Genome-wide location analysis reveals a role of TFIIS in RNA polymerase III transcription
Genome-wide location analysis reveals a role of TFIIS in RNA polymerase III transcription
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DOI：
10.1101/gad.471908
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发表时间：
2008-07-15
影响因子：
10.5
通讯作者：
Soutourina, Julie
中科院分区：
文献类型：
--
作者：
Ghavi-Helm, Yad;Michaut, Magali;Soutourina, Julie
TFIIS 是一种转录延伸因子，可刺激停滞的 RNA 聚合酶 II (Pol II) 的转录裂解活性。最近的研究表明，TFIIS 在 Pol II 转录起始中也发挥着作用。为了加深我们对 TFIIS 体内功能的理解，我们对该因子进行了全基因组定位分析。在正常生长条件下，在 Pol II 转录基因上检测到 TFIIS，并且 TFIIS 占用与 Pol II 的占用密切相关，表明 TFIIS 募集并不限于 NTP 耗尽的细胞。出乎意料的是，几乎所有 Pol III 转录基因上也检测到了 TFIIS。 TFIIS 和 Pol III 占据在此类新型靶标上在全基因组范围内具有良好的相关性。在体内，一些 dst1 突变体在 tRNA 合成方面存在部分缺陷，并且在限制温度下表现出 Pol III 占用率降低。体外转录测定表明 TFIIS 可能影响 Pol III 起始位点选择。这些数据提供了强有力的体内和体外证据，支持 TFIIS 作为通用 Pol III 转录因子的作用。
TFIIS is a transcription elongation factor that stimulates transcript cleavage activity of arrested RNA polymerase II (Pol II). Recent studies revealed that TFIIS has also a role in Pol II transcription initiation. To improve our understanding of TFIIS function in vivo, we performed genome-wide location analysis of this factor. Under normal growth conditions, TFIIS was detected on Pol II-transcribed genes, and TFIIS occupancy was well correlated with that of Pol II, indicating that TFIIS recruitment is not restricted to NTP-depleted cells. Unexpectedly, TFIIS was also detected on almost all Pol III-transcribed genes. TFIIS and Pol III occupancies correlated well genome-wide on this novel class of targets. In vivo, some dst1 mutants were partly defective in tRNA synthesis and showed a reduced Pol III occupancy at the restrictive temperature. In vitro transcription assays suggested that TFIIS may affect Pol III start site selection. These data provide strong in vivo and in vitro evidence in favor of a role of TFIIS as a general Pol III transcription factor.