Adaptation to tert-butyl hydroperoxide at a plasma membrane level in the fission yeast Schizosaccharomyces pombe parental strain and its t-BuOOH-resistant mutant

The one‐gene mutant hyd1‐190 of the fission yeast Schizosaccharomyces pombe displayed four‐fold resistance to tert‐butyl hydroperoxide (t‐BuOOH) in comparison with its parental strain hyd+. The cells of hyd1‐190 exhibited a quantitative alteration in the sterol content and hence in the fatty acid composition of the plasma membrane, reflected in a two‐fold amphotericin B sensitivity, increased rigidity of the plasma membrane, revealed by an elevated (Δ7.9 °C) phase‐transition temperature, measured by means of electron paramagnetic resonance spectroscopy, and a significantly decreased uptake of glycerol. Treatment of the strains with a subinhibitory concentration (0.2 mM) of t‐BuOOH induced adaptation via modification of the sterol and fatty acid compositions, resulting in increased (Δ3.95 °C) and decreased (Δ6.83 °C) phase‐transition temperatures of the hyd+ and hyd1‐190 strains, respectively, in order to defend the cells against the consequences of t‐BuOOH‐induced external oxidative stress. However, in contrast with hyd+, hyd1‐190 lacks the ability to adapt to t‐BuOOH at a cell level.