ROLE OF GLYCOPROTEIN-B OF HERPES-SIMPLEX VIRUS TYPE-1 IN VIRAL ENTRY AND CELL-FUSION
ROLE OF GLYCOPROTEIN-B OF HERPES-SIMPLEX VIRUS TYPE-1 IN VIRAL ENTRY AND CELL-FUSION
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DOI：
10.1128/jvi.62.8.2596-2604.1988
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发表时间：
1988-08-01
影响因子：
5.4
通讯作者：
PERSON, S
中科院分区：
文献类型：
--
作者：
CAL, WH;GU, BH;PERSON, S
1型单纯疱疹病毒糖蛋白B （gB）是一种包膜蛋白，对病毒生长至关重要。我们之前报道了两种gB-null病毒的分离，它们在非允许细胞中形成无gb病毒粒子。在目前的研究中，这些无gb病毒粒子被证明以与野生型病毒相同的速度结合到细胞表面。然而，它们无法形成斑块，也无法在感染时合成病毒特异性蛋白质。经膜融合剂聚乙二醇处理后，镀层效率显著提高。因此，在病毒附着之后、病毒特异性蛋白表达之前的一个阶段，需要gB。分离到一株gB-null合胞病毒，该病毒含有gB缺陷，并在另一个遗传位点发生合胞突变。它使转化的gB细胞完全融合，而未转化的细胞没有融合，表明gB在病毒诱导的细胞融合中起重要作用。位于gB细胞质域中两个独立位点的突变被转移到病毒DNA上，并显示出病毒具有合胞表型。建立了一种瞬时表达试验，以确定一组含有gB基因添加和无义突变的质粒对gB-null合胞病毒中细胞融合缺陷的补足能力。质粒中的突变，包括那些位于gB胞质外结构域的突变，被发现降低了gB的融合活性。因此，gB含有不同的功能区域负责融合诱导和抑制。
Glycoprotein B (gB) of herpes simplex virus type 1 is an envelope protein that is essential for viral growth. We previously reported the isolation of two gB-null viruses, which form gB-free virions in nonpermissive cells. In the present study, these gB-free virions were shown to bind to the cell surface at the same rate as the wild-type virus. They failed, however, to form plaques and to synthesize virus-specific proteins upon infection. Their plating efficiency was significantly enhanced by treatment with polyethylene glycol, a membrane fusion agent. Therefore, gB is required in a stage after viral attachment but before the expression of the virus-specific proteins. A gB-null syncytial virus was isolated, which contained a gB defect and syncytial mutation in another genetic locus. It caused complete fusion of gB-transformed cells but no fusion on untransformed cells, indicating the essential role of gB in virus-induced cell fusion. Mutations located at two independent sites in the cytoplasmic domain of gB were transferred to viral DNA and shown to confer a syncytial phenotype to the virus. A transient-expression assay was developed to determine the ability of a set of plasmids containing addition and nonsense mutations in the gB gene to complement the cell-fusion defect in the gB-null syncytial virus. Mutations in plasmids, including those located in the extracytoplasmic domain of gB, were identified that reduced the fusion activity of gB. Therefore, gB contains different functional regions responsible for fusion induction and its inhibition.