Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
J Gen Virol. 2011 Jul;92(Pt 7):1627-1634. doi: 10.1099/vir.0.029231-0. Epub 2011 Mar 14.
The influenza virus RNA polymerase synthesizes three types of RNA: genomic vRNA, anti-genomic cRNA and mRNA. Both vRNA and cRNA are bound by the viral RNA polymerase and nucleoprotein to form ribonucleoprotein complexes. Viral mRNAs are also proposed to be bound by the RNA polymerase to prevent their endonucleolytic cleavage, regulate the splicing of M1 mRNA, and facilitate translation. Here, we used standard immunoprecipitation, biochemical purification and RNA immunoprecipitation assays to investigate the association of viral and host factors with viral mRNA. We found that viral mRNA associates with the viral non-structural protein 1 (NS1), cellular poly(A)-binding protein 1 (PABP1), the 20 kDa subunit NCBP1 of the nuclear cap-binding complex (CBC), the RNA and export factor-binding protein REF/Aly and the translation initiation factor eIF4E. However, our data suggest that the RNA polymerase might not form part of the viral messenger ribonucleoprotein (mRNP) complex. We propose a model in which viral mRNAs, by associating with cellular cap-binding proteins, follow the pathways normally used by cellular mRNAs for splicing, nuclear export and translation.
流感病毒 RNA 聚合酶合成三种类型的 RNA：基因组 vRNA、抗基因组 cRNA 和 mRNA。vRNA 和 cRNA 都与病毒 RNA 聚合酶和核蛋白结合，形成核糖核蛋白复合物。也有人提出，病毒 mRNA 与 RNA 聚合酶结合，以防止其内切核酸酶切割、调节 M1 mRNA 的剪接，并促进翻译。在这里，我们使用标准免疫沉淀、生化纯化和 RNA 免疫沉淀测定来研究病毒和宿主因子与病毒 mRNA 的关联。我们发现病毒 mRNA 与病毒非结构蛋白 1 (NS1)、细胞多聚 A 结合蛋白 1 (PABP1)、核帽结合复合物 (CBC) 的 20kDa 亚基 NCBP1、RNA 和出口因子结合蛋白 REF/Aly 和翻译起始因子 eIF4E 结合。然而，我们的数据表明，RNA 聚合酶可能不是病毒信使核糖核蛋白 (mRNP) 复合物的一部分。我们提出了一个模型，其中病毒 mRNA 通过与细胞帽结合蛋白结合，遵循细胞 mRNA 通常用于剪接、核输出和翻译的途径。
