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. May mediate suppression of neurotransmission or may be involved in synaptogenesis or synaptic stabilization. Interacts with HTR2A (By similarity). Interacts with TAMALIN. Is widely distributed in the CNS and prominent expression is seen in Golgi cells of the cerebellum and some particular neuronal cells in other brain regions. Belongs to the G-protein coupled receptor 3 family.