Fig. 6. W5.34/33 is a common biased signaling switch in dimerizing peptide-binding GPCRs.

a, b Ligand-promoted Gs (V2R) or Go (μOR) and βarr2 recruitment to the membrane in the presence of V2R-WT or V2R-W200^5.33A (a), and μOR-WT or μOR-W230^5.34A (b). Gs and Go activation were detected by monitoring the dissociation between Gα and Gβγ by BRET whereas β-arrestin recruitment to the plasma membrane was assessed in cells transfected with rGFP-CAAX, WT, or mutant receptors, as indicated, and βarr2-RlucII. Data shown represent the mean ± SEM of three independent experiments and are represented as ΔBRET normalized to the maximal response of the WT receptor. The insets represent the maximal agonist-promoted responses for G protein activation (solid bars) and β-arrestin-2 recruitment checkered bars. Statistical significance was assessed using a one-way ANOVA followed by Tukey’s multiple comparison test: ^#p = 0.012, ^##p < 0.0001.