A phosphatidylinositol 3-kinase and phosphatidylinositol transfer protein act synergistically in formation of constitutive transport vesicles from the trans-Golgi network. Academic Article uri icon


  • Current evidence suggests that phosphatidylinositol (PI) kinases and phosphatidylinositol transfer protein (PITP) are involved in driving vesicular traffic from yeast and mammalian trans-Golgi network (TGN). We have tested the interaction between these cytosolic proteins in an assay that measures the formation of constitutive transport vesicles from the TGN in a hepatocyte cell-free system. This reaction is dependent on a novel PI 3-kinase, and we now report that, under conditions of limiting cytosol, purified PI 3-kinase and PITP functionally cooperate to drive exocytic vesicle formation. This synergy was observed with both yeast and mammalian PITPs, and it also extended to the formation of PI 3-phosphate. These collective findings indicate that the PI 3-kinase and PITP synergize to form a pool of PI 3-phosphate that is essential for formation of exocytic vesicles from the hepatocyte TGN.

published proceedings

  • J Biol Chem

author list (cited authors)

  • Jones, S. M., Alb, J. G., Phillips, S. E., Bankaitis, V. A., & Howell, K. E.

citation count

  • 84

complete list of authors

  • Jones, SM||Alb, JG||Phillips, SE||Bankaitis, VA||Howell, KE

publication date

  • January 1998