@article{mbs:/content/journal/jgv/10.1099/vir.0.83253-0, author = "Kroese, Michiel V. and Zevenhoven-Dobbe, Jessika C. and Bos-de Ruijter, Judy N. A. and Peeters, Ben P. H. and Meulenberg, Janneke J. M. and Cornelissen, Lisette A. H. M. and Snijder, Eric J.", title = "The nsp1α and nsp1β papain-like autoproteinases are essential for porcine reproductive and respiratory syndrome virus RNA synthesis", journal= "Journal of General Virology", year = "2008", volume = "89", number = "2", pages = "494-499", doi = "https://doi.org/10.1099/vir.0.83253-0", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.83253-0", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "The two N-terminal cleavage products, nsp1α and nsp1β, of the replicase polyproteins of porcine reproductive and respiratory syndrome virus (PRRSV) each contain a papain-like autoproteinase domain, which have been named PCPα and PCPβ, respectively. To assess their role in the PRRSV life cycle, substitutions and deletions of the presumed catalytic cysteine and histidine residues of PCPα and PCPβ were introduced into a PRRSV infectious cDNA clone. Mutations that inactivated PCPα activity completely blocked subgenomic mRNA synthesis, but did not affect genome replication. In contrast, mutants in which PCPβ activity was blocked proved to be non-viable and no sign of viral RNA synthesis could be detected, indicating that the correct processing of the nsp1β/nsp2 cleavage site is essential for PRRSV genome replication. In conclusion, the data presented here show that a productive PRRSV life cycle depends on the correct processing of both the nsp1α/nsp1β and nsp1β/nsp2 junctions.", }