FIG. 3.

Construction and expression of CD4/Vpu proteins in HeLa cells. (A) Primary sequences of wt and mutant Vpu transmembrane domains in CD4/Vpu hybrid proteins. (B) Expression of CD4/Vpu proteins (lanes 1 to 16). Plasmids (3 μg of each) encoding CD4 VpuF and each of the mutant CD4/Vpu proteins were introduced into vTF7-3-infected HeLa cells. Transfected cells were labeled with [³⁵S]methionine for 1 h and lysed by RIPA. Detergent lysates were immunoprecipitated with anti-Vpu antibody and resolved by SDS-PAGE (10% gel). Arrow a indicates fully glycosylated proteins, and arrow b represents partially glycosylated or unglycosylated CD4/Vpu proteins. Sizes are indicated in kilodaltons.