SENP3-mediated host defense response contains HBV replication and restores protein synthesis

PLoS One. 2019 Jan 14;14(1):e0209179. doi: 10.1371/journal.pone.0209179. eCollection 2019.

Abstract

Certain organs are capable of containing the replication of various types of viruses. In the liver, infection of Hepatitis B virus (HBV), the etiological factor of Hepatitis B and hepatocellular carcinoma (HCC), often remains asymptomatic and leads to a chronic carrier state. Here we investigated how hepatocytes contain HBV replication and promote their own survival by orchestrating a translational defense mechanism via the stress-sensitive SUMO-2/3-specific peptidase SENP3. We found that SENP3 expression level decreased in HBV-infected hepatocytes in various models including HepG2-NTCP cell lines and a humanized mouse model. Downregulation of SENP3 reduced HBV replication and boosted host protein translation. We also discovered that IQGAP2, a Ras GTPase-activating-like protein, is a key substrate for SENP3-mediated de-SUMOylation. Downregulation of SENP3 in HBV infected cells facilitated IQGAP2 SUMOylation and degradation, which leads to suppression of HBV gene expression and restoration of global translation of host genes via modulation of AKT phosphorylation. Thus, The SENP3-IQGAP2 de-SUMOylation axis is a host defense mechanism of hepatocytes that restores host protein translation and suppresses HBV gene expression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism*
  • Down-Regulation
  • Gene Expression Regulation, Viral
  • Gene Knockdown Techniques
  • Hep G2 Cells
  • Hepatitis B / metabolism
  • Hepatitis B / virology
  • Hepatitis B virus / genetics
  • Hepatitis B virus / pathogenicity
  • Hepatitis B virus / physiology*
  • Hepatocytes / metabolism*
  • Hepatocytes / virology*
  • Host Microbial Interactions / genetics
  • Host Microbial Interactions / physiology*
  • Humans
  • Mice
  • Mice, Transgenic
  • Models, Biological
  • Proto-Oncogene Proteins c-akt / metabolism
  • Substrate Specificity
  • Sumoylation
  • Virus Replication / physiology
  • ras GTPase-Activating Proteins / antagonists & inhibitors
  • ras GTPase-Activating Proteins / genetics
  • ras GTPase-Activating Proteins / metabolism

Substances

  • IQGAP2 protein, human
  • ras GTPase-Activating Proteins
  • Proto-Oncogene Proteins c-akt
  • Cysteine Endopeptidases
  • SENP3 protein, human