The mouse prostaglandin E receptor EP₂ subtype: cloning, expression, and Northern blot analysis

Abstract

A functional cDNA clone for the mouse prostaglandin (PG) E receptor EP2 subtype was isolated from a mouse cDNA library. The mouse EP2 receptor consists of 362 amino acid residues with seven putative transmembrane domains. [3H]PGE2 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 PGE2 = PGE1 >> iloprost, a stable PGI2 agonist > PGF2 alpha > PGD2. Binding was also inhibited by butaprost (an EP2 agonist) and to a lesser extent by M&B 28767 (an EP3 agonist), but not by sulprostone (an EP1 and EP3 agonist) or SC-19220 (an EP1 antagonist). PGE2 and butaprost increased the cAMP level in the Chinese hamster ovary cells in a concentration-dependent manner. Northern blot analysis revealed that EP2 mRNA is expressed most abundantly in the uterus, followed by the spleen, lung, thymus, ileum, liver, and stomach.