title: Functional Overexpression of Vomeronasal Receptors Using a Herpes Simplex Virus Type 1 (HSV-1)-Derived Amplicon.
abstract: In mice, social behaviors such as mating and aggression are mediated by pheromones and related chemosignals. The vomeronasal organ (VNO) detects olfactory information from other individuals by sensory neurons tuned to respond to specific chemical cues. Receptors expressed by vomeronasal neurons are implicated in selective detection of these cues. Nearly 400 receptor genes have been identified in the mouse VNO, but the tuning properties of individual receptors remain poorly understood, in part due to the lack of a robust heterologous expression system. Here we develop a herpes virus-based amplicon delivery system to overexpress three types of vomeronasal receptor genes and to characterize cell responses to their proposed ligands. Through Ca2+ imaging in native VNO cells we show that virus-induced overexpression of V1rj2, V2r1b or Fpr3 caused a pronounced increase of responsivity to sulfated steroids, MHC-binding peptide or the synthetic hexapeptide W-peptide, respectively. Other related ligands were not recognized by infected individual neurons, indicating a high degree of selectivity by the overexpressed receptor. Removal of G-protein signaling eliminates Ca2+ responses, indicating that the endogenous second messenger system is essential for observing receptor activation. Our results provide a novel expression system for vomeronasal receptors that should be useful for understanding the molecular logic of VNO ligand detection. Functional expression of vomeronasal receptors and their deorphanization provides an essential requirement for deciphering the neural mechanisms controlling behavior.
authors.affiliation: Department of Physiology, and Center for Integrative Physiology and Molecular Medicine, University of Saarland School of Medicine, Homburg, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Stein
authors.affiliation: Instituto de Biología y Genética Molecular (IBGM), University of Valladolid and CSIC, Valladolid, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Alonso
authors.affiliation: Department of Physiology, and Center for Integrative Physiology and Molecular Medicine, University of Saarland School of Medicine, Homburg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Zufall
authors.affiliation: Department of Physiology, and Center for Integrative Physiology and Molecular Medicine, University of Saarland School of Medicine, Homburg, Germany.
authors.forename: Trese
authors.initials: T
authors.lastname: Leinders-Zufall
authors.affiliation: Department of Physiology, and Center for Integrative Physiology and Molecular Medicine, University of Saarland School of Medicine, Homburg, Germany.|Laboratoire de Physiologie de la Reproduction & des Comportements, UMR85 INRA-CNRS-IFCE-Université de Tours, Nouzilly, France.
authors.forename: Pablo
authors.initials: P
authors.lastname: Chamero
mesh_terms: D000818:Animals; D020013:Calcium Signaling; D002478:Cells, Cultured; D002628:Chemoreceptor Cells / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D057809:HEK293 Cells; D018259:Herpesvirus 1, Human / Q000235:genetics; D006801:Humans; D008024:Ligands; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009479:Neuropeptides / Q000378:metabolism; D018035:Receptors, Odorant / Q000235:genetics / Q000378:metabolism*; D013256:Steroids / Q000378:metabolism; D019147:Vomeronasal Organ / Q000166:cytology / Q000378:metabolism*
chemical_list: D008024:Ligands; D009479:Neuropeptides; D018035:Receptors, Odorant; D013256:Steroids; D019204:GTP-Binding Proteins