title: The Broad-Spectrum Antiviral Protein ZAP Restricts Human Retrotransposition.
abstract: Intrinsic immunity describes the set of recently discovered but poorly understood cellular mechanisms that specifically target viral pathogens. Their discovery derives in large part from intensive studies of HIV and SIV that revealed restriction factors acting at various stages of the retroviral life cycle. Recent studies indicate that some factors restrict both retroviruses and retrotransposons but surprisingly in ways that may differ. We screened known interferon-stimulated antiviral proteins previously untested for their effects on cell culture retrotransposition. Several factors, including BST2, ISG20, MAVS, MX2, and ZAP, showed strong L1 inhibition. We focused on ZAP (PARP13/ZC3HAV1), a zinc-finger protein that targets viruses of several families, including Retroviridae, Tiloviridae, and Togaviridae, and show that ZAP expression also strongly restricts retrotransposition in cell culture through loss of L1 RNA and ribonucleoprotein particle integrity. Association of ZAP with the L1 ribonucleoprotein particle is supported by co-immunoprecipitation and co-localization with ORF1p in cytoplasmic stress granules. We also used mass spectrometry to determine the protein components of the ZAP interactome, and identified many proteins that directly interact and colocalize with ZAP, including MOV10, an RNA helicase previously shown to suppress retrotransposons. The detection of a chaperonin complex, RNA degradation proteins, helicases, post-translational modifiers, and components of chromatin modifying complexes suggest mechanisms of ZAP anti-retroelement activity that function in the cytoplasm and perhaps also in the nucleus. The association of the ZAP ribonucleoprotein particle with many interferon-stimulated gene products indicates it may be a key player in the interferon response.
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: John L
authors.initials: JL
authors.lastname: Goodier
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Gavin C
authors.initials: GC
authors.lastname: Pereira
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Ling E
authors.initials: LE
authors.lastname: Cheung
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Rose
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Haig H
authors.initials: HH
authors.lastname: Kazazian
mesh_terms: D003001:Cloning, Molecular; D004267:DNA Viruses / Q000235:genetics; D019143:Evolution, Molecular; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D050835:Interferon Regulatory Factors / Q000235:genetics / Q000378:metabolism; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018626:Retroelements
chemical_list: D050835:Interferon Regulatory Factors; D016601:RNA-Binding Proteins; D018626:Retroelements; C527496:ZC3HAV1 protein, human; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C530476:Mov10 protein, human; D020365:RNA Helicases