title: Unconventional binding sites and receptors for VIP and related peptides PACAP and PHI/PHM: an update.
abstract: The 28-amino-acid neuropeptide VIP and related peptides PACAP and PHI/PHM modulate virtually all of the vital functions in the body. These peptides are also commonly recognized as major regulators of cell growth and differentiation. Through their trophic and cytoprotective functions, they appear to play major roles in embryonic development, neurogenesis and the progression of a number of cancer types. These peptides bind to three well-characterized subtypes of G-protein coupled receptors: VPAC1 and VPAC2 share a common high affinity in the nanomolar range for VIP and PACAP; a third receptor type, PAC1, has been characterized for its high affinity for PACAP but its low affinity for VIP. Complex effects and pharmacological behaviors of these peptides suggest that multiple subtypes of binding sites may cooperate to mediate their function in target cells and tissues. In this complex response, some of these binding sites correspond to the definition of the conventional receptors cited above, while others display unexpected pharmacological and functional properties. Here we present potential clues that may lead investigators to further characterize the molecular nature and functions of these atypical binding species.
authors.affiliation: Institut de Physiologie et Biologie Cellulaires, UMR CNRS 6187, Université de Poitiers, Pôle Biologie-Santé, 40 Avenue du Recteur Pineau, 86022 Poitiers Cedex, France. jean.marc.muller@univ-poitiers.fr
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Muller
authors.forename: Colin
authors.initials: C
authors.lastname: Debaigt
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Goursaud
authors.forename: Alicia
authors.initials: A
authors.lastname: Montoni
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pineau
authors.forename: Annie-Claire
authors.initials: AC
authors.lastname: Meunier
authors.forename: Thierry
authors.initials: T
authors.lastname: Janet
mesh_terms: D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D006801:Humans; D010451:Peptide PHI / Q000378:metabolism; D018000:Receptors, Peptide / Q000378:metabolism*; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide / Q000378:metabolism*; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I / Q000378:metabolism*
chemical_list: C042452:PHI peptide receptor; D010451:Peptide PHI; D018000:Receptors, Peptide; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I