FIGURE 7.

Aβ-induced β₂AR internalization requires ARR3. A, FLAG-β₂AR was expressed in wild type, ARR2-KO, or ARR3-KO MEFs. Cells were stimulated with Aβ (10⁻⁶ m) or isoproterenol (Iso, 10⁻⁷ m) for 40 min, and the distribution of β₂AR was examined with immunofluorescence staining. B, the images of Aβ-induced internalization of β₂AR in panel A were quantified. n = 16. **, p < 0.01 versus control by one-way ANOVA. C, FLAG-β₂AR was expressed together with either wild type ARR3 or V54D dominant negative ARR3 in HEK293 cells. Cells were stimulated with Aβ (10⁻⁶ m) or isoproterenol (10⁻⁷ m) for 40 min, and the distribution of β₂AR was examined with immunofluorescence staining. D, the images of Aβ-induced internalization of β₂AR in panel C were quantified. n = 16. **, p < 0.01 versus control by one-way ANOVA.