Gu W, Malik S, Ito M, Yuan C X, Fondell J D, Zhang X, Martinez E, Qin J, Roeder R G
Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021, USA.
Mol Cell. 1999 Jan;3(1):97-108. doi: 10.1016/s1097-2765(00)80178-1.
A novel human complex that can either repress activator-dependent transcription mediated by PC4, or, at limiting TFIIH, act synergistically with PC4 to enhance activator-dependent transcription has been purified. This complex contains homologs of a subset of yeast mediator/holoenzyme components (including SRB7, SRB10, SRB11, MED6, and RGR1), homologs of other yeast transcriptional regulatory factors (SOH1 and NUT2), and, significantly, some components (TRAP220, TRAP170/hRGR1, and TRAP100) of a human thyroid hormone receptor-associated coactivator complex. The complex shows direct activator interactions but, unlike yeast mediator, can act independently of the RNA polymerase II CTD. These findings demonstrate both positive and negative functional capabilities for the human complex, emphasize novel (CTD-independent) regulatory mechanisms, and link the complex to other human coactivator complexes.
一种新型人类复合物已被纯化，该复合物既可以抑制由PC4介导的激活因子依赖性转录，也可以在TFIIH有限的情况下与PC4协同作用，增强激活因子依赖性转录。这种复合物包含酵母中介体/全酶组分的一个子集的同源物（包括SRB7、SRB10、SRB11、MED6和RGR1）、其他酵母转录调节因子的同源物（SOH1和NUT2），并且值得注意的是，还包含人类甲状腺激素受体相关共激活因子复合物的一些组分（TRAP220、TRAP170/hRGR1和TRAP100）。该复合物显示出与激活因子的直接相互作用，但与酵母中介体不同的是，它可以独立于RNA聚合酶II CTD发挥作用。这些发现证明了该人类复合物具有正向和负向功能，强调了新的（不依赖CTD的）调节机制，并将该复合物与其他人类共激活因子复合物联系起来。
