Control of translation by VSV

描述（由申请人提供）：翻译控制在许多病毒的发病机制中起关键作用。抑制宿主蛋白质合成对于抑制宿主抗病毒应答是重要的，而病毒mRNA的选择性翻译对于病毒在宿主中的繁殖是重要的。水泡性口炎病毒（VSV）的翻译控制，原型弹状病毒，是一个最好的研究的例子中的非节段负链RNA病毒。先前的实验已经清楚地表明，VSV使用新的机制来控制翻译，这与其他研究充分的RNA病毒（如小核糖核酸病毒和流感病毒）不同。本项目的目标是确定VSV抑制宿主蛋白质合成和促进病毒蛋白质合成的机制。先前的工作表明，翻译因子eIF2 α在VSV感染的细胞中由于蛋白激酶R的磷酸化而失活。然而，我们已经表明帽结合eIF4F复合物在VSV感染的细胞中也被灭活。目的1是确定eIF4F如何失活，以及eIF4F相对于eIF2 α失活在VSV感染的细胞中抑制宿主蛋白质合成中的相对贡献。目的2是确定负责诱导宿主蛋白质合成抑制的病毒组分。这些研究将使用新的重组病毒来定位VSV突变体的基因，这些突变体在抑制宿主翻译方面比野生型VSV更有效或更无效。目的3是确定病毒mRNA对翻译抑制的抗性的基础。这些实验将使用含有病毒或宿主5'和3'非翻译区的嵌合mRNA来测试增强病毒mRNA翻译的顺式作用序列的存在。我们还将测试表达这些嵌合mRNA的重组病毒，以确定病毒转录酶的mRNA合成是否赋予对翻译抑制的抗性。这些实验完成后，我们将获得关于病毒如何抑制宿主抗病毒反应以及它们如何促进自身基因产物表达的重要新信息。这些实验的结果将是新颖的，因为VSV使用的机制与其他研究充分的原型病毒有很大的不同。最后，很可能存在使用类似于VSV mRNA的机制的宿主mRNA，以在诸如应激的条件下增强其翻译。因此，我们希望获得新的见解，在其他条件下，翻译起始因子的活动受到抑制的细胞翻译的调控。

DESCRIPTION (provided by applicant): The control of translation plays a critical role in the pathogenesis of many viruses. The inhibition of host protein synthesis is important for suppression of the host antiviral response, while the selective translation of viral mRNAs is important for virus propagation in the host. Translational control by vesicular stomatitis virus (VSV), the prototype rhabdovirus, is one of the best studied examples among the nonsegmented negative stranded RNA viruses. Previous experiments have made it clear that VSV uses novel mechanisms to control translation that are distinct from those of other well-studied RNA viruses, such as picornaviruses and influenza viruses. The goal of this project is to determine these mechanisms by which VSV inhibits host protein synthesis and promotes viral protein synthesis. Previous work has shown that the translation factor elF2alpha is inactivated in VSV-infected cells as a result of phosphorylation by protein kinase R. However, we have shown that the cap-binding elF4F complex is also inactivated in VSV-infected cells. Aim 1 is to determine how elF4F is inactivated, and the relative contribution of elF4F versus elF2alpha inactivation in the inhibition of host protein synthesis in VSV-infected cells. Aim 2 is to determine the viral components responsible for inducing the inhibition of host protein synthesis. These studies will use new recombinant viruses to map the genes of VSV mutants that are either more effective or less effective than wild-type VSV in the inhibition of host translation. Aim 3 is to determine the basis of resistance of viral mRNAs to the inhibition of translation. These experiments will use chimeric mRNAs containing viral or host 5' and 3' untranslated regions to test for the presence of cis-acting sequences that enhance translation of viral mRNAs. We will also test recombinant viruses that express these chimeric mRNAs to determine whether mRNA synthesis by the viral transcriptase confers the resistance to the inhibition of translation. Upon completion of these experiments we will have important new information about how viruses suppress the antiviral response in the host, and how they promote expression of their own gene products. The results of these experiments will be novel, because the mechanisms used by VSV differ substantially from those of other well-studied prototype viruses. Finally, it is very likely that there are host mRNAs that use mechanisms similar to those of VSV mRNAs to enhance their translation under conditions such as stress. Thus we expect to gain new insight into regulation of cellular translation under other conditions where the activities of translation initiation factors are inhibited.