Frizzled-Induced Van Gogh Phosphorylation by CK1ε Promotes Asymmetric Localization of Core PCP Factors in Drosophila.

Epithelial tissues are polarized along two axes. In addition to apical-basal polarity, they are often polarized within the plane of the epithelium, so-called Planar Cell Polarity (PCP). PCP depends upon Wnt/Frizzled (Fz) signaling factors, including Fz itself and Van Gogh (Vang/Vangl).

Functional dissection of phosphorylation of Disheveled in Drosophila.

Disheveled/Dsh proteins (Dvl in mammals) are core components of both Wnt/Wg-signaling pathways: canonical β-catenin signaling and Frizzled (Fz)-planar cell polarity (PCP) signaling. Although Dsh is a key cytoplasmic component of both Wnt/Fz-pathways, regulation of its signaling specificity is not well understood. Dsh is phosphorylated, but the functional significance of its phosphorylation remains unclear.

Abelson family kinases regulate Frizzled planar cell polarity signaling via Dsh phosphorylation.

Abelson (Abl) family tyrosine kinases have been implicated in cell morphogenesis, adhesion, motility, and oncogenesis. Using a candidate approach for genes involved in planar cell polarity (PCP) signaling, we identified Drosophila Abl (dAbl) as a modulator of Frizzled(Fz)/PCP signaling. We demonstrate that dAbl positively regulates the Fz/Dishevelled (Dsh) PCP pathway without affecting canonical Wnt/Wg-Fz signaling.

Phosphorylation of frizzled-3.

Wnts are secreted proteins important to many biological processes. frizzled genes encode a family of Wnt receptors that signal to the intracellular compartment through the cytosolic protein Disheveled. Limited information is available concerning the regulation of Frizzleds at a biochemical level.