Host helicase DHX36 inhibits pseudorabies virus proliferation by unwinding the G-quadruplex in the 3'UTR of IE180.

The balance between proliferation and persistence of pseudorabies virus (PRV) in the host is crucial for its long-term survival. Understanding the mechanisms that regulate viral survival may offer new strategies for disease prevention and control. The immediate-early gene 180 (IE180) is essential for PRV replication, and we previously identified a G-quadruplex (PQS18-1) located in the 3' untranslated region (3'UTR) of IE180 that enhances its expression and promotes viral replication. However, the mechanisms by which this G-quadruplex is unwound and contributes to immune evasion remain unclear. In this study, we identified the host helicase DHX36 as a binding partner of PQS18-1 through RNA pull-down assays. Both in vitro and cellular experiments demonstrated that DHX36 destabilizes the G-quadruplex, thereby suppressing gene expression and regulating PRV replication. Our findings reveal a novel host-virus interaction mechanism involving G-quadruplex structures and helicase activity, which may offer new targets for therapeutic intervention.