mRNA capping enzyme is recruited to the transcription complex by phosphorylation of the RNA polymerase II carboxy-terminal domain
mRNA capping enzyme is recruited to the transcription complex by phosphorylation of the RNA polymerase II carboxy-terminal domain
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DOI：
10.1101/gad.11.24.3319
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发表时间：
1997-12-15
影响因子：
10.5
通讯作者：
Buratowski, S
中科院分区：
文献类型：
--
作者：
Cho, EJ;Takagi, T;Buratowski, S
MRNA的封顶发生在转录启动后不久，在其他mRNA处理事件之前，如mRNA剪接和聚腺苷酸化。为了确定转录和封顶之间的耦合机制，我们测试了封端酶和转录机制之间的物理相互作用。封闭酶与基础转录因子或RNA聚合酶II(POL II)全酶不稳定相关。然而，封闭酶可以直接和特异性地与RNA聚合酶羧基末端结构域(CTD)的磷酸化形式相互作用。这种关联发生在转录起始复合体的背景下，并被CTD-激酶抑制剂H8阻断。此外，POL II CTD的条件截断突变体与封闭酶突变体结合时是致命的。我们的结果提供了体外和体内证据，证明封闭酶是通过RNA聚合酶CTD的磷酸化被招募到转录复合体中的。
Capping of mRNA occurs shortly after transcription initiation, preceding other mRNA processing events such as mRNA splicing and polyadenylation. To determine the mechanism of coupling between transcription and capping, we tested for a physical interaction between capping enzyme and the transcription machinery. Capping enzyme is not stably associated with basal transcription factors or the RNA polymerase II (Pol II) holoenzyme. However, capping enzyme can directly and specifically interact with the phosphorylated form of the RNA polymerase carboxy-terminal domain (CTD). This association occurs in the context of the transcription initiation complex and is blocked by the CTD-kinase inhibitor H8. furthermore, conditional truncation mutants of the Pol II CTD are lethal when combined with a capping enzyme mutant. Our results provide in vitro and in vivo evidence that capping enzyme is recruited to the transcription complex via phosphorylation of the RNA polymerase CTD.