Load Adaptation of Lamellipodial Actin Networks

Article Article scientifique Article Load Adaptation of Lamellipodial Actin Networks eng 2017 author Mueller Jan Felix 519726 author Szep Gregory author Nemethova Maria author de Vries Ingrid author Lieber Arnon D. author Winkler Christoph Heinrich 89017 author Kruse Karsten 861969 author Small J. Victor author Schmeiser Christian author Keren Kinneret author Hauschild Robert author Sixt Michael 188-200.e16 10.1016/j.cell.2017.07.051 0092-8674 https://linkinghub.elsevier.com/retrieve/pii/S0092867417308887 Actin filaments polymerizing against membranes power endocytosis, vesicular traffic, and cell motility. In vitro reconstitution studies suggest that the structure and the dynamics of actin networks respond to mechanical forces. We demonstrate that lamellipodial actin of migrating cells responds to mechanical load when membrane tension is modulated. In a steady state, migrating cell filaments assume the canonical dendritic geometry, defined by Arp2/3-generated 70° branch points. Increased tension triggers a dense network with a broadened range of angles, whereas decreased tension causes a shift to a sparse configuration dominated by filaments growing perpendicularly to the plasma membrane. We show that these responses emerge from the geometry of branched actin: when load per filament decreases, elongation speed increases and perpendicular filaments gradually outcompete others because they polymerize the shortest distance to the membrane, where they are protected from capping. This network-intrinsic geometrical adaptation mechanism tunes protrusive force in response to mechanical load. Cytoskeleton Actin network Actin dynamics Cell migration Membrane tension Keratocyte Lamellipodium Correlated electron tomography Cell mechanics Dewey 500.2 Dewey 540 37 Département de physique théorique 133 39 Département de biochimie 144 false Cell 171 1 007c4e3a-eee8-4da5-86b3-c159bc01e317 Article (Published version) Public Load_KK_17.pdf 13993323 application/pdf openAccess Faculté des sciences / Section de physique / Département de physique théorique Faculté des sciences / Section de chimie et biochimie / Département de biochimie

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Load Adaptation of Lamellipodial Actin Networks	Cell			2017	398	378

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Mueller, Jan Felix