A single mutation in one of the CORE elements of Moloney murine leukemia virus reduced binding of a 42-kDa T lymphoma cell nuclear factor but did not affect lymphomagenesis

• Published in: Molecular carcinogenesis Vol. 3; no. 2; p. 93
• Main Authors: Case, R S, Khang, Y H, Kumar, A, Yuen, P H
• Format: Journal Article
• Language: English
• Published: United States 1990
• Subjects: Animals; Base Sequence; Cell Transformation, Viral; Cloning, Molecular; DNA Probes; DNA, Viral - analysis; Enhancer Elements, Genetic; Lymphoma - genetics; Lymphoma - pathology; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Moloney murine leukemia virus - genetics; Mutation; Nuclear Proteins - genetics; T-Lymphocytes - metabolism; Tumor Cells, Cultured
• ISSN: 0899-1987
• DOI: 10.1002/mc.2940030207

The genetic determinant responsible for virulence in Moloney murine leukemia virus (MoMuLV) induced T-cell lymphomagenesis has recently been mapped [J Virol 63:471-480, 1989] by homologous genomic fragment exchange between MoMuLV and MoMuLV-TB to the Clal/Xbal at the 3' end of the genome. This region of MoMuLV and MoMuLV-TB differs in 11 nucleotides. Of these 11 nucleotide differences, 9 are distributed within the two CORE, the two distal NF1, and the two GRE/LVa elements of the enhancer. Since both the CORE binding sites of MoMuLV-TB are mutated with respect to those of MoMuLV, we compared nuclear proteins of a thymus-bone marrow cell line and a T-lymphoma cell line (EMT), which bind to the wild-type and mutant CORE binding sites. Using both the bandshift assay and southwestern analysis with labeled synthetic deoxyoligonucleotides, we showed that a 42-kDa protein from TB and EMT cells bound specifically to the MoMuLV CORE element. The T---C transversion of nucleotide 6 of the CORE consensus, TGTGGT/CTAA, significantly reduced binding of the 42-kDa TB and EMT cell factors. However, the transversion of nucleotide 3 from T---C had little effect on the binding of the 42-kDa protein to the CORE element. In addition, the 42-kDa protein bound weakly to the CCAAT element of MoMuLV. A recombinant virus, NwtTB-6, was generated by introducing the two CORE mutations of MoMuLV-TB into the MoMuLV genome. Although the latency period of NwtTB-6 in the induction of lymphoma was not significantly different from that of MoMuLV, preliminary findings suggest that the lymphoma induced by NwtTB-6 may be more widely distributed.