Molecular cloning and expression of rat prostaglandin E receptor EP2 subtype.

A cDNA clone encoding the rat prostaglandin (PG) E receptor EP2 subtype was cloned from a rat lung cDNA library. It encodes 488 amino acid residues with putative seven-transmembrane domains. Specific binding of [3H]PGE2 was found in COS-7 cells transfected with the cDNA and was displaced with unlabeled prostaglandins in the order of PGE2 = PGE1 >> iloprost > or = PGF2 alpha > or = PGD2. The binding was also inhibited by misoprostol, an EP2 and EP3 agonist, but not by sulprostone, an EP1 and EP3 agonist. Northern blot analysis demonstrated that the EP2 mRNA is widely expressed in various tissues, the significant expression being observed in the thymus, lung, spleen, heart stomach, and pancreas.