Cardiomyocyte or HeLa cells were seeded in 6-well plates (1x106 cells per well), and incubated with T. cruzi (cell/parasite ratio of 1:5) in presence or absence of 1 ?M PJ34 for 24 h. Cells were suspended in lysis buffer (50 mM Tris pH 7.5, 150 mM NaCl, 1 mM EDTA, 1 mM EGTA, 1% Nonidet P-40, 2.5 mM KH2PO4, and 1 mM Na3VO4), and incubated on ice for 30 min. Cell lysates were centrifuged at 12,000 g at 4°C for 15 min and the resultant supernatants were stored at ?80°C. For fractionation, cells (7?106/ml) were incubated on ice for 30 minutes in buffer A (10 mM HEPES, pH 7.9, 10 mM NaCl, 0.1 mM EDTA, 0.1 mM EGTA, 1 mM DTT, 1 mM PMSF) containing 0.625% NP-40 and 1% protease inhibitor cocktail. Cell lysates were centrifuged at 4°C at 10,000 g for 1 min and supernatants were stored as a cytosolic fraction. Pellets were washed with buffer A containing 1.7 M sucrose, re-suspended in buffer B (20 mM HEPES pH 7.9, 0.4 M NaCl, 1 mM EDTA, 1 mM EGTA, 1 mM DTT, and 1 mM PMSF), and centrifuged at 4°C at 13,000 g for 5 minutes. The resultant supernatants were stored at ?80°C as nuclear extracts. Mitochondria were isolated from cells as above.