Enables estradiol binding activity and estrogen receptor activity. Involved in several processes, including apoptotic nuclear changes; cellular response to organic cyclic compound; and positive regulation of signal transduction. Acts upstream of with a positive effect on vasodilation. Located in several cellular components, including dendrite; postsynaptic density; and presynaptic membrane. Orthologous to human GPER1 (G protein-coupled estrogen receptor 1). [provided by Alliance of Genome Resources, Apr 2022]