Transient expression shows ligand gating and allosteric potentiation of GABAA receptor subunits.
Human gamma-aminobutyric acid A (GABAA) receptor subunits were expressed transiently in cultured mammalian cells. This expression system allows the simultaneous characterization of ligand-gated ion channels by electrophysiology and by pharmacology. Thus, coexpression of the alpha and beta subunits of the GABAA receptor generated GABA-gated chloride channels and binding sites for GABAA receptor ligands. Channels consisting of only alpha or beta subunits could also be detected. These homomeric channels formed with reduced efficiencies compared to the heteromeric receptors. Both of these homomeric GABA-responsive channels were potentiated by barbiturate, indicating that sites for both ligand-gating and allosteric potentiation are present on receptors assembled from either subunit.
Pritchett
D B
DB
Laboratory of Molecular Neuroendocrinology, ZMBH, University of Heidelberg, Federal Republic of Germany.
Sontheimer
H
H
Gorman
C M
CM
Kettenmann
H
H
Seeburg
P H
PH
Schofield
P R
PR
D000494:Allosteric Regulation; D015152:Blotting, Northern; D002478:Cells, Cultured; D018118:Chloride Channels; D002712:Chlorides / Q000502:physiology*; D003001:Cloning, Molecular; D004553:Electric Conductivity; D006801:Humans; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000502:physiology*; D009118:Muscimol / Q000378:metabolism; D011963:Receptors, GABA-A / Q000502:physiology* / Q000648:ultrastructure; D013329:Structure-Activity Relationship; D014162:Transfection
D018118:Chloride Channels; D002712:Chlorides; D046911:Macromolecular Substances; D008565:Membrane Proteins; D011963:Receptors, GABA-A; D009118:Muscimol