PLoS Pathogens (Feb 2022)

Poly(ADP-ribose) potentiates ZAP antiviral activity.

  • Guangai Xue,
  • Klaudia Braczyk,
  • Daniel Gonçalves-Carneiro,
  • Daria M Dawidziak,
  • Katarzyna Sanchez,
  • Heley Ong,
  • Yueping Wan,
  • Kaneil K Zadrozny,
  • Barbie K Ganser-Pornillos,
  • Paul D Bieniasz,
  • Owen Pornillos

DOI
https://doi.org/10.1371/journal.ppat.1009202
Journal volume & issue
Vol. 18, no. 2
p. e1009202

Abstract

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Zinc-finger antiviral protein (ZAP), also known as poly(ADP-ribose) polymerase 13 (PARP13), is an antiviral factor that selectively targets viral RNA for degradation. ZAP is active against both DNA and RNA viruses, including important human pathogens such as hepatitis B virus and type 1 human immunodeficiency virus (HIV-1). ZAP selectively binds CpG dinucleotides through its N-terminal RNA-binding domain, which consists of four zinc fingers. ZAP also contains a central region that consists of a fifth zinc finger and two WWE domains. Through structural and biochemical studies, we found that the fifth zinc finger and tandem WWEs of ZAP combine into a single integrated domain that binds to poly(ADP-ribose) (PAR), a cellular polynucleotide. PAR binding is mediated by the second WWE module of ZAP and likely involves specific recognition of an adenosine diphosphate-containing unit of PAR. Mutation of the PAR binding site in ZAP abrogates the interaction in vitro and diminishes ZAP activity against a CpG-rich HIV-1 reporter virus and murine leukemia virus. In cells, PAR facilitates formation of non-membranous sub-cellular compartments such as DNA repair foci, spindle poles and cytosolic RNA stress granules. Our results suggest that ZAP-mediated viral mRNA degradation is facilitated by PAR, and provides a biophysical rationale for the reported association of ZAP with RNA stress granules.