Functional rescue of an oligomerization-defective HIV-1 Rev mutant by fusion with an oligomeric tag.

The HIV-1 wild-type Rev and the negative oligomerization-defective mutant RevM4 were fused to enhanced green fluorescent protein (EGFP) and the tetrameric red fluorescent protein (DsRed1) followed by examination of their intracellular localization and Rev activity. As previously shown, fusion of EGFP to Rev and RevM4 did not affect the biological activity. Fusion of DsRed1 to Rev inhibited activity, and interestingly, fusion of DsRed1 to RevM4 restored activity. Based on these results, a model is proposed suggesting how RevM4-DsRed1 is able to rescue Rev activity through oligomerization on the viral RNA.