Vinculin plays a fundamental role in integrin-mediated cell adhesion. Activated by talin, it interacts with diverse adhesome components, enabling mechanical coupling between the actin cytoskeleton and the extracellular matrix. Here we studied the interactions of activated full-length vinculin with actin and the way it regulates the organization and dynamics of the Arp2/3 complex-mediated branched actin network. Through a combination of surface patterning and light microscopy experiments we show that vinculin can bundle dendritic actin networks through rapid binding and filament crosslinking. We show that vinculin promotes stable but flexible actin bundles having a mixed-polarity organization, as confirmed cryo-electron tomography. Adhesion-like synthetic design of vinculin activation by surface-bound talin revealed that clustered vinculin can initiate and immobilize bundles from mobile Arp2/3-branched networks. Our results provide a molecular basis for coordinate actin bundle formation at nascent adhesions.
All data generated or analysed during this study are included in the manuscript and supporting files. The structural data is deposited to the EMD , access number EMD-10737, and two tomographic volumes were deposited in EMPIAR under the accession number EMPIAR-10548.
Actin filament structure from vinculin-induced bundlesEMDB, EMD-10737.
Talin-activated vinculin interacts with branched actin networks to initiate bundlesEMPIAR , EMPIAR-10548.
Near-Atomic Resolution for One State of F-ActinEMDB, EMD-6179.
- Ohad Medalia
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Edward H Egelman, University of Virginia, United States
© 2020, Boujemaa-Paterski et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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