Lgl cortical dynamics are independent of binding to the Scrib-Dlg complex but require Dlg-dependent restriction of aPKC

摘要: Apical-basal polarity underpins the formation of specialized epithelial barriers that are critical for metazoan physiology. Although apical-basal is long known to require basolateral determinants Lethal Giant Larvae (Lgl), Discs Large (Dlg) and Scribble (Scrib), mechanistic understanding their function limited. Lgl plays a role as an aPKC inhibitor, but it remains unclear whether also forms complex with Dlg or Scrib. Using fluorescence recovery after photobleaching, we show does not form immobile complexes at lateral domain Drosophila follicle cells. Optogenetic depletion plasma membrane phosphatidylinositol 4,5-biphosphate (PIP2) removal accelerate cortical dynamics. However, whereas turnover relies on PIP2 binding, Scrib only required localization dynamic behavior in presence function. Furthermore, light-induced oligomerization proteins indicate part Scrib-Dlg vivo. Thus, necessary repress activity do provide binding sites Lgl. Our work therefore highlights act parallel antagonize apical determinants.