Sequence-specific RNA binding by the HIV-1 Rev protein

Abstract
THE human immunodeficiency virus type 1 (HIV-1) Rev protein acts post-transcriptionally to increase the amounts of the viral gag-pol and env messenger RNAs in the cytoplasm of infected cells1,2. The mechanism of Rev action is uncertain. Possibilities include an accelerating effect on the rate of export of its mRNA targets from the nucleus3–6 and/or modulation of the splicing of pre-mRNAs (reviewed in ref. 7). Both the gag-pol and env mRNAs contain a sequence that is required for responsiveness to Rev—the Rev responsive element, RRE3,4,6,8. Here we show that Rev is a sequence-specific binding protein, whose binding site is the RRE. This information should help to clarify the mechanism by which Rev acts.