The phosphorylation of the N protein could affect PRRSV virulence in vivo

Abstract

A B S T R A C TThe porcine respiratory and reproductive syndrome virus (PRRSV) nucleocapsid (N) protein is a multiphosphorylated protein.It has been proved that the phosphorylation of N protein could regulate the growth ability of PRRSV in Marc-145 cells. However, further investigation is needed to determine whether phosphorylation of the N protein could affect PRRSV virulence in piglets. In this study, we confirmed that the mutations could impair PRRSV replication ability in porcine primary macrophages (PAMs) as they did in Marc-145 cells. The animal experiments suggested that the pathogenicity of the mutated virus (A105-120) was significantly reduced compared with parent strain (XH-GD). Our results suggested that the phosphorylation of the N protein contributes to virus replication and virulence. This study is the first to identify a specific modification involved in PRRSV pathogenicity. Mutation of PTMs sites is also a novel way to attenuate PRRSV virulence. The mutations could be a marker in a vaccine. In conclusion, our study will improve our understanding of the molecular mechanisms of PRRSV pathogenicity.

Ginsenoside Rg1 Suppresses Type 2 PRRSV Infection via NF-κB Signaling Pathway In Vitro, and Provides Partial Protection against HP-PRRSV in Piglet

“…Blood samples of the piglets were collected at 2, 4, 7, 10, 14 dpi to determine viral load and N protein antibody of PRRSV. And, the viral load in tissues, include lung, lymph node and thymus were determined by qRT-PCR as described previously [31]. Since all of the animals in the PRRSV group died at 11 d.p.i., there was no viremia and tissue viral load analysis on it at 14 or 15 h.p.i.…”

Hyper-phosphorylation of nsp2-related proteins of porcine reproductive and respiratory syndrome virus

“…Phosphorylation by the host GSK3 kinase affects conformational transitions of the MHV N protein and regulates its interaction with the DDX1 helicase to fine-tune the discontinuous transcription of sgRNAs (Wu et al, 2014). Phosphorylation of the N protein of PRRSV has also been reported (Wootton et al, 2002;Yoo et al, 2003;Chen et al, 2018Chen et al, , 2019. Phospho-ablatant mutations on two PRRSV N protein phosphorylation sites attenuated viral replication capability both in vitro and in vivo (Chen et al, 2018(Chen et al, , 2019.…”

“…Phosphorylation of the N protein of PRRSV has also been reported (Wootton et al, 2002;Yoo et al, 2003;Chen et al, 2018Chen et al, , 2019. Phospho-ablatant mutations on two PRRSV N protein phosphorylation sites attenuated viral replication capability both in vitro and in vivo (Chen et al, 2018(Chen et al, , 2019. However, specific biological roles of PRRSV N protein phosphorylation remain largely unclear.…”

The Novel Insight of SARS-CoV-2 Molecular Biology and Pathogenesis and Therapeutic Options

“…N protein functions in attaching and assembling the viral RNA genome to a long helical nucleocapsid structure or matrix of the ribonucleoprotein (Kumar et al, 2020); however, it is remarkably sensitive to proteases (Macnaughton et al, 1978). This protein is phosphorylated in multiple specific positions in various coronaviruses, which may alter functions such as distinguishing nonviral and viral RNA impaired binding of the monoclonal antibody to the virus surface as well as virus maturation and assembling (Kuo et al, 2016;Grunewald et al, 2018;Chen et al, 2019). However, the reason behind phosphorylation has remained uncertain.…”