Mmi1 RNA surveillance machinery directs RNAi complex RITS to specific meiotic genes in fission yeast
Mmi1 RNA surveillance machinery directs RNAi complex RITS to specific meiotic genes in fission yeast
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DOI：
10.1038/emboj.2012.105
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发表时间：
2012-05-16
期刊：
影响因子：
11.4
通讯作者：
Verdel, Andre
中科院分区：
文献类型：
--
作者：
Hiriart, Edwige;Vavasseur, Aurelia;Verdel, Andre
RNA干扰（RNAi）通过在转录和转录后水平上作用于广泛的真核生物来沉默基因表达。在裂殖酵母裂殖酵母中，RNA诱导的转录沉默（RITS）RNAi复合物介导非编码和重复DNA处的异染色质形成。然而，RITS在其他基因组区域（包括蛋白质编码基因）的靶向和作用仍然未知。在这里，我们表明，RITS定位于特定的减数分裂基因和mRNA。值得注意的是，RITS是由RNA结合蛋白Mmi 1及其相关的RNA监视机制引导到这些减数分裂靶点的，它们在营养生长期间一起降解选择性减数分裂mRNA。性分化后，RITS定位于减数分裂基因和mRNA的丢失。对Mmi 1 RNA靶点的大规模鉴定表明，RITS亚基Chp 1与其中绝大多数相关。此外，RNAi的丧失影响由Mmi 1 RNA监视机制介导的性分化的有效抑制。这些发现揭示了一种将RNAi招募到特定减数分裂基因的新机制，并表明RNAi参与了裂殖酵母性别分化的控制。The EMBO Journal（2012）31，2296-2308. doi：10.1038/emboj.2012.105;在线发布2012年4月20日
RNA interference (RNAi) silences gene expression by acting both at the transcriptional and post-transcriptional levels in a broad range of eukaryotes. In the fission yeast Schizosaccharomyces pombe the RNA-Induced Transcriptional Silencing (RITS) RNAi complex mediates heterochromatin formation at non-coding and repetitive DNA. However, the targeting and role of RITS at other genomic regions, including protein-coding genes, remain unknown. Here we show that RITS localizes to specific meiotic genes and mRNAs. Remarkably, RITS is guided to these meiotic targets by the RNA-binding protein Mmi1 and its associated RNA surveillance machinery that together degrade selective meiotic mRNAs during vegetative growth. Upon sexual differentiation, RITS localization to the meiotic genes and mRNAs is lost. Large-scale identification of Mmi1 RNA targets reveals that RITS subunit Chp1 associates with the vast majority of them. In addition, loss of RNAi affects the effective repression of sexual differentiation mediated by the Mmi1 RNA surveillance machinery. These findings uncover a new mechanism for recruiting RNAi to specific meiotic genes and suggest that RNAi participates in the control of sexual differentiation in fission yeast. The EMBO Journal (2012) 31, 2296-2308. doi: 10.1038/emboj.2012.105; Published online 20 April 2012