Specificity of End Resection Pathways for Double-Strand Break Regions Containing Ribonucleotides and Base Lesions
Date
2020-06
Authors
Daley, James M.
Tomimatsu, Nozomi
Hooks, Grace
Wang, Weibin
Miller, Adam S.
Xue, Xiaoyu
Nguyen, Kevin A.
Kaur, Hardeep
Williamson, Elizabeth
Mukherjee, Bipasha
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
DNA double-strand break repair by homologous recombination begins with nucleolytic resection of the 5’ DNA strand at the break ends. Long-range resection is catalyzed by EXO1 and BLM-DNA2, which likely have to navigate through ribonucleotides and damaged bases. Here, we show that a short stretch of ribonucleotides at the 5’ terminus stimulates resection by EXO1. Ribonucleotides within a 5’ flap are resistant to cleavage by DNA2, and extended RNA:DNA hybrids inhibit both strand separation by BLM and resection by EXO1. Moreover, 8-oxo-guanine impedes EXO1 but enhances resection by BLM-DNA2, and an apurinic/ apyrimidinic site stimulates resection by BLM-DNA2 and DNA strand unwinding by BLM. Accordingly, depletion of OGG1 or APE1 leads to greater dependence of DNA resection on DNA2. Importantly, RNase H2A deficiency impairs resection overall, which we attribute to the accumulation of long RNA:DNA hybrids at DNA ends. Our results help explain why eukaryotic cells possess multiple resection nucleases.
Description
Keywords
DNA, double-strand break repair, ribonucleotides, Chemistry and Biochemistry
Citation
Daley, J. M., Tomimatsu, N., Hooks, G., Wang, W., Miller, A. S., Xue, X., Nguyen, K. A., Kaur, H., Williamson, E., Mukherjee, B., Hromas, R., Burma, S., & Sung, P. (2020). Specificity of end resection pathways for double-strand break regions containing ribonucleotides and base lesions. Nature Communications, 11(1), pp. 1-12.
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© The Author(s) 2020.
Rights License
This work is licensed under a Creative Commons Attribution 4.0 International License.