title: IgE-induced tyrosine phosphorylation of phospholipase C-gamma 1 in rat basophilic leukemia cells.
abstract: Stimulation of rat basophilic leukemia (RBL-2H3) cells with oligomeric IgE elicited a rapid and transient phosphorylation of phospholipase C (PLC)-gamma 1 on tyrosine residues. Prior incubation of RBL-2H3 cells with a protein tyrosine kinase inhibitor, herbimycin A, prevented the tyrosine phosphorylation of PLC-gamma 1 as well as the hydrolysis of phosphatidylinositol 4,5-bisphosphate induced by oligomeric IgE. However, 5'-(N-ethyl)carboxamidoadenosine, which is known to activate PLC through a G protein, did not elicit tyrosine phosphorylation of PLC-gamma 1. These results, together with previous findings showing that tyrosine phosphorylation of PLC-gamma 1 enhances its catalytic activity, indicate that phosphorylation of PLC-gamma 1 by a nonreceptor tyrosine kinase is the mechanism by which IgE receptor aggregation triggers PLC activation.
authors.affiliation: Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: D J
authors.initials: DJ
authors.lastname: Park
authors.forename: H K
authors.initials: HK
authors.lastname: Min
authors.forename: S G
authors.initials: SG
authors.lastname: Rhee
mesh_terms: D000818:Animals; D016227:Benzoquinones; D015153:Blotting, Western; D004789:Enzyme Activation; D007073:Immunoglobulin E / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D047029:Lactams, Macrocyclic; D015471:Leukemia, Basophilic, Acute; D010766:Phosphorylation; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); D011233:Precipitin Tests; D011809:Quinones / Q000494:pharmacology; D051381:Rats; D017828:Rifabutin / Q000031:analogs & derivatives; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D016227:Benzoquinones; D007527:Isoenzymes; D047029:Lactams, Macrocyclic; D011809:Quinones; D017828:Rifabutin; D007073:Immunoglobulin E; D014443:Tyrosine; C020754:herbimycin; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C068961:phosphatidylinositol 4,5-biphosphate kinase; D010738:Type C Phospholipases