(A) HSV-1 infection induces PARP5a phosphorylation via ERK and promotes its expression and translocation to the nucleus by interacting with ICP0, which results in proteasome-dependent degradation of PARP5a, enhancing HSV replication. (B) PARP1 or PARP5 binds and ADP-ribosylates EBNA1, which inhibits EBV replication. (C) PARP7 mono-ADP-ribosylates TBK1 and down-regulates type I interferon response to viral infection; Upon SINV infection, PARP7 binds viral RNA and EXOSC5 (an exosome component) for RNA degradation. (D) IFN-induced overexpression of STAT1 up-regulates of PARP9 and DTX3L. In turn, PARP9/DTX3L complex binds and promotes STAT1 phosphorylation, nuclear localization, and increases ISGs levels, and triggers degradation of EMCV 3C proteases; (E) PARP9 recognizes viral dsRNA from RNA viruses and employs PI3K/AKT3 pathway to phosphorylate IRF3 and IRF7 for inducing type I IFN, which inhibits the RNA virus infection. Created with BioRender.com.