Abstract
Voltage-gated Ca(2+) channels (VGCCs) are important in regulating a variety of cellular functions in neurons. It remains poorly understood how VGCCs with different functions are sorted within neurons. Here we show that the t-complex testis-expressed 1 (tctex1) protein, a light-chain subunit of the dynein motor complex, interacts directly and selectively with N- and P/Q-type Ca(2+) channels, but not L-type Ca(2+) channels. The interaction is insensitive to Ca(2+). Overexpression in hippocampal neurons of a channel fragment containing the binding domain for tctex1 significantly decreases the surface expression of endogenous N- and P/Q-type Ca(2+) channels but not L-type Ca(2+) channels, as determined by immunostaining. Furthermore, disruption of the tctex1-Ca(2+) channel interaction significantly reduces the Ca(2+) current density in hippocampal neurons. These results underscore the importance of the specific tctex1-channel interaction in determining sorting and trafficking of neuronal Ca(2+) channels with different functionalities.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Blotting, Western / methods
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Calcium / pharmacology
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Calcium Channels / chemistry
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Calcium Channels / classification
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Calcium Channels / metabolism*
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Carbodiimides / metabolism
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Carbodiimides / pharmacology
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Cells, Cultured
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Dose-Response Relationship, Drug
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Dyneins
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Electric Capacitance
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Electron Spin Resonance Spectroscopy / methods
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Embryo, Mammalian
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Enzyme Inhibitors / pharmacology
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Gene Expression
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Gene Expression Regulation / drug effects
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Gene Expression Regulation / physiology*
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Green Fluorescent Proteins / metabolism
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Hippocampus / cytology
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Immunohistochemistry / methods
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Immunoprecipitation / methods
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Ion Channel Gating
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Membrane Potentials / radiation effects
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Microtubule-Associated Proteins / metabolism*
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Molecular Sequence Data
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Mutagenesis / physiology
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Neurons / metabolism*
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Nuclear Proteins / metabolism*
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Patch-Clamp Techniques / methods
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Rats
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Recombinant Fusion Proteins / metabolism
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Time Factors
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Transfection / methods
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Two-Hybrid System Techniques
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t-Complex Genome Region
Substances
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Calcium Channels
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Carbodiimides
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Dynlt1 protein, rat
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Enzyme Inhibitors
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Microtubule-Associated Proteins
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Nuclear Proteins
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Recombinant Fusion Proteins
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Green Fluorescent Proteins
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N-cyclohexyl-N'-(4-dimethylamino-alpha-naphthyl)carbodiimide
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Dyneins
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Calcium
Associated data
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GENBANK/M94172
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GENBANK/X15539
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GENBANK/X57477
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RefSeq/NM_031318