Key roles for phosphorylation and the Coiled-coil domain in TRIM56-mediated positive regulation of TLR3-TRIF-dependent innate immunity

Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved..

Tripartite-motif protein-56 (TRIM56) positively regulates the induction of type I interferon response via the TLR3 pathway by enhancing IRF3 activation and depends on its C-terminal residues 621-750 for interacting with the adaptor TRIF. However, the precise underlying mechanism and detailed TRIM56 determinants remain unclear. Herein, we show ectopic expression of murine TRIM56 also enhances TLR3-dependent interferon-β promoter activation, suggesting functional conservation. We found that endogenous TRIM56 and TRIF formed a complex early (0.5-2 h) after poly-I:C stimulation and that TRIM56 overexpression also promoted activation of NF-κB by poly-I:C but not that by TNF-α or IL-1β, consistent with a specific effect on TRIF prior to the bifurcation of NF-κB and IRF3. Using transient transfection and Tet-regulated cell lines expressing various TRIM56 mutants, we demonstrated the Coiled-coil domain and a segment spanning residues ∼434-610, but not the B-box or residues 355-433, were required for TRIM56 augmentation of TLR3 signaling. Moreover, alanine substitution at each putative phosphorylation site, Ser471, Ser475, and Ser710, abrogated TRIM56 function. Concordantly, mutants bearing Ser471Ala, Ser475Ala, or Ser710Ala, or lacking the Coiled-coil domain, all lost the capacity to enhance poly-I:C-induced establishment of an antiviral state. Furthermore, the Ser710Ala mutation disrupted the TRIM56-TRIF association. Using phospho-specific antibodies, we detected biphasic phosphorylation of TRIM56 at Ser471 and Ser475 following TLR3 stimulation, with the early phase occurring at ∼0.5 to 1 h, prior to IRF3 phosphorylation. Together, these data reveal novel molecular details critical for the TRIM56 augmentation of TLR3-dependent antiviral response and highlight important roles for TRIM56 scaffolding and phosphorylation.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:300

Enthalten in:

The Journal of biological chemistry - 300(2024), 5 vom: 29. März, Seite 107249

Sprache:

Englisch

Beteiligte Personen:

Liu, Benjamin M [VerfasserIn]
Li, Nan L [VerfasserIn]
Wang, Ruixue [VerfasserIn]
Li, Xiaofan [VerfasserIn]
Li, Z Alex [VerfasserIn]
Marion, Tony N [VerfasserIn]
Li, Kui [VerfasserIn]

Links:

Volltext

Themen:

Antiviral state
Coiled-coil domain
IRF3
Interferon
Journal Article
NF-kappaB
Phosphorylation
TRIF
TRIM56
Toll-like receptor-3

Anmerkungen:

Date Revised 27.04.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1016/j.jbc.2024.107249

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370456041