Work

DaPKC-dependent phosphorylation of Crumbs is required for epithelial cell polarity in Drosophila

Year: 2004

Type: article

Abstract: Both in Drosophila and vertebrate epithelial cells, the establishment of apicobasal polarity requires the apically localized, membrane-associated Par-3-Par-6-aPKC protein complex. In Drosophila, this complex colocalizes with the Crumbs-Stardust (Sdt)-Pals1-associated TJ protein (Patj) complex. Genetic and molecular analyses suggest a functional relationship between them. We show, by overexpression of a kinase-dead Drosophila atypical PKC (DaPKC), the requirement for the kinase activity of DaPKC to maintain the position of apical determinants and to restrict the localization of basolateral ones. We demonstrate a novel physical interaction between the apical complexes, via direct binding of DaPKC to both Crb and Patj, and identify Crumbs as a phosphorylation target of DaPKC. This phosphorylation of Crumbs is functionally significant. Thus, a nonphosphorylatable Crumbs protein behaves in vivo as a dominant negative. Moreover, the phenotypic effect of overexpressing wild-type Crumbs is suppressed by reducing DaPKC activity. These results provide a mechanistic framework for the functional interaction between the Par-3-Par-6-aPKC and Crumbs-Sdt-Patj complexes based in the posttranslational modification of Crb by DaPKC.

Source: The Journal of Cell Biology

DOI: 10.1083/jcb.200311031

Authors: Sol Sotillos, María Teresa Díaz-Meco, Eva Caminero, Jorge Moscat, Sonsoles Campuzano

Institutions: Consejo Superior de Investigaciones Científicas, Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid

Language: English

Topic: Developmental Biology and Gene Regulation

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze