Accumulation of Ku70 at DNA double-strand breaks in living epithelial cells

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Experimental Cell Research

DOI:https://doi.org/10.1016/J.YEXCR.2011.07.018· OSTI ID:22212178

Koike, Manabu ^[1]; Yutoku, Yasutomo ^[1]; Koike, Aki ^[1]

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1. DNA Repair Gene Research, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

Ku70 and Ku80 play an essential role in the DNA double-strand break (DSB) repair pathway, i.e., nonhomologous DNA-end-joining (NHEJ). No accumulation mechanisms of Ku70 at DSBs have been clarified in detail, although the accumulation mechanism of Ku70 at DSBs plays key roles in regulating the NHEJ activity. Here, we show the essential domains for the accumulation and function of Ku70 at DSBs in living lung epithelial cells. Our results showed that EGFP-Ku70 accumulation at DSBs began immediately after irradiation. Our findings demonstrate that three domains of Ku70, i.e., the {alpha}/{beta}, DNA-binding, and Ku80-binding domains, but not the SAP domain, are necessary for the accumulation at or recognition of DSBs in the early stage after irradiation. Moreover, our findings demonstrate that the leucine at amino acid 385 of Ku70 in the Ku80-binding domain, but not the three target amino acids for acetylation in the DNA-binding domain, is involved in the localization and accumulation of Ku70 at DSBs. Furthermore, accumulations of XRCC4 and XLF, but not that of Artemis, at DSBs are dependent on the presence of Ku70. These findings suggest that Artemis can work in not only the Ku-dependent repair process, but also the Ku-independent process at DSBs in living epithelial cells.

• OSTI ID: 22212178
• Journal Information: Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 17 Vol. 317; ISSN 0014-4827; ISSN ECREAL
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ACETYLATION
BIOLOGICAL PATHWAYS
DNA
IRRADIATION
LEUCINE
LUNGS
PROTEINS
STRAND BREAKS