Transduction of RNA-directed DNA methylation signals to repressive histone marks in Arabidopsis thaliana
Transduction of RNA-directed DNA methylation signals to repressive histone marks in Arabidopsis thaliana
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DOI：
10.1038/emboj.2009.374
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发表时间：
2010-01-20
期刊：
影响因子：
11.4
通讯作者：
Habu, Yoshiki
中科院分区：
文献类型：
--
作者：
Numa, Hisataka;Kim, Jong-Myong;Habu, Yoshiki
rna定向修饰组蛋白对于高等真核生物异染色质的维持至关重要。在植物中，胞嘧啶甲基化是调节失活染色质的另一个因素，但胞嘧啶甲基化和抑制性组蛋白修饰共存的调节机制尚不清楚。本研究分析了拟南芥MORPHEUS' MOLECULE1 （MOM1）介导的基因沉默机制。转录分析显示，mom1中大多数上调的位点携带与转座子相关的序列，并且与野生型植物中积累的24-nt sirna同源，这些sirna是rna定向DNA甲基化（RdDM）的标志。对单拷贝基因SUPPRESSOR of drm1 drm2 cmt3 （SDC）的分析显示，mom1激活SDC，同时在启动子区域串联重复序列上减少二甲基化组蛋白H3赖氨酸9 (H3K9me2)，而不改变siRNA积累和胞嘧啶甲基化。H3K9me2的减少在串联重复序列的侧翼区域没有观察到。结果表明，MOM1将RdDM信号转导到RdDM核心区域抑制组蛋白修饰。EMBO杂志（2010）29,352-362。doi: 10.1038 / emboj.2009.374;2009年12月10日在线发布
RNA-directed modification of histones is essential for the maintenance of heterochromatin in higher eukaryotes. In plants, cytosine methylation is an additional factor regulating inactive chromatin, but the mechanisms regulating the coexistence of cytosine methylation and repressive histone modification remain obscure. In this study, we analysed the mechanism of gene silencing mediated by MORPHEUS' MOLECULE1 (MOM1) of Arabidopsis thaliana. Transcript profiling revealed that the majority of up-regulated loci in mom1 carry sequences related to transposons and homologous to the 24-nt siRNAs accumulated in wild-type plants that are the hallmarks of RNA-directed DNA methylation (RdDM). Analysis of a single-copy gene, SUPPRESSOR OF drm1 drm2 cmt3 (SDC), revealed that mom1 activates SDC with concomitant reduction of di-methylated histone H3 lysine 9 (H3K9me2) at the tandem repeats in the promoter region without changes in siRNA accumulation and cytosine methylation. The reduction of H3K9me2 is not observed in regions flanking the tandem repeats. The results suggest that MOM1 transduces RdDM signals to repressive histone modification in the core region of RdDM. The EMBO Journal (2010) 29, 352-362. doi: 10.1038/emboj.2009.374; Published online 10 December 2009