Abstract 1985 Development of an assay to assess the impact of viral RNA epigenomic modifications on transcription speed and fidelity

Flaviviruses are a family of RNA viruses that are commonly found in arthropods and can be transmitted to both animal and human hosts. A large portion of these flaviviruses are human pathogens, infecting up to 400 million people each year. These include Yellow Fever, Dengue, West Nile, Zika, and Powassan viruses. Transfer between hosts, combined with the high error rate of the RNA-dependent RNA polymerases found in these virus, can drive increased rates of mutation and potentially increase viral pathogenicity. Current evidence indicates viral RNA genomes are modified post-transcriptionally, and that these modifications could affect viral RNA stability and replication. This work explores the effect these epigenetic RNA modifications have on the speed and accuracy of RNA transcription by flavivirus RNA-dependent RNA polymerase (RdRp). To examine the effect RNA modifications have on transcription rate and fidelity, we have designed and developed an in vitro assay, using enzyme purified from expression constructs of the flavivirus NS5 RdRp and model RNA transcription templates containing modifications that have been determined to be present in these viral genomes. Using this system, we are measuring the effects these functional group modifications have on how the flavivirus RNA polymerase reads the modified RNA template. Understanding the impact RNA modifications have on flavivirus RNA synthesis will further illuminate its effect on viral replication and evolution. This work was supported by a Scialog grant to K. Koutmou from the Research Corporation and the Albion College Foundation for Undergraduate Research.