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

 描述(由申请人提供)：Togaviridae家族中的甲型病毒属包含30多个成员，其中许多成员代表着不容置疑的、但往往被低估的公共卫生威胁。尽管甲型病毒能够引起广泛的流行病和严重的人类疾病，但还没有开发出针对任何甲型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、复制机制以及与宿主的相互作用缺乏了解。甲型病毒与宿主细胞的相互作用尤其鲜为人知。在我们最近的研究中，我们在理解四种甲型病毒非结构蛋白之一NSP3的功能方面取得了新的进展。这种蛋白质具有独特的结构特征，到目前为止，还没有功能被赋予。我们的初步数据表明，甲型病毒NSP3在适应细胞环境以进行有效的病毒复制方面既具有共同的功能，也具有病毒和宿主特有的功能。这些功能是由其羧基末端、高变域介导的，该结构域本质上是无序的，因此可以与广泛的宿主因子相互作用。在这项建议涵盖的研究中，我们将使用生化、分子和病毒学方法相结合的方法来表征主要与脑源性委内瑞拉马脑炎和东部马脑炎病毒的NSP3相互作用的细胞蛋白。我们将对NSP3-宿主蛋白复合体进行详细的机制研究，并描述它们在病毒特异性改变细胞内环境和确定病毒致病机制中的功能。对NSP3功能机制的研究将对了解甲型病毒复制具有重要意义，并将为抗病毒治疗的发展提供新的靶点，为甲型病毒候选疫苗的合理设计提供新的途径。

 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.