ABSTRACT
Numerous proteins experience and respond to mechanical forces as an integral part of their cellular functions, but measuring these forces remains a practical challenge. Here, we present a compact, 11 kDa molecular tension sensor termed STReTCh (Sensing Tension by Reactive Tag Characterization). Unlike existing genetically encoded tension sensors, STReTCh does not rely on experimentally demanding Förster resonance energy transfer (FRET)-based measurements and is compatible with typical fix-and-stain protocols. Using a magnetic tweezers assay, we calibrate the STReTCh module and show that it responds to physiologically relevant, piconewton forces. As proof-of-concept, we use an extracellular STReTCh-based sensor to visualize cell-generated forces at integrin-based adhesion complexes. In addition, we incorporate STReTCh into vinculin, a cytoskeletal adaptor protein, and show that STReTCh reports on forces transmitted between the cytoskeleton and cellular adhesion complexes. These data illustrate the utility of STReTCh as a broadly applicable tool for the measurement molecular-scale forces in biological systems.
Competing Interest Statement
The authors have declared no competing interest.
