Abstract
Fast synaptic transmission depends on the selective ionic permeability of transmitter-gated ion channels. Here we show changes in the ion selectivity of neuronal P2X transmitter-gated cation channels as a function of time (on the order of seconds) and previous ATP exposure. Heterologously expressed P2X2, P2X2/P2X3 and P2X4 channels as well as native neuronal P2X channels possess various combinations of mono- or biphasic responses and permeability changes, measured by NMDG+ and fluorescent dye. Furthermore, in P2X4 receptors, this ability to alter ion selectivity can be increased or decreased by altering an amino-acid residue thought to line the ion permeation pathway, identifying a region that governs this activity-dependent change.
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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Adenosine Triphosphate / pharmacology*
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Amino Acid Substitution
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Animals
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Benzoxazoles
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Cations / metabolism*
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Cell Membrane Permeability / drug effects
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Cells, Cultured
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DNA, Complementary / genetics
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Fluorescent Dyes / metabolism
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Ion Transport
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Meglumine / metabolism
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Mutagenesis, Site-Directed
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Nerve Tissue Proteins / drug effects
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Nerve Tissue Proteins / physiology*
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Patch-Clamp Techniques
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Quinolinium Compounds
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Rats
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Receptors, Nicotinic / physiology
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Receptors, Purinergic P2 / drug effects
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Receptors, Purinergic P2 / genetics
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Receptors, Purinergic P2 / physiology*
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Receptors, Purinergic P2X2
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Receptors, Purinergic P2X3
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Receptors, Purinergic P2X4
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Recombinant Fusion Proteins / physiology
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Time Factors
Substances
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Benzoxazoles
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Cations
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DNA, Complementary
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Fluorescent Dyes
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Nerve Tissue Proteins
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Quinolinium Compounds
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Receptors, Nicotinic
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Receptors, Purinergic P2
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Receptors, Purinergic P2X2
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Receptors, Purinergic P2X3
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Receptors, Purinergic P2X4
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Recombinant Fusion Proteins
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YO-PRO 1
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Meglumine
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Adenosine Triphosphate