Fig. 5: Functional studies of the signaling from β1-ARs initiated by a full agonist, a partial agonist, or a very weak partial agonist.
From: Structures of β1-adrenergic receptor in complex with Gs and ligands of different efficacies
a, b Effects of receptor mutations on isoproterenol-induced cAMP responses. a Dose–response data from cells expressing different β1-AR constructs after stimulation with isoproterenol. b Summary of the efficacy (the maximum cAMP level of a mutant receptor/the maximum cAMP level of the wild-type receptor) and EC50 values based on the cAMP assay data shown in (a). a and b are adapted from20 and used here for direct comparison. c, d Effects of mutations on dobutamine-induced cAMP responses. c Dose–response data from cells expressing different β1-ARs after stimulation with dobutamine. d Summary of the efficacy and EC50 values based on the cAMP assay data shown in (c). e, f Effects of mutations on cyanopindolol-induced cAMP responses. e Dose–response data from cells expressing different β1-ARs after stimulation with cyanopindolol. f Summary of the efficacy and EC50 values based on the cAMP assay data shown in (e). Data are shown as mean ± SD of three experiments. The analysis was done using the log(agonist) vs. response function of Prism 8 (GraphPad). When comparing with the wild-type receptor, all mutant receptors showed significant difference with p values < 0.05 (Student’s t-test, two-sided). The color keys for the receptor mutants are the same for (c) and (e), and are displayed in (e). Source data are provided as a Source Data file.
