Abstract
The present study has re-evaluated the mobility of glycoprotein Ib/IX (GPIb/IX), the von Willebrand factor receptor, on surface-activated platelets. A previous report employing immunogold cytochemistry with monoclonal and polyclonal antibodies specific for GPIb/IX concluded that the receptor remained stabilized in plasma membranes and did not move during platelet attachment and spreading on formvar grids, despite the observation that immunogold particles marking GPIb/IX were missing from peripheral margins and pseudopods of the surface-activated platelets. Addition of thrombin to surface-activated, spread platelets freed GPIb/IX from its anchor to the membrane and stimulated movement of receptor-ligand complexes into caps over centers of spread platelets. In our investigation, surface-activated platelets, stimulated or not by thrombin, were fixed in a higher concentration of glutaraldehyde than used by the earlier workers before exposure to monoclonal or polyclonal antibody to GPIb/IX, after incubation with the antibody, but before treatment with the immunogold marker, protein A gold (PAG), or after both antibody and PAG. When fixed before exposure to antibody and PAG, GPIb/IX receptors were dispersed evenly over dendritic and spread platelets from edge to edge, including peripheral margins and pseudopods. Thrombin had no influence on distribution of the receptors. Exposure to antiglycocalicin antibody before fixation caused movement of GPIb/IX receptors from peripheral margins of spread cells and pseudopods of dendritic forms. Thrombin treatment did not enhance the movement. Fixation after exposure of surface-activated platelets, treated or not with thrombin, to antibody and PAG caused movement of GPIb/IX receptors into caps over cell centers. Results indicate that central movement of GPIb/IX receptors is unrelated to surface activation, spreading, or thrombin stimulation. Rather, the translocation is caused by the antiglycocalicin antibody and accentuated by PAG.
Full text
PDF










Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Albrecht R. M., Goodman S. L., Simmons S. R. Distribution and movement of membrane-associated platelet glycoproteins: use of colloidal gold with correlative video-enhanced light microscopy, low-voltage high-resolution scanning electron microscopy, and high-voltage transmission electron microscopy. Am J Anat. 1989 Jun-Jul;185(2-3):149–164. doi: 10.1002/aja.1001850208. [DOI] [PubMed] [Google Scholar]
- Escolar G., Clemetson K., White J. G. Persistence of mobile receptors on surface- and suspension-activated platelets. J Lab Clin Med. 1994 Apr;123(4):536–546. [PubMed] [Google Scholar]
- Escolar G., Leistikow E., White J. G. The fate of the open canalicular system in surface and suspension-activated platelets. Blood. 1989 Nov 1;74(6):1983–1988. [PubMed] [Google Scholar]
- Escolar G., White J. G. Organization of von Willebrand factor on surface-activated platelets. Arterioscler Thromb. 1993 Dec;13(12):1852–1858. doi: 10.1161/01.atv.13.12.1852. [DOI] [PubMed] [Google Scholar]
- Fox J. E. Identification of actin-binding protein as the protein linking the membrane skeleton to glycoproteins on platelet plasma membranes. J Biol Chem. 1985 Oct 5;260(22):11970–11977. [PubMed] [Google Scholar]
- Fox J. E. Linkage of a membrane skeleton to integral membrane glycoproteins in human platelets. Identification of one of the glycoproteins as glycoprotein Ib. J Clin Invest. 1985 Oct;76(4):1673–1683. doi: 10.1172/JCI112153. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fox J. E., Reynolds C. C., Phillips D. R. Calcium-dependent proteolysis occurs during platelet aggregation. J Biol Chem. 1983 Aug 25;258(16):9973–9981. [PubMed] [Google Scholar]
- Gerrard J. M., Phillips D. R., Rao G. H., Plow E. F., Walz D. A., Ross R., Harker L. A., White J. G. Biochemical studies of two patients with the gray platelet syndrome. Selective deficiency of platelet alpha granules. J Clin Invest. 1980 Jul;66(1):102–109. doi: 10.1172/JCI109823. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hourdillé P., Gralnick H. R., Heilmann E., Derlon A., Ferrer A. M., Vezon G., Nurden A. T. von Willebrand factor bound to glycoprotein Ib is cleared from the platelet surface after platelet activation by thrombin. Blood. 1992 Apr 15;79(8):2011–2021. [PubMed] [Google Scholar]
- Hourdillé P., Heilmann E., Combrié R., Winckler J., Clemetson K. J., Nurden A. T. Thrombin induces a rapid redistribution of glycoprotein Ib-IX complexes within the membrane systems of activated human platelets. Blood. 1990 Oct 15;76(8):1503–1513. [PubMed] [Google Scholar]
- Kieffer N., Guichard J., Breton-Gorius J. Dynamic redistribution of major platelet surface receptors after contact-induced platelet activation and spreading. An immunoelectron microscopy study. Am J Pathol. 1992 Jan;140(1):57–73. [PMC free article] [PubMed] [Google Scholar]
- Loftus J. C., Albrecht R. M. Redistribution of the fibrinogen receptor of human platelets after surface activation. J Cell Biol. 1984 Sep;99(3):822–829. doi: 10.1083/jcb.99.3.822. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Olorundare O. E., Simmons S. R., Albrecht R. M. Evidence for two mechanisms of ligand-receptor movement on surface-activated platelets. Eur J Cell Biol. 1993 Feb;60(1):131–145. [PubMed] [Google Scholar]
- White J. G., Burris S. M., Hasegawa D., Johnson M. Micropipette aspiration of human blood platelets: a defect in Bernard-Soulier's syndrome. Blood. 1984 May;63(5):1249–1252. [PubMed] [Google Scholar]
- White J. G., Escolar G. Fibrinogen receptors do not undergo spontaneous redistribution on surface-activated platelets. Arteriosclerosis. 1990 Sep-Oct;10(5):738–744. doi: 10.1161/01.atv.10.5.738. [DOI] [PubMed] [Google Scholar]
- White J. G. Interaction of membrane systems in blood platelets. Am J Pathol. 1972 Feb;66(2):295–312. [PMC free article] [PubMed] [Google Scholar]
- White J. G., Krumwiede M. D., Cocking-Johnson D., Escolar G. Induction of GPIb/IX-vWF receptor-ligand translocation on surface-activated platelets. Arterioscler Thromb Vasc Biol. 1995 May;15(5):642–654. doi: 10.1161/01.atv.15.5.642. [DOI] [PubMed] [Google Scholar]
- White J. G., Krumwiede M., Cocking-Johnson D., Escolar G. Influence of combined thrombin stimulation, surface activation, and receptor occupancy on organization of GPIb/IX receptors on human platelets. Br J Haematol. 1994 Sep;88(1):137–148. doi: 10.1111/j.1365-2141.1994.tb04989.x. [DOI] [PubMed] [Google Scholar]
- White J. G. Views of the platelet cytoskeleton at rest and at work. Ann N Y Acad Sci. 1987;509:156–176. doi: 10.1111/j.1749-6632.1987.tb30993.x. [DOI] [PubMed] [Google Scholar]
















