Diacylglycerol kinase is phosphorylated in vivo upon stimulation of the epidermal growth factor receptor and serine/threonine kinases, including protein kinase C-epsilon
| Autor: | J van der Wal, R L van der Bend, Dick Schaap, Hidde L. Ploegh, W J van Blitterswijk |
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| Rok vydání: | 1993 |
| Předmět: |
Diacylglycerol Kinase
Protein Kinase C-epsilon Biology Mitogen-activated protein kinase kinase Protein Serine-Threonine Kinases Transfection Biochemistry Peptide Mapping MAP2K7 Epitopes Phosphoserine Antibody Specificity 1-Methyl-3-isobutylxanthine Escherichia coli Humans ASK1 Phosphorylation Phosphotyrosine Molecular Biology Protein kinase C Cells Cultured Protein Kinase C MAP kinase kinase kinase Epidermal Growth Factor Cyclin-dependent kinase 2 Colforsin Phosphotransferases Antibodies Monoclonal Cell Biology Molecular biology Recombinant Proteins ErbB Receptors Phosphothreonine biology.protein Tetradecanoylphorbol Acetate Tyrosine Cyclin-dependent kinase 9 Protein Kinases Research Article |
| Zdroj: | The Biochemical journal. 289 |
| ISSN: | 0264-6021 |
| Popis: | In signal transduction, diacylglycerol (DG) kinase attenuates levels of the second messenger DG by converting it to phosphatidic acid. A previously cloned full-length human 86 kDa DG kinase cDNA was expressed as fusion protein in Escherichia coli, to aid in the generation of DG-kinase-specific monoclonal antibodies suitable for immunoprecipitation experiments. To investigate whether phosphorylation of DG kinase is a possible mechanism for its regulation, COS-7 cells were transiently transfected with the DG kinase cDNA and phosphorylation of the expressed DG kinase was induced by various stimuli. Activation of both cyclic AMP-dependent protein kinase and protein kinase C (PKC) resulted in phosphorylation of DG kinase on serine residues in vivo, and both kinases induced this phosphorylation within the same tryptic phosphopeptide, suggesting that they may exert similar control over DG kinase. No phosphorylation was observed upon ionomycin treatment, intended to activate Ca2+/calmodulin-dependent kinases. Co-transfections of DG kinase with either PKC-alpha or PKC-epsilon cDNA revealed that both protein kinases, when stimulated, are able to phosphorylate DG kinase. For PKC-epsilon, DG kinase is the first in vivo substrate identified. Stimulation with epidermal growth factor (EGF) of COS-7 cells transfected with both DG kinase and EGF-receptor cDNA results mainly in phosphorylation of DG kinase on tyrosine. Since the EGF receptor has an intrinsic tyrosine kinase activity, this finding implies that DG kinase may be a direct substrate for the activated EGF receptor. |
| Databáze: | OpenAIRE |
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