Fig. 6: Arrestin-3 recruitment to inactive β₂-adrenergic receptor (β₂AR).

HEK293 arrestin2/3 KO cells were co-transfected with plasmids encoding arrestin-3 (A–D) or arrestin-2 (E–H), both with N-terminal SmBiT and β₂AR (A, C, E, and G) or M₂R (B, D, F, and H) with C-terminal LgBiT. The cells were treated with 100 mM L^SH3 or DMSO (vehicle control) for 30 min prior to the addition of luciferase substrate (time point 0). Agonist (10 mM isoproterenol (ISO) for β₂AR or 10 mM carbachol for M₂R) was added at 30 min. A Arrestin-3 recruitment to β₂AR. B Arrestin-3 recruitment to M₂R. C Arrestin-3 recruitment to inactive β₂AR (no agonist). D Arrestin-3 recruitment to inactive M₂R. E Arrestin-2 recruitment to β₂AR. F Arrestin-2 recruitment to M₂R. G Arrestin-2 recruitment to inactive β₂AR. H Arrestin-2 recruitment to inactive M₂R. Data are presented as means ± SEM (N = 6). Statistical significance was determined by two-way repeat measures ANOVA followed by Fisher’s LSD post hoc test and indicated, as follows: *, p < 0.05.