Peanut Clump Virus RNA-1-Encoded P15 Regulates Viral RNA Accumulation but Is Not Abundant at Viral RNA Replication Sites
AUTOR(ES)
Dunoyer, Patrice
FONTE
American Society for Microbiology
RESUMO
RNA-1 of peanut clump pecluvirus (PCV) encodes N-terminally overlapping proteins which contain helicase-like (P131) and polymerase-like (P191) domains and is able to replicate in the absence of RNA-2 in protoplasts of tobacco BY-2 cells. RNA-1 also encodes P15, which is expressed via a subgenomic RNA. To investigate the role of P15, we analyzed RNA accumulation in tobacco BY-2 protoplasts inoculated with RNA-1 containing mutations in P15. For all the mutants, the amount of progeny RNA-1 produced was significantly lower than that obtained for wild-type RNA-1. If RNA-2 was included in the inoculum, the accumulation of both progeny RNAs was diminished, but near-normal yields of both could be recovered if the inoculum was supplemented with a small, chimeric viral replicon expressing P15, demonstrating that P15 has an effect on viral RNA accumulation. To further analyze the role of P15, transcripts were produced expressing P15 fused to enhanced green fluorescent protein (EGFP). Following inoculation to protoplasts, epifluorescence microscopy revealed that P15 accumulated as spots around the nucleus and in the cytoplasm. Intracellular sites of viral RNA synthesis were visualized by laser scanning confocal microscopy of infected protoplasts labeled with 5-bromouridine 5′-triphosphate (BrUTP). BrUTP labeling also occured in spots distributed within the cytoplasm and around the nucleus. However, the BrUTP-labeled RNA and EGFP/P15 very rarely colocalized, suggesting that P15 does not act primarily at sites of viral replication but intervenes indirectly to control viral accumulation levels.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=115140Documentos Relacionados
- Nuclear Export of mRNA by TAP/NXF1 Requires Two Nucleoporin-Binding Sites but Not p15
- Cleavage of p15 protein in vitro by human immunodeficiency virus type 1 protease is RNA dependent.
- The Valine Anticodon and Valylatability of Peanut Clump Virus RNAs Are Not Essential but Provide a Modest Competitive Advantage in Plants†
- Rotavirus RNA replication: VP2, but not VP6, is necessary for viral replicase activity.
- Brome mosaic virus RNA replication protein 1a dramatically increases in vivo stability but not translation of viral genomic RNA3