|
|
 Previous Article | Table of Contents | Next Article 
Immunolocalization of beta 1 integrins in platelets and platelet- derived
microvesicles
JD Wencel-Drake, MG Dieter and SC Lam
Department of Medical Laboratory Sciences, University of Illinois, Chicago
60612.
Human platelets contain several adhesion receptors belonging to the
integrin superfamily. At least three beta 1 integrins are present on
platelets and have been shown to mediate platelet adhesion to collagen,
fibronectin, and laminin. To study the cellular localization of the beta 1
integrins in platelets, we produced a polyclonal antibody by immunization
of goat 172 with purified beta 1 subunit from HPB-ALL cells. Antibody 172
(Ab172) specifically immunoblotted a 135-Kd protein in a lysate of whole
platelets. The reactivity of Ab172 with platelet membrane proteins was
further determined by immunoprecipitation of lysates of
surface-radioiodinated platelets. Ab172 immunoprecipitates, resolved by
nonreducing/reducing two-dimensional sodium dodecyl sulfate- polyacrylamide
gel electrophoresis consisted of three labeled proteins with migrational
properties of platelet glycoprotein (GP)Ia, GPIc and GPIIa. Neither
GPIIb/IIIa nor the vitronectin receptor were immunoprecipitated by Ab172,
confirming a lack of cross-reactivity with the beta 3 integrins in
platelets. Immunofluorescence studies using Ab172 were performed to
investigate the cellular distribution of beta 1 integrins in platelets.
Fluorescent labeling of intact cells demonstrated the presence of beta 1
antigen on the surface of resting cells. Permeabilization of platelets with
Triton X-100 showed the presence of an intracellular pool of beta 1
antigen. Double-label experiments using Ab172 and AP-2 (anti-GPIIb/IIIa)
showed identical labeling patterns, suggesting a similar subcellular
distribution for these integrins. Following thrombin stimulation,
permeabilized cells showed a centralized clearing of both beta 1 antigen
and GPIIb/IIIa as well as an intensification of surface labeling for beta 1
antigen. These findings suggest the translocation of intracellular beta 1
antigen to the platelet surface as a result of thrombin stimulation.
Because platelet-derived microvesicles have been reported to contain
GPIIb/IIIa, we investigated the possible distribution of beta 1 integrins
in these structures. Microvesicles, produced as a result of platelet
activation, were labeled with Ab172, suggesting the distribution of beta 1
integrins in these structures as well as in intact cells.
Volume 82,
Issue 4,
pp. 1197-1203,
08/15/1993
Copyright © 1993 by The American Society of Hematology
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati What's this?
This article has been cited by other articles:
|
|
|
|
 
H. F.G. Heijnen, A. E. Schiel, R. Fijnheer, H. J. Geuze, and J. J. Sixma
Activated Platelets Release Two Types of Membrane Vesicles: Microvesicles by Surface Shedding and Exosomes Derived From Exocytosis of Multivesicular Bodies and alpha -Granules
Blood,
December 1, 1999;
94(11):
3791 - 3799.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y. Djellas, K. Antonakis, and G. C. Le Breton
A molecular mechanism for signaling between seven-transmembrane receptors: evidence for a redistribution of G proteins
PNAS,
September 1, 1998;
95(18):
10944 - 10948.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Aldo Del Maschio, I. Martin-Padura, S. Bernasconi, and E. Dejana
Triggering of ß1-Integrin Chain Induces Platelet Adhesion to Cultured Endothelium
Arterioscler. Thromb. Vasc. Biol.,
November 1, 1997;
17(11):
2663 - 2671.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
X.-N. Li, V. K. Varma, J. M. Parks, R. L. Benza, J. C. Koons, J. R. Grammer, H. Grenett, E. M. Tabengwa, and F. M. Booyse
Thrombin Decreases the Urokinase Receptor and Surface-Localized Fibrinolysis in Cultured Endothelial Cells
Arterioscler. Thromb. Vasc. Biol.,
March 1, 1995;
15(3):
410 - 419.
[Abstract]
[Full Text]
|
|
|
|
|
