Unfolding of an RNA G-quadruplex motif in the negative strand genome of porcine reproductive and respiratory syndrome virus by host and viral helicases to promote viral replication

  • Nucleic Acids Res. 2023 Sep 22;gkad759. doi: 10.1093/nar/gkad759.
Puxian Fang  1  2 ,  Congbao Xie  1  3  4  5 ,  Ting Pan  1  2 ,  Ting Cheng  1  2 ,  Wei Chen  1  2 ,  Sijin Xia  1  2 ,  Tong Ding  1  2 ,  Junkang Fang  1  3  4  5 ,  Yanrong Zhou  1  2 ,  Liurong Fang  1  2 ,  Dengguo Wei  1  3  4  5 ,  Shaobo Xiao  1  2
Affiliations
  • 1. National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.
  • 2. The Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.
  • 3. Hubei Hongshan Laboratory, and Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan 430070, China.
  • 4. Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Shenzhen 518000, China.
  • 5. Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518000, China.
PMID: 37739415 DOI: 10.1093/nar/gkad759
Abstract

G-quadruplex (G4) is a unique secondary structure formed by guanine-rich nucleic acid sequences. Growing studies reported that the genomes of some viruses harbor G4 structures associated with viral replication, opening up a new field to dissect viral Infection. Porcine reproductive and respiratory syndrome virus (PRRSV), a representative member of Arteriviridae, is an economically significant pathogen that has devastated the swine industry worldwide for over 30 years. In this study, we identified a highly conserved G-rich sequence with parallel-type G4 structure (named PRRSV-G4) in the negative strand genome RNA of PRRSV. Pyridostatin (PDS), a well-known G4-binding ligand, stabilized the PRRSV-G4 structure and inhibited viral replication. By screening the proteins interacting with PRRSV-G4 in PRRSV-infected cells and single-molecule magnetic tweezers analysis, we found that two helicases, host DDX18 and viral nsp10, interact with and efficiently unwound the PRRSV-G4 structure, thereby facilitating viral replication. Using a PRRSV reverse genetics system, we confirmed that recombinant PRRSV with a G4-disruptive mutation exhibited resistance to PDS treatment, thereby displaying higher replication than wild-type PRRSV. Collectively, these results demonstrate that the PRRSV-G4 structure plays a crucial regulatory role in viral replication, and targeting this structure represents a promising strategy for Antiviral therapies.

Products