Project description:Virus infections induce cellular gene up and down regulation, and these changes often provide clues to cellular pathways utilized by viruses. We used microarrays to examine the transcriptional responses of cultured Drosophila S2 cells to Flock House virus (FHV) replicon induction.
Project description:Virus infections induce cellular gene up and down regulation, and these changes often provide clues to cellular pathways utilized by viruses. We used microarrays to examine the transcriptional responses of cultured Drosophila S2 cells to infection with Flock House virus (FHV).
2009-04-01 | GSE15466 | GEO
Project description:Flock House virus puff particle
Project description:Virus infections induce cellular gene up and down regulation, and these changes often provide clues to cellular pathways utilized by viruses. We used microarrays to examine the transcriptional responses of cultured Drosophila S2 cells to infection with Flock House virus (FHV). Experiment Overall Design: Cultured S2 cells were infected with FHV at an MOI of 10 and we measured global transcript levels at 12 h after infection compared to control mock infected cells using Affymetrix Drosophila Genome 1.0 microarray chips.
Project description:Virus infections induce cellular gene up and down regulation, and these changes often provide clues to cellular pathways utilized by viruses. We used microarrays to examine the transcriptional responses of cultured Drosophila S2 cells to Flock House virus (FHV) replicon induction. Experiment Overall Design: Cultured S2 cells stably transfected with either a control replicon (pS2F1fs) or an FHV RNA1 replicon (pS2F1) were induced with 1 mM copper and we measured global transcript levels at 18 h after induction using Affymetrix Drosophila Genome 2.0 microarray chips.
Project description:The larger segment (RNA 1) of the bipartite, positive-sense RNA genome of the nodavirus flock house virus encodes the viral RNA-dependent RNA polymerase. Two nonstructural viral proteins are made during the self-directed replication of this RNA: protein A (110 kDa), the translation product of RNA 1 itself, and protein B (11 kDa), the translation product of a subgenomic RNA (RNA 3) that is produced from RNA 1 during replication. To examine the roles of these proteins in RNA replication, specialized T7 transcription plasmids that contained wild-type or mutant copies of flock house virus RNA 1 cDNA were constructed and used in cells infected with the vaccinia virus-T7 RNA polymerase recombinant to make full-length transcripts that directed their own replication. Sequences in the primary transcripts that extended beyond the ends of the authentic RNA 1 sequence inhibited self-directed RNA replication, but plasmids that were constructed to minimize these terminal extensions produced primary transcripts that replicated as abundantly as authentic RNA 1. Truncation or mutation of the open reading frame for protein A eliminated self-directed replication, although the mutant RNA 1 remained a competent template for replication by wild-type protein A supplied in trans. These results showed that protein A was essential for RNA replication and that the process was not inseparably coupled to complete translation of the template. In contrast, protein B could be eliminated without inhibiting replication by mutations that disrupted the second of the two overlapping open reading frames on RNA 3. Furthermore, a mutant of RNA 1 in which the first nucleotide of the RNA 3 region was changed from G to U replicated at levels as high as those of the wild type without making either RNA 3 or protein B. However, diminishing replication levels were observed during subsequent replicative passages of RNA from both the mutants that could not make protein B. Roles for this protein that could account for the subtle phenotype of these mutants are discussed.
