Disrupting both microtubule-binding and PP1-docking activities of KNL-1 has an additive phenotype. (A) A still image of a living one-cell metaphase embryo from a strain expressing a 4A;RRASA KNL-1 mutant; endogenous KNL-1 was depleted. Bar, 2 µm. (B and C) Spindle pole separation kinetics for the indicated conditions. WT and single mutant traces (4A and RRASA) are reproduced from Figs. 2 D and 6 B. Error bars represent the SEM with a 95% confidence interval. Anaphase onset times are marked on the x axis. (D) Timing of anaphase onset in the first embryonic division for the indicated conditions. The gray dashed line is drawn as in Fig. 2 E. For statistical analysis, see Table S1. WT and single-mutant timing data are reproduced from Figs. 2 E and 6 E. Error bars represent the SEM with a 95% confidence interval. (E) Mean duration of AB cell mitosis for the indicated conditions. Dashed lines are drawn as in Fig. 3 B; WT and single-mutant data are from Figs. 3 B and 6 H. For statistical analysis, see Table S2. Error bars represent the SEM with a 95% confidence interval. (F) A schematic summarizing the conclusion that the microtubule-binding activity located in the N terminus of KNL-1 participates in checkpoint silencing.