The RNA exosome promotes transcription termination of backtracked RNA polymerase II
The RNA exosome promotes transcription termination of backtracked RNA polymerase II
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DOI：
10.1038/nsmb.2893
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发表时间：
2014-10-01
影响因子：
16.8
通讯作者：
Bachand, Francois
中科院分区：
文献类型：
--
作者：
Lemay, Jean-Francois;Larochelle, Marc;Bachand, Francois
外泌体是一种RNA衰变复合物，它不断监测转录并促进有缺陷mRNA的转录后周转。然而，外泌体对核RNA的监视如何与转录协调仍然是未知的。在这里，我们表明，粟酒裂殖酵母的RNA外泌体可以通过终止与暂停和回溯RNA聚合酶II（RNAPII）相关的转录事件来靶向转录机制;这与外泌体专门作用于RNAPII释放的RNA的概念相反。我们的数据支持RNAPII回溯为核心外泌体提供游离RNA 3'端的机制，这导致转录终止伴随相关转录物的降解。这些发现揭示了一种共转录RNA监视机制，即外泌体终止转录可防止异常通读RNA的形成和邻近基因的转录干扰。
The exosome is an RNA-decay complex that constantly monitors transcription and contributes to post-transcriptional turnover of faulty mRNAs. Yet how nuclear RNA surveillance by the exosome is coordinated with transcription is still unknown. Here we show that the RNA exosome of Schizosaccharomyces pombe can target the transcription machinery by terminating transcription events associated with paused and backtracked RNA polymerase II (RNAPII); this is contrary to the notion that the exosome acts exclusively on RNAs that have been released by RNAPII. Our data support a mechanism by which RNAPII backtracking provides a free RNA 3' end for the core exosome, which results in transcription termination with concomitant degradation of the associated transcript. These findings uncover a mechanism of cotranscriptional RNA surveillance whereby termination of transcription by the exosome prevents formation of aberrant readthrough RNAs and transcriptional interference at neighboring genes.