Inhibition of Canonical NF-κB Signaling by a Small Molecule Targeting NEMO-Ubiquitin Interaction

Sci Rep. 2016 Jan 7;6:18934. doi: 10.1038/srep18934.

Abstract

The IκB kinase (IKK) complex acts as the gatekeeper of canonical NF-κB signaling, thereby regulating immunity, inflammation and cancer. It consists of the catalytic subunits IKKα and IKKβ and the regulatory subunit NEMO/IKKγ. Here, we show that the ubiquitin binding domain (UBAN) in NEMO is essential for IKK/NF-κB activation in response to TNFα, but not IL-1β stimulation. By screening a natural compound library we identified an anthraquinone derivative that acts as an inhibitor of NEMO-ubiquitin binding (iNUB). Using biochemical and NMR experiments we demonstrate that iNUB binds to NEMOUBAN and competes for interaction with methionine-1-linked linear ubiquitin chains. iNUB inhibited NF-κB activation upon UBAN-dependent TNFα and TCR/CD28, but not UBAN-independent IL-1β stimulation. Moreover, iNUB was selectively killing lymphoma cells that are addicted to chronic B-cell receptor triggered IKK/NF-κB activation. Thus, iNUB disrupts the NEMO-ubiquitin protein-protein interaction interface and thereby inhibits physiological and pathological NF-κB signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthraquinones / pharmacology*
  • Drug Evaluation, Preclinical
  • HeLa Cells
  • Humans
  • Interleukin-1beta / physiology
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Mice
  • NF-kappa B / metabolism*
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Signal Transduction / drug effects*
  • Tumor Necrosis Factor-alpha / physiology
  • Ubiquitin / metabolism*
  • Ubiquitination

Substances

  • Anthraquinones
  • Interleukin-1beta
  • Intracellular Signaling Peptides and Proteins
  • NEMO protein, mouse
  • NF-kappa B
  • TNF protein, human
  • Tumor Necrosis Factor-alpha
  • Ubiquitin