Mechanics of the cellular actin cortex: from signalling to shape change

TL;DR

This paper reviews how the cellular actin cortex's composition, structure, and dynamics influence its mechanical properties and shape-changing functions during processes like mitosis.

Contribution

It provides a comprehensive overview of the mechanisms linking cortex composition and dynamics to cell shape regulation, highlighting recent insights.

Findings

Cortex composition and dynamics critically determine mechanical properties.

Regulation of cortex mechanics drives cell shape changes during mitosis.

The actin cortex enables cells to resist stresses and exert forces on neighbors.

Abstract

The actin cortex is a thin layer of actin, myosin, and actin binding proteins that underlies the membrane of most animal cells. It is highly dynamic and can undergo remodelling on time-scales of tens of seconds thanks to protein turnover and myosin-mediated contractions. The cortex enables cells to resist external mechanical stresses, controls cell shape, and allows cells to exert forces on their neighbours. Thus, its mechanical properties are key to its physiological function. Here, we give an overview of how cortex composition, structure, and dynamics control cortex mechanics and cell shape. We use mitosis as an example to illustrate how global and local regulation of cortex mechanics give rise to a complex series of cell shape changes.