VASP mediated actin dynamics activate and recruit a filopodia myosin
Abstract
Filopodia are thin, actin-based structures that cells use to interact with their environments. Filopodia initiation requires a suite of conserved proteins but the mechanism remains poorly understood. The actin polymerase VASP and a MyTH-FERM (MF) myosin, DdMyo7 in amoeba, are essential for filopodia initiation. DdMyo7 is localized to dynamic regions of the actin-rich cortex. Analysis of VASP mutants and treatment of cells with anti-actin drugs shows that myosin recruitment and activation in Dictyostelium requires localized VASP-dependent actin polymerization. Targeting of DdMyo7 to the cortex alone is not sufficient for filopodia initiation; VASP activity is also required. The actin regulator locally produces a cortical actin network that activates myosin and together they shape the actin network to promote extension of parallel bundles of actin during filopodia formation. This work reveals how filopodia initiation requires close collaboration between an actin binding protein, the state of the actin cytoskeleton and MF myosin activity.
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All data generated or analyzed during this study are included in the manuscript and supporting files.
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Funding
Centre National de la Recherche Scientifique
- Anne Houdusse
Agence Nationale de la Recherche (ANR-17-CE11-0029-01)
- Anne Houdusse
Agence Nationale de la Recherche (LabexCelTisPhyBio 11-LBX-0038)
- Anne Houdusse
Agence Nationale de la Recherche (ANR-10-IDEX-0001-02PSL)
- Anne Houdusse
National Institutes of Health (F31GM128325)
- Ashley L Arthur
National Institutes of Health (R01GM122917)
- Margaret A Titus
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Arthur 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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