Laboratory of RNA Editing, Onco-haematology Department, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, Rome 00165, Italy.
Int J Mol Sci. 2013 Nov 19;14(11):22796-816. doi: 10.3390/ijms141122796.
Adenosine deaminase acting on RNA (ADAR) enzymes convert adenosine (A) to inosine (I) in double-stranded (ds) RNAs. Since Inosine is read as Guanosine, the biological consequence of ADAR enzyme activity is an A/G conversion within RNA molecules. A-to-I editing events can occur on both coding and non-coding RNAs, including microRNAs (miRNAs), which are small regulatory RNAs of ~20-23 nucleotides that regulate several cell processes by annealing to target mRNAs and inhibiting their translation. Both miRNA precursors and mature miRNAs undergo A-to-I RNA editing, affecting the miRNA maturation process and activity. ADARs can also edit 3' UTR of mRNAs, further increasing the interplay between mRNA targets and miRNAs. In this review, we provide a general overview of the ADAR enzymes and their mechanisms of action as well as miRNA processing and function. We then review the more recent findings about the impact of ADAR-mediated activity on the miRNA pathway in terms of biogenesis, target recognition, and gene expression regulation.
腺苷脱氨酶作用于 RNA（ADAR）酶将双链 (ds) RNA 中的腺苷 (A) 转化为肌苷 (I)。由于肌苷被读为鸟苷，ADAR 酶活性的生物学后果是 RNA 分子内的 A/G 转换。A 到 I 的编辑事件可以发生在编码和非编码 RNA 上，包括 microRNAs (miRNAs)，它们是约 20-23 个核苷酸的小调节 RNA，通过与靶 mRNA 退火并抑制其翻译来调节几个细胞过程。miRNA 前体和成熟的 miRNA 都经历 A 到 I 的 RNA 编辑，影响 miRNA 的成熟过程和活性。ADAR 还可以编辑 mRNA 的 3'UTR，进一步增加 mRNA 靶标和 miRNA 之间的相互作用。在这篇综述中，我们提供了 ADAR 酶及其作用机制以及 miRNA 加工和功能的概述。然后，我们回顾了最近关于 ADAR 介导的活性对 miRNA 通路在生物发生、靶标识别和基因表达调控方面的影响的发现。
