Altering murine leukemia virus integration through disruption of the integrase and BET protein family interaction

Nucleic Acids Res. 2014 May;42(9):5917-28. doi: 10.1093/nar/gku175. Epub 2014 Mar 12.


We report alterations to the murine leukemia virus (MLV) integrase (IN) protein that successfully result in decreasing its integration frequency at transcription start sites and CpG islands, thereby reducing the potential for insertional activation. The host bromo and extraterminal (BET) proteins Brd2, 3 and 4 interact with the MLV IN protein primarily through the BET protein ET domain. Using solution NMR, protein interaction studies, and next generation sequencing, we show that the C-terminal tail peptide region of MLV IN is important for the interaction with BET proteins and that disruption of this interaction through truncation mutations affects the global targeting profile of MLV vectors. The use of the unstructured tails of gammaretroviral INs to direct association with complexes at active promoters parallels that used by histones and RNA polymerase II. Viruses bearing MLV IN C-terminal truncations can provide new avenues to improve the safety profile of gammaretroviral vectors for human gene therapy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • CpG Islands
  • HEK293 Cells
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Integrases / chemistry*
  • Leukemia Virus, Murine / genetics*
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • RNA-Binding Proteins / chemistry*
  • Sequence Analysis, DNA
  • Sequence Deletion
  • Transcription Factors
  • Transcription Initiation Site
  • Viral Proteins / chemistry*
  • Virus Integration*


  • BRD3 protein, human
  • RNA-Binding Proteins
  • Transcription Factors
  • Viral Proteins
  • Integrases

Associated data

  • PDB/2M9U