Base Pairing between Hepatitis C Virus RNA and MicroRNA 122 3′ of Its Seed Sequence Is Essential for Genome Stabilization and Production of Infectious Virus
Base Pairing between Hepatitis C Virus RNA and MicroRNA 122 3′ of Its Seed Sequence Is Essential for Genome Stabilization and Production of Infectious Virus
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DOI：
10.1128/jvi.00513-12
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发表时间：
2012-07-01
影响因子：
5.4
通讯作者：
Lemon, Stanley M.
中科院分区：
文献类型：
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作者：
Shimakami, Tetsuro;Yamane, Daisuke;Lemon, Stanley M.
MicroRNA 122（miR-122）通过将含有argonaute 2（Ago 2）的RNA诱导沉默复合物（RISC）样复合物募集到HCV基因组的5'末端来促进丙型肝炎病毒（HCV）复制，从而稳定病毒RNA。这需要miR-122“种子序列”（核苷酸[nt] 2至8）与HCV RNA 5'端附近的两个序列：S1（nt 22至28）和S2（nt 38至43）之间的碱基配对。然而，最近的报道表明，HCV RNA和miR-122之间发生了额外的碱基对相互作用。我们从公共数据库中搜索了606个序列（基因型1至6），并鉴定了两个保守的、puplex单链RNA片段，位于S1（nt 2和3）和S2（nt 30至34）上游，具有与miR-122（分别为nt 15和16以及nt 13至16）碱基配对的潜力。突变和遗传互补实验证实，HCV nt 2和3与miR-122的nt 15和16配对结合至S1，而HCV nt 30至33与miR-122的nt 13至16在S2处配对。在基因型1和6型HCV中，nt 4也与miR-122的nt 14碱基配对。miR-122的这些3'补充碱基对相互作用在功能上是重要的，并且是通过miR-122将Ago 2募集到HCV RNA、miR-122介导的HCV RNA稳定化以及产生感染性病毒所需的。然而，虽然HCV nt 30和31处的互补突变有效地挽救了靶向S2的15 C、16 C miR-122突变体的活性，但nt 2和3处的类似突变未能挽救S1处的Ago 2募集。这些数据增加了目前对miR-122与HCV RNA相互作用的理解，但表明miR-122与HCV基因组的5' 43 nt之间的碱基配对比现有模型所建议的更复杂。
MicroRNA 122 (miR-122) facilitates hepatitis C virus (HCV) replication by recruiting an RNA-induced silencing complex (RISC)-like complex containing argonaute 2 (Ago2) to the 5' end of the HCV genome, thereby stabilizing the viral RNA. This requires base pairing between the miR-122 "seed sequence" (nucleotides [nt] 2 to 8) and two sequences near the 5' end of the HCV RNA: S1 (nt 22 to 28) and S2 (nt 38 to 43). However, recent reports suggest that additional base pair interactions occur between HCV RNA and miR-122. We searched 606 sequences from a public database (genotypes 1 to 6) and identified two conserved, putatively single-stranded RNA segments, upstream of Si (nt 2 and 3) and S2 (nt 30 to 34), with potential for base pairing to miR-122 (nt 15 and 16 and nt 13 to 16, respectively). Mutagenesis and genetic complementation experiments confirmed that HCV nt 2 and 3 pair with nt 15 and 16 of miR-122 bound to Si, while HCV nt 30 to 33 pair with nt 13 to 16 of miR-122 at S2. In genotype 1 and 6 HCV, nt 4 also base pairs with nt 14 of miR-122. These 3' supplementary base pair interactions of miR-122 are functionally important and are required for Ago2 recruitment to HCV RNA by miR-122, miR-122-mediated stabilization of HCV RNA, and production of infectious virus. However, while complementary mutations at HCV nt 30 and 31 efficiently rescued the activity of a 15C,16C miR-122 mutant targeting S2, similar mutations at nt 2 and 3 failed to rescue Ago2 recruitment at Si. These data add to the current understanding of miR-122 interactions with HCV RNA but indicate that base pairing between miR-122 and the 5' 43 nt of the HCV genome is more complex than suggested by existing models.