The PCP signaling pathway in Drosophila. The PCP pathway is activated when a Wnt ligand binds to a Frizzled (Fz) receptor and induces a clustering of the core PCP proteins to either proximal (Van Gogh-like (Vangl) and Prickle (Pk)) or distal (Dishevelled (Dvl) and Fz, Diego) cellular domains. Activation of PCP signaling is associated with Dvl phosphorylation. Flamingo (Celsr) is found at both sides. Apical-basal regulator Scribble also regulates PCP in the fruitflies and genetically interacts with Vangl2. Dachsous (Ds) and Fat (Ft) protocadherins form heterotypic complexes at both sides of the cell and provide global positioning cues; phosphorylation of Ft and Ds by the Four-jointed (Fj) kinase regulates the strength of the Ds-Ft complex. Asymmetric distribution of the core PCP proteins induces asymmetric clustering and activation of downstream PCP effectors Inturned (In), Fuzzy (Fuz), Fritz, and multiple wing hair (Mwh) as well as a Rho GTPase, Jun kinase, and others. This leads to actin rearrangement necessary for polarized asymmetric distribution of cellular appendages.