FIG. 6.

Vpu does not prevent MLV/GaLV Env surface expression. (A) Schematic of surface labeling experiment. 293FT cells were transfected HIV-CMV-GFP (+/− Vpu) in the presence or absence of MLV Env-GFP or MLV/GaLV Env-GFP. At 48 h posttransfection, cells were collected and stained live for surface GFP expression with Alexa Fluor 647-conjugated anti-GFP antibody, and the supernatant was transferred to 293T mCAT-1 cells and assayed for infectivity. (B) Surface expression and infectivity of Env proteins. The average surface GFP intensity/total GFP intensity of transfected cells is reported in the upper right-hand corner of surface expression scatter plots. Infectivity scatter plots show infections on the x axis; the y axis (FL2) is not relevant for this experiment, but is used to maintain visual consistency. Infectivity is shown in each plot as the percentage of the 293T mCAT-1 cells infected with HIV-CMV-GFP.