FIG. 8.

Us9 is a type II membrane protein. Us9-EGFP-containing virions were isolated from the medium of Us9-EGFP-expressing cells infected with PRV Be or Ba (MOI = 10) as described in Materials and Methods. The purified PRV Be virions (A) or Ba virions (B and C) were treated with (lanes 3 and 4) or without (lanes 1 and 2) proteinase K in either the presence (lanes 2 and 4) or absence (lanes 1 and 3) of 1% NP-40. The samples were then fractionated on an SDS–12.5% polyacrylamide gel and analyzed by Western blotting with either Us9 (A and B) or GFP (C) antiserum. Positions of molecular mass markers (kilodaltons) are indicated on the left.