Project Summary PI: Daniel Fletcher, Ph.D. NIH R01 application, PA-18-484 Project Title: Mechanical regulation of acting binding proteins Project Period: 07/01/2019 – 06/30/2024 The actin cytoskeleton consists of spatially organized structures of filaments that are architecturally distinct and formed from over 300 different actin-binding proteins. One of the key roles of actin networks in cells is to generate, transmit, and resist physical forces, but whether the forces carried by actin filaments influence the binding of actin-binding proteins is not well understood. This proposal will investigate the ability of tandem calponin-homology domains (CH1-CH2) to bind actin filaments in a tension-dependent manner, and it will explore the functional impact of tension-dependent binding through a set of in vitro experiments measuring the mechanical properties of actin gels with tension-dependent crosslinkers and live cells experiments quantifying the effect of tension-dependent signaling and cytoskeletal organization on crawling motility. The outcome of this work will be a new understanding of how force can organize actin networks and influence the function of both healthy and diseased cells.