Song C Z
Institute for Molecular Virology, Saint Louis University School of Medicine, 3681 Park Avenue, St. Louis, Missouri, 63110, USA.
Biochem Biophys Res Commun. 1996 Dec 24;229(3):810-6. doi: 10.1006/bbrc.1996.1885.
RNA polymerase II exists in both phosphorylated and nonphosphorylated forms. The interconversion between these two forms is suggested to be the molecular switch that regulates the transition from transcription initiation to elongation. Here, the ATP analogue H8 is used as a CTD kinase inhibitor to study the role of CTD phosphorylation in transcription with a HeLa nuclear extract in vitro. The results demonstrate that (i) CTD phosphorylation is not required for transcription of the promoter proximal region from TATA containing promoters, (ii) the primary role of CTD phosphorylation is to promote productive elongation, and (iii) the contribution of CTD phosphorylation to transcription differs among TATA containing promoters as well as between TATA less and TATA containing promoters.
RNA聚合酶II以磷酸化和非磷酸化两种形式存在。这两种形式之间的相互转换被认为是调节从转录起始到延伸转变的分子开关。在此，ATP类似物H8用作CTD激酶抑制剂，以在体外利用HeLa细胞核提取物研究CTD磷酸化在转录中的作用。结果表明：（i）从含TATA的启动子转录启动子近端区域不需要CTD磷酸化；（ii）CTD磷酸化的主要作用是促进有效的延伸；（iii）CTD磷酸化对转录的贡献在含TATA的启动子之间以及在不含TATA和含TATA的启动子之间存在差异。
