Expression of TDP2, but not ZNF451, correlates with impaired localization of Mre11 and ATM to the bridge DNA next to the midbody. (A) Percentage of broken DNA bridges in BE cells treated with 10 μM MG132 or 10 μM MLN7243 for 4 h, in the absence (control) or presence of Top2α siRNA. (B–D) Localization and mean intensity of Top2α at the bridge DNA next to the midbody. Mean ± SD from n cells. Values in MG132 were set to 1. (E–L) Localization and mean intensity of Mre11 or ATM at the bridge DNA next to the midbody in cells expressing GFP, ZNF451:GFP, or TDP2:GFP. Mean ± SD from n cells. Values in GFP were set to 1. ***, P < 0.001 (ANOVA and Student’s t test). (M) Percentage of broken DNA bridges in cells expressing GFP or ZNF451:GFP. Mean ± SD from three independent experiments (n > 120). Broken chromatin bridges are indicated by dotted arrows. Arrowheads indicate DNA knots. Midbodies (boxed areas) were reexported and are shown at higher magnification. Numbers below/next to each bar indicate n. Scale bars, 5 μm.