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.

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 Nucleotide excision repair of abasic DNA lesions

2019 ◽  
Vol 47 (16) ◽  
pp. 8537-8547 ◽  
Author(s):  
Nataliya Kitsera ◽  
Marta Rodriguez-Alvarez ◽  
Steffen Emmert ◽  
Thomas Carell ◽  
Andriy Khobta
Keyword(s):  
Nucleotide Excision Repair ◽  
Excision Repair ◽  
Dna Lesions ◽  
Transcription Rate ◽  
Repair Pathway ◽  
Nucleotide Excision ◽  
Repair Mechanisms ◽  
Nucleotide Excision Repair Pathway ◽  
Ap Sites ◽  
Base Excision

AbstractApurinic/apyrimidinic (AP) sites are a class of highly mutagenic and toxic DNA lesions arising in the genome from a number of exogenous and endogenous sources. Repair of AP lesions takes place predominantly by the base excision pathway (BER). However, among chemically heterogeneous AP lesions formed in DNA, some are resistant to the endonuclease APE1 and thus refractory to BER. Here, we employed two types of reporter constructs accommodating synthetic APE1-resistant AP lesions to investigate the auxiliary repair mechanisms in human cells. By combined analyses of recovery of the transcription rate and suppression of transcriptional mutagenesis at specifically positioned AP lesions, we demonstrate that nucleotide excision repair pathway (NER) efficiently removes BER-resistant AP lesions and significantly enhances the repair of APE1-sensitive ones. Our results further indicate that core NER components XPA and XPF are equally required and that both global genome (GG-NER) and transcription coupled (TC-NER) subpathways contribute to the repair.

DNA base excision repair and nucleotide excision repair proteins in malignant salivary gland tumors

2021 ◽  
Vol 121 ◽  
pp. 104987
Author(s):  
Fernanda Aragão Felix ◽  
Leorik Pereira da Silva ◽  
Maria Luiza Diniz de Sousa Lopes ◽  
Ana Paula Veras Sobral ◽  
Roseana de Almeida Freitas ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Nucleotide Excision Repair ◽  
Base Excision Repair ◽  
Excision Repair ◽  
Salivary Gland Tumors ◽  
Dna Base Excision Repair ◽  
Dna Base ◽  
Nucleotide Excision ◽  
Base Excision ◽  
Malignant Salivary Gland Tumors

scholarly journals The involvement of nucleotide excision repair proteins in the removal of oxidative DNA damage

2020 ◽  
Vol 48 (20) ◽  
pp. 11227-11243 ◽  
Author(s):  
Namrata Kumar ◽  
Sripriya Raja ◽  
Bennett Van Houten
Keyword(s):  
Nucleotide Excision Repair ◽  
Base Excision Repair ◽  
Oxidative Dna Damage ◽  
Excision Repair ◽  
Base Damage ◽  
The Past ◽  
Nucleotide Excision ◽  
Oxidative Processes ◽  
Repair Pathways ◽  
Base Excision

Abstract The six major mammalian DNA repair pathways were discovered as independent processes, each dedicated to remove specific types of lesions, but the past two decades have brought into focus the significant interplay between these pathways. In particular, several studies have demonstrated that certain proteins of the nucleotide excision repair (NER) and base excision repair (BER) pathways work in a cooperative manner in the removal of oxidative lesions. This review focuses on recent data showing how the NER proteins, XPA, XPC, XPG, CSA, CSB and UV-DDB, work to stimulate known glycosylases involved in the removal of certain forms of base damage resulting from oxidative processes, and also discusses how some oxidative lesions are probably directly repaired through NER. Finally, since many glycosylases are inhibited from working on damage in the context of chromatin, we detail how we believe UV-DDB may be the first responder in altering the structure of damage containing-nucleosomes, allowing access to BER enzymes.

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