Fig. 3.

p8 and ProTα are required for caspase 9 activation in staurosporine-treated cells. Cells transfected with control siRNA or with siRNAs for p8 and ProTα, alone or together were plated at 2.5 × 10⁴ cells per well in 48-well plates. After 24 h, cells were incubated 4 h with 1 μM staurosporine. Caspase 9 activity was measured as described in Methods. Results are expressed as in Fig. 2. Caspase 9 activity was enhanced upon p8 or ProTα knockdown.