Figure 6.

The main apoptotic degradation product of BLM shows impaired topoisomerase IIIα interaction. Nuclear extracts were made from control HL-60 cells or from cells which had been treated with 68 µM etoposide for 5 h. Nuclear extracts (150 µg) were incubated in the presence of 50 µg anti-C-terminal BLM antibody for 1 h at 4°C and immunoprecipitated using Dynabeads coupled to anti-rabbit antibodies. Control experiments were carried out using uncoupled beads. The western blot was probed with anti-C-terminal-BLM and anti-topoisomerase IIIα antibodies as indicated in the figure.