Dishevelled 2 Recruits ß-Arrestin 2 to Mediate Wnt5A-Stimulated Endocytosis of Frizzled 4

Abstract

Wnt proteins, regulators of development in many organisms, bind to seven transmembrane–spanning (7TMS) receptors called frizzleds, thereby recruiting the cytoplasmic molecule dishevelled (Dvl) to the plasma membrane.Frizzled-mediated endocytosis of Wg (a Drosophila Wnt protein) and lysosomal degradation may regulate the formation of morphogen gradients. Endocytosis of Frizzled 4 (Fz4) in human embryonic kidney 293 cells was dependent on added Wnt5A protein and was accomplished by the multifunctional adaptor protein β-arrestin 2 (βarr2), which was recruited to Fz4 by binding to phosphorylated Dvl2. These findings provide a previously unrecognized mechanism for receptor recruitment of β-arrestin and demonstrate that Dvl plays an important role in the endocytosis of frizzled, as well as in promoting signaling.