Journal of Plant Pathology (2005) 87, 281-282

M. Russo, B. Navarro, V. Pantaleo and L. Rubino (2005)
Cytological analysis of Saccharomyces cerevisiae cells supporting cymbidium ringspot virus defective interfering RNA replication
Journal of Plant Pathology 87 (4), 281-282
XII Meeting, Italian Society for Plant Pathology, Reggio Calabria, 29/9 - 1/10, 2005
Abstract: Positive-strand RNA [(+)RNA] viruses replication takes place in association with host cell membranes, but different viruses recruit diverse intracellular membranes for the assembly of their replication complexes. The study of targeting signals of viral proteins interacting with host cell membranes and of the formation, maintenance and mode of action of the viral replication complex is important for the comprehension of a virus life cycle, also in view of the possible development of an efficient therapy. The use of simple viruses, like tombusviruses, in a genetically characterized host like the yeast Saccharomyces cerevisiae, constitutes a valuable model system to study (+)RNA virus-host cell interactions. In this system the replicase proteins p33 and p92 of Cymbidium ringspot virus (CymRSV) supported the replication of defective interfering (DI) RNA. Three yeast strains were used that differ in the biogenesis of peroxisomes, i.e. the organelles that supply the membranous vesicular environment in which CymRSV RNA replication takes place in infected plant cells. Replication occurred only in yeast cells containing either well-developed or immature peroxisomes, but not in mutant cells where peroxisome biogenesis is impaired. Double-label immunofluorescence showed that both p33 and p92 proteins localized to peroxisomes, independently of one another. It is suggested that these proteins move initially from the cytosol to the endoplasmic reticulum, then to peroxisomes. The expression of p33, but not p92, increased the peroxisome number and induced membrane proliferation. BrUTP incorporation confirmed that newly synthesized DI RNA accumulates predominantly in association with peroxisomes, whereas DI RNA progeny is diffused in the cytoplasm.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Luisa Rubino

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tombusvirus cymbidii