Flow & Transport in Biological Interfaces

Many cellular processes involve the transport of proteins and biopolymers on curved fluid-like interfaces. One example is the continuous reorganization of the cell cortex made of the dynamic network of actin filaments, which determines the cell’s mechanical integrity and drives cell division. Another example is the transport and organization of rodlike proteins that preferentially bind to areas of specific curvatures, such as septin oligomers and BAR domains. The the curved closed geometry of biological interfaces introduces novel features to momentum and mass transport at the interface, which makes it distinct from 3D and 2D planar flows. These geometric features are determined themselves by the the coupling between the interfacial stresses and the viscoelastic properties of the interface.

Thus far we have studied the dynamics of a single filament and a collection of them on planar and spherical lipid membranes, using slender-body theory and continuum active liquid crystal theories. We have also used MD simulations to study the binding of helical amphipathic domains to lipid bilayers. These studies are all motivated by our research on multiscale assembly of septin cytoskeletal proteins on spherical membranes.