Fig. 2.
Conformational changes in β-arrestin 2 upon stimulation of β2AR measured by intramolecular BRET. HEK-293 cells overexpressing β2AR or β2ARTYY mutant were transiently transfected with β-arrestin 2 double brilliance biosensor (Luc–β-arr–YFP). (A) Cells were stimulated with isoproterenol (1 μM, 10 min), and translocation of β-arrestin 2 biosensor was visualized by confocal microscopy. Images are representative of four independent experiments. (B and C) Changes in intramolecular BRET ratio upon stimulation of wild-type β2AR (B) and β2ARTYY mutant (C) by isoproterenol (1 μM, 10 min) with or without pretreatment with β2AR antagonist propranolol (10 μM, 10 min). Data are mean ± SD of seven independent experiments, each performed at least in triplicates. *, P < 0.05; **, P < 0.01—between basal and stimulated condition as analyzed by one-way ANOVA with Bonferroni's post-test.