title: Stoichiometry of a recombinant GABAA receptor deduced from mutation-induced rectification.
abstract: Ligand-gated ion channels generally display a heterooligomeric subunit structure. The present report describes an electrophysiological method that provides criteria indicating the subunit stoichiometry of a recombinant GABAA receptor composed of alpha 3, beta 2 and gamma 2 subunits. Our results exclude the stoichiometries 3 alpha 1 beta 1 gamma, 1 alpha 3 beta 1 gamma, 1 alpha 1 beta 3 gamma and suggest that the possible subunit stoichiometries for this receptor are 2 alpha 1 beta 2 gamma, 2 alpha 2 beta 1 gamma or 1 alpha 2 beta 2 gamma, of which the alpha subunit composition 2 alpha 1 beta 2 gamma may be favoured. The method is based on the quantification of the outward rectification of the GABA-evoked current induced by point mutation of charged amino acids located near the ion channel pore.
authors.affiliation: Institute of Pharmacology, University of Zürich, Switzerland.
authors.forename: K H
authors.initials: KH
authors.lastname: Backus
authors.forename: M
authors.initials: M
authors.lastname: Arigoni
authors.forename: U
authors.initials: U
authors.lastname: Drescher
authors.forename: L
authors.initials: L
authors.lastname: Scheurer
authors.forename: P
authors.initials: P
authors.lastname: Malherbe
authors.forename: H
authors.initials: H
authors.lastname: Möhler
authors.forename: J A
authors.initials: JA
authors.lastname: Benson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004594:Electrophysiology; D006801:Humans; D007473:Ion Channels / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D051381:Rats; D011963:Receptors, GABA-A / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics
chemical_list: D007473:Ion Channels; D011963:Receptors, GABA-A; D011994:Recombinant Proteins