Contractility and retrograde flow in lamellipodium motion.
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.
Kruse
K
K
Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzerstr. 38, 01187 Dresden, Germany.
Joanny
J F
JF
Jülicher
F
F
Prost
J
J
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
D000199:Actins; D005782:Gels; D020409:Molecular Motor Proteins; D009218:Myosins