...-helix (bHLH) domain of Ascl1, and DNA-binding assays demonstrated that this interaction interferes with the ability of Ascl1 to bind DNA. Finally, we modified a proximity ligation assay for tissue sections and found that Ascl1-Gsx2 interactions are enriched within LGE VZ progenitors, whereas Ascl1-Tcf3...

...Jackson A. Hoffman; Chun-I Wu; Bradley J. Merrill The core gene regulatory network (GRN) in embryonic stem cells (ESCs) integrates activities of the pro-self-renewal factors Oct4 (Pou5f1), Sox2 and Nanog with that of an inhibitor of self-renewal, Tcf7l1 (Tcf3). The inhibitor function of Tcf7l1...

... for Tcf1, Tcf4 and Lef1, the known embryonic functions for Tcf3 in mice, frogs and fish are consistent with β-catenin-independent repressor activity. In this study, we genetically define Tcf3–β-catenin functions in mice by generating a Tcf3 ΔN knock-in mutation that specifically ablates Tcf3–β-catenin...

... on its zinc-finger domains (ZF1-3) and the corresponding HMG DNA-binding domain of TCF3/4 factors. Our data rule out a model suggesting that xKaiso is a direct repressor of Wnt signalling target genes in early Xenopus development via binding to promoter-proximal CTGCNA sequences as part of a xTcf3...

...Suzanna L. Gribble; Hyung-Seok Kim; Jennifer Bonner; Xu Wang; Richard I. Dorsky The Lef/Tcf factor Tcf3 is expressed throughout the developing vertebrate central nervous system (CNS), but its function and transcriptional targets are uncharacterized. Tcf3 is thought to mediate canonical Wnt...

..., and cancer formation. Although much of the accumulated work on these proteins involves their ability to transactivate target genes when stimulated by β-catenin, Lef/Tcf proteins can repress target genes in the absence of stabilized β-catenin. By ablating Tcf3 function, we have uncovered an important...

... engineered mice harboring TOPGAL, a β-galactosidase gene under the control of a LEF/TCF and β-catenin inducible promoter. In mice, TOPGAL expression was directly stimulated by a stabilized form of β-catenin, but was also dependent upon LEF1/TCF3 in skin. During embryogenesis, TOPGAL activation occurred...

... interact, in vitro, with consensus LEF1/TCF3-binding sites found within the Xtwn promoter. Second, these binding sites were shown to be required for Wnt-mediated induction of a Xtwn reporter gene containing these sites. As LEF1/TCF3 family transcription factors have previously been shown to directly...