阿拉比多普西斯的染色素修饰核siRNA路径涉及一个核细胞RNA处理中心
Olga Pontes1, Carey Fei Li, Pedro Costa Nunes
1Biology Department, Washington University, 1 Brookings Drive, St. Louis, MO 63130, USA.
Cell
|July 15, 2006
概括
小干扰RNAs (siRNAs) 在Arabidopsis中指导DNA甲基化. 关键蛋白质,包括RNA聚合酶IV (Pol IV),RNA依赖RNA聚合酶2 (RDR2) 和ARGONAUTE4 (AGO4),为此过程定位到特定的细胞区域.
科学领域:
- 植物分子生物学 植物分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 这是一种RNA干扰.
背景情况:
- 在Arabidopsis thaliana中,细胞酸甲基化对于沉默内源DNA重复至关重要.
- 这种表观遗传过程依赖于一个复杂的途径,涉及RNA聚合酶,Dicer样蛋白和Argonaute蛋白.
研究的目的:
- 研究参与siRNA指导的DNA甲基化中的关键蛋白质的亚细胞定位和作用顺序.
- 为了阐明RNA指导的DNA甲基化途径在Arabidopsis的空间组织.
主要方法:
- 免疫光显微镜可视化siRNAs和通路蛋白质的局部化.
- 分析突变物中的蛋白质错位化,以确定蛋白质作用的顺序.
主要成果:
- RNA依赖RNA聚合酶2 (RDR2),DICER-LIKE3 (DCL3),ARGONAUTE4 (AGO4) 和Pol IVb亚单元NRPD1b与核中的siRNAs进行同位.
- RNA聚合酶IVa (Pol IVa) 和DRD1定位在核的外部,在内源的重复位置.
- 在该途径中,Pol IVa在上游作用,其局部性取决于RNA.
结论:
- siRNA指导的甲基化途径涉及明显的空间分区,具有siRNA复合体的核处理中心.
- 聚IVa在目标位置启动转录,随后是siRNA产生和沉默复合体的组装.
- 这种空间组织对于在重复的DNA元素中保持异色状态至关重要.
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