Y7.53F mutation impaired β-arrestin recruitment. (A) 2-AG-mediated β-arrestin1 recruitment is eliminated in Y7.53F. Data from three biological replicates performed in three technical replicates (N=9) and fit to a three-parameter nonlinear regression curve. Each dose was compared between genotypes by two-way ANOVA followed by Šidák's multiple comparisons test: *p<0.0001. (B) CP55,940 stimulated recruitment of β-arrestin1 in Y7.53F assayed by a β-galactosidase enzyme complementation assay. Data from three biological replicates performed in three technical replicates (N=9) and fit to a three-parameter nonlinear regression curve. Parameters compared by Welch's t test: EC50 (p=0.96) and Emax (72% decrease, p=0.0006). (C) Impaired 2-AG-mediated β-arrestin2 recruitment in Y7.53F. Data from three biological replicates performed in three technical replicates (N=9) and fit to a three-parameter nonlinear regression curve. Parameters compared by Welch's t test: EC50 (p=0.081) and Emax (40% reduction, p=0.024). (D) CP55,940 stimulated recruitment of β-arrestin2 in Y7.53F. Data from three biological replicates performed in three technical replicates (N=9) and fit to a three-parameter nonlinear regression curve. Parameters compared by Welch's t test: EC50 (p=0.72) and Emax (47% reduction, p=0.004). (E) Inhibition of cAMP accumulation by 2-AG in forskolin-treated cells expressing WT or Y7.53F CB1 receptor. Data from four biological replicates performed in three technical replicates (N=12) and fit to a three-parameter nonlinear regression curve. Parameters compared by Welch's t test: IC50 (2.4-fold increase, p=0.013) and Emax (10% increased inhibition of cAMP, p=0.038). (F) Y7.53F reduced 2-AG-mediated stimulation of cAMP accumulation in cells pretreated with PTx. Data from three biological replicates performed in three technical replicates (N=9) and fit to a three-parameter nonlinear regression curve. Parameters compared by Welch's t test: EC50 (5.2-fold increase, p=0.007) and Emax (35% reduction, p=0.015). All data shown as mean±SEM.