Identification of an RNA-silencing suppressor in the genome of Grapevine virus A
Zhou, Z. Sh. and Dell'Orco, M. and Saldarelli, P. and Turturo, C. and Minafra, A. and Martelli, G. P.,, 87, 2387-2395 (2006),
doi = https://doi.org/10.1099/vir.0.81893-0,
publicationName = Microbiology Society,
issn = 0022-1317,
abstract= Higher plants use post-transcriptional gene silencing (PTGS), an RNA-degradation system, as a defence mechanism against viral infections. To counteract this, plant viruses encode and express PTGS suppressor proteins. Four of the five proteins encoded by the Grapevine virus A (GVA) genome were screened using a green fluorescent protein (GFP)-based transient expression assay, and the expression product of ORF5 (protein p10) was identified as a suppressor of silencing. ORF5 p10 suppressed local and systemic silencing induced by a transiently expressed single-stranded sense RNA. This protein was active towards both a transgene and exogenous GFP mRNAs. Ectopic expression of GVA-ORF5 by a Potato virus X vector enhanced symptom severity. The findings that p10 markedly reduces the levels of small interfering RNAs (siRNAs) and that the recombinant protein is able to bind single-stranded and double-stranded forms of siRNAs and microRNAs, suggest the existence of a potential mechanism of suppression based on RNA sequestering.,
language=,
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