Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection

Sang Hyon Kim, Stuart Macfarlane, Natalia O. Kalinina, Daria V. Rakitina, Eugene V. Ryabov, Trudi Gillespie, Sophie Haupt, John W. S. Brown, Michael Taliansky

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    97 Citations (Scopus)

    Abstract

    The nucleolus and specific nucleolar proteins are involved in the life cycles of some plant and animal viruses, but the functions of these proteins and of nucleolar trafficking in virus infections are largely unknown. The ORF3 protein of the plant virus, groundnut rosette virus (an umbravirus), has been shown to cycle through the nucleus, passing through Cajal bodies to the nucleolus and then exiting back into the cytoplasm. This journey is absolutely required for the formation of viral ribonucleoprotein particles (RNPs) that, themselves, are essential for the spread of the virus to noninoculated leaves of the shoot tip. Here, we show that these processes rely on the interaction of the ORF3 protein with fibrillarin, a major nucleolar protein. Silencing of the fibrillarin gene prevents long-distance movement of groundnut rosette virus but does not affect viral replication or cell-to-cell movement. Repressing fibrillarin production also localizes the ORF3 protein to multiple Cajal body-like aggregates that fail to fuse with the nucleolus. Umbraviral ORF3 protein and fibrillarin interact in vitro and, when mixed with umbravirus RNA, form an RNP complex. This complex has a filamentous structure with some regular helical features, resembling the RNP complex formed in vivo during umbravirus infection. The filaments formed in vitro are infectious when inoculated to plants, and their infectivity is resistant to RNase. These results demonstrate previously undescribed functions for fibrillarin as an essential component of translocatable viral RNPs and may have implications for other plant and animal viruses that interact with the nucleolus.

    Original languageEnglish
    Pages (from-to)11115-20
    Number of pages6
    JournalProceedings of the National Academy of Sciences of the United States of America
    Volume104
    Issue number26
    DOIs
    Publication statusPublished - 2007

    Fingerprint

    Plant Viruses
    Virus Diseases
    Nuclear Proteins
    Ribonucleoproteins
    Viruses
    Proteins
    Virion
    Gene Silencing
    Protein Transport
    Ribonucleases
    Life Cycle Stages
    Cell Movement
    Cytoplasm
    fibrillarin
    RNA
    Infection

    Cite this

    Kim, Sang Hyon ; Macfarlane, Stuart ; Kalinina, Natalia O. ; Rakitina, Daria V. ; Ryabov, Eugene V. ; Gillespie, Trudi ; Haupt, Sophie ; Brown, John W. S. ; Taliansky, Michael. / Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection. In: Proceedings of the National Academy of Sciences of the United States of America. 2007 ; Vol. 104, No. 26. pp. 11115-20.
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    title = "Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection",
    abstract = "The nucleolus and specific nucleolar proteins are involved in the life cycles of some plant and animal viruses, but the functions of these proteins and of nucleolar trafficking in virus infections are largely unknown. The ORF3 protein of the plant virus, groundnut rosette virus (an umbravirus), has been shown to cycle through the nucleus, passing through Cajal bodies to the nucleolus and then exiting back into the cytoplasm. This journey is absolutely required for the formation of viral ribonucleoprotein particles (RNPs) that, themselves, are essential for the spread of the virus to noninoculated leaves of the shoot tip. Here, we show that these processes rely on the interaction of the ORF3 protein with fibrillarin, a major nucleolar protein. Silencing of the fibrillarin gene prevents long-distance movement of groundnut rosette virus but does not affect viral replication or cell-to-cell movement. Repressing fibrillarin production also localizes the ORF3 protein to multiple Cajal body-like aggregates that fail to fuse with the nucleolus. Umbraviral ORF3 protein and fibrillarin interact in vitro and, when mixed with umbravirus RNA, form an RNP complex. This complex has a filamentous structure with some regular helical features, resembling the RNP complex formed in vivo during umbravirus infection. The filaments formed in vitro are infectious when inoculated to plants, and their infectivity is resistant to RNase. These results demonstrate previously undescribed functions for fibrillarin as an essential component of translocatable viral RNPs and may have implications for other plant and animal viruses that interact with the nucleolus.",
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    Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection. / Kim, Sang Hyon; Macfarlane, Stuart; Kalinina, Natalia O.; Rakitina, Daria V.; Ryabov, Eugene V.; Gillespie, Trudi; Haupt, Sophie; Brown, John W. S.; Taliansky, Michael.

    In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 104, No. 26, 2007, p. 11115-20.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection

    AU - Kim, Sang Hyon

    AU - Macfarlane, Stuart

    AU - Kalinina, Natalia O.

    AU - Rakitina, Daria V.

    AU - Ryabov, Eugene V.

    AU - Gillespie, Trudi

    AU - Haupt, Sophie

    AU - Brown, John W. S.

    AU - Taliansky, Michael

    PY - 2007

    Y1 - 2007

    N2 - The nucleolus and specific nucleolar proteins are involved in the life cycles of some plant and animal viruses, but the functions of these proteins and of nucleolar trafficking in virus infections are largely unknown. The ORF3 protein of the plant virus, groundnut rosette virus (an umbravirus), has been shown to cycle through the nucleus, passing through Cajal bodies to the nucleolus and then exiting back into the cytoplasm. This journey is absolutely required for the formation of viral ribonucleoprotein particles (RNPs) that, themselves, are essential for the spread of the virus to noninoculated leaves of the shoot tip. Here, we show that these processes rely on the interaction of the ORF3 protein with fibrillarin, a major nucleolar protein. Silencing of the fibrillarin gene prevents long-distance movement of groundnut rosette virus but does not affect viral replication or cell-to-cell movement. Repressing fibrillarin production also localizes the ORF3 protein to multiple Cajal body-like aggregates that fail to fuse with the nucleolus. Umbraviral ORF3 protein and fibrillarin interact in vitro and, when mixed with umbravirus RNA, form an RNP complex. This complex has a filamentous structure with some regular helical features, resembling the RNP complex formed in vivo during umbravirus infection. The filaments formed in vitro are infectious when inoculated to plants, and their infectivity is resistant to RNase. These results demonstrate previously undescribed functions for fibrillarin as an essential component of translocatable viral RNPs and may have implications for other plant and animal viruses that interact with the nucleolus.

    AB - The nucleolus and specific nucleolar proteins are involved in the life cycles of some plant and animal viruses, but the functions of these proteins and of nucleolar trafficking in virus infections are largely unknown. The ORF3 protein of the plant virus, groundnut rosette virus (an umbravirus), has been shown to cycle through the nucleus, passing through Cajal bodies to the nucleolus and then exiting back into the cytoplasm. This journey is absolutely required for the formation of viral ribonucleoprotein particles (RNPs) that, themselves, are essential for the spread of the virus to noninoculated leaves of the shoot tip. Here, we show that these processes rely on the interaction of the ORF3 protein with fibrillarin, a major nucleolar protein. Silencing of the fibrillarin gene prevents long-distance movement of groundnut rosette virus but does not affect viral replication or cell-to-cell movement. Repressing fibrillarin production also localizes the ORF3 protein to multiple Cajal body-like aggregates that fail to fuse with the nucleolus. Umbraviral ORF3 protein and fibrillarin interact in vitro and, when mixed with umbravirus RNA, form an RNP complex. This complex has a filamentous structure with some regular helical features, resembling the RNP complex formed in vivo during umbravirus infection. The filaments formed in vitro are infectious when inoculated to plants, and their infectivity is resistant to RNase. These results demonstrate previously undescribed functions for fibrillarin as an essential component of translocatable viral RNPs and may have implications for other plant and animal viruses that interact with the nucleolus.

    U2 - 10.1073/pnas.0704632104

    DO - 10.1073/pnas.0704632104

    M3 - Article

    VL - 104

    SP - 11115

    EP - 11120

    JO - Proceedings of the National Academy of Sciences

    JF - Proceedings of the National Academy of Sciences

    SN - 0027-8424

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    ER -