title: Dopamine D(2) receptor-mediated modulation of adenosine A(2A) receptor agonist binding within the A(2A)R/D(2)R oligomer framework.
abstract: The molecular interaction between adenosine A2A and dopamine D2 receptors (A2ARs and D2Rs, respectively) within an oligomeric complex has been postulated to play a pivotal role in the adenosine-dopamine interplay in the central nervous system, in both normal and pathological conditions (e.g. Parkinson's disease). While the effects of A2AR challenge on D2R functioning have been largely studied, the reverse condition is still unexplored, a fact that might have impact in therapeutics. Here, we aimed to examine in a real-time mode the D2R-mediated allosteric modulation of A2AR binding when an A2AR/D2R oligomer is established. Thus, we synthesized fluorescent A2AR agonists and evaluated, by means of a flow cytometry homogeneous no-wash assay and a real-time fluorescence resonance energy transfer (FRET)-based approach, the effects on A2AR binding of distinct antiparkinsonian drugs in current clinical use (i.e. pramipexole, rotigotine and apomorphine). Our results provided evidence for the existence of a differential D2R-mediated negative allosteric modulation on A2AR agonist binding that was oligomer-formation dependent, and with apomorphine being the best antiparkinsonian drug attenuating A2AR agonist binding. Overall, the here-developed methods were found valid to explore the ability of drugs acting on D2Rs to modulate A2AR binding, thus serving to facilitate the preliminary selection of D2R-like candidate drugs in the management of Parkinson's disease.
authors.affiliation: Unitat de Farmacologia, Departament de Patologia i Terapèutica Experimental, Facultat de Medicina, IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Fernández-Dueñas
authors.forename: Maricel
authors.initials: M
authors.lastname: Gómez-Soler
authors.forename: Xavier
authors.initials: X
authors.lastname: Morató
authors.forename: Fabiana
authors.initials: F
authors.lastname: Núñez
authors.forename: Arijit
authors.initials: A
authors.lastname: Das
authors.forename: T Santhosh
authors.initials: TS
authors.lastname: Kumar
authors.forename: Serge
authors.initials: S
authors.lastname: Jaumà
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Jacobson
authors.forename: Francisco
authors.initials: F
authors.lastname: Ciruela
mesh_terms: D058908:Adenosine A2 Receptor Agonists / Q000378:metabolism*; D001704:Biopolymers / Q000378:metabolism*; D005434:Flow Cytometry; D031541:Fluorescence Resonance Energy Transfer; D057809:HEK293 Cells; D006801:Humans; D011485:Protein Binding; D043705:Receptor, Adenosine A2A / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism / Q000502:physiology*
chemical_list: D058908:Adenosine A2 Receptor Agonists; D001704:Biopolymers; D043705:Receptor, Adenosine A2A; D017448:Receptors, Dopamine D2