气候变化领域集成服务门户(CCPortal): Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination

CCPortal

DOI	10.1073/PNAS.2021963118
	Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination
	Whelan D.R.; Rothenberg E.
发表日期	2021
ISSN	00278424
卷号	118 期号:11
英文摘要	Homologous recombination (HR) is a major pathway for repair of DNA double-strand breaks (DSBs). The initial step that drives the HR process is resection of DNA at the DSB, during which a multitude of nucleases, mediators, and signaling proteins accumulates at the damage foci in a manner that remains elusive. Using single-molecule localization super-resolution (SR) imaging assays, we specifically visualize the spatiotemporal behavior of key mediator and nuclease proteins as they resect DNA at single-ended double-strand breaks (seDSBs) formed at collapsed replication forks. By characterizing these associations, we reveal the in vivo dynamics of resection complexes involved in generating the long single-stranded DNA (ssDNA) overhang prior to homology search. We show that 53BP1, a protein known to antagonize HR, is recruited to seDSB foci during early resection but is spatially separated from repair activities. Contemporaneously, CtBP-interacting protein (CtIP) and MRN (MRE11-RAD51-NBS1) associate with seDSBs, interacting with each other and BRCA1. The HR nucleases EXO1 and DNA2 are also recruited and colocalize with each other and with the repair helicase Bloom syndrome protein (BLM), demonstrating multiple simultaneous resection events. Quantification of replication protein A (RPA) accumulation and ssDNA generation shows that resection is completed 2 to 4 h after break induction. However, both BRCA1 and BLM persist later into HR, demonstrating potential roles in homology search and repair resolution. Furthermore, we show that initial recruitment of BRCA1 and removal of Ku are largely independent of MRE11 exonuclease activity but dependent on MRE11 endonuclease activity. Combined, our observations provide a detailed description of resection during HR repair. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	BRCA1; DNA damage; DNA repair; Homologous recombination; Resection
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180313
作者单位	Department of Pharmacy and Biomedical Sciences, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC 3552, Australia; Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, United States
推荐引用方式 GB/T 7714	Whelan D.R.,Rothenberg E.. Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination[J],2021,118(11).
APA	Whelan D.R.,&Rothenberg E..(2021).Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination.Proceedings of the National Academy of Sciences of the United States of America,118(11).
MLA	Whelan D.R.,et al."Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination".Proceedings of the National Academy of Sciences of the United States of America 118.11(2021).