FIGURE 5:

MCAK/Kif2C levels must be tuned to suppress chromosome instability. (A) A field of CRISPR cells expressing endogenous levels of GFP-FKPB-MCAK/Kif2C (green) and labeled for tubulin (red) and DNA (blue). (A′) DNA only showing late anaphase cell (open arrow). (B) A field of CRISPR cells expressing endogenous levels of GFP-FKPB-MCAK/Kif2C (green) and labeled for tubulin (red) and DNA (blue) in 200 nM rapamycin. (B′) DNA only showing a telophase cell with lagging chromosomes (arrow). (C) Relocalization of endogenous GFP-FKBP-MCAK increases the proportion of lagging chromosomes in GFP-transfected control cells. This can be rescued by cotransfection of GFP-MCAK/Kif2C, but this operation increases lagging chromosomes when performed in a background of properly localized endogenous protein. The inactive R260H mutant increases chromosome instability regardless of the status of endogenous protein. Each point represents measurements for 25 fields of cells. Medians and interquartile range (red bars) are plotted. Significance is calculated from the median of the points using the one-sample t and Wilcoxon’s tests of significant difference from the baseline level of chromosome instability (CIN); *p < 0.05.