Expression of CMK2 is controlled by the general stress-response transcriptional factor Msn2 through a single STRE site in budding yeast.

Mammalian calcium/calmodulin-dependent protein kinase II (CaMKII) is a memory molecule in the brain, and regulates fatty acids and lipid metabolism. As a yeast homolog of CaMKII, Cmk2 is a negative feed-back regulator of calcium signaling in Saccharomyces cerevisiae. Previous systemic studies have shown that 42 transcription factors (TFs) are involved in the control of CMK2 expression under various conditions other than calcium stress, but only one, Crz1, is reported to directly regulate CMK2 expression in response to calcium stress. Here, we show that other 26 TFs, Adr1, Aft2, Cad1, Cst6, Cup2, Dal81, Dal82, Flo8, Gcr2, Haa1, Hfi1, Msn2, Oaf1, Pho4, Ppr1, Rfx1, Rgm1, Rpn4, Sfp1, SIp3, Smp1, Spt10, Stp1, Sum1, Swi4 and Tup1, are involved in the positive control of CMK2 transcription, with 10 of them being calcium stress-specific. In contrast, other four TFs, Hir2, Rph1, Sin3 and Uga3, negatively regulates CMK2 transcription independent of calcium stress. Therefore, multiple TFs directly or indirectly control the transcription of CMK2 in yeast cells. EMSA and ChIP analysis demonstrate that the general stress-responsive Msn2 directly controls the expression of CMK2 through one STRE site, 5' C-155CCCT 3', in its promoter. Our genetic study indicates that Crz1 is epistatic to Msn2 in controlling CMK2 expression and the calcium sensitivity of yeast cells in response to calcium stress. This work provides important clues to the study on the regulation of CaMKII expression in mammalian cells.