Tension of 2 piconewtons or less decreased the rate of myosin I detachment from actin by >75-fold, transitioning it from a low (<0.2) to a high (>0.9) duty-ratio motor.
Effect estimate: >75-fold decrease
The ability to sense molecular tension is crucial for a wide array of cellular processes, including the detection of auditory stimuli, control of cell shape, and internalization and transport of membranes. We show that myosin I, a motor protein that has been implicated in powering key steps in these processes, dramatically alters its motile properties in response to tension. We measured the displacement generated by single myosin I molecules, and we determined the actin-attachment kinetics with varying tensions using an optical trap. The rate of myosin I detachment from actin decreases >75-fold under tension of 2 piconewtons or less, resulting in myosin I transitioning from a low (0.9) duty-ratio motor. This impressive tension sensitivity supports a role for myosin I as a molecular force sensor.
Laakso et al. (Thu,) reported a other. Tension (≤2 piconewtons) vs. Varying tensions was evaluated on Rate of myosin I detachment from actin and duty-ratio (>75-fold decrease). Tension of 2 piconewtons or less decreased the rate of myosin I detachment from actin by >75-fold, transitioning it from a low (<0.2) to a high (>0.9) duty-ratio motor.