Magi Is Associated with the Par Complex and Functions Antagonistically with Bazooka to Regulate the Apical Polarity Complex
Fig 8
A balance between the levels of Magi and Baz regulates aPKC membrane levels.
apterous-GAL4 was used to overexpress different combinations of tagged proteins in the wing imaginal disc. The average membrane intensity of each protein was measured and compared between the apterous (black bars) and non-apterous (white bars) side of the wing imaginal disc. The white lines mark the apterous dorsal/ventral boundary. (A-H) Overexpression of aPKC::GFP (green) had no effect on the membrane localization or levels of Magi (red) (A-D) or Baz (red) (E-H). (I-L) Co-expression of Magi::Cherry (blue) and Baz::GFP (green) attenuated the changes in aPKC (red) caused by high levels of Baz or Magi alone. aPKC levels were not increased by overexpression of Baz::GFP when Magi::Cherry was co-expressed. (M-P) Coexpression of Magi::Cherry (blue) and aPKC::GFP (green) lead to a reduction in the Baz membrane levels (red) and increased accumulation in the Magi vesicles. Overexpression of wildtype aPKC did not block the Magi induced reduction in Baz. (Q-X) Higher resolution image of the large accumulations seen with Magi::Cherry expression at the basolateral region of the epithelial cells. Each panel was digitally magnified 200%. (Q-T) Co-expression of Magi::Cherry (blue) and Baz::GFP (green) lead to the accumulation of Baz and Magi within the large internal accumulations. aPKC (red) was only weakly recruited (arrows). (U-X) Co-expression of Magi::Cherry (blue) and aPKC::GFP (green) lead to an increased accumulation of Magi vesicles that were also positive for Baz (red) (arrows). *** p<0.001; * p<0.05; ns not significant. Error bars indicate SEM. n = 5 discs for each experiment. Scale bars indicate 5μm for A-O and 2μm for Q-X.