NRAGE induces β-catenin/Arm O-GlcNAcylation and negatively regulates Wnt signaling

Biochem Biophys Res Commun. 2017 May 27;487(2):433-437. doi: 10.1016/j.bbrc.2017.04.080. Epub 2017 Apr 17.

Abstract

The Wnt pathway is crucial for animal development, as well as tumor formation. Understanding the regulation of Wnt signaling will help to elucidate the mechanism of the cell cycle, cell differentiation and tumorigenesis. It is generally accepted that in response to Wnt signals, β-catenin accumulates in the cytoplasm and is imported into the nucleus where it recruits LEF/TCF transcription factors to activate the expression of target genes. In this study, we report that human NRAGE, a neurotrophin receptor p75 (p75NTR) binding protein, markedly suppresses the expression of genes activated by the Wnt pathway. Consistent with this finding, loss of function of NRAGE by RNA interference (RNAi) activates the Wnt pathway. Moreover, NRAGE suppresses the induction of axis duplication by microinjected β-catenin in Xenopus embryos. To our surprise, NRAGE induces nuclear localization of β-catenin and increases its DNA binding ability. Further studies reveal that NRAGE leads to the modification of β-catenin/Arm with O-linked beta-N-acetylglucosamine (O-GlcNAc), and failure of the association between β-catenin/Arm and pygopus(pygo) protein, which is required for transcriptional activation of Wnt target genes. Therefore, our findings suggest a novel mechanism for regulating Wnt signaling.

Keywords: NRAGE; O-GlcNAc; Wnt; β-catenin/Arm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylglucosamine / metabolism*
  • Acylation / physiology
  • Antigens, Neoplasm / metabolism*
  • Armadillo Domain Proteins / metabolism
  • Cell Nucleus / metabolism
  • DNA / metabolism*
  • Down-Regulation / physiology
  • HEK293 Cells
  • Humans
  • N-Acetylglucosaminyltransferases / metabolism*
  • Neoplasm Proteins / metabolism*
  • Wnt Signaling Pathway / physiology*
  • beta Catenin / metabolism*

Substances

  • Antigens, Neoplasm
  • Armadillo Domain Proteins
  • CTNNB1 protein, human
  • MAGED1 protein, human
  • Neoplasm Proteins
  • beta Catenin
  • DNA
  • N-Acetylglucosaminyltransferases
  • Acetylglucosamine