Multiple actin binding domains of Ena/VASP proteins determine actin network stiffening
| Autor: | Brian Gentry, Stef A. J. van der Meulen, Julie Plastino, Gijsje H. Koenderink, Philippe Noguera, Baldomero Alonso-Latorre |
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| Přispěvatelé: | Physics of Living Systems, LaserLaB - Molecular Biophysics |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Biophysics
Plasma protein binding macromolecular substances Protein filament Mice Elastic Modulus Animals Protein Interaction Domains and Motifs Actin-binding protein Binding site Cytoskeleton Actin Binding Sites biology Chemistry Microfilament Proteins Actin remodeling General Medicine Phosphoproteins Actins Actin Cytoskeleton Biochemistry Phosphoprotein Mutation biology.protein Protein Multimerization Cell Adhesion Molecules Protein Binding |
| Zdroj: | European Biophysics Journal, 41(11), 979-990. Springer Verlag Gentry, B S, van der Meulen, S, Noguera, P, Alonso-Latorre, B, Plastino, J & Koenderink, G H 2012, ' Multiple actin binding domains of Ena/VASP proteins determine actin network stiffening ', European Biophysics Journal, vol. 41, no. 11, pp. 979-990 . https://doi.org/10.1007/s00249-012-0861-1 |
| ISSN: | 0175-7571 |
| DOI: | 10.1007/s00249-012-0861-1 |
| Popis: | Vasodilator-stimulated phosphoprotein (Ena/ VASP) is an actin binding protein, important for actin dynamics in motile cells and developing organisms. Though VASP's main activity is the promotion of barbed end growth, it has an F-actin binding site and can form tetramers, and so could additionally play a role in actin crosslinking and bundling in the cell. To test this activity, we performed rheology of reconstituted actin networks in the presence of wild-type VASP or mutants lacking the ability to tetramerize or to bind G-actin and/or F-actin. We show that increasing amounts of wild-type VASP increase network stiffness up to a certain point, beyond which stiffness actually decreases with increasing VASP concentration. The maximum stiffness is 10-fold higher than for pure actin networks. Confocal microscopy shows that VASP forms clustered actin filament bundles, explaining the reduction in network elasticity at high VASP concentration. Removal of the tetramerization site results in significantly reduced bundling and bundle clustering, indicating that VASP's flexible tetrameric structure causes clustering. Removing either the F-actin or the G-actin binding site diminishes VASP's effect on elasticity, but does not eliminate it. Mutating the F-actin and G-actin binding site together, or mutating the F-actin binding site and saturating the G-actin binding site with monomeric actin, eliminates VASP's ability to increase network stiffness. We propose that, in the cell, VASP crosslinking confers only moderate increases in linear network elasticity, and unlike other crosslinkers, VASP's network stiffening activity may be tuned by the local concentration of monomeric actin. © European Biophysical Societies' Association 2012. |
| Databáze: | OpenAIRE |
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