Molecular diversity of prostanoid receptors; subtypes and isoforms of prostaglandin E receptor.

cDNA cloning of PGE receptors revealed that there are at least three distinct subtypes of the receptor derived from different genes, which are different in ligand binding character and signal transduction. They also distribute differently in the body and localize in different cells of the organ. The cloning study also revealed that multiple isoforms of EP3 are produced by alternative splicing of its mRNA, and that these isoforms show identical ligand binding properties but couple to different signal transduction pathways. Thus, our study has shown that the diversity of PGE actions in the body is elicited by the molecular diversity of its receptor mediating these responses.