TY - JOUR
T1 - F-box-like domain in the polerovirus protein P0 is required for silencing suppressor function
AU - Pazhouhandeh, Maghsoud
AU - Dieterle, Monika
AU - Marrocco, Katia
AU - Lechner, Esther
AU - Berry, Bassam
AU - Brault, Véronique
AU - Hemmer, Odile
AU - Kretsch, Thomas
AU - Richards, Kenneth E.
AU - Genschik, Pascal
AU - Ziegler-Graff, Véronique
PY - 2006/2/15
Y1 - 2006/2/15
N2 - 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.
AB - 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.
KW - E3 ubiquitin ligase
KW - RNA silencing
KW - Viral pathogenicity
KW - Viral suppressor
UR - http://www.scopus.com/inward/record.url?scp=32444442141&partnerID=8YFLogxK
U2 - 10.1073/pnas.0510784103
DO - 10.1073/pnas.0510784103
M3 - Article
C2 - 16446454
AN - SCOPUS:32444442141
SN - 0027-8424
VL - 103
SP - 1994
EP - 1999
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 6
ER -