GPCRs and β-arrestins — an on-off relationship

Traditionally,G protein-coupled receptor(GPCR)-mediated G protein signaling has been thought to be terminated by receptor phosphorylation followed by recruitment ofβ-arrestins,which uncouples G protein from the receptor.However,new detailed insights published in Cell by Grimes et al.suggest that the initial agonist-stimulated β-arrestin accumulation at the cell membrane and GPCR-β-arrestin association are mechanistically distinct and much more dynamic than previously appreciated.