Gamma-aminobutyric acid type A receptor containing gamma-2 subunit (GABA_A receptor gamma-2) (GABRG2-containing GABA_A receptor)

The gamma-aminobutyric acid type A (GABA_A) receptor containing the gamma-2 (γ2) subunit is a pentameric ligand-gated ion channel that serves as the primary mediator of fast inhibitory neurotransmission in the mammalian brain (UniProt P18507). These receptors are predominantly localized at synaptic sites, where they facilitate phasic inhibition by allowing the influx of chloride ions upon GABA binding, thereby hyperpolarizing the postsynaptic neuron (StatPearls: GABA Receptor). The γ2 subunit is uniquely critical for the synaptic clustering of these receptors via interactions with scaffolding proteins like gephyrin and is indispensable for the formation of the benzodiazepine binding site (NCBI Gene: 2566). Dysregulation or mutations in the γ2 subunit are linked to neurological disorders such as childhood absence epilepsy, febrile seizures, and Dravet syndrome (PubMed: 22300236). Pharmacologically, γ2-containing GABA_A receptors are the principal targets for benzodiazepines (e.g., diazepam) and Z-drugs (e.g., zolpidem), which act as positive allosteric modulators to enhance the receptor's response to GABA (Sigel & Steinmann, 2012). Because of their widespread distribution and role in controlling neuronal excitability, they are central to the treatment of anxiety, insomnia, and status epilepticus. Therapeutic challenges include the development of tolerance and physical dependence associated with long-term use of non-selective modulators.

Other names

GABRG2GABA(A) receptor subunit gamma-2Benzodiazepine receptorGamma-2 subunit-containing GABA_A receptorBZD receptor

Positive allosteric modulation of the GABA-induced chloride current; Competitive antagonism at the benzodiazepine binding site.