Abstract
RNA editing and subunit assembly of ionotropic glutamate receptors (GluRs) were examined in an oligodendrocyte progenitor cell line, CG4, which expresses GluR2-GluR4, GluR6, GluR7, KA1, and KA2. AMPA-evoked currents rapidly desensitize, whereas kainate-evoked currents contain a steady-state component with a nearly linear current-voltage relation and a fast desensitizing component that is inwardly rectifying. The Q/R site is edited > 95% to the arginine codon in GluR2(Q607) mRNA, and < 5% in GluR6(Q621) mRNA. Immunoprecipitation experiments demonstrate that GluR6 and/or GluR7 subunits assemble with KA2, but not with GluR2-GluR4. These results indicate that oligodendrocyte progenitor cells selectively edit and assemble glutamate receptors into at least two functionally and structurally distinct heteromeric channels.
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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Arginine
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Base Sequence
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Cell Line
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Cerebral Cortex / cytology
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Codon
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Electric Conductivity
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Glutamates / pharmacology
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Glutamic Acid
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Humans
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Immunosorbent Techniques
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Ion Channels / drug effects
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Ion Channels / physiology
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Kainic Acid / pharmacology
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Molecular Sequence Data
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Oligodendroglia / drug effects
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Oligodendroglia / physiology*
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Polymerase Chain Reaction
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RNA / chemistry
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RNA Editing*
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RNA Splicing
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Rats
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Receptors, Glutamate / genetics*
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Receptors, Glutamate / physiology
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Stem Cells / physiology
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / pharmacology
Substances
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Codon
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Glutamates
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Ion Channels
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Receptors, Glutamate
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Glutamic Acid
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RNA
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alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
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Arginine
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Kainic Acid