title: Inhibition of phospholipid biosynthesis decreases the activity of the tombusvirus replicase and alters the subcellular localization of replication proteins.
abstract: Replication of plus-strand RNA viruses depends on lipids present in cellular membranes. Recent genome-wide screens have revealed that eight phospholipid biosynthesis genes affected the replication of Tomato bushy stunt virus (TBSV) in yeast model host. To test the importance of phospholipids in TBSV replication, we studied one of the identified genes, namely INO2, which forms a heterodimer with Ino4, and is a transcription activator involved in regulation of phospholipid biosynthesis. Deletion of INO2, or double deletion of INO2/INO4, reduced TBSV replication and inhibited the activity of the viral replicase complex. In addition, the stability of the viral replication protein is decreased as well as the localization pattern of the viral protein changed dramatically in ino2∆ino4∆ yeast. Over-expression of Opi1, a repressor of Ino2 and phospholipid biosynthesis, also inhibited TBSV RNA accumulation. In contrast, over-expression of Ino2 stimulated TBSV RNA accumulation. We also observed an inhibitory effect on Flock house virus (FHV) replication and the reduced stability of the FHV replication protein in ino2∆ino4∆ yeast. These data are consistent with the important role of phospholipids in RNA virus replication.
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Monika
authors.initials: M
authors.lastname: Sharma
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Sasvari
authors.forename: Peter D
authors.initials: PD
authors.lastname: Nagy
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D010743:Phospholipids / Q000096:biosynthesis*; D055550:Protein Stability; D021381:Protein Transport; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000821:virology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D017864:Tombusvirus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D010743:Phospholipids; D012324:RNA-Dependent RNA Polymerase; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014764:Viral Proteins; C095723:INO2 protein, S cerevisiae; C063311:INO4 protein, S cerevisiae