Activation of Ca2+/calmodulin-dependent protein kinase I in cultured rat hippocampal neurons.
We have focused on activation mechanisms of calcium/calmodulin-dependent protein kinase (CaM) kinase I in the hippocampal neurons and compared them with that of CaM kinase IV. Increased activation of CaM kinase I occurred by stimulation with glutamate and depolarization in cultured rat hippocampal neurons. Similar to CaM kinases II and IV, CaM kinase I was essentially activated by stimulation with the NMDA receptor. Although both CaM kinases I and IV seem to be activated by CaM kinase kinase, the activation of CaM kinase I was persistent during stimulation with glutamate in contrast to a transient activation of CaM kinase IV. In addition, CaM kinase I was activated in a lower concentration of glutamate than that of CaM kinase IV. Depolarization-induced activation of CaM kinase I was also evident in the cultured neurons and was largely blocked by nifedipine. In the experiment with 32P-labeled cells, phosphorylation of CaM kinase I was stimulated by glutamate treatment and depolarization. The glutamate- and depolarization-induced phosphorylation was inhibited by the NMDA receptor antagonist and nifedipine, respectively. These results suggest that, although CaM kinases I and IV are activated by the NMDA receptor and depolarization stimulation, these kinase activities are differently regulated in the hippocampal neurons.
Uezu
Akiyoshi
A
Department of Pharmacology, Kumamoto University School of Medicine, Kumamoto, Japan.
Fukunaga
Kohji
K
Kasahara
Jiro
J
Miyamoto
Eishichi
E
D000818:Animals; D000918:Antibody Specificity; D002121:Calcium Channel Blockers / Q000494:pharmacology; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D009543:Nifedipine / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors
D002121:Calcium Channel Blockers; D004791:Enzyme Inhibitors; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517599:Camk1 protein, rat; C517686:Camk4 protein, rat; C517682:Pnck protein, rat; D009543:Nifedipine