Processing of the asparagine-linked oligosaccharides of secreted and intracellular forms of the vesicular stomatitis virus g protein: In vivo evidence of golgi apparatus compartmentalization

Abstract

The structures of the asparagine-linked oligosaccharides of several variant forms of the vesicular stomatitis virus glycoprotein transiently expressed from cloned cDNAs have been determined. Glycopeptides isolated from forms of the G protein that reach the cell surface or that are secreted into the medium are virtually identical; they contain complextype oligosaccharides whose nonreducing ends terminate in galactose and sialic acid residues. In contrast, forms of the G protein that remain intracellular possess oligosaccharides at intermediate stages in the processing pathway. One deletion mutant, A1473, codes for a protein that remains in the rough endoplasmic reticulum (Rose, J. K., and J. E. Bergmann, 1982, Cell, 30:753-762) and contains only high mannose-type oligosaccharides. Another mutant, 11554, codes for a glycoprotein that contains oligosaccharides of primarily two classes. One class is of the high mannose type and is similar to those found on the protein coded for by A1473. However, the major class contains biantennary and more highly branched complex-type oligosaccharides that terminate in N-acetylglucosamine rather than galactose or sialic acid residues. These data suggest that the protein coded for by 11554 migrates to the Golgi apparatus, but does not enter the more distal compartment(s) of the organelle which contains galactosyl- and sialyltransferases. © 1985, Rockefeller University Press., All rights reserved.