Citrobacter rodentium NleB Protein Inhibits Tumor Necrosis Factor (TNF) Receptor-associated Factor 3 (TRAF3) Ubiquitination to Reduce Host Type I Interferon Production

Xiaofei Gao; Thanh H. Pham; Leigh Ann Feuerbacher; Kangming Chen; Michael P. Hays; Gyanendra Singh; Christian Rueter; Ramon Hurtado-Guerrero; Philip R. Hardwidge

doi:10.1074/jbc.M116.738278

Citrobacter rodentium NleB Protein Inhibits Tumor Necrosis Factor (TNF) Receptor-associated Factor 3 (TRAF3) Ubiquitination to Reduce Host Type I Interferon Production*

From the ^‡Whitehead Institute, Cambridge, Massachusetts 02142,
^§Case Western Reserve University, Cleveland, Ohio 44106,
the ^¶College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506,
the ^‖National Institute of Occupational Health, Meghani Nagar, Ahmedabad 380016, Gujarat, India,
the ^**Institute of Infectiology, University of Münster, D-48149 Münster, Germany, and
the ^‡‡Fundacion ARAID, Edificio CEEI ARAGÓN and Institute of Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, 50018 Zaragoza, Spain

↵1 To whom correspondence should be addressed: Tel.: 785-532-2506; Fax: 785-532-4851; E-mail: hardwidg{at}vet.k-state.edu.

Abstract

Interferon signaling plays important roles in both intestinal homeostasis and in the host response to pathogen infection. The extent to which bacterial pathogens inhibit this host pathway is an understudied area of investigation. We characterized Citrobacter rodentium strains bearing deletions in individual type III secretion system effector genes to determine whether this pathogen inhibits the host type I IFN response and which effector is responsible. The NleB effector limited host IFN-β production by inhibiting Lys⁶³-linked ubiquitination of TNF receptor-associated factor 3 (TRAF3). Inhibition was dependent on the glycosyltransferase activity of NleB. GAPDH, a target of NleB during infection, bound to TRAF3 and was required for maximal TRAF3 ubiquitination. NleB glycosyltransferase activity inhibited GAPDH-TRAF3 binding, resulting in reduced TRAF3 ubiquitination. Collectively, our data reveal important interplay between GAPDH and TRAF3 and suggest a mechanism by which the NleB effector inhibits type I IFN signaling.

Footnotes

↵* This work was supported by NIAID, National Institutes of Health Grant AI093913. The authors declare that they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.