Figure 2.

Agonist-promoted internalization of M₂ mAChR in MEFs is β-arrestin-dependent. A.) Approximately 24 h following transfection with M₂ mAChR, cells were stimulated with 1 mM carbachol for 1 h and agonist-promoted internalization was determined using [³H-NMS]. Data are presented as the mean ± standard error from 3 separate experiments with each experiment consisting of 8 to 11 independent determinations. Statistical test was performed using ANOVA with the post hoc Bonferroni/Dunn test (asterisk indicates * p < 0.001). B.) Cells were transfected as described above and then incubated in the presence or absence of 1 mM carbachol for 30 minutes prior to indirect immunofluorescence as described in Methods. Images were acquired at 40X.