Active-microrheology of actin–intermediate filaments composite networks

The cytoskeleton--a highly dynamic and complex network of biopolymers comprising actin, microtubules, and intermediate filaments--plays a vital role in several cellular processes ranging from the stability and rigidity of biological cells to cell motility and shape change. Central to this multifunctionality is the inherent stiffness of each filament and the myriad binding proteins that serve to crosslink, bundle, assemble, and disassemble these filaments. Exploring the mechanics and dynamics of in vitro reconstituted networks consisting of only one of these cytoskeletal components has been the subject of extensive experimental and theoretical work. However, the role each cytoskeletal component plays in their composite networks' mechanical properties and structural dynamics is yet to be well understood. In this talk, I will present our recent work on the microscale mechanics of in vitro reconstituted filamentous actin (F-actin)--vimentin intermediate filaments (VIFs) composite networks using active microrheology coupled with microfluidics techniques. Our measurements shed new light on how VIFs and F-actin work synergistically during the various cellular processes.