Lef/Tcf‐dependent Wnt/β‐catenin signaling during Xenopus axis specification

FEBS Letters

Lin, Gu Fa²  Ding, Xiaoyan²  Rupp, Ralph A.W¹  Geng, Xin²  Xiao, Lei¹  Hu, Ruiying²  Wang, Jin Hu² 

[1] Department of Molecular Biology, Adolf-Butenandt Institute, Munich University, Schillerstr. 44, D-80336 Munich, Germany;Laboratory of Molecular and Cell Biology, Laboratory of Stem Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Yue-yang Road 320, 200031 Shanghai, PR China

关键词: Axis specification;    Wnt;    β-Catenin;    Lef-1;    Tcf;    Restriction enzyme-mediated integration transgenesis;    Xenopus;    GFP;    green fluorescent protein;    Luc;    luciferase;    MHB;    midbrain–hindbrain boundary;    GSK-3β;    glycogen synthase kinase 3β;    REMI;    restriction enzyme-mediated integration;    MBT;    mid-blastula transition;    NSE;    non-specific expression;    NE;    no expression;    PE;    patched expression;   

DOI  :  10.1016/S0014-5793(03)00639-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Though the Wnt/β-catenin signaling pathway is known to play key roles during Xenopus axis specification, whether it signals exclusively through Lef/Tcf transcription factors in this process remains unclear. To investigate this issue, we generated transgenic frog embryos expressing green fluorescent protein (GFP) driven by a Lef/Tcf-dependent and Wnt/β-catenin-responsive promoter. This promoter is highly sensitive and even detects maternal β-catenin activity prior to the large-scale transcription of zygotic genes. Unexpectedly, GFP expression was observed only in some, but not all, known Wnt/β-catenin-positive territories in Xenopus early development. Furthermore, ubiquitous expression of dominant Lef-1 protein variants from transgenes revealed that zygotic Lef/Tcf activity is required for the ventroposterior development of Xenopus embryos. In summary, our results suggest that endogenous Wnt/β-catenin activity does not result in obligatory Lef/Tcf-dependent gene activation, and that the ventroposteriorizing activity of zygotic Wnt-8 signaling is mediated by Lef/Tcf proteins.

【 授权许可】

Unknown