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Modulation of CaV2.1 channels by Ca2+/calmodulin-dependent protein kinase II bound to the C-terminal domain.

TitleModulation of CaV2.1 channels by Ca2+/calmodulin-dependent protein kinase II bound to the C-terminal domain.
Publication TypeJournal Article
Year of Publication2008
AuthorsJiang X, Lautermilch NJ, Watari H, Westenbroek RE, Scheuer T, Catterall WA
JournalProceedings of the National Academy of Sciences of the United States of America
Date Published2008 Jan 8
KeywordsAntigens, CD8, Protein Binding, Brain, Calcium, Calcium Channels, N-Type, Calcium-Calmodulin-Dependent Protein Kinase Type 2, Wasps, Humans, Models, Biological, Mutation, Neurons, Phosphorylation, Protein Structure, Tertiary, Synaptic Transmission

<p>Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is a key regulator of synaptic responses in the postsynaptic density, but understanding of its mechanisms of action in the presynaptic neuron is incomplete. Here we show that CaMKII constitutively associates with and modulates voltage-gated calcium (Ca(V))2.1 channels that conduct P/Q type Ca(2+) currents and initiate transmitter release. Both exogenous and brain-specific inhibitors of CaMKII accelerate voltage-dependent inactivation, cause a negative shift in the voltage dependence of inactivation, and reduce Ca(2+)-dependent facilitation of Ca(V)2.1 channels. The modulatory effects of CaMKII are reduced by a peptide that prevents binding to Ca(V)2.1 channels but not by a peptide that blocks catalytic activity, suggesting that binding rather than phosphorylation is responsible for modulation. Our results reveal a signaling complex formed by Ca(V)2.1 channels and CaMKII that regulates P/Q-type Ca(2+) current in neurons. We propose an &quot;effector checkpoint&quot; model for the control of Ca(2+) channel fitness for function that depends on association with CaMKII, SNARE proteins, and other effectors of Ca(2+) signals. This regulatory mechanism would be important in presynaptic nerve terminals, where Ca(V)2.1 channels initiate synaptic transmission and CaMKII has noncatalytic effects on presynaptic plasticity.</p>

Alternate JournalProc. Natl. Acad. Sci. U.S.A.