FIG. 5.

Transcriptional activation domain of Cdx1 activates the Cdx1 promoter. (A) The N-terminal domain of Cdx1 contains a transactivation function. P19 cells were transfected with a reporter vector containing GAL4 binding elements (pXPA17-5XUAS), alone or with the indicated GAL4 DNA binding domain-Cdx1 fusion. Luciferase activity was measured 48 h posttransfection and expressed as induction relative to activity with the reporter vector alone. (B) The N-terminal domain of Cdx1 can activate transcription from the Cdx1 promoter when fused to the LEF1 HMG box. P19 cells were transfected with the 180-bp proximal Cdx1 reporter construct (WT) or an identical construct lacking the LEF/TCF response elements (MUT). Transfections were performed either with the reporter vector alone or with the indicated fusion construct. Luciferase activity and results were determined as above.