Egloff Sylvain, O'Reilly Dawn, Chapman Rob D, Taylor Alice, Tanzhaus Katrin, Pitts Laura, Eick Dirk, Murphy Shona
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
Science. 2007 Dec 14;318(5857):1777-9. doi: 10.1126/science.1145989.
RNA polymerase II (Pol II) transcribes genes that encode proteins and noncoding small nuclear RNAs (snRNAs). The carboxyl-terminal repeat domain (CTD) of the largest subunit of mammalian RNA Pol II, comprising tandem repeats of the heptapeptide consensus Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7, is required for expression of both gene types. We show that mutation of serine-7 to alanine causes a specific defect in snRNA gene expression. We also present evidence that phosphorylation of serine-7 facilitates interaction with the snRNA gene-specific Integrator complex. These findings assign a biological function to this amino acid and highlight a gene type-specific requirement for a residue within the CTD heptapeptide, supporting the existence of a CTD code.
RNA聚合酶II（Pol II）转录编码蛋白质和非编码小核RNA（snRNA）的基因。哺乳动物RNA Pol II最大亚基的羧基末端重复结构域（CTD）由七肽共有序列Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7的串联重复组成，这两种基因类型的表达都需要它。我们发现，丝氨酸7突变为丙氨酸会导致snRNA基因表达出现特定缺陷。我们还提供证据表明，丝氨酸7的磷酸化促进了与snRNA基因特异性整合复合物的相互作用。这些发现赋予了这个氨基酸一种生物学功能，并突出了CTD七肽内一个残基对基因类型的特异性需求，支持了CTD编码的存在。
