The Drosophila homolog of the Exo84 exocyst subunit promotes apical epithelial identity Journal Article


Authors: Blankenship, J. T.; Fuller, M. T.; Zallen, J. A.
Article Title: The Drosophila homolog of the Exo84 exocyst subunit promotes apical epithelial identity
Abstract: The polarized architecture of epithelial tissues involves a dynamic balance between apical and basolateral membrane domains. Here we show that epithelial polarity in the Drosophila embryo requires the exocyst complex subunit homolog Exo84. Exo84 activity is essential for the apical localization of the Crumbs transmembrane protein, a key determinant of epithelial apical identity. Adherens junction proteins become mislocalized at the cell surface in Exo84 mutants in a pattern characteristic of defects in apical, but not basolateral, components. Loss of Crumbs from the cell surface precedes the disruption of Bazooka and Armadillo localization in Exo84 mutants. Moreover, Exo84 mutants display defects in apical cuticle secretion that are similar to crumbs mutants and are suppressed by a reduction in the basolateral proteins Dlg and Lgl. In Exo84 mutants at advanced stages of epithelial degeneration, apical and adherens junction proteins accumulate in an expanded recycling endosome compartment. These results suggest that epithelial polarity in the Drosophila embryo is actively maintained by exocyst-dependent apical localization of the Crumbs transmembrane protein.
Keywords: unclassified drug; mutation; nonhuman; protein function; protein localization; animals; cell structure; embryo; membrane proteins; drosophila; transcription factors; membrane glycoproteins; intracellular signaling peptides and proteins; membrane protein; epithelium cell; epithelial cells; cellular distribution; cell polarity; drosophila melanogaster; protein subunit; protein subunits; cell junction; cadherin; cadherins; drosophila proteins; armadillo domain protein; apical membrane; armadillo domain proteins; armadillo; cell surface protein; endosome; adherens junctions; vesicular transport proteins; protein lgl; apical-basal polarity; membrane structure; endosomes; epithelial polarity; exocyst complex; membrane trafficking; exocyst; protein crumbs; protein dlg
Journal Title: Journal of Cell Science
Volume: 120
Issue: 17
ISSN: 0021-9533
Publisher: Company of Biologists  
Date Published: 2007-09-01
Start Page: 3099
End Page: 3110
Language: English
DOI: 10.1242/jcs.004770
PUBMED: 17698923
PROVIDER: scopus
DOI/URL:
Notes: --- - "Cited By (since 1996): 33" - "Export Date: 17 November 2011" - "CODEN: JNCSA" - "Source: Scopus"
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MSK Authors
  1. Jennifer A Zallen
    39 Zallen