biostudies-literatureZhou PEarmarked Fund for China Agriculture Research SystemNatural Science Foundation of Hubei ProvinceFundamental Research Funds for the Central UniversitiesPostdoctoral Science Foundation of Hubei ProvinceNational Natural Science Foundation of ChinaChina Postdoctoral Science Foundatione0073525https://www.ebi.ac.uk/biostudies/studies/S-EPMC12282148biostudies-literatureUnknown99(7)The E3 ligase membrane-associated RING finger 6 (MARCH6) plays a pivotal role in various cellular processes; however, its role in viral defense remains largely unexplored. In this study, we have elucidated a novel antiviral mechanism of avian MARCH6 against duck Tembusu virus (TMUV), revealing a previously uncharacterized host defense strategy. Notably, MARCH6 expression was significantly upregulated during TMUV infection in several duck cell lines, suggesting a conserved cellular response. Functional analyses revealed that overexpression of MARCH6 effectively suppressed TMUV replication, whereas its knockdown markedly enhanced viral replication. Mechanistically, MARCH6 directly interacts with the viral non-structural protein 5 (NS5), mediating its targeted degradation through an unprecedeJournal of virologyMARCH6 suppresses Tembusu virus replication by targeting viral NS5 protein for TOLLIP-mediated selective autophagic degradation.PMC122821482662023PY005322729892024AFB1252024HBBHCXA0472024M761078324028652025AFB600GZC20230912CARS-41Yang YJin HZhou PXiao YJongkaewwattana AWu WWei JZhou HLuo RfalseMARCH6 suppresses Tembusu virus replication by targeting viral NS5 protein for TOLLIP-mediated selective autophagic degradation.The E3 ligase membrane-associated RING finger 6 (MARCH6) plays a pivotal role in various cellular processes; however, its role in viral defense remains largely unexplored. In this study, we have elucidated a novel antiviral mechanism of avian MARCH6 against duck Tembusu virus (TMUV), revealing a previously uncharacterized host defense strategy. Notably, MARCH6 expression was significantly upregulated during TMUV infection in several duck cell lines, suggesting a conserved cellular response. Functional analyses revealed that overexpression of MARCH6 effectively suppressed TMUV replication, whereas its knockdown markedly enhanced viral replication. Mechanistically, MARCH6 directly interacts with the viral non-structural protein 5 (NS5), mediating its targeted degradation through an unprecede2025-01-01T00:00:00Z2025 Jul2026-03-18T13:55:28.02Z2025-08-21T09:53:03.314ZS-EPMC122821484051191910.1128/jvi.00735-25