Role of HCMV Glycoprotein in Viral Biogenesis

描述(申请人提供)：人巨细胞病毒是一种 无处不在的病原体，是免疫受损疾病的主要原因 个人，如艾滋病和骨髓移植患者。人巨细胞病毒是 也是最常见的先天性病毒感染，是导致 儿童传染性中枢神经系统发育不良。尽管它在临床上很重要 这种病毒的病原体，对其分子和细胞基础知之甚少 人巨细胞病毒在感染细胞中的组装。目前的巨细胞病毒模型表明 在将病毒衣壳运送到细胞质后，它们被包裹在 跨高尔基体网络(TGN)及其相关的内体隔室 膜上布满了包膜糖蛋白。正确定位和 需要对包膜糖蛋白进行加工才能生产 传染性病毒。了解巨细胞病毒生物发生的关键是确定 将成熟糖蛋白定位于 病毒组装的隔间(S)。红豆杉细胞生物学最新研究进展 主要的人巨细胞病毒包膜糖蛋白gB，一种重要的疱疹病毒糖蛋白， 结果表明：1)人巨细胞病毒gB定位于TGN并分选到根尖表面 在极化细胞(HCMV释放表面)，2)TGN的定位是 通过GB与细胞连接器PACS-1和3的相互作用而介导) 抑制依赖于呋喃的gb切割会导致错误的排序 未加工的糖蛋白，并与生产中的戏剧性障碍相结合 传染性病毒。 本申请的目的是确定Gb在HCMV组装中的作用。 为了实现这一目标，我们将解决四个具体目标：1)确定 顺式作用分选标志着GB直接绑定到PAC-L和GB 基序和结构域是指导TGN本地化和 分类，2)确定PACS-1介导的GB定位的机制(S) TGN，以及这种相互作用对生产的要求 感染性巨细胞病毒，3)研究依赖呋喃的加工在 Gb在病毒糖蛋白的TGN定位和病毒组装中，4) 确定GB TGN定位、内体分选和 用重组人巨细胞病毒分析病毒装配中依赖呋喃的蛋白降解 表达在这些过程中有缺陷的gb基因。总而言之，这些研究将 增加我们对人巨细胞病毒gB的细胞生物学的知识，并提供对 病毒组装的分子机制将使疾病的发展 治疗病毒疾病的新疗法。

DESCRIPTION (provided by applicant): Human cytomegalovirus (HCMV) is a ubiquitous pathogen that is a major cause of disease in immunocompromised individuals, such as AIDS and bone marrow transplantation patients. HCMV is also the most common congenital viral infection and is the leading cause of infectious CNS maldevelopment in children. Despite the clinical importance of this viral pathogen, little is known regarding the molecular and cellular basis of HCMV assembly in infected cells. Current models of HCMV suggest that following transport of viral capsids to the cytoplasm, they are enveloped at the trans-Golgi Network (TGN) and associated endosomal compartments by membranes studded with envelope glycoproteins. Correct localization and processing of the envelope glycoproteins is required for the production of infectious virus. Key to understanding HCMV biogenesis is a determination of the cellular and molecular mechanisms that localize the mature glycoproteins to the compartment(s) of viral assembly. Recent studies of the cell biology of the major HCMV envelope glycoprotein gB, an essential herpes virus glycoprotein, show that: 1) HCMV gB is localized to the TGN and sorts to the apical surface in polarized cells (the surface of HCMV release), 2) TGN localization is mediated by interaction of gB with the cellular connector, PACS- 1, and 3) inhibition of furin-dependent cleavage of gB causes missorting of the unprocessed glycoprotein and is coupled with a dramatic block in the production of infectious virus. The goal of this application is to determine the role of gB in HCMV assembly. To achieve this goal, we will address four specific aims: 1) identify the cis-acting sorting signals that direct binding of gB to PACS-l and the gB motifs and domains necessary and sufficient to direct the TGN localization and sorting, 2) determine the mechanism(s) of PACS-1-mediated localization of gB to the TGN, and the requirement of this interaction for the production of infectious HCMV, 3) investigate the role of the furin-dependent processing of gB in both TGN localization of the viral glycoprotein and in virus assembly, 4) determine the role of gB TGN localization, endosome sorting, and furin-dependent proteolysis in virus assembly by analysis of HCMV recombinants expressing gB genes defective in these processes. Together, these studies will increase our knowledge of the cell biology of HCMV gB and provide insight into the molecular mechanisms of viral assembly that will enable development of novel therapeutics to treat viral disease.