Effect of inhibitors of N-linked oligosaccharide processing on the cell surface expression of a melanoma integrin

✍ Scribed by Robert C. Spiro; David M. Laufer; Susan K. Perry; John R. Harper

• Book ID: 102877381
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 565 KB
• Volume: 41
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240410105

✦ Synopsis

The role of trimming and processing of N-linked oligosaccharides on the cell surface expression of the melanoma vitronectin receptor, a member of the integrin family of cell adhesion receptors, was examined by using specific glucosidase and mannosidase inhibitors. Inhibition of glucosidases I and I1 by castanospermine or N-methyldeoxynojirimycin delayed the vitronectin receptor a l p chain heterodimer assembly and a chain cleavage and resulted in a decrease in the level of expression cell surface receptor. Conversely, the vitronectin receptor synthesized in the presence of the mannosidase I and I1 inhibitors, 1 -deoxymannojirimycin and swainsonine, was transported normally to the cell surface with its a chain N-linked oligosaccharides in an endoglycosidase H-sensitive form. In the presence of swainsonine, time course studies of the cell surface replacement of control, endoglycosidase H-resistant receptor with an endoglycosidase Hsensitive form demonstrated a vitronectin receptor half-life of approximately 15-16 h. These studies provide evidence that the rates of assembly, proteolytic cleavage, and cell surface expression of the melanoma vitronectin receptor are dependent on the initial trimming of glucosyl residues from the a chain N-linked oligosaccharides.