Hypoglycosylation of Gas1 stimulates shedding by native Yps1. A) Schematic view of Gas1p glycosylation profile and putative cleavage sites as depicted for Yps1 (Figure 7A). B) Cell extracts (C; 5.0 × 106 cells equivalent) and concentrated supernatants (S; 10-times more material compared to cell extracts) from 24 h cultures at pH 6.0 of the indicated yeast mutants (all strains are also yps1Δ) either transformed (pYPS1) or untransformed with plasmid Yps1 were separated by 10% SDS-PAGE and immunodetected with a Gas1 antiserum. Asterisks point to faint discrete Gas1 species detected above the major 80 kDa species in the extracellular milieu. The percentage of total Gas1-immunoreactive material (%T) associated with cell extracts and supernatants is indicated for all strains.