An oligomeric form of the large subunit of transcription factor (TF) IIE activates phosphorylation of the RNA polymerase II carboxyl-terminal domain by TFIIH.
An oligomeric form of the large subunit of transcription factor (TF) IIE activates phosphorylation of the RNA polymerase II carboxyl-terminal domain by TFIIH.
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发表时间：
1994-08
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通讯作者：
H. Serizawa;J. Conaway;R. Conaway
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作者：
H. Serizawa;J. Conaway;R. Conaway
RNA聚合酶II的最大亚基的羧基末端结构域（CTD）被一般转录因子IIH（TFIIH）磷酸化被认为在信使RNA合成的某个阶段控制聚合酶的活性。在最近的研究中，基于表明重组TFIIE制剂通过TFIIH强烈刺激CTD磷酸化的证据，提出转录因子IIE（TFIIE）在调节RNA聚合酶II CTD的磷酸化中起关键作用（Lu，H.，扎韦尔湖费希尔湖，Egly，J. - M.，Reinberg，D.（1992）Nature 358，641-645）。TFIIE是一种由56-kDa（p56）和34-kDa（p34）亚基组成的异二聚体，与TATA因子、TFIIB、TFIIF和TFIIH协同作用，促进RNA聚合酶II预起始复合物的形成。在研究TFIIE在控制RNA聚合酶II CTD磷酸化中的作用的过程中，我们发现重组TFIIE p56亚基的制备足以重建TFIIH激酶对CTD磷酸化的刺激。进一步的研究表明，CTD激酶刺激活性是色谱分离的大部分转录活性p56亚基，而不是与一个小的寡聚形式的p56。总之，这些发现表明，TFIIE p56亚基不仅能够与p34亚基相互作用，而且能够与自身相互作用，形成异二聚体或高分子量寡聚体，这些寡聚体在TFIIH激酶的转录起始和调节中发挥不同的作用。
Phosphorylation of the COOH-terminal domain (CTD) of the largest subunit of RNA polymerase II by general transcription factor IIH (TFIIH) is believed to control the activity of polymerase at some stage of messenger RNA synthesis. In a recent study, transcription factor IIE (TFIIE) was proposed to play a key role in regulating phosphorylation of the RNA polymerase II CTD, on the basis of evidence indicating that preparations of recombinant TFIIE strongly stimulate CTD phosphorylation by TFIIH (Lu, H., Zawel, L., Fischer, L., Egly, J.-M., and Reinberg, D. (1992) Nature 358, 641-645). TFIIE is a heterodimer composed of 56-kDa (p56) and 34-kDa (p34) subunits and functions in concert with the TATA factor, TFIIB, TFIIF, and TFIIH to promote formation of the RNA polymerase II preinitiation complex. In the process of investigating the role that TFIIE plays in controlling phosphorylation of the RNA polymerase II CTD, we discovered that preparations of the recombinant TFIIE p56 subunit were sufficient to reconstitute stimulation of CTD phosphorylation by the TFIIH kinase. Further investigation revealed that CTD kinase stimulatory activity was chromatographically separable from the bulk of the transcriptionally active p56 subunit and was associated, instead, with a minor oligomeric form of p56. Taken together, these findings argue that the TFIIE p56 subunit is capable of interacting not only with the p34 subunit but also with itself to form either heterodimers or high molecular mass oligomers that play distinct roles in transcription initiation and regulation of the TFIIH kinase.