PMID- 36815765 OWN - NLM STAT- Publisher LR - 20240216 IS - 2165-0497 (Electronic) IS - 2165-0497 (Linking) VI - 11 IP - 2 DP - 2023 Feb 23 TI - Porcine Reproductive and Respiratory Syndrome Virus nsp5 Induces Incomplete Autophagy by Impairing the Interaction of STX17 and SNAP29. PG - e0438622 LID - 10.1128/spectrum.04386-22 [doi] LID - e04386-22 AB - Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically important pathogen that has devastated the worldwide swine industry for over 30 years. Autophagy is an evolutionarily conserved intracellular lysosomal degradation pathway, and previous studies have documented that PRRSV infection prompts autophagosome accumulation. However, whether PRRSV induces complete or incomplete autophagy remains controversial. Here, we demonstrated that overexpression of PRRSV nonstructural protein 5 (nsp5) induced the accumulation of autophagosomes, and a similar scenario was observed in PRRSV-infected cells. Moreover, both PRRSV infection and nsp5 overexpression activated incomplete autophagy, as evidenced by the blockage of autophagosome-lysosome fusion. Mechanistically, nsp5 overexpression, as well as PRRSV infection, inhibited the interaction of syntaxin 17 (STX17) with synaptosomal-associated protein 29 (SNAP29), two SNARE proteins that mediate autophagosome fusion with lysosomes, to impair the formation of autolysosomes. We further confirmed that nsp5 interacted with STX17, rather than SANP29, and the interacting domains of STX17 were the N-terminal motif and SNARE motif. Taken together, the findings of our study suggest a mechanism by which PRRSV induces incomplete autophagy by blocking autophagosome degradation and provide insights into the development of new therapeutics to combat PRRSV infection. IMPORTANCE A substantial number of viruses have been demonstrated to utilize or hijack autophagy to benefit their replication. In the case of porcine reproductive and respiratory syndrome virus (PRRSV), previous studies have demonstrated the proviral effects of autophagy on PRRSV proliferation. Thus, an investigation of the mechanism by which PRRSV regulates the autophagy processes can provide new insight into viral pathogenesis. Autophagic flux is a dynamic process that consists of autophagosome formation and subsequent lysosomal degradation. However, the exact effect of PRRSV infection on the autophagic flux remains disputed. In this study, we demonstrated that PRRSV infection, as well as PRRSV nsp5 overexpression, inhibited the interaction of STX17 with SNAP29 to impair the fusion of autophagosomes with lysosomes, thereby blocking autophagic flux. This information will help us to understand PRRSV-host interactions and unravel new targets for PRRS prevention and control. FAU - Zhou, Yanrong AU - Zhou Y AD - State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. AD - Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. FAU - Li, Yang AU - Li Y AD - State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. AD - Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. FAU - Tao, Ran AU - Tao R AD - State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. AD - Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. FAU - Li, Jia AU - Li J AD - State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. AD - Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. FAU - Fang, Liurong AU - Fang L AUID- ORCID: 0000-0003-1406-6409 AD - State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. AD - Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. FAU - Xiao, Shaobo AU - Xiao S AUID- ORCID: 0000-0003-0023-9188 AD - State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. AD - Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China. LA - eng PT - Journal Article DEP - 20230223 PL - United States TA - Microbiol Spectr JT - Microbiology spectrum JID - 101634614 SB - IM PMC - PMC10101144 OTO - NOTNLM OT - autophagy OT - nonstructural protein 5 OT - porcine reproductive and respiratory syndrome virus OT - synaptosomal-associated protein 29 OT - syntaxin 17 COIS- The authors declare no conflict of interest. EDAT- 2023/02/24 06:00 MHDA- 2023/02/24 06:00 PMCR- 2023/02/23 CRDT- 2023/02/23 09:03 PHST- 2023/02/23 09:03 [entrez] PHST- 2023/02/24 06:00 [pubmed] PHST- 2023/02/24 06:00 [medline] PHST- 2023/02/23 00:00 [pmc-release] AID - 04386-22 [pii] AID - spectrum.04386-22 [pii] AID - 10.1128/spectrum.04386-22 [doi] PST - aheadofprint SO - Microbiol Spectr. 2023 Feb 23;11(2):e0438622. doi: 10.1128/spectrum.04386-22.