Role of Deubiquitinases in CMV Pathogenesis

项目摘要/摘要 所有病毒都必须通过细胞泛素(Ub)系统才能成功感染。泛素是一种多功能的 翻译后修饰控制许多不同的细胞过程，从蛋白质质量控制到运输 和退化到信号转导通路。序列E1-E2-E3 Ub连接酶激活的级联结果 在底物蛋白质中一个或多个Ub分子与赖氨酸残基的共价结合。不同的数组 Ub-Ub连接在很大程度上决定了Ub修饰对稳定性、本地化或功能的调节作用 目标蛋白质的数量。相反，Ub可以从修饰的蛋白质中移除，从而通过 许多脱泛素酶(DUB)的活性。所有疱疹病毒都编码与 促进病毒生命周期；然而，彻底了解这些病毒的活性、特异性和生物学 自然感染期间的病毒复制仍然不完整。我们之前已经证明了保守的配音 由小鼠巨细胞病毒(MCMV)编码的病毒在感染过程中控制炎症和病毒致病 在一个自然的宿主中。它通过调节宿主ER相关降解(ERAD)和其他途径来实现这一点，以 控制一种关键病毒趋化因子的表达和分泌。这项研究计划的目标是 确定MCMV dub在自然感染过程中促进发病的分子机制 主持人。我们的初步数据导致了MCMV dub活性既针对宿主又针对病毒的总体假设 逃避先天免疫反应和促进病毒感染的因素。这一假设将通过追查来检验 两个特定的目的：1)确定CMV dub活性调节寄主ERAD和蛋白质的机制 感染过程中的转运途径和2)确定MCMV DUB的连锁特异性靶底物 在体外和感染期间。这些努力将产生对复杂而新颖的 CMV脱泛素酶在致病机理和宿主反应中的作用，并强调了 以DUB功能为目标对抗病毒感染。

Project Summary/Abstract All viruses must navigate the cellular ubiquitin (Ub) system en route to successful infection. Ubiquitin is a versatile posttranslational modification controlling many diverse cellular processes, from protein quality control, trafficking and degradation to signal transduction pathways. Activation of sequential E1-E2-E3 Ub-ligase cascades result in covalent attachment of one or more Ub molecules to lysine residues in substrate proteins. Arrays of different Ub-Ub linkages, in large part, dictate the regulatory role of Ub modification on the stability, localization, or function of target proteins. Conversely, Ub can be removed from modified proteins to reverse its effects through the activities of numerous deubiquitinating enzymes (DUBs). All herpesviruses encode DUBs that are implicated in facilitating the viral life cycle; however, a thorough understanding of the activity, specificity, and biology of these viral DUBs during a natural infection remains incomplete. We have previously shown that the conserved DUB encoded by the murine cytomegalovirus (MCMV) controls inflammation and viral pathogenesis during infection in a natural host. It does so by regulating the host ER-associated degradation (ERAD) and other pathways, to control the expression and secretion of a critical viral chemokine. The objective of this research plan is to determine the molecular mechanisms by which MCMV DUB facilitates pathogenesis during infection in a natural host. Our preliminary data lead to the overall hypothesis that MCMV DUB activity targets both host and viral factors to evade innate immune responses and facilitate viral infection. This hypothesis will be tested by pursuing two specific aims: 1) determine the mechanisms of CMV DUB activity regulating host ERAD and protein trafficking pathways during infection and 2) determine the linkage specificity target substrates of the MCMV DUB in vitro and during infection. These efforts will yield significant mechanistic insight into the complex and novel role CMV deubiquitinases play in pathogenesis and host responses, and underscore the potential utility of targeting DUB functions to combat viral infections.