Human c-fgr induces a monocyte-specific enzyme in NIH 3T3 cells
- Osaka Univ. (Japan)
- Univ. of Tokyo (Japan)
The mutant c-fgr protein (p58{sup c-fgr/F523}) containing Phe-523 instead of Tyr-523 exhibited transforming activity in NIH 3T3 cells like other protein-tyrosine kinases of the src family, but normal p58{sup c-fgr} (p58{sup c-fgr/wt}) did not. The mutant protein showed tyrosine kinase activity threefold higher than that of the normal protein in vitro. Surprisingly, transfection of the normal c-fgr gene into NIH 3T3 cells resulted in induction of sodium fluoride (NaF)-sensitive {alpha}-naphthyl butyrate esterase ({alpha}-NBE), marker enzyme of cells of monocytic origin, which was not induced in v-src-, v-fgr-, or lyn-transfected NIH 3T3 cells. The NaF-sensitive {alpha}-NBE induced in c-fgr transfectants was shown by isoelectric focusing to have a pI of 5.2 to 5.4, a range which was the same as those for thioglycolate-induced murine peritoneal macrophages and 1{alpha}, 25-dihydroxyvitamin D{sub 3}-treated WEHI-3B cells. Immunoblotting studies with antophosphotyrosine antibodies revealed that 58-, 62-, 75-, 120-, 200-, and 230-kDa proteins were commonly phosphorylated at tyrosine residues in NIH 3T3 cells transfected with normal and mutated c-fgr, while 95-kDa protein was significantly phosphorylated at tyrosine residues in NIH 3T3 cells transfected with normal and mutated c-fgr, while 95-kDa protein was significantly phosphorylated at tyrosine residues in cells transfected with the mutated c-fgr. These findings suggest that tyrosine phosphorylation of specific cellular substrate proteins is important in induction of NaF-sensitive {alpha}-NBE and cell transformation by p58{sup c-fgr}.
- OSTI ID:
- 5116244
- Journal Information:
- Molecular and Cellular Biology; (United States), Journal Name: Molecular and Cellular Biology; (United States) Journal Issue: 12 Vol. 11:12; ISSN MCEBD; ISSN 0270-7306
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANTIBODIES
CARBOXYLIC ACIDS
CELL DIFFERENTIATION
CELL TRANSFORMATIONS
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
ENZYME ACTIVITY
ENZYMES
FIBROBLASTS
GENES
HYDROXY ACIDS
MACROPHAGES
ONCOGENES
ONCOGENIC TRANSFORMATIONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHAGOCYTES
PHENYLALANINE
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROTEINS
SOMATIC CELLS
TRANSFERASES
TYROSINE