Activation of Ca2+/calmodulin-dependent protein kinase (CaM-kinase) IV by CaM-kinase kinase in Jurkat T lymphocytes.
Ca2+/calmodulin-dependent protein kinase IV (CaM-kinase IV), a member of the CaM-kinase family involved in transcriptional regulation, is stimulated by Ca2+/CaM but also requires phosphorylation by a CaM-kinase kinase for full activation. In this study we investigated the physiological role of a CaM-kinase cascade in Jurkat T human lymphocytes through antigen receptor (CD3) signaling. Total and Ca(2+)-independent CaM-kinase IV activities were increased 8-14-fold by anti-CD3 antibody. This CD3-mediated activation involved phosphorylation since the immunoprecipitated CaM-kinase IV from stimulated Jurkat cells could be subsequently inactivated in vitro by protein phosphatase 2A. CaM-kinase IV immunoprecipitated from unstimulated Jurkat cells or CD3-negative mutant Jurkat cells could be activated in vitro 10-40-fold by CaM-kinase kinase purified from rat brain or thymus, whereas CaM-kinase IV from CD3-stimulated wild-type Jurkat cells was only activated to 2-3-fold by exogenous CaM-kinase kinase. CaM-kinase IV activation was triggered by Ca2+ acting through calmodulin since activation could also be elicited by ionomycin treatment, and CD3-mediated activation was blocked by the calmodulin antagonist calmidazolium. These data are consistent with a CaM-kinase cascade in which CaM-kinase IV is activated by a CaM-kinase kinase cascade triggered by elevated intracellular calcium in Jurkat cells.
Park
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IK
Vollum Institute, Oregon Health Sciences University, Portland 97201-3098, USA.
Soderling
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TR
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015153:Blotting, Western; D001921:Brain / Q000201:enzymology; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002460:Cell Line; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D015759:Ionomycin / Q000494:pharmacology; D007700:Kinetics; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism; D054648:Protein Phosphatase 2; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology / Q000502:physiology; D013601:T-Lymphocytes / Q000201:enzymology
D000911:Antibodies, Monoclonal; D002147:Calmodulin; D004791:Enzyme Inhibitors; D007093:Imidazoles; D010446:Peptide Fragments; D017260:Receptor-CD3 Complex, Antigen, T-Cell; C031938:calmidazolium; D015759:Ionomycin; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C517683:CAMK4 protein, human; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517686:Camk4 protein, rat; D020929:Mitogen-Activated Protein Kinase Kinases; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2