THE SMALL ENVELOPE GLYCOPROTEIN (G(S)) OF EQUINE ARTERITIS VIRUS FOLDS INTO 3 DISTINCT MONOMERS AND A DISULFIDE-LINKED DIMER
THE SMALL ENVELOPE GLYCOPROTEIN (G(S)) OF EQUINE ARTERITIS VIRUS FOLDS INTO 3 DISTINCT MONOMERS AND A DISULFIDE-LINKED DIMER
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DOI：
10.1128/jvi.69.6.3441-3448.1995
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发表时间：
1995-06-01
影响因子：
5.4
通讯作者：
ROTTIER, PJM
中科院分区：
文献类型：
--
作者：
DEVRIES, AAF;RAAMSMAN, MJB;ROTTIER, PJM
马动脉炎病毒（EAV）的小膜糖蛋白（G（S））是一种次要的病毒体成分，但在EAV感染的细胞中大量表达。在这项研究中，我们分析了它的膜拓扑结构，折叠，寡聚化，和细胞内运输。我们表明，G（S）是一个I类完整的膜蛋白与一个功能的N-糖基化位点。在非还原条件下的凝胶电泳显示，G（S）在EAV感染的细胞中以四种单体构象和二硫键连接的同源二聚体形式存在。迁移最慢的单体形式对应于完全还原的G（S）蛋白;三种迁移最快的单体物质可能是通过分子中三个腔半胱氨酸之间形成替代性链内二硫键而产生的。G（S）单体选择性地保留在内质网中，根据它们对糖苷内切酶H的永久敏感性来判断，而G（S）二聚体特异性地掺入病毒颗粒中，并在通过高尔基体的过程中变得对糖苷内切酶H具有抗性并被唾液酸化。
The small membrane glycoprotein (G(S)) of equine arteritis virus (EAV) is a minor virion component but is abundantly expressed in EAV-infected cells. In this study, we have analyzed its membrane topology, folding, oligomerization, and intracellular transport. We show that G(S) is a class I integral membrane protein with one functional N-glycosylation site. Gel electrophoresis under nonreducing conditions revealed that G(S) occurs in EAV-infected cells in four monomeric conformations and as disulfide-linked homodimers. The slowest-migrating monomeric form corresponded to the fully reduced G(S) protein; the three faster-migrating monomeric species are probably generated by the formation of alternative intrachain disulfide bonds between the three luminal cysteines in the molecule. The G(S) monomers were selectively retained in the endoplasmic reticulum, as judged by their permanent susceptibility to endoglycosidase H, whereas the G(S) dimers were specifically incorporated into virus particles and became endoglycosidase H resistant and sialylated during passage through the Golgi apparatus.