Characterization of the caprine arthritis encephalitis virus (CAEV) rev N-terminal elements required for efficient interaction with the RRE.
The Caprine Arthritis Encephalitis Virus (CAEV) genome encodes three structural (gag, pol, and env) and three accessory (rev, tat, and vif) genes. The Rev-C protein regulates Gag, Pol and Env expression by transporting their mRNAs to the cytoplasm. Rev trans-activation requires binding of Rev to an RNA structure called the Rev Response Element (RRE-C). Previous mutational analyses have shown that two domains of Rev are required for its function. The basic domain mediates RRE binding and multimer formation, and the nuclear export signal (NES) mediates trans-activation. Preliminary experiments demonstrate that Rev-C N-terminal deletion mutants bind the RRE less avidly than does wildtype Rev. As a result, it was hypothesized that an additional domain located in the N-terminal exon of Rev-C was required for optimal RRE binding. To test this hypothesis, Rev-C alanine scanning mutants were generated and in vitro RRE binding assays were performed. Alteration of Rev-C amino acids K13, E14, N15, V19, T20, M21 and R27 dramatically decreased affinity for RRE-C. These data demonstrate that Rev-C N-terminal amino acids are required for optimal RRE-C binding and suggest that a third functional domain exists within the N-terminus of Rev-C.
Abelson
Michelle L
ML
Department of Microbiology, University of Minnesota College of Medicine, Minneapolis, MN 55455, USA.
Schoborg
Robert V
RV
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D016088:Arthritis-Encephalitis Virus, Caprine / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D015686:Gene Products, env / Q000235:genetics / Q000378:metabolism; D015694:Gene Products, rev / Q000378:metabolism; D015752:Genes, env; D015750:Genes, gag; D015751:Genes, pol; D015757:Genes, rev; D016679:Genome, Viral; D006023:Glycoproteins; D006041:Goats; D066298:In Vitro Techniques; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D015533:Transcriptional Activation; D014764:Viral Proteins
C412317:ENV protein, Caprine arthritis encephalitis virus; D015686:Gene Products, env; D015694:Gene Products, rev; D006023:Glycoproteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D011994:Recombinant Proteins; D014764:Viral Proteins