A cluster of conserved basic amino acids near the C-terminus of the PB1 subunit of the influenza virus RNA polymerase is involved in the regulation of viral transcription
A cluster of conserved basic amino acids near the C-terminus of the PB1 subunit of the influenza virus RNA polymerase is involved in the regulation of viral transcription
复制标题
DOI：
10.1016/j.virol.2007.11.030
复制
发表时间：
2008-03-30
期刊：
影响因子：
3.7
通讯作者：
Fodor, Ervin
中科院分区：
文献类型：
--
作者：
Kerry, Philip S.;Willsher, Nicholas;Fodor, Ervin
通过病毒RNA聚合酶复合物合成流感病毒mRNA由加帽的RNA片段引发，所述加帽的RNA片段通过聚合酶亚基PB 1对宿主前体mRNA进行内切核酸酶切割而产生。在以前的研究中，核酸内切酶和启动子结合位点已被描述在PB 1的C-末端区域。在这里，我们已经确定了一个额外的区域附近的C-末端的PB 1参与生产加帽RNA引物的病毒转录。特别地，碱性氨基酸K669、R670和R672的突变抑制引物依赖性病毒mRNA合成。相反，引物非依赖性cRNA和vRNA合成仅受到轻微影响。此外，与cRNA相比，含有K669 A或R672 A突变的重组病毒在感染期间表达的mRNA量减少，并且在细胞培养物中被减弱。进一步的体外分析表明，这些突变通过减少与vRNA启动子和加帽RNA的结合来抑制聚合酶启动mRNA合成的能力。这些结果表明，该区域在病毒mRNA转录的调节中起着关键作用。(C)2007年爱思唯尔公司All rights reserved.
Synthesis of influenza virus mRNA by the viral RNA polymerase complex is primed by capped RNA fragments generated by endonuclease cleavage of host pre-mRNA by the polymerase subunit PB1. In previous studies, endonuclease and promoter-binding sites have been described in the C-terminal region of PB1. Here, we have identified an additional region near the C-terminus of PB1 involved in producing capped RNA primers for viral transcription. In particular, mutations of basic amino acids K669, R670, and R672 inhibited primer-dependent viral mRNA synthesis. In contrast, primer-independent cRNA and vRNA syntheses were only marginally affected. Additionally, recombinant viruses containing the K669A or R672A mutations expressed reduced amounts of mRNA compared to cRNA during infection and were attenuated in cell culture. Further in vitro analysis showed that these mutations inhibited the ability of the polymerase to initiate mRNA synthesis by causing a reduction in binding to the vRNA promoter and capped RNA. These results suggest that this region plays a critical role in the regulation of viral mRNA transcription. (C) 2007 Elsevier Inc. All rights reserved.