Factor XII binding to endothelial cells depends on caveolae

European Journal of Biochemistry
I SchousboeBo van Deurs

Abstract

It is now generally accepted that factor XII (FXII) binds to cellular surfaces in the vascular system. One of the suggested receptors of this binding is the glycosylphosphatidylinositol-anchored urokinase-like plasminogen activator (u-PAR) harbored in caveolae/lipid rafts. However, binding of FXII to human umbilical vein endothelial cells (HUVEC) has never been shown to be localized to these specialized membrane structures. Using microscopical techniques, we here report that FXII binds to specific patches of the HUVEC plasma membrane with a high density of caveolae. Further investigations of FXII binding to caveolae were performed by sucrose density-gradient centrifugations. This showed that the majority of FXII, chemically cross-linked to HUVEC, could be identified in the same fractions of the gradient as caveolin-1, a marker of caveolae, while the majority of u-PAR was identified in noncaveolae lipid rafts. Accordingly, cholesterol-depleted cells were found to bind significantly reduced amounts of FXII. These observations, combined with the presence of a minority of u-PAR in caveolae concomitant with FXII binding, indicate that FXII binding to u-PAR may be secondary and depends upon the structural elements within caveolae. Th...Continue Reading

References

Jan 15, 1997·European Journal of Biochemistry·R Røjkjaer, I Schousboe
May 9, 1998·Proceedings of the National Academy of Sciences of the United States of America·A A HasanA H Schmaier
Dec 7, 2000·The Journal of Biological Chemistry·R L Chen, A D Lander
Jul 17, 2001·European Journal of Biochemistry·I Schousboe
Jul 12, 2002·Microscopy Research and Technique·Radu-Virgil Stan
Dec 14, 2002·The International Journal of Biochemistry & Cell Biology·Lars-Ake Fransson
Feb 1, 2003·Trends in Cell Biology·Bo van DeursKirsten Sandvig

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Citations

Sep 2, 2008·The Journal of Biological Chemistry·Sriram RavindranAnne George
Sep 8, 2012·Thrombosis and Haemostasis·Irma L A GeenenHenri M H Spronk
Mar 31, 2015·PloS One·Igor Z DamascenoGuacyara Motta

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