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Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites
09:31

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites

Published on: March 22, 2016

BET proteins promote efficient murine leukemia virus integration at transcription start sites

Amit Sharma1, Ross C Larue, Matthew R Plumb

  • 1Center for Retrovirus Research, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA.

Proceedings of the National Academy of Sciences of the United States of America
|July 3, 2013
PubMed

Insights

Bromodomain and extraterminal domain (BET) proteins bind to Moloney murine leukemia virus (MLV) integrase, promoting its integration into the host genome. Inhibiting BET proteins reduces MLV integration at transcription start sites, suggesting a new therapeutic target.

Area of Science:

  • Molecular Biology
  • Virology
  • Gene Therapy

Background:

  • Retroviral DNA integration into the host genome is a critical step in viral replication and gene therapy vector design.
  • Murine leukemia virus (MLV) preferentially integrates near transcription start sites, but the mechanism remains unclear.

Purpose of the Study:

  • To identify cellular factors involved in MLV integration targeting.
  • To elucidate the mechanism of MLV integration site selection.
  • To explore potential therapeutic strategies for safer MLV-based vectors.

Main Methods:

  • Co-immunoprecipitation and in vitro binding assays to identify MLV integrase interacting proteins.
  • Biochemical assays to assess the effect of BET proteins on MLV integration.
  • ChIP-sequencing to map BET protein binding sites.
  • Inhibition studies using JQ-1 small molecule and RNA interference to assess the role of BET proteins in MLV integration.

Main Results:

  • Bromodomain and extraterminal domain (BET) proteins (Brd2, -3, -4) were identified as binding partners of MLV integrase.
  • Recombinant Brd4 protein binds MLV integrase and enhances in vitro integration.
  • The BET inhibitor JQ-1 impaired MLV integration in infected cells.
  • Significant positive correlation was observed between BET protein binding sites and MLV integration sites.
  • Antagonism of BET proteins reduced MLV integration frequency at transcription start sites.

Conclusions:

  • BET proteins are crucial for the efficiency and targeting of MLV integration.
  • BET proteins play a significant role in directing MLV DNA to transcription start sites.
  • Targeting BET proteins offers a potential strategy for developing safer MLV-based gene therapy vectors.
Keywords:
retroviral gene therapyvirus–host interactions

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