Regulation of Wnt signaling by Sox proteins: XSox17α/β and XSox3 physically interact with β-catenin

Aaron M. Zorn*, Grant D. Barish, Bart O. Williams, Paul Lavender, Michael W. Klymkowsky, Harold E. Varmus

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

297 Scopus citations


Using a functional screen in Xenopus embryos, we identified a novel function for the HMG box protein XSox17β. Ectopic expression of XSox17β ventralizes embryos by inhibiting the Wnt pathway downstream of β-catenin but upstream of the Wnt-responsive gene Siamois. XSox17β also represses transactivation of a TCF/LEF-dependent reporter construct by Wnt and β-catenin. In animal cap experiments, it both activates transcription of endodermal genes and represses β-catenin-stimulated expression of dorsal genes. The inhibition activity of XSox17β maps to a region C-terminal to the HMG box; this region of XSox17β physically interacts with the Armadillo repeats of β-catenin. Two additional Sox proteins, XSox17α and XSox3, likewise bind to β-catenin and inhibit its TCF-mediated signaling activity. These results reveal an unexpected mechanism by which Sox proteins can modulate Wnt signaling pathways.

Original languageEnglish (US)
Pages (from-to)487-498
Number of pages12
JournalMolecular cell
Issue number4
StatePublished - Oct 1999

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Regulation of Wnt signaling by Sox proteins: XSox17α/β and XSox3 physically interact with β-catenin'. Together they form a unique fingerprint.

Cite this