Hydrodynamic narrowing of tubes extruded from cells.
We discuss the pulling force f required to extrude a lipid tube from a living cell as a function of the extrusion velocity L. The main feature is membrane friction on the cytoskeleton. As recently observed for neutrophils, the tether force exhibits a "shear thinning" response over a large range of pulling velocities, which was previously interpreted by assuming viscoelastic flows of the sliding membrane. Here, we propose an alternative explanation based on purely Newtonian flow: The diameter of the tether decreases concomitantly with the increase of the membrane tension in the lipid tube. The pulling force is found to vary as L(1/3), which is consistent with reported experimental data for various types of cells.
Brochard-Wyart
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F
Laboratoire Physicochimie Curie, Institut Curie/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 168, 11, rue Pierre et Marie Curie, 75231 Paris Cedex 5, France. francoise.brochard-wyart@curie.fr
Borghi
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N
Cuvelier
D
D
Nassoy
P
P