Role for a bidentate ribonuclease in the initiation step of RNA interference
Role for a bidentate ribonuclease in the initiation step of RNA interference
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DOI：
10.1038/35053110
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发表时间：
2001-01-18
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：
Bernstein, E;Caudy, AA;Hannon, GJ
RNA干扰（RNAi）是双链RNA使同源基因沉默的机制（1-5）。在植物中，这可以发生在转录和转录后水平（1，2，5）;然而，在动物中，迄今为止仅报道了转录后RNAi。在植物和动物中，RNAi的特征在于存在与被抑制的基因同源的长度约22个核苷酸的RNA（6-8）。这些22个核苷酸序列作为指导序列，指导多组分核酸酶RISC破坏特定的信使RNA 6。在这里，我们确定了一种酶，切丁酶，它可以产生推定的指导RNA。Dicer是特异性切割双链RNA的核酸酶的RNase III家族的成员，并且在蠕虫、苍蝇、植物、真菌和哺乳动物中进化保守。该酶具有独特的结构，包括解旋酶结构域和双RNase III基序。Dicer还含有与RDE 1/QDE 2/ARGONAUTE家族同源的区域，该区域与RNAi遗传连锁（9，10）。
RNA interference (RNAi) is the mechanism through which double-stranded RNAs silence cognate genes(1-5). In plants, this can occur at both the transcriptional and the post-transcriptional levels(1,2,5); however, in animals, only post-transcriptional RNAi has been reported to date. In both plants and animals, RNAi is characterized by the presence of RNAs of about 22 nucleotides in length that are homologous to the gene that is being suppressed(6-8). These 22-nucleotide sequences serve as guide sequences that instruct a multicomponent nuclease, RISC, to destroy specific messenger RNAs6. Here we identify an enzyme, Dicer, which can produce putative guide RNAs. Dicer is a member of the RNase III family of nucleases that specifically cleave double-stranded RNAs, and is evolutionarily conserved in worms, flies, plants, fungi and mammals. The enzyme has a distinctive structure, which includes a helicase domain and dual RNase III motifs. Dicer also contains a region of homology to the RDE1/QDE2/ARGONAUTE family that has been genetically linked to RNAi(9,10).