Abstract
Inactivation of presynaptic Ca(V)2.2 channels may play a role in regulating short-term synaptic plasticity. Here, we report a direct modulation of Ca(V)2.2 channel inactivation properties by 14-3-3, a family of signaling proteins involved in a wide range of biological processes. The structural elements critical for 14-3-3 binding and channel modulation lie in the carboxyl tail of the pore-forming alpha(1B) subunit, where we have identified two putative 14-3-3 interaction sites, including a phosphoserine-containing motif that directly binds to 14-3-3 and a second region near the EF hand and IQ domain. In transfected tsA 201 cells, 14-3-3 coexpression dramatically slows open-state inactivation and reduces cumulative inactivation of Ca(V)2.2 channels. In hippocampal neurons, interference with 14-3-3 binding accelerates Ca(V)2.2 channel inactivation and enhances short-term synaptic depression. These results demonstrate that 14-3-3 proteins are important regulators of Ca(V)2.2 channel activities and through this mechanism may contribute to their regulation of synaptic transmission and plasticity.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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14-3-3 Proteins / genetics
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14-3-3 Proteins / metabolism
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14-3-3 Proteins / physiology*
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Amino Acid Sequence
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Animals
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Binding Sites / genetics
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Binding, Competitive
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Blotting, Western
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Brain / cytology
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Brain / metabolism*
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Calcium Channels, L-Type / genetics
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Calcium Channels, L-Type / metabolism
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Calcium Channels, N-Type / genetics
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Calcium Channels, N-Type / metabolism*
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Calcium Channels, T-Type / genetics
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Calcium Channels, T-Type / metabolism
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Cell Line
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Cells, Cultured
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Glutathione Transferase / genetics
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Glutathione Transferase / metabolism
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Humans
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Neurons / cytology
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Neurons / metabolism
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Phosphorylation
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Protein Binding
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Protein Subunits / genetics
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Protein Subunits / metabolism
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Rats
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Rats, Sprague-Dawley
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Synaptic Transmission / physiology
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Time Factors
Substances
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14-3-3 Proteins
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Calcium Channels, L-Type
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Calcium Channels, N-Type
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Calcium Channels, T-Type
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L-type calcium channel alpha(1C)
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Protein Subunits
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Recombinant Fusion Proteins
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Glutathione Transferase