TY - JOUR TI - VASP-mediated actin dynamics activate and recruit a filopodia myosin AU - Arthur, Ashley L AU - Crawford, Amy AU - Houdusse, Anne AU - Titus, Margaret A A2 - Applewhite, Derek A2 - Akhmanova, Anna A2 - Applewhite, Derek A2 - Hansen, Scott VL - 10 PY - 2021 DA - 2021/05/27 SP - e68082 C1 - eLife 2021;10:e68082 DO - 10.7554/eLife.68082 UR - https://doi.org/10.7554/eLife.68082 AB - 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. KW - filopodia KW - actin dynamics KW - MyTH-FERM myosin KW - VASP KW - myosin autoinhibition JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -