Complementary transcriptomic, lipidomic, and targeted functional genetic analyses in cultured Drosophila cells highlight the role of glycerophospholipid metabolism in Flock House virus RNA replication.
BACKGROUND
Cellular membranes are crucial host components utilized by positive-strand RNA viruses for replication of their genomes. Published studies have suggested that the synthesis and distribution of membrane lipids are particularly important for the assembly and function of positive-strand RNA virus replication complexes. However, the impact of specific lipid metabolism pathways in this process have not been well defined, nor have potential changes in lipid expression associated with positive-strand RNA virus replication been examined in detail.


RESULTS
In this study we used parallel and complementary global and targeted approaches to examine the impact of lipid metabolism on the replication of the well-studied model alphanodavirus Flock House virus (FHV). We found that FHV RNA replication in cultured Drosophila S2 cells stimulated the transcriptional upregulation of several lipid metabolism genes, and was also associated with increased phosphatidylcholine accumulation with preferential increases in lipid molecules with longer and unsaturated acyl chains. Furthermore, targeted RNA interference-mediated downregulation of candidate glycerophospholipid metabolism genes revealed a functional role of several genes in virus replication. In particular, we found that downregulation of Cct1 or Cct2, which encode essential enzymes for phosphatidylcholine biosynthesis, suppressed FHV RNA replication.


CONCLUSIONS
These results indicate that glycerophospholipid metabolism, and in particular phosphatidylcholine biosynthesis, plays an important role in FHV RNA replication. Furthermore, they provide a framework in which to further explore the impact of specific steps in lipid metabolism on FHV replication, and potentially identify novel cellular targets for the development of drugs to inhibit positive-strand RNA viruses.
Departments of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
Kathryn M
KM
Castorena
Kenneth A
KA
Stapleford
David J
DJ
Miller
D000818:Animals; D002478:Cells, Cultured; D019916:Choline-Phosphate Cytidylyltransferase / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism / Q000821:virology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D017344:Genes, Insect; D016679:Genome, Viral; D020404:Glycerophospholipids / Q000378:metabolism*; D007304:Insect Viruses / Q000235:genetics* / Q000502:physiology; D050356:Lipid Metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010713:Phosphatidylcholines / Q000096:biosynthesis; D034622:RNA Interference; D012328:RNA Viruses / Q000235:genetics* / Q000502:physiology; D012330:RNA, Double-Stranded / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014779:Virus Replication
D029721:Drosophila Proteins; D020404:Glycerophospholipids; D010713:Phosphatidylcholines; D012330:RNA, Double-Stranded; D012367:RNA, Viral; C481021:Cct1protein, Drosophila; D019916:Choline-Phosphate Cytidylyltransferase