This Faculty Early Career Development (CAREER) Program grant will pioneer a new approach for understanding the effects of mechanical force on the dynamics of specific proteins in living cells. Disease is generally understood and treated through biochemical means; when we get sick, we typically get a pill. However, in addition to biochemical signals, cells are subject to a wide variety of mechanical cues. Inside living tissues, cells exist in a complex mechanical environment that is both a source of applied forces and a means of mechanical support. Alterations in the mechanical environment surrounding cells are potent regulators of many fundamental processes, including how cells grow, migrate, and develop into different tissue types. Understanding how cells sense, interpret, and respond to mechanical cues is currently limited by the inability to study the interplay between mechanical forces and biochemical signaling pathways at the molecular level in living cells. A greater understanding of this relationship will aid endeavors to develop therapies for diseases like cancer and atherosclerosis, where the mechanical environment is altered, as well as efforts to engineer replacement tissues for regenerative medicine.
An incomplete understanding of the processes cells use to detect mechanical cues, referred to as mechanotransduction, is preventing advancements in diverse fields, ranging from fundamental studies of the collective movements of cells during morphogenesis to applied research geared toward improving tissue engineering approaches by incorporating relevant mechanical stimuli. The sub-cellular structures that mechanically link the force-generating cytoskeleton to the extracellular environment, termed focal adhesions, are known to be innately sensitive to mechanical force and critically important in mechanotransduction. A key molecular process dictating these force-activated dynamics is the mechanical loading of vinculin, an adaptor protein found in focal adhesions. This research will create and utilize state of the art molecular tools and experimental approaches capable of elucidating the interdependence and dynamics of the molecular-scale mechanical and biochemical processes mediating mechanotransduction in living cells and tissues. Novel tools include genetically-encoded molecular tension sensors with rationally-designed biophysical properties and defined biochemical functions. Additionally, a simple, but novel, experimental procedure for directly measuring force-activated protein dynamics will be developed. These will be combined to test the hypothesis that distinct forms of mechanical stimulation are detected and integrated by the cell through alterations in the force-activated dynamics of vinculin.
