Receptor for prostaglandin E2 (PGE2) (PubMed:8396726). The various isoforms have identical ligand binding properties but interact with different second messenger systems: isoform EP3A couples to G(i)/G(o) proteins; isoform EP3B and isoform EP3C couple to G(s), and isoform EP3D couples to G(i), G(s) and G(p) (PubMed:8396726). Required for normal development of fever in response to pyrinogens, including IL1B, prostaglandin E2 and bacterial lipopolysaccharide (LPS). Required for normal potentiation of platelet aggregation by prostaglandin E2, and thus plays a role in the regulation of blood coagulation. Required for increased HCO3(-) secretion in the duodenum in response to mucosal acidification, and thereby contributes to the protection of the mucosa against acid-induced ulceration. Not required for normal kidney function, normal urine volume and osmolality (By similarity). Interacts (via C-terminus) with MKLN1. Additional isoforms seem to exist. Belongs to the G-protein coupled receptor 1 family.