Definition of the RRE Binding and Activation Domains of the Caprine Arthritis Encephalitis Virus Rev Protein

• Published in: Virology (New York, N.Y.) Vol. 226; no. 1; pp. 113 - 121
• Main Authors: Schoborg, R.V., Clements, J.E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-1996
• Subjects: AIDS/HIV; Amino Acid Sequence; Arthritis-Encephalitis Virus, Caprine - genetics; Arthritis-Encephalitis Virus, Caprine - metabolism; Binding Sites; caprine arthritis encephalitis virus; ENCEFALITIS; ENCEPHALITE; Gene Products, rev - metabolism; Genes, env; human immunodeficiency virus 1; Leucine; Molecular Sequence Data; RNA, Viral - metabolism; Sequence Homology, Amino Acid; VIRUS DE LOS ANIMALES; VIRUS DES ANIMAUX; visna virus
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1006/viro.1996.0633

Caprine arthritis encephalitis virus (CAEV) is a lentivirus which is closely related by nucleotide sequence and biological properties to visna virus and is more distantly related to the human AIDS virus, HIV-1. Previous studies indicated that the CAEV Rev protein (Rev-C) functions as atrans-activator of mRNA cytoplasmic transport and expression. The function of Rev-C is mediated through an RNA element (RRE-C) present between nucleotides (nt) 7906 and 8110 in the CAEVenvgene. In this study, RNA/protein immunoprecipitation experiments were used to demonstrate that Rev-C binds directly to the 204-nt RRE-Cin vitro.Competition assays illustrate that this interaction is specific for the positive sense RRE-C RNA. Glutaraldehyde crosslinking studies demonstrate that the wildtype Rev-C protein can also form multimeric complexesin vitro.Deletions or amino acid alterations within the basic domain of Rev-C reduce affinity for the RRE and disrupt assembly of Rev-C multimersin vitro,indicating that this domain is involved in RRE binding and Rev multimer formation. Mutations within the leucine-rich domain of Rev-C do not greatly effect RRE-C binding or self-assembly. However, previous results demonstrate that some leucine-rich domain mutants are unable totrans-activate. These data are consistent with the hypothesis that the leucine domain is the effector domain of Rev-C.