Location: Virus and Prion Research
Project Number: 5030-32000-108-24-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 17, 2013
End Date: Oct 1, 2014
Determine the arrangement and architecture of a newly described viral structural component of porcine reproductive and respiratory syndrome virus (PRRSV), nonstructural protein 2 (nsp2) of the replicase polyprotein, through the use of different viral strains, viral mutants, artificially synthesized nsp2 protein and membranes, nsp2 proteinase cleavage sites and sugar-modified residues as well as cell-derived lysates containing unidentified protease(s).
The recent discovery of the nsp2 protein on the outside of the virion of porcine reproductive and respiratory syndrome virus (PRRSV) suggests that this protein is involved in initial contact with the host cell, soon after infection. This protein is extremely large (129 kDa), making up 30% of the replicase polyprotein, and has a possible signal peptide, a protease domain, a long middle region prone to mutation, 3-5 predicted transmembrane regions, followed by a C-terminal extension. In order to decipher which regions of the protein are externally located (extravirion) and which are positioned inside the virus (intravirion), we will identify the orientation of nsp2 with respect to the virion, possible sites that are posttranslationally modified by sugar residues, and delineate the regions that are protected by the lipid bilayer. Such core knowledge is needed to understand what regions could be engineered to produce a more efficacious vaccine.