Calcium influx-mediated translocation of m-calpain induces Ku80 cleavage and enhances the Ku80-related DNA repair pathway
- 주제(키워드) m-calpain , Ku80-related DNA repair , adriamycin , DNA damage
- 등재 SCIE, SCOPUS
- 발행기관 IMPACT JOURNALS LLC
- 발행년도 2016
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000129896
- 본문언어 영어
- Published As http://dx.doi.org/10.18632/oncotarget.8791
초록/요약
Proteomic analysis of ionomycin-treated and untreated mammary epithelial MCF10A cells elucidated differences in Ku80 cleavage. Ku80, a subunit of the Ku protein complex, is an initiator of the non-homologous, end-joining (NHEJ), double-strand breaks (DSBs) repair pathway. The nuclear Ku80 was cleaved in a calcium concentration-dependent manner by m-calpain but not by m-calpain. The cleavage of nuclear Ku80 at its beta/chi{ domain was validated by Western blotting analysis using flag-tagged expression vectors of truncated versions of Ku80 and a flag antibody and was confirmed in m-calpain knock-down cells and in vitro cell-free evaluation with recombinant proteins of calpains, Ku70, and Ku80. In addition, the cleaved Ku80 still formed a Ku heterodimer and promoted DNA DSB repair activity. Taken together, these findings indicate that translocated m-calpain enhances the NHEJ pathway through the cleavage of Ku80. Based on the present study, m-calpain in DNA repair pathways might be a novel anticancer drug target, or its mechanism might be a possible route for resistance acquisition of DNA damage-inducing chemotherapeutics.
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