Restriction of hepatitis B virus replication by c-Abl-induced proteasomal degradation of the viral polymerase

Sci Adv. 2019 Feb 6;5(2):eaau7130. doi: 10.1126/sciadv.aau7130. eCollection 2019 Feb.

Abstract

About 257 million people with chronic infection of hepatitis B virus (HBV) worldwide are at high risk of developing terminal liver diseases. Reactivation of virus replication has been frequently reported in those patient populations receiving imatinib (an Abl kinase inhibitor) or bortezomib (a proteasome inhibitor) to treat concurrent diseases, but the underlying mechanism for this reactivation is unknown. We report that the HBV polymerase protein is recruited by Cdt2 to the cullin-RING ligase 4 (CRL4) for ubiquitination and proteasome degradation and that this process is stimulated by the c-Abl nonreceptor tyrosine kinase. Genetic ablation of the Abl-CRL4Cdt2 axis or pharmaceutical inhibition of this process stabilizes HBV polymerase protein and increases viral loads in HBV-infected liver cancer cell lines. Our study reveals a kinase-dependent activation of CRL4 ubiquitin ligase that can be targeted for blocking HBV replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Enzyme Stability
  • Gene Products, pol / metabolism*
  • Hepatitis B / metabolism*
  • Hepatitis B / virology*
  • Hepatitis B virus / physiology*
  • Host-Pathogen Interactions*
  • Humans
  • Models, Biological
  • Nuclear Proteins / metabolism
  • Proteasome Endopeptidase Complex / metabolism*
  • Protein Binding
  • Proteolysis
  • Proto-Oncogene Proteins c-abl / metabolism*
  • Substrate Specificity
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination
  • Virus Replication*

Substances

  • DTL protein, human
  • Gene Products, pol
  • IL17RB protein, human
  • Nuclear Proteins
  • P protein, Hepatitis B virus
  • Ubiquitin-Protein Ligases
  • Proto-Oncogene Proteins c-abl
  • Proteasome Endopeptidase Complex