Additive Promotion of Viral Internal Ribosome Entry Site-Mediated Translation by Far Upstream Element-Binding Protein 1 and an Enterovirus 71-Induced Cleavage Product

PLoS Pathog. 2016 Oct 25;12(10):e1005959. doi: 10.1371/journal.ppat.1005959. eCollection 2016 Oct.

Abstract

The 5' untranslated region (5' UTR) of the enterovirus 71 (EV71) RNA genome contains an internal ribosome entry site (IRES) that is indispensable for viral protein translation. Due to the limited coding capacity of their RNA genomes, EV71 and other picornaviruses typically recruit host factors, known as IRES trans-acting factors (ITAFs), to mediate IRES-dependent translation. Here, we show that EV71 viral proteinase 2A is capable of cleaving far upstream element-binding protein 1 (FBP1), a positive ITAF that directly binds to the EV71 5' UTR linker region to promote viral IRES-driven translation. The cleavage occurs at the Gly-371 residue of FBP1 during the EV71 infection process, and this generates a functional cleavage product, FBP11-371. Interestingly, the cleavage product acts to promote viral IRES activity. Footprinting analysis and gel mobility shift assay results showed that FBP11-371 similarly binds to the EV71 5' UTR linker region, but at a different site from full-length FBP1; moreover, FBP1 and FBP11-371 were found to act additively to promote IRES-mediated translation and virus yield. Our findings expand the current understanding of virus-host interactions with regard to viral recruitment and modulation of ITAFs, and provide new insights into translational control during viral infection.

MeSH terms

  • 5' Untranslated Regions / physiology
  • Cell Line, Tumor
  • DNA Helicases / metabolism*
  • DNA-Binding Proteins / metabolism*
  • Electrophoretic Mobility Shift Assay
  • Enterovirus A, Human*
  • Gene Expression Regulation, Viral / physiology*
  • Host-Parasite Interactions / physiology*
  • Humans
  • Immunoblotting
  • Immunoprecipitation
  • Internal Ribosome Entry Sites / genetics
  • Internal Ribosome Entry Sites / physiology*
  • Protein Biosynthesis / physiology
  • RNA-Binding Proteins
  • Viral Proteins / metabolism*

Substances

  • 5' Untranslated Regions
  • DNA-Binding Proteins
  • FUBP1 protein, human
  • Internal Ribosome Entry Sites
  • RNA-Binding Proteins
  • Viral Proteins
  • DNA Helicases

Grants and funding

This work was supported by the Taiwan Ministry of Science and Technology (https://www.most.gov.tw/) grant 104-2632-B-182-002 awarded to SRS; and Chang Gung Memorial Hospital (https://www.cgmh.org.tw/eng2002/index.asp) grant CMRPD1E0401-403 awarded to SRS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.