HSV-1 Cgal+ infection promotes quaking RNA binding protein production and induces nuclear-cytoplasmic shuttling of quaking I-5 isoform in human hepatoma cells

Mol Cell Proteomics. 2011 Jun;10(6):M111.009126. doi: 10.1074/mcp.M111.009126. Epub 2011 Apr 5.

Abstract

Herpesvirus type 1 (HSV-1) based oncolytic vectors arise as a promising therapeutic alternative for neoplastic diseases including hepatocellular carcinoma. However, the mechanisms mediating the host cell response to such treatments are not completely known. It is well established that HSV-1 infection induces functional and structural alterations in the nucleus of the host cell. In the present work, we have used gel-based and shotgun proteomic strategies to elucidate the signaling pathways impaired in the nucleus of human hepatoma cells (Huh7) upon HSV-1 Cgal(+) infection. Both approaches allowed the identification of differential proteins suggesting impairment of cell functions involved in many aspects of host-virus interaction such as transcription regulation, mRNA processing, and mRNA splicing. Based on our proteomic data and additional functional studies, cellular protein quaking content (QKI) increases 4 hours postinfection (hpi), when viral immediate-early genes such as ICP4 and ICP27 could be also detected. Depletion of QKI expression by small interfering RNA results in reduction of viral immediate-early protein levels, subsequent decrease in early and late viral protein content, and a reduction in the viral yield indicating that QKI directly interferes with viral replication. In particular, HSV-1 Cgal(+) induces a transient increase in quaking I-5 isoform (QKI-5) levels, in parallel with an enhancement of p27(Kip1) protein content. Moreover, immunofluorescence microscopy showed an early nuclear redistribution of QKI-5, shuttling from the nucleus to the cytosol and colocalizing with nectin-1 in cell to cell contact regions at 16-24 hpi. This evidence sheds new light on mechanisms mediating hepatoma cell response to HSV-1 vectors highlighting QKI as a central molecular mediator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Cell Adhesion Molecules / metabolism
  • Cell Line, Tumor
  • Cell Nucleus / metabolism*
  • Cell Nucleus / virology
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p57 / metabolism
  • Cytoplasm / metabolism*
  • Herpes Simplex / metabolism*
  • Herpes Simplex / virology
  • Herpesvirus 1, Human / genetics
  • Herpesvirus 1, Human / growth & development
  • Herpesvirus 1, Human / physiology*
  • Humans
  • Nectins
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Protein Transport
  • RNA Interference
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Statistics, Nonparametric
  • Tandem Mass Spectrometry
  • Two-Dimensional Difference Gel Electrophoresis
  • Viral Plaque Assay
  • Viral Proteins / metabolism

Substances

  • CDKN1C protein, human
  • Cell Adhesion Molecules
  • Cyclin-Dependent Kinase Inhibitor p57
  • NECTIN1 protein, human
  • Nectins
  • Protein Isoforms
  • QKI protein, human
  • RNA-Binding Proteins
  • Viral Proteins
  • Cyclin-Dependent Kinase Inhibitor p27