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
Publication Date
2009
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.
Citation
Biophysical Journal, 96(12), p. 5112-5121
ISSN
1542-0086
0006-3495
Link
Publisher
Elsevier Inc
Title
Profilin Interaction with Phosphatidylinositol (4,5)-Bisphosphate Destabilizes the Membrane of Giant Unilamellar Vesicles
Type of document
Journal Article
Entity Type
Publication

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