B2 RNA binds directly to RNA polymerase II to repress transcript synthesis
B2 RNA binds directly to RNA polymerase II to repress transcript synthesis
复制标题
DOI：
10.1038/nsmb812
复制
发表时间：
2004-09-01
影响因子：
16.8
通讯作者：
Goodrich, JA
中科院分区：
文献类型：
--
作者：
Espinoza, CA;Allen, TA;Goodrich, JA
B2 RNA是一种小的非编码RNA聚合酶III转录物，在小鼠细胞中抑制mRNA转录以响应热休克。在这里，我们定义了B2 RNA抑制RNA聚合酶II（Pol II）转录的机制。使用纯化的Pol II转录系统，我们发现B2 RNA通过以高亲和力和特异性结合核心Pol II而有效地抑制转录。通过这种相互作用，B2 RNA在启动子处组装成前起始复合物并阻断RNA合成。一旦B2 RNA从起始前复合物中去除，转录活性就恢复了。我们的研究描述了一种以前未观察到的小RNA转录抑制机制，并表明B2 RNA与Pol II在热休克细胞的启动子处结合，以积极抑制转录。
B2 RNA is a small noncoding RNA polymerase III transcript that represses mRNA transcription in response to heat shock in mouse cells. Here we define the mechanism by which B2 RNA inhibits RNA polymerase II (Pol II) transcription. Using a purified Pol II transcription system, we found that B2 RNA potently inhibits transcription by binding to core Pol II with high affinity and specificity. Through this interaction, B2 RNA assembles into preinitiation complexes at the promoter and blocks RNA synthesis. Once B2 RNA is removed from preinitiation complexes, transcriptional activity is restored. Our studies describe a previously unobserved mechanism of transcriptional repression by a small RNA and suggest that B2 RNA associates with Pol II at promoters in heat shocked cells to actively inhibit transcription.