The inhibitory effects of Disabled-2 (Dab2) on Wnt signaling are mediated through Axin

Oncogene. 2008 Mar 20;27(13):1865-75. doi: 10.1038/sj.onc.1210829. Epub 2007 Oct 8.

Abstract

beta-Catenin-mediated Wnt signaling is essential in embryonic development and in adult tissues. Recent studies have demonstrated that Axin not only plays an important inhibitory role in coordinating beta-catenin degradation, but is itself degraded by the low-density-lipoprotein receptor-related protein (LRP)5/6 Wnt co-receptor. Here, we demonstrate that the endocytic adaptor molecule Disabled-2 (Dab2), which we have previously demonstrated to act as an inhibitor of beta-catenin signaling, interacts with Axin and prevents its interaction with and degradation by the LRP5 co-receptor, thereby increasing its half-life and stabilization. Dab2 levels induced during retinoic acid-induced differentiation of F9, or during transforming growth factor-beta-induced epithelial-mesenchymal transdifferentiation of mouse mammary epithelial cells result in the stabilization of Axin and concomitant inhibition of beta-catenin signaling. Ectopic expression of Dab2 in F9 cells as well as in transformed cell lines results in increased Axin expression and attenuation of Wnt-mediated signaling. We conclude that Dab2 may play an important role in the maintenance of the differentiated state and restrain Wnt-mediated proliferation through its association with and modulation of Axin.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Adaptor Proteins, Vesicular Transport / pharmacology*
  • Animals
  • Apoptosis Regulatory Proteins
  • Axin Protein
  • Blotting, Western
  • Carcinoma, Embryonal / metabolism
  • Carcinoma, Embryonal / pathology*
  • Cell Differentiation / drug effects
  • Cell Proliferation
  • Epithelial Cells / metabolism
  • Immunoprecipitation
  • Mesoderm / cytology
  • Mesoderm / metabolism
  • Mice
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction*
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism
  • Tretinoin / pharmacology
  • Wnt Proteins / antagonists & inhibitors
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism*
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Adaptor Proteins, Vesicular Transport
  • Apoptosis Regulatory Proteins
  • Axin Protein
  • CTNNB1 protein, mouse
  • Dab2 protein, mouse
  • Repressor Proteins
  • Transforming Growth Factor beta
  • Wnt Proteins
  • beta Catenin
  • Tretinoin