title: Structure of the mouse sex peptide pheromone ESP1 reveals a molecular basis for specific binding to the class C G-protein-coupled vomeronasal receptor.
abstract: Exocrine gland-secreting peptide 1 (ESP1) is a sex pheromone that is released in male mouse tear fluids and enhances female sexual receptive behavior. ESP1 is selectively recognized by a specific class C G-protein-coupled receptor (GPCR), V2Rp5, among the hundreds of receptors expressed in vomeronasal sensory neurons (VSNs). The specific sensing mechanism of the mammalian peptide pheromone by the class C GPCR remains to be elucidated. Here we identified the minimal functional region needed to retain VSN-stimulating activity in ESP1 and determined its three-dimensional structure, which adopts a helical fold stabilized by an intramolecular disulfide bridge with extensive charged patches. We then identified the amino acids involved in the activation of VSNs by a structure-based mutational analysis, revealing that the highly charged surface is crucial for the ESP1 activity. We also demonstrated that ESP1 specifically bound to an extracellular region of V2Rp5 by an in vitro pulldown assay. Based on homology modeling of V2Rp5 using the structure of the metabotropic glutamate receptor, we constructed a docking model of the ESP1-V2Rp5 complex in which the binding interface exhibited good electrostatic complementarity. These experimental results, supported by the molecular docking simulations, reveal that charge-charge interactions determine the specificity of ESP1 binding to V2Rp5 in the large extracellular region characteristic of class C GPCRs. The present study provides insights into the structural basis for the narrowly tuned sensing of mammalian peptide pheromones by class C GPCRs.
authors.affiliation: Faculty of Life Sciences, Kumamoto University, Chuo-ku, Kumamoto 862-0973, Japan.
authors.forename: Sosuke
authors.initials: S
authors.lastname: Yoshinaga
authors.forename: Toru
authors.initials: T
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirakane
authors.forename: Kaori
authors.initials: K
authors.lastname: Esaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamaguchi
authors.forename: Sachiko
authors.initials: S
authors.lastname: Haga-Yamanaka
authors.forename: Mai
authors.initials: M
authors.lastname: Tsunoda
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kimoto
authors.forename: Ichio
authors.initials: I
authors.lastname: Shimada
authors.forename: Kazushige
authors.initials: K
authors.lastname: Touhara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Terasawa
mesh_terms: D000818:Animals; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D062105:Molecular Docking Simulation; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D043563:Receptors, Pheromone / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012724:Sex Attractants / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D043563:Receptors, Pheromone; D012724:Sex Attractants; C525947:exocrine-gland-secreting peptide 1, mouse
keywords: Cell Signaling; Chemoreception; G-protein-coupled Receptor (GPCR); Molecular Recognition; NMR; Neuroscience; Pheromone; Protein Structure; Protein-Protein Interactions; Structural Biology