title: Cellular Ubc2/Rad6 E2 ubiquitin-conjugating enzyme facilitates tombusvirus replication in yeast and plants.
abstract: Mono- and multi-ubiquitination alters the functions and subcellular localization of many cellular and viral proteins. Viruses can co-opt or actively manipulate the ubiquitin network to support viral processes or suppress innate immunity. Using yeast (Saccharomyces cerevisiae) model host, we show that the yeast Rad6p (radiation sensitive 6) E2 ubiquitin-conjugating enzyme and its plant ortholog, AtUbc2, interact with two tombusviral replication proteins and these E2 ubiquitin-conjugating enzymes could be co-purified with the tombusvirus replicase. We demonstrate that TBSV RNA replication and the mono- and bi-ubiquitination level of p33 is decreased in rad6Δ yeast. However, plasmid-based expression of AtUbc2p could complement both defects in rad6Δ yeast. Knockdown of UBC2 expression in plants also decreases tombusvirus accumulation and reduces symptom severity, suggesting that Ubc2p is critical for virus replication in plants. We provide evidence that Rad6p is involved in promoting the subversion of Vps23p and Vps4p ESCRT proteins for viral replicase complex assembly.
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA. Electronic address: imura@brs.nihon-u.ac.jp.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Imura
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Molho
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Chingkai
authors.initials: C
authors.lastname: Chuang
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA. Electronic address: pdnagy2@uky.edu.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Nagy
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D005816:Genetic Complementation Test; D054884:Host-Pathogen Interactions; D011485:Protein Binding; D025941:Protein Interaction Mapping; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000821:virology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D017864:Tombusvirus / Q000502:physiology*; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D029681:Arabidopsis Proteins; D029701:Saccharomyces cerevisiae Proteins; D044763:Ubiquitin-Conjugating Enzymes; D012324:RNA-Dependent RNA Polymerase
keywords: AAA+ATPase; Cell-free replication; E2 ubiquitin-conjugating enzyme; ESCRT; Host factor; Plant; Ubiquitin; Virus replication