Fig. 3.

Fat and Dachsous interactions in the Drosophila wing. (A,B) Schematics of the interactions between Fat (Ft) and Dachsous (Ds) at adherens junctions of epithelial cells in the Drosophila imaginal discs. (A) Ft (cyan) and Ds (magenta) are large atypical cadherin molecules that interact heterophilically. (B) Ft/Ds heterophilic interactions are modulated by Four-jointed (Fj, yellow) activity in the Golgi, which phosphorylates the extracellular cadherin repeats in Ft and Ds as they traffic to the cell surface. Fj-mediated phosphorylation of Ft increases its binding affinity for Ds, whereas phosphorylation of Ds decreases its affinity for Ft.