ActiveActinMembraneFlows

The surface of eukaryotic cells comprises a fluid lipid membrane densely populated with proteins. This membrane exhibits dynamic lipid reorganization and flow, processes known to be modulated by the network of actin filaments, called the actin cortex, which is physically coupled to the membrane. Class I myosin motors (myo1) act as dynamic linkers, coupling the membrane to the actin cortex. Myo1 plays a key role in various cellular processes involving dynamic reorganization of both actin and the membrane. Additionally, myo1 cyclically generates mechanical forces at the actin-membrane interface. However, the precise mechanical impacts of myo1’s action on the dynamic reorganization of the actin-membrane coupled composite remain elusive. In this project, we hypothesize that at the actin-membrane interface, mechanical forces generated by myo1 are transmitted to the membrane as well as the actin filaments, thereby inducing membrane flow and actin re-organization. Our project aims to elucidate how myo1 forces at the actin-membrane interface modulate and coordinate membrane flow and dynamic actin reorganization. Our team will use a synergistic approach, combining experimental and theoretical methods that will mutually inform each other. Our work provides a physics framework explaining how myo1 force dipoles affect both membrane and actin dynamics, and provide new insights into membrane hydrodynamics in non-equilibrium conditions.