New proposed mechanism of actin-polymerization-driven motility.
We present the first numerical simulation of actin-driven propulsion by elastic filaments. Specifically, we use a Brownian dynamics formulation of the dendritic nucleation model of actin-driven propulsion. We show that the model leads to a self-assembled network that exerts forces on a disk and pushes it with an average speed. This simulation approach is the first to observe a speed that varies nonmonotonically with the concentration of branching proteins (Arp2/3), capping protein, and depolymerization rate, in accord with experimental observations. Our results suggest a new interpretation of the origin of motility. When we estimate the speed that this mechanism would produce in a system with realistic rate constants and concentrations as well as fluid flow, we obtain a value that is within an order-of-magnitude of the polymerization speed deduced from experiments.
Lee
Kun-Chun
KC
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Liu
Andrea J
AJ
D000199:Actins / Q000737:chemistry* / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D003198:Computer Simulation; D019281:Dimerization; D008954:Models, Biological; D008956:Models, Chemical; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000502:physiology*
D000199:Actins; D020409:Molecular Motor Proteins