The calcineurin-responsive transcription factor Crz1 regulates the expression of CMK2 via a sole CDRE site in its promoter in budding yeast

As a yeast homolog of mammalian calcium/calmodulin-dependent protein kinase II (CaMKII), Cmk2 functions as a negative regulator of calcium signaling in Saccharomyces cerevisiae. We show here that the transcription expression of CMK2 is controlled mainly by the transcription factor Crz1 and also by other factor(s) in response to calcium stress. There are four potential binding sites (calcium/calcineurin-dependent responsive elements; CDREs) for Crz1 in the promoter of CMK2. Through mutational analysis, we demonstrated that mutation of only the site (5' G_-177AGGCT 3'), but not the other three sites, abolished the calcium-induction activity of the CMK2p-lacZ reporter. EMSA analysis indicated that the C-terminal region of Crz1, which contains its DNA-binding domains can bind to this site in vitro. ChIP analysis revealed that Crz1 binds to the promoter region containing this site in vivo. Therefore, the transcription expression of CMK2 is controlled by Crz1 through a sole CDRE site the CMK2 promoter.