Proteomic profiling of the TRAF3 interactome network reveals a new role for the ER-to-Golgi transport compartments in innate immunity.
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.
Faculty of Pharmacy, Université de Montréal, Montréal, Québec Canada.
Wendy J
WJ
van Zuylen
Priscilla
P
Doyon
Jean-François
JF
Clément
Kashif Aziz
KA
Khan
Lisa M
LM
D'Ambrosio
Florence
F
Dô
Myriam
M
St-Amant-Verret
Tasheen
T
Wissanji
Gregory
G
Emery
Anne-Claude
AC
Gingras
Sylvain
S
Meloche
Marc J
MJ
Servant
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D020869:Gene Expression Profiling; D006056:Golgi Apparatus / Q000378:metabolism*; D000077614:Golgi Matrix Proteins; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D007113:Immunity, Innate; D050838:Interferon Regulatory Factor-3 / Q000037:antagonists & inhibitors / Q000378:metabolism; D016899:Interferon-beta / Q000096:biosynthesis / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021381:Protein Transport; D020543:Proteome; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000378:metabolism; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D048008:TNF Receptor-Associated Factor 3 / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D000077614:Golgi Matrix Proteins; C484290:IFIT1 protein, human; C494232:IRF3 protein, human; D050838:Interferon Regulatory Factor-3; C505371:MAVS protein, human; D016328:NF-kappa B; D020543:Proteome; D012330:RNA, Double-Stranded; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C517555:SEC16A protein, human; D048008:TNF Receptor-Associated Factor 3; C090656:TRAF3 protein, human; D014157:Transcription Factors; D033921:Vesicular Transport Proteins; C091580:vesicular transport factor p115; D016899:Interferon-beta; D004247:DNA; D017346:Protein Serine-Threonine Kinases; C403191:TBK1 protein, human