Dicer associates with chromatin to repress genome activity in Schizosaccharomyces pombe
Dicer associates with chromatin to repress genome activity in Schizosaccharomyces pombe
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DOI：
10.1038/nsmb.1935
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发表时间：
2011-01-01
影响因子：
16.8
通讯作者：
Buehler, Marc
中科院分区：
文献类型：
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作者：
Woolcock, Katrina J.;Gaidatzis, Dimos;Buehler, Marc
在裂殖酵母S.在粟酒裂殖酵母中，需要RNA干扰（RNAi）途径来产生介导着丝粒重复的异染色质沉默的小干扰RNA（siRNA）。在这里，我们证明了RNAi也可以抑制基因组元件而不是组成型异染色质。使用DNA腺嘌呤甲基转移酶鉴定（DamID），我们表明，RNAi蛋白Dcr 1和Rdp 1物理关联的一些常染色质基因，非编码RNA基因和反转录转座子长末端重复序列，这种协会是独立的Clr 4组蛋白甲基转移酶。RNAi与染色质的物理结合足以引发沉默反应，但不足以组装异染色质。在新鉴定的RNAi靶标处的沉默模式与先前提出的共转录基因沉默模型一致，并且与痕量的siRNA起作用。我们预计，类似的机制也可以在其他真核生物中运作。
In the fission yeast S. pombe, the RNA interference (RNAi) pathway is required to generate small interfering RNAs (siRNAs) that mediate heterochromatic silencing of centromeric repeats. Here, we demonstrate that RNAi also functions to repress genomic elements other than constitutive heterochromatin. Using DNA adenine methyltransferase identification (DamID), we show that the RNAi proteins Dcr1 and Rdp1 physically associate with some euchromatic genes, noncoding RNA genes and retrotransposon long terminal repeats, and that this association is independent of the Clr4 histone methyltransferase. Physical association of RNAi with chromatin is sufficient to trigger a silencing response but not to assemble heterochromatin. The mode of silencing at the newly identified RNAi targets is consistent with a co-transcriptional gene silencing model, as proposed earlier, and functions with trace amounts of siRNAs. We anticipate that similar mechanisms could also be operational in other eukaryotes.