A20 regulates canonical wnt-signaling through an interaction with RIPK4

PLoS One. 2018 May 2;13(5):e0195893. doi: 10.1371/journal.pone.0195893. eCollection 2018.

Abstract

A20 is a ubiquitin-editing enzyme that is known to regulate inflammatory signaling and cell death. However, A20 mutations are also frequently found in multiple malignancies suggesting a potential role as a tumor suppressor as well. We recently described a novel role for A20 in regulating the wnt-beta-catenin signaling pathway and suppressing colonic tumor development in mice. The underlying mechanisms for this phenomenon are unclear. To study this, we first generated A20 knockout cell lines by genome-editing techniques. Using these cells, we show that loss of A20 causes dysregulation of wnt-dependent gene expression by RNAseq. Mechanistically, A20 interacts with a proximal signaling component of the wnt-signaling pathway, receptor interacting protein kinase 4 (RIPK4), and regulation of wnt-signaling by A20 occurs through RIPK4. Finally, similar to the mechanism by which A20 regulates other members of the receptor interacting protein kinase family, A20 modifies ubiquitin chains on RIPK4 suggesting a possible molecular mechanism for A20's control over the wnt-signaling pathway.

Publication types

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

MeSH terms

  • Gene Expression Regulation
  • Gene Knockout Techniques
  • Humans
  • Protein Binding
  • Protein-Serine-Threonine Kinases / metabolism*
  • Tumor Necrosis Factor alpha-Induced Protein 3 / deficiency
  • Tumor Necrosis Factor alpha-Induced Protein 3 / genetics
  • Tumor Necrosis Factor alpha-Induced Protein 3 / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism
  • Ubiquitination
  • Wnt Signaling Pathway*

Substances

  • Tumor Necrosis Factor-alpha
  • RIPK4 protein, human
  • Protein-Serine-Threonine Kinases
  • TNFAIP3 protein, human
  • Tumor Necrosis Factor alpha-Induced Protein 3