The diverse roles of RNA helicases in RNAi
The diverse roles of RNA helicases in RNAi
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DOI：
10.4161/cc.8.21.9887
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发表时间：
2009-11-01
期刊：
影响因子：
4.3
通讯作者：
Frolov, Maxim V.
中科院分区：
文献类型：
--
作者：
Ambrus, Aaron M.;Frolov, Maxim V.
RNA干扰（RNAi）是一种存在于几乎所有真核生物中的调控基因沉默系统，其利用通常20-25个核苷酸长的小RNA靶向mRNA中发现的互补序列。RNA解旋酶使用ATP解链双链RNA（dsRNA），并且已知参与RNA代谢的几乎每个水平。大量的RNA解旋酶已经从筛选必需的RNAi因子中分离出来，甚至RNAi途径的最早模型也假定RNA解旋酶在小RNA双链体解旋的水平上起作用。然而，尽管已经发现并表征了在RNAi中起作用的许多组分，但RNAi中RNA解旋酶在途径中的确切位置和特定生化功能的归属仍然难以捉摸。最近的研究已经深入到一些RNA解旋酶的确切作用。令人惊讶的是，这些研究揭示了非传统的作用，甚至可能不需要解旋酶的活性。这些发现表明，RNA解旋酶几乎在RNAi途径的每个水平上调节基因沉默。
RNA interference (RNAi) is a regulatory gene silencing system found in nearly all eukaryotic organisms that employs small RNAs, typically 20-25 nucleotides long, to target complementary sequences found in mRNAs. RNA helicases use ATP to unwind double-stranded RNA (dsRNA), and are known to participate at nearly every level of RNA metabolism. A multitude of RNA helicases have been isolated from screens for essential RNAi factors, and even the earliest models of the RNAi pathway have presumed an RNA helicase to function at the level of small RNA duplex unwinding. However, while many components that function in RNAi have been uncovered and characterized, the exact placement in the pathway and ascription of a specific biochemical function of an RNA helicase in RNAi remains elusive. Recent studies have delved deeper into the precise role of some RNA helicases. Surprisingly, these studies have revealed nontraditional roles, which may not even require the helicase activity. Such findings suggest that RNA helicases regulate gene silencing at nearly every level of the RNAi pathways.