Arrb2 physically interacts with Gβ and Dvl.

<p>Epitope-tagged proteins were overexpressed, immunoprecipitated and detected by Western Blotting as indicated. (A) Flag-Arrb2 was co-expressed with a combination of HA-Gβ1 and HA-Gγ2 to allow the formation of Gβγ heterodimers (Gβγ). Co-expression of Dvl1, Dvl2 or Dvl3 enhanced the interaction between Arrb2 and Gβ1 in co-immunoprecipitation experiments from HEK 293T cells. (B) Endogenous Gβ and Dvl2 were detected in immunoprecipitates of endogenous Arrb2 from unstimulated and Wnt-stimulated HEK 293T cells. (C) Binding of Dvl2 to Arrb2 was also observed in the absence of exogenous Gβ. Myc-Dvl2 co-precipitated equally well with Flag-Arrb2 when Gβ1 and Gγ2 were overexpressed (Gβγ) as in the presence of the Gβ-sequestering β-ARKct in HEK 293T cells. By contrast, binding of Gβ1 to Arrb2 was impaired by β-ARKct and partially restored by co-expression of Dvl2. (D) When myc-Dvl2 was precipitated, the amount of Flag-Arrb2 and that of Gβ1 that co-precipitated with Dvl2 was significantly reduced by the co-expression of β-ARKct.