title: Src family tyrosine kinase p53/56lyn, a serine kinase and Fc epsilon RI associate with alpha-galactosyl derivatives of ganglioside GD1b in rat basophilic leukemia RBL-2H3 cells.
abstract: The monoclonal antibody (mAb) AA4 recognizes two alpha-galactosyl derivatives of the GD1b ganglioside on rat mast cells and on the rat basophilic leukemia RBL-2H3 cultured cell line. Here we demonstrate that mAb AA4 coprecipitated both protein tyrosine and serine kinases. In contrast, a monoclonal antibody to the GD3 ganglioside did not coprecipitate any kinase activity. In kinase assays of mAb AA4 immunoprecipitates there were phosphorylated proteins of 71-80, 53/56, and 41/42 kDa. All proteins were phosphorylated on tyrosine, whereas the 71-80- and 41/42-kDa proteins were also phosphorylated on serine residues. The precipitation of these proteins by mAb AA4 correlated with the presence of the alpha-galactosyl derivatives of GD1b. The 53/56-kDa proteins were identified as the Src-related tyrosine kinase p53/56lyn. The presence of p53/56lyn in the mAb AA4 immunoprecipitates was specific and was observed when several different detergents were used. The same 71-80-kDa tyrosine-phosphorylated proteins were immunoprecipitated by mAb AA4 and anti-Lyn antibodies and may play a role in the interaction of p53/56lyn with the gangliosides. Although there is a weak association of the high affinity IgE receptor with these gangliosides, the coprecipitation of p53/56lyn with mAb AA4 was not secondary to the association of this kinase with receptor. These complexes of gangliosides and several proteins that include p53/56lyn, a serine kinase, and the high affinity IgE receptor could play an important role in receptor-mediated signal transduction.
authors.affiliation: Laboratory of Immunology, National Institute of Dental Research, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: K
authors.initials: K
authors.lastname: Minoguchi
authors.forename: W D
authors.initials: WD
authors.lastname: Swaim
authors.forename: E H
authors.initials: EH
authors.lastname: Berenstein
authors.forename: R P
authors.initials: RP
authors.lastname: Siraganian
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001345:Autoradiography; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005697:Galactosides / Q000032:analysis / Q000378:metabolism*; D005732:Gangliosides / Q000302:isolation & purification / Q000378:metabolism*; D015151:Immunoblotting; D015471:Leukemia, Basophilic, Acute; D008407:Mast Cells / Q000201:enzymology; D008970:Molecular Weight; D010761:Phosphorus Radioisotopes; D017346:Protein Serine-Threonine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D017455:Receptors, IgE / Q000302:isolation & purification / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D019061:src-Family Kinases
chemical_list: D000911:Antibodies, Monoclonal; D005697:Galactosides; D005732:Gangliosides; D010761:Phosphorus Radioisotopes; D017455:Receptors, IgE; C033851:ganglioside, GD1b; D011505:Protein-Tyrosine Kinases; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D017346:Protein Serine-Threonine Kinases