FIG. 5.

(A) Schematic drawing of the env expression constructs carrying the env open reading frame with the GAR region (SV-env/GAR) or the GAR region substituted for one (SV-env/M1) or two (SV-env/M2) MS2 binding sites (M). (B) Immunoblot analysis of glycoproteins expressed in HeLa-T4⁺ cells transfected with SV-env/GAR, SV-env/M1, or SV-env/M2. Viral expression vectors were cotransfected with expression vectors expressing the MS2 bacteriophage coat protein, the MS2 protein fused with the SF/ASF RS domain, or the MS2 protein fused with the SRp40 RS domain. NLS, nuclear localization signal.