Fig. 4

αCat ABD mutants fail to rescue αCat function in Drosophila. a Phenotypic consequences of the overexpression of αCat ABD mutants and rescue activity of αCat ABD mutants expressed in αCat^−/− zygotic null mutants. Overexpression: all mutant constructs showed significantly reduced survival (P < 0.0001) compared to αCatFL overexpression. Rescue experiments: Mutant constructs showed a significant rescue (αCatFL, αCat-H1, αCat-Δα1, αCat-H1ΔβH [P < 0.0001]) or enhancement (αCat-3A [P < 0.0001], αCat-ΔABD [P = 0.0071]) of the αCat^−/− zygotic mutant phenotype. Expression of αCat-ΔβH did not significantly modify the αCat^−/− mutant phenotype. Data are presented as mean ± SD. b Cuticles of wild-type embryo, of αCat^−/− mutant showing failure in head morphogenesis (‘head open’; arrow), of αCat^−/− mutant expressing αCat-H1 showing a defective head skeleton (‘abnormal head’; arrow), and of αCat^−/− mutant expressing αCat-3A showing dorsal hole (arrow) in addition to an open head. c HA-tagged αCat variants were expressed with Act5c-Gal4 da-Gal4 in the epidermis of Drosophila embryos mutant for α-Cat (αCat^−/−) at stage 15. AJs marked by β-catenin. d Epidermal wounds in αCat^−/−, αCat^−/− mutant expressing αCatFL, and αCat^−/− mutant expressing αCat-H1. F-actin was labeled with GFP::UtrophinABD. Top panels show time of maximum wound area (yellow lines outline the wounds) and bottom panels show epidermis 30 min after wounding. Anterior left, dorsal up. Scale bar, 10 μm. e Wound area over time (left) and wound closure rate (right) for αCat^−/− (red, n = 12 wounds), αCat^−/− mutants expressing αCatFL (cyan, n = 10 wounds), and αCat^−/− mutants expressing αCat-H1 (green, n = 10 wounds). αCatFL, αCat^−/− embryos repaired damage to their epidermis significantly faster than αCat^−/− embryos (P = 0.027), whereas αCat-H1 αCat^−/− embryos did not show a significant difference to αCat^−/− embryos. The box plot shows the mean (gray line), SEM (box), and SD (black lines)