β-catenin is O-GlcNAc glycosylated at Serine 23: implications for β-catenin's subcellular localization and transactivator function

Exp Cell Res. 2014 Feb 15;321(2):153-66. doi: 10.1016/j.yexcr.2013.11.021. Epub 2013 Dec 14.

Abstract

Background: We have previously reported that β-catenin is post-translationally modified with a single O-linked attachment of β-N-acetyl-glucosamine (O-GlcNAc). We showed that O-GlcNAc regulated β-catenin's subcellular localization and transcriptional activity.

Objective: The objectives of this investigation were to identify the putative O-GlcNAc sites of β-catenin and the relevance of identified sites in the regulation of β-catenin's localization and transcriptional activity.

Method: Missense mutations were introduced to potential O-GlcNAc sites of pEGFP-C2-N-Terminal- or pEGFP-C2-Wild Type-β-catenin by site-directed mutagenesis. We determined the levels of O-GlcNAc-β-catenin, subcellular localization, interaction with binding partners and transcriptional activity of the various constructs.

Results: Serine 23 of β-catenin was determined as a site for O-GlcNAc modification which regulated its subcellular distribution, its interactions with cellular partners and consequently its transcriptional activity.

Significance: O-GlcNAcylation of Serine 23 is a novel regulatory modification for β-catenin's subcellular localization and transcriptional activity. This study is the first report to characterize site specific regulation of β-catenin by the O-GlcNAc modification.

Keywords: O-GlcNAcylation; Subcellular localization; Transcriptional function; β-Catenin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylglucosamine / metabolism*
  • Glycosylation
  • Humans
  • Phosphorylation
  • Protein Binding
  • Protein Processing, Post-Translational*
  • Protein Structure, Tertiary
  • Protein Transport
  • Serine / metabolism*
  • Tissue Distribution
  • Trans-Activators / chemistry
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*
  • Transcriptional Activation* / physiology
  • Tumor Cells, Cultured
  • beta Catenin / chemistry
  • beta Catenin / genetics
  • beta Catenin / metabolism*

Substances

  • Trans-Activators
  • beta Catenin
  • Serine
  • Acetylglucosamine