Subcellular localization of hepatitis E virus (HEV) replicase

Virology. 2008 Jan 5;370(1):77-92. doi: 10.1016/j.virol.2007.07.036. Epub 2007 Sep 27.

Abstract

Hepatitis E virus (HEV) is a hepatotropic virus with a single sense-strand RNA genome of approximately 7.2 kb in length. Details of the intracellular site of HEV replication can pave further understanding of HEV biology. In-frame fusion construct of functionally active replicase-enhanced green fluorescent protein (EGFP) gene was made in eukaryotic expression vector. The functionality of replicase-EGFP fusion protein was established by its ability to synthesize negative-strand viral RNA in vivo, by strand-specific anchored RT-PCR and molecular beacon binding. Subcellular co-localization was carried out using organelle specific fluorophores and by immuno-electron microscopy. Fluorescence Resonance Energy Transfer (FRET) demonstrated the interaction of this protein with the 3' end of HEV genome. The results show localization of replicase on the endoplasmic reticulum membranes. The protein regions responsible for membrane localization was predicted and identified by use of deletion mutants. Endoplasmic reticulum was identified as the site of replicase localization and possible site of replication.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Line, Tumor
  • Endoplasmic Reticulum / metabolism*
  • Endoplasmic Reticulum / ultrastructure
  • Fluorescence Resonance Energy Transfer
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Hepatitis E virus / enzymology*
  • Hepatitis E virus / genetics
  • Humans
  • Microscopy, Electron, Transmission
  • Molecular Probes
  • Molecular Sequence Data
  • RNA, Viral / biosynthesis*
  • RNA, Viral / genetics
  • RNA-Dependent RNA Polymerase / genetics
  • RNA-Dependent RNA Polymerase / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Subcellular Fractions / metabolism
  • Virus Replication

Substances

  • Molecular Probes
  • RNA, Viral
  • Recombinant Fusion Proteins
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • RNA-Dependent RNA Polymerase