Processing of primary microRNAs by the Microprocessor complex
Processing of primary microRNAs by the Microprocessor complex
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DOI：
10.1038/nature03049
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发表时间：
2004-11-11
期刊：
影响因子：
64.8
通讯作者：
Hannon, GJ
中科院分区：
文献类型：
--
作者：
Denli, AM;Tops, BBJ;Hannon, GJ
成熟的microRNA（miRNAs）通过两步加工途径产生，产生类似于22个核苷酸的小RNA，在转录后水平调节基因表达（1）。初始切割由Drosha催化，Drosha是RNase III家族的核酸酶，其作用于细胞核中的初级miRNA转录物（pri-miRNA）（2）。在这里，我们表明，Drosha存在于一个多蛋白质复合物，微处理器，并开始的过程中解构复杂的组成部分。沿着Drosha，微处理器还包含Pasha（Drosha的配偶体），一种双链RNA结合蛋白。在果蝇细胞或秀丽隐杆线虫中抑制Pasha表达会干扰pri-miRNA加工，导致pri-miRNA的积累和成熟miRNA的减少。pash-1基因缺失或突变。线虫引起let-7报告基因的去阻遏，并出现与在检查具有Dicer（dcr-1）或Drosha（drsh-1）损伤的蠕虫时观察到的表型缺陷重叠的表型缺陷。综合考虑，这些结果表明Pasha在miRNA成熟和miRNA介导的基因调控中的作用。
Mature microRNAs (miRNAs) are generated via a two-step processing pathway to yield similar to22-nucleotide small RNAs that regulate gene expression at the post-transcriptional level(1). Initial cleavage is catalysed by Drosha, a nuclease of the RNase III family, which acts on primary miRNA transcripts (pri-miRNAs) in the nucleus(2). Here we show that Drosha exists in a multiprotein complex, the Microprocessor, and begin the process of deconstructing that complex into its constituent components. Along with Drosha, the Microprocessor also contains Pasha (partner of Drosha), a double-stranded RNA binding protein. Suppression of Pasha expression in Drosophila cells or Caenorhabditis elegans interferes with pri-miRNA processing, leading to an accumulation of pri-miRNAs and a reduction in mature miRNAs. Finally, depletion or mutation of pash-1 in C. elegans causes de-repression of a let-7 reporter and the appearance of phenotypic defects overlapping those observed upon examination of worms with lesions in Dicer (dcr-1) or Drosha (drsh-1). Considered together, these results indicate a role for Pasha in miRNA maturation and miRNA-mediated gene regulation.