This proposal will develop novel optical methods for visualizing mechanical stresses in live cells. They will study the mechanics at the subcellular level to understand transduction of mechanical stresses and the roles of key proteins in both focal adhesion and the cell cortex.
The key technical advance this project will pursue is to incorporate FRET (Forster resonance energy transfer)-based tension sensors into the current quantitative phase imaging platform. Tension sensors were developed by incorporating two fluorophores into load-bearing proteins. Traditionally dynamic loading has required indirect measures and complex devices. The proposed platform will be able to directly visualize cell stresses and to do so without mechanically displacing the cell. Further technical advances will develop FRET sensors for a load-bearing protein in the cell cortex to enable simple, reproducible loading of cells while preserving imaging capabilities.