Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
Nat Plants. 2015 Jun 1;1:15075. doi: 10.1038/nplants.2015.75.
MicroRNAs (miRNAs) are a class of small non-coding RNAs that play important regulatory roles in gene expression in plants and animals. The biogenesis of miRNAs involves the transcription of primary miRNAs (pri-miRNAs) by RNA polymerase II (RNAPII) and subsequent processing by Dicer or Dicer-like (DCL) proteins. Here we show that the Elongator complex is involved in miRNA biogenesis in Arabidopsis. Disruption of Elongator reduces RNAPII occupancy at miRNA loci and pri-miRNA transcription. We also show that Elongator interacts with the DCL1-containing Dicing complex and lack of Elongator impairs DCL1 localization in the nuclear Dicing body. Finally, we show that pri-miRNA transcripts as well as DCL1 associate with the chromatin of miRNA genes and the chromatin association of DCL1 is compromised in the absence of Elongator. Our results suggest that Elongator functions in both transcription and processing of pri-miRNAs and probably couples these two processes.
微 RNA（miRNA）是一类小的非编码 RNA，在动植物基因表达中发挥重要的调控作用。miRNA 的生物发生涉及由 RNA 聚合酶 II（RNAPII）转录初级 miRNA（pri-miRNA），然后由 Dicer 或 Dicer 样（DCL）蛋白进行加工。在这里，我们表明 Elongator 复合物参与了拟南芥中 miRNA 的生物发生。Elongator 的破坏会降低 miRNA 基因座和 pri-miRNA 转录的 RNAPII 占有率。我们还表明，Elongator 与包含 DCL1 的 Dicing 复合物相互作用，并且缺乏 Elongator 会损害核 Dicing 体中 DCL1 的定位。最后，我们表明 pri-miRNA 转录本以及 DCL1 与 miRNA 基因的染色质相关联，并且在缺乏 Elongator 的情况下，DCL1 的染色质关联受到损害。我们的结果表明，Elongator 既参与 pri-miRNA 的转录，也参与其加工，可能将这两个过程偶联起来。
