Lau Nelson C, Seto Anita G, Kim Jinkuk, Kuramochi-Miyagawa Satomi, Nakano Toru, Bartel David P, Kingston Robert E
Department of Molecular Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.
Science. 2006 Jul 21;313(5785):363-7. doi: 10.1126/science.1130164. Epub 2006 Jun 15.
Small noncoding RNAs regulate processes essential for cell growth and development, including mRNA degradation, translational repression, and transcriptional gene silencing (TGS). During a search for candidate mammalian factors for TGS, we purified a complex that contains small RNAs and Riwi, the rat homolog to human Piwi. The RNAs, frequently 29 to 30 nucleotides in length, are called Piwi-interacting RNAs (piRNAs), 94% of which map to 100 defined (< or = 101 kb) genomic regions. Within these regions, the piRNAs generally distribute across only one genomic strand or distribute on two strands but in a divergent, nonoverlapping manner. Preparations of piRNA complex (piRC) contain rRecQ1, which is homologous to qde-3 from Neurospora, a gene implicated in silencing pathways. Piwi has been genetically linked to TGS in flies, and slicer activity cofractionates with the purified complex. These results are consistent with a gene-silencing role for piRC in mammals.
小非编码RNA调控细胞生长和发育所必需的过程，包括mRNA降解、翻译抑制和转录基因沉默（TGS）。在寻找TGS的候选哺乳动物因子的过程中，我们纯化了一种复合物，它包含小RNA和Riwi，即大鼠与人Piwi的同源物。这些RNA长度通常为29至30个核苷酸，被称为Piwi相互作用RNA（piRNA），其中94%定位于100个定义的（≤101 kb）基因组区域。在这些区域内，piRNA通常仅分布在一条基因组链上，或者分布在两条链上，但以发散、不重叠的方式分布。piRNA复合物（piRC）的制备物含有rRecQ1，它与粗糙脉孢菌的qde-3同源，qde-3是一个与沉默途径有关的基因。在果蝇中，Piwi在遗传上与TGS相关联，并且切割活性与纯化的复合物共分级分离。这些结果与piRC在哺乳动物中的基因沉默作用一致。
