Deletion of PDR5 gene (Delta pdr5) in Saccharomyces cerevisiae led to increased resistance to calcium. The cellular Ca2+ level in the presence of high calcium as estimated by reporter assay in Delta pdr5 cells was significantly lower than that in wild-type cells. Membrane Pdr5p levels diminished rapidly during incubation with high calcium in a manner dependent on calcineurin and Pep4p, suggesting a feedback regulatory mechanism for Pdr5p abundance.