A Non-enveloped Virus Hijacks Host Disaggregation Machinery to Translocate across the Endoplasmic Reticulum Membrane

PLoS Pathog. 2015 Aug 5;11(8):e1005086. doi: 10.1371/journal.ppat.1005086. eCollection 2015 Aug.

Abstract

Mammalian cytosolic Hsp110 family, in concert with the Hsc70:J-protein complex, functions as a disaggregation machinery to rectify protein misfolding problems. Here we uncover a novel role of this machinery in driving membrane translocation during viral entry. The non-enveloped virus SV40 penetrates the endoplasmic reticulum (ER) membrane to reach the cytosol, a critical infection step. Combining biochemical, cell-based, and imaging approaches, we find that the Hsp110 family member Hsp105 associates with the ER membrane J-protein B14. Here Hsp105 cooperates with Hsc70 and extracts the membrane-penetrating SV40 into the cytosol, potentially by disassembling the membrane-embedded virus. Hence the energy provided by the Hsc70-dependent Hsp105 disaggregation machinery can be harnessed to catalyze a membrane translocation event.

Publication types

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

MeSH terms

  • Biological Transport / physiology
  • Cell Line
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum / virology*
  • HSC70 Heat-Shock Proteins / metabolism
  • HSP110 Heat-Shock Proteins / metabolism
  • Host-Parasite Interactions / physiology*
  • Humans
  • Immunoblotting
  • Immunoprecipitation
  • Microscopy, Fluorescence
  • Polyomavirus Infections / metabolism*
  • Signal Transduction / physiology
  • Simian virus 40 / pathogenicity*
  • Transfection
  • Tumor Virus Infections / metabolism*

Substances

  • HSC70 Heat-Shock Proteins
  • HSP110 Heat-Shock Proteins
  • HSPA8 protein, human