zoltán,
Máté Gábor,
Čertik Milan,
Türmer Katalin,
Virág Eszter,
Pócsi István,
Pesti Miklós
Publication year - 2014
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201300925
Subject(s) - ergosterol , oxidative stress , biochemistry , chemistry , sterol , antioxidant , glutathione , superoxide dismutase , intracellular , catalase , membrane fluidity , fatty acid , enzyme , membrane , cholesterol
The molecular mechanism of tert ‐butyl hydroperoxide ( t ‐BuOOH) elicited cytotoxicity and the background of t ‐BuOOH sensitivity were studied in the Saccharomyces cerevisiae ergosterol‐less gene deletion mutant erg5Δ and its parental strain BY4741. In comparison to BY4741, untreated erg5Δ cells exhibited alterations in sterol and fatty acid compositions of the plasma membrane, as reflected by the inherent amphotericin B resistance, an elevated level (31%) of plasma membrane rigidity and a decreased uptake of glycerol. Surprisingly, the untreated erg5Δ cells exhibited an unbalanced intracellular redox state, accompanied by the continuous upregulation of the antioxidant enzymes Mn superoxide dismutase, catalase, and glutathione S‐transferase, which resulted in decreased specific concentrations of superoxide and peroxides and elevated levels of the hydroxyl radical and thiols. The 2.5‐fold sensitivity of erg5Δ to t ‐BuOOH suggested that the oxidative stress adaptation processes of the mutant could not restore the redox homeostasis of the cells and there is an overlap between sterol and redox homeostases. t ‐BuOOH treatment of both strains induced adaptive modification of the sterol and fatty acid compositions, increased the plasma membrane fluidity and elevated the specific activities of most antioxidant enzymes through specific regulation processes in a strain‐dependent manner.