Abstract
Myosin VI is an actin-based motor protein that is enriched at the postsynaptic density and appears to interact with alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate-type glutamate receptors (AMPARs) via synapse associated protein 97 (SAP97). Here, we find that a Flag epitope-tagged dominant negative construct that inhibits the interaction between SAP97 and myosin VI (Flag-myoVI-DN) causes a dramatic reduction in the number of synapses and the surface expression of AMPARs in cultured hippocampal neurons. Furthermore, we find that Flag-myoVI-DN also prevents the rapid delivery of AMPARs to synapses that can be induced by the transient activation of N-methyl-d-aspartate receptors. The Flag-myoVI-DN induced decrease in surface AMPARs is not because of reduced AMPAR subunit protein synthesis. Using whole-cell recording, we show that Flag-myoVI-DN also prevents the activity-induced increase in miniature excitatory postsynaptic current frequency that is normally associated with recruitment of AMPARs to the cell surface at synaptic sites that lack these receptors (i.e. 'silent' synapses). Together, these results indicate that myosin VI/SAP97 plays an important role in trafficking and activity-dependent recruitment of AMPARs to synapses.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing / genetics
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Adaptor Proteins, Signal Transducing / metabolism*
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Aminoquinolines / pharmacology
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Animals
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Animals, Newborn
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Carcinoma / pathology
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Cells, Cultured
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Discs Large Homolog 1 Protein
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Excitatory Amino Acid Antagonists / pharmacology
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Excitatory Postsynaptic Potentials / drug effects
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Excitatory Postsynaptic Potentials / physiology
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Hippocampus / cytology*
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Humans
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Myosin Heavy Chains / genetics
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Myosin Heavy Chains / metabolism*
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Neurons / cytology
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Patch-Clamp Techniques / methods
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Potassium Chloride / pharmacology
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Protein Structure, Tertiary / physiology
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Protein Subunits / genetics
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Protein Subunits / metabolism
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Protein Transport / physiology
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Rats
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Receptors, AMPA / metabolism*
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Synapses / drug effects
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Synapses / metabolism*
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Transfection / methods
Substances
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Adaptor Proteins, Signal Transducing
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Aminoquinolines
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DLG1 protein, human
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Discs Large Homolog 1 Protein
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Excitatory Amino Acid Antagonists
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Membrane Proteins
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Protein Subunits
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Receptors, AMPA
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myosin VI
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4-trans-2-carboxy-5,7-dichloro-4-phenylaminocarbonylamino-1,2,3,4-tetrahydroquinoline
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Green Fluorescent Proteins
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Potassium Chloride
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Myosin Heavy Chains