Abstract
Regulation of neuronal N-methyl-D-aspartate receptors (NMDARs) by protein kinases is critical in synaptic transmission. However, the molecular mechanisms underlying protein kinase C (PKC) potentiation of NMDARs are uncertain. Here we demonstrate that PKC increases NMDA channel opening rate and delivers new NMDA channels to the plasma membrane through regulated exocytosis. PKC induced a rapid delivery of functional NMDARs to the cell surface and increased surface NR1 immunofluorescence in Xenopus oocytes expressing NMDARs. PKC potentiation was inhibited by botulinum neurotoxin A and a dominant negative mutant of soluble NSF-associated protein (SNAP-25), suggesting that receptor trafficking occurs via SNARE-dependent exocytosis. In neurons, PKC induced a rapid delivery of functional NMDARs, assessed by electrophysiology, and an increase in NMDAR clusters on the surface of dendrites and dendritic spines, as indicated by immunofluorescence. Thus, PKC regulates NMDAR channel gating and trafficking in recombinant systems and in neurons, mechanisms that may be relevant to synaptic plasticity.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Botulinum Toxins, Type A / pharmacology
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Cells, Cultured
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Dizocilpine Maleate / pharmacology
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Electrophysiology
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Excitatory Amino Acid Antagonists / pharmacology
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Exocytosis / physiology
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Hippocampus / cytology
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Ion Channel Gating*
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Membrane Proteins*
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Microscopy, Fluorescence
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N-Methylaspartate / pharmacology
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism
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Neuromuscular Agents / pharmacology
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Neurons / cytology
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Neurons / physiology*
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Okadaic Acid / pharmacology
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Oocytes / drug effects
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Oocytes / physiology
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Patch-Clamp Techniques
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Protein Kinase C / chemistry
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Protein Kinase C / metabolism*
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Protein Transport
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Rats
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Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors
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Receptors, N-Methyl-D-Aspartate / genetics
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Receptors, N-Methyl-D-Aspartate / metabolism*
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Synaptosomal-Associated Protein 25
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Tetradecanoylphorbol Acetate / pharmacology
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Xenopus
Substances
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Excitatory Amino Acid Antagonists
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Membrane Proteins
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Nerve Tissue Proteins
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Neuromuscular Agents
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Receptors, N-Methyl-D-Aspartate
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Recombinant Proteins
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Snap25 protein, rat
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Synaptosomal-Associated Protein 25
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Okadaic Acid
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N-Methylaspartate
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Dizocilpine Maleate
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Protein Kinase C
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Botulinum Toxins, Type A
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Tetradecanoylphorbol Acetate