Actin-Myosin Viscoelastic Flow in the Keratocyte Lamellipod |
| |
Authors: | Boris Rubinstein Ken Jacobson Alex Mogilner |
| |
Institution: | † Stowers Institute for Medical Research, Kansas City, Missouri ‡ Ecole Polytechnique Federale de Lausanne, Laboratory of Cell Biophysics, Lausanne, Switzerland § Department of Cell and Developmental Biology, University of North Carolina School of Medicine, Chapel Hill, North Carolina ¶ Department of Neurobiology and Department of Mathematics, University of California, Davis, California |
| |
Abstract: | The lamellipod, the locomotory region of migratory cells, is shaped by the balance of protrusion and contraction. The latter is the result of myosin-generated centripetal flow of the viscoelastic actin network. Recently, quantitative flow data was obtained, yet there is no detailed theory explaining the flow in a realistic geometry. We introduce models of viscoelastic actin mechanics and myosin transport and solve the model equations numerically for the flat, fan-shaped lamellipodial domain of keratocytes. The solutions demonstrate that in the rapidly crawling cell, myosin concentrates at the rear boundary and pulls the actin network inward, so the centripetal actin flow is very slow at the front, and faster at the rear and at the sides. The computed flow and respective traction forces compare well with the experimental data. We also calculate the graded protrusion at the cell boundary necessary to maintain the cell shape and make a number of other testable predictions. We discuss model implications for the cell shape, speed, and bi-stability. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|