RESUMO
Endosomes, long considered as sorting stations for downregulation and recycling of cell surface G protein-coupled receptors (GPCRs), are now well-established sites of signal transduction. Recent work from the groups of Jin Zhang and Roger Sunahara features endosomes as signaling hubs and physical platforms for noncanonical activation of ERK by GPCRs.
Assuntos
Endossomos , Sistema de Sinalização das MAP Quinases , Receptores Acoplados a Proteínas G , Humanos , Membrana Celular/metabolismo , Endossomos/metabolismo , Transporte Proteico/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Carvedilol is among the most effective ß-blockers for improving survival after myocardial infarction. Yet the mechanisms by which carvedilol achieves this superior clinical profile are still unclear. Beyond blockade of ß1-adrenoceptors, arrestin-biased signalling via ß2-adrenoceptors is a molecular mechanism proposed to explain the survival benefits. Here, we offer an alternative mechanism to rationalize carvedilol's cellular signalling. Using primary and immortalized cells genome-edited by CRISPR/Cas9 to lack either G proteins or arrestins; and combining biological, biochemical, and signalling assays with molecular dynamics simulations, we demonstrate that G proteins drive all detectable carvedilol signalling through ß2ARs. Because a clear understanding of how drugs act is imperative to data interpretation in basic and clinical research, to the stratification of clinical trials or to the monitoring of drug effects on the target pathway, the mechanistic insight gained here provides a foundation for the rational development of signalling prototypes that target the ß-adrenoceptor system.