Cullin 3-mediated ubiquitination restricts enterovirus D68 replication and is counteracted by viral protease 3C
- J Virol. 2025 Jun 17;99(6):e0035425. doi: 10.1128/jvi.00354-25.
- 1. Department of Pathology, The First Bethune Hospital of Jilin University, Changchun, China.
- 2. Institute of Virology and AIDS Research, First Hospital, Jilin University, Changchun, China.
- 3. Key Laboratory of Pathobiology, Ministry of Education, Nanomedicine and Translational Research Center, China-Japan Union Hospital of Jilin University, Changchun, China.
- 4. Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
- 5. Cancer Center, Zhejiang University, Hangzhou, China.
- 6. Cancer Center Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Institute of Translational Medicine, First Hospital, Jilin University, Changchun, China.
- # Contributed equally.
Enterovirus D68 (EV-D68) has emerged as a significant threat to public health because of its association with respiratory illnesses and neurological complications, including acute flaccid myelitis. However, the molecular mechanisms underlying EV-D68 replication and pathogenesis remain unclear. Here, we revealed a novel interaction between EV-D68 and the host Cullin-RING E3 Ligase system, specifically Cullin 3, which was reported to restrict viral replication. We initially demonstrated that Proteasome inhibition enhanced EV-D68 replication, suggesting an important role for the ubiquitin-proteasome system in viral restriction. Cullin 3 was further identified as a key factor that inhibits EV-D68 replication, and the downregulation of its expression increased viral titers. Mechanistically, Cullin 3 was observed to target the viral capsid protein VP1 for ubiquitination and degradation. However, EV-D68 was determined to utilize its protease 3C to cleave Cullin 3 at the Q681 residue, thereby inhibiting E3 Ligase activity and facilitating resistance to Cullin 3-mediated VP1 degradation. This study uncovered a host-virus arms race, wherein the ubiquitin-proteasome system of the host actively targets Viral Proteins for degradation, and viral proteases counteract this defense mechanism. Accordingly, these findings could lead to more effective Antiviral treatments.
Importance: The ubiquitin-proteasome system (UPS) is a critical cellular pathway involved in the regulation of protein stability and has been implicated in the regulation of viral infections. However, its role in EV-D68 Infection has not been extensively explored. Our study proves that the host UPS, through the scaffold protein Cullin 3, can restrict EV-D68 replication, representing a previously unrecognized Antiviral mechanism. Furthermore, we describe a viral strategy used to evade this host defense mechanism comprising Cullin 3 cleavage, which has broad implications for understanding virus-host interactions and could inform the development of novel therapeutic strategies against EV-D68 and Other enteroviruses.