Porcine Reproductive and Respiratory Syndrome Virus Nonstructural Protein 4 Induces Apoptosis Dependent on Its 3C-Like Serine Protease Activity

摘要: Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease in pigs caused by PRRS virus (PRRSV). Although PRRSV infection-induced cell apoptosis has been established, the related viral protein still unknown. Here, we reported that nonstructural 4 (nsp4) was critical inducer. Nsp4 could activate caspase-3, -8, -9. Using truncated constructs without different domains nsp4, demonstrated full-length of nsp4 structure required for its apoptosis-inducing activity. Furthermore, using site-directed mutagenesis to inactivate 3C-like serine protease activity showed nsp4-induced dependent on The ability induce significantly impaired His39, Asp64, Ser118 mutations, suggesting were essential trigger apoptosis. In conclusion, our present work host cells might be partially responsible induced infection. protease-mediated represents first report genus Arterivirus, family Arteriviridae.