一个前体一个siRNA模型用于Pol IV-依赖siRNA生物发生
Jixian Zhai1, Sylvain Bischof1, Haifeng Wang2
1Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA.
Cell
|October 10, 2015
概括
植物RNA聚合酶IV (Pol IV) 产生短RNA前体 (P4RNAs),在阿拉比多普西斯中产生单个24-n小干扰RNAs (siRNAs),揭示了RNA导向DNA甲基化的新机制.
科学领域:
- 植物分子生物学
- 表观遗传学
- RNA生物学
背景情况:
- 通过RNA导向的DNA甲基化对于植物的基因沉默至关重要.
- 植物特异性RNA聚合酶IV (Pol IV) 启动了这一过程.
- 现有的模型建议Pol IV转录产生多个siRNA.
研究的目的:
- 调查Pol IV依赖RNAs (P4RNAs) 的精确性质和生物发生.
- 阐明P4RNAs与24-nt siRNA产生之间的关系.
- 了解Arabidopsis thaliana中RNA导向的DNA甲基化的机制.
主要方法:
- 在野生类型的阿拉比多普西斯中分析Pol IV依赖RNA (P4RNAs).
- P4RNA长度,分布,丰度和链偏差的表征.
- 研究P4RNA的5'和3'端修饰,包括核酸错误结合.
主要成果:
- 在关键特征上,P4RNAs是意想不到的短 (30-40 nt) 和24 nt siRNAs非常相似.
- P4RNA具有5'-单酸盐,并表现出3'-错误结合的核酸.
- 3'-错误整合与细胞因子的DNA甲基化相关,表明共转录反.
结论:
- 波尔IV转录产生短P4RNA,挑战多siRNA前体模型.
- 一个"一个前体,一个siRNA"模型被提议用于24-nt siRNA生物发生.
- 通过协同转录反机制,DNA甲基化增强了siRNA的产生.
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