Phosphatidylinositol 3-kinase Regulation of Fluid Phase Endocytosis

FEBS Lett. 1995 Jul 3;367(3):272-4. doi: 10.1016/0014-5793(95)00576-u.


Endocytosis of the fluid phase marker, horse radish peroxidase, into baby hamster kidney cells is inhibited by treatment of cells with the fungal metabolite wortmannin. The IC50 of approximately 5 nM is consistent with the well-described action of wortmannin upon phosphatidylinositol (PI) 3-kinase. Analysis of the kinetics of uptake indicates a > 50% decrease in the initial rate of marker internalisation, a concomitant decrease in the volume of the early endosome and an increased efficiency of recycling of that marker which is internalised. As PI 3-kinase binds to activated growth factor receptors our data suggest that receptor activation can be coupled to receptor internalisation (down regulation) by localising PI 3-kinase stimulation of endocytosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Cell Line
  • Cricetinae
  • Endocytosis* / drug effects
  • In Vitro Techniques
  • Inositol Phosphates / physiology
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor) / physiology*
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Signal Transduction
  • Wortmannin


  • Androstadienes
  • Inositol Phosphates
  • Phosphatidylinositol 3-Kinases
  • Phosphotransferases (Alcohol Group Acceptor)
  • Receptor Protein-Tyrosine Kinases
  • Wortmannin