Fig 3.
CBFβ is required for HIV-1 Vif to degrade all Vif-sensitive human APOBEC3 proteins. (A) Percent infectivity of HIV-1LAI measured by duplicate infection of CEM-GFP cells and flow cytometry, reported as the mean ± standard deviation of the results for the technical replicate. Constant amounts of Vif-proficient HIV-1LAI proviral construct (1 μg) were cotransfected with increasing concentrations of each human HA-tagged APOBEC3 protein (0, 50, or 100 ng) in the presence or absence of CBFβ isoform 2 complementation vector (25 ng) as indicated. (B) Immunoblots of CBFβ, Vif, and the HA-tagged human APOBEC3 proteins in cell lysates and of the APOBEC3 proteins in HIV particles produced by those cells. Tubulin (TUB) and p24 (CA) served as cell and viral lysate loading controls.