FIGURE 1.

Protease-dependent generation of BMXΔN. A, schematic depiction of the generation of BMXΔN by either caspase cleavage after Asp-242 or as a ubiquitin fusion to generate BMXΔN with an N-terminal tryptophan. PH, pleckstrin homology domain. B, transient transfection with BMX-FLAG or Ub-BMXΔN-FLAG in PC3 cells. After transfection, the cells were treated with 10 nm docetaxel or left untreated before lysis and analysis by SDS-PAGE and Western blotting (WB) analysis with an anti-FLAG antibody. WB analysis reveals that docetaxel treatment results in cleavage of full-length BMX, which results in a cleaved product with electrophoretic mobility identical to that of BMXΔN. C, PC3 cells were transfected with plasmids to express full-length BMX (light gray bars), BMXΔN (dark gray bars), or a vector control (white bars). Cells were then treated with the indicated concentrations of docetaxel for 48 h and then assayed for viability using trypan blue staining. The data represent the average and S.D. (error bars) from three independent experiments, and p values were derived from paired two-tailed t tests. D, FACS analysis of docetaxel-treated PC3 cells. PC3 cells were transfected with the indicated expression plasmids and then left untreated or were treated with 10 nm docetaxel for 48 h. The percentage of cells that were only stained with annexin V (dark gray) or with both annexin V and propidium iodide (light gray) are shown. The data represent the average and S.D. from three independent experiments, and p values were derived from paired two-tailed t tests.