GABRB2

Description

The GABRB2 (gamma-aminobutyric acid type A receptor subunit beta2) is a protein-coding gene located on chromosome 5.

The GABAA beta-2 subunit is a protein that in humans is encoded by the GABRB2 gene. It combines with other subunits to form the ionotropic GABAA receptors. GABA (γ-aminobutyric acid) system is the major inhibitory system in the brain, and its dominant GABAA receptor subtype is composed of α1, β2, and γ2 subunits with the stoichiometry of 2:2:1, which accounts for 43% of all GABAA receptors. Alternative splicing of the GABRB2 gene leads at least to four isoforms, viz. β2-long (β2L) and β2-short (β2S, β2S1, and β2S2). Alternatively spliced variants displayed similar but non-identical electrophysiological properties. GABRB2 is subjected to positive selection and known to be both an alternative splicing and a recombination hotspot; it is regulated via epigenetic regulation including imprinting and gene and promoter methylation. GABRB2 has been associated with a number of neuropsychiatric disorders, and found to display altered expression in cancer. == Structure == GABRB2 encodes the GABAA receptor beta-2 subunit. It is highly expressed in the brain with dominance in the gray matter. In humans, it is located on chromosome 5q34, with 11 exons and 10 introns spanning more than 260 kb, and a promoter region ranging from 1000 bp upstream to 689 bp downstream of exon 1.

Ligand-gated chloride channel that is a component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the brain. Plays a significant role in the formation of functional inhibitory GABAergic synapses, in addition to mediating synaptic inhibition as a GABA-gated ion channel. The gamma2 subunit is necessary but not sufficient for rapid formation of active synaptic contacts, and the synaptogenic effect of this subunit is influenced by the type of alpha and beta subunits present in the receptor pentamer. The alpha1/beta2/gamma2 receptor and the alpha2/beta2/gamma2 receptor exhibit synaptogenic activity. Also functions as a histamine receptor and mediates cellular responses to histamine.

GABRB2 is also known as DEE92, ICEE2.

Associated Diseases

• Epileptic encephalopathy, infantile or early childhood, 2
• Non-specific early-onset epileptic encephalopathy