c-kit protein, a transmembrane kinase: identification in tissues and characterization.
The proto-oncogene c-kit encodes a transmembrane kinase which is related to the receptors for colony-stimulating factor type 1 and platelet-derived growth factor, as well as to the immunoglobulin superfamily. Antibodies specific for the kinase domain of the P80 gag-kit protein of the Hardy-Zuckerman 4 feline sarcoma virus were prepared. These kit-specific antibodies were used to identify and characterize the c-kit protein in cat brain tissue. The c-kit protein product displays an autophosphorylating activity in immune complex kinase assays, and, in turn, this activity was used to identify the c-kit protein in different tissues. In cat brain, a single 145-kilodalton (kDa) glycoprotein was detected. Its N-linked carbohydrates were found to be sensitive to digestion with the endoglycosidases (neuraminidase, endoglycosidase F, and endoglycosidase H), indicating hybrid and/or complex and high-mannose structures. A partial purification of the c-kit protein was achieved by wheat germ agglutinin affinity chromatography, and the autophosphorylating activity of the partially purified c-kit protein was characterized and found to be specific for tyrosine. The kit antibodies cross-react with the murine c-kit protein product, and variant c-kit proteins in different mouse tissues were identified, with sizes of about 145 kDa (brain), 160 kDa (spleen), and 150 kDa (testis).
Majumder
S
S
Laboratory of Molecular Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York.
Brown
K
K
Qiu
F H
FH
Besmer
P
P
D000818:Animals; D000918:Antibody Specificity; D001921:Brain / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002415:Cats; D014644:Genetic Variation; D007120:Immunochemistry; D008297:Male; D051379:Mice; D011494:Protein Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D019009:Proto-Oncogene Proteins c-kit; D014018:Tissue Distribution
D011518:Proto-Oncogene Proteins; D011494:Protein Kinases; D019009:Proto-Oncogene Proteins c-kit