Experimental and computational analysis of biased agonism on full-length and a C-terminally truncated adenosine A receptor
Navarro Brugal, Gemma (Universitat de Barcelona. Departament de Bioquímica i Fisiologia)
Gonzalez, Angel (Universitat Autònoma de Barcelona. Departament de Pediatria, Obstetrícia i Ginecologia i Medicina Preventiva i Salut Pública)
Campanacci, Stefano (Universitat de Barcelona. Departament de Bioquímica i Biomedicina Molecular)
Rivas-Santisteban, Rafael (Universitat de Barcelona. Departament de Bioquímica i Biomedicina Molecular)
Reyes-Resina, Irene (Universitat de Barcelona. Departament de Bioquímica i Biomedicina Molecular)
Casajuana-Martin, Nil (Universitat Autònoma de Barcelona. Departament de Pediatria, Obstetrícia i Ginecologia i Medicina Preventiva i Salut Pública)
Cordomí Montoya, Arnau (Universitat Autònoma de Barcelona. Departament de Pediatria, Obstetrícia i Ginecologia i Medicina Preventiva i Salut Pública)
Pardo Carrasco, Leonardo (Universitat Autònoma de Barcelona. Departament de Pediatria, Obstetrícia i Ginecologia i Medicina Preventiva i Salut Pública)
Franco, Rafael (Universitat de Barcelona. Facultat de Química)

Date:	2020
Abstract:	Biased agonism, the ability of agonists to differentially activate downstream signaling pathways by stabilizing specific receptor conformations, is a key issue for G protein-coupled receptor (GPCR) signaling. The C-terminal domain might influence this functional selectivity of GPCRs as it engages G proteins, GPCR kinases, β-arrestins, and several other proteins. Thus, the aim of this paper is to compare the agonist-dependent selectivity for intracellular pathways in a heterologous system expressing the full-length (AR) and a C-tail truncated (A Δ40 R lacking the last 40 amino acids) adenosine A receptor, a GPCR that is already targeted in Parkinson's disease using a first-in-class drug. Experimental data such as ligand binding, cAMP production, β-arrestin recruitment, ERK1/2 phosphorylation and dynamic mass redistribution assays, which correspond to different aspects of signal transduction, were measured upon the action of structurally diverse compounds (the agonists adenosine, NECA, CGS-21680, PSB-0777 and LUF-5834 and the SCH-58261 antagonist) in cells expressing AR and A Δ40 R. The results show that taking cAMP levels and the endogenous adenosine agonist as references, the main difference in bias was obtained with PSB-0777 and LUF-5834. The C-terminus is dispensable for both G-protein and β-arrestin recruitment and also for MAPK activation. Unrestrained molecular dynamics simulations, at the μs timescale, were used to understand the structural arrangements of the binding cavity, triggered by these chemically different agonists, facilitating G protein binding with different efficacy.
Note:	Funding: This work was partially supported by grants from the Spanish Ministry of Economy and Competitiveness (BFU2015-64405-R, SAF2017-84117-R, RTI2018-094204-B-I00 and PID2019- 109240RB-I00; they may include FEDER funds), the Alzheimer's Association (AARFD-17-503612) and by a grant from Fundacio "la Marato" de TV3 (201413-30).
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	G protein coupled receptors ; Adenosine A receptor ; Functional selectivity ; G protein binding ; β-Arrestin recruitment ; Molecular dynamic simulations
Published in:	Computational and Structural Biotechnology Journal, Vol. 18 (september 2020) , p. 2723-2732, ISSN 2001-0370

DOI: 10.1016/j.csbj.2020.09.028
PMID: 33101610

10 p, 2.0 MB

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