Page last updated: 2024-10-24

G protein-coupled GABA receptor complex

Definition

Target type: cellularcomponent

A protein complex which is capable of G protein-coupled GABA receptor activity. In human, it is usually a heterodimer composed of GABA-B receptor subunits 1 and 2. [GO_REF:0000088, GOC:bhm, GOC:TermGenie, PMID:18790874]

The G protein-coupled GABA receptor complex is a multi-protein assembly that mediates the inhibitory effects of the neurotransmitter GABA. It is comprised of the GABA receptor itself, which is a pentameric ion channel composed of various subunits, and a G protein. The cellular component of this complex can be described as follows:

* **Plasma membrane:** The GABA receptor complex is localized to the plasma membrane of neurons, specifically at synapses. This localization allows it to directly interact with GABA released from presynaptic neurons.

* **Extracellular domain:** The GABA receptor subunits have extracellular domains that bind GABA. This binding triggers a conformational change in the receptor, leading to the opening of its ion channel.

* **Transmembrane domain:** The GABA receptor subunits also have transmembrane domains that span the plasma membrane. These domains are responsible for forming the ion channel pore that allows the passage of chloride ions into the neuron.

* **Cytoplasmic domain:** The GABA receptor subunits have cytoplasmic domains that interact with intracellular signaling molecules, including G proteins.

* **G protein:** The G protein is a heterotrimeric protein that is associated with the cytoplasmic domain of the GABA receptor. Upon activation by the GABA receptor, the G protein dissociates into its alpha, beta, and gamma subunits. The alpha subunit can then activate downstream signaling pathways, ultimately leading to the inhibition of neuronal activity.

* **Scaffolding proteins:** Various scaffolding proteins can associate with the GABA receptor complex, contributing to its stability and localization. These proteins can also link the complex to other signaling pathways, further modulating its function.

The precise composition and organization of the G protein-coupled GABA receptor complex can vary depending on the specific neuronal subtype and the presence of different receptor subunits. However, the fundamental components of this complex, including the GABA receptor, G protein, and associated scaffolding proteins, are essential for its function in mediating GABAergic neurotransmission.'
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Proteins (2)

ProteinDefinitionTaxonomy
Gamma-aminobutyric acid type B receptor subunit 1A gamma-aminobutyric acid type B receptor subunit 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9UBS5]Homo sapiens (human)
Gamma-aminobutyric acid type B receptor subunit 2A gamma-aminobutyric acid type B receptor subunit 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O75899]Homo sapiens (human)

Compounds (13)

CompoundDefinitionClassesRoles
gamma-aminobutyric acidgamma-aminobutyric acid : A gamma-amino acid that is butanoic acid with the amino substituent located at C-4.

gamma-Aminobutyric Acid: The most common inhibitory neurotransmitter in the central nervous system.
amino acid zwitterion;
gamma-amino acid;
monocarboxylic acid
human metabolite;
neurotransmitter;
Saccharomyces cerevisiae metabolite;
signalling molecule
baclofenamino acid zwitterion;
gamma-amino acid;
monocarboxylic acid;
monochlorobenzenes;
primary amino compound
central nervous system depressant;
GABA agonist;
muscle relaxant
(1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid(1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid: a GABA-C receptor antagonist; structure in first source
vigabatringamma-amino acidanticonvulsant;
EC 2.6.1.19 (4-aminobutyrate--2-oxoglutarate transaminase) inhibitor
4-amino-3-phenylbutyric acid4-amino-3-phenylbutyric acid: phenyl deriv of GABA; RN given refers to cpd without isomeric designation; structureorganonitrogen compound;
organooxygen compound
Arbaclofenorganonitrogen compound;
organooxygen compound
4-amino-3-(5-chloro-2-thienyl)butyric acid4-amino-3-(5-chloro-2-thienyl)butyric acid: binds GABA receptors; RN & structure given in first source
alpha-ethyl, alpha-methyl-thiobutyrolactonetetrahydrothiophenes
cgp 36742(3-aminopropyl)(n-butyl)phosphinic acid: interacts preferably with GABA-B RECEPTORS (IC50=38 μM) and GABA-C receptors (IC50=62 μM) over GABA-A RECEPTORS (IC50=508 μM)
alpha-isopropyl-alpha-methyl-gamma-butyrolactonealpha-isopropyl-alpha-methyl-gamma-butyrolactone: structure given in first source; picrotoxin receptor antagonist
(r,s)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3h-benzofuran-2-one(R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one: a positive allosteric modulator of GABAB receptors; structure in first source
cgp 79302,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl)phenol: structure in first sourcealkylbenzene
n,n'-dicyclopentyl-2-methylsulfanyl-5-nitro-pyrimidine-4,6-diamineN,N'-dicyclopentyl-2-methylsulfanyl-5-nitro-pyrimidine-4,6-diamine: structure in first sourcearyl sulfide