Fig. 6.

The C-terminal portion of SidF is important for its activity. (A and B) Interactions between Bcl-rambo and SidF mutants. 293T cells were transfected with combinations of plasmids expressing Flag-Bcl-rambo and individual mutants. Precipitates were prepared with anti-SidF antibody (A) or with anti-Bcl-rambo antibody (B). The presence of target proteins was detected with appropriate antibodies. In each case, 5% of the lysate used for coimmunoprecipitation was probed for levels of input proteins in total cell lysates. (C) Inhibition of Bcl-rambo activity by SidF and its derivatives. MCF-7 cells were transfected to express SidF and its derivatives along with Bcl-rambo (shaded bars) or the vector (open bars). Twenty-four hours after transfection, cells were fixed and stained with Hoechst 33342 and apoptotic rates were scored. Data shown are from three independent experiments, with standard deviations. ∗, P < 0.05; ∗∗, P < 0.01.