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Exogenous oxidative stress induces Ca 2+ release in the yeast Saccharomyces cerevisiae
Author(s) -
Popa ClaudiaValentina,
Dumitru Ioana,
Ruta Lavinia L.,
Danet Andrei F.,
Farcasanu Ileana C.
Publication year - 2010
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2010.07794.x
Subject(s) - saccharomyces cerevisiae , yeast , oxidative stress , chemistry , oxidative phosphorylation , microbiology and biotechnology , stress (linguistics) , biochemistry , biophysics , biology , linguistics , philosophy
The Ca 2+ ‐dependent response to oxidative stress caused by H 2 O 2 or tert ‐butylhydroperoxide ( t BOOH) was investigated in Saccharomyces cerevisiae cells expressing transgenic cytosolic aequorin, a Ca 2+ ‐dependent photoprotein. Both H 2 O 2 and t BOOH induced an immediate and short‐duration cytosolic Ca 2+ increase that depended on the concentration of the stressors. Sublethal doses of H 2 O 2 induced Ca 2+ entry into the cytosol from both extracellular and vacuolar sources, whereas lethal H 2 O 2 shock mobilized predominantly the vacuolar Ca 2+ . Sublethal and lethal t BOOH shocks induced mainly the influx of external Ca 2+ , accompanied by a more modest vacuolar contribution. Ca 2+ transport across the plasma membrane did not necessarily involve the activity of the Cch1p/Mid1p channel, whereas the release of vacuolar Ca 2+ into the cytosol required the vacuolar channel Yvc1p. In mutants lacking the Ca 2+ transporters, H 2 O 2 or t BOOH sensitivity correlated with cytosolic Ca 2+ overload. Thus, it appears that under H 2 O 2 ‐induced or t BOOH‐induced oxidative stress, Ca 2+ mediates the cytotoxic effect of the stressors and not the adaptation process.