PTGER1, Prostaglandin E Receptor 1, comprises 402 amino acids with a predicted molecular mass of 41,858 and has the 7 predicted transmembrane-spanning domains common to all G protein-coupled receptors. The PTGER1 gene is mapped to chromosome 19p13.1. The protein encoded by this gene is a member of the G protein-coupled receptor family. This protein is one of four receptors identified for prostaglandin E2 (PGE2). Through a phosphatidylinositol-calcium second messenger system, Gq proteins mediate this receptor's activity. Knockout studies in mice suggested a role of this receptor in mediating algesia and in regulation of blood pressure. Studies in mice also suggested that this gene may mediate adrenocorticotropic hormone response to bacterial endotoxin.