title: Nucleic acid sequences of the oncogene v-rel in reticuloendotheliosis virus strain T and its cellular homolog, the proto-oncogene c-rel.
abstract: Reticuloendotheliosis virus strain T (Rev-T) is a highly oncogenic replication-defective retrovirus which contains the oncogene v-rel. It is thought that Rev-T arose when a virus similar to Rev-A, the helper virus of Rev-T, infected a turkey and recombined with c-rel from that turkey. There is one large c-rel locus in the turkey genome which contains all of the sequences homologous to v-rel (K. C. Wilhelmsen and H. M. Temin, J. Virol. 49:521-529, 1984). We have sequenced v-rel and its flanking sequences, each of the regions of the c-rel locus from turkey that are homologous to v-rel and their flanking sequences, and the coding sequence for env and part of pol of Rev-A. The v-rel coding sequences can be translated into a 503-amino acid env-v-rel-out-of-frame-env fusion polypeptide. We have not detected any sequences in the Los Alamos or University of California-San Diego data bases that are more significantly related to the amino acid or nucleic acid sequence of v-rel than to the randomized sequence of v-rel. Comparison of Rev-A, Rev-T, and c-rel indicates that the v-rel sequences may have been transduced from the c-rel (turkey) locus by a novel mechanism. There are sequences in Rev-A and c-rel that are similar to splicing signals, indicating that the 5' virus-rel junction of Rev-T may have been formed by cellular RNA splicing machinery. Eight presumed introns have presumably been spliced out of c-rel to generate v-rel. There are also short imperfect regions of homology between sequences at the boundaries of v-rel and sequences in Rev-A and c-rel (turkey), indicating that c-rel may have been transduced by homologous recombination. There are many differences between the amino acid sequences of the predicted translational products of v-rel and c-rel which may account for their difference in transformation potential. These sequence differences between v-rel and c-rel include 10 missense transitions, four missense transversions, and three places where Rev-T has a small in-frame deletion of sequences relative to c-rel. Most of the coding sequence differences between c-rel and v-rel are nonconservative amino acid changes.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D005814:Genes, Viral; D008979:Moloney murine leukemia virus / Q000235:genetics; D009857:Oncogenes; D014176:Protein Biosynthesis; D012190:Retroviridae / Q000235:genetics*; D014422:Turkeys
chemical_list: D004251:DNA Transposable Elements; D004262:DNA Restriction Enzymes