FIG. 3.

Processing and location of PRRSV GP₃ protein individually expressed in 293 cells with the recombinant AdCMV5/ORF3 virus. (A) Adherent 293 cells at 80% confluency (10⁷) were infected with AdCMV5/ORF3 at an MOI of 20 to 30 TCID₅₀/cell. At 24 h p.i., cells were pulse-labelled with [³⁵]methionine for 30 min (time zero), chased for the indicated times, and processed for radioimmunoprecipitation with α3 antiserum. Aliquots of immunoprecipitates were treated with Endo H or Glyco F or were left untreated (UNT) and were then analyzed by SDS–12% PAGE. The data indicated that Ad-expressed GP₃ was much more stable than PRRSV-expressed GP₃. (B) Cells infected with the recombinant AdCMV5/ORF3 virus were pulse-labelled for 30 min and chased for the indicated times as described for panel A. Expression of GP₃ was monitored by radioimmunoprecipitation in either the cell lysates or the culture medium. Numbers on the right indicate the positions and sizes of ¹⁴C-radiolabelled marker proteins.