The Seneca Valley virus 3C protease cleaves DCP1A to attenuate its antiviral effects

• DOI: 10.1186/s13567-025-01477-0
• Publication Date: 2025-02-28T08:42:27Z
• Authors: Jingjing Yang; Zijian Li; Ruiyi Ma; Shijie Xie; Dan Wang; Rong Quan; Xuexia Wen; Jiangwei Song
• Keywords: DCP1A; Veterinary medicine; Seneca Valley virus (SVV); SF600-1100; cleavage; 3C protease; 3D

Abstract Seneca Valley virus (SVV), a new member of Picornaviridae, causes idiopathic vesicular symptoms in pregnant sows and acute death in neonatal piglets, considerably damaging the swine industry. The viral protease 3C (3Cpro) cleaves host immune-related molecules to create a favorable environment for viral replication. In this study, we found that mRNA decapping enzyme 1A (DCP1A) is a novel antiviral effector against SVV infection that targets 3D viral RNA-dependent RNA polymerase for OPTN-mediated autophagic degradation. To counteract this effect, SVV 3Cpro targets DCP1A for cleavage at glutamine 343 (Q343), resulting in the cleaved products DCP1A (1–343) and DCP1A (344–580), which lose the ability to restrict SVV replication. In contrast, the 3C cleavage-resistant DCP1A-Q343A mutant exhibited stronger antiviral effects than the wild-type DCP1A. Additionally, the degradation of the viral 3D protein targeted by DCP1A was abolished after its cleavage by SVV 3Cpro. In conclusion, our study demonstrated that SVV 3Cpro is a pivotal ISG antagonist that cleaves DCP1A. These results offer novel insight into how viruses evade host immunity.