FIG. 3.

Biosynthesis of the foreign glycoproteins expressed after infection with rVSVs. VeroE6 cells were infected with rVSVs at an MOI of 10. (A) For cells infected with VSVΔG/MARVGP, proteins were pulse labeled at 24 h postinfection for 30 min with 20 μCi of [³⁵S]cysteine per ml and chased for 240 min. GP-specific proteins were immunoprecipitated from cell lysates with mouse anti-Marburg virus GP immunoglobulin (II9G4) (dilution, 1:800) and analyzed on SDS-10% PAGE under reducing conditions. The presence of decRVKR (25 μM) during labeling and chase abolished cleavage of pre-GP (lane 2). (B) For cells infected with VSVΔG/EBOVGP, cells were lysed 24 h postinfection and analyzed by Western blotting with a GP₁-specific antibody at a dilution of 1:4,000 (lane 1) and GP₂-specific rabbit antiserum at a dilution of 1:2,000 (lane 2). (C) For cells infected with VSVΔG/LASVGPC, cells were lysed 24 h postinfection and analyzed by Western blotting with a GP2-specific antiserum (dilution, 1:2,000). (D) For cells infected with wild-type VSV (VSVwt) (lane 1), VSV/ZEBOVsGP (lane 2), and VSV/MARVGP₁ (lane 3), supernatants were analyzed 12 h postinfection by Western blotting with a VSV G-specific antibody (dilution, 1:1,000), a Zaire Ebola virus GP-specific antibody (12/1.1; dilution, 1:4,000), and a Marburg virus GP₁-specific antibody (5EII; dilution, 1:4,000).