Enables cholesterol binding activity; glutamate binding activity; and group II metabotropic glutamate receptor activity. Involved in several processes, including G protein-coupled glutamate receptor signaling pathway; learning or memory; and synapse organization. Located in membrane raft and plasma membrane. Is expressed in several structures, including adult central brain intrinsic neurons; ellipsoid body layer; ganglia; neuromere; and synaptic neuropil domain. Orthologous to several human genes including GRM3 (glutamate metabotropic receptor 3).