Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, CA 90095, USA.
Department of Biology, Southern University of Science and Technology, Shenzhen 518055, China.
J Genet Genomics. 2017 Jan 20;44(1):3-6. doi: 10.1016/j.jgg.2016.10.009. Epub 2016 Dec 30.
RNAi is a highly conserved machinery in eukaryotes for transcriptional or post-transcriptional silencing. In plants, RNA-directed DNA Methylation (RdDM) pathway deploys small interfering RNAs (siRNAs) to target DNA methylation. This process is initiated by the plant-specific RNA polymerase IV (Pol IV) to produce RNA precursors that are later processed into siRNAs. Until recently, characterization of Pol IV transcript had been difficult due to its presumed rapid turnover. This review summarizes five recent reports on Pol IV-dependent RNAs that explore the biogenesis and features of Pol IV transcripts, as well as alternative dicer-independent processing of Pol IV products.
RNAi 是真核生物中用于转录或转录后沉默的高度保守机制。在植物中，RNA 指导的 DNA 甲基化 (RdDM) 途径利用小干扰 RNA(siRNA) 靶向 DNA 甲基化。这一过程由植物特异性 RNA 聚合酶 IV (Pol IV) 启动，产生 RNA 前体，然后进一步加工成 siRNA。直到最近，由于假定的快速周转，Pol IV 转录本的特征描述一直很困难。这篇综述总结了最近关于 Pol IV 依赖性 RNA 的五个报告，探讨了 Pol IV 转录本的生物发生和特征，以及 Pol IV 产物的替代非依赖于 dicer 的加工。
