The mouse prostaglandin E receptor EP sub(2) subtype: Cloning, expression, and Northern blot analysis

A functional cDNA clone for the mouse prostaglandin (PG) E receptor EP sub(2) subtype was isolated from a mouse cDNA library. The mouse EP sub(2) receptor consists of 362 amino acid residues with seven putative transmembrane domains. [ super(3)H]PGE sub(2) bound specifically to the membrane of Chinese hamster ovary cells stably expressing the cloned receptor. This binding was displaced by unlabeled prostanoids in the order of PGE sub(2) = PGE sub(1) >> iloprost, a stable PGI sub(2) agonist > PGF sub(2 alpha ) > PGD sub(2). Binding was also inhibited by butaprost (an EP sub(2) agonist) and to a lesser extent by M&B 28767 (an EP sub(3) agonist), but not by sulprostone (an EP sub(1) and EP sub(3) agonist) or SC-19220 (an EP sub(1) antagonist). PGE sub(2) and butaprost increased the cAMP level in the Chinese hamster ovary cells in a concentration-dependent manner. Northern blot analysis revealed that EP sub(2) mRNA is expressed most abundantly in the uterus, followed by the spleen, lung, thymus, ileum, liver, and stomach.