title: Contractility and retrograde flow in lamellipodium motion.
abstract: We present a phenomenological description of cell locomotion on a solid substrate. The material properties of the actin cytoskeleton in the lamellipodium are described by the constitutive equations of a viscous polar gel with intrinsic activity. The polymerization of the gel takes place in a localized region near the leading edge. Using a simple two-dimensional description, we calculate in the steady state the thickness profile of the lamellipodium which at the rear connects to the cell body; we also calculate the flow profiles and the forces exerted on the substrate. The cell velocity is estimated as a function of externally applied forces. Our description is consistent with experimentally observed properties of motile cells such as the existence of a retrograde flow in the lamellipodium and a dipolar force distribution exerted by the cell on the substrate.
authors.affiliation: Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzerstr. 38, 01187 Dresden, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kruse
authors.forename: J F
authors.initials: JF
authors.lastname: Joanny
authors.forename: F
authors.initials: F
authors.lastname: Jülicher
authors.forename: J
authors.initials: J
authors.lastname: Prost
mesh_terms: D000199:Actins; D000818:Animals; D016880:Anisotropy; D002465:Cell Movement; D002478:Cells, Cultured; D003599:Cytoskeleton; D005782:Gels; D008954:Models, Biological; D020409:Molecular Motor Proteins; D009038:Motion; D009218:Myosins; D011554:Pseudopodia
chemical_list: D000199:Actins; D005782:Gels; D020409:Molecular Motor Proteins; D009218:Myosins