The function of Ensembl gene identifier ENSG00000164082 (GRM2, glutamate metabotropic receptor 2) is as follows. Dimeric G protein-coupled receptor which is activated by the excitatory neurotransmitter L-glutamate (PubMed:37286794). Plays critical roles in modulating synaptic transmission and neuronal excitability. Upon activation by glutamate, inhibits presynaptic calcium channels, reducing further glutamate release and dampening excitatory signaling (By similarity). Mechanistically, ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors, such as adenylate cyclase. May mediate suppression of neurotransmission or may be involved in synaptogenesis or synaptic stabilization. {ECO:0000250|UniProtKB:Q14BI2, ECO:0000269|PubMed:18297054, ECO:0000269|PubMed:22300836, ECO:0000269|PubMed:23129762, ECO:0000269|PubMed:37286794, ECO:0000269|PubMed:7620613}. (Microbial infection) Plays an important role in influenza virus internalization. . (Microbial infection) Acts as a host entry factor for rabies virus that hijacks the endocytosis of GRM2 to enter cells. . (Microbial infection) Acts as a host entry factor for SARS- CoV-2 that hijacks the endocytosis of GRM2 to enter cells. .