Sequence similarity between the long terminal repeat coding regions of mammary-tumorigenic BALB/cV and renal-tumorigenic C3H-K strains of mouse mammary tumor virus.
The long terminal repeat (LTR) of mouse mammary tumor virus (MMTV) encodes a protein which functions as a superantigen. The BALB/cV strain differs from other exogenous MMTVs antigenically, biochemically, on the basis of restriction fragment analysis, and by the specificity of its superantigen for V beta 2+ T cells. In order to elucidate the origin of the BALB/cV virus and to better understand the interaction of its superantigen with the T cell receptor, we have determined the nucleotide sequence of the BALB/cV LTR open reading frame, including 93 bases downstream of the translation termination site. The encoded protein's C-terminal portion, thought to control superantigenic specificity, is identical to the C3H-K strain of MMTV, isolated from a rare kidney adenocarcinoma. The remainder of the coding sequence is highly related to many MMTV strains. Like other MMTV strains, the BALB/cV LTR maintains intact an 18 base pair sequence, located downstream of the translational termination site, which is lacking in the C3H-K LTR. Sequence comparison between the BALB/cV LTR and other MMTV strains indicates that the most likely origin for the BALB/cV open reading frame sequence is a recombination event involving the endogenous provirus mtv-6.
Department of Biology, Villanova University, Pennsylvania 19085.
J J
JJ
Kang
T
T
Schwegel
J E
JE
Knepper
D000230:Adenocarcinoma / Q000382:microbiology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral; D007680:Kidney Neoplasms / Q000382:microbiology*; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000235:genetics* / Q000276:immunology
D004279:DNA, Viral; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014764:Viral Proteins