Fig. 5. The functional characterization of ligand-specific transducer coupling.

a The functionally selective KOR agonists display preference towards unique transducer coupling. Data are expressed as the mean ± SEM of three independent experiments (n = 3 experiments each done in duplicate). b The mutagenesis screening represented by the heatmap confirms that nalfurafine-specific transducer coupling is affected by specific residues of the receptor. c Positions of residues in nalfurafine-mediated transducer coupling. Values in each plot were summarized in Supplemental Tables 9–11.