1. TRIM68 negatively regulates IFN-β production by degrading TRK fused gene, a novel driver of IFN-β downstream of anti-viral detection systems.
- Author
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Wynne C, Lazzari E, Smith S, McCarthy EM, Ní Gabhann J, Kallal LE, Higgs R, Greco A, Cryan SA, Biron CA, and Jefferies CA
- Subjects
- Autoantigens chemistry, DEAD Box Protein 58, DEAD-box RNA Helicases metabolism, HEK293 Cells, HeLa Cells, Humans, Interferon-beta genetics, Promoter Regions, Genetic genetics, Protein Structure, Tertiary, Proteolysis, Receptors, Immunologic, Tripartite Motif Proteins, Ubiquitin-Protein Ligases chemistry, Ubiquitin-Protein Ligases deficiency, Ubiquitination, Autoantigens metabolism, Immunity, Innate, Interferon-beta biosynthesis, Proteins metabolism, Ubiquitin-Protein Ligases metabolism, Viruses immunology
- Abstract
In recent years members of the tripartite motif-containing (TRIM) family of E3 ubiquitin ligases have been shown to both positively and negatively regulate viral defence and as such are emerging as compelling targets for modulating the anti-viral immune response. In this study we identify TRIM68, a close homologue of TRIM21, as a novel regulator of Toll-like receptor (TLR)- and RIG-I-like receptor (RLR)-driven type I IFN production. Proteomic analysis of TRIM68-containing complexes identified TRK-fused gene (TFG) as a potential TRIM68 target. Overexpression of TRIM68 and TFG confirmed their ability to associate, with TLR3 stimulation appearing to enhance the interaction. TFG is a known activator of NF-κB via its ability to interact with inhibitor of NF-κB kinase subunit gamma (IKK-γ) and TRAF family member-associated NF-κB activator (TANK). Our data identifies a novel role for TFG as a positive regulator of type I IFN production and suggests that TRIM68 targets TFG for lysosomal degradation, thus turning off TFG-mediated IFN-β production. Knockdown of TRIM68 in primary human monocytes resulted in enhanced levels of type I IFN and TFG following poly(I:C) treatment. Thus TRIM68 targets TFG, a novel regulator of IFN production, and in doing so turns off and limits type I IFN production in response to anti-viral detection systems.
- Published
- 2014
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