The repression domain of the E1B 55-kilodalton protein participates in countering interferon-induced inhibition of adenovirus replication.

TitleThe repression domain of the E1B 55-kilodalton protein participates in countering interferon-induced inhibition of adenovirus replication.
Publication TypeJournal Article
Year of Publication2013
AuthorsChahal, JS, Gallagher, C, DeHart, CJ, Flint, SJ
JournalJ Virol
Volume87
Issue8
Pagination4432-44
Date Published2013 Apr
ISSN1098-5514
KeywordsAdenovirus E1B Proteins, Adenoviruses, Human, Cell Line, DNA Mutational Analysis, DNA, Viral, Fibroblasts, Host-Pathogen Interactions, Humans, Immune Evasion, Interferons, Mutagenesis, Site-Directed, Virulence Factors, Virus Replication
Abstract

<p>To begin to investigate the mechanism by which the human adenovirus type 5 E1B 55-kDa protein protects against the antiviral effects of type 1 interferon (IFN) (J. S. Chahal, J. Qi, and S. J. Flint, PLoS Pathog. 8:e1002853, 2012 [doi:10.1371/journal.ppat.1002853]), we examined the effects of precise amino acid substitution in this protein on resistance of viral replication to the cytokine. Only substitution of residues 443 to 448 of E1B for alanine (E1B Sub19) specifically impaired production of progeny virus and resulted in a large defect in viral DNA synthesis in IFN-treated normal human fibroblasts. Untreated or IFN-treated cells infected by this mutant virus (AdEasyE1Sub19) contained much higher steady-state concentrations of IFN-inducible GBP1 and IFIT2 mRNAs than did wild-type-infected cells and of the corresponding newly transcribed pre-mRNAs, isolated exploiting 5'-ethynyluridine labeling and click chemistry. These results indicated that the mutations created by substitution of residues 443 to 448 for alanine (Sub19) impair repression of transcription of IFN-inducible genes, by the E1B, 55-kDa protein, consistent with their location in a segment required for repression of p53-dependent transcription. However, when synthesized alone, the E1B 55-kDa protein inhibited expression of the p53-regulated genes BAX and MDM2 but had no impact whatsoever on induction of IFIT2 and GBP1 expression by IFN. These observations correlate repression of transcription of IFN-inducible genes by the E1B 55-kDa protein with protection against inhibition of viral genome replication and indicate that the E1B 55-kDa protein is not sufficient to establish such transcriptional repression.</p>

DOI10.1128/JVI.03387-12
Alternate JournalJ. Virol.
PubMed ID23388716
PubMed Central IDPMC3624377
Grant ListR56 AI091785 / AI / NIAID NIH HHS / United States
R56AI1091785 / AI / NIAID NIH HHS / United States