Poliovirus replication: Identification and mechanistic analysis of novel viral-host interactions

Poliovirus (PV), the causative agent of poliomyelitis, is an RNA virus classified as a human enterovirus in the family Picornaviridae. In order to successfully replicate, all RNA viruses are highly dependent on host proteins and membranes. Host proteins aid the virus in various ways, for example, facilitating host cell shut off, genome circularization, protein trafficking and poly(A) tail extension. Host membranes are used to form viral replication complexes. These complexes act as structural scaffolds to increase the local concentration of both viral and host proteins required for RNA replication. To date, a small number of viral-host interactions have been characterized. We hypothesize that in addition to the few host proteins that have been previously characterized, there are additional host factors that play a role in the PV lifecycle that have yet to be described. Discovery and exploration of novel cellular proteins that are usurped for use during the viral lifecycle is technically challenging. Therefore, we set out to create an efficient, biologically relevant method to identify additional host proteins and examine their function in the PV lifecycle. In this work, we generated recombinant PV containing a strep-tag within the non-structural viral proteins. These viruses were used as a tool to identify novel viral-host interactions under biological conditions. We combined physical interaction maps with genetic and functional assays to uncover how enteroviruses hijack cellular machinery. Our study provides mechanistic insight into how specific interactions between viral proteins and lipid membrane trafficking and signaling components allow the formation of virally induced replication organelles during infection.