Gamma-aminobutyric acid (GABA) B receptor, 2 (GABAB2) is a G-protein coupled receptor subunit encoded by the GABBR2 gene in humans. [5]
B-type receptors for the neurotransmitter GABA (gamma-aminobutyric acid) inhibit neuronal activity through G protein-coupled second-messenger systems, which regulate the release of neurotransmitters and the activity of ion channels and adenylyl cyclase. See GABBR1 (MIM 603540) for additional background information on GABA-B receptors.[supplied by OMIM] [5]
The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid (GABA), the chief inhibitory compound in the mature vertebrate central nervous system. There are two classes of GABA receptors: GABAA and GABAB. GABAA receptors are ligand-gated ion channels ; whereas GABAB receptors are G protein-coupled receptors, also called metabotropic receptors.
GABAB receptors (GABABR) are G-protein coupled receptors for gamma-aminobutyric acid (GABA), therefore making them metabotropic receptors, that are linked via G-proteins to potassium channels. The changing potassium concentrations hyperpolarize the cell at the end of an action potential. The reversal potential of the GABAB-mediated IPSP is –100 mV, which is much more hyperpolarized than the GABAA IPSP. GABAB receptors are found in the central nervous system and the autonomic division of the peripheral nervous system.
The GABAA-rho receptor is a subclass of GABAA receptors composed entirely of rho (ρ) subunits. GABAA receptors including those of the ρ-subclass are ligand-gated ion channels responsible for mediating the effects of gamma-amino butyric acid (GABA), the major inhibitory neurotransmitter in the brain. The GABAA-ρ receptor, like other GABAA receptors, is expressed in many areas of the brain, but in contrast to other GABAA receptors, the GABAA-ρ receptor has especially high expression in the retina.
Gamma-aminobutyric acid B receptor, 1 (GABAB1), is a G-protein coupled receptor subunit encoded by the GABBR1 gene.
Gamma-aminobutyric acid receptor subunit gamma-2 is a protein that in humans is encoded by the GABRG2 gene.
Gamma-aminobutyric acid receptor subunit alpha-1 is a protein that in humans is encoded by the GABRA1 gene.
Gamma-aminobutyric acid receptor subunit beta-3 is a protein that in humans is encoded by the GABRB3 gene. It is located within the 15q12 region in the human genome and spans 250kb. This gene includes 10 exons within its coding region. Due to alternative splicing, the gene codes for many protein isoforms, all being subunits in the GABAA receptor, a ligand-gated ion channel. The beta-3 subunit is expressed at different levels within the cerebral cortex, hippocampus, cerebellum, thalamus, olivary body and piriform cortex of the brain at different points of development and maturity. GABRB3 deficiencies are implicated in many human neurodevelopmental disorders and syndromes such as Angelman syndrome, Prader-Willi syndrome, nonsyndromic orofacial clefts, epilepsy and autism. The effects of methaqualone and etomidate are mediated through GABBR3 positive allosteric modulation.
Gamma-aminobutyric acid receptor subunit beta-1 is a protein that in humans is encoded by the GABRB1 gene.
Gamma-aminobutyric acid receptor subunit rho-1 is a protein that in humans is encoded by the GABRR1 gene.
Gamma-aminobutyric acid receptor subunit alpha-6 is a protein that in humans is encoded by the GABRA6 gene.
Gamma-aminobutyric acid (GABA) A receptor, alpha 5, also known as GABRA5, is a protein which in humans is encoded by the GABRA5 gene.
Gamma-aminobutyric acid receptor subunit epsilon is a protein that in humans is encoded by the GABRE gene.
Gamma-aminobutyric acid receptor subunit alpha-4 is a protein that in humans is encoded by the GABRA4 gene.
Gamma-aminobutyric acid receptor subunit rho-2 is a protein that in humans is encoded by the GABRR2 gene.
GABAA receptor-γ3, also known as GABRG3, is a protein which in humans is encoded by the GABRG3 gene.
Gamma-aminobutyric acid receptor subunit delta is a protein that in humans is encoded by the GABRD gene.
Gamma-aminobutyric acid receptor subunit pi is a protein that in humans is encoded by the GABRP gene.
Gamma-aminobutyric acid receptor subunit gamma-1 is a protein that in humans is encoded by the GABRG1 gene. The protein encoded by this gene is a subunit of the GABAA receptor.
Gamma-aminobutyric acid receptor subunit theta is a protein that in humans is encoded by the GABRQ gene. The protein encoded by this gene is a subunit of the GABAA receptor.
Gamma-aminobutyric acid receptor subunit rho-3 is a protein that in humans is encoded by the GABRR3 gene. The protein encoded by this gene is a subunit of the GABAA-ρ receptor.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.