Chromatin-associated RNA interference components contribute to transcriptional regulation in Drosophila.
Chromatin-associated RNA interference components contribute to transcriptional regulation in Drosophila.
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DOI：
10.1038/nature10492
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发表时间：
2011-11-06
期刊：
影响因子：
64.8
通讯作者：
Orlando, Valerio
中科院分区：
文献类型：
--
作者：
Cernilogar, Filippo M.;Onorati, Maria Cristina;Kothe, Greg O.;Burroughs, A. Maxwell;Parsi, Krishna Mohan;Breiling, Achim;Lo Sardo, Federica;Saxena, Alka;Miyoshi, Keita;Siomi, Haruhiko;Siomi, Mikiko C.;Carninci, Piero;Gilmour, David S.;Corona, Davide F. V.;Orlando, Valerio
RNAi途径已经进化为基因表达的重要调节剂，其通过短（21- 30 nt）RNAs的活性降解RNA靶分子在细胞质中起作用。据报道，RNAi组分在细胞核中起作用，因为它们参与表观遗传调控和异染色质形成。然而，尽管RNAi介导的转录后沉默（PTGS）被充分记载，但RNAi介导的转录基因沉默（TGS）的机制，特别是RNAi组分在染色质中的作用，特别是在高等真核生物中，仍然是难以捉摸的。在这里，我们表明，关键的RNAi组件Dicer-2（Dcr 2）和Argonaute-2（AGO 2）AGO 2与染色质相关，对常染色质，转录活性位点有强烈的偏好，并与核心转录机制相互作用。值得注意的是，Dcr 2和AGO 2的功能丧失表明，转录缺陷伴随着启动子上Pol II定位的扰动。此外，Dcr 2和Ago 2无效突变以及损害RNAi活性的错义突变在热休克时损害全局Pol II动力学。最后，AGO 2 RIP-seq实验表明，AGO 2在正义和反义上都强烈富集于包括启动子以及热休克的其他部分和其他基因位点的小RNA中，尤其是在热休克后，对反义具有强烈的偏好。总之，我们的研究结果揭示了一个新的情况下，Dcr 2和AGO 2是全球性的转录活性位点，并可能发挥关键作用，通过控制RNA Pol II的持续合成能力塑造转录组。
RNAi pathways have evolved as important modulators of gene expression that act in the cytoplasm by degrading RNA target molecules via the activity of short (21-30nt) RNAs RNAi components have been reported to play a role in the nucleus as they are involved in epigenetic regulation and heterochromatin formation. However, although RNAi-mediated post-transcriptional silencing (PTGS) is well documented, mechanisms of RNAi-mediated transcriptional gene silencing (TGS) and in particular the role of RNAi components in chromatin, especially in higher eukaryotes, are still elusive. Here we show that key RNAi components Dicer-2 (Dcr2) and and Argonaute-2 (AGO2) AGO2 associate with chromatin, with strong preference for euchromatic, transcriptionally active loci and interact with core transcription machinery. Notably Dcr2 and AGO2 loss of function show that transcriptional defects are accompanied by perturbation of Pol II positioning on promoters. Further, both Dcr2 and Ago2 null mutations as well as missense mutations compromising the RNAi activity impair global Pol II dynamics upon heat shock. Finally, AGO2 RIP-seq experiments reveal that, AGO2 is strongly enriched in small-RNAs encompassing promoter as well as other parts of heat shock and other gene loci on both sense and antisense, with a strong bias for antisense, particularly after heat shock. Taken together our results reveal a new scenario in which Dcr2 and AGO2 are globally associated with transcriptionally active loci and may play a pivotal role in shaping the transcriptome by controlling RNA Pol II processivity.
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影响因子：
5.3
作者：
Lee, Chanhyo;Li, Xiaoyong;Gilmour, David S.
通讯作者：
Gilmour, David S.
影响因子：
16
作者：
Lupo, R;Breiling, A;Orlando, V
通讯作者：
Orlando, V
影响因子：
10.5
作者：
MESSMER, S;FRANKE, A;PARO, R
通讯作者：
PARO, R
影响因子：
64.5
作者：
Malone CD;Hannon GJ
通讯作者：
Hannon GJ
RNA聚合酶II和小的RNA机械的相互作用会影响果蝇中的异质沉默。
影响因子：
3.9
作者：
Kavi HH;Birchler JA
通讯作者：
Birchler JA