RNA-Free and Ribonucleoprotein-Associated Influenza Virus Polymerases Directly Bind the Serine-5-Phosphorylated Carboxyl-Terminal Domain of Host RNA Polymerase II.
RNA-Free and Ribonucleoprotein-Associated Influenza Virus Polymerases Directly Bind the Serine-5-Phosphorylated Carboxyl-Terminal Domain of Host RNA Polymerase II.
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DOI：
10.1128/jvi.00494-16
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发表时间：
2016-07-01
影响因子：
5.4
通讯作者：
Fodor E
中科院分区：
文献类型：
--
作者：
Martínez-Alonso M;Hengrung N;Fodor E
流感病毒会颠覆宿主的转录机制，合成自己的病毒mRNA。细胞RNA聚合酶II(POL II)的持续转录是病毒合成信使核糖核酸所必需的。通过一种被称为帽子抢夺的过程，病毒从宿主有帽子的RNA中窃取短的5‘端有帽子的RNA片段，并用它们来启动病毒转录。甲型流感病毒RNA聚合酶与POLII大亚基的C末端结构域之间的相互作用已经建立，但这种相互作用的分子细节仍不清楚。我们在这里证明了流感病毒核糖核蛋白(VRNP)复合体与转录参与的POL II的CTD结合。此外，我们提供了证据表明，在存在和不存在病毒RNA的情况下，病毒聚合酶直接与POL II CTD的丝氨酸-5-磷酸化形式结合，并表明这种相互作用在进化上较远的流感病毒中是保守的。我们提出了一个模型，在该模型中，vRNPs背景下的病毒RNA聚合酶在感染早期直接与Pol II结合促进了帽子的抢夺，而我们认为在感染后期游离病毒聚合酶与Pol II的结合可能会引发Pol II的降解。流感病毒引起每年流行和偶尔流行，对人类健康构成威胁，并给全球卫生保健系统带来巨大的经济负担。现有的疫苗并不总是有效的，因为它们可能与正在传播的病毒不完全匹配。此外，现有的抗病毒药物数量有限，对这些药物产生抗药性是一个令人担忧的问题。抗击流感的新措施是需要的，但在开发这些措施之前，有必要更好地了解流感病毒及其宿主细胞之间的分子相互作用。通过对流感病毒如何劫持宿主转录机制的分子细节提供进一步的见解，我们的目标是发现抗病毒药物开发的新靶点。
Influenza viruses subvert the transcriptional machinery of their hosts to synthesize their own viral mRNA. Ongoing transcription by cellular RNA polymerase II (Pol II) is required for viral mRNA synthesis. By a process known as cap snatching, the virus steals short 5′ capped RNA fragments from host capped RNAs and uses them to prime viral transcription. An interaction between the influenza A virus RNA polymerase and the C-terminal domain (CTD) of the large subunit of Pol II has been established, but the molecular details of this interaction remain unknown. We show here that the influenza virus ribonucleoprotein (vRNP) complex binds to the CTD of transcriptionally engaged Pol II. Furthermore, we provide evidence that the viral polymerase binds directly to the serine-5-phosphorylated form of the Pol II CTD, both in the presence and in the absence of viral RNA, and show that this interaction is conserved in evolutionarily distant influenza viruses. We propose a model in which direct binding of the viral RNA polymerase in the context of vRNPs to Pol II early in infection facilitates cap snatching, while we suggest that binding of free viral polymerase to Pol II late in infection may trigger Pol II degradation. IMPORTANCE Influenza viruses cause yearly epidemics and occasional pandemics that pose a threat to human health, as well as represent a large economic burden to health care systems globally. Existing vaccines are not always effective, as they may not exactly match the circulating viruses. Furthermore, there are a limited number of antivirals available, and development of resistance to these is a concern. New measures to combat influenza are needed, but before they can be developed, it is necessary to better understand the molecular interactions between influenza viruses and their host cells. By providing further insights into the molecular details of how influenza viruses hijack the host transcriptional machinery, we aim to uncover novel targets for the development of antivirals.