Tyrosine phosphorylation is an early signaling event common to Fc receptor crosslinking in human neutrophils and rat basophilic leukemia cells (RBL-2H3).
Phosphotyrosine-containing proteins were detected by western blotting of whole cell lysates of purified human neutrophils or rat basophilic leukemia cells (RBL-2H3) using a polyclonal anti-phosphotyrosine antibody. When either cell type was stimulated with the appropriate Fc crosslinking agent, heat-aggregated IgG for the neutrophil or DNP-HSA for the IgE-sensitized RBL-2H3, a rapid increase in the phosphotyrosine content of several proteins was observed. The kinetics and specificity of both responses suggest that Fc receptor crosslinking activates a receptor-associated tyrosine kinase, probably a member of the src family of tyrosine protein kinases. The subsequent tyrosine phosphorylation events are likely to be important in Fc receptor-mediated stimulus-response coupling in inflammatory cells.
Connelly
P A
PA
Central Research Division, Pfizer Inc., Groton, CT 06340.
Farrell
C A
CA
Merenda
J M
JM
Conklyn
M J
MJ
Showell
H J
HJ
D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology*; D002460:Cell Line; D015936:Complement C5a / Q000494:pharmacology; D003432:Cross-Linking Reagents; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D015759:Ionomycin / Q000494:pharmacology; D007700:Kinetics; D015471:Leukemia, Basophilic, Acute / Q000276:immunology / Q000503:physiopathology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D010766:Phosphorylation; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D011961:Receptors, Fc / Q000502:physiology*; D017455:Receptors, IgE; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
D000944:Antigens, Differentiation, B-Lymphocyte; D003432:Cross-Linking Reagents; D011961:Receptors, Fc; D017455:Receptors, IgE; D019000:Phosphotyrosine; D014443:Tyrosine; D015759:Ionomycin; D015936:Complement C5a; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D011505:Protein-Tyrosine Kinases; D013755:Tetradecanoylphorbol Acetate