Survivin-ClpXP interaction.

(A) Heatmap of proteomics identification of mitochondrial proteins co-precipitated with an antibody to survivin (SVV) or control IgG from PC3 mitochondrial extracts. Two independent replicates per condition are shown. A fold enrichment in spectra counts (SVV/IgG) is shown. (B–D) Mitochondrial extracts from PC3 cells were immunoprecipitated (IP) with antibodies to survivin (SVV) (B), ClpP (C), ClpP or ClpX (D), or non-binding IgG and analyzed by western blotting. TCE, total cell extracts. MTE, mitochondrial extracts. CS, citrate synthase. (E) Submitochondrial fractions representative of outer membrane (OM), inter-membrane space (IMS), inner membrane (IM), or matrix were isolated from PC3 cells and analyzed by western blotting. (F) PC3 cells were treated with vehicle (Veh) or small molecule survivin (SVV) suppressant YM155 and analyzed by western blotting. (G) PC3 cells in normoxia (N) or hypoxia (H) were transfected with control non-targeting siRNA (Ctrl) or survivin (SVV)-directed siRNA and analyzed by western blotting. (H) MCF-7 cells were transfected with vector or mitochondrial-targeted (mt) survivin (SVV) cDNA and analyzed by western blotting. Expo, exposure.