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 TAMALIN (By similarity). Interacts with HTR2A. Detected in neurons in brain cortex (at protein level). Belongs to the G-protein coupled receptor 3 family.