title: Functional characterization of a short neuropeptide F-related receptor in a lophotrochozoan, the mollusk Crassostrea gigas.
abstract: Members of the short neuropeptide F (sNPF) family of peptides and their cognate receptors play key roles in a variety of physiological processes in arthropods. In silico screening of GigasDatabase, a specific expressed sequence tag database from the Pacific oyster Crassostrea gigas, resulted in the identification of a receptor (Cg-sNPFR-like) phylogenetically closely related to sNPF receptors (sNPFRs) of insects. A reverse endocrinology approach was undertaken to identify the peptide ligand(s) of this orphan receptor. Though structurally distinct from insect sNPFs, three RFamide peptides derived from the same precursor, i.e. GSLFRFamide, SSLFRFamide and GALFRFamide, specifically activate the receptor in a dose-dependent manner, with respective EC50 values (half-maximal effective concentrations) of 1.1, 2.1 and 4.1 μmol l(-1). We found that both Cg-sNPFR-like receptor and LFRFamide encoding transcripts are expressed in the oyster central nervous system and in other tissues as well, albeit at lower levels. Mass spectrometry analysis confirmed the wide distribution of LFRFamide mature peptides in several central and peripheral tissues. The Cg-sNPFR-like receptor was more abundantly expressed in ganglia of females than of males, and upregulated in starved oysters. In the gonad area, highest receptor gene expression occurred at the start of gametogenesis, when storage activity is maximal. Our results suggest that signaling of LFRFamide peptides through the Cg-sNPFR-like receptor might play a role in the coordination of nutrition, energy storage and metabolism in C. gigas, possibly by promoting storage at the expense of reproduction.
authors.affiliation: Université de Caen Basse-Normandie, Biologie des Organismes Aquatiques et Ecosystèmes (BOREA), CS 14032, 14032 Caen Cedex 05, France CNRS UMR 7208, BOREA, CS 14032, 14032 Caen Cedex 05, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Bigot
authors.affiliation: Department of Biology, Functional Genomics and Proteomics Group, KU Leuven, 3000 Leuven, Belgium.
authors.forename: Isabel
authors.initials: I
authors.lastname: Beets
authors.affiliation: Université de Caen Basse-Normandie, Biologie des Organismes Aquatiques et Ecosystèmes (BOREA), CS 14032, 14032 Caen Cedex 05, France CNRS UMR 7208, BOREA, CS 14032, 14032 Caen Cedex 05, France.
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Dubos
authors.affiliation: Ifremer, Unité Physiologie Fonctionnelle des Organismes Marins, UMR 6539 LEMAR, 29280 Plouzané, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Boudry
authors.affiliation: Department of Biology, Functional Genomics and Proteomics Group, KU Leuven, 3000 Leuven, Belgium.
authors.forename: Liliane
authors.initials: L
authors.lastname: Schoofs
authors.affiliation: Université de Caen Basse-Normandie, Biologie des Organismes Aquatiques et Ecosystèmes (BOREA), CS 14032, 14032 Caen Cedex 05, France CNRS UMR 7208, BOREA, CS 14032, 14032 Caen Cedex 05, France pascal.favrel@unicaen.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Favrel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D049896:Crassostrea / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D018013:Receptors, Neuropeptide / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D018013:Receptors, Neuropeptide
keywords: Crassostrea gigas; Energy metabolism; Oyster; Reproduction; Starvation; sNPF