Localization of the RNA Binding Domain of the Bovine Immunodeficiency Virus Rev Protein

The Lentivirus life replication cycle involves the synthesis of viral RNAs. These RNAs are divided in three groups: fully spliced, partially spliced and unspliced mRNAs. As described in HIV-1, the fully spliced viral mRNAs encode regulatory proteins including Tat and Rev whereas the partially spliced viral mRNAs produce enzymatic and structural proteins. The unspliced RNAs are template for genomic viral RNAs that will be packaged for the production of progeny viruses [1,2]. The fully spliced viral mRNAs are exported from the nucleus to the cytoplasm of the infected cells through standard cellular machinery. In contrast, nuclear exportation of unspliced and partially spliced viral mRNAs is accomplished with the involvement of the HIV-1 Rev protein[1]. Rev forms a multimeric protein complex on the Rev responsive element (RRE), a secondary RNA structure that is present in unspliced and partially spliced viral mRNAs [3].