PLoS ONE (Jan 2013)

Chromatin compaction protects genomic DNA from radiation damage.

  • Hideaki Takata,
  • Tomo Hanafusa,
  • Toshiaki Mori,
  • Mari Shimura,
  • Yutaka Iida,
  • Kenichi Ishikawa,
  • Kenichi Yoshikawa,
  • Yuko Yoshikawa,
  • Kazuhiro Maeshima

DOI
https://doi.org/10.1371/journal.pone.0075622
Journal volume & issue
Vol. 8, no. 10
p. e75622

Abstract

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Genomic DNA is organized three-dimensionally in the nucleus, and is thought to form compact chromatin domains. Although chromatin compaction is known to be essential for mitosis, whether it confers other advantages, particularly in interphase cells, remains unknown. Here, we report that chromatin compaction protects genomic DNA from radiation damage. Using a newly developed solid-phase system, we found that the frequency of double-strand breaks (DSBs) in compact chromatin after ionizing irradiation was 5-50-fold lower than in decondensed chromatin. Since radical scavengers inhibited DSB induction in decondensed chromatin, condensed chromatin had a lower level of reactive radical generation after ionizing irradiation. We also found that chromatin compaction protects DNA from attack by chemical agents. Our findings suggest that genomic DNA compaction plays an important role in maintaining genomic integrity.