Fig. 6.

Glycosylation and cell-surface expression of WT and W203A. (A) cell-surface biotinylated samples of WT, W203A, and vector clones were analyzed for receptor glycosylation. Western blot analysis indicates that comparable levels of fully glycosylated WT and mutant receptors are expressed at the cell surface. Treating glycosylated mature receptors with glycosidase enzymes Endo H cleaves the chitobiose core of high mannose and some hybrid oligosaccharides from N-linked glycoproteins. Treatment of samples with PNGase F cleaves between the innermost GlcNAc and asparagine residues of high mannose, hybrid, and complex oligosaccharides from N-linked glycoproteins. (B) Western blot analysis of Rho-GDI, an abundant cytosolic protein, as a control for cytosolic contamination. Data shown in (A) are from a single experiment and are representative of four independent experiments; data in (B) are representative of three independent experiments.