Rothman J E, Fine R E
Proc Natl Acad Sci U S A. 1980 Feb;77(2):780-4. doi: 10.1073/pnas.77.2.780.
The G protein of vesicular stomatitis virus is a transmembrane glycoprotein that is transported from its site of synthesis in the rough endoplasmic reticulum to the plasma membrane via the Golgi apparatus. Clathrin-coated vesicles have been purified from CHO cells infected with vesicular stomatitis virus and shown to contain G protein in amounts nearly stoichiometric with clathrin. Pulse-chase experiments have demonstrated that this G protein is a transit form and have revealed that G is transported to the cell surface in two successive waves of coated vesicles. The oligosaccharides of G1 protein carried in the early wave are of the "high-mannose" variety which can be cleaved by the enzyme endoglycosidase H; the oligosaccharides of G2 protein in the second, later wave are resistant to endoglycosidase H. The early wave is therefore proposed to correspond to transport of G protein in coated vesicles from the endoplasmic reticulum to the Golgi apparatus, where the oligosaccharides are processed and resistance to endoglycosidase H is conferred; the succeeding wave would represent transport from the Golgi apparatus to the plasma membrane.
水泡性口炎病毒的G蛋白是一种跨膜糖蛋白，它从粗面内质网的合成位点经高尔基体转运至质膜。网格蛋白包被小泡已从感染水泡性口炎病毒的CHO细胞中纯化出来，并显示其中所含G蛋白的量与网格蛋白几乎呈化学计量关系。脉冲追踪实验表明，这种G蛋白是一种过渡形式，并揭示G蛋白以两波连续的包被小泡转运至细胞表面。早期波中携带的G1蛋白的寡糖是“高甘露糖”类型，可被内切糖苷酶H切割；后期第二波中G2蛋白的寡糖对内切糖苷酶H具有抗性。因此，早期波被认为对应于G蛋白在包被小泡中从内质网转运至高尔基体，在高尔基体中寡糖被加工并获得对内切糖苷酶H的抗性；随后的波则代表从高尔基体转运至质膜。
