Activation of a Calcium-Calmodulin-dependent Protein Kinase I Cascade in PC12 Cells
| Autor: | Michele A. Selbert, Angus C. Nairn, John M. Aletta, Arthur M. Edelman |
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| Rok vydání: | 1996 |
| Předmět: |
Cytoplasm
animal structures Biology Mitogen-activated protein kinase kinase PC12 Cells Biochemistry Membrane Potentials MAP2K7 Ca2+/calmodulin-dependent protein kinase Animals ASK1 Phosphorylation Molecular Biology MAP kinase kinase kinase Cyclin-dependent kinase 5 Cyclin-dependent kinase 2 Cell Biology Molecular biology Rats Cell biology Enzyme Activation Calcium-Calmodulin-Dependent Protein Kinase Type 1 Calcium-Calmodulin-Dependent Protein Kinases biology.protein Calcium Cyclin-dependent kinase 9 Calcium Channels |
| Zdroj: | Journal of Biological Chemistry. 271:20930-20934 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.271.34.20930 |
| Popis: | It has been observed that the activity of Ca2+-calmodulin (CaM)-dependent protein kinase I is enhanced up to 50-fold by its phosphorylation in vitro by a distinct CaM kinase I kinase (Lee, J. C., and Edelman, A. M. (1994) J. Biol. Chem. 269, 2158-2164). It has, however, been unclear whether this event represents an acute form of cellular regulation. We demonstrate here the phosphorylation and activation of CaM kinase I in PC12 pheochromocytoma cells in response to elevation of intracellular Ca2+. Treatment of PC12 cells with the Ca2+-ionophore, ionomycin, or with a depolarizing concentration of KCl, led to rapid, biphasic phosphorylation of CaM kinase I and to increases in CaM kinase I activity of 5.1- and 7. 3-fold, respectively. Depolarization-induced activation of CaM kinase I was reduced by approximately 80% by blockade of Ca2+ influx through L-type voltage-dependent Ca2+ channels and completely abolished by removal of extracellular Ca2+. The ability of PC12 cell CaM kinase I to be phosphorylated and activated by purified CaM kinase I kinase in vitro was markedly reduced by prior depolarization of the cells, consistent with intracellular phosphorylation and activation of CaM kinase I by CaM kinase I kinase. These results demonstrate the existence in PC12 cells of a CaM kinase I cascade, the function of which may be to sensitize cells to signal-induced elevations of intracellular Ca2+. |
| Databáze: | OpenAIRE |
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