Figure 1.

A, Position frequency matrix of the T‐cell factor (TCF) motif was obtained from the JASPAR database (http://jaspar.genereg.net). B, TOPFlash consists of tandemly repeated TCF motifs (Wnt response elements [WREs]) upstream of a minimal promoter that drives luciferase gene expression. FOPFlash has mutated motifs (mWREs) and is used to normalize the TOPFlash activity. HAL reporter was developed as a luciferase reporter driven by 8 copies of the promoter of histidine ammonia‐lyase (HAL). Transcription factor (TF) that regulates the activity of HAL promoter is under investigation. C, These reporter plasmids were designed for monitoring the activity of Wnt/β‐catenin pathway in cultured cells. When the pathway is inhibited, TOPFlash and HAL reporter activities are decreased and increased, respectively