Regensburg 2013 – scientific programme
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BP: Fachverband Biologische Physik
BP 24: Posters: Physics of Cells
BP 24.2: Poster
Wednesday, March 13, 2013, 17:30–19:30, Poster C
Causes of retrograde flow in fish keratocytes — •Thomas Fuhs1,2, Michael Goegler1, Claudia A. Brunner1, Charles W. Wolgemuth3, and Josef A. Kaes1 — 1Division of Soft Matter Physics, Department of Physics, University of Leipzig, Leipzig, Germany — 2Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany — 3Departments of Physics of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, United States of America
Confronting motile cells with obstacles doubling as force sensors we tested the limits of the driving actin-and-myosin-machinery. We could directly measure the force necessary to stop actin polymerization as well as the force present in the retrograde actin flow. Combined with detailed measurements of the retrograde flow velocity and specific manipulation of actin and myosin we found that actin polymerization and myosin contractility are not enough to explain the cells behavior. We show that ever-present depolymerization forces, a direct entropic consequence of actin filament recycling, are sufficient to fill this gap, even under heavy loads.