Gamma-aminobutyric acid type A receptor α subunit (GABA-A receptor α subunit (or GABAAR α subunit))

The Gamma-aminobutyric acid type A receptor α subunit is one of six genetically distinct α subunits (α1–6) that assemble into the GABA-A receptor, a pentameric ligand-gated ion channel responsible for mediating fast inhibitory neurotransmission in the CNS[2][4][5]. Each subunit (~450 amino acids) contains a large extracellular N-terminal domain, four transmembrane helices, and a cytoplasmic loop critical for receptor modulation[1]. The α subunit is required for the benzodiazepine binding site, influences receptor pharmacology and kinetics, and, when combined with β and γ subunits, forms the canonical receptor configuration targeted by many CNS-active drugs[3][6][7]. Dysfunction or altered expression of specific α subunits is implicated in epilepsy, anxiety, insomnia, depression, and neurodevelopmental and neurodegenerative disorders[5][6]. Receptors containing different α subunit isoforms mediate distinct physiological and pharmacological effects and are the focus of subtype-selective drug discovery[4][6].

Other names

GABA-A receptor alpha subunitGABAAR α subunitGABRA (gene family abbreviation; e.g., GABRA1, GABRA2, ...)

Positive allosteric modulation (benzodiazepines, barbiturates, neurosteroids, anesthetics); Negative allosteric modulation (picrotoxin, TBPS); Direct agonism (GABA, gaboxadol); Antagonism (bicuculline, gabazine)