Specific binding of HIV-1 recombinant Rev protein to the Rev-responsive element in vitro

Abstract

The human immunodeficiency virus type 1 (HIV-1) genome encodes the regulatory protein Rev, of relative molecular mass 13,000, which is synthesized from fully processed viral transcripts before synthesis of HIV-1 structural proteins. Rev has been postulated to exert control within the nucleus at the level of messenger RNA processing. The availability of Rev in the nucleus serves to increase the proportion of unspliced and singly spliced mRNA species relative to fully spliced mRNA molecules, resulting in an increased synthesis of viral structural proteins. A highly conserved cis-acting sequence termed the Rev-responsive element (RRE) has been identified in the envelope gene (env) of the viral transcript that seems to control mRNA processing in a Rev-dependent manner. Genetic studies have identified rev gene mutants with dominant phenotypes, supporting the hypothesis that Rev interacts directly with the RRE. Here we demonstrate that Rev protein, purified from Escherichia coli, binds in a sequence-specific manner to the RRE element in vitro.