Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.
RNA Biol. 2012 Aug;9(8):1110-9. doi: 10.4161/rna.21208. Epub 2012 Aug 1.
Translation initiation of hepatitis C Virus (HCV) RNA is the initial obligatory step of the viral life cycle, mediated through the Internal Ribosome Entry Site (IRES) present in the 5'-untranslated region (UTR). Initiation on the HCV IRES is mediated by multiple structure-specific interactions between IRES RNA and host 40S ribosomal subunit. In the present study we demonstrate that the SLIIIef domain, in isolation from other structural elements of HCV IRES, retain the ability to interact with 40S ribosome subunit. A small RNA SLRef, mimicking the SLIIIef domain was found to interact specifically with human La protein and the ribosomal protein S5 and selectively inhibit HCV RNA translation. More importantly, SLRef RNA showed significant suppression of replication in HCV monocistronic replicon and decrease of negative strand synthesis in HCV cell culture system. Finally, using Sendai virus based virosome, the targeted delivery of SLRef RNA into mice liver succeeded in selectively inhibiting HCV IRES mediated translation in vivo.
丙型肝炎病毒 (HCV) RNA 的翻译起始是病毒生命周期的初始必需步骤，通过 5'非翻译区 (UTR) 中存在的内部核糖体进入位点 (IRES) 介导。HCV IRES 的起始由 IRES RNA 与宿主 40S 核糖体亚基之间的多个结构特异性相互作用介导。在本研究中，我们证明了 SLIIIef 结构域，在不与 HCV IRES 的其他结构元件结合的情况下，保留了与 40S 核糖体亚基相互作用的能力。发现一个类似于 SLIIIef 结构域的小 RNA SLRef 可特异性地与人 La 蛋白和核糖体蛋白 S5 相互作用，并选择性地抑制 HCV RNA 翻译。更重要的是，SLRef RNA 显著抑制 HCV 单顺反子复制子中的复制，并减少 HCV 细胞培养系统中的负链合成。最后，利用仙台病毒载体，成功地将 SLRef RNA 靶向递送至小鼠肝脏，在体内选择性地抑制了 HCV IRES 介导的翻译。
