EndoH sensitivities of coexpressed GP2a, GP3, and GP4 proteins. BHK-21 cells were coinfected with different combinations of SFV-ORF2a, SFV-ORF3, and SFV-ORF4 as indicated above the lanes. The cells were pulse-chase labeled as described in the legend to Fig. 4A. The cells were lysed, and the GP2a, GP3, and GP4 proteins were subjected to immunoprecipitation with anti-GP2a (α-GP2a), anti-GP3 (α-GP3), or anti-GP4 (α-GP4) antibodies. Precipitates were either left untreated (−EndoH; left-hand panels) or treated with EndoH (+EndoH; right-hand panels).