HIV Rev Response Element - Relationship To Other Viruses

Relationship To Other Viruses

All complex retroviruses face the problem of exporting unspliced and partially spliced mRNAs. Some use systems similar to Rev/RRE; these include HIV-2 and SIV (Simian Immunodeficiency Virus) which use their own Rev-RRE systems, some betaretroviruses, which use a Rem/RmRE system, and all deltaretroviruses which use a Rex/RxRRE systems.

Many simple retroviruses, most notably Mason–Pfizer monkey virus (MPMV), do not encode a Rev-like protein, but instead have evolved a cis-acting RNA element, the constitutive transport element (CTE), that directly binds to components of the host mRNA export machinery. The MPMV CTE is ~220 nucleotides and consists of two identical binding sites for the cellular export protein Tap. Tap directly binds the viral RNA and exports it to the cytoplasm.