2. Academic Validation
  3. PSMB4 Degrades the Porcine Reproductive and Respiratory Syndrome Virus Nsp1α Protein via the Autolysosome Pathway and Induces the Production of Type I Interferon

PSMB4 Degrades the Porcine Reproductive and Respiratory Syndrome Virus Nsp1α Protein via the Autolysosome Pathway and Induces the Production of Type I Interferon

  • J Virol. 2023 Mar 21;e0026423. doi: 10.1128/jvi.00264-23.
Heyou Yi 1 2 3,  Qiumei Wang 1,  Lechen Lu 1,  Ruirui Ye 1,  Ermin Xie 1,  Zhiqing Yu 4,  Yankuo Sun 1 2 3,  Yao Chen 5,  Mengkai Cai 6,  Yingwu Qiu 1,  Qianwen Wu 1,  Jie Peng 1,  Heng Wang 1 2 3,  Guihong Zhang 1 2 3
Affiliations

Affiliations

  • 1 Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
  • 2 Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, China.
  • 3 National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, China.
  • 4 Key Laboratory of Veterinary Bioproduction and Chemical Medicine of the Ministry of Agriculture, Engineering and Technology Research Center for Beijing Veterinary Peptide Vaccine Design and Preparation, Zhongmu Institutes of China Animal Husbandry Industry Co. Ltd., Beijing, China.
  • 5 School of Life Science and Engineering, Foshan University, Foshan, China.
  • 6 Guangdong Meizhou Vocational and Technical College, Meizhou, China.
PMID: 36943051 DOI: 10.1128/jvi.00264-23
Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) causes respiratory disease in pigs of all ages and reproductive failure in sows, resulting in great economic losses to the swine industry. In this work, we identified the interaction between PSMB4 and PRRSV Nsp1α by yeast two-hybrid screening. The PSMB4-Nsp1α interaction was further confirmed by coimmunoprecipitation, glutathione S-transferase (GST) pulldown, and laser confocal experiments. The PCPα domain (Amino acids 66 to 166) of Nsp1α and the C-terminal domain (Amino acids 250 to 264) of PSMB4 were shown to be critical for the PSMB4-Nsp1α interaction. PSMB4 overexpression reduced PRRSV replication, whereas PSMB4 knockdown elicited opposing effects. Mechanistically, PSMB4 targeted K169 in Nsp1α for K63-linked ubiquitination and targeted Nsp1α for autolysosomal degradation by interacting with LC3 to enhance the activation of the lysosomal pathway. Meanwhile, we found that PSMB4 activated the NF-κB signaling pathway to produce type I interferons by downregulating the expression of IκBα and p-IκBα. In conclusion, our data revealed a new mechanism of PSMB4-mediated restriction of PRRSV replication, whereby PSMB4 was found to induce Nsp1α degradation and type I interferon expression, in order to impede the replication of PRRSV. IMPORTANCE In the swine industry, PRRSV is a continuous threat, and the current vaccines are not effective enough to block it. This study determined that PSMB4 plays an Antiviral role against PRRSV. PSMB4 was found to interact with PRRSV Nsp1α, mediate K63-linked ubiquitination of Nsp1α at K169, and thus trigger its degradation via the lysosomal pathway. Additionally, PSMB4 activated the NF-κB signaling pathway to produce type I interferons by downregulating the expression of IκBα and p-IκBα. This study extends our understanding of the Proteasome subunit PSMB4 against PRRSV replication and will contribute to the development of new Antiviral strategies.

Keywords

PRRSV; autolysosome; host protein; replication; ubiquitin; ubiquitination.

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