Expression of a new tyrosine protein kinase is stimulated by retrovirus promoter insertion

• Published in: Nature (London) 1986-02, Vol.319 (6055), p.682-685
• Main Authors: Voronova, Anna F., Sefton, Bartholomew M.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Cell physiology; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cell Transformation, Viral; Cells, Cultured; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Genes, Viral; Humanities and Social Sciences; letter; Mice; Molecular and cellular biology; Moloney murine leukemia virus - genetics; multidisciplinary; Myristates - metabolism; Oncogene Protein pp60(v-src); Phosphoproteins - genetics; Promoter Regions, Genetic; Protein-Tyrosine Kinases - genetics; Retroviridae Proteins - genetics; Science; Science (multidisciplinary); Sequence Homology, Nucleic Acid; Transcription, Genetic
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/319682a0

Tyrosine protein kinases are important both in the normal regulation of cellular proliferation and in the oncogenic transformation of cells by several tumour viruses 1 . The LSTRA Moloney murine leukaemia virus (M-MuLV)-induced thymoma cell line 2 contains ∼20-fold more phosphotyrosine in protein than do typical haematopoietic cell lines 3 ; this seems to result from the expression of an abnormally high level of a cellular tyrosine protein kinase termed p56 tck (refs 3,4). This kinase is normally expressed at low levels in most, but not all, murine T cells 3,4 . The elevated levels of p56 tck could contribute to the malignant properties of LSTRA cells. Therefore, we have isolated cloned complementary DNAs encoding the whole of p56 tck . Sequence analysis shows it to be a novel cellular tyrosine protein kinase which is distinct from all others described to date. p56 tck is encoded in LSTRA cells by a hybrid messenger RNA; ∼200 nucleotides at the 5′ end of the mRNA are identical to the 5′ end of the genome of M-MuLV. The three- to ninefold transcriptional activation of the gene therefore results from retroviral promoter insertion.