MicroRNA genes are transcribed by RNA polymerase II
MicroRNA genes are transcribed by RNA polymerase II
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DOI：
10.1038/sj.emboj.7600385
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发表时间：
2004-10-13
期刊：
影响因子：
11.4
通讯作者：
Kim, VN
中科院分区：
文献类型：
--
作者：
Lee, Y;Kim, M;Kim, VN
microRNA（miRNAs）是一类非编码RNA，在多种基因沉默途径中起着引导分子的作用。目前的工作重点是miRNA的调节功能，而对这些不寻常的基因本身如何调节知之甚少。在这里，我们提出了第一个直接的证据表明，miRNA基因是由RNA聚合酶II（pol II）转录。初级miRNA转录物（pri-miRNA）含有帽结构以及聚（A）尾，这是II类基因转录物的独特性质。用α-鹅膏蕈碱处理人细胞在选择性抑制pol II活性的浓度下降低了pri-miRNA的水平。此外，染色质免疫沉淀分析表明，pol II与miRNA启动子物理相关。我们还首次通过确定mir-23 asimilar to 27 asimilar to 24 -2的启动子和终止子来描述miRNA基因的详细结构。这些数据表明，pol II是主要的，如果不是唯一的，用于miRNA基因转录的RNA聚合酶。我们的研究为理解miRNA基因的结构和调控提供了基础。
MicroRNAs (miRNAs) constitute a large family of noncoding RNAs that function as guide molecules in diverse gene silencing pathways. Current efforts are focused on the regulatory function of miRNAs, while little is known about how these unusual genes themselves are regulated. Here we present the first direct evidence that miRNA genes are transcribed by RNA polymerase II (pol II). The primary miRNA transcripts (pri-miRNAs) contain cap structures as well as poly(A) tails, which are the unique properties of class II gene transcripts. The treatment of human cells with alpha-amanitin decreased the level of pri-miRNAs at a concentration that selectively inhibits pol II activity. Furthermore, chromatin immunoprecipitation analyses show that pol II is physically associated with a miRNA promoter. We also describe, for the first time, the detailed structure of a miRNA gene by determining the promoter and the terminator of mir-23asimilar to27asimilar to24-2. These data indicate that pol II is the main, if not the only, RNA polymerase for miRNA gene transcription. Our study offers a basis for understanding the structure and regulation of miRNA genes.