FIGURE 1.

SRPK2 is a substrate of caspases. A, SRPK2 is cleaved in the cell-free apoptotic solution in caspase-3/7-dependent manner. The active or inactive cell-free apoptotic S-100 was preincubated with or without 10 μm AC-DEVD-CHO for 30 min, followed by addition of [³⁵S]methionine-labeled SRPK2. The reaction mixture was incubated at 37 °C for another 2 h, resolved in SDS-PAGE, and visualized by autography. B, VP16 treatment induces apoptotic SRPK2 cleavage in cells. HEK293 cells were transfected with Myc-tagged SRPK2, pretreated with 30 μm AC-DEVD-CHO or z-VAD-FMK for 0.5 h, and then treated with or without 50 μm VP16 for another 16 h. The cell lysates were analyzed by Western blot with the anti-Myc antibody.