The Cell Biology of Coronavirus Infection

描述(申请人提供)：冠状病毒是正链RNA病毒，可在人类引起呼吸道感染，在其他动物物种中引起重要的胃肠道和神经疾病。小鼠肝炎病毒(MHV)是研究冠状病毒复制和致病机制的模型。这项拟议研究的中心目标是确定小鼠肝炎病毒在病毒复制复合体形成和功能过程中与宿主细胞的相互作用。MHV在分布于细胞质中的膜复制复合体上指导病毒RNA的合成。这些复合体不同于高尔基体中间隔室的病毒粒子组装部位(ERGIC)。从复制酶基因多聚蛋白加工而来的蛋白质与核衣壳(N)蛋白一起定位在病毒RNA合成的两个密切相关的蛋白质复合体中，即p22/p65复合体和hel/N复合体。在感染后期，helN复合体从p22/p65复合体中分离出来，并转移到ERGIC中病毒粒子的组装位置。然而，复制复合体的确切组成尚不清楚，HEL/N复合体易位的机制也尚未确定。这项建议描述了一项综合研究计划，以确定MHV复制复合体的组织和移位。在特定目标1中，将确定MHV复制复合体的蛋白质和膜组成。在具体目标2中，将确定hel/N复合体转位到ERGIC的机制。在具体目标3中，将确定病毒蛋白在复制复合体易位中的功能。这些研究将确定MHV指导复制复合体形成和功能的基本机制，并将确定对成功复制病毒至关重要的病毒-细胞相互作用。

DESCRIPTION (provided by applicant): Coronaviruses are positive-strand RNA viruses that cause respiratory infections in humans and important gastrointestinal and neurologic disease in other animal species. Mouse hepatitis virus (MHV) is a model for studies of coronavirus replication and pathogenesis. The central goal of the proposed research is to define interactions of mouse hepatitis virus with host cells during formation and function of viral replication complexes. MHV directs viral RNA synthesis on membranous replication complexes that are distributed thoughout the cytoplasm. These complexes are distinct from sites of virion assembly in the intermediate compartment of the Golgi (ERGIC). Proteins processed from the replicase gene polyprotein localize with the nucleocapsid (N) protein at sites of viral RNA synthesis in two closely associated protein complexes, the p22/p65 complex and the hel/N complex. At late times of infection, the hel/N complexes separate from the p22/p65 complexes and translocate to sites of virion assembly in the ERGIC. However, the precise composition of replication complexes is not known, and the mechanism of hel/N complex translocation has not been determined. This proposal describes an integrated research program to define the organization and translocation of MHV replication complexes. In Specific Aim 1, the protein and membrane composition of MHV replication complexes will be determined. In Specific Aim 2, the mechanism of hel/N complex translocation to the ERGIC will be defined. In Specific Aim 3, the functions of viral proteins in replication complex translocation will be determined. These studies will identify fundamental mechanisms by which MHV directs replication complex formation and function and will define virus-cell interactions that are essential for successful virus replication.