Electronic versions


  • K G Manolis
    University of Sussex
  • E R Nimmo
    Western General Hospital, Edinburgh
  • E Hartsuiker
    University of Sussex
  • A M Carr
    University of Sussex
  • P A Jeggo
    University of Sussex
  • R C Allshire
    Western General Hospital, Edinburgh

DNA double strand break (DSB) repair by non-homologous end joining (NHEJ) in mammalian cells requires the Ku70-Ku80 heterodimer, the DNA-PK catalytic subunit DNA-PKcs, as well as DNA ligase IV and Xrcc4. NHEJ of plasmid DSBs in Saccharomyces cerevisiae requires Ku, Xrcc4 and DNA ligase IV, as well as Mre11, Rad50, Xrs2 and DNA damage checkpoint proteins. Saccharomyces cerevisiae Ku is also required for telomere length maintenance and transcriptional silencing. We have characterized NHEJ in Schizosaccharomyces pombe using an extrachromosomal assay and find that, as anticipated, it is Ku70 and DNA ligase IV dependent. Unexpectedly, we find that Rad32, Rad50 (the S.pombe homologues of Mre11 and Rad50, respectively) and checkpoint proteins are not required for NHEJ. Furthermore, although S.pombe Ku70 is required for maintenance of telomere length, it is dispensable for transcriptional silencing at telomeres and is located throughout the nucleus rather than concentrated at the telomeres. Together, these results provide insight into the mechanism of NHEJ and contrast significantly with recent studies in S.cerevisiae.


  • Animals, Antigens, Nuclear, Base Sequence, Bleomycin, Cell Nucleus, DNA Damage, DNA Helicases, DNA Ligase ATP, DNA Ligases, DNA Repair, DNA, Fungal, DNA-Binding Proteins, Fungal Proteins, Gamma Rays, Gene Silencing, Ku Autoantigen, Mammals, Molecular Sequence Data, Nuclear Proteins, Restriction Mapping, Saccharomyces cerevisiae Proteins, Schizosaccharomyces, Telomere, Temperature, Transcription Factors, Journal Article, Research Support, Non-U.S. Gov't
Original languageEnglish
Pages (from-to)210-21
Number of pages12
JournalEMBO Journal
Issue number1-2
Publication statusPublished - 15 Jan 2001
Externally publishedYes
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