Presynaptic Ryanodine Receptor-Activated Calmodulin Kinase II Increases Vesicle Mobility and Potentiates Neuropeptide Release

• DOI: 10.1523/jneurosci.1879-07.2007
• Publication Date: 2007-07-18T17:28:28Z
• Authors: Dinara Shakiryanova; Markus K. Klose; Yi Zhou; Tingting Gu; David L. Deitcher; Harold L. Atwood; Randall S. Hewes; Edwin S. Levitan
• Keywords: 0301 basic medicine; Hot Temperature; Phosphodiesterase Inhibitors; Green Fluorescent Proteins; Neuropeptides; Neuromuscular Junction; Presynaptic Terminals; Electric Stimulation; Animals, Genetically Modified; 03 medical and health sciences; Caffeine; Larva; Calcium-Calmodulin-Dependent Protein Kinases; Mutation; Animals; Drosophila Proteins; Calcium; Drosophila; Drug Interactions; Enzyme Inhibitors; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Calcimycin

Although it has been postulated that vesicle mobility is increased to enhance release of transmitters and neuropeptides, the mechanism responsible for increasing motion in nerve terminals effect perturbing this mobilization on synaptic plasticity are unknown. Here, green fluorescent protein-tagged dense-core vesicles (DCVs) imaged Drosophila motor neuron terminals, where DCV minutes after seconds activity. Ca2+-induced Ca2+ from presynaptic endoplasmic reticulum (ER) shown be necessary sufficient sustained mobilization. However, ryanodine receptor (RyR)-mediated short-lived only initiates signaling. Calmodulin kinase II (CaMKII), which not activated directly by external influx, then acts as a downstream effector released ER Ca2+. RyR CaMKII essential post-tetanic potentiation neuropeptide secretion. Therefore, signaling pathway identified required plasticity.