title: Targeting the viral Achilles' heel: recognition of 5'-triphosphate RNA in innate anti-viral defence.
abstract: Some RNA virus genomes bear 5'-triphosphates, which can be recognized in the cytoplasm of infected cells by host proteins that mediate anti-viral immunity. Both the innate sensor RIG-I and the interferon-induced IFIT proteins bind to 5'-triphosphate viral RNAs. RIG-I signals for induction of interferons during RNA virus infection while IFITs sequester viral RNAs to exert an anti-viral effect. Notably, the structures of these proteins reveal both similarities and differences, which are suggestive of independent evolution towards ligand binding. 5'-triphosphates, which are absent from most RNAs in the cytosol of uninfected cells, are thus a marker of virus infection that is targeted by the innate immune system for both induction and execution of the anti-viral response.
authors.affiliation: Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, UK. jan.rehwinkel@imm.ox.ac.uk
authors.forename: Jan
authors.initials: J
authors.lastname: Rehwinkel
authors.forename: Caetano
authors.initials: C
authors.lastname: Reis e Sousa
mesh_terms: D000818:Animals; D002352:Carrier Proteins; D053487:DEAD-box RNA Helicases; D006801:Humans; D007113:Immunity, Innate; D012328:RNA Viruses / Q000276:immunology*; D012367:RNA, Viral / Q000276:immunology* / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D053487:DEAD-box RNA Helicases