pubmed:abstractText |
The restricted expression of XTcf-4 in the anterior midbrain is regulated via an active wnt/beta-catenin pathway (Kunz et al.,2004, Dev Biol 273:390-401). The molecular mechanism of this autoregulatory loop, however, remained elusive. Here we show that the activity of a 1,775 bp promoter fragment containing a consensus Lef/Tcf binding site at position -1,437 to -1,428 is upregulated by activating transcription factors of the Lef/Tcf family. Furthermore, chromatin immunoprecipitation revealed that endogenous beta-catenin is bound to the Lef/Tcf site on the promoter. Thus, regulation of XTcf-4 by canonical wnt-signaling is directly controlled by binding to and activating a consensus Lef/Tcf binding site within its own promoter.
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