Specialized Rap1p/Gcr1p transcriptional activation through Gcr1p DNA contacts requires Gcr2p, as does hyperphosphorylation of Gcr1p.
Specialized Rap1p/Gcr1p transcriptional activation through Gcr1p DNA contacts requires Gcr2p, as does hyperphosphorylation of Gcr1p.
复制标题
通过 Gcr1p DNA 接触进行专门的 Rap1p/Gcr1p 转录激活需要 Gcr2p，Gcr1p 的过度磷酸化也是如此。
DOI：
10.1093/genetics/147.2.493
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发表时间：
1997
期刊：
影响因子：
3.3
通讯作者：
Santangelo,GM
中科院分区：
文献类型：
--
作者：
Zeng,X;Deminoff,SJ;Santangelo,GM
The multifunctional regulatory factor Rap1p ofSaccharomyces cerevisiaeaccomplishes one of its tasks, transcriptional activation, by complexing with Gcr1p. An unusual feature of this heteromeric complex is its apparent capacity to contact simultaneously two adjacent DNA elements (UASRPGand the CT box, bound specifically by Rap1p and Gcr1p, respectively). The complex can activate transcription through isolated UASRPGbut not CT elements. In promoters that contain both DNA signals its activity is enhanced, provided the helical spacing between the two elements is appropriate; this suggests that at least transient DNA loop formation is involved. We show here that this CT box-dependent augmentation of Rap1p/Gcr1p activation requires the presence of a third protein Gcr2p; the Gcr2–growth defect appears to result from a genome-wide loss of the CT box effect. Interestingly, a hyperphosphorylated form of Gcr1p disappears in Δgcr2cells but reappears if they harbor a doubly point-mutatedGCR1allele that bypasses the Gcr2–growth defect. Gcr2p therefore appears to induce a conformation change in Gcr1p and/or stimulate its hyperphosphorylation; one or both of these effects can be mimicked in the absence ofGCR2by mutation ofGCR1. This improved view of Rap1p/Gcr1p/Gcr2p function reveals a new aspect of eukaryotic gene regulation: modification of an upstream activator, accompanied by at least transient DNA loop formation, mediates its improved capacity to activate transcription.
