Big Question: Understanding how mechanical stress organizes actin cytoskeletal architecture

Principal Investigator: David Kovar, Molecular Genetics and Cell Biology

Funding Type: Seed

Big Idea: Cells produce and experience mechanical forces during fundamental processes such as division and motility. These forces are produced primarily by biopolymer networks of actin cytoskeleton filaments (Factin) that are constricted by molecular motors called myosin. Different contractile F-actin networks are assembled through the coordinated action of biochemically diverse actin-binding proteins (ABPs) that collectively regulate actin filament architecture and dynamics. The effect of ABPs on F-actin network organization and dynamics has been extensively studied over many years. However, far less is known about how mechanical forces applied to actin filaments affects ABP recruitment and activity. We hypothesize that forces applied to actin filaments significantly modifies the binding affinity and activity of a subset of ABPs, thereby regulating their recruitment to specific networks. This big idea has not been thoroughly investigated, principally due to technical difficulties of evaluating the effect on ABPs of applying forces to actin filaments. We are taking advantage of our expertise in purification of fluorescently labeled ABPs and single molecule microscopy imaging to build in vitro reconstitution platforms to systematically survey ABPs for differences in their ability to associate with and influence actin filaments in the absence and presence of mechanical stress.