Ligand-Independent G Protein-Coupled Estrogen Receptor/G Protein-Coupled Receptor 30 Activity: Lack of Receptor-Dependent Effects of G-1 and 17-Estradiol.

G protein-coupled receptor 30 (GPR30) is a membrane receptor reported to bind 17-estradiol (E2) and mediate rapid nongenomic estrogen responses, hence also named G protein-coupled estrogen receptor. G-1 is a proposed GPR30-specific agonist that has been used to implicate the receptor in several pathophysiological events. However, controversy surrounds the role of GPR30 in G-1 and E2 responses.