The p150 Isoform of ADAR1 Blocks Sustained RLR signaling and Apoptosis during Influenza Virus Infection

PLoS Pathog. 2020 Sep 8;16(9):e1008842. doi: 10.1371/journal.ppat.1008842. eCollection 2020 Sep.

Abstract

Signaling through retinoic acid inducible gene I (RIG-I) like receptors (RLRs) is tightly regulated, with activation occurring upon sensing of viral nucleic acids, and suppression mediated by negative regulators. Under homeostatic conditions aberrant activation of melanoma differentiation-associated protein-5 (MDA5) is prevented through editing of endogenous dsRNA by RNA editing enzyme Adenosine Deaminase Acting on RNA (ADAR1). In addition, ADAR1 is postulated to play pro-viral and antiviral roles during viral infections that are dependent or independent of RNA editing activity. Here, we investigated the importance of ADAR1 isoforms in modulating influenza A virus (IAV) replication and revealed the opposing roles for ADAR1 isoforms, with the nuclear p110 isoform restricting versus the cytoplasmic p150 isoform promoting IAV replication. Importantly, we demonstrate that p150 is critical for preventing sustained RIG-I signaling, as p150 deficient cells showed increased IFN-β expression and apoptosis during IAV infection, independent of RNA editing activity. Taken together, the p150 isoform of ADAR1 is important for preventing sustained RIG-I induced IFN-β expression and apoptosis during viral infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • A549 Cells
  • Adenosine Deaminase / genetics
  • Adenosine Deaminase / metabolism*
  • Apoptosis*
  • DEAD Box Protein 58 / genetics
  • DEAD Box Protein 58 / metabolism*
  • HEK293 Cells
  • Humans
  • Influenza A virus / physiology*
  • Influenza, Human / genetics
  • Influenza, Human / metabolism*
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Receptors, Immunologic
  • Signal Transduction*
  • Virus Replication*

Substances

  • Isoenzymes
  • RNA-Binding Proteins
  • Receptors, Immunologic
  • ADAR protein, human
  • Adenosine Deaminase
  • RIGI protein, human
  • DEAD Box Protein 58