Early events in (+)RNA virus replication: Membrane localization of nodaviral RNA during replication complex assembly

Positive-strand RNA viruses represent the largest class of viruses and include many important human, animal, and plant pathogens. All positive-strand RNA viruses replicate in association with cytoplasmic, membrane-associated, mini-organelles called replication complexes. Crucial for replication within these complexes is the localization of viral replication proteins, genomic RNA templates, and host factors required for replication to the particular membrane where these replication complexes form. In order to understand the fundamental aspects of early events in positive-strand RNA virus replication, we utilized the nodavirus flock house virus. We found that FHV genomic template recruitment to the site of replication complex formation is a distinct early step in RNA virus replication that occurs prior to negative-strand RNA synthesis. Additionally, we determined that FHV genomic template recruitment is viral protein-mediated through interaction with conserved RNA recruitment cis-elements. The mechanisms underlying these processes are similar, though not identical, to the recruitment and replication steps previously identified for brome mosaic virus and those that are beginning to be understood for members of the tombusvirus family. Consequently, these findings are likely applicable to studies of viral replication of other positive-strand RNA viruses.