Cross-communication between Gi and Gs in a G-protein-coupled receptor heterotetramer guided by a receptor C-terminal domain

BACKGROUND: G-protein-coupled receptor (GPCR) heteromeric complexes have distinct properties from homomeric GPCRs, giving rise to new receptor functionalities. Adenosine receptors (A1R or A2AR) can form A1R-A2AR heteromers (A1-A2AHet), and their activation leads to canonical G-protein-dependent (ade...

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Detalles Bibliográficos
Autores: Navarro Brugal, Gemma, Cordomí, Arnau, Brugarolas Campillos, Marc, Moreno Guillén, Estefanía, Aguinaga Andrés, David, Pérez-Benito, Laura, Ferré, Sergi, Cortés Tejedor, Antonio, Casadó, Vicent, Mallol Montero, Josefa, Canela Campos, Enric I. (Enric Isidre), 1949-, Lluís i Biset, Carme, Pardo, Leonardo, McCormick, Peter J., Franco Fernández, Rafael
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/120611
Acceso en línea:https://hdl.handle.net/2445/120611
Access Level:acceso abierto
Palabra clave:Adenosina
Receptors cel·lulars
Adenosine
Cell receptors
Descripción
Sumario:BACKGROUND: G-protein-coupled receptor (GPCR) heteromeric complexes have distinct properties from homomeric GPCRs, giving rise to new receptor functionalities. Adenosine receptors (A1R or A2AR) can form A1R-A2AR heteromers (A1-A2AHet), and their activation leads to canonical G-protein-dependent (adenylate cyclase mediated) and -independent (β-arrestin mediated) signaling. Adenosine has different affinities for A1R and A2AR, allowing the heteromeric receptor to detect its concentration by integrating the downstream Gi- and Gs-dependent signals. cAMP accumulation and β-arrestin recruitment assays have shown that, within the complex, activation of A2AR impedes signaling via A1R. RESULTS: We examined the mechanism by which A1-A2AHet integrates Gi- and Gs-dependent signals. A1R blockade by A2AR in the A1-A2AHet is not observed in the absence of A2AR activation by agonists, in the absence of the C-terminal domain of A2AR, or in the presence of synthetic peptides that disrupt the heteromer interface of A1-A2AHet, indicating that signaling mediated by A1R and A2AR is controlled by both Gi and Gs proteins. CONCLUSIONS: We identified a new mechanism of signal transduction that implies a cross-communication between Gi and Gs proteins guided by the C-terminal tail of the A2AR. This mechanism provides the molecular basis for the operation of the A1-A2AHet as an adenosine concentration-sensing device that modulates the signals originating at both A1R and A2AR.