Seneca Valley Virus Induces DHX30 Cleavage to Antagonize Its Antiviral Effects

Seneca Valley virus (SVV) is a new pathogen associated with porcine idiopathic vesicular disease (PIVD) in recent years. However, SVV-host interaction is still unclear. In this study, through LC-MS/MS analysis and coimmunoprecipitation analysis, DHX30 was identified as a 3C^pro-interacting protein. 3C^pro mediated the cleavage of DHX30 at a specific site, which depends on its protease activity. Further study showed that DHX30 was an intrinsic antiviral factor against SVV that was dependent on its helicase activity. DHX30 functioned as a viral-RNA binding protein that inhibited SVV replication at the early stage of viral infection. RIP-seq showed comparatively higher coverage depth at SVV 5'UTR, but the distribution across SVV RNA suggested that the interaction had low specificity. DHX30 expression strongly inhibited double-stranded RNA (dsRNA) production. Interestingly, DHX30 was determined to interact with 3D in an SVV RNA-dependent manner. Thus, DHX30 negatively regulated SVV propagation by blocking viral RNA synthesis, presumably by participating in the viral replication complex. IMPORTANCE DHX30, an RNA helicase, is identified as a 3C^pro-interacting protein regulating Seneca Valley virus (SVV) replication dependent on its helicase activity. DHX30 functioned as a viral-RNA binding protein that inhibited SVV replication at the early stage of virus infection. DHX30 expression strongly inhibited double-stranded RNA (dsRNA) production. In addition, 3C^pro abolished DHX30 antiviral effects by inducing DHX30 cleavage. Thus, DHX30 is an intrinsic antiviral factor that inhibits SVV replication.