Negative regulation of TLR inflammatory signaling by the SUMO-deconjugating enzyme SENP6

PLoS Pathog. 2013;9(6):e1003480. doi: 10.1371/journal.ppat.1003480. Epub 2013 Jun 27.

Abstract

The signaling of Toll-like receptors (TLRs) induces host defense against microbial invasion. Protein posttranslational modifications dynamically shape the strength and duration of the signaling pathways. It is intriguing to explore whether de-SUMOylation could modulate the TLR signaling. Here we identified SUMO-specific protease 6 (SENP6) as an intrinsic attenuator of the TLR-triggered inflammation. Depletion of SENP6 significantly potentiated the NF-κB-mediated induction of the proinflammatory genes. Consistently, SENP6-knockdown mice were more susceptible to endotoxin-induced sepsis. Mechanistically, the small ubiquitin-like modifier 2/3 (SUMO-2/3) is conjugated onto the Lysine residue 277 of NF-κB essential modifier (NEMO/IKKγ), and this impairs the deubiquitinase CYLD to bind NEMO, thus strengthening the inhibitor of κB kinase (IKK) activation. SENP6 reverses this process by catalyzing the de-SUMOylation of NEMO. Our study highlights the essential function of the SENP family in dampening TLR signaling and inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / immunology
  • Cysteine Endopeptidases / metabolism*
  • Deubiquitinating Enzyme CYLD
  • Endotoxins / toxicity
  • Humans
  • I-kappa B Kinase / genetics
  • I-kappa B Kinase / immunology
  • I-kappa B Kinase / metabolism
  • Inflammation / chemically induced
  • Inflammation / genetics
  • Inflammation / immunology
  • Inflammation / metabolism
  • Inflammation / pathology
  • Intracellular Signaling Peptides and Proteins / immunology
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Mice
  • Mice, Knockout
  • Sepsis / chemically induced
  • Sepsis / genetics
  • Sepsis / immunology
  • Sepsis / metabolism
  • Sepsis / pathology
  • Signal Transduction*
  • Small Ubiquitin-Related Modifier Proteins / genetics
  • Small Ubiquitin-Related Modifier Proteins / immunology
  • Small Ubiquitin-Related Modifier Proteins / metabolism*
  • Sumoylation / genetics
  • Sumoylation / immunology
  • Toll-Like Receptors / genetics
  • Toll-Like Receptors / immunology
  • Toll-Like Receptors / metabolism*
  • Ubiquitins / genetics
  • Ubiquitins / immunology
  • Ubiquitins / metabolism*

Substances

  • Endotoxins
  • Intracellular Signaling Peptides and Proteins
  • NEMO protein, mouse
  • SUMO2 protein, mouse
  • Small Ubiquitin-Related Modifier Proteins
  • Sumo3 protein, mouse
  • Toll-Like Receptors
  • Ubiquitins
  • I-kappa B Kinase
  • CYLD protein, mouse
  • Deubiquitinating Enzyme CYLD
  • Cysteine Endopeptidases

Grants and funding

This work was supported by grants from National Natural Science Foundation of China (31030021, 81161120542) and Ministry of Science and Technology of China (2012CB910200, 2011CB910900, 2010CB529703). XL was supported by China Postdoctoral Science Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.