Tyrosine phosphorylation of protein kinase C-delta in response to its activation

• Published in: The Journal of biological chemistry 1994-01, Vol.269 (4), p.2349-2352
• Main Authors: Li, W, Mischak, H, Yu, J C, Wang, L M, Mushinski, J F, Heidaran, M A, Pierce, J H
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Adenosine Triphosphate - metabolism; Amino Acid Sequence; Animals; Biological and medical sciences; Cell physiology; Electrophoresis, Polyacrylamide Gel; Enzyme Activation; Fundamental and applied biological sciences. Psychology; Genes, src; Interleukin-3 - pharmacology; Isoenzymes - biosynthesis; Isoenzymes - isolation & purification; Isoenzymes - metabolism; Mice; Molecular and cellular biology; Molecular Sequence Data; Molecular Weight; Phosphopeptides - chemistry; Phosphopeptides - isolation & purification; Phosphoproteins - isolation & purification; Phosphoproteins - metabolism; Phosphorylation; Phosphotyrosine; Protein Kinase C - biosynthesis; Protein Kinase C - isolation & purification; Protein Kinase C - metabolism; Receptor Protein-Tyrosine Kinases - metabolism; Recombinant Proteins - biosynthesis; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Signal transduction; Substrate Specificity; Tetradecanoylphorbol Acetate - pharmacology; Transfection; Tyrosine - analogs & derivatives; Tyrosine - analysis
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/s0021-9258(17)41948-x

Retroviral vectors containing five different protein kinase C (PKC) isoenzymes (alpha, delta, epsilon, eta, zeta) were expressed in 32D hematopoietic cells and NIH-3T3 fibroblasts. In an effort to investigate signaling events regulated by PKC activation, we analyzed whether tyrosine phosphorylation of cellular proteins would occur after 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of the various transfectants. While no detectable tyrosine-specific phosphorylation was observed after treatment of the majority of the transfectants, pronounced TPA-dependent tyrosine phosphorylation of an 82-kDa protein was detected in the 32D/PKC-delta and NIH-3T3/PKC-delta lines. Interestingly, the 82-kDa substrate proved to be PKC-delta itself. Tyrosine phosphorylation of purified PKC-delta by src family or receptor tyrosine kinases in vitro enhanced PKC-delta activity, suggesting that tyrosine phosphorylation of PKC-delta may positively affect its function.