Fast potentiation of glycine receptor channels of intracellular calcium in neurons and transfected cells.
Inhibitory glycine receptors (GlyRs) are mainly expressed in the spinal cord and in the midbrain, where they control motor and sensory pathways. We describe here a fast potentiation of GlyR by intracellular Ca2+. This phenomenon was observed in rat spinal cord neurons and in transfected human cell lines. Potentiation develops in <100 ms, is proportional to Ca2+ influx, and is characterized by an increase in GlyR apparent affinity for glycine. Phosphorylation and G protein pathways appear not to be involved in the potentiation mechanism. Single-channel recordings in cell-attached and excised patches, as well as whole-cell data suggest the presence of a diffusible cytoplasmic factor that modulates the GlyR channel gating properties. Ca2+-induced potentiation may be important for rapid modulation of glycinergic synapses.
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Laboratoire de Biologie Cellulaire et Moléculaire du Neurone, Institut Pasteur, Paris, France.
De Saint Jan
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de Carvalho
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Bregestovski
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D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D005998:Glycine / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism*; D015640:Ion Channel Gating / Q000187:drug effects; D007668:Kidney; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D018091:Receptors, AMPA / Q000378:metabolism; D018009:Receptors, Glycine / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013116:Spinal Cord; D013995:Time; D014162:Transfection
D004791:Enzyme Inhibitors; D018091:Receptors, AMPA; D018009:Receptors, Glycine; D004533:Egtazic Acid; D019204:GTP-Binding Proteins; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium; D005998:Glycine