Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/94153

Title

Profilin interaction with phosphatidylinositol (4,5)-bisphosphate destabilizes the membrane of giant unilamellar vesicles

Author(s)

Krishnan, Kannan;  Holub, Oliver;  Gratton, Enrico;  Clayton, Andrew H. A.;  Cody, Stephen;  Moens, Pierre D. J.

Abstract

Profilin, a small cytoskeletal protein, and phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] have been implicated in cellular events that alter the cell morphology, such as endocytosis, cell motility, and formation of the cleavage furrow during cytokinesis. Profilin has been shown to interact with PI(4,5)P2, but the role of this interaction is still poorly understood. Using giant unilamellar vesicles (GUVs) as a simple model of the cell membrane, we investigated the interaction between profilin and PI(4,5)P2. A number and brightness analysis demonstrated that in the absence of profilin, molar ratios of PI(4,5)P2 above 4% result in lipid demixing and cluster formations. Furthermore, adding profilin to GUVs made with 1% PI(4,5)P2 leads to the formation of clusters of both profilin and PI(4,5)P2. However, due to the self-quenching of the dipyrrometheneboron difluoride-labeled PI(4,5)P2, we were unable to determine the size of these clusters. Finally, we show that the formation of these clusters results in the destabilization and deformation of the GUV membrane.

Publication type

Journal article

Source

Biophysical Journal, Vol. 96, no. 12 (Jun 2009), pp. 5112-5121

Publication year

2009

FOR Code(s)

0299 Other Physical Sciences;  0903 Biomedical Engineering

Keyword(s)

Dipyrrometheneboron difluoride;  Phosphatidylinositol (4,5) bisphosphate;  Profilins;  Protein binding;  Protein interaction;  Unilamellar liposomes

Publisher

Elsevier

ISSN

0006-3495

Publisher URL

http://dx.doi.org/10.1016/j.bpj.2009.03.034

Copyright

Copyright © 2009 by the Biophysical Society (published by Elsevier).

Peer reviewed