FIG. 1.

Notch potentiates LEF-1 activity. (A) Schematic representations of reporters used to assay LEF-1 activity. Binding sites for LEF-1 are shown as gray (consensus) or black (mutant) ovals. (B) Effects of LEF-1, β-catenin, and NICD on 7xLEF-luc and LEF-OT in Neuro-2A cells. Relative luciferase values for reporters containing seven LEF-1 binding sites (7xLEF-luc; gray bars) or no LEF-1 binding sites (fos-luc; black bars) are shown in the left panel. Values for reporters having three consensus LEF-1 binding sites (LEF-OT; gray bars) or three mutant LEF-1 binding sites (LEF-OF; black bars) are shown in the right panel. Values for fold induction were determined relative to those obtained for each reporter in the absence of any expression plasmids. (C) Effects of LEF-1 and NICD on naturally occurring promoters. Transfections of Neuro-2A cells were carried out with reporters containing promoters from the WISP-1 (white bars), Cyclin D1 (striped bars), or Xtwn (black bars) genes. Expression plasmids that were cotransfected with each set of reporters are indicated. Values are given as fold induction relative to the reporter alone.