Sec6/8 complex is recruited to cell-cell contacts and specifies transport vesicle delivery to the basal-lateral membrane in epithelial cells

Cell. 1998 May 29;93(5):731-40. doi: 10.1016/s0092-8674(00)81435-x.


In budding yeast, the Sec6/8p complex is essential for generating cell polarity by specifying vesicle delivery to the bud tip. We show that Sec6/8 homologs are components of a cytosolic, approximately 17S complex in nonpolarized MDCK epithelial cells. Upon initiation of calcium-dependent cell-cell adhesion, approximately 70% of Sec6/8 is rapidly (t(1/2) approximately 3-6 hr) recruited to sites of cell-cell contact. In streptolysin-O-permeabilized MDCK cells, Sec8 antibodies inhibit delivery of LDL receptor to the basal-lateral membrane, but not p75NTR to the apical membrane. These results indicate that lateral membrane recruitment of the Sec6/8 complex is a consequence of cell-cell adhesion and is essential for the biogenesis of epithelial cell surface polarity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biological Transport
  • Carrier Proteins / metabolism*
  • Cell Adhesion Molecules / metabolism*
  • Cell Compartmentation
  • Cell Membrane / metabolism
  • Cell Polarity / physiology*
  • Dogs
  • Epithelial Cells / metabolism*
  • Golgi Apparatus / metabolism
  • Intercellular Junctions / physiology*
  • Intracellular Membranes / metabolism
  • Kidney / cytology
  • Lipoproteins, LDL / metabolism
  • Molecular Weight
  • Nerve Growth Factors / metabolism
  • Protein Binding


  • Carrier Proteins
  • Cell Adhesion Molecules
  • Lipoproteins, LDL
  • Nerve Growth Factors