The essential transcription factor Reb1p interacts with the CLB2 UAS outside of the G2/M control region.
The essential transcription factor Reb1p interacts with the CLB2 UAS outside of the G2/M control region.
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DOI：
10.1093/nar/gkg638
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发表时间：
2003-08
影响因子：
14.9
通讯作者：
Ceri E. Van Slyke;E. Grayhack
中科院分区：
文献类型：
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作者：
Ceri E. Van Slyke;E. Grayhack
CLB 2的调节对于酿酒酵母正常营养细胞周期的完成和氮剥夺后营养细胞周期的偏离都是重要的。细胞周期调控CLB 2在G2/M期的转录是由一组蛋白质引起的，包括Mcm 1 p、Fkh 2/1 p和Ndd 1 p，这些蛋白质与一组共调控基因共有的35 bp G2/M特异性序列相关。CLB 2转录受额外信号调节，包括氮水平、来自Clb 2-Cdc 28激酶的正反馈和渗透胁迫，但尚未鉴定出相应的调节序列和蛋白质。我们发现，必需的Reb 1转录因子以高亲和力与CLB 2上游的序列结合，该序列位于之前其他人认为参与调节表达的区域内，但位于已知G2/M特异性位点的上游。当位于Gal 4结合位点下游时，来自Reb 1 p位点周围区域的CLB 2序列阻断Gal 4蛋白的激活。由于Reb 1 p位点的突变消除了这种效应，我们认为Reb 1 p很可能在体内占据该位点。
Regulation of CLB2 is important both for completion of the normal vegetative cell cycle in Saccharomyces cerevisiae and for departure from the vegetative cell cycle upon nitrogen deprivation. Cell cycle-regulated transcription of CLB2 in the G2/M phase is known to be brought about by a set of proteins including Mcm1p, Fkh2/1p and Ndd1p that associate with a 35 bp G2/M-specific sequence common to a set of co-regulated genes. CLB2 transcription is regulated by additional signals, including by nitrogen levels, by positive feedback from the Clb2-Cdc28 kinase, and by osmotic stress, but the corresponding regulatory sequences and proteins have not been identified. We have found that the essential Reb1 transcription factor binds with high affinity to a sequence upstream of CLB2, within a region implicated previously by others in regulated expression, but upstream of the known G2/M-specific site. CLB2 sequence from the region around the Reb1p site blocks activation by the Gal4 protein when positioned downstream of the Gal4-binding site. Since a mutation in the Reb1p site abrogates this effect, we suggest that Reb1p is likely to occupy this site in vivo.