The adenovirus E1b55K/E4orf6 complex induces degradation of the Bloom helicase during infection

J Virol. 2011 Feb;85(4):1887-92. doi: 10.1128/JVI.02134-10. Epub 2010 Dec 1.


The adenovirus (Ad) E1b55K and E4orf6 gene products assemble an E3 ubiquitin ligase complex that promotes degradation of cellular proteins. Among the known substrates are p53 and the Mre11-Rad50-Nbs1 (MRN) complex. Since members of the RecQ helicase family function together with MRN in genome maintenance, we investigated whether adenovirus affects RecQ proteins. We show that Bloom helicase (BLM) is degraded during adenovirus type 5 (Ad5) infection. BLM degradation is mediated by E1b55K/E4orf6 but is independent of MRN. We detected BLM localized at discrete foci around viral replication centers. These studies identify BLM as a new substrate for degradation by the adenovirus E1b55K/E4orf6 complex.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenovirus E1B Proteins / genetics
  • Adenovirus E1B Proteins / metabolism*
  • Adenovirus E4 Proteins / genetics
  • Adenovirus E4 Proteins / metabolism*
  • Adenoviruses, Human / metabolism
  • Adenoviruses, Human / pathogenicity*
  • HeLa Cells
  • Humans
  • RecQ Helicases / genetics
  • RecQ Helicases / metabolism*
  • Substrate Specificity
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Virus Replication


  • Adenovirus E1B Proteins
  • Adenovirus E4 Proteins
  • Ubiquitin-Protein Ligases
  • RecQ Helicases