Actin-myosin viscoelastic flow in the keratocyte lamellipod.
Biophys J
; 97(7): 1853-63, 2009 Oct 07.
Article
em En
| MEDLINE
| ID: mdl-19804715
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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Actinas
/
Miosinas
/
Elasticidade
/
Fibroblastos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Biophys J
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos