G-protein coupled receptor for glutamate. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors. Signaling inhibits adenylate cyclase activity. Interacts with PICK1. Strongly expressed in the cerebellum. Expressed at low levels in hippocampus, hypothalamus and thalamus. No expression detected in liver. Belongs to the G-protein coupled receptor 3 family.