Journal article
Vinculin Nucleates Actin Polymerization and Modifies Actin Filament Structure
The Journal of biological chemistry, Vol.284(44), pp.30463-30473
10/30/2009
DOI: 10.1074/jbc.M109.021295
PMCID: PMC2781601
PMID: 19736312
Abstract
Vinculin links integrins to the actin cytoskeleton by binding F-actin. Little is known with respect to how this interaction occurs or affects actin dynamics. Here we assess the consequence of the vinculin tail (VT) on actin dynamics by examining its binding to monomeric and filamentous yeast actins. VT causes pyrene-labeled G-actin to polymerize in low ionic strength buffer (G-buffer), conditions that normally do not promote actin polymerization. Analysis by electron microscopy shows that, under these conditions, the filaments form small bundles at low VT concentrations, which gradually increase in size until saturation occurs at a ratio of 2 VT:1 actin. Addition of VT to pyrene-labeled mutant yeast G-actin (S265C) produced a fluorescence excimer band, which requires a relatively normal filament geometry. In higher ionic strength polymerization-promoting F-buffer, substoichiometric amounts of VT accelerate the polymerization of pyrene-labeled WT actin. However, the amplitude of the pyrene fluorescence caused by actin polymerization is quenched as the VT concentration increases without an effect on net actin polymerization as determined by centrifugation assays. Finally, addition of VT to preformed pyrene-labeled S265C F-actin causes a concentration-dependent decrease in the maximum amplitude of the pyrene fluorescence band demonstrating the ability of VT to remodel the conformation of the actin filament. These observations support the idea that vinculin can link adhesion plaques to the cytoskeleton by initiating the formation of bundled actin filaments or by remodeling existing filaments.
Details
- Title: Subtitle
- Vinculin Nucleates Actin Polymerization and Modifies Actin Filament Structure
- Creators
- Kuo-Kuang Wen - From the Department of Biochemistry, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242Peter A Rubenstein - From the Department of Biochemistry, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242Kris A DeMali - From the Department of Biochemistry, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa 52242
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.284(44), pp.30463-30473
- DOI
- 10.1074/jbc.M109.021295
- PMID
- 19736312
- PMCID
- PMC2781601
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- American Society for Biochemistry and Molecular Biology; 9650 Rockville Pike, Bethesda, MD 20814, U.S.A
- Grant note
- 1K01CA111818; GM33689 / National Institutes of Health
- Language
- English
- Date published
- 10/30/2009
- Academic Unit
- Dermatology; Stead Family Department of Pediatrics; Fraternal Order of Eagles Diabetes Research Center; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984024531702771
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