title: Multidirectional effects of calmodulin kinase II on transmitter release in mature and newly formed mouse motor synapses.
abstract: Calmodulin inhibitor W-7 did not cause changes in the quantal content of postsynaptic end-plate potentials (EPP) in newly formed synapses, but prevented facilitation of acetylcholine secretion induced by L-type Ca(2+)channels blocker nitrendipine. CaMKII inhibitor KN-62 produced similar effect and suppressed the increase in EPP quantal content caused by blockade of L-type Ca(2+)channels. Phosphatase PP2A inhibitor okadaic acid significantly facilitated secretion in newly formed synapses; the effect was completely blocked by KN-62. In mature synapses, okadaic acid had no effect on transmitter secretion. KN-62 increased EPP quantal content. We hypothesize that CaMKII produced different effects on acetylcholine secretion in mature and immature synapses depending on specificity of calcium signaling and PP2A phosphatase activity.
authors.affiliation: Biological Faculty, M. V. Lomonosov Moscow State University, Russia. untergang@inbox.ru
authors.forename: P O
authors.initials: PO
authors.lastname: Bogatcheva
authors.forename: O P
authors.initials: OP
authors.lastname: Balezina
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives / Q000494:pharmacology; D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects*; D051379:Mice; D009045:Motor Endplate / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000378:metabolism; D009568:Nitrendipine / Q000494:pharmacology; D019319:Okadaic Acid / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors; D013449:Sulfonamides / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D004791:Enzyme Inhibitors; D018377:Neurotransmitter Agents; D013449:Sulfonamides; D019319:Okadaic Acid; C063302:KN 62; C017967:W 7; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D009568:Nitrendipine; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010744:Phosphoric Monoester Hydrolases; D000109:Acetylcholine