CLN1 and Its Repression by Xbp1 Are Important for Efficient Sporulation in Budding Yeast

摘要: Xbp1, a transcriptional repressor of Saccharomyces cerevisiae with homology to Swi4 and Mbp1, is induced by stress starvation during the mitotic cycle. It also late in meiotic Using RNA differential display, we find that genes encoding three cyclins (CLN1, CLN3, CLB2), CYS3, SMF2 are downregulated when Xbp1 overexpressed can bind sequences their promoters. During meiosis, XBP1 highly its mRNA appears at same time as DIT1 mRNA, but expression remains high for up 24 h. As such, it represents new class meiosis-specific genes. Xbp1-deficient cells capable forming viable gametes, although ascus formation delayed several hours. Furthermore, target normally repressed loss results derepression. Interestingly, deletion CLN1 reduces efficiency sporulation delays program Δcln1 Δxbp1 strain not further delayed. Thus, may be Xbp1's primary cells. We hypothesize plays role early must repressed, later stages promote efficient sporulation.