DNA-dependent protein kinase (DNA-PK) was discovered in early 1990s, when the catalytic activity of a protein kinase triggered by double-stranded DNA was reported for the first time. Interestingly, it was noted that the kinase functions efficiently only in the presence of linear but not supercoiled DNA (Carter et al. 1990). Independently, DNA-PK was reported to phosphorylate transcription factor Sp1 and a number of other DNA-binding proteins. Furthermore, protein Ku was identified as an essential component of DNA-PK and confirmed as a binding subunit that served to recruit DNA-PK catalytic subunit (DNA-PKcs) (Gottlieb and Jackson 1993). Another important breakthrough came from Stamato and his colleagues in 1994, who reported lack of double-strand break (DSB) DNA binding activity in radiosensitive rodent cell line and attributed it to the Ku heterodimer absence (Getts and Stamato 1994). Since then,...
- Iliakis G, Murmann T, Soni A. Alternative end-joining repair pathways are the ultimate backup for abrogated classical non-homologous end-joining and homologous recombination repair: Implications for the formation of chromosome translocations. Mutat Res Genet Toxicol Environ Mutagen. 2015;793:166–75.CrossRefPubMedGoogle Scholar