The E3 ubiquitin ligase RNF185 facilitates the cGAS-mediated innate immune response

PLoS Pathog. 2017 Mar 8;13(3):e1006264. doi: 10.1371/journal.ppat.1006264. eCollection 2017 Mar.

Abstract

The cyclic GMP-AMP synthase (cGAS), upon cytosolic DNA stimulation, catalyzes the formation of the second messenger 2'3'-cGAMP, which then binds to stimulator of interferon genes (STING) and activates downstream signaling. It remains to be elucidated how the cGAS enzymatic activity is modulated dynamically. Here, we reported that the ER ubiquitin ligase RNF185 interacted with cGAS during HSV-1 infection. Ectopic-expression or knockdown of RNF185 respectively enhanced or impaired the IRF3-responsive gene expression. Mechanistically, RNF185 specifically catalyzed the K27-linked poly-ubiquitination of cGAS, which promoted its enzymatic activity. Additionally, Systemic Lupus Erythematosus (SLE) patients displayed elevated expression of RNF185 mRNA. Collectively, this study uncovers RNF185 as the first E3 ubiquitin ligase of cGAS, shedding light on the regulation of cGAS activity in innate immune responses.

MeSH terms

  • Adolescent
  • Adult
  • Cells, Cultured
  • Female
  • Herpes Simplex / immunology
  • Herpesvirus 1, Human
  • Humans
  • Immunity, Innate / immunology*
  • Immunoblotting
  • Immunoprecipitation
  • Lupus Erythematosus, Systemic / immunology*
  • Male
  • Microscopy, Confocal
  • Middle Aged
  • Mitochondrial Proteins / immunology*
  • Nucleotidyltransferases / immunology*
  • RNA, Small Interfering
  • Real-Time Polymerase Chain Reaction
  • Transfection
  • Ubiquitin-Protein Ligases / immunology*
  • Young Adult

Substances

  • Mitochondrial Proteins
  • RNA, Small Interfering
  • RNF185 protein, human
  • Ubiquitin-Protein Ligases
  • Nucleotidyltransferases
  • cGAS protein, human

Grants and funding

This work was supported by grants from National Natural Science Foundation of China (81672029, 31601136, 31271563, 81572076), Ministry of Science and Technology of China (2016YFA0501800, 2016YFC1100200), and National Basic Research Program of China (2011CB944002). Dr. Qiang Wang is sponsored by Science and Technology Commission of Shanghai Municipality “Sailing Program” (16YF1413600) and China Postdoctoral Science Foundation (2016M590390). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.