Dresden 2009 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 9: Actin Dynamics
BP 9.6: Vortrag
Dienstag, 24. März 2009, 12:15–12:30, ZEU 260
A realistic model for actin driven motility using homogenization techniques — •Karin John1, Denis Caillerie2, Philippe Peyla1, and Chaouqi Misbah1 — 1Laboratoire des Spectrométrie Physique, UJF Grenoble I, BP 87 - 38402 Saint-Martin-d'Hères, France — 2Laboratoire 3SR, INPG, BP 53 - 38041 Grenoble Cedex 9, France
Force generation by actin polymerization is an important step in cellular motility and can induce the motion of organelles or bacteria, which move inside their host cells by trailing an actin comet behind.
Biomimetic experiments on beads and droplets have identified the biochemical ingredients to induce this motion, which requires a spontaneous symmetry breaking in the absence of external fields.
We had shown previously, that the symmetry-breaking can be captured on the basis of a linear elasticity theory and linear flux-force relationships.
However, a deeper understanding of the process of symmetry-breaking and force generation necessitates a realistic description of the mechanics of the actin gel and its influence on the growth process.
Starting out from the filamentous structure of the actin gel we have derived a set of continuous constitutive equations using homogenization techniques, which takes into account the history of the gel growth.
This description allows us to capture basic phenomena like treadmilling, symmetry-breaking and comet formation without any ad hoc assumptions.