Figure 2.

Recruitment of BH3-only or p53 proteins to mitochondria following DNA damage is blocked by phosphatase inhibition. Cell fractions enriched in mitochondria were isolated from either HT1080 (A) or A549 (B) cells following a 4 hr incubation with CPT and probed for levels of the BH3-only proteins tBid or Bim. Pre-treatment of the cells with the protein tyrosine phosphatase (PTP) inhibitor sodium stibogluconate (SS, 100 µM) blocked the recruitment of tBid, Bim or p53 to mitochondria after DNA damage. Cox IV acted as a loading control.