title: Myosin motors fragment and compact membrane-bound actin filaments.
abstract: Cell cortex remodeling during cell division is a result of myofilament-driven contractility of the cortical membrane-bound actin meshwork. Little is known about the interaction between individual myofilaments and membrane-bound actin filaments. Here we reconstituted a minimal actin cortex to directly visualize the action of individual myofilaments on membrane-bound actin filaments using TIRF microscopy. We show that synthetic myofilaments fragment and compact membrane-bound actin while processively moving along actin filaments. We propose a mechanism by which tension builds up between the ends of myofilaments, resulting in compressive stress exerted to single actin filaments, causing their buckling and breakage. Modeling of this mechanism revealed that sufficient force (∼20 pN) can be generated by single myofilaments to buckle and break actin filaments. This mechanism of filament fragmentation and compaction may contribute to actin turnover and cortex reorganization during cytokinesis.DOI:http://dx.doi.org/10.7554/eLife.00116.001.
authors: Max Planck Institute of Biochemistry ,  Department of Cellular and Molecular Biophysics ,  Martinsried ,  Germany.
authors: Sven K
authors: SK
authors: Vogel
authors: Zdenek
authors: Z
authors: Petrasek
authors: Fabian
authors: F
authors: Heinemann
authors: Petra
authors: P
authors: Schwille
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D003198:Computer Simulation; D007700:Kinetics; D008954:Models, Biological; D009119:Muscle Contraction; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D009210:Myofibrils / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D011817:Rabbits
chemical_list: D000255:Adenosine Triphosphate; D009218:Myosins
keywords: Actin; Actin Cortex; Membrane; Myofilaments; Myosin; None; TIRF