Genome-wide CRISPR screening reveals synthetic growth defects between the catalytic subunit of PP6 and the kinetochore protein NDC80. (A) A schematic depicting the role of TPX2 in stabilization of the active pool of Aurora A at the mitotic spindle. Aurora A switches between inactive unphosphorylated (T-form) and active phosphorylated (P-form) conformations. PP6 dephosphorylates the Aurora A–TPX2 complex and promotes Aurora A inactivation. Removal of PP6 thus results in amplified Aurora A activity. (B) A cartoon outlining how the enlarged spindles in PPP6C KO cells fail to maintain the compact array of chromosomes seen in parental cells during metaphase and anaphase. Escaped chromosomes in PPP6C KO cells go on to form micronuclei and cause other nuclear shape defects. (C) Pooled genome-wide CRISPR screens were performed in parental and PPP6C KO eHAP cells. Data from two independent screens were combined and analyzed using Fisher’s method to calculate Fisher’s combined P value (FCP). Significance (−log₁₀FCP) is plotted against the LFC in PPP6C KO compared with the parental cells. Significantly positively (orange) and negatively (blue) selected genes, P < 0.01 in both screens with mean LFC < 0.25 or >0.25 are highlighted on the plot.