Defining Single Molecular Forces Required to Activate Integrin and Notch Signaling

Sensing Tension Many cellular processes are regulated by mechanical signals. Single-molecule force spectroscopy has been used to probe molecular unfolding or unbinding; however, measuring the single-molecule forces required to activate signaling remains a challenge. Wang and Ha (p. 991 ) describe a “Tension Gauge Tether” approach to measure the force applied on a single receptor ligand bond. By using tethers with a range of tension tolerances and monitoring activation, the force required to activate signaling could be measured.