Growth-related changes in phosphorylation of yeast RNA polymerase II
Growth-related changes in phosphorylation of yeast RNA polymerase II
复制标题
DOI：
10.1074/jbc.273.8.4689
复制
发表时间：
1998-02-20
影响因子：
4.8
通讯作者：
Corden, JL
中科院分区：
文献类型：
--
作者：
Patturajan, M;Schulte, RJ;Corden, JL
RNA聚合酶II的最大亚基含有独特的C末端结构域（CTD），其由共有七肽序列Tyr（1）-Ser（2）-Pro（3）-Thr（4）-Ser（5）Pro（6）-Ser（7）的串联重复组成。SDS-聚丙烯酰胺凝胶电泳可分离两种形式的最大亚基。称为IIA的较快迁移形式在CTD上含有很少或不含磷酸盐，而较慢迁移的II 0形式被多次磷酸化。具有不同磷酰基受体特异性的CTD激酶能够在体外将IIA转化为II 0，并且已经在体内鉴定了不同的磷酸异构体。在本文中，我们报告了一组单克隆抗体，识别不同的磷酸化表位的CTD的结合特异性。单克隆抗体如H5识别2位的磷酸丝氨酸，而单克隆抗体如H14识别5位的磷酸丝氨酸。当生长的酵母进入稳定期或热休克时，这些磷酸化表位的相对丰度发生变化。这些结果表明，不同的CTD磷酸受体位点的磷酸化独立调节响应于环境信号。
The largest subunit of RNA polymerase II contains a unique C-terminal domain (CTD) consisting of tandem repeats of the consensus heptapeptide sequence Tyr(1)-Ser(2)-Pro(3)-Thr(4)-Ser(5)Pro(6)-Ser(7). Two forms of the largest subunit can be separated by SDS-polyacrylamide gel electrophoresis. The faster migrating form termed IIA contains little or no phosphate on the CTD, whereas the slower migrating II0 form is multiply phosphorylated. CTD kinases with different phosphoryl acceptor specificities are able to convert IIA to II0 in vitro, and different phosphoisomers have been identified in vivo. In this paper we report the binding specificities of a set of monoclonal antibodies that recognize different phosphoepitopes on the CTD. Monoclonal antibodies like H5 recognize phosphoserine in position 2, whereas monoclonal antibodies like H14 recognize phosphoserine in position 5. The relative abundance of these phosphoepitopes changes when growing yeast enter stationary phase or are heat-shocked. These results indicate that phosphorylation of different CTD phosphoacceptor sites are independently regulated in response to environmental signals.