The actin cortex as an active wetting layer

TL;DR

This paper models the actin cortex as an active wetting layer using active gel theory, revealing how actin dynamics determine the layer's thickness and edge properties in animal cells.

Contribution

It introduces a theoretical framework describing the actin cortex as a non-equilibrium wetting film, linking actin polymerization and depolymerization to layer structure.

Findings

Layer thickness depends on polymerization and depolymerization rates.

Actin density remains approximately constant within the layer.

The model predicts a sharp edge where actin density drops to zero.

Abstract

Using active gel theory we study theoretically the properties of the cortical actin layer of animal cells. The cortical layer is described as a non-equilibrium wetting film on the cell membrane. The actin density is approximately constant in the layer and jumps to zero at its edge. The layer thickness is determined by the ratio of the polymerization velocity and the depolymerization rate of actin.