TY - JOUR
T1 - Specificity of end resection pathways for double-strand break regions containing ribonucleotides and base lesions
AU - Daley, James M.
AU - Tomimatsu, Nozomi
AU - Hooks, Grace
AU - Wang, Weibin
AU - Miller, Adam S.
AU - Xue, Xiaoyu
AU - Nguyen, Kevin A.
AU - Kaur, Hardeep
AU - Williamson, Elizabeth
AU - Mukherjee, Bipasha
AU - Hromas, Robert
AU - Burma, Sandeep
AU - Sung, Patrick
N1 - Funding Information:
This study was supported by NIH grants R35 CA241801, R21 ES027154, RO1 CA197796, RO1 ES007061, RO1 CA205224, RO1 GM109645, PO1 CA092584, and P30 CA054174, by the National Aeronautics and Space Administration Award NNX16AD78G, a Team Science Grant from the Gray Foundation under the Basser Initiative, and by CPRIT REI Award RR180029. PS is the holder of the Robert A. Welch Distinguished Chair in Chemistry (AQ-0012). S.B. is the holder of the Mays Family Foundation Distinguished Chair in Oncology.
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - 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.
AB - 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.
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U2 - 10.1038/s41467-020-16903-4
DO - 10.1038/s41467-020-16903-4
M3 - Article
C2 - 32555206
AN - SCOPUS:85086742540
VL - 11
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 3088
ER -