. "Combining with the amino acid gamma-aminobutyric acid (GABA, 4-aminobutyrate) and transmitting the signal across the membrane by activating an associated G-protein; promotes the exchange of GDP for GTP on the alpha subunit of a heterotrimeric G-protein complex." . . . "GABA-B receptor activity" . "G-protein coupled GABA receptor activity" . "metabotropic GABA receptor" . . .