RNA Virus Replication Depends on Enrichment of Phosphatidylethanolamine at Replication Sites in Subcellular Membranes
Intracellular membranes are critical for replication of positive-strand RNA viruses. To dissect the roles of various lipids, we have developed an artificial phosphatidylethanolamine (PE) vesicle-based Tomato bushy stunt virus (TBSV) replication assay. We demonstrate that the in vitro assembled viral replicase complexes (VRCs) in artificial PE vesicles can support a complete cycle of replication and asymmetrical RNA synthesis, which is a hallmark of (+)-strand RNA viruses. Vesicles containing ~85% PE and ~15% additional phospholipids are the most efficient, suggesting that TBSV replicates within membrane microdomains enriched for PE. Accordingly, lipidomics analyses show increased PE levels in yeast surrogate host and plant leaves replicating TBSV. In addition, efficient redistribution of PE leads to enrichment of PE at viral replication sites. Expression of the tombusvirus p33 replication protein in the absence of other viral compounds is sufficient to promote intracellular redistribution of PE. Increased PE level due to deletion of PE methyltransferase in yeast enhances replication of TBSV and other viruses, suggesting that abundant PE in subcellular membranes has a proviral function. In summary, various (+)RNA viruses might subvert PE to build membrane-bound VRCs for robust replication in PE-enriched membrane microdomains.
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This work was supported by National Science Foundation Grant MCB-1122039 (to P.D.N.). The lipid analyses described in this work were performed at the Kansas Lipidomics Research Center Analytical Laboratory. The Kansas Lipsidomics Research Center was supported by National Science Foundation Grants EPS 0236913, MCB 0920663, DBI 0521587, and DBI 1228622; the Kansas Technology Enterprise Corporation; K-IDeA Networks of Biomedical Research Excellence of the National Institutes of Health Grant (P20GM103418); and Kansas State University.
Xu, Kai and Nagy, Peter D., "RNA Virus Replication Depends on Enrichment of Phosphatidylethanolamine at Replication Sites in Subcellular Membranes" (2015). Plant Pathology Faculty Publications. 35.