Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-36919 - MCMV infection of cultured mouse cells induces expression of miR-7a
Released on 30 June 2012, last updated on 17 July 2012
One goal of viral infection is to reprogram the host cell to optimize viral replication. As part of this process, viral miRNAs may compete for components of the miRNA/siRNA pathway as well as regulate cellular targets. Mouse Cytomegalovirus has been described to generate large numbers of viral miRNAs during lytic infection and was therefore used to analyze the impact of viral miRNAs on the host cell small RNA system as well as to check for sorting of viral small RNAs into specific Ago-proteins. Deep sequencing analysis of MCMV infected cells revealed that viral miRNAs represent only app. 13% of all detected miRNAs. All previously described MCMV miRNAs with the exception of miR-m88-1* were confirmed and for the MCMV miR-m01-1 hairpin an additional miRNA, designated miR-m01-1-3p, was found. Its presence was confirmed by qPCR and Northern Blot. Deep sequencing after RISC IP with antibodies specific for either Ago1 or Ago2 showed that all MCMV miRNAs are loaded into both RISC complexes. The ratio of MCMV to mouse miRNAs was not increased after immunoprecipitation of Ago-proteins. Viral miRNAs therefore do not overwhelm the host miRNA processing system nor are they preferentially incorporated into RISC. We found that 3 mouse miRNAs showed an altered expression due to MCMV infection. Down-regulation of miR-27a, as previously described, could be confirmed. In addition, miR-26a was down-regulated and an up-regulation of miR-7a dependent on viral protein expression could be observed. Examination of small RNA expression in uninfected vs. infected cells, immunoprecipitation + sequencing of Ago1 and Ago2 loaded small RNAs in infected cells
RNA-seq of non coding RNA
Klaus Förstemann <email@example.com>, Alexandra Dittmer