GABRA2
Domain
The extracellular domain contributes to synaptic contact formation.
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:10449790, PubMed:29961870, PubMed:31032849). 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 interfaces (By similarity). When activated by GABA, GABAARs selectively allow the flow of chloride anions across the cell membrane down their electrochemical gradient (PubMed:10449790). Chloride influx into the postsynaptic neuron following GABAAR opening decreases the neuron ability to generate a new action potential, thereby reducing nerve transmission (By similarity). The alpha-2 subunit exhibits synaptogenic activity together with beta-2 and very little to no activity together with beta-3, the gamma-2 subunit being necessary but not sufficient to induce rapid synaptic contacts formation (By similarity).
Involvement in disease
Developmental and epileptic encephalopathy 78
DEE78
A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE78 is an autosomal dominant form characterized by onset of refractory seizures in the first days or months of life. Clinical features include severe developmental delay, hypotonia, microcephaly, cortical visual impairment and profound intellectual disability. Some patients manifest a less severe phenotype characterized by pharmacoresponsive epilepsy, autism spectrum disorder and moderate intellectual disability.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
Glycosylated.
Sequence Similarities
Belongs to the ligand-gated ion channel (TC 1.A.9) family. Gamma-aminobutyric acid receptor (TC 1.A.9.5) subfamily. GABRA2 sub-subfamily.
Cellular localization
- Postsynaptic cell membrane
- Multi-pass membrane protein
- Cell membrane
- Multi-pass membrane protein
- Cytoplasmic vesicle membrane
- Cell projection
- Dendrite
Alternative names
Gamma-aminobutyric acid receptor subunit alpha-2, GABA(A) receptor subunit alpha-2, GABAAR subunit alpha-2, GABRA2