Winslow G M, Marrack P, Kappler J W
Howard Hughes Medical Institute, Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
Immunity. 1994 Apr;1(1):23-33. doi: 10.1016/1074-7613(94)90006-x.
Mouse mammary tumor viruses produce superantigens (vSAGs) which interact with class II major histocompatibility complex (MHC) proteins and stimulate T cells. vSAGs are synthesized as Type II membrane proteins, but at least one of these proteins (vSAG7) is found on the cell surface in a proteolytically processed form. Monoclonal antibodies (MAbs) were used to characterize vSAG7 and its binding to class II molecules. vSAG7 is synthesized in the endoplasmic reticulum (ER) as a 45 kd glycoprotein containing N-asparagine-linked oligomannosyl carbohydrates. vSAG7 transits the golgi complex, where it is modified by the addition of complex-type glycans and proteolysed at three positions. After proteolysis, the amino and carboxyl termini remain noncovalently associated. The ER, golgi, and surface forms of vSAG7 are stably bound to class II, but one of the proteolysed forms comprises the majority of the class II-bound material.
小鼠乳腺肿瘤病毒产生超抗原（vSAGs），这些超抗原与II类主要组织相容性复合体（MHC）蛋白相互作用并刺激T细胞。vSAGs作为II型膜蛋白合成，但这些蛋白中至少有一种（vSAG7）以蛋白水解加工形式存在于细胞表面。单克隆抗体（MAbs）用于表征vSAG7及其与II类分子的结合。vSAG7在内质网（ER）中作为一种45kd的糖蛋白合成，含有N-天冬酰胺连接的寡甘露糖碳水化合物。vSAG7穿过高尔基体，在那里它通过添加复合型聚糖进行修饰，并在三个位置进行蛋白水解。蛋白水解后，氨基和羧基末端保持非共价结合。vSAG7的内质网、高尔基体和表面形式与II类稳定结合，但其中一种蛋白水解形式构成了与II类结合物质的大部分。
