Fig. 9
Impact of motor’s force-sensitivity on microtubule (MT) end-retention. a Force-unbinding (top) and force-velocity (bottom) characteristics used in model simulations, see Supplementary Note 1 for details. b Kaplan–Meier plots for the MT end-retention time. Experimental results are as in Fig. 2d but supplemented with measurements for Ndc80+Kinesin-1 at 2 mM adenosine triphosphate (ATP) (N = 7, n = 50) and 20 µM ATP (N = 2, n = 25). Theoretical plot is based on n = 32 simulations for each condition modeled using characteristics in a. c MT end-retention time vs. preceding gliding velocity for individual MTs in experiments with stabilized MTs. Data are based on N = 5, n = 76 for Ndc80+CENP-E; N = 7, n = 50 for Ndc80+Kinesin-1 (2 mM ATP); N = 2, n = 24 for Ndc80+Kinesin-1 in low ATP (20 µM ATP). d Kaplan–Meier plots calculated for molecular patches containing Ndc80 molecules and motor molecules with different force-dependent characteristics. Predictions for Ndc80+CENP-E and Ndc80+Kinesin-1 are the same as in b. Prediction for Kinesin* was calculated using force-dependent unbinding rate of CENP-E and the force-velocity function of Kinesin-1. Prediction for Kinesin** was calculated using the force-dependent unbinding rate of Kinesin-1 and the force-velocity function of CENP-E. e Average duration of MT end-retention vs. average gliding velocity in MT wall-to-end transition assay using CENP-E motor and indicated MT-associated proteins (MAPs). Duration of MT end-attachment is represented by the half-life of an exponential fit to the corresponding survival probability curve in Fig. 5c. Horizontal error bars are same as for MT end-retention time in Fig. 5b. Black line is the linear fit to all points. Pearson's correlation analysis gives R2 = 0.91 with 95% confidence, and hence the anti-correlation with gliding velocity is significant
