Wnt target enhancer regulation by a CDX/TCF transcription factor collective and a novel DNA motif

Abstract Transcriptional regulation by Wnt signalling is primarily thought to be accomplished a complex of ?-catenin and TCF family transcription factors (TFs). Although numerous studies have suggested that additional TFs play roles in regulating target genes, their mechanisms action not been investigated detail. We characterised Wnt-responsive element (WRE) downstream the gene Axin2 found TCFs Caudal type homeobox (CDX) proteins were required for its activation. Using new separation-of-function mutant, we WRE activity requires formation TCF/CDX complex. Our systematic mutagenesis this enhancer identified other sequences essential activation signalling, including several copies novel CAG DNA motif. Computational experimental evidence indicates TCF/CDX/CAG mode prevalent multiple WREs. Put together, our results demonstrate nature cis- trans- interactions signal-dependent activity.