Three-dimensional analysis of post-Golgi carrier exocytosis in epithelial cells Academic Article uri icon


MeSH Major

  • Cell Membrane
  • Epithelial Cells
  • Exocytosis
  • Golgi Apparatus
  • Protein Transport


  • Targeted delivery of proteins to distinct plasma membrane domains is critical to the development and maintenance of polarity in epithelial cells. We used confocal and time-lapse total internal reflection fluorescence microscopy (TIR-FM) to study changes in localization and exocytic sites of post-Golgi transport intermediates (PGTIs) carrying GFP-tagged apical or basolateral membrane proteins during epithelial polarization. In non-polarized Madin Darby Canine Kidney (MDCK) cells, apical and basolateral PGTIs were present throughout the cytoplasm and were observed to fuse with the basal domain of the plasma membrane. During polarization, apical and basolateral PGTIs were restricted to different regions of the cytoplasm and their fusion with the basal membrane was completely abrogated. Quantitative analysis suggested that basolateral, but not apical, PGTIs fused with the lateral membrane in polarized cells, correlating with the restricted localization of Syntaxins 4 and 3 to lateral and apical membrane domains, respectively. Microtubule disruption induced Syntaxin 3 depolarization and fusion of apical PGTIs with the basal membrane, but affected neither the lateral localization of Syntaxin 4 or Sec6, nor promoted fusion of basolateral PGTIs with the basal membrane.

publication date

  • February 2003



  • Academic Article



  • eng

Digital Object Identifier (DOI)

  • 10.1038/ncb917

PubMed ID

  • 12545172

Additional Document Info

start page

  • 126

end page

  • 36


  • 5


  • 2