Ezrin, radixin, and moesin are dispensable for macrophage migration and cellular cortex mechanics.

The cellular cortex provides crucial mechanical support and plays critical roles during cell division and migration. The proteins of the ERM family, comprised of ezrin, radixin, and moesin, are central to these processes by linking the plasma membrane to the actin cytoskeleton. To investigate the contributions of the ERM proteins to leukocyte migration, we generated single and triple ERM knockout macrophages.

The third dimension of the actin cortex.

The actin cortex, commonly described as a thin 2-dimensional layer of actin filaments beneath the plasma membrane, is beginning to be recognized as part of a more dynamic and three-dimensional composite material. In this review, we focus on the elements that contribute to the three-dimensional architecture of the actin cortex. We also argue that actin-rich structures such as filopodia and stress fibers can be viewed as specialized integral parts of the 3D actin cortex.

A Magnetic Pincher for the Dynamic Measurement of the Actin Cortex Thickness in Live Cells.

The actin cortex is an essential element of the cytoskeleton allowing cells to control and modify their shape. It is involved in cell division and migration. However, probing precisely the physical properties of the actin cortex has proved to be challenging: it is a thin and dynamic material, and its location in the cell-directly under the plasma membrane-makes it difficult to study with standard light microscopy and cell mechanics techniques.

Asymmetric bistability of chiral particle orientation in viscous shear flows.

The migration of helical particles in viscous shear flows plays a crucial role in chiral particle sorting. Attaching a nonchiral head to a helical particle leads to a rheotactic torque inducing particle reorientation. This phenomenon is responsible for bacterial rheotaxis observed for flagellated bacteria as in shear flows.

Dynamics of flexible filaments in oscillatory shear flows.

The fluid-structure interactions between flexible fibers and viscous flows play an essential role in various biological phenomena, medical problems, and industrial processes. Of particular interest is the case of particles freely transported in time-dependent flows. This work elucidates the dynamics and morphologies of actin filaments under oscillatory shear flows by combining microfluidic experiments, numerical simulations, and theoretical modeling.