Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Cell Biol. 2004 Aug 16;166(4):549-57. Epub 2004 Aug 9.

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

Author information

  • 1Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Cientificas and Univerisidad Autonoma de Madrid, Cantoblanco, 28049 Madrid, Spain.

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.

PMID:
15302858
[PubMed - indexed for MEDLINE]
PMCID:
PMC2172211
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk