Vectorial apical delivery and slow endocytosis of a glycolipid-anchored fusion protein in transfected MDCK cells Academic Article uri icon


MeSH Major

  • Endocytosis
  • Glycolipids
  • Phosphatidylinositols
  • Viral Envelope Proteins


  • To characterize the mechanisms that determine the apical polarity of proteins anchored by glycosylphosphatidylinositol (GPI), we studied the targeting of a GPI-anchored form of a herpes simplex glycoprotein, gD-1, in transfected MDCK cells. Using a biotin-based targeting assay, we found that GPI-anchored gD-1 was sorted intracellularly and delivered directly to the apical surface. Endocytosis of GPI-anchored gD-1 occurred slowly and preferentially from the apical domain, while transcytosis of the basolateral fraction did not occur at a significant rate (incompatible with being a precursor to the apical pool). Prevention of tight junction formation by incubation in medium with micromolar Ca2+ resulted in expression of GPI-anchored gD-1 on the free surface, but not on the attached surface of the cell. Our results indicate that the apical polarity of a GPI-anchored protein is generated by vectorial delivery to the apical membrane, where its distribution is maintained by slow endocytosis and by a retention system not necessarily involving the tight junction.

publication date

  • December 1990



  • Academic Article



  • eng

PubMed Central ID

  • PMC54758

PubMed ID

  • 2145577

Additional Document Info

start page

  • 7419

end page

  • 23


  • 87


  • 19