• DOI:10.1074/jbc.M100194200
• Corpus ID: 204141547

Regulation of β-Catenin Structure and Activity by Tyrosine Phosphorylation*

@article{Piedra2001RegulationO,
  title={Regulation of $\beta$-Catenin Structure and Activity by Tyrosine Phosphorylation*},
  author={José A. Piedra and Daniel Martinez and Julio Casta{\~n}o and Susana Miravet and Mireia Du{\~n}ach and Antonio Garcı́a de Herreros},
  journal={The Journal of Biological Chemistry},
  year={2001},
  volume={276},
  pages={20436 - 20443}
}

• J. Piedra, D. Martinez, +3 authors A. G. de Herreros
• Published 8 June 2001
• Biology, Chemistry
• The Journal of Biological Chemistry

β-Catenin plays a dual role as a key effector in the regulation of adherens junctions and as a transcriptional coactivator. Phosphorylation of Tyr-654, a residue placed in the last armadillo repeat of β-catenin, decreases its binding to E-cadherin. We show here that phosphorylation of Tyr-654 also stimulates the association of β-catenin to the basal transcription factor TATA-binding protein. The structural bases of these different affinities were investigated. Our results indicate that the β-catenin C-terminal tail interacts with the armadillo repeat domain, hindering the association of the armadillo region to the TATA-binding protein or to E-cadherin. Phosphorylation of β-catenin Tyr-654 decreases armadillo-C-terminal tail association, uncovering the last armadillo repeats. In a C-terminal-depleted β-catenin, the presence of a negative charge at Tyr-654 does not affect the interaction of the TATA-binding protein to the armadillo domain. However, in the case of E-cadherin, the establishment of ion pairs dominates its association with β-catenin, and its binding is greatly dependent on the absence of a negative charge at Tyr-654. Thus, phosphorylation of Tyr-654 blocks the Ecadherin-β-catenin interaction, even though the steric hindrance of the C-tail is no longer present. These results explain how phosphorylation of β-catenin in Tyr-654 modifies the tertiary structure of this protein and the interaction with its different partners.