Sub1 Globally Regulates RNA Polymerase II C-Terminal Domain Phosphorylation
Sub1 Globally Regulates RNA Polymerase II C-Terminal Domain Phosphorylation
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DOI：
10.1128/mcb.00819-10
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发表时间：
2010-11-01
影响因子：
5.3
通讯作者：
Calvo, Olga
中科院分区：
文献类型：
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作者：
Garcia, Alicia;Rosonina, Emanuel;Calvo, Olga
转录辅活化子Sub1参与了酵母中mRNA代谢的几个方面，如转录的激活、终止和3‘端的形成。在这里，我们提出的证据是，Sub1在控制RNA聚合酶II大亚基C末端结构域(CTD)的磷酸化方面发挥着重要作用。我们发现SUB1与编码所有四个已知的CTD激酶SRB10、KIN28、BUR1和CTK1的基因在遗传上相互作用，这表明Sub1在转录周期的多个步骤中影响CTD的磷酸化。为了直接解决这一问题，我们首先使用了体外激酶分析，我们发现，一方面，SUB1缺失增加了Kin28、Bur1和Ctk1对CTD的磷酸化，但另一方面，它降低了Srb10对CTD的磷酸化。其次，染色质免疫沉淀分析显示，SUB1缺失降低了诱导性GAL1基因上的Srb10染色质结合，而增加了激活转录基因上的Kin28和Ctk1染色质结合。综上所述，我们的数据表明Sub1在整个转录周期中对CTD磷酸化的调节具有多种作用。
The transcriptional coactivator Sub1 has been implicated in several aspects of mRNA metabolism in yeast, such as activation of transcription, termination, and 3'-end formation. Here, we present evidence that Sub1 plays a significant role in controlling phosphorylation of the RNA polymerase II large subunit C-terminal domain (CTD). We show that SUB1 genetically interacts with the genes encoding all four known CTD kinases, SRB10, KIN28, BUR1, and CTK1, suggesting that Sub1 acts to influence CTD phosphorylation at more than one step of the transcription cycle. To address this directly, we first used in vitro kinase assays, and we show that, on the one hand, SUB1 deletion increased CTD phosphorylation by Kin28, Bur1, and Ctk1 but, on the other, it decreased CTD phosphorylation by Srb10. Second, chromatin immunoprecipitation assays revealed that SUB1 deletion decreased Srb10 chromatin association on the inducible GAL1 gene but increased Kin28 and Ctk1 chromatin association on actively transcribed genes. Taken together, our data point to multiple roles for Sub1 in the regulation of CTD phosphorylation throughout the transcription cycle.