Mutant rat phosphatidylinositol/phosphatidylcholine transfer proteins specifically defective in phosphatidylinositol transfer: implications for the regulation of phospholipid transfer activity. Academic Article uri icon


  • The mammalian phosphatidylinositol/phosphatidylcholine transfer proteins (PI-TPs) catalyze exchange of phosphatidylinositol (PI) or phosphatidylcholine (PC) between membrane bilayers in vitro. We find that Ser-25, Thr-59, Pro-78, and Glu-248 make up a set of rat (r) PI-TP residues, substitution of which effected a dramatic reduction in the relative specific activity for PI transfer activity without significant effect on PC transfer activity. Thr-59 was of particular interest as it is a conserved residue in a highly conserved consensus protein kinase C phosphorylation motif in metazoan PI-TPs. Replacement of Thr-59 with Ser, Gln, Val, Ile, Asn, Asp, or Glu effectively abolished PI transfer capability but was essentially silent with respect to PC transfer activity. These findings identify rPI-TP residues that likely cooperate to form a PI head-group binding/recognition site or that lie adjacent to such a site. Finally, the selective sensitivity of the PI transfer activity of rPI-TP to alteration of Thr-59 suggests a mechanism for in vivo regulation of rPI-TP activity.

published proceedings

  • Proc Natl Acad Sci U S A

altmetric score

  • 3

author list (cited authors)

  • Alb, J. G., Gedvilaite, A., Cartee, R. T., Skinner, H. B., & Bankaitis, V. A.

citation count

  • 55

complete list of authors

  • Alb, JG||Gedvilaite, A||Cartee, RT||Skinner, HB||Bankaitis, VA

publication date

  • September 1995