Fig. 2

Signaling of the β₂AR. a Simplified schematic of β₂AR signaling pathways monitored in this study. b Concentration response curves of the five monitored pathways for WT and three variants of β₂AR to exemplify original data. K273A is representative of mutations that yielded a signaling profile similar to WT whereas I127N exemplifies mutations increasing the constitutive activity of Gi that abrogate its ISO stimulation and reducing most of βarrestin engagement and endocytosis whereas R328A exemplifies mutations in which Gi constitutive activity is increased and ISO stimulation is abrogated but βarrestin and endocytosis are maintained. For each concentration response curve, the β₂AR-unspecific response (value of cells only transfected with the biosensor (no receptor added)) was set to 0% and the maximal ISO-stimulated response of WT β₂AR to 100%. The non-stimulated condition (veh) represents the basal activity in each monitored pathway. Data for all β₂AR variants is given in Supplementary Fig. 2. For details, see Methods