UPSC SeminarKristiina Mäkinen
Plant virology, Viikki Plant Science Centre (ViPS), Department of Microbiology, University of Helsinki, Finland
Title: Intracellular coordination of potyviral RNA functions
Host: Johannes Hanson
More information about Kristiina Mäkinen's research:
Abstract of her talk:
Potato virus A (PVA) is a positive-sense single-stranded RNA virus, which belongs to genus Potyvirus. Potyviruses cause significant crop losses worldwide. After amplification in the replication complex, viral RNA may continue to novel rounds of translation and replication. Simultaneously with on-going viral gene expression, part of the replicated potyviral RNA enters the movement and assembly pathways or alternatively, host defense may capture it and deliver it to RNA degradation. Protein complexes consisting of viral and host proteins coordinate tightly these processes. Potyviral proteins helper component – proteinase (HCPro) and viral protein genome-linked (VPg) have several roles in PVA infection. We have found that the host proteins ARGONAUTE 1, VARICOSE and eukaryotic initiation factor (iso)4E are incorporated in to the protein complexes containing HCPro and VPg and they are important pro-viral components of the regulation of PVA RNA functions. To understand the relevance of these host proteins in promoting PVA infection we have generated viruses carrying mutations in HCPro and VPg within the binding-sites of these host proteins. We have thoroughly characterized how the mutant viruses perform at different stages of infection including RNA silencing suppression, formation of PVA-induced RNA granules, viral RNA translation and encapsidation as well as their capacity to move in the host plant. The model of the regulation of PVA RNA functions arising from these results will be presented.