title: A Conserved Histidine in the RNA Sensor RIG-I Controls Immune Tolerance to N1-2'O-Methylated Self RNA.
abstract: The cytosolic helicase retinoic acid-inducible gene-I (RIG-I) initiates immune responses to most RNA viruses by detecting viral 5'-triphosphorylated RNA (pppRNA). Although endogenous mRNA is also 5'-triphosphorylated, backbone modifications and the 5'-ppp-linked methylguanosine ((m7)G) cap prevent immunorecognition. Here we show that the methylation status of endogenous capped mRNA at the 5'-terminal nucleotide (N1) was crucial to prevent RIG-I activation. Moreover, we identified a single conserved amino acid (H830) in the RIG-I RNA binding pocket as the mediator of steric exclusion of N1-2'O-methylated RNA. H830A alteration (RIG-I(H830A)) restored binding of N1-2'O-methylated pppRNA. Consequently, endogenous mRNA activated the RIG-I(H830A) mutant but not wild-type RIG-I. Similarly, knockdown of the endogenous N1-2'O-methyltransferase led to considerable RIG-I stimulation in the absence of exogenous stimuli. Studies involving yellow-fever-virus-encoded 2'O-methyltransferase and RIG-I(H830A) revealed that viruses exploit this mechanism to escape RIG-I. Our data reveal a new role for cap N1-2'O-methylation in RIG-I tolerance of self-RNA.
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Schuberth-Wagner
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Janos
authors.initials: J
authors.lastname: Ludwig
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Ann Kristin
authors.initials: AK
authors.lastname: Bruder
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Anna-Maria
authors.initials: AM
authors.lastname: Herzner
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany; German Center for Infection Research Cologne-Bonn.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zillinger
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Goldeck
authors.affiliation: Institute of Molecular Medicine, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schmidt
authors.affiliation: Institute of Molecular Medicine, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Schmid-Burgk
authors.affiliation: Department of Virology, Bernhard-Nocht-Institute for Tropical Medicine, 20259 Hamburg, Germany.
authors.forename: Romy
authors.initials: R
authors.lastname: Kerber
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Steven
authors.initials: S
authors.lastname: Wolter
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Jan-Philip
authors.initials: JP
authors.lastname: Stümpel
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Roth
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Bartok
authors.affiliation: Institute of Virology, University of Bonn Medical Centre, 53127 Bonn, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Drosten
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Coch
authors.affiliation: Institute of Molecular Medicine, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Veit
authors.initials: V
authors.lastname: Hornung
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany; German Center for Infection Research Cologne-Bonn.
authors.forename: Winfried
authors.initials: W
authors.lastname: Barchet
authors.affiliation: Institute of Virology, University of Bonn Medical Centre, 53127 Bonn, Germany.
authors.forename: Beate M
authors.initials: BM
authors.lastname: Kümmerer
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany.
authors.forename: Gunther
authors.initials: G
authors.lastname: Hartmann
authors.affiliation: Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital, University of Bonn, 53105 Bonn, Germany. Electronic address: martin.schlee@uni-bonn.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Schlee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics*; D004789:Enzyme Activation / Q000235:genetics / Q000276:immunology; D006639:Histidine / Q000235:genetics; D006801:Humans; D007108:Immune Tolerance / Q000235:genetics*; D008745:Methylation; D008780:Methyltransferases / Q000235:genetics; D051379:Mice; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D012367:RNA, Viral / Q000276:immunology; D011971:Receptors, Immunologic; D015005:Yellow fever virus / Q000201:enzymology* / Q000235:genetics
chemical_list: C551867:5'PPP-RNA; D012367:RNA, Viral; D011971:Receptors, Immunologic; D006639:Histidine; D012313:RNA; D008780:Methyltransferases; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases
keywords: 2′O-methyl; 5′-triphosphate RNA; MTr1; RIG-I; cap; immune recognition of RNA; innate immune tolerance mechanism; mRNA; virus