GABRA4
Domain
The GABA-binding pockets are located at the interface between neighboring alpha and beta subunits.
GABAARs subunits share a common topological structure: a peptide sequence made up of a long extracellular N-terminal, four transmembrane domains, intracellular or cytoplasmic domain located between the third and the fourth transmembrane domains.
Function
Alpha subunit of the heteropentameric ligand-gated chloride channel gated by gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the brain (PubMed:35355020). GABA-gated chloride channels, also named GABA(A) receptors (GABAAR), consist of five subunits arranged around a central pore and contain GABA active binding site(s) located at the alpha and beta subunit interface(s) (PubMed:35355020). When activated by GABA, GABAARs selectively allow the flow of chloride anions across the cell membrane down their electrochemical gradient (PubMed:35355020). GABAARs containing alpha-4 are predominantly extrasynaptic, contributing to tonic inhibition in dentate granule cells and thalamic relay neurons (By similarity). Extrasynaptic alpha-4-containing GABAARs control levels of excitability and network activity (By similarity). GABAAR containing alpha-4-beta-3-delta subunits can simultaneously bind GABA and histamine where histamine binds at the interface of two neighboring beta subunits, which may be involved in the regulation of sleep and wakefulness (PubMed:35355020).
Sequence Similarities
Belongs to the ligand-gated ion channel (TC 1.A.9) family. Gamma-aminobutyric acid receptor (TC 1.A.9.5) subfamily. GABRA4 sub-subfamily.
Tissue Specificity
Expressed in the brain.
Cellular localization
- Cell membrane
- Multi-pass membrane protein
- Postsynaptic cell membrane
- Multi-pass membrane protein
Alternative names
Gamma-aminobutyric acid receptor subunit alpha-4, GABA(A) receptor subunit alpha-4, GABAAR subunit alpha-4, GABRA4