A novel DDB2-ATM feedback loop regulates human cytomegalovirus replication

J Virol. 2014 Feb;88(4):2279-90. doi: 10.1128/JVI.03423-13. Epub 2013 Dec 11.


Human cytomegalovirus (HCMV) genome replication requires host DNA damage responses (DDRs) and raises the possibility that DNA repair pathways may influence viral replication. We report here that a nucleotide excision repair (NER)-associated-factor is required for efficient HCMV DNA replication. Mutations in genes encoding NER factors are associated with xeroderma pigmentosum (XP). One of the XP complementation groups, XPE, involves mutation in ddb2, which encodes DNA damage binding protein 2 (DDB2). Infectious progeny virus production was reduced by >2 logs in XPE fibroblasts compared to levels in normal fibroblasts. The levels of immediate early (IE) (IE2), early (E) (pp65), and early/late (E/L) (gB55) proteins were decreased in XPE cells. These replication defects were rescued by infection with a retrovirus expressing DDB2 cDNA. Similar patterns of reduced viral gene expression and progeny virus production were also observed in normal fibroblasts that were depleted for DDB2 by RNA interference (RNAi). Mature replication compartments (RCs) were nearly absent in XPE cells, and there were 1.5- to 2.0-log reductions in viral DNA loads in infected XPE cells relative to those in normal fibroblasts. The expression of viral genes (UL122, UL44, UL54, UL55, and UL84) affected by DDB2 status was also sensitive to a viral DNA replication inhibitor, phosphonoacetic acid (PAA), suggesting that DDB2 affects gene expression upstream of or events associated with the initiation of DNA replication. Finally, a novel, infection-associated feedback loop between DDB2 and ataxia telangiectasia mutated (ATM) was observed in infected cells. Together, these results demonstrate that DDB2 and a DDB2-ATM feedback loop influence HCMV replication.

Publication types

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

MeSH terms

  • Ataxia Telangiectasia Mutated Proteins / genetics
  • Ataxia Telangiectasia Mutated Proteins / metabolism
  • Cytomegalovirus / genetics
  • Cytomegalovirus / physiology*
  • DNA-Binding Proteins / genetics*
  • Feedback, Physiological / physiology*
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Viral / genetics
  • Gene Expression Regulation, Viral / physiology*
  • Genes, Immediate-Early / genetics
  • Humans
  • Immunoblotting
  • Mutation / genetics
  • RNA Interference
  • RNA, Small Interfering / genetics
  • Real-Time Polymerase Chain Reaction
  • Transduction, Genetic
  • Transfection
  • Virus Replication / genetics
  • Virus Replication / physiology*


  • DDB2 protein, human
  • DNA-Binding Proteins
  • RNA, Small Interfering
  • Ataxia Telangiectasia Mutated Proteins