FIG. 1.

Detection of HIV-1 Vpr and p24^gag proteins in Vpr⁻, Vpr⁺, and Vpr⁺-T VSV-G-pseudotyped HIV-1. Each viral stock was produced from 293T cells cotransfected with the corresponding HIV provirus, SVCMV–VSV-G and SVCMV-VPR⁺ expressors, as described in Materials and Methods. Similar amounts of viral particles, as determined by virion-associated RT activity, were lysed in Laemmli buffer. Viral proteins were then run onto a sodium dodecyl sulfate-polyacrylamide gel and transferred to nitrocellulose. The presence of HIV p24^gag and Vpr in the viral particles was detected by immunoblotting with a monoclonal anti-HIV p24 antibody (A) or with a rabbit anti-Vpr serum (B).