Calcium signaling mediates the response to cadmium toxicity in Saccharomyces cerevisiae cells

The involvement of Ca 2+ in the response to high Mn 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ , and Hg 2+ was investigated in Saccharomyces cerevisiae . The yeast cells responded through a sharp increase in cytosolic Ca 2+ when exposed to Cd 2+ , and to a lesser extent to Cu 2+ , but not to Mn 2+ , Co 2+ , Ni 2+ , Zn 2+ , or Hg 2+ . The response to high Cd 2+ depended mainly on external Ca 2+ (transported through the Cch1p/Mid1p channel) but also on vacuolar Ca 2+ (released into the cytosol through the Yvc1p channel). The adaptation to high Cd 2+ was influenced by perturbations in Ca 2+ homeostasis. Thus, the tolerance to Cd 2+ often correlated with sharp Cd 2+ ‐induced cytosolic Ca 2+ pulses, while the Cd 2+ sensitivity was accompanied by the incapacity to rapidly restore the low cytosolic Ca 2+ .