TY - JOUR
T1 - Abraxas suppresses DNA end resection and limits break-induced replication by controlling SLX4/MUS81 chromatin loading in response to TOP1 inhibitor-induced DNA damage
AU - Wu, Xiao
AU - Wang, Bin
N1 - Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Although homologous recombination (HR) is indicated as a high-fidelity repair mechanism, break-induced replication (BIR), a subtype of HR, is a mutagenic mechanism that leads to chromosome rearrangements. It remains poorly understood how cells suppress mutagenic BIR. Trapping of Topoisomerase 1 by camptothecin (CPT) in a cleavage complex on the DNA can be transformed into single-ended double-strand breaks (seDSBs) upon DNA replication or colliding with transcriptional machinery. Here, we demonstrate a role of Abraxas in limiting seDSBs undergoing BIR-dependent mitotic DNA synthesis. Through counteracting K63-linked ubiquitin modification, Abraxas restricts SLX4/Mus81 recruitment to CPT damage sites for cleavage and subsequent resection processed by MRE11 endonuclease, CtIP, and DNA2/BLM. Uncontrolled SLX4/MUS81 loading and excessive end resection due to Abraxas-deficiency leads to increased mitotic DNA synthesis via RAD52- and POLD3- dependent, RAD51-independent BIR and extensive chromosome aberrations. Our work implicates Abraxas/BRCA1-A complex as a critical regulator that restrains BIR for protection of genome stability.
AB - Although homologous recombination (HR) is indicated as a high-fidelity repair mechanism, break-induced replication (BIR), a subtype of HR, is a mutagenic mechanism that leads to chromosome rearrangements. It remains poorly understood how cells suppress mutagenic BIR. Trapping of Topoisomerase 1 by camptothecin (CPT) in a cleavage complex on the DNA can be transformed into single-ended double-strand breaks (seDSBs) upon DNA replication or colliding with transcriptional machinery. Here, we demonstrate a role of Abraxas in limiting seDSBs undergoing BIR-dependent mitotic DNA synthesis. Through counteracting K63-linked ubiquitin modification, Abraxas restricts SLX4/Mus81 recruitment to CPT damage sites for cleavage and subsequent resection processed by MRE11 endonuclease, CtIP, and DNA2/BLM. Uncontrolled SLX4/MUS81 loading and excessive end resection due to Abraxas-deficiency leads to increased mitotic DNA synthesis via RAD52- and POLD3- dependent, RAD51-independent BIR and extensive chromosome aberrations. Our work implicates Abraxas/BRCA1-A complex as a critical regulator that restrains BIR for protection of genome stability.
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U2 - 10.1038/s41467-021-24665-w
DO - 10.1038/s41467-021-24665-w
M3 - Article
C2 - 34272385
AN - SCOPUS:85110561077
SN - 2041-1723
VL - 12
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 4373
ER -