title: The prostanoid EP4 receptor and its signaling pathway.
abstract: The EP4 prostanoid receptor is one of four receptor subtypes for prostaglandin E2. It belongs to the family of G protein-coupled receptors. It was originally identified, similar to the EP2 receptor as a G(s)α-coupled, adenylyl cyclase-stimulating receptor. EP4 signaling plays a variety of roles through cAMP effectors, i.e., protein kinase A and exchange protein activated by cAMP. However, emerging evidence from studies using pharmacological approaches and genetically modified mice suggests that EP4, unlike EP2, can also be coupled to G(i)α, phosphatidylinositol 3-kinase, β-arrestin, or β-catenin. These signaling pathways constitute unique roles for the EP4 receptor. EP4 is widely distributed in the body and thus plays various physiologic and pathophysiologic roles. In particular, EP4 signaling is closely related to carcinogenesis, cardiac hypertrophy, vasodilation, vascular remodeling, bone remodeling, gastrointestinal homeostasis, renal function, and female reproductive function. In addition to the classic anti-inflammatory action of EP4 on mononuclear cells and T cells, recent evidence has shown that EP4 signaling contributes to proinflammatory action as well. The aim of this review is to present current findings on the biologic functions of the EP4 receptor. In particular, we will discuss its diversity from the standpoint of EP4-mediated signaling.
authors.affiliation: Cardiovascular Research Institute, Yokohama City University, Yokohama, Kanagawa, Japan.
authors.forename: Utako
authors.initials: U
authors.lastname: Yokoyama
authors.forename: Kousaku
authors.initials: K
authors.lastname: Iwatsubo
authors.forename: Masanari
authors.initials: M
authors.lastname: Umemura
authors.forename: Takayuki
authors.initials: T
authors.lastname: Fujita
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ishikawa
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002319:Cardiovascular System / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000378:metabolism; D006801:Humans; D007107:Immune System / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism; D009420:Nervous System / Q000378:metabolism; D058309:Receptors, Prostaglandin E, EP4 Subtype / Q000378:metabolism*; D015398:Signal Transduction; D012867:Skin / Q000378:metabolism
chemical_list: D058309:Receptors, Prostaglandin E, EP4 Subtype