Gamma-aminobutyric acid receptor type B subunit 1 (GABAB1 or GABBR1)

Gamma-aminobutyric acid receptor type B subunit 1 (GABAB1/GABBR1) is one of two principal subunits forming the heterodimeric GABAB receptor, a class C G protein-coupled receptor that mediates the slow, prolonged inhibitory effects of the major CNS neurotransmitter gamma-aminobutyric acid (GABA). The GABAB1 subunit is responsible for binding endogenous and pharmacological ligands, while coupling to G protein signaling occurs via the GABAB2 subunit. GABAB receptors are widely distributed in the brain and some peripheral tissues, where they modulate neuronal excitability, neurotransmitter release, and various physiological processes including sleep, muscle relaxation, and pain perception. Dysfunction or dysregulation of GABAB signaling has been implicated in several CNS diseases and as a therapeutic target in epilepsy, addiction, pain, and other neurological disorders. Drugs that influence GABAB receptor activity have important roles in clinical therapeutics and research.

Other names

GABAB1GABBR1gamma-aminobutyric acid type B receptor subunit 1GABA-B receptor 1

Activation by agonists (e.g., baclofen) leads to inhibition of adenylyl cyclase, activation of K+ channels, inhibition of Ca2+ channels, reduction of neurotransmitter release, and postsynaptic hyperpolarization. Antagonists block these inhibitory effects. Positive allosteric modulators enhance efficacy of endogenous agonists.