Conditional expression of RNA polymerase II in mammalian cells - Deletion of the carboxyl-terminal domain of the large subunit affects early steps in transcription
Conditional expression of RNA polymerase II in mammalian cells - Deletion of the carboxyl-terminal domain of the large subunit affects early steps in transcription
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DOI：
10.1074/jbc.m001883200
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发表时间：
2000-08-11
影响因子：
4.8
通讯作者：
Eick, D
中科院分区：
文献类型：
--
作者：
Meininghaus, M;Chapman, RD;Eick, D
哺乳动物 RNA 聚合酶 II 大亚基的羧基末端结构域 (CTD) 包含 52 个七肽重复序列，该七肽是多种激酶的靶标。过度磷酸化的 CTD 募集 mRNA 加帽、剪接和 3'-加工的重要因子。然而，CTD 在体内转录过程中的作用尚不清楚。我们在 B 细胞中条件性表达了 α-鹅膏菌素抗性大亚基，其 CTD (LS*Delta 5) 几乎完全缺失。这些细胞在 α-鹅膏菌素存在的情况下，细胞基因的整体转录存在缺陷。此外，携带 LS*Delta 5 的 pol II 未能转录至 hsp70A 和 c-fos 基因启动子中的启动子近端暂停位点。结果表明，CTD 是 mRNA 启动子近端暂停和成熟之前发生的步骤所必需的。
The carboxyl-terminal domain (CTD) of the large subunit of mammalian RNA polymerase II contains 52 repeats of a heptapeptide that is the target of a variety of kinases, The hyperphosphorylated CTD recruits important factors for mRNA capping, splicing, and 3'-processing. The role of the CTD for the transcription process in vivo, however, is not yet clear. We have conditionally expressed an alpha-amanitin-resistant large subunit with an almost entirely deleted CTD (LS*Delta 5) in B-cells, These cells have a defect in global transcription of cellular genes in the presence of a-amanitin. Moreover, pol II harboring LS*Delta 5 failed to transcribe up to the promoter-proximal pause sites in the hsp70A and c-fos gene promoters. The results indicate that the CTD is already required for steps that occur before promoter-proximal pausing and maturation of mRNA.