Sun X, Zhang Y, Cho H, Rickert P, Lees E, Lane W, Reinberg D
Howard Hughes Medical Institute, Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635, USA.
Mol Cell. 1998 Aug;2(2):213-22. doi: 10.1016/s1097-2765(00)80131-8.
A complex that represses activated transcription and contains the human homologs of the yeast Srb7, Srb10, Srb11, Rgr1, and Med6 proteins was isolated. The complex is devoid of the Srb polypeptides previously shown to be components of the yeast Mediator complex that functions in transcriptional activation. The complex phosphorylates the CTD of RNA polymerase II (RNAPII) at residues other than those phosphorylated by the kinase of TFIIH. Moreover, the complex specifically interacts with RNAPII. The interaction is not mediated by the CTD of RNAPII, but is precluded by phosphorylation of the CTD. Our results indicate that the complex is a subcomplex of the human RNAPII holoenzyme. We suggest that the RNAPII holoenzyme is a transcriptional control panel, integrating and responding to specific signals to activate or repress transcription.
分离出一种抑制激活转录的复合物，其包含酵母Srb7、Srb10、Srb11、Rgr1和Med6蛋白的人类同源物。该复合物缺乏先前显示为在转录激活中起作用的酵母中介体复合物组分的Srb多肽。该复合物在RNA聚合酶II（RNAPII）的CTD上，于TFIIH激酶磷酸化位点以外的残基处进行磷酸化。此外，该复合物特异性地与RNAPII相互作用。这种相互作用不是由RNAPII的CTD介导的，而是被CTD的磷酸化所阻止。我们的结果表明，该复合物是人类RNAPII全酶的一个亚复合物。我们认为，RNAPII全酶是一个转录控制面板，整合并响应特定信号以激活或抑制转录。
