Proteomic Profiling of the TRAF3 Interactome Network Reveals a New Role for the ER-to-Golgi Transport Compartments in Innate Immunity

PLoS Pathogens

Florence Dô¹  Sylvain Meloche²  Kashif Aziz Khan³  Priscilla Doyon³  Gregory Emery³  Wendy J. van Zuylen³  Jean-François Clément³  Myriam St-Amant-Verret³  Tasheen Wissanji³  Anne-Claude Gingras⁴  Lisa M. D'Ambrosio⁵  Marc J. Servant⁵ 

[1] Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada;Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada;Faculty of Pharmacy, Université de Montréal, Montréal, Québec Canada;Institut de Recherche en Immunologie et Cancérologie, Université de Montréal, Montréal, Québec, Canada;Samuel Lunenfeld Research Institute at Mount Sinai Hospital, Toronto, Ontario, Canada

关键词: HeLa cells;    293T cells;    Mitochondria;    Small interfering RNAs;    Golgi apparatus;    Confocal microscopy;    Immune response;    Interferons;   

DOI  :  10.1371/journal.ppat.1002747

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Tumor Necrosis Factor receptor-associated factor-3 (TRAF3) is a central mediator important for inducing type I interferon (IFN) production in response to intracellular double-stranded RNA (dsRNA). Here, we report the identification of Sec16A and p115, two proteins of the ER-to-Golgi vesicular transport system, as novel components of the TRAF3 interactome network. Notably, in non-infected cells, TRAF3 was found associated with markers of the ER-Exit-Sites (ERES), ER-to-Golgi intermediate compartment (ERGIC) and the cis-Golgi apparatus. Upon dsRNA and dsDNA sensing however, the Golgi apparatus fragmented into cytoplasmic punctated structures containing TRAF3 allowing its colocalization and interaction with Mitochondrial AntiViral Signaling (MAVS), the essential mitochondria-bound RIG-I-like Helicase (RLH) adaptor. In contrast, retention of TRAF3 at the ER-to-Golgi vesicular transport system blunted the ability of TRAF3 to interact with MAVS upon viral infection and consequently decreased type I IFN response. Moreover, depletion of Sec16A and p115 led to a drastic disorganization of the Golgi paralleled by the relocalization of TRAF3, which under these conditions was unable to associate with MAVS. Consequently, upon dsRNA and dsDNA sensing, ablation of Sec16A and p115 was found to inhibit IRF3 activation and anti-viral gene expression. Reciprocally, mild overexpression of Sec16A or p115 in Hec1B cells increased the activation of IFNβ, ISG56 and NF-κB -dependent promoters following viral infection and ectopic expression of MAVS and Tank-binding kinase-1 (TBK1). In line with these results, TRAF3 was found enriched in immunocomplexes composed of p115, Sec16A and TBK1 upon infection. Hence, we propose a model where dsDNA and dsRNA sensing induces the formation of membrane-bound compartments originating from the Golgi, which mediate the dynamic association of TRAF3 with MAVS leading to an optimal induction of innate immune responses.

【 授权许可】

CC BY