These authors contributed equally to this work.
Lipid Cosorting Mediated by Shiga Toxin Induced Tubulation
Article first published online: 30 SEP 2010
© 2010 John Wiley & Sons A/S
Volume 11, Issue 12, pages 1519–1529, December 2010
How to Cite
Safouane, M., Berland, L., Callan-Jones, A., Sorre, B., Römer, W., Johannes, L., Toombes, G. E. S. and Bassereau, P. (2010), Lipid Cosorting Mediated by Shiga Toxin Induced Tubulation. Traffic, 11: 1519–1529. doi: 10.1111/j.1600-0854.2010.01116.x
- Issue published online: 12 NOV 2010
- Article first published online: 30 SEP 2010
- Accepted manuscript online: 7 SEP 2010 12:00AM EST
- Received 6 April 2010, revised and accepted for publication 30 August 2010, uncorrected manuscript published online 7 September 2010, published online 1 October 2010
- lipid sorting;
- model membrane;
- Shiga toxin;
To maintain cell membrane homeostasis, lipids must be dynamically redistributed during the formation of transport intermediates, but the mechanisms driving lipid sorting are not yet fully understood. Lowering sphingolipid concentration can reduce the bending energy of a membrane, and this effect could account for sphingolipid depletion along the retrograde pathway. However, sphingolipids and cholesterol are enriched along the anterograde pathway, implying that other lipid sorting mechanisms, such as protein-mediated sorting, can dominate. To characterize the influence of protein binding on the lipid composition of highly curved membranes, we studied the interactions of the B-subunit of Shiga toxin (STxB) with giant unilamellar vesicles containing its glycosphingolipid receptor [globotriaosylceramide (Gb3)]. STxB binding induced the formation of tubular membrane invaginations, and fluorescence microscopy images of these highly curved membranes were consistent with co-enrichment of Gb3 and sphingolipids. In agreement with theory, sorting was stronger for membrane compositions close to demixing. These results strongly support the hypothesis that proteins can indirectly mediate the sorting of lipids into highly curved transport intermediates via interactions between lipids and the membrane receptor of the protein.