title: The host Pex19p plays a role in peroxisomal localization of tombusvirus replication proteins.
abstract: Replication of Tomato bushy stunt virus (TBSV) RNA takes place on the cytosolic membrane surface of peroxisomes in plants and in yeast, a model host. To identify the host proteins involved in assisting the peroxisomal localization of the tombusvirus p33 replication protein, we tested if p33 could bind directly to yeast proteins involved in peroxisomal transport in vitro. This work has led to the demonstration of Pex19p-p33 interaction via pull-down and co-purification experiments. Pex19p was also detected in the tombusvirus replicase after protein cross-linking, suggesting that Pex19p transiently binds to the replicase as could be expected from a transporter. To validate the importance of Pex19p-p33 interaction in TBSV replication in yeast, we re-targeted Pex19p to the mitochondria, which resulted in the re-distribution of a large fraction of p33 to the mitochondria. The expression of the mitochondrial-targeted Pex19p inhibited TBSV RNA accumulation by 2-4-fold in vivo and reduced the in vitro activity of the tombusvirus replicase by 80%. These data support the model that Pex19p is a cellular transporter for localization of p33 replication protein to the host peroxisomal membranes.
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Kunj B
authors.initials: KB
authors.lastname: Pathak
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Sasvari
authors.forename: Peter D
authors.initials: PD
authors.lastname: Nagy
mesh_terms: D001483:Base Sequence; D003432:Cross-Linking Reagents; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005557:Formaldehyde; D054884:Host-Pathogen Interactions; D007425:Intracellular Membranes / Q000378:metabolism / Q000821:virology; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism / Q000821:virology; D008954:Models, Biological; D020675:Peroxisomes / Q000378:metabolism* / Q000821:virology*; D011485:Protein Binding; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000821:virology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017864:Tombusvirus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D014764:Viral Proteins / Q000302:isolation & purification / Q000502:physiology*; D014779:Virus Replication
chemical_list: D003432:Cross-Linking Reagents; D017931:DNA Primers; D004271:DNA, Fungal; D008565:Membrane Proteins; C109779:PEX19 protein, S cerevisiae; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014764:Viral Proteins; D005557:Formaldehyde; D012324:RNA-Dependent RNA Polymerase