Enables G protein-coupled GABA receptor activity; extracellular matrix protein binding activity; and protein heterodimerization activity. Involved in several processes, including negative regulation of adenylate cyclase activity; neuron-glial cell signaling; and regulation of secretion. Acts upstream of or within adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway. Located in several cellular components, including axolemma; dendrite; and synaptic vesicle. Is integral component of plasma membrane. Part of GABA receptor complex. Is active in GABA-ergic synapse and glutamatergic synapse. Is integral component of postsynaptic membrane and integral component of presynaptic membrane. Used to study visual epilepsy. Biomarker of hypertension and visual epilepsy. Orthologous to human GABBR1 (gamma-aminobutyric acid type B receptor subunit 1). [provided by Alliance of Genome Resources, Apr 2022]