Transfection of Syk protein tyrosine kinase reconstitutes high affinity IgE receptor-mediated degranulation in a Syk-negative variant of rat basophilic leukemia RBL-2H3 cells.

• DOI: 10.1084/jem.184.1.71
• Publication Date: 2004-06-24T07:56:10Z
• Authors: J Zhang; E H Berenstein; R L Evans; R P Siraganian
• Keywords: 0301 basic medicine; Enzyme Precursors; Phospholipase C gamma; Receptors, IgE; Receptor Aggregation; Intracellular Signaling Peptides and Proteins; Protein-Tyrosine Kinases; Transfection; Histamine Release; Basophils; Rats; Isoenzymes; 03 medical and health sciences; Leukemia, Basophilic, Acute; Type C Phospholipases; Tumor Cells, Cultured; Animals; Syk Kinase; Calcium; Mast Cells; Phosphotyrosine; Signal Transduction

Aggregation of the high affinity receptor for immunoglobulin E (Fc epsilon RI) on mast cells results in rapid tyrosine phosphorylation and activation Syk, a cytoplasmic protein kinase. To examine role Syk Fc RI signaling pathway, we identified variant RBL-2H3 that has no detectable by immunoblotting vitro kinase reactions. In these Syk-deficient TB1A2 cells, aggregation induced histamine release increase total cellular phosphorylation. However, stimulation with calcium ionophore did induce degranulation. beta gamma subunits receptor, but phospholipase C-gamma 1 2 intracellular free Ca2+ concentration. By transfection, cloned lines were established stable expression Syk. reconstituted 2, an release. These demonstrate plays critical early RI-mediated events. It further demonstrates occurs downstream phosphorylation, upstream most phosphorylations.