Fine-tuning of nuclear-catenin by Chibby and 14-3-3

Cell Cycle. 2009 Jan 15;8(2):210-3. doi: 10.4161/cc.8.2.7394. Epub 2009 Jan 12.

Abstract

Chibby (Cby) is an evolutionarily conserved antagonist of beta-catenin, a central player of the canonical Wnt signaling pathway, which acts as a transcriptional coactivator. Cby physically interacts with the C-terminal activation domain of beta-catenin and blocks its transcriptional activation potential through competition with DNA-binding Tcf/Lef transcription factors. Our recent study revealed a second mechanism for Cby-mediated beta-catenin inhibition in which Cby cooperates with 14-3-3 adaptor proteins to facilitate nuclear export of beta-catenin, following phosphorylation of Cby by Akt kinase. Therefore, our findings unravel a novel molecular mechanism regulating the dynamic nucleo-cytoplasmic trafficking of beta-catenin and provide new insights into the cross-talk between the Wnt and Akt signaling pathways. Here, we review recent literature concerning Cby function and discuss our current understanding of the relationship between Wnt and Akt signaling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • 14-3-3 Proteins / metabolism*
  • Animals
  • Catenins / metabolism*
  • Cell Nucleus / metabolism*
  • Humans
  • Models, Biological
  • Nuclear Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Wnt Proteins / metabolism

Substances

  • 14-3-3 Proteins
  • Catenins
  • Nuclear Proteins
  • Wnt Proteins
  • Proto-Oncogene Proteins c-akt