title: The third gamma subunit of the gamma-aminobutyric acid type A receptor family.
abstract: Cloned cDNAs encoding a member of the gamma-aminobutyric acid type A receptor gamma-subunit class were isolated from rat-brain-mRNA-derived libraries. The gamma 3 mRNA is present in cortex, claustrum, caudate putamen, and some thalamic nuclei, particularly the medial geniculate nucleus, where it is the predominant gamma-subunit transcript. The gamma 3 gene is expressed at very low levels in cerebellum and hippocampus. In coexpression experiments with the alpha 1 and beta 2 subunits, gamma 3 imparts benzodiazepine binding to gamma-aminobutyric acid type A receptors and forms gamma-aminobutyric acid-gated benzodiazepine-modulated chloride channels that exhibit a larger conductance than alpha 1 beta 2 receptor channels. Furthermore, the presence of gamma 3 in place of gamma 2 in alpha 1 beta 2 gamma x receptors generates a marked decrease in the affinity of agonists while leaving the affinity of antagonists or negative modulators largely unaffected.
authors.affiliation: Laboratory for Molecular Neuroendocrinology, Zentrum für Molekulare Biologie, ZMBH, Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Herb
authors.forename: W
authors.initials: W
authors.lastname: Wisden
authors.forename: H
authors.initials: H
authors.lastname: Lüddens
authors.forename: G
authors.initials: G
authors.lastname: Puia
authors.forename: S
authors.initials: S
authors.lastname: Vicini
authors.forename: P H
authors.initials: PH
authors.lastname: Seeburg
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001569:Benzodiazepines / Q000494:pharmacology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003001:Cloning, Molecular; D004594:Electrophysiology; D015870:Gene Expression; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011963:Receptors, GABA-A / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000502:physiology
chemical_list: D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011963:Receptors, GABA-A; D001569:Benzodiazepines