Identification of the differentiation-associated p93 tyrosine protein kinase of HL-60 leukemia cells as the product of the human c-fes locus and its expression in myelomonocytic cells.
A differentiation-associated 93-kDa tyrosine kinase (p93) was purified previously from the human promyelocytic leukemia cell line HL-60. The present study conclusively identifies p93 as the c-fes proto-oncogene product and shows that expression of p93c-fes and its associated tyrosine kinase activity are marked in mature granulocytes, monocytes, and human myeloid leukemia cell lines. Antisera to peptides obtained by expression of c-fes cDNA fragments in Escherichia coli reacted strongly with p93 purified from HL-60 cells. Western blots using one of these antisera demonstrated high levels of p93c-fes protein in normal human granulocytes and monocytes, as well as the cell lines KG-1, THP-1, HEL, and U-937, all of which can be induced to differentiate along the myelomonocytic pathway. Conversely, in cell lines resistant to myeloid differentiation, p93c-fes expression was either very low or absent. Expression of immunoreactive p93c-fes in these cell lines showed a strong positive correlation with p93c-fes tyrosine kinase activity, which was measured in cell extracts using a nondenaturing gel assay. Finally, the expression of p93c-fes, its tyrosine kinase activity, and the binding of 125I-granulocyte-macrophage colony-stimulating factor (GM-CSF) were all coordinately increased in HL-60 cells treated with the granulocytic differentiation inducer dimethyl sulfoxide, while all three parameters were low in untreated or differentiation-resistant HL-60 cells. These results suggest that expression of p93c-fes tyrosine kinase activity may be an essential component of myeloid differentiation and responsiveness to granulocyte-macrophage colony-stimulating factor.
Smithgall
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Laboratory of Biological Chemistry, National Cancer Institute, Bethesda, Maryland 20892.
Yu
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Glazer
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D015153:Blotting, Western; D002454:Cell Differentiation; D002460:Cell Line; D005796:Genes; D006801:Humans; D015479:Leukemia, Myelomonocytic, Acute / Q000201:enzymology / Q000235:genetics; D015473:Leukemia, Promyelocytic, Acute / Q000201:enzymology / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011519:Proto-Oncogenes
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011505:Protein-Tyrosine Kinases