Department of Biochemistry, University of Hong Kong, Pokfulam, Hong Kong SAR, PR China.
Department of Pathology, School of Medicine, Xi'an Jiaotong University, Xi'an, PR China.
J Gen Virol. 2013 Dec;94(Pt 12):2739-2744. doi: 10.1099/vir.0.056226-0. Epub 2013 Sep 17.
Epstein-Barr virus (EBV) encodes at least 44 mature microRNAs (miRNAs), some of which are abundantly expressed in nasopharyngeal carcinoma cells. EBV-encoded miR-BART6 miRNA is known to undergo adenosine-to-inosine (A-to-I) RNA editing, which impacts on processing and function. Whether additional EBV miRNAs might be A-to-I edited remains to be determined. In this study, we have reported on A-to-I editing of EBV miR-BART3. The A-to-I editing enzyme was expressed abundantly in EBV-infected epithelial carcinoma cells. pri-miR-BART3 was found to be edited at four sites in these cells and in nasopharyngeal carcinoma samples. Whereas editing of the second site located within the seed region prevented the targeting of DICE1 mRNA, editing of the third site effectively crippled the biogenesis of mature miR-BART3. Thus, A-to-I editing perturbs biogenesis and targeting of miR-BART3 and may contribute to its differential expression and function in EBV-infected epithelial cells.
EBV 编码至少 44 种成熟的 microRNAs（miRNAs），其中一些在鼻咽癌细胞中大量表达。已知 EBV 编码的 miR-BART6 miRNA 经历腺苷到肌苷（A-to-I）RNA 编辑，这会影响加工和功能。是否有其他 EBV miRNAs 可能会发生 A-to-I 编辑还有待确定。在这项研究中，我们报道了 EBV miR-BART3 的 A-to-I 编辑。A-to-I 编辑酶在 EBV 感染的上皮癌细胞中大量表达。在这些细胞和鼻咽癌样本中发现 pri-miR-BART3 在四个位点发生了 A-to-I 编辑。虽然位于种子区域内的第二个位点的编辑阻止了 DICE1 mRNA 的靶向，但第三个位点的编辑有效地削弱了成熟 miR-BART3 的生物发生。因此，A-to-I 编辑扰乱了 miR-BART3 的生物发生和靶向，可能导致其在 EBV 感染的上皮细胞中的差异表达和功能。
