Double‐strand break repair mediated by DNA end‐joining

• Published in: Genes to cells : devoted to molecular & cellular mechanisms 1998-03, Vol.3 (3), p.135-144
• Main Authors: Tsukamoto, Yasumasa, Ikeda, Hideo
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; DNA - chemistry; DNA - genetics; DNA Repair; Humans; Models, Biological; Recombination, Genetic
• ISSN: 1356-9597; 1365-2443
• DOI: 10.1046/j.1365-2443.1998.00180.x

DNA double‐strand breaks formed by ionizing irradiation or other stresses are repaired by homologous recombination or DNA end‐joining. This review focuses on the mechanism of double‐strand break repair mediated by DNA end‐joining, in which many factors have recently been identified. After DNA double‐strand breakage, DNA end‐joining takes place between the DNA ends that have nonhomologous sequences or very short regions of homology. The broken DNA is repaired if the DNA end‐joining occurs in the same molecule, while it causes chromosome aberrations such as deletions, insertions, translocations and inversions if it occurs between different molecules. Rad50 and its relatives, Ku‐proteins, DNA ligase VI and silencing factors, are involved in DNA end‐joining in yeast and mammalian cells. These findings led us to propose a model in which the formation of a heterochromatin‐like complex at broken ends is an important element in DNA end‐joining.