TRANSCRIPTION FACTORS IIE AND IIH AND ATP HYDROLYSIS DIRECT PROMOTER CLEARANCE BY RNA-POLYMERASE-II
TRANSCRIPTION FACTORS IIE AND IIH AND ATP HYDROLYSIS DIRECT PROMOTER CLEARANCE BY RNA-POLYMERASE-II
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DOI：
10.1016/0092-8674(94)90242-9
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发表时间：
1994-04-08
期刊：
影响因子：
64.5
通讯作者：
TJIAN, R
中科院分区：
文献类型：
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作者：
GOODRICH, JA;TJIAN, R
使用定义的RNA聚合酶II（pol II）转录系统，我们研究了基础因子在转录周期离散阶段的作用（例如，起始，启动子清除和转录延伸）。失败的起始分析表明，tata结合蛋白、转录因子TFIIB和TFIIF以及pol II是在线性和超卷曲模板上形成功能性起始复合物的必要和充分条件。相比之下，TFIIE、TFIIH和ATP水解在线性模板的启动子清除过程中是额外需要的，而负超卷曲则避免了这些辅助因素的需要。此外，在拉伸期间不需要TFIIE， TFIIH和超卷曲。我们的研究结果表明，在启动子清除过程中，tfiih相关的解旋酶活性或超卷曲的作用，而不是开放复合物的形成。这些结果确立了流产起始是研究真核转录系统中功能性起始复合物形成的有用方法，并为研究真核转录周期不同阶段的调控提供了框架。
Using a defined RNA polymerase II(pol II) transcription system, we have investigated the roles of basal factors at discrete stages during the transcription cycle (e.g., initiation, promoter clearance, and transcript elongation). Abortive initiation assays revealed that TATA-binding protein, transcription factors TFIIB and TFIIF, and pol II were necessary and sufficient to form functional initiation complexes on both linear and supercoiled templates. By contrast, TFIIE, TFIIH, and ATP hydrolysis were additionally required during promoter clearance from linear templates, while negative supercoiling obviated the need for these auxiliary factors. Furthermore, TFIIE, TFIIH, and supercoiling were not required during elongation. Our results suggest a role for TFIIH-associated helicase activity or supercoiling during promoter clearance rather than open complex formation. These results establish abortive initiation as a useful assay for studying functional initiation complex formation in defined eukaryotic transcription systems and provide a framework for investigating regulation at different stages of the eukaryotic transcription cycle.