Regensburg 2013 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 9: Posters: Membranes

BP 9.4: Poster

Montag, 11. März 2013, 17:30–19:30, Poster B2

A physical description of actin-driven filopodia growth — •Denis Johann and Karsten Kruse — Uni Saarland, Postfach 151150, 66041 Saarbrücken, Germany

Filopodia are cytoskeleton-driven fingerlike protrusions of eukaryotic cells that are filled with actin filaments. Motivated by these structures, we investigate the length distribution of membrane protrusions driven by treadmilling filaments growing at the tip and disassembling at the base. To this end we use a continuum mean-field equation for the treadmilling filaments and their constituting subunits as well as for the membrane that is characterized by its surface tension and its bending rigidity. The coupling between the membrane and the cytoskeleton is mediated by an effective potential. Using a GPU-based parallelized algorithm, we find that this system can create stationary filopodia lengths. This length increases linearly with the concentration of free monomers at the bottom of the filopodia, but also depends on the kinetic parameters governing filament assembly and disassembly as well as the mechanical properties of the membrane. Finally, we characterize the filament length distribution in steady state.