scholarly journals Nucleotide Excision Repair of Chemically Stabilized Analogues of DNA Interstrand Cross-Links Produced from Oxidized Abasic Sites

Biochemistry ◽  
2014 ◽  
Vol 53 (37) ◽  
pp. 5958-5965 ◽  
Author(s):  
Souradyuti Ghosh ◽  
Marc M. Greenberg
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Abasic Sites ◽  
Nucleotide Excision ◽  
Interstrand Cross Links ◽  
Cross Links

scholarly journals Cho Endonuclease Functions during DNA Interstrand Cross-Link Repair in Escherichia coli

2016 ◽  
Vol 198 (22) ◽  
pp. 3099-3108 ◽  
Author(s):  
Anthonige Vidya Perera ◽  
James Brian Mendenhall ◽  
Charmain Tan Courcelle ◽  
Justin Courcelle
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Repair Process ◽  
Differential Sensitivity ◽  
Duplex Dna ◽  
Dna Lesion ◽  
Nucleotide Excision ◽  
Interstrand Cross Links ◽  
Cross Links ◽  
Complex Lesions

ABSTRACTDNA interstrand cross-links are complex lesions that covalently link both strands of the duplex DNA. Lesion removal is proposed to be initiated via the UvrABC nucleotide excision repair complex; however, less is known about the subsequent steps of this complex repair pathway. In this study, we characterized the contribution of nucleotide excision repair mutants to survival in the presence of psoralen-induced damage. Unexpectedly, we observed that the nucleotide excision repair mutants exhibit differential sensitivity to psoralen-induced damage, withuvrCmutants being less sensitive than eitheruvrAoruvrB. We show that Cho, an alternative endonuclease, acts with UvrAB and is responsible for the reduced hypersensitivity ofuvrCmutants. We find that Cho's contribution to survival correlates with the presence of DNA interstrand cross-links, rather than monoadducts, and operates at a step after, or independently from, the initial incision during the global repair of psoralen DNA adducts from the genome.IMPORTANCEDNA interstrand cross-links are complex lesions that covalently bind to both strands of the duplex DNA and whose mechanism of repair remains poorly understood. In this study, we show that Cho, an alternative endonuclease, acts with UvrAB and participates in the repair of DNA interstrand cross-links formed in the presence of photoactivated psoralens. Cho's contribution to survival correlates with the presence of DNA interstrand cross-links and operates at a step after, or independently from, the initial incision during the repair process.

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 Nucleotide Excision Repair- and Polymerase η-Mediated Error-Prone Removal of Mitomycin C Interstrand Cross-Links

2003 ◽  
Vol 23 (2) ◽  
pp. 754-761 ◽  
Author(s):  
Huyong Zheng ◽  
Xin Wang ◽  
Amy J. Warren ◽  
Randy J. Legerski ◽  
Rodney S. Nairn ◽  
...  
Keyword(s):  
Mitomycin C ◽  
Nucleotide Excision Repair ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Double Helix ◽  
Dna Lesions ◽  
Nucleotide Excision ◽  
Interstrand Cross Links ◽  
Cross Links

ABSTRACT Interstrand cross-links (ICLs) make up a unique class of DNA lesions in which both strands of the double helix are covalently joined, precluding strand opening during replication and transcription. The repair of DNA ICLs has become a focus of study since ICLs are recognized as the main cytotoxic lesion inflicted by an array of alkylating compounds used in cancer treatment. As is the case for double-strand breaks, a damage-free homologous copy is essential for the removal of ICLs in an error-free manner. However, recombination-independent mechanisms may exist to remove ICLs in an error-prone fashion. We have developed an in vivo reactivation assay that can be used to examine the removal of site-specific mitomycin C-mediated ICLs in mammalian cells. We found that the removal of the ICL from the reporter substrate could take place in the absence of undamaged homologous sequences in repair-proficient cells, suggesting a cross-link repair mechanism that is independent of homologous recombination. Systematic analysis of nucleotide excision repair mutants demonstrated the involvement of transcription-coupled nucleotide excision repair and a partial requirement for the lesion bypass DNA polymerase η encoded by the human POLH gene. From these observations, we propose the existence of a recombination-independent and mutagenic repair pathway for the removal of ICLs in mammalian cells.

scholarly journals hMutSβ Is Required for the Recognition and Uncoupling of Psoralen Interstrand Cross-Links In Vitro

2002 ◽  
Vol 22 (7) ◽  
pp. 2388-2397 ◽  
Author(s):  
Nianxiang Zhang ◽  
Xiaoyan Lu ◽  
Xiaoshan Zhang ◽  
Carolyn A. Peterson ◽  
Randy J. Legerski
Keyword(s):  
Mismatch Repair ◽  
Nucleotide Excision Repair ◽  
Mammalian Cell ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Cell Extracts ◽  
Nucleotide Excision ◽  
Interstrand Cross Links ◽  
Cross Links

ABSTRACT The removal of interstrand cross-links (ICLs) from DNA in higher eucaryotes is not well understood. Here, we show that processing of psoralen ICLs in mammalian cell extracts is dependent upon the mismatch repair complex hMutSβ but is not dependent upon the hMutSα complex or hMlh1. The processing of psoralen ICLs is also dependent upon the nucleotide excision repair proteins Ercc1 and Xpf but not upon other components of the excision stage of this pathway or upon Fanconi anemia proteins. Products formed during the in vitro reaction indicated that the ICL has been removed or uncoupled from the cross-linked substrate in the mammalian cell extracts. Finally, the hMutSβ complex is shown to specifically bind to psoralen ICLs, and this binding is stimulated by the addition of PCNA. Thus, a novel pathway for processing ICLs has been identified in mammalian cells which involves components of the mismatch repair and nucleotide excision repair pathways.

scholarly journals Abasic Sites in the Transcribed Strand of Yeast DNA Are Removed by Transcription-Coupled Nucleotide Excision Repair

2010 ◽  
Vol 30 (13) ◽  
pp. 3206-3215 ◽  
Author(s):  
Nayun Kim ◽  
Sue Jinks-Robertson
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Genome Integrity ◽  
Genetic Studies ◽  
Abasic Sites ◽  
Dna And Rna ◽  
Nucleotide Excision ◽  
Ap Sites ◽  
Base Excision ◽  
Ap Site

ABSTRACT Abasic (AP) sites are potent blocks to DNA and RNA polymerases, and their repair is essential for maintaining genome integrity. Although AP sites are efficiently dealt with through the base excision repair (BER) pathway, genetic studies suggest that repair also can occur via nucleotide excision repair (NER). The involvement of NER in AP-site removal has been puzzling, however, as this pathway is thought to target only bulky lesions. Here, we examine the repair of AP sites generated when uracil is removed from a highly transcribed gene in yeast. Because uracil is incorporated instead of thymine under these conditions, the position of the resulting AP site is known. Results demonstrate that only AP sites on the transcribed strand are efficient substrates for NER, suggesting the recruitment of the NER machinery by an AP-blocked RNA polymerase. Such transcription-coupled NER of AP sites may explain previously suggested links between the BER pathway and transcription.

scholarly journals Evidence for the Involvement of Nucleotide Excision Repair in the Removal of Abasic Sites in Yeast

2000 ◽  
Vol 20 (10) ◽  
pp. 3522-3528 ◽  
Author(s):  
Carlos A. Torres-Ramos ◽  
Robert E. Johnson ◽  
Louise Prakash ◽  
Satya Prakash
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Repair Process ◽  
Dna Glycosylases ◽  
Abasic Sites ◽  
Skin Cancers ◽  
Nucleotide Excision ◽  
Progressive Neurodegeneration ◽  
Ap Sites ◽  
Base Excision

ABSTRACT In eukaryotes, DNA damage induced by ultraviolet light and other agents which distort the helix is removed by nucleotide excision repair (NER) in a fragment ∼25 to 30 nucleotides long. In humans, a deficiency in NER causes xeroderma pigmentosum (XP), characterized by extreme sensitivity to sunlight and a high incidence of skin cancers. Abasic (AP) sites are formed in DNA as a result of spontaneous base loss and from the action of DNA glycosylases involved in base excision repair. In Saccharomyces cerevisiae, AP sites are removed via the action of two class II AP endonucleases, Apn1 and Apn2. Here, we provide evidence for the involvement of NER in the removal of AP sites and show that NER competes with Apn1 and Apn2 in this repair process. Inactivation of NER in the apn1Δ orapn1Δ apn2Δ strain enhances sensitivity to the monofunctional alkylating agent methyl methanesulfonate and leads to further impairment in the cellular ability to remove AP sites. A deficiency in the repair of AP sites may contribute to the internal cancers and progressive neurodegeneration that occur in XP patients.

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