Berlin 2005 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 100: Poster Session I
AKB 100.18: Poster
Samstag, 5. März 2005, 16:45–18:45, Poster TU D
Protrusion forces driving rapidly translocating cells — •Michael Gögler1, Claudia Brunner1, Allen Ehrlicher1, Bernd Kohlstrunk1, Detlev Knebel2, and Josef Käs1 — 1Institute for Soft Matter Physics, University of Leipzig, Linnéstrasse 5, 04103 Leipzig — 2JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin
Cell motility is a fundamental process of many phenomena in nature, such as immune response, wound healing, and metastasis. Mechanisms of force generation for cell migration have been described in various hypotheses requiring actin polymerization and/or molecular motors, but quantitative force measurements to date have focused on traction forces. Here we present a direct measurement of the forward force generated at the leading edge of the lamellipodium and at the cell body of a translocating fish keratocyte. To elucidate the sub-cellular force generation machinery, we additionally determined the forward force of locomoting lamellar fragments, which lack their nuclei but remain motile. We positioned an elastic spring, the cantilever of a scanning force microscope (SFM), in front of a moving cell, which pushes this spring out of the way. The forward force was calculated using the detected vertical deflection of the cantilever in an elastic wedge model, which considers cellular deformation. Our measurements of the propulsive forces, which are in the lower nN range and agree with expectations, will provide quantitative insight into how a polymeric network of active and passive molecular components act in concert as an active locomoting machine.