Tyrosine phosphorylation of protein kinase C-delta in response to the activation of the high-affinity receptor for immunoglobulin E modifies its substrate recognition.
The delta isoform of protein kinase C is phosphorylated on tyrosine in response to antigen activation of the high-affinity receptor for immunoglobulin E. While protein kinase C-delta associates with and phosphorylates this receptor, immunoprecipitation of the receptor revealed that little, if any, tyrosine-phosphorylated protein kinase C-delta is receptor associated. In vitro kinase assays with immunoprecipitated tyrosine-phosphorylated protein kinase C-delta showed that the modified enzyme had diminished activity toward the receptor gamma-chain peptide as a substrate but not toward histones or myelin basic protein peptide. We propose a model in which the tyrosine phosphorylation of protein kinase C-delta regulates the kinase specificity toward a given substrate. This may represent a general mechanism by which in vivo protein kinase activities are regulated in response to external stimuli.
Haleem-Smith
H
H
Section of Chemical Immunology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892-1820, USA.
Chang
E Y
EY
Szallasi
Z
Z
Blumberg
P M
PM
Rivera
J
J
D000818:Animals; D000941:Antigens / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology / Q000502:physiology; D007073:Immunoglobulin E / Q000494:pharmacology; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D015471:Leukemia, Basophilic, Acute; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011493:Protein Kinase C / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D017455:Receptors, IgE / Q000302:isolation & purification / Q000378:metabolism*; D015398:Signal Transduction; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014443:Tyrosine
D000941:Antigens; D007527:Isoenzymes; D017455:Receptors, IgE; D019000:Phosphotyrosine; D007073:Immunoglobulin E; D014443:Tyrosine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate