Dresden 2006 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 40: Poster Session II
AKB 40.55: Poster
Mittwoch, 29. März 2006, 16:30–19:30, P3
SFM-Investigations on cell motility — •C. Brunner1, M. Gögler1, A. Ehrlicher1, B. Kohlstrunk1, D. Knebel2, and J. Käs1 — 1Institute for Soft Matter Physics, University of Leipzig, Linnéstr. 5, 04103 Leipzig — 2JPK Instruments AG, Bouchéstr. 12, 12435 Berlin
A cells ability to move is essential for various functions in nature, such as morphogenesis, immune response, and the invasiveness of cancer. On the molecular level, actin polymerization and molecular motors, such as myosin, are involved in cell motility, but the mechanism as a whole is not very well understood. We used a scanning force microscopy (SFM) technique to directly measure the forward forces actively generated at the leading edge, the cell body, and in lamellar fragments of fish keratocytes. We glued polystyrene beads with 2-3 um radii to cantilever tips to provide a well-defined probe geometry and avoid puncturing the cell. The bead was positioned in front of a moving cell which pushed the bead out of its path and therefore bent the cantilever. The forward force was calculated using the detected vertical deflection of the cantilever in an elastic wedge model, which considers cellular deformation. To reveal more about the force generation machinery used during protrusion, we treated keratocytes with the drug cytochalasin D, which interrupts actin polymerization by capping the actin filaments. The cells velocity decreases depending on the drug concentration. Comparison of the protrusion forces with and without cytochalasin D reveals the importance of actin polymerization in keratocyte motility.