FIG. 7.

Retrovirally expressed NICD stimulates LEF-1 activity. (A) NIH 3T3 cells transduced with either the MIGR (black bars) or MIGR-NICD (gray bars) retroviruses and then transfected with LEF-OF or LEF-OT reporters and a LEF-1 expression vector. Results for each transduced cell population are shown as fold induction relative to the LEF-OF plus LEF-1. (B) Tamoxifen-responsive NICD stimulates LEF-1 activity. NIH 3T3 cells were transduced with retroviruses expressing either the parental ER element (ER cells) or NICD fused to the estrogen receptor element (NICD-ER cells). LEF-1 activity was assayed in the absence (black bars) or presence (gray bars) of 25 nM tamoxifen, following the transfection of ER and NICD-ER cells with the LEF-OF or LEF-OT reporters and a LEF-1 expression vector. Results are shown as fold induction relative to LEF-OF and LEF-1 with no tamoxifen.