THE MOUSE PROSTAGLANDIN-E RECEPTOR EP(2) SUBTYPE - CLONING, EXPRESSION, AND NORTHERN BLOT ANALYSIS

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