F-box-like domain in the polerovirus protein P0 is required for silencing suppressor function

Maghsoud Pazhouhandeh, Monika Dieterle, Katia Marrocco, Esther Lechner, Bassam Berry, Véronique Brault, Odile Hemmer, Thomas Kretsch, Kenneth E. Richards, Pascal Genschik, Véronique Ziegler-Graff*

*Corresponding author for this work

    Research output: Contribution to journalArticleResearchpeer-review

    233 Citations (Scopus)


    Plants employ small RNA-mediated posttranscriptional gene silencing as a virus defense mechanism. In response, plant viruses encode proteins that can suppress RNA silencing, but the mode of action of most such proteins is poorly understood. Here, we show that the silencing suppressor protein P0 of two Arabidopsis-infecting poleroviruses interacts by means of a conserved minimal F-box motif with Arabidopsis thaliana orthologs of S-phase kinase-related protein 1 (SKP1), a component of the SCF family of ubiquitin E3 ligases. Point mutations in the F-box-like motif abolished the P0-SKP1 ortholog interaction, diminished virus pathogenicity, and inhibited the silencing suppressor activity of P0. Knockdown of expression of a SKP1 ortholog in Nicotiana benthamiana rendered the plants resistant to polerovirus infection. Together, the results support a model in which P0 acts as an F-box protein that targets an essential component of the host posttranscriptional gene silencing machinery.

    Original languageEnglish
    Pages (from-to)1994-1999
    Number of pages6
    JournalProceedings of the National Academy of Sciences of the United States of America
    Issue number6
    Publication statusPublished - 15 Feb 2006


    • E3 ubiquitin ligase
    • RNA silencing
    • Viral pathogenicity
    • Viral suppressor


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