Defining functional domains of Ku80: DNA end binding and survival after radiation

O. Osipovich, R. J. Duhe, P. Hasty, S. K. Durum, K. Muegge

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


The Ku heterodimeric protein (Ku80/Ku70) is an essential component of the double-strand break DNA repair pathway in mammalian cells. We have recently defined a central region within Ku80 that is required for heterodimerization with Ku70. We now identified a core region within Ku80 (amino acids 210 to 531) that is necessary for binding of Ku to DNA ends. Interaction with Ku70 and DNA end binding are important for Ku80 function in vivo since Ku80 mutants lacking DNA end binding activity were unable to restore radiation resistance in Ku80 deficient fibroblast cell lines. However, Ku80 mutants were identified that retained DNA end binding activity but were unable to restore radiation survival, thus pointing to additional functional properties of Ku80. An N-terminal deletional mutant of Ku80 was able to suppress wild type Ku80 function for radiation survival in several cell lines, thus demonstrating dominant negative function.

Original languageEnglish (US)
Pages (from-to)802-807
Number of pages6
JournalBiochemical and Biophysical Research Communications
Issue number3
StatePublished - Aug 11 1999
Externally publishedYes

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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