Abstract
Voltage-gated sodium channels in brain neurons were found to associate with receptor protein tyrosine phosphatase beta (RPTPbeta) and its catalytically inactive, secreted isoform phosphacan, and this interaction was regulated during development. Both the extracellular domain and the intracellular catalytic domain of RPTPbeta interacted with sodium channels. Sodium channels were tyrosine phosphorylated and were modulated by the associated catalytic domains of RPTPbeta. Dephosphorylation slowed sodium channel inactivation, positively shifted its voltage dependence, and increased whole-cell sodium current. Our results define a sodium channel signaling complex containing RPTPbeta, which acts to regulate sodium channel modulation by tyrosine phosphorylation.
Publication types
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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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Binding Sites
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Brain / cytology
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Carbonic Anhydrases / chemistry
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Catalytic Domain
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Cell Line
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Cell Membrane / metabolism
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Chondroitin Sulfate Proteoglycans / chemistry
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Chondroitin Sulfate Proteoglycans / metabolism
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Electric Conductivity
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Humans
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Ion Channel Gating*
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Nerve Tissue Proteins / antagonists & inhibitors
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Nerve Tissue Proteins / chemistry
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Nerve Tissue Proteins / metabolism*
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Neurons / cytology
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Neurons / metabolism
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Phosphorylation
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Phosphotyrosine / metabolism
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Precipitin Tests
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Protein Binding
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Protein Isoforms / chemistry
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Protein Isoforms / metabolism
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Protein Tyrosine Phosphatases / antagonists & inhibitors
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Protein Tyrosine Phosphatases / chemistry
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Protein Tyrosine Phosphatases / metabolism*
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Rats
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Receptor-Like Protein Tyrosine Phosphatases, Class 5
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Sodium / metabolism
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Sodium Channels / chemistry
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Sodium Channels / genetics
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Sodium Channels / metabolism*
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Transfection
Substances
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Chondroitin Sulfate Proteoglycans
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Nerve Tissue Proteins
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Protein Isoforms
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Recombinant Fusion Proteins
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Sodium Channels
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Phosphotyrosine
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Sodium
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PTPRZ1 protein, human
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Protein Tyrosine Phosphatases
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Ptprz1 protein, rat
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Receptor-Like Protein Tyrosine Phosphatases, Class 5
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Carbonic Anhydrases