FIGURE 9:
DTX1 depletion promotes signaling of activated Notch forms. tTA HeLa cells were treated with control siRNA (A and C) or siRNA directed against DTX1 (B and D), infected with 25 μl/ml pTREL-CD8-NΔE (see Figure 8), treated with either DMSO (A and B) or CE (C and D). Cells were then fixed and probed with antibody against NICD. Boxed regions indicates area of the plasma membrane at higher magnification. Scale bar: 20 μm. (E) tTA HeLa cells treated with control or DTX1 siRNA were infected with increasing concentrations of adenovirus encoding the indicated Notch chimera, and signaling was measured by luciferase assay. Each bar within a group (left to right) corresponds to increasing adenovirus concentrations (0, 1, 5, 10, and 25 μl/ml) documented in Figure 8. * and ** indicate p values by t test: *, p < 0.05; **, p < 0.005.