Enables G protein-coupled receptor activity involved in regulation of postsynaptic membrane potential and estrogen receptor binding activity. Involved in several processes, including G protein-coupled glutamate receptor signaling pathway; calcium-mediated signaling; and regulation of glutamatergic synaptic transmission. Located in axon; dendritic spine; and synaptic membrane. Is active in glutamatergic synapse. Is integral component of postsynaptic density membrane. Biomarker of temporal lobe epilepsy. Human ortholog(s) of this gene implicated in autosomal recessive spinocerebellar ataxia 13 and spinocerebellar ataxia 44. Orthologous to human GRM1 (glutamate metabotropic receptor 1). [provided by Alliance of Genome Resources, Apr 2022]