TY - JOUR TI - Talin-activated vinculin interacts with branched actin networks to initiate bundles AU - Boujemaa-Paterski, Rajaa AU - Martins, Bruno AU - Eibauer, Matthias AU - Beales, Charlie T AU - Geiger, Benjamin AU - Medalia, Ohad A2 - Egelman, Edward H A2 - Pfeffer, Suzanne R A2 - Ballestrem, Christoph VL - 9 PY - 2020 DA - 2020/11/13 SP - e53990 C1 - eLife 2020;9:e53990 DO - 10.7554/eLife.53990 UR - https://doi.org/10.7554/eLife.53990 AB - 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 by 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. KW - vinculin KW - actin KW - confocal microscopy KW - cryo-elecron tomography JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -