Homozygous germ line mutation in exon 27 of murineBrca2 disrupts the Fancd2-Brca2 pathway in the homologous recombination-mediated DNA interstrand cross-links' repair but does not affect meiosis

2005 ◽  
Vol 44 (4) ◽  
pp. 429-437 ◽  
Author(s):  
Boyko S. Atanassov ◽  
J. Carl Barrett ◽  
Barbara J. Davis
Keyword(s):  
Homologous Recombination ◽  
Germ Line ◽  
Interstrand Cross Links ◽  
Cross Links ◽  
Germ Line Mutation

scholarly journals The Structure-Specific Endonuclease Ercc1-Xpf Is Required To Resolve DNA Interstrand Cross-Link-Induced Double-Strand Breaks

2004 ◽  
Vol 24 (13) ◽  
pp. 5776-5787 ◽  
Author(s):  
Laura J. Niedernhofer ◽  
Hanny Odijk ◽  
Magda Budzowska ◽  
Ellen van Drunen ◽  
Alex Maas ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Mammalian Cells ◽  
Cell Cycle Progression ◽  
Strand Break ◽  
Sister Chromatid Exchanges ◽  
Wild Type ◽  
Cross Link ◽  
Interstrand Cross Links ◽  
Normal Metabolism ◽  
Cross Links

ABSTRACT Interstrand cross-links (ICLs) are an extremely toxic class of DNA damage incurred during normal metabolism or cancer chemotherapy. ICLs covalently tether both strands of duplex DNA, preventing the strand unwinding that is essential for polymerase access. The mechanism of ICL repair in mammalian cells is poorly understood. However, genetic data implicate the Ercc1-Xpf endonuclease and proteins required for homologous recombination-mediated double-strand break (DSB) repair. To examine the role of Ercc1-Xpf in ICL repair, we monitored the phosphorylation of histone variant H2AX (γ-H2AX). The phosphoprotein accumulates at DSBs, forming foci that can be detected by immunostaining. Treatment of wild-type cells with mitomycin C (MMC) induced γ-H2AX foci and increased the amount of DSBs detected by pulsed-field gel electrophoresis. Surprisingly, γ-H2AX foci were also induced in Ercc1 −/− cells by MMC treatment. Thus, DSBs occur after cross-link damage via an Ercc1-independent mechanism. Instead, ICL-induced DSB formation required cell cycle progression into S phase, suggesting that DSBs are an intermediate of ICL repair that form during DNA replication. In Ercc1 −/− cells, MMC-induced γ-H2AX foci persisted at least 48 h longer than in wild-type cells, demonstrating that Ercc1 is required for the resolution of cross-link-induced DSBs. MMC triggered sister chromatid exchanges in wild-type cells but chromatid fusions in Ercc1 −/− and Xpf mutant cells, indicating that in their absence, repair of DSBs is prevented. Collectively, these data support a role for Ercc1-Xpf in processing ICL-induced DSBs so that these cytotoxic intermediates can be repaired by homologous recombination.

scholarly journals Involvement of Nucleotide Excision Repair in a Recombination-Independent and Error-Prone Pathway of DNA Interstrand Cross-Link Repair

2001 ◽  
Vol 21 (3) ◽  
pp. 713-720 ◽  
Author(s):  
Xin Wang ◽  
Carolyn A. Peterson ◽  
Huyong Zheng ◽  
Rodney S. Nairn ◽  
Randy J. Legerski ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Nucleotide Excision Repair ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Excision Repair ◽  
Repair Pathway ◽  
Cross Link ◽  
Nucleotide Excision ◽  
Interstrand Cross Links ◽  
Cross Links

ABSTRACT DNA interstrand cross-links (ICLs) block the strand separation necessary for essential DNA functions such as transcription and replication and, hence, represent an important class of DNA lesion. Since both strands of the double helix are affected in cross-linked DNA, it is likely that conservative recombination using undamaged homologous regions as a donor may be required to repair ICLs in an error-free manner. However, in Escherichia coli and yeast, recombination-independent mechanisms of ICL repair have been identified in addition to recombinational repair pathways. To study the repair mechanisms of interstrand cross-links in mammalian cells, we developed an in vivo reactivation assay to examine the removal of interstrand cross-links in cultured cells. A site-specific psoralen cross-link was placed between the promoter and the coding region to inactivate the expression of green fluorescent protein or luciferase genes from reporter plasmids. By monitoring the reactivation of the reporter gene, we showed that a single defined psoralen cross-link was removed in repair-proficient cells in the absence of undamaged homologous sequences, suggesting the existence of an ICL repair pathway that is independent of homologous recombination. Mutant cell lines deficient in the nucleotide excision repair pathway were examined and found to be highly defective in the recombination-independent repair of ICLs, while mutants deficient in homologous recombination were found to be proficient. Mutation analysis of plasmids recovered from transfected cells showed frequent base substitutions at or near positions opposing a cross-linked thymidine residue. Based on these results, we suggest a distinct pathway for DNA interstrand cross-link repair involving nucleotide excision repair and a putative lesion bypass mechanism.

scholarly journals XPF-ERCC1 Participates in the Fanconi Anemia Pathway of Cross-Link Repair

2009 ◽  
Vol 29 (24) ◽  
pp. 6427-6437 ◽  
Author(s):  
Nikhil Bhagwat ◽  
Anna L. Olsen ◽  
Anderson T. Wang ◽  
Katsuhiro Hanada ◽  
Patricia Stuckert ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Fanconi Anemia ◽  
Dna Double Strand Breaks ◽  
Fanconi Anemia Pathway ◽  
Strand Breaks ◽  
Interstrand Cross Links ◽  
Mammalian Genomes ◽  
Cross Links ◽  
Dna Strand ◽  
Transcription And Replication

ABSTRACT Interstrand cross-links (ICLs) prevent DNA strand separation and, therefore, transcription and replication, making them extremely cytotoxic. The precise mechanism by which ICLs are removed from mammalian genomes largely remains elusive. Genetic evidence implicates ATR, the Fanconi anemia proteins, proteins required for homologous recombination, translesion synthesis, and at least two endonucleases, MUS81-EME1 and XPF-ERCC1. ICLs cause replication-dependent DNA double-strand breaks (DSBs), and MUS81-EME1 facilitates DSB formation. The subsequent repair of these DSBs occurs via homologous recombination after the ICL is unhooked by XPF-ERCC1. Here, we examined the effect of the loss of either nuclease on FANCD2 monoubiquitination to determine if the nucleolytic processing of ICLs is required for the activation of the Fanconi anemia pathway. FANCD2 was monoubiquitinated in Mus81 −/−, Ercc1 −/−, and XPF-deficient human, mouse, and hamster cells exposed to cross-linking agents. However, the monoubiquitinated form of FANCD2 persisted longer in XPF-ERCC1-deficient cells than in wild-type cells. Moreover, the levels of chromatin-bound FANCD2 were dramatically reduced and the number of ICL-induced FANCD2 foci significantly lower in XPF-ERCC1-deficient cells. These data demonstrate that the unhooking of an ICL by XPF-ERCC1 is necessary for the stable localization of FANCD2 to the chromatin and subsequent homologous recombination-mediated DSB repair.

scholarly journals DNA Interstrand Cross-Link Repair in the Saccharomyces cerevisiae Cell Cycle: Overlapping Roles for PSO2 (SNM1) with MutS Factors and EXO1 during S Phase

2005 ◽  
Vol 25 (6) ◽  
pp. 2297-2309 ◽  
Author(s):  
Louise J. Barber ◽  
Thomas A. Ward ◽  
John A. Hartley ◽  
Peter J. McHugh
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Homologous Recombination ◽  
S Phase ◽  
Cycle Phase ◽  
Dna Double Strand Breaks ◽  
Recombination Rates ◽  
Strand Breaks ◽  
Interstrand Cross Links ◽  
Cross Links

ABSTRACT Pso2/Snm1 is a member of the β-CASP metallo-β-lactamase family of proteins that include the V(D)J recombination factor Artemis. Saccharomyces cerevisiae pso2 mutants are specifically sensitive to agents that induce DNA interstrand cross-links (ICLs). Here we establish a novel overlapping function for PSO2 with MutS mismatch repair factors and the 5′-3′ exonuclease Exo1 in the repair of DNA ICLs, which is confined to S phase. Our data demonstrate a requirement for NER and Pso2, or Exo1 and MutS factors, in the processing of ICLs, and this is required prior to the repair of ICL-induced DNA double-strand breaks (DSBs) that form during replication. Using a chromosomally integrated inverted-repeat substrate, we also show that loss of both pso2 and exo1/msh2 reduces spontaneous homologous recombination rates. Therefore, PSO2, EXO1, and MSH2 also appear to have overlapping roles in the processing of some forms of endogenous DNA damage that occur at an irreversibly collapsed replication fork. Significantly, our analysis of ICL repair in cells synchronized for each cell cycle phase has revealed that homologous recombination does not play a major role in the direct repair of ICLs, even in G2, when a suitable template is readily available. Rather, we propose that recombination is primarily involved in the repair of DSBs that arise from the collapse of replication forks at ICLs. These findings have led to considerable clarification of the complex genetic relationship between various ICL repair pathways.

Mechanism and significance of chromosome damage repair by homologous recombination

2020 ◽  
Vol 64 (5) ◽  
pp. 779-790 ◽  
Author(s):  
Ajinkya S. Kawale ◽  
Patrick Sung
Keyword(s):  
Homologous Recombination ◽  
Meiotic Chromosome ◽  
Accelerated Aging ◽  
Telomere Maintenance ◽  
Chromosome Damage ◽  
Dna Double Strand Breaks ◽  
Damage Repair ◽  
Interstrand Cross Links ◽  
Cross Links ◽  
Prostate Cancers

Abstract Homologous recombination (HR) is a major, conserved pathway of chromosome damage repair. It not only fulfills key functions in the removal of deleterious lesions such as DNA double-strand breaks (DSBs) and interstrand cross-links (ICLs), but also in replication fork repair and protection. Several familial and acquired cancer predisposition syndromes stem from defects in HR. In particular, individuals with mutations in HR genes exhibit predisposition to breast, ovarian, pancreatic, and prostate cancers, and they also show signs of accelerated aging. However, aberrant and untimely HR events can lead to the loss of heterozygosity, genomic rearrangements, and cytotoxic nucleoprotein intermediates. Thus, it is critically important that HR be tightly regulated. In addition to DNA repair, HR is also involved in meiotic chromosome segregation and telomere maintenance in cells that lack telomerase. In this review, we focus on the role of HR in DSB repair (DSBR) and summarize the current state of the field.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

scholarly journals Germ-line Mutation Analysis in Patients with von Hippel-Lindau Disease in Japan: An Extended Study of 77 Families

2000 ◽  
Vol 91 (2) ◽  
pp. 204-212 ◽  
Author(s):  
Minoru Yoshida ◽  
Shingo Ashida ◽  
Keiichi Kondo ◽  
Kazuki Kobayashi ◽  
Hiroshi Kanno ◽  
...  
Keyword(s):  
Mutation Analysis ◽  
Germ Line ◽  
Extended Study ◽  
Von Hippel Lindau ◽  
Von Hippel Lindau Disease ◽  
Germ Line Mutation

scholarly journals Unsuccessful attempt at gene-editing by homologous recombination in the zebrafish germ line using the approach of “Rong and Golic”

2012 ◽  
Vol 21 (5) ◽  
pp. 1125-1136 ◽  
Author(s):  
Rosalind Brookfield ◽  
Felix Dafhnis-Calas ◽  
Zhengyao Xu ◽  
William Brown
Keyword(s):  
Homologous Recombination ◽  
Gene Editing ◽  
Germ Line ◽  
Unsuccessful Attempt
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