E3 ubiquitin ligase ASB8 negatively regulates interferon via regulating TBK1/IKKi homeostasis

Mol Immunol. 2020 May:121:195-203. doi: 10.1016/j.molimm.2020.03.011. Epub 2020 Apr 14.

Abstract

Cells recognize virus nucleic acid by pattern recognition receptors (PRRs), virus involve in the activation of signaling cascade of variable adaptor proteins, TANK-binding kinase1(TBK1)/ inhibitor of nuclear factor kappa-B kinase subunit epsilon(IKKi) complex, IκB kinase(IKKs) to trigger activation of transcription factor, interferon regulatory factor 3/7(IRF3/7), ultimately, leading to the production of type I interferon and exert anti-viral effects. In this study, E3 ubiquitin ligase ankyrin repeat and SOCS box-containing 8(ASB8) interacted with TBK1/IKKi and phosphorylation modification of ASB8 at site of Ser17 to further strengthen its ubiquitination activity were verified. Conversely, phosphorylated ASB8 accelerate K48-linked ubiquitination and degradation of TBK1/IKKi, which further reduces phosphorylation level of IRF3 and inhibits production of IFN-β. At the same time, a new bridge molecule Leucine-rich repeat containing protein 10B(LRRC10B) upregulated after viral infection are involved in the formation and interaction with ASB8-TBK1/IKKi complex was reported. Our study reveals a new mechanism of ubiquitin ligase ASB8 modulating antiviral innate immunity by altering stability of TBK1/IKKi kinase complex.

Keywords: Ankyrin repeat and SOCS box–containing 8 (ASB8); Inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKKi); Leucine-rich repeat containing protein 10B(LRRC10B); Phosphorylation; TANK-binding kinase1 (TBK1); Ubiquitination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • HEK293 Cells
  • HeLa Cells
  • Humans
  • I-kappa B Kinase / immunology
  • I-kappa B Kinase / metabolism*
  • Immunity, Innate
  • Interferon Regulatory Factor-3 / metabolism
  • Interferon Regulatory Factor-7 / metabolism
  • Interferon-beta / immunology
  • Interferon-beta / metabolism*
  • Phosphorylation / immunology
  • Protein Serine-Threonine Kinases / immunology
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA, Small Interfering / metabolism
  • Serine / metabolism
  • Signal Transduction / immunology
  • Suppressor of Cytokine Signaling Proteins / genetics
  • Suppressor of Cytokine Signaling Proteins / immunology
  • Suppressor of Cytokine Signaling Proteins / metabolism*
  • Ubiquitin-Protein Ligases / immunology
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination / immunology

Substances

  • ASB8 protein, human
  • IRF3 protein, human
  • IRF7 protein, human
  • Interferon Regulatory Factor-3
  • Interferon Regulatory Factor-7
  • RNA, Small Interfering
  • Suppressor of Cytokine Signaling Proteins
  • Serine
  • Interferon-beta
  • Ubiquitin-Protein Ligases
  • Protein Serine-Threonine Kinases
  • TBK1 protein, human
  • I-kappa B Kinase
  • IKBKE protein, human