Receptor for prostaglandin E2 (PGE2). The activity of this receptor is mediated by G(q) proteins which activate a phosphatidylinositol-calcium second messenger system. May play a role as an important modulator of renal function. Implicated the smooth muscle contractile response to PGE2 in various tissues. This is the function of Ensembl gene identifier ENSG00000160951 (PTGER1, prostaglandin E receptor 1).