| Primary Identifier | IPR001923 | Type | Family |
| Short Name | Prostglndn_EP2_rcpt |
| description | G protein-coupled receptors (GPCRs) constitute a vast protein family that encompasses a wide range of functions, including various autocrine, paracrine and endocrine processes. They show considerable diversity at the sequence level, on the basis of which they can be separated into distinct groups []. The term clan can be used to describe the GPCRs, as they embrace a group of families for which there are indications of evolutionary relationship, but between which there is no statistically significant similarity in sequence []. The currently known clan members include rhodopsin-like GPCRs (Class A, GPCRA), secretin-like GPCRs (Class B, GPCRB), metabotropic glutamate receptor family (Class C, GPCRC), fungal mating pheromone receptors (Class D, GPCRD), cAMP receptors (Class E, GPCRE) and frizzled/smoothened (Class F, GPCRF) [, , , , ]. GPCRs are major drug targets, and are consequently the subject of considerable research interest. It has been reported that the repertoire of GPCRs for endogenous ligands consists of approximately 400 receptors in humans and mice []. Most GPCRs are identified on the basis of their DNA sequences, rather than the ligand they bind, those that are unmatched to known natural ligands are designated by as orphan GPCRs, or unclassified GPCRs [].The rhodopsin-like GPCRs (GPCRA) represent a widespread protein family that includes hormone, neurotransmitter and light receptors, all of which transduce extracellular signals through interaction with guanine nucleotide-binding (G) proteins. Although their activating ligands vary widely in structure and character, the amino acid sequences of the receptors are very similar and are believed to adopt a common structural framework comprising 7 transmembrane (TM) helices [, , ].Prostanoids (prostaglandins (PG) and thromboxanes (TX)) mediate a wide variety of actions and play important physiological roles in the cardiovascular and immune systems, and in pain sensation in peripheral systems. PGI2 and TXA2 have opposing actions, involving regulation of the interaction of platelets with the vascular endothelium, while PGE2, PGI2 and PGD2 are powerful vasodilators and potentiate the action of various autocoids to induce plasma extravasation and pain sensation. To date, evidence for at least 5 classes of prostanoid receptor has been obtained. However, identification of subtypes and their distribution is hampered by expression of more than one receptor within a tissue, coupled with poor selectivity of available agonists and antagonists.Prostaglandin E2 receptor EP2, also called prostanoid EP2 receptor, is one of fourreceptor subtypes whose endogenous physiological ligand is prostaglandin E2 (PGE2). Stimulation of the EP2 receptor by PGE2 causes cAMP accumulation through G(s) protein activation, which subsequently produces smooth muscle relaxation and mediates the systemic vasodepressor response to PGE2. |
