Cell-type-specific repression of internal ribosome entry site activity by double-stranded RNA-binding protein 76.


Journal Article

Translation of picornavirus plus-strand RNA genomes occurs via internal ribosomal entry at highly structured 5' untranslated regions. In addition to canonical translation factors, translation rate is likely influenced by supplementary host and viral trans-acting factors. We previously reported that insertion of a heterologous human rhinovirus type 2 internal ribosomal entry site (IRES) into the poliovirus (PV) genome, generating the chimeric virus PV-RIPO, selectively abrogates viral translation and propagation in neurons, which eliminate poliovirus's signature neuropathogenicity. While severely deficient in cells of neuronal lineage, the rhinovirus IRES promotes efficient propagation of PV-RIPO in cancer cells. Tumor-specific IRES function can be therapeutically exploited to direct viral cytotoxicity to cancer cells. Neuron-glioma heterokaryon analysis implicates neuronal trans-dominant inhibition in this effect, suggesting that host trans-acting factors repress IRES function in a cell-type-specific manner. We identified a set of proteins from neuronal cells with affinity for the rhinovirus IRES, including double-stranded RNA-binding protein 76 (DRBP76). DRBP76 associates with the IRES in neuronal but not in malignant glioma cells. Moreover, DRBP76 depletion in neuronal cells enhances rhinovirus IRES-driven translation and virus propagation. Our observations suggest that cell-type-specific association of DRBP76 with the rhinovirus IRES represses PV-RIPO translation and propagation in neuronal cells.

Full Text

Duke Authors

Cited Authors

  • Merrill, MK; Dobrikova, EY; Gromeier, M

Published Date

  • April 2006

Published In

Volume / Issue

  • 80 / 7

Start / End Page

  • 3147 - 3156

PubMed ID

  • 16537583

Pubmed Central ID

  • 16537583

International Standard Serial Number (ISSN)

  • 0022-538X

Digital Object Identifier (DOI)

  • 10.1128/JVI.80.7.3147-3156.2006


  • eng

Conference Location

  • United States