Gonzalez A, Rizzolo L, Rindler M, Adesnik M, Sabatini D D, Gottlieb T
Proc Natl Acad Sci U S A. 1987 Jun;84(11):3738-42. doi: 10.1073/pnas.84.11.3738.
The demonstration that the envelope glycoproteins G of vesicular stomatitus virus and hemagglutinin of influenza virus synthesized in polarized epithelial cells transfected with the corresponding genes are effectively segregated to the basolateral or apical plasma membrane domains, respectively, implies that the information determining this segregation resides within the structures of the proteins themselves. To localize the sorting information within these proteins, the polarity of secretion of truncated hemagglutinin and G glycoproteins secreted from confluent monolayers of MDCK cells transformed with vectors containing the corresponding truncated cDNAs was examined. It was found that, even though the transformed cells continued to secrete a major endogenous glycoprotein exclusively from the apical surface, the modified viral glycoproteins were secreted in a nonpolarized fashion from both sides of the monolayers. These observations suggest that important information for the sorting of the viral glycoprotein is contained within their membrane anchoring or cytoplasmic segments or that, if sorting signals are luminally located, these signals must be present in a conformation that is not attainable when the polypeptides are not attached to the membrane.
水泡性口炎病毒的包膜糖蛋白G和流感病毒的血凝素，在用相应基因转染的极化上皮细胞中合成时，分别有效地分隔到基底外侧或顶端质膜结构域，这表明决定这种分隔的信息存在于蛋白质自身的结构中。为了在这些蛋白质中定位分选信息，检测了用含有相应截短cDNA的载体转化的MDCK细胞汇合单层分泌的截短血凝素和G糖蛋白的分泌极性。结果发现，尽管转化细胞继续仅从顶端表面分泌一种主要的内源性糖蛋白，但修饰的病毒糖蛋白以非极化方式从单层的两侧分泌。这些观察结果表明，病毒糖蛋白分选的重要信息包含在它们的膜锚定或细胞质区段中，或者，如果分选信号位于腔内，这些信号必须以多肽未附着于膜时无法获得的构象存在。
