Fig. 3.
β-Arrestin2 is a necessary component of canonical Wnt signaling in MEFs. (A) WT, β-arr2KO, or β-arr1/2dKO MEFs are treated with 100 ng/ml Wnt-3a for the indicated times. Dvl2 activation is assessed as the formation of PS-Dvl2 (Dvl, open; PS-Dvl, filled arrowheads) by immunoblotting. (B) Wnt-3a dose responses were performed at 2 h. (C) Quantification of data is available in SI Fig. 7. Phosphorylation of LRP6 at Ser-1490 (P-LRP6) and β-catenin signaling was analyzed in WT, β-arr2KO, and β-arr1/2dKO MEFs after 100 ng/ml Wnt-3a treatment for 2 h. Dephosphorylation of β-catenin (ABC) and β-catenin stabilization show that Wnt-3a-induced signaling to β-catenin is reduced in β-arr2KO MEFs and completely abolished in β-arr1/2dKO MEFs. For responses in β-arr1KO MEFs, see SI Fig. 8. (D) SuperTOPflash activity upon 100 ng/ml Wnt-3a stimulation is shown (n = 3). ∗, P < 0.01 as analyzed by ANOVA and Tukey′s post hoc tests.