Regulated homodimerization of HIV-1 Rev.

<p>(A) Expression of FKBP-Rev fusion constructs. HeLa cells were transiently transfected with plasmids expressing the indicated Rev fusion proteins. Levels of protein expression were determined by Western blot analysis at 48 h post-transfection using specific anti-Rev and anti-actin (gel loading control) antibodies. (B) <i>Trans</i>-activation capacity of Rev fusion proteins. A provirus rescue assay was performed by transient cotransfection of HeLa cells with pHXB2Δ<i>rev</i> DNA, the internal control plasmid pBC12/CMV/SEAP and the indicated Rev expression vectors in the absence or presence of the chemical homodimerizer AP20187. Culture supernatants were collected at 48 h post-transfection and the accumulation of HIV-1 particles was quantified by p24^Gag antigen ELISA. Values of p24^Gag antigen were adjusted for transfection efficiency to SEAP activity in each culture supernatant.