PARP14 is pro- and anti-viral host factor that promotes IFN production and affects the replication of multiple viruses.

The antiviral response is largely regulated by post-translation modifications (PTM), including ADP-ribosylation. PARP14 is an ADP-ribosyltransferase that is upregulated by interferon and is under positive selection, indicating that it is involved in host-pathogen conflict. However, no anti-viral function has been described for PARP14. Here, we found that PARP14 represses both coronavirus and HSV-1 replication, demonstrating that PARP14 has anti-viral functions. Surprisingly, we also found that PARP14 also has pro-viral functions, as it was critical for the efficient infection of several RNA viruses, including Ebola and Nipah viruses, which have high mortality and are viruses with pandemic potential. These data indicate that PARP14 has both pro- and anti-viral functions and is a potential therapeutic target for highly pathogenic RNA viruses.