Cellular and Molecular Life Sciences CMLS

, Volume 62, Issue 13, pp 1514–1525

Activated scramblase and inhibited aminophospholipid translocase cause phosphatidylserine exposure in a distinct platelet fraction

  • J. L. N. Wolfs
  • P. Comfurius
  • J. T. Rasmussen
  • J. F. W. Keuren
  • T. Lindhout
  • R. F. A. Zwaal
  • E. M. Bevers
Research Article

DOI: 10.1007/s00018-005-5099-y

Cite this article as:
Wolfs, J.L.N., Comfurius, P., Rasmussen, J.T. et al. CMLS, Cell. Mol. Life Sci. (2005) 62: 1514. doi:10.1007/s00018-005-5099-y

Abstract.

Platelet procoagulant activity is mainly determined by the extent of surface-exposed phosphatidylserine (PS), controlled by the activity of aminophospholipid translocase and phospholipid scramblase. Here, we studied both transport activities in single platelets upon stimulation with various agonists. Besides the formation of procoagulant microparticles, the results show that a distinct fraction of the platelets exposes PS when stimulated. The extent of PS exposure in these platelet fractions was similar to that in platelets challenged with Ca2+-ionophore, where all cells exhibit maximal attainable PS exposure. The size of the PS-exposing fraction depends on the agonist and is proportional to the platelet procoagulant activity. Scramblase activity was observed only in the PS-exposing platelet fraction, whereas translocase activity was exclusively detectable in the fraction that did not expose PS. We conclude that, irrespective of the agonist, procoagulant platelets exhibit maximal surface exposure of PS by switching on scramblase and inhibiting translocase activity.

Key words.

Procoagulant activityscramblaseaminophospholipid translocasethrombincollagenplateletphosphatidylserinemicroparticle

Copyright information

© Birkhäuser Verlag, Basel 2005

Authors and Affiliations

  • J. L. N. Wolfs
    • 1
  • P. Comfurius
    • 1
  • J. T. Rasmussen
    • 2
  • J. F. W. Keuren
    • 3
  • T. Lindhout
    • 1
  • R. F. A. Zwaal
    • 1
  • E. M. Bevers
    • 1
  1. 1.Department of Biochemistry, Cardiovascular Research Institute MaastrichtMaastricht UniversityMaastrichtThe Netherlands
  2. 2.Protein Chemistry Laboratory, Department of Molecular BiologyUniversity of AarhusDenmark
  3. 3.Sanquin, Blood Bank Region South-EastMaastrichtThe Netherlands