| RRC ID |
53777
|
| 著者 |
Xia J, Chen LT, Mei Q, Ma CH, Halliday JA, Lin HY, Magnan D, Pribis JP, Fitzgerald DM, Hamilton HM, Richters M, Nehring RB, Shen X, Li L, Bates D, Hastings PJ, Herman C, Jayaram M, Rosenberg SM.
|
| タイトル |
Holliday junction trap shows how cells use recombination and a junction-guardian role of RecQ helicase.
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| ジャーナル |
Sci Adv
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| Abstract |
DNA repair by homologous recombination (HR) underpins cell survival and fuels genome instability, cancer, and evolution. However, the main kinds and sources of DNA damage repaired by HR in somatic cells and the roles of important HR proteins remain elusive. We present engineered proteins that trap, map, and quantify Holliday junctions (HJs), a central DNA intermediate in HR, based on catalytically deficient mutant RuvC protein of Escherichia coli. We use RuvCDefGFP (RDG) to map genomic footprints of HR at defined DNA breaks in E. coli and demonstrate genome-scale directionality of double-strand break (DSB) repair along the chromosome. Unexpectedly, most spontaneous HR-HJ foci are instigated, not by DSBs, but rather by single-stranded DNA damage generated by replication. We show that RecQ, the E. coli ortholog of five human cancer proteins, nonredundantly promotes HR-HJ formation in single cells and, in a novel junction-guardian role, also prevents apparent non-HR-HJs promoted by RecA overproduction. We propose that one or more human RecQ orthologs may act similarly in human cancers overexpressing the RecA ortholog RAD51 and find that cancer genome expression data implicate the orthologs BLM and RECQL4 in conjunction with EME1 and GEN1 as probable HJ reducers in such cancers. Our results support RecA-overproducing E. coli as a model of the many human tumors with up-regulated RAD51 and provide the first glimpses of important, previously elusive reaction intermediates in DNA replication and repair in single living cells.
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| 巻・号 |
2(11)
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| ページ |
e1601605
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| 公開日 |
2016-11-1
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| DOI |
10.1126/sciadv.1601605
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| PII |
1601605
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| PMID |
28090586
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| PMC |
PMC5222578
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| MeSH |
DNA Breaks, Single-Stranded*
DNA, Bacterial* / genetics
DNA, Bacterial* / metabolism
DNA, Cruciform* / genetics
DNA, Cruciform* / metabolism
DNA, Neoplasm / genetics
DNA, Neoplasm / metabolism
Escherichia coli* / genetics
Escherichia coli* / metabolism
Humans
Neoplasm Proteins / genetics
Neoplasm Proteins / metabolism
Neoplasms / genetics
Neoplasms / metabolism
Rad51 Recombinase / genetics
Rad51 Recombinase / metabolism
RecQ Helicases* / genetics
RecQ Helicases* / metabolism
Recombination, Genetic*
|
| IF |
13.117
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| 引用数 |
10
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| リソース情報 |
| 原核生物(大腸菌) |
|
