A Novel Motif in the 3′-UTR of PRRSV-2 Is Critical for Viral Multiplication and Contributes to Enhanced Replication Ability of Highly Pathogenic or L1 PRRSV

Viruses

Di Liu¹  Kuan Zhao²  Xinyi Huang²  Fang Yu²  Yongbo Yang²  Xingyang Cui²  Junyao Xiong²  Zhijun Tian²  Tongqing An²  Xuehui Cai²  Qian Wang²  Dongyan Li² 

[1]Institute of Animal Husbandry, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China

[2]State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China

关键词: HP-PRRSV;    3′-UTR;    secondary structure;    motif;    replication;    epidemic;   

DOI  :  10.3390/v14020166

来源: DOAJ

【 摘 要 】

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) with enhanced replication capability emerged in China and has become dominant epidemic strain since 2006. Up to now, the replication-regulated genes of PRRSV have not been fully clarified. Here, by swapping the genes or elements between HP-PRRSV and classical PRRSV based on infectious clones, NSP1, NSP2, NSP7, NSP9 and 3′-UTR are found to contribute to the high replication efficiency of HP-PRRSV. Further study revealed that mutations at positions 117th or 119th in the 3′-UTR are significantly related to replication efficiency, and the nucleotide at position 120th is critical for viral rescue. The motif composed by 117–120th nucleotides was quite conservative within each lineage of PRRSV; mutations in the motif of HP-PRRSV and currently epidemic lineage 1 (L1) PRRSV showed higher synthesis ability of viral negative genomic RNA, suggesting that those mutations were beneficial for viral replication. RNA structure analysis revealed that this motif maybe involved into a pseudoknot in the 3′-UTR. The results discovered a novel motif, 117–120th nucleotide in the 3′-UTR, that is critical for replication of PRRSV-2, and mutations in the motif contribute to the enhanced replicative ability of HP-PRRSV or L1 PRRSV. Our findings will help to understand the molecular basis of PRRSV replication and find the potential factors resulting in an epidemic strain of PRRSV.

【 授权许可】

Unknown