FIGURE 6.

HSP70 regulates HIV-1 infectivity in an APOBEC3G-dependent manner. A, 293T cells (5 × 10⁵) were co-transfected with 0.1 μg of pNL4-3 or pNL4-3-delta-Vif and 1.0 μg of pc-Hu-APOBEC3G-HA alone, pFLAG-HSP70 (0.5, 1.0, or 2.0 μg) alone or 1.0 μg of pc-Hu-APOBEC3G-HA and pFLAG-HSP70 (0.5, 1.0 or 2.0 μg). At 48 h post-transfection, supernatants were harvested, and the amount of each virus was normalized to the equivalent level of p24. MAGI cells (1 × 10⁴) were infected with serially diluting supernatants of each stock of virus, and infected cells were stained with X-Gal 2 days later. 50% tissue culture infective doses (TCID50) is determined by the last virus dilution that is still capable of infecting the cells. B, each stock of cell lysate or virus in A was subjected to Western blotting and was then analyzed with the indicated antibody. All data are representative of three independent experiments.