KIF15’s C-terminal tail contributes to spindle localization in the presence of KBP. (A) Metaphase cells arrested in MG132 transfected with GFP-tagged KIF15-FL or C-terminally truncated GFP-tagged KIF15-N700 with or without mCherry-tagged KBP (mCh-KBP). (B) Quantification of background subtracted spindle-to-cytoplasmic ratio of GFP in individual cells expressing GFP-KIF15-FL (left) and GFP-KIF15-N700 (middle). ****, P < 0.0001; *, P = 0.0387 by unpaired, two-tailed t test. Right: Quantification of background subtracted average fluorescence intensity of the indicated constructs; n.s., not significant with 95% confidence interval by one-way ANOVA with Tukey’s multiple comparisons test. Error bars represent SD. Data were obtained from three independent datasets with the following cell numbers: GFP-KIF15-FL (27), GFP-KIF15-FL + mCh-KBP (27), GFP-KIF15-N700 (36), and GFP-KIF15-N700 + mCh-KBP (38).