Alphavirus nsP3 protein: roles of intrinsically disordered region in virus replication and pathogenesis

 描述（由申请人提供）：披膜病毒科的甲病毒属包含30多个成员，其中许多代表了毫无疑问但经常被低估的公共卫生威胁。尽管甲病毒能够引起广泛的流行和严重的人类疾病，但尚未开发出针对任何甲病毒感染的有效疫苗或治疗手段。这主要是由于我们对它们的生物学、复制机制和与宿主的相互作用了解不足。甲病毒-宿主细胞相互作用的了解特别少。在我们最近的研究中，我们在了解四种甲病毒非结构蛋白之一nsP 3的功能方面迈出了新的步伐。这种蛋白质具有独特的结构特征，到目前为止，没有功能尚未被分配给它。我们的初步数据表明，甲病毒nsP 3表现出共同的和病毒和宿主特异性的功能，在适应细胞环境，有效的病毒复制。这些功能由其羧基末端高变结构域介导，其本质上是无序的，因此可以与广泛的宿主因子相互作用。在本提案所涵盖的研究中，我们将使用生物化学，分子和病毒学方法的组合来表征主要与致脑炎委内瑞拉马脑炎和东部马脑炎病毒的nsP 3相互作用的细胞蛋白。我们将对nsP 3-宿主蛋白复合物进行详细的机制研究，并描述它们在细胞内环境的病毒特异性修饰中的功能并定义病毒发病机制。nsP 3功能机制的研究将对理解甲病毒复制产生强烈影响，并将为开发抗病毒治疗提供新靶点，为合理设计甲病毒候选疫苗提供新方法。

 DESCRIPTION (provided by applicant): The Alphavirus genus in the Togaviridae family contains over 30 members, many of which represent an unquestionable, but often underappreciated, public health threat. In spite of the ability of alphaviruses to cause broad epidemics and severe human diseases, no efficient vaccines or therapeutic means have been developed against any alphavirus infections. This is primarily a result of our insufficient knowledge of their biology, mechanism of replication and interaction with the host. Alphavirus-host cell interaction is particularly poorly understood. In our recent studies, we have made new steps towards understanding functions of one of four alphavirus nonstructural proteins, nsP3. This protein has unique structural characteristics and so far, no functions have yet been assigned to it. Our preliminary data demonstrate that alphavirus nsP3 exhibits both common and virus- and host-specific functions in adaptation of cellular environment for efficient virus replication. These functions are mediated by its carboxy terminal, hypervariable domain, which is intrinsically disordered and thus, can interact with a wide range of host factors. In the research covered by this proposal, we will use a combination of biochemical, molecular and virological methods to characterize cellular proteins interacting primarily with the nsP3 of encephalitogenic Venezuelan equine encephalitis and eastern equine encephalitis viruses. We will perform detailed mechanistic studies of the nsP3-host protein complexes and delineate their functions in virus-specific modifications of the intracellular environment and defining viral pathogenesis. Investigation of the mechanism of the nsP3 functions will have a strong impact on understanding alphavirus replication and will provide new targets for development of antiviral therapy and new approaches for rational design of alphavirus vaccines candidates.