کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5510922 1539371 2017 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
DNA requirements for interaction of the C-terminal region of Ku80 with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs)
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
DNA requirements for interaction of the C-terminal region of Ku80 with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs)
چکیده انگلیسی


- The length and base composition of DNA ends affects Ku70/80-DNA-PKcs complex assembly.
- Ku80CTR is required for assembly of Ku70/80 and DNA-PKcs on blunt ended 25 bp DNA and 25 bp dsDNA with a poly dA ssDNA extension but not 25 bp dsDNA with a poly dT or poly dC ssDNA extension.
- The optimal scaffold for assembly of the Ku70/80-DNA-PKcs complex is dsDNA with a poly pyrimidine ssDNA extension.

Non-homologous end joining (NHEJ) is the major pathway for the repair of ionizing radiation induced DNA double strand breaks (DSBs) in human cells. Critical to NHEJ is the DNA-dependent interaction of the Ku70/80 heterodimer with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to form the DNA-PK holoenzyme. However, precisely how Ku recruits DNA-PKcs to DSBs ends to enhance its kinase activity has remained enigmatic, with contradictory findings reported in the literature. Here we address the role of the Ku80 C-terminal region (CTR) in the DNA-dependent interaction of Ku70/80 with DNA-PKcs using purified components and defined DNA structures. Our results show that the Ku80 CTR is required for interaction with DNA-PKcs on short segments of blunt ended 25 bp dsDNA or 25 bp dsDNA with a 15-base poly dA single stranded (ss) DNA extension, but this requirement is less stringent on longer dsDNA molecules (35 bp blunt ended dsDNA) or 25 bp duplex DNA with either a 15-base poly dT or poly dC ssDNA extension. Moreover, the DNA-PKcs-Ku complex preferentially forms on 25 bp DNA with a poly-pyrimidine ssDNA extension.Our work clarifies the role of the Ku80 CTR and dsDNA ends on the interaction of DNA-PKcs with Ku and provides key information to guide assembly and biology of NHEJ complexes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: DNA Repair - Volume 57, September 2017, Pages 17-28
نویسندگان
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