Panoramix enforces piRNA-dependent cotranscriptional silencing.
Panoramix enforces piRNA-dependent cotranscriptional silencing.
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DOI：
10.1126/science.aab0700
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发表时间：
2015-10-16
期刊：
影响因子：
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通讯作者：
Hannon GJ
中科院分区：
文献类型：
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作者：
Yu Y;Gu J;Jin Y;Luo Y;Preall JB;Ma J;Czech B;Hannon GJ
Piwi相互作用RNA(PiRNA)途径是一种以RNA为基础的小的先天性免疫系统，它保护生殖细胞基因组免受转座子的攻击。在果蝇卵巢中，核Piwi蛋白是转录沉默转座子所必需的，尽管这发生的确切机制尚不清楚。在这里，我们证明CG9754蛋白是Piwi复合体的一个组成部分，该复合体在Piwi及其结合伙伴Asterix下游发挥转录沉默作用。CG9754强制拴在新生信使RNA转录本上会导致源基因座的共转录沉默和抑制染色质标记的沉积。我们将CG9754命名为“Panoramix”，我们认为这个蛋白质可以作为适配器，搭建piRNA途径和它招募的用于实施转录抑制的一般沉默机制之间的相互作用的支架。
The Piwi-interacting RNA (piRNA) pathway is a small RNA–based innate immune system that defends germ cell genomes against transposons. In Drosophila ovaries, the nuclear Piwi protein is required for transcriptional silencing of transposons, though the precise mechanisms by which this occurs are unknown. Here we show that the CG9754 protein is a component of Piwi complexes that functions downstream of Piwi and its binding partner, Asterix, in transcriptional silencing. Enforced tethering of CG9754 to nascent messenger RNA transcripts causes cotranscriptional silencing of the source locus and the deposition of repressive chromatin marks. We have named CG9754 “Panoramix,” and we propose that this protein could act as an adaptor, scaffolding interactions between the piRNA pathway and the general silencing machinery that it recruits to enforce transcriptional repression.