Effects of PIAS1 on sumoylation of PRRSV N protein and viral replication

Abstract:

[Objective] Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important pathogens that severely affect pork industry worldwide. As a reversible post-translational modification, sumoylation plays an important role in regulating viral replication. Protein inhibitor of activated STAT1 (PIAS1), as a member of SUMO E3 ligase PIAS family, can promote sumoylation of target protein, which affects the function of target protein and further participates in the transcriptional regulation process. This study was designed to study the mechanism of interaction between PIAS1 and PRRSV N protein, as well as its effect on N protein sumoylation and viral replication, to provide a scientific basis for further understanding the replication regulation and pathogenesis of PRRSV. [Methods] The interaction between PRRSV N protein and PIAS1 was first verified by yeast two-hybrid, Co-IP and confocal immunofluorescence assay. And then increased dose of PIAS1 were exogenously transfected to observe whether PIAS1 could mediate sumoylation of N protein. The effect of PIAS1 on PRRSV replication was investigated by testing the virus titer in cells with increased/reduced PIASI by using lentiviral transduction or RNA interference technology. [Results] PIAS1 could interact with the PRRSV N protein, and both of them predominantly located in the cytoplasm. Exogenous transfection of PIAS1 did not increase the sumoylation level of N protein. However, the overexpression of PIAS1 could promote PRRSV replication in MARC-145 cells. [Conclusion] PIAS1 has the function of promoting PRRSV replication.