A minimal TOG2 domain construct is sufficient to induce stabilized microtubule depolymerization. (A) Domain structures of human CLASP family members and an EGFP-tagged TOG2 domain from CLASP2α. (B) Representative kymographs of GMPCPP-stabilized microtubules incubated with storage buffer, 200 nM CLASP1, 200 nM CLASP2α, 200 nM CLASP2γ, or 200 nM EGFP-L-TOG2-S in the presence of 1 mM GTP. (C) Quantification of microtubule depolymerization rates for the conditions in B. The mean rates of microtubule depolymerization are: 0.19 ± 0.03 nm/s (SE; N = 221 microtubules) for the buffer control, 7.1 ± 0.8 nm/s (SE; N = 102 microtubules) for CLASP1, 3.2 ± 0.5 nm/s (SE; N = 70 microtubules) for CLASP2α, 2.4 ± 0.2 nm/s (SE; N = 100 microtubules) for CLASP2γ, and 2.0 ± 0.2 nm/s (SE; N = 86 microtubules) for L-TOG2-S. All data were obtained across at least three different experimental days, and individual data points from different experiments are plotted in different shades. The means for each experimental repeat are plotted as larger points in the same color. The squares indicate the average of the experimental means, and the vertical bars are the standard errors of the means. Statistical significance was determined using a one-way ANOVA followed by Tukey’s HSD test for multiple comparisons, and the corresponding P values are indicated on the graph.