title: Recruitment of beta-arrestin2 to the dopamine D2 receptor: insights into anti-psychotic and anti-parkinsonian drug receptor signaling.
abstract: Drugs acting at dopamine D2-like receptors play a pivotal role in the treatment of both schizophrenia and Parkinson's disease. Recent studies have demonstrated a role for G-protein independent D2 receptor signaling pathways acting through beta-arrestin. In this study we describe the establishment of a Bioluminescence Resonance Energy Transfer (BRET) assay for measuring dopamine induced recruitment of human beta-arrestin2 to the human dopamine D2 receptor. Dopamine, as well as the dopamine receptor agonists pramipexole and quinpirole, acted as full agonists in the assay as reflected by their ability to elicit marked concentration dependent increases in the BRET signal signifying beta-arrestin2 recruitment to the D2 receptor. As expected from their effect on G-protein coupling and cAMP levels mediated through the D2 receptor RNPA, pergolide, apomorphine, ropinirole, bromocriptine, 3PPP, terguride, aripiprazole, SNPA all acted as partial agonists with decreasing efficacy in the BRET assay. In contrast, a wide selection of typical and atypical anti-psychotics was incapable of stimulating beta-arrestin2 recruitment to the D2 receptor. Moreover, we observed that haloperidol, sertindole, olanzapine, clozapine and ziprasidone all fully inhibited the dopamine induced beta-arrestin2 recruitment to D2 receptor (short variant) in a concentration dependent manner. We conclude that most anti-psychotics are incapable of stimulating beta-arrestin2 recruitment to the dopamine D2 receptor, in accordance with their antagonistic properties at the level of G-protein coupling.
authors.affiliation: H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark. ibkl@sund.ku.dk
authors.forename: Ib V
authors.initials: IV
authors.lastname: Klewe
authors.forename: Søren M
authors.initials: SM
authors.lastname: Nielsen
authors.forename: Louise
authors.initials: L
authors.lastname: Tarpø
authors.forename: Eneko
authors.initials: E
authors.lastname: Urizar
authors.forename: Concetta
authors.initials: C
authors.lastname: Dipace
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Javitch
authors.forename: Ulrik
authors.initials: U
authors.lastname: Gether
authors.forename: Jan
authors.initials: J
authors.lastname: Egebjerg
authors.forename: Kenneth V
authors.initials: KV
authors.lastname: Christensen
mesh_terms: D000595:Amino Acid Sequence; D000978:Antiparkinson Agents / Q000494:pharmacology*; D014150:Antipsychotic Agents / Q000494:pharmacology*; D019390:Arrestins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D003627:Data Interpretation, Statistical; D031541:Fluorescence Resonance Energy Transfer; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006801:Humans; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D014677:Pharmaceutical Vehicles; D010957:Plasmids / Q000235:genetics; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D000071557:beta-Arrestins
chemical_list: D000978:Antiparkinson Agents; D014150:Antipsychotic Agents; D019390:Arrestins; D014677:Pharmaceutical Vehicles; D017448:Receptors, Dopamine D2; D000071557:beta-Arrestins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D004247:DNA; D000242:Cyclic AMP