XTcf-3 Transcription Factor Mediates Beta-Catenin-Induced Axis Formation in Xenopus Embryos

Cell. 1996 Aug 9;86(3):391-9. doi: 10.1016/s0092-8674(00)80112-9.

Abstract

XTcf-3 is a maternally expressed Xenopus homolog of the mammalian HMG box factors Tcf-1 and Lef-1. The N-terminus of XTcf-3 binds to beta-catenin. Microinjection of XTcf-3 mRNA in embryos results in nuclear translocation of beta-catenin. The beta-catenin-XTcf-3 complex activates transcription in a transient reporter gene assay, while XTcf-3 by itself is silent. N-terminal deletion of XTcf-3 (delta N) abrogates the interaction with beta-catenin, as well as the consequent transcription activation. This dominant-negative delta N mutant suppresses the induction of axis duplication by microinjected beta-catenin. It also suppresses endogenous axis specification upon injection into the dorsal blastomeres of a 4-cell-stage embryo. We propose that signaling by beta-catenin involves complex formation with XTcf-3, followed by nuclear translocation and activation of specific XTcf-3 target genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cytoskeletal Proteins / physiology*
  • DNA, Complementary
  • Embryonic Induction
  • Gene Expression Regulation, Developmental*
  • HMGB Proteins*
  • Molecular Sequence Data
  • Morphogenesis / genetics
  • Morphogenesis / physiology
  • Mutagenesis, Site-Directed
  • Restriction Mapping
  • TCF Transcription Factors
  • Trans-Activators*
  • Transcription Factor 3
  • Transcription Factor 7-Like 1 Protein
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Xenopus
  • Xenopus Proteins
  • beta Catenin

Substances

  • CTNNB1 protein, Xenopus
  • Cytoskeletal Proteins
  • DNA, Complementary
  • HMGB Proteins
  • TCF Transcription Factors
  • Tcf3 protein, Xenopus
  • Trans-Activators
  • Transcription Factor 3
  • Transcription Factor 7-Like 1 Protein
  • Transcription Factors
  • Xenopus Proteins
  • beta Catenin

Associated data

  • GENBANK/X99308
  • GENBANK/X99309
  • GENBANK/X99310
  • GENBANK/X99311