title: Distinct phosphorylation sites on the ghrelin receptor, GHSR1a, establish a code that determines the functions of ß-arrestins.
abstract: The growth hormone secretagogue receptor, GHSR1a, mediates the biological activities of ghrelin, which includes the secretion of growth hormone, as well as the stimulation of appetite, food intake and maintenance of energy homeostasis. Mapping phosphorylation sites on GHSR1a and knowledge of how these sites control specific functional consequences unlocks new strategies for the development of therapeutic agents targeting individual functions. Herein, we have identified the phosphorylation of different sets of sites within GHSR1a which engender distinct functionality of ß-arrestins. More specifically, the Ser(362), Ser(363) and Thr(366) residues at the carboxyl-terminal tail were primarily responsible for ß-arrestin 1 and 2 binding, internalization and ß-arrestin-mediated proliferation and adipogenesis. The Thr(350) and Ser(349) are not necessary for ß-arrestin recruitment, but are involved in the stabilization of the GHSR1a-ß-arrestin complex in a manner that determines the ultimate cellular consequences of ß-arrestin signaling. We further demonstrated that the mitogenic and adipogenic effect of ghrelin were mainly dependent on the ß-arrestin bound to the phosphorylated GHSR1a. In contrast, the ghrelin function on GH secretion was entirely mediated by G protein signaling. Our data is consistent with the hypothesis that the phosphorylation pattern on the C terminus of GHSR1a determines the signaling and physiological output.
authors.affiliation: Área de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.|CIBER Fisiopatología de la Obesidad y Nutrición, Spain.
authors.forename: Monica
authors.initials: M
authors.lastname: Bouzo-Lorenzo
authors.affiliation: Área de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.|CIBER Fisiopatología de la Obesidad y Nutrición, Spain.
authors.forename: Icía
authors.initials: I
authors.lastname: Santo-Zas
authors.affiliation: Área de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Lodeiro
authors.affiliation: CIBER Fisiopatología de la Obesidad y Nutrición, Spain.|Departamento de Fisiología, Universidad de Santiago de Compostela (USC), Santiago de Compostela, Spain.
authors.forename: Rubén
authors.initials: R
authors.lastname: Nogueiras
authors.affiliation: Área de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.|CIBER Fisiopatología de la Obesidad y Nutrición, Spain.|Departamento de Medicina, USC, Santiago de Compostela, Spain.
authors.forename: Felipe F
authors.initials: FF
authors.lastname: Casanueva
authors.affiliation: Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), USC, Santiago de Compostela, Spain.
authors.forename: Marian
authors.initials: M
authors.lastname: Castro
authors.affiliation: Área de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.|CIBER Fisiopatología de la Obesidad y Nutrición, Spain.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Pazos
authors.affiliation: Medical Research Council Toxicology Unit, University of Leicester, Hodgkin Building, Lancaster Road, Leicester, LE1 9HN, United Kingdom.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Tobin
authors.affiliation: Medical Research Council Toxicology Unit, University of Leicester, Hodgkin Building, Lancaster Road, Leicester, LE1 9HN, United Kingdom.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Butcher
authors.affiliation: Área de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), Santiago de Compostela, Spain.|CIBER Fisiopatología de la Obesidad y Nutrición, Spain.
authors.forename: Jesús P
authors.initials: JP
authors.lastname: Camiña
mesh_terms: D057809:HEK293 Cells; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D000072417:Protein Domains; D054440:Receptors, Ghrelin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D000071557:beta-Arrestins / Q000235:genetics / Q000378:metabolism*
chemical_list: D046912:Multiprotein Complexes; D054440:Receptors, Ghrelin; D000071557:beta-Arrestins