PMID- 36602366 OWN - NLM STAT- MEDLINE DCOM- 20230207 LR - 20230706 IS - 1098-5514 (Electronic) IS - 0022-538X (Print) IS - 0022-538X (Linking) VI - 97 IP - 1 DP - 2023 Jan 31 TI - PSMB1 Inhibits the Replication of Porcine Reproductive and Respiratory Syndrome Virus by Recruiting NBR1 To Degrade Nonstructural Protein 12 by Autophagy. PG - e0166022 LID - 10.1128/jvi.01660-22 [doi] LID - e01660-22 AB - The nonstructural proteins (Nsps) of porcine reproductive and respiratory syndrome virus (PRRSV) play essential roles in virus replication-a multistep process that requires the participation of host factors. It is of great significance for the development of antiviral drugs to characterize the host proteins that interact with PRRSV Nsps and their functions in PRRSV replication. Here, we determined that proteasome subunit beta type 1 (PSMB1) interacted with viral Nsp12 to inhibit PRRSV replication in target and permissive cells. PSMB1 could be downregulated by PRRSV infection through interaction with the transcription factor EBF1. Proteasome and autophagy inhibitor assays showed that PSMB1 was regulated by the autophagic pathway to degrade Nsp12. Cotransfection of PSMB1 and Nsp12 increased the level of intracellular autophagy; both molecules were colocated in lysosomes. We also found that the selective autophagy cargo receptor protein NBR1 and E3 ubiquitin ligase STUB1 interacted with PSMB1 and Nsp12, respectively, in the autophagic degradation of Nsp12. Furthermore, the degradation of Nsp12 by PSMB1 was mainly dependent on the ubiquitination of Nsp12 at lysine site 130. Our results indicate for the first time that PSMB1 is an anti-PRRSV host protein that inhibits the replication of PRRSV by degradation of Nsp12 through the selective autophagy pathway. IMPORTANCE PRRS is a major threat to the global pig industry and urgently requires an effective and sustainable control strategy. PRRSV Nsps have important roles in viral RNA synthesis, proteinase activity, induction of replication-associated membrane rearrangements, replicative endoribonuclease activity, determination of virulence, and regulation of host immune response. Research associated with PRRSV Nsps can provide vital guidance to modify the PRRSV genome through reverse genetics in the development of vaccines and diagnostics. The function of Nsp12, which generally plays essential roles in virus replication, remains unclear. We demonstrated that PSMB1 interacted with and degraded Nsp12 through an autophagic pathway to inhibit PRRSV replication. Our data confirmed a novel antiviral function of PSMB1 and allowed us to elaborate on the roles of Nsp12 in PRRSV pathogenesis. These findings suggest a valid and highly conserved candidate target for the development of novel therapies and more effective vaccines and demonstrate the complex cross talk between selective autophagy and PRRSV infection. FAU - Li, Liwei AU - Li L AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. AD - Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, People's Republic of China. FAU - Bai, Yuanzhe AU - Bai Y AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. FAU - Zhou, Yanjun AU - Zhou Y AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. FAU - Jiang, Yifeng AU - Jiang Y AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. FAU - Tong, Wu AU - Tong W AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. FAU - Li, Guoxin AU - Li G AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. FAU - Zheng, Haihong AU - Zheng H AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. FAU - Gao, Fei AU - Gao F AUID- ORCID: 0000-0003-2291-8712 AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. AD - Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonose, Yangzhou University, Yangzhou, People's Republic of China. FAU - Tong, Guangzhi AU - Tong G AD - Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. AD - Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonose, Yangzhou University, Yangzhou, People's Republic of China. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20230105 PL - United States TA - J Virol JT - Journal of virology JID - 0113724 RN - 0 (Antiviral Agents) RN - EC 3.4.25.1 (Proteasome Endopeptidase Complex) RN - 0 (Viral Nonstructural Proteins) SB - IM MH - Animals MH - Antiviral Agents MH - *Autophagy MH - Porcine Reproductive and Respiratory Syndrome/immunology/prevention & control/virology MH - *Porcine respiratory and reproductive syndrome virus/physiology MH - Proteasome Endopeptidase Complex/metabolism MH - Swine MH - Ubiquitination MH - *Viral Nonstructural Proteins/metabolism MH - *Virus Replication MH - Host Microbial Interactions/immunology PMC - PMC9888268 OTO - NOTNLM OT - NBR1 OT - Nsp12 OT - PRRSV OT - PSMB1 OT - autophagic degradation COIS- The authors declare no conflict of interest. EDAT- 2023/01/06 06:00 MHDA- 2023/02/03 06:00 PMCR- 2023/07/05 CRDT- 2023/01/05 09:13 PHST- 2023/01/06 06:00 [pubmed] PHST- 2023/02/03 06:00 [medline] PHST- 2023/01/05 09:13 [entrez] PHST- 2023/07/05 00:00 [pmc-release] AID - 01660-22 [pii] AID - jvi.01660-22 [pii] AID - 10.1128/jvi.01660-22 [doi] PST - ppublish SO - J Virol. 2023 Jan 31;97(1):e0166022. doi: 10.1128/jvi.01660-22. Epub 2023 Jan 5.