title: DDX60, a DEXD/H box helicase, is a novel antiviral factor promoting RIG-I-like receptor-mediated signaling.
abstract: The cytoplasmic viral RNA sensors RIG-I and MDA5 are important for the production of type I interferon and other inflammatory cytokines. DDX60 is an uncharacterized DEXD/H box RNA helicase similar to Saccharomyces cerevisiae Ski2, a cofactor of RNA exosome, which is a protein complex required for the integrity of cytoplasmic RNA. Expression of DDX60 increases after viral infection, and the protein localizes at the cytoplasmic region. After viral infection, the DDX60 protein binds to endogenous RIG-I protein. The protein also binds to MDA5 and LGP2 but not to the downstream factors IPS-1 and IκB kinase ε (IKK-ε). Knockdown analysis shows that DDX60 is required for RIG-I- or MDA5-dependent type I interferon and interferon-inducible gene expression in response to viral infection. However, DDX60 is dispensable for TLR3-mediated signaling. Purified DDX60 helicase domains possess the activity to bind to viral RNA and DNA. Expression of DDX60 promotes the binding of RIG-I to double-stranded RNA. Taken together, our analyses indicate that DDX60 is a novel antiviral helicase promoting RIG-I-like receptor-mediated signaling.
authors.affiliation: Department of Microbiology and Immunology, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Moeko
authors.initials: M
authors.lastname: Miyashita
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oshiumi
authors.forename: Misako
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Seya
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D002522:Chlorocebus aethiops; D003588:Cytopathogenic Effect, Viral; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism; D055354:Exosomes / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D018259:Herpesvirus 1, Human / Q000502:physiology; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D007370:Interferon Type I / Q000096:biosynthesis / Q000235:genetics; D000072640:Interferon-Induced Helicase, IFIH1; D051379:Mice; D008822:Mice, Transgenic; D046228:Microarray Analysis; D017955:Poliovirus / Q000502:physiology; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D011971:Receptors, Immunologic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029082:Sendai virus / Q000502:physiology; D015398:Signal Transduction; D051196:Toll-Like Receptor 3; D014709:Vero Cells; D014721:Vesicular stomatitis Indiana virus / Q000502:physiology; D018406:Virus Physiological Phenomena; D014779:Virus Replication
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D004279:DNA, Viral; D007370:Interferon Type I; C505371:MAVS protein, human; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D011971:Receptors, Immunologic; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D051550:I-kappa B Kinase; C520569:DHX58 protein, human; C452820:RIGI protein, human; C561888:DDX60 protein, human; C561889:DDX60 protein, mouse; C452815:IFIH1 protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases; D000072640:Interferon-Induced Helicase, IFIH1; D020365:RNA Helicases