相关论文
1997 - Molecular and cellular biology
A fission yeast homolog of CDC20/p55CDC/Fizzy is required for recovery from DNA damage and genetically interacts with p34cdc2

Successful recovery from DNA damage requires coordination of several biological processes. Eukaryotic cell cycle progression is delayed when the cells encounter DNA-damaging agents. This cell cycle delay allows the cells to cope with DNA damage by utilizing DNA repair enzymes. Thus, at least two processes, induction of the cell cycle delay and repair of damaged DNA, are coordinately required for recovery. In this study, a fission yeast rad mutant (slp1-362) was genetically investigated. In response to radiation, slp1 stops cell division; however, it does not restart it. This defect is suppressed when slp1-362 is combined with wee1-50 or cdc2-3w; in these mutants, the onset of mitosis is advanced due to the premature activation of p34cdc2. In contrast, slp1 is synthetically lethal with cdc25, nim1/cdr1, or cdr2, all of which are unable to activate the p34cdc2 kinase correctly. These genetic interactions of slp1 with cdc2 and its modulators imply that slp1 is not defective in either "induction of cell cycle delay" or "DNA repair." slp1+ may be involved in a critical process which restarts cell cycle progression after the completion of DNA repair. Molecular cloning of slp1+ revealed that slp1+ encodes a putative 488-amino-acid polypeptide exhibiting significant homology to WD-domain proteins, namely, CDC20 (budding yeast), p55CDC (human), and Fizzy (fly). A possible role of slp1+ is proposed.

2010 - The Journal of Immunology
Hepatitis C Virus Inhibits DNA Damage Repair through Reactive Oxygen and Nitrogen Species and by Interfering with the ATM-NBS1/Mre11/Rad50 DNA Repair Pathway in Monocytes and Hepatocytes

Hepatitis C virus (HCV) infection is associated with the development of hepatocellular carcinoma and putatively also non-Hodgkin’s B cell lymphoma. In this study, we demonstrated that PBMCs obtained from HCV-infected patients showed frequent chromosomal aberrations and that HCV infection of B cells in vitro induced enhanced chromosomal breaks and sister chromatid exchanges. HCV infection hypersensitized cells to ionizing radiation and bleomycin and inhibited nonhomologous end-joining repair. The viral core and nonstructural protein 3 proteins were shown to be responsible for the inhibition of DNA repair, mediated by NO and reactive oxygen species. Stable expression of core protein induced frequent chromosome translocations in cultured cells and in transgenic mice. HCV core protein binds to the NBS1 protein and inhibits the formation of the Mre11/NBS1/Rad50 complex, thereby affecting ATM activation and inhibiting DNA binding of repair enzymes. Taken together, these data indicate that HCV infection inhibits multiple DNA repair processes to potentiate chromosome instability in both monocytes and hepatocytes. These effects may explain the oncogenicity and immunological perturbation of HCV infection.

1999 - Proteins
Crystal structure of Escherichia coli uracil DNA glycosylase and its complexes with uracil and glycerol: Structure and glycosylase mechanism revisited

The DNA repair enzyme uracil DNA glycosylase (UDG) catalyzes the hydrolysis of premutagenic uracil residues from single‐stranded or duplex DNA, producing free uracil and abasic DNA. Here we report the high‐resolution crystal structures of free UDG from Escherichia coli strain B (1.60 Å), its complex with uracil (1.50 Å), and a second active‐site complex with glycerol (1.43 Å). These represent the first high‐resolution structures of a prokaryotic UDG to be reported. The overall structure of the E. coli enzyme is more similar to the human UDG than the herpes virus enzyme. Significant differences between the bacterial and viral structures are seen in the side‐chain positions of the putative general‐acid (His187) and base (Asp64), similar to differences previously observed between the viral and human enzymes. In general, the active‐site loop that contains His187 appears preorganized in comparison with the viral and human enzymes, requiring smaller substrate‐induced conformational changes to bring active‐site groups into catalytic position. These structural differences may be related to the large differences in the mechanism of uracil recognition used by the E. coli and viral enzymes. The pH dependence of kcat for wild‐type UDG and the D64N and H187Q mutant enzymes is consistent with general‐base catalysis by Asp64, but provides no evidence for a general‐acid catalyst. The catalytic mechanism of UDG is critically discussed with respect to these results. Proteins 1999;35:13–24.  © 1999 Wiley‐Liss, Inc.

2007 - Journal of Biological Chemistry
A Triplex-forming Sequence from the Human c-MYC Promoter Interferes with DNA Transcription*

Naturally occurring DNA sequences that are able to form unusual DNA structures have been shown to be mutagenic, and in some cases the mutagenesis induced by these sequences is enhanced by their transcription. It is possible that transcription-coupled DNA repair induced at sites of transcription arrest might be involved in this mutagenesis. Thus, it is of interest to determine whether there are correlations between the mutagenic effects of such noncanonical DNA structures and their ability to arrest transcription. We have studied T7 RNA polymerase transcription through the sequence from the nuclease-sensitive element of the human c-MYC promoter, which is mutagenic in mammalian cells ( Wang, G., and Vasquez, K. M. (2004) Proc. Natl. Acad. Sci. U. S. A. 101, 13448-13453 ). This element has two mirror-symmetric homopurine-homopyrimidine blocks that potentially can form either DNA triplex (H-DNA) or quadruplex structures. We detected truncated transcription products indicating partial transcription arrest within and closely downstream of the element. The arrest required negative supercoiling and was much more pronounced when the pyrimidine-rich strand of the element served as the template. The exact positions of arrest sites downstream from the element depended upon the downstream flanking sequences. We made various nucleotide substitutions in the wild-type sequence from the c-MYC nuclease-sensitive element that specifically destabilize either the triplex or the quadruplex structure. When these substitutions were ranked for their effects on transcription, the results implicated the triplex structure in the transcription arrest. We suggest that transcription-induced triplex formation enhances pre-existing weak transcription pause sites within the flanking sequences by creating steric obstacles for the transcription machinery.

1989 - The Journal of biological chemistry
Enhanced DNA repair synthesis in hyperacetylated nucleosomes.

We have investigated the level of "early" DNA repair synthesis in nucleosome subpopulations, varying in histone acetylation, from normal human fibroblasts treated with sodium butyrate. We find that repair synthesis occurring during the first 30 min after UV irradiation is significantly enhanced in hyperacetylated mononucleosomes. Nucleosomes with an average of 2.3 acetyl residues/H4 molecule contained approximately 1.8-fold more repair synthesis than nucleosomes with an average of 1.5 or 1.0 acetyl residues/H4 molecule. Fractionation of highly acetylated nucleosomes by two-dimensional gel electrophoresis yielded an additional 2.0-fold enrichment of repair synthesis in nucleosomes containing 2.7 acetyl residues/H4 molecule as compared to nucleosomes containing 1.9 acetyl residues/H4 molecule. This enhanced repair synthesis is associated primarily with nucleosome core regions and does not appear to result from increased UV damage in hyperacetylated chromatin. In addition, the distribution of repair synthesis within nucleosome core DNA from hyperacetylated chromatin is nonrandom, showing a bias toward the 5' end which is similar to that obtained for bulk (unfractionated) chromatin. These results provide strong evidence that enhanced repair occurs within nucleosome cores of hyperacetylated chromatin in butyrate-treated human cells. Finally, pulse-chase experiments demonstrate that the association of enhanced repair synthesis with hyperacetylated nucleosomes is transient, lasting only about 12 h after UV damage.

2005 - Biochemical and biophysical research communications
The role of p53 in treatment responses of lung cancer.

Resistance to radio- and chemotherapy is a major problem in treatment responses of lung cancer. In this disease, biological markers, that can be predictive of response to treatment for guiding clinical practice, still need to be validated. Radiotherapy and most chemotherapeutic agents directly target DNA and in response to such therapies, p53 functions as a coordinator of the DNA repair process, cell cycle arrest, and apoptosis. In fact, it participates in the main DNA repair systems operative in cells, including NHEJ, HRR, NER, BER, and MMR. Given the high p53 mutation frequency in lung cancer which likely impairs some of the p53-mediated functions, a role of p53 as a predictive marker for treatment responses has been suggested. In this review, we summarize the conflicting results coming from preclinical and clinical studies on the role of p53 as a predictive marker of responses to chemotherapy or radiotherapy in lung cancer.

2000 - Proceedings of the National Academy of Sciences of the United States of America
The Holliday junction in an inverted repeat DNA sequence: sequence effects on the structure of four-way junctions.

Holliday junctions are important structural intermediates in recombination, viral integration, and DNA repair. We present here the single-crystal structure of the inverted repeat sequence d(CCGGTACCGG) as a Holliday junction at the nominal resolution of 2. 1 A. Unlike the previous crystal structures, this DNA junction has B-DNA arms with all standard Watson-Crick base pairs; it therefore represents the intermediate proposed by Holliday as being involved in homologous recombination. The junction is in the stacked-X conformation, with two interconnected duplexes formed by coaxially stacked arms, and is crossed at an angle of 41.4 degrees as a right-handed X. A sequence comparison with previous B-DNA and junction crystal structures shows that an ACC trinucleotide forms the core of a stable junction in this system. The 3'-C x G base pair of this ACC core forms direct and water-mediated hydrogen bonds to the phosphates at the crossover strands. Interactions within this core define the conformation of the Holliday junction, including the angle relating the stacked duplexes and how the base pairs are stacked in the stable form of the junction.

2007 - PLoS ONE
Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at its optimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to resistance; and strengthen the case for a role in survival of systems involved in manganese and iron homeostasis.

1995 - Annual review of genetics
DNA repair in humans.

DNA repair is an important molecular defense system against agents that cause cancer, degenerative diseases, and aging. Several repair systems in humans protect the genome by repairing modified bases, DNA adducts, crosslinks, and double strand breaks. These repair systems, base excision, nucleotide excision, and recombination, are intimately connected to transcription and to cell cycle checkpoints. In addition, genotoxic stress induces a set of cellular reactions mediated by the p53 tumor suppressor and the Ras oncogene. These genotoxic response reactions may help the cell survive or enter apoptosis. Damage-response reactions may be utilized as targets of anticancer chemotherapy.

2005 - Molecular and Cellular Biology
Involvement of Human MOF in ATM Function

ABSTRACT We have determined that hMOF, the human ortholog of the Drosophila MOF gene (males absent on the first), encoding a protein with histone acetyltransferase activity, interacts with the ATM (ataxia-telangiectasia-mutated) protein. Cellular exposure to ionizing radiation (IR) enhances hMOF-dependent acetylation of its target substrate, lysine 16 (K16) of histone H4 independently of ATM function. Blocking the IR-induced increase in acetylation of histone H4 at K16, either by the expression of a dominant negative mutant ΔhMOF or by RNA interference-mediated hMOF knockdown, resulted in decreased ATM autophosphorylation, ATM kinase activity, and the phosphorylation of downstream effectors of ATM and DNA repair while increasing cell killing. In addition, decreased hMOF activity was associated with loss of the cell cycle checkpoint response to DNA double-strand breaks. The overexpression of wild-type hMOF yielded the opposite results, i.e., a modest increase in cell survival and enhanced DNA repair after IR exposure. These results suggest that hMOF influences the function of ATM.

2018 - Nature
Predictable and precise template-free CRISPR editing of pathogenic variants

Following Cas9 cleavage, DNA repair without a donor template is generally considered stochastic, heterogeneous and impractical beyond gene disruption. Here, we show that template-free Cas9 editing is predictable and capable of precise repair to a predicted genotype, enabling correction of disease-associated mutations in humans. We constructed a library of 2,000 Cas9 guide RNAs paired with DNA target sites and trained inDelphi, a machine learning model that predicts genotypes and frequencies of 1- to 60-base-pair deletions and 1-base-pair insertions with high accuracy (r = 0.87) in five human and mouse cell lines. inDelphi predicts that 5–11% of Cas9 guide RNAs targeting the human genome are ‘precise-50’, yielding a single genotype comprising greater than or equal to 50% of all major editing products. We experimentally confirmed precise-50 insertions and deletions in 195 human disease-relevant alleles, including correction in primary patient-derived fibroblasts of pathogenic alleles to wild-type genotype for Hermansky–Pudlak syndrome and Menkes disease. This study establishes an approach for precise, template-free genome editing.The authors use a machine-learning algorithm to predict the spectrum of CRISPR–Cas9-nuclease-mediated DNA repair outcomes at human genomic target sites.

2010 - Cell
Identification of KIAA1018/FAN1, a DNA Repair Nuclease Recruited to DNA Damage by Monoubiquitinated FANCD2

DNA interstrand crosslinks (ICLs) are highly toxic because they block the progression of replisomes. The Fanconi Anemia (FA) proteins, encoded by genes that are mutated in FA, are important for repair of ICLs. The FA core complex catalyzes the monoubiquitination of FANCD2, and this event is essential for several steps of ICL repair. However, how monoubiquitination of FANCD2 promotes ICL repair at the molecular level is unknown. Here, we describe a highly conserved protein, KIAA1018/MTMR15/FAN1, that interacts with, and is recruited to sites of DNA damage by, the monoubiquitinated form of FANCD2. FAN1 exhibits endonuclease activity toward 5' flaps and has 5' exonuclease activity, and these activities are mediated by an ancient VRR_nuc domain. Depletion of FAN1 from human cells causes hypersensitivity to ICLs, defects in ICL repair, and genome instability. These data at least partly explain how ubiquitination of FANCD2 promotes DNA repair.

2013 - Science
Rif1 Prevents Resection of DNA Breaks and Promotes Immunoglobulin Class Switching

Fixing Broken DNA Some physiological processes, such as immunoglobulin class switching and telomere attrition, result in double-stranded DNA breaks. The DNA damage repair protein, 53BP1, prevents nucleolytic processing of these breaks, but the proteins it partners with to do this are unknown (see the Perspective by Lukas and Lukas). Di Virgilio et al. (p. 711, published online 10 January), using mass spectroscopy–based methods, and Zimmermann et al. (p. 700, published online 10 January), using a telomere-based assay, identify Rif1 as a 53BP1 phosphorylation- and DNA damage–dependent interaction partner. Mice with a B cell–specific deletion in Rif1 showed impaired immunoglobulin class switching. Rif1-deficient cells exhibited extensive 5′-3′ resection at DNA ends, with enhanced genetic instability. Thus, Rif1 partners with 53BP1 to promote the proper repair of double-stranded DNA breaks. In mammalian cells, Rap1-interacting factor 1 protects DNA ends against resection. [Also see Perspective by Lukas and Lukas] DNA double-strand breaks (DSBs) represent a threat to the genome because they can lead to the loss of genetic information and chromosome rearrangements. The DNA repair protein p53 binding protein 1 (53BP1) protects the genome by limiting nucleolytic processing of DSBs by a mechanism that requires its phosphorylation, but whether 53BP1 does so directly is not known. Here, we identify Rap1-interacting factor 1 (Rif1) as an ATM (ataxia-telangiectasia mutated) phosphorylation-dependent interactor of 53BP1 and show that absence of Rif1 results in 5′-3′ DNA-end resection in mice. Consistent with enhanced DNA resection, Rif1 deficiency impairs DNA repair in the G1 and S phases of the cell cycle, interferes with class switch recombination in B lymphocytes, and leads to accumulation of chromosome DSBs.

2008 - DNA repair
The consequences of Rad51 overexpression for normal and tumor cells.

The Rad51 recombinase is an essential factor for homologous recombination and the repair of DNA double strand breaks, binding transiently to both single stranded and double stranded DNA during the recombination reaction. The use of a homologous recombination mechanism to repair DNA damage is controlled at several levels, including the binding of Rad51 to single stranded DNA to form the Rad51 nucleofilament, which is controlled through the action of DNA helicases that can counteract nucleofilament formation. Overexpression of Rad51 in different organisms and cell types has a wide assortment of consequences, ranging from increased homologous recombination and increased resistance to DNA damaging agents to disruption of the cell cycle and apoptotic cell death. Rad51 expression is increased in p53-negative cells, and since p53 is often mutated in tumor cells, there is a tendency for Rad51 to be overexpressed in tumor cells, leading to increased resistance to DNA damage and drugs used in chemotherapies. As cells with increased Rad51 levels are more resistant to DNA damage, there is a selection for tumor cells to have higher Rad51 levels. While increased Rad51 can provide drug resistance, it also leads to increased genomic instability and may contribute to carcinogenesis.

2000 - The Journal of Biological Chemistry
Repair of an Interstrand DNA Cross-link Initiated by ERCC1-XPF Repair/Recombination Nuclease*

Interstrand DNA cross-link damage is a severe challenge to genomic integrity. Nucleotide excision repair plays some role in the repair of DNA cross-links caused by psoralens and other agents. However, in mammalian cells there is evidence that the ERCC1-XPF nuclease has a specialized additional function during interstrand DNA cross-link repair, beyond its role in nucleotide excision repair. We placed a psoralen monoadduct or interstrand cross-link in a duplex, 4–6 bases from a junction with unpaired DNA. ERCC1-XPF endonucleolytically cleaved within the duplex on either side of the adduct, on the strand having an unpaired 3′ tail. Cross-links that were cleaved only on the 5′ side were purified and reincubated with ERCC1-XPF. A second cleavage was then observed on the 3′ side. Relevant partially unwound structures near a cross-link may be expected to arise frequently, for example at stalled DNA replication forks. The results show that the single enzyme ERCC1-XPF can release one arm of a cross-link and suggest a novel mechanism for interstrand cross-link repair.

2002 - Journal of Bacteriology
Recognition of DNA by Fur: a Reinterpretation of the Fur Box Consensus Sequence

ABSTRACT Ferric uptake repressor (Fur) proteins regulate the expression of iron homeostasis genes in response to intracellular iron levels. In general, Fur proteins bind with high affinity to a 19-bp inverted repeat sequence known as the Fur box. An alignment of 19 operator sites recognized by Bacillus subtilis Fur revealed a different conserved 15-bp (7-1-7) inverted repeat present twice within this 19-bp consensus sequence. We demonstrated using electrophoretic mobility shift assays that this 7-1-7 inverted repeat comprises a minimal recognition site for high-affinity binding by Fur. The resulting revised consensus sequence is remarkably similar to a related 7-1-7 inverted repeat sequence recognized by PerR, a Fur paralog. Our analysis of the affinity and stoichiometry of DNA binding by B. subtilis Fur, together with a reinterpretation of previously described studies of Escherichia coli Fur, supports a model in which the 19-bp Fur box represents overlapping recognition sites for two Fur dimers bound to opposite faces of the DNA helix. The resulting recognition complex is reminiscent of that observed for the functionally related protein DtxR. Like Fur, DtxR contains a helix-turn-helix DNA-binding motif, recognizes a 19-bp inverted repeat sequence, and has a typical DNase I footprint of ∼30 bp. By envisioning a similar mode of DNA recognition for Fur, we can account for the internal symmetries noted previously within the Fur box, the tendency of Fur to extend into adjacent regions of DNA in a sequence-selective manner, and the observed patterns of DNA protection against enzymatic and chemical probes.

2005 - The Plant journal : for cell and molecular biology
High-frequency homologous recombination in plants mediated by zinc-finger nucleases.

Homologous recombination offers great promise for plant genome engineering. This promise has not been realized, however, because when DNA enters plant cells homologous recombination occurs infrequently and random integration predominates. Using a tobacco test system, we demonstrate that chromosome breaks created by zinc-finger nucleases greatly enhance the frequency of localized recombination. Homologous recombination was measured by restoring function to a defective GUS:NPTII reporter gene integrated at various chromosomal sites in 10 different transgenic tobacco lines. The reporter gene carried a recognition site for a zinc-finger nuclease, and protoplasts from each tobacco line were electroporated with both DNA encoding the nuclease and donor DNA to effect repair of the reporter. Homologous recombination occurred in more than 10% of the transformed protoplasts regardless of the reporter's chromosomal position. Approximately 20% of the GUS:NPTII reporter genes were repaired solely by homologous recombination, whereas the remainder had associated DNA insertions or deletions consistent with repair by both homologous recombination and non-homologous end joining. The DNA-binding domain encoded by zinc-finger nucleases can be engineered to recognize a variety of chromosomal target sequences. This flexibility, coupled with the enhancement in homologous recombination conferred by double-strand breaks, suggests that plant genome engineering through homologous recombination can now be reliably accomplished using zinc-finger nucleases.

2009 - Nature
Principles of ubiquitin and SUMO modifications in DNA repair

With the discovery in the late 1980s that the DNA-repair gene RAD6 encodes a ubiquitin-conjugating enzyme, it became clear that protein modification by ubiquitin conjugation has a much broader significance than had previously been assumed. Now, two decades later, ubiquitin and its cousin SUMO are implicated in a range of human diseases, including breast cancer and Fanconi anaemia, giving fresh momentum to studies focused on the relationships between ubiquitin, SUMO and DNA-repair pathways.

2012 - Science
The Crystal Structure of TAL Effector PthXo1 Bound to Its DNA Target

Wrapped DNA TAL effectors are proteins that bacterial pathogens inject into plant cells that bind to host DNA to activate expression of plant genes. The DNA-binding domain of TAL proteins is composed of tandem repeats within which a repeat-variable diresidue sequence confers nucleotide specificity. Deng et al. (p. 720, published online 5 January) report the structure of the TAL effector dHax3, containing 11.5 repeats, in DNA-free and DNA-bound states, and Mak et al. (p. 716, published online 5 January) report the structure of the PthXo1 TAL effector, containing 22 repeats, bound to its DNA target. Together, the structures reveal the conformational changes involved in DNA binding and provide the structural basis of DNA recognition. Structures show how a virulence factor in a plant pathogen recognizes and binds to host DNA. DNA recognition by TAL effectors is mediated by tandem repeats, each 33 to 35 residues in length, that specify nucleotides via unique repeat-variable diresidues (RVDs). The crystal structure of PthXo1 bound to its DNA target was determined by high-throughput computational structure prediction and validated by heavy-atom derivatization. Each repeat forms a left-handed, two-helix bundle that presents an RVD-containing loop to the DNA. The repeats self-associate to form a right-handed superhelix wrapped around the DNA major groove. The first RVD residue forms a stabilizing contact with the protein backbone, while the second makes a base-specific contact to the DNA sense strand. Two degenerate amino-terminal repeats also interact with the DNA. Containing several RVDs and noncanonical associations, the structure illustrates the basis of TAL effector–DNA recognition.

2007 - Journal of Biological Chemistry
Role of RAD51C and XRCC3 in Genetic Recombination and DNA Repair*

In germ line cells, recombination is required for gene reassortment and proper chromosome segregation at meiosis, whereas in somatic cells it provides an important mechanism for the repair of DNA double-strand breaks. Five proteins (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) that share homology with RAD51 recombinase and are known as the RAD51 paralogs are important for recombinational repair, as paralog-defective cell lines exhibit spontaneous chromosomal aberrations, defective DNA repair, and reduced gene targeting. The paralogs form two distinct protein complexes, RAD51B-RAD51C-RAD51D-XRCC2 and RAD51C-XRCC3, but their precise cellular roles remain unknown. Here, we show that, like MLH1, RAD51C localized to mouse meiotic chromosomes at pachytene/diplotene. Using immunoprecipitation and gel filtration analyses, we found that Holliday junction resolvase activity associated tightly and co-eluted with the 80-kDa RAD51C-XRCC3 complex. Taken together, these data indicate that the RAD51C-XRCC3-associated Holliday junction resolvase complex associates with crossovers and may play an essential role in the resolution of recombination intermediates prior to chromosome segregation.

Insights into DNA recombination from the structure of a RAD51–BRCA2 complex

Tom L. Blundell
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Luca Pellegrini
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Ashok R. Venkitaraman
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T. Blundell
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L. Pellegrini
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A. Venkitaraman
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Thomas Lo
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David S. Yu
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Thomas Lo
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MiYoung Lee
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Shubha Anand
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Miyoung Lee
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Shubha Anand

Abstract:The breast cancer susceptibility protein BRCA2 controls the function of RAD51, a recombinase enzyme, in pathways for DNA repair by homologous recombination. We report here the structure of a complex between an evolutionarily conserved sequence in BRCA2 (the BRC repeat) and the RecA-homology domain of RAD51. The BRC repeat mimics a motif in RAD51 that serves as an interface for oligomerization between individual RAD51 monomers, thus enabling BRCA2 to control the assembly of the RAD51 nucleoprotein filament, which is essential for strand-pairing reactions during DNA recombination. The RAD51 oligomerization motif is highly conserved among RecA-like recombinases, highlighting a common evolutionary origin for the mechanism of nucleoprotein filament formation, mirrored in the BRC repeat. Cancer-associated mutations that affect the BRC repeat disrupt its predicted interaction with RAD51, yielding structural insight into mechanisms for cancer susceptibility.

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引用
Using ONETEP for accurate and efficient density functional calculations
cond-mat/0507450
2005
Design of Potent Inhibitors of Human RAD51 Recombinase Based on BRC Motifs of BRCA2 Protein: Modeling and Experimental Validation of a Chimera Peptide
Journal of medicinal chemistry
2010
Structural basis for substrate binding, cleavage and allostery in the tRNA maturase RNase Z
Nature
2005
Full‐length archaeal Rad51 structure and mutants: mechanisms for RAD51 assembly and control by BRCA2
The EMBO journal
2003
Specificity of Linear Motifs That Bind to a Common Mitogen-Activated Protein Kinase Docking Groove
Science Signaling
2012
Low-dose extrapolation of radiation-related cancer risk.
Annals of the ICRP
2005
BRCA1 and BRCA2: different roles in a common pathway of genome protection
Nature Reviews Cancer
2011
Recombination proteins in yeast.
Annual review of genetics
2004
The Arabidopsis AtRAD51 gene is dispensable for vegetative development but required for meiosis.
Proceedings of the National Academy of Sciences of the United States of America
2004
A mitotic function for the high-mobility group protein HMG20b regulated by its interaction with the BRC repeats of the BRCA2 tumor suppressor
Oncogene
2011
Stabilization of RAD51 nucleoprotein filaments by the C-terminal region of BRCA2
Nature Structural &Molecular Biology
2007
Altered DNA binding by the human Rad51-R150Q mutant found in breast cancer patients.
Biological and Pharmaceutical Bulletin
2007
Domain mapping of the Rad51 paralog protein complexes.
Nucleic acids research
2004
Molecular views of recombination proteins and their control
Nature Reviews Molecular Cell Biology
2003
The role of double-strand break repair — insights from human genetics
Nature Reviews Genetics
2006
Protein mimicry of DNA and pathway regulation.
DNA repair
2005
Development of Synthetic Lethality Anticancer Therapeutics
Journal of medicinal chemistry
2014
Essential Role of BRCA2 in Ovarian Development and Function
The New England journal of medicine
2018
The BRC Repeats of BRCA2 Modulate the DNA-Binding Selectivity of RAD51
Cell
2009
Interrogation of the Protein-Protein Interactions between Human BRCA2 BRC Repeats and RAD51 Reveals Atomistic Determinants of Affinity
PLoS Comput. Biol.
2011