Scientific article
OA Policy
English

Ubiquitin systems mark pathogen-containing vacuoles as targets for host defense by guanylate binding proteins

Publication date2015-10-13
First online date2015-09-28
Abstract

Many microbes create and maintain pathogen-containing vacuoles (PVs) as an intracellular niche permissive for microbial growth and survival. The destruction of PVs by IFNγ-inducible guanylate binding protein (GBP) and immunity-related GTPase (IRG) host proteins is central to a successful immune response directed against numerous PV-resident pathogens. However, the mechanism by which IRGs and GBPs cooperatively detect and destroy PVs is unclear. We find that host cell priming with IFNγ prompts IRG-dependent association of Toxoplasma- and Chlamydia-containing vacuoles with ubiquitin through regulated translocation of the E3 ubiquitin ligase tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6). This initial ubiquitin labeling elicits p62-mediated escort and deposition of GBPs to PVs, thereby conferring cell-autonomous immunity. Hypervirulent strains of Toxoplasma gondii evade this process via specific rhoptry protein kinases that inhibit IRG function, resulting in blockage of downstream PV ubiquitination and GBP delivery. Our results define a ubiquitin-centered mechanism by which host cells deliver GBPs to PVs and explain how hypervirulent parasites evade GBP-mediated immunity.

Keywords
  • Chlamydia
  • GBPs
  • Toxoplasma
  • Immunity-related GTPase
  • Interferon
UNIGE affiliation entities Not a UNIGE publication
Funding
  • American Heart Association [12PRE10440003]
  • National Institute of Health [R01AI103197]
  • MRC grant [MC_UP_1202/12]
  • The Francis Crick Institute [10076]
  • Medical Research Council [1243641]
  • NIGMS NIH HHS [T32 GM007184]
  • NIAID NIH HHS [R37 AI103197]
Citation (ISO format)
HALDAR, Arun K et al. Ubiquitin systems mark pathogen-containing vacuoles as targets for host defense by guanylate binding proteins. In: Proceedings of the National Academy of Sciences of the United States of America, 2015, vol. 112, n° 41, p. E5628–E5637. doi: 10.1073/pnas.1515966112
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Article (Published version)
Identifiers
Additional URL for this publicationhttps://pnas.org/doi/full/10.1073/pnas.1515966112
Journal ISSN0027-8424
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