Development of a human vasopressin V1a-receptor antagonist from an evolutionary-related insect neuropeptide Journal Article

Author(s): Di Giglio, Maria G; Muttenthaler, Markus; Harpsøe, Kasper; Liutkeviciute, Zita; Keov, Peter; Eder, Thomas; Rattei, Thomas; Arrowsmith, Sarah; Wray, Susan; Marek, Ales; Elbert, Tomas; Alewood, Paul F; Gloriam, David E; Gruber, Christian W
Article Title: Development of a human vasopressin V1a-receptor antagonist from an evolutionary-related insect neuropeptide
Affiliation IST Austria
Abstract: Characterisation of G protein-coupled receptors (GPCR) relies on the availability of a toolbox of ligands that selectively modulate different functional states of the receptors. To uncover such molecules, we explored a unique strategy for ligand discovery that takes advantage of the evolutionary conservation of the 600-million-year-old oxytocin/vasopressin signalling system. We isolated the insect oxytocin/vasopressin orthologue inotocin from the black garden ant (Lasius niger), identified and cloned its cognate receptor and determined its pharmacological properties on the insect and human oxytocin/vasopressin receptors. Subsequently, we identified a functional dichotomy: inotocin activated the insect inotocin and the human vasopressin V1b receptors, but inhibited the human V1aR. Replacement of Arg8 of inotocin by D-Arg8 led to a potent, stable and competitive V1aR-antagonist ([D-Arg8]-inotocin) with a 3,000-fold binding selectivity for the human V1aR over the other three subtypes, OTR, V1bR and V2R. The Arg8/D-Arg8 ligand-pair was further investigated to gain novel insights into the oxytocin/vasopressin peptide-receptor interaction, which led to the identification of key residues of the receptors that are important for ligand functionality and selectivity. These observations could play an important role for development of oxytocin/vasopressin receptor modulators that would enable clear distinction of the physiological and pathological responses of the individual receptor subtypes.
Keywords: pharmacology; Entomology; PeptidesReceptor
Journal Title: Scientific Reports
Volume: 7
ISSN: 20452322
Publisher: Nature Publishing Group  
Date Published: 2017-02-01
Start Page: Article number: 41002
Copyright Statement: CC BY 4.0
DOI: 10.1038/srep41002
Notes: We thank Yoonseong Park (Kansas State University) for supplying a plasmid encoding the inotocin receptor from Tribolium castaneum, Amir Seddik (The University of Queensland) for help with synthetic work and Markus Gold-Binder (Medical University of Vienna) for technical support. We thank Anna V. Grasse and Sylvia Cremer for providing the RNA of Lasius niger ants and for comments on the manuscript. This research has been funded by the Vienna Science and Technology Fund (WWTF) through project LS13-017 (awarded to Christian W. Gruber, Sylvia Cremer and Markus Muttenthaler). Christian W. Gruber has been supported by an Australian Research Council Future Fellowship (FT140100730) and the Austrian Science Fund FWF (P24743). Markus Muttenthaler received funding from the Australian Research Council (DE150100784). Paul Alewood was supported by the Australian National Health & Medical Research Council. Synthesis of [3H] inotocin was supported by the Academy of Sciences of the Czech Republic, through program RVO: 61388963.
Open access: yes (OA journal)