a. When pulled towards the minus-end, dynein exhibits a slip bond behavior with an MT, in which the release rate increases exponentially by assisting force (black dashed curve). In the hindering direction, possible force-detachment kinetics of slip, slip-ideal, ideal and catch bond behavior are shown for comparison (solid curves). b. Cumulative distributions of dynein dwell time on an MT under a given force were fit to a double exponential decay (red curves) to calculate fast (k1) and slow (k2) release rates from MT. n = 504 for 1 pN and 512 for −1 pN. c. k1 of dynein from MT (mean ± s.e.m.; n 270, 243, 479, 407, 385, 354, 487, 461, 380, 260, 208, 325, 137, 325 from left to right). This rate likely represents a weak interaction between dynein and tubulin. Similar to k2 (Fig. 1c), k1 increases with force in both directions. d. Comparison of the single and double exponential fit to example cumulative distributions of dynein dwell time. p values are calculated using F-test.