Causes and consequences of DNA single-strand breaks

Trends in Biochemical Sciences, Год журнала: 2023, Номер 49(1), С. 68 - 78

Опубликована: Ноя. 30, 2023

DNA single-strand breaks (SSBs) are among the most common lesions arising in human cells, with tens to hundreds of thousands each cell, day. Cells have efficient mechanisms for sensing and repair these ubiquitous lesions, but failure processes rapidly remove SSBs can lead a variety pathogenic outcomes. The threat posed by unrepaired is illustrated existence at least six genetic diseases which SSB (SSBR) defective, all characterised neurodevelopmental and/or neurodegenerative pathology. Here, I review current understanding how arise impact on critical molecular processes, such as replication gene transcription, their links disease.

Язык: Английский

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Prime Editing: Mechanistic Insights and DNA Repair Modulation

Cells, Год журнала: 2025, Номер 14(4), С. 277 - 277

Опубликована: Фев. 13, 2025

Prime editing is a genome technique that allows precise modifications of cellular DNA without relying on donor templates. Recently, several different prime editor proteins have been published in the literature, single- or double-strand breaks. When occurs, undergoes one repair pathways, and these processes can be modulated with use inhibitors. Firstly, this review provides an overview mechanisms their modulation by known In addition, we summarize editors provide comprehensive associated mechanisms. Finally, discuss delivery safety aspects editing.

Язык: Английский

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A Rfa1-MN–based system reveals new factors involved in the rescue of broken replication forks

PLoS Genetics, Год журнала: 2025, Номер 21(4), С. e1011405 - e1011405

Опубликована: Апрель 1, 2025

The integrity of the replication forks is essential for an accurate and timely completion genome duplication. However, little known about how cells deal with broken forks. We have generated in yeast a system based on chimera largest subunit ssDNA binding complex RPA fused to micrococcal nuclease (Rfa1-MN) induce double-strand breaks (DSBs) at searched mutants affected their repair. Our results show that core homologous recombination (HR) proteins involved formation ssDNA/Rad51 filament are repair DSBs forks, whereas non-homologous end joining plays no role. Apart from endonucleases Mus81 Yen1, process employs fork-associated HR factors, break-induced (BIR)-associated factors replisome components sister chromatid cohesion fork stability, pointing restart by BIR followed restoration. Notably, we also found controlling length G1, suggesting minimal number active origins facilitates converging study has revealed requirement checkpoint functions, including synthesis Dun1-mediated dNTPs. Finally, our screening impact loss chromatin partially disassembled nucleosome structure accessibility machinery. In conclusion, this provides overview mechanisms cooperate

Язык: Английский

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Cell Type Specific Suppression of Hyper-Recombination by Human RAD18 Is Linked to Proliferating Cell Nuclear Antigen K164 Ubiquitination

Biomolecules, Год журнала: 2025, Номер 15(1), С. 150 - 150

Опубликована: Янв. 20, 2025

RAD18 is a conserved eukaryotic E3 ubiquitin ligase that promotes genome stability through multiple pathways. One of these gap-filling DNA synthesis at active replication forks and in post-replicative DNA. also regulates homologous recombination (HR) repair breaks; however, the current literature describing contribution to HR mammalian systems has not reached consensus. To investigate this, we examined three independent RAD18-null human cell lines. Our analyses found loss HCT116, but neither hTERT RPE-1 nor DLD1 lines, resulted elevated sister chromatid exchange, gene conversion, targeting, i.e., HCT116 mutants were hyper-recombinogenic (hyper-rec). Interestingly, phenotypes linked RAD18’s role PCNA K164 ubiquitination, as PCNAK164R/+ hyper-rec, consistent with previous studies rad18−/− pcnaK164R avian DT40 cells. Importantly, knockdown UBC9 prevent SUMOylation did affect hyper-recombination, strengthening link between increased RAD18-catalyzed SUMOylation. We propose hierarchy HR, intrinsic each type, dictates whether required for suppression hyper-recombination this function ubiquitination.

Язык: Английский

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Exploration of poly (ADP‐ribose) polymerase inhibitor resistance in the treatment of BRCA1/2‐mutated cancer

Genes Chromosomes and Cancer, Год журнала: 2024, Номер 63(5)

Опубликована: Май 1, 2024

Breast cancer susceptibility 1/2 (BRCA1/2) genes play a crucial role in DNA damage repair, yet mutations these increase the to tumorigenesis. Exploiting synthetic lethality mechanism between BRCA1/2 and poly(ADP-ribose) polymerase (PARP) inhibition has led development clinical approval of PARP inhibitor (PARPi), representing milestone targeted therapy for mutant tumors. This approach paved way leveraging tumor treatment strategies. Despite initial success PARPis, resistance agents diminishes their efficacy BRCA1/2-mutant Investigations into PARPi have identified replication fork stability homologous recombination repair as key factors sensitive PARPis. Additionally, studies suggest that gaps may also confer sensitivity Moreover, emerging evidence indicates correlation cisplatin resistance, suggesting potential overlap mechanisms underlying both agents. Given findings, it is imperative explore interplay particularly context platinum resistance. Understanding impact on offer insights novel therapeutic strategies overcome enhance therapies

Язык: Английский

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Protein Assemblies in Translesion Synthesis

Genes, Год журнала: 2024, Номер 15(7), С. 832 - 832

Опубликована: Июнь 24, 2024

Translesion synthesis (TLS) is a mechanism of DNA damage tolerance utilized by eukaryotic cells to replicate across lesions that impede the high-fidelity replication machinery. In TLS, series specialized polymerases are employed, which recognize specific lesions, insert nucleotides damage, and extend distorted primer-template. This allows preserve genetic integrity at cost mutations. humans, TLS enzymes include Y-family, inserter polymerases, Polη, Polι, Polκ, Rev1, B-family extender polymerase Polζ, while in S. cerevisiae only Polζ present. To bypass cooperate, assembling into complex on sliding clamp, PCNA, termed mutasome. The mutasome assembly contingent protein–protein interactions (PPIs) between modular domains subunits enzymes, their with PCNA DNA. While structural mechanisms lesion PPIs individual modules well understood, they cooperate context complexes have remained elusive. review focuses studies describes case holoenzyme assemblies action emerging from recent high-resolution Cryo-EM studies.

Язык: Английский

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Tolerating DNA damage by repriming: Gap filling in the spotlight

DNA repair, Год журнала: 2024, Номер 142, С. 103758 - 103758

Опубликована: Авг. 30, 2024

Timely and accurate DNA replication is critical for safeguarding genome integrity ensuring cell viability. Yet, this process challenged by damage blocking the progression of machinery. To counteract fork stalling, evolutionary conserved tolerance (DDT) mechanisms promote bypass movement. One these involves "skipping" through repriming downstream lesion, leaving single-stranded (ssDNA) gaps behind advancing forks (also known as post-replicative gaps). In vertebrates, in damaged leading templates proposed to be mainly promoted primase polymerase PRIMPOL. review, we discuss recent advances towards our understanding physiological pathological conditions activation human models, revealing a regulatory network PRIMPOL activity. Upon PRIMPOL, formed can filled-in DDT translesion synthesis template switching. We novel findings on how are regulated coordinated time gap filling. Finally, defective filling aberrant expansion nucleases underlie cytotoxicity associated with accumulation. Our increasing knowledge mechanism - from formation that targeting last step pathway promising approach exploit anti-cancer therapeutic strategies.

Язык: Английский

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Molecular identification of a peroxidase gene controlling body size in the entomopathogenic nematode Steinernema hermaphroditum

Genetics, Год журнала: 2023, Номер 226(2)

Опубликована: Дек. 11, 2023

The entomopathogenic nematode Steinernema hermaphroditum was recently rediscovered and is being developed as a genetically tractable experimental system for the study of previously unexplored biology, including parasitism its insect hosts mutualism with bacterial endosymbiont Xenorhabdus griffiniae. Through whole-genome re-sequencing genetic mapping we have first time molecularly identified gene responsible mutationally defined phenotypic locus in an nematode. In process observed unexpected mutational spectrum following ethyl methansulfonate mutagenesis this species. We find that ortholog essential Caenorhabditis elegans peroxidase skpo-2 controls body size shape S. hermaphroditum. confirmed identification by generating additional loss-of-function mutations using CRISPR-Cas9. propose will accelerate targeting other nematodes used commercially pest control, X-linked males hemizygous loss function can mate, making easily recognized maintained marker use co-CRISPR.

Язык: Английский

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PARP10 promotes the repair of nascent strand DNA gaps through RAD18 mediated translesion synthesis

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июль 23, 2024

Abstract Replication stress compromises genomic integrity. Fork blocking lesions such as those induced by cisplatin and other chemotherapeutic agents arrest replication forks. Repriming downstream of these represents an important mechanism restart, however the single stranded DNA (ssDNA) gaps left behind, unless efficiently filled, can serve entry point for nucleases. Nascent strand be repaired BRCA-mediated homology repair. Alternatively, also filled translesion synthesis (TLS) polymerases. How events are regulated is still not clear. Here, we show that PARP10, a poorly-characterized mono-ADP-ribosyltransferase, recruited to nascent promote their PARP10 interacts with ubiquitin ligase RAD18 recruits it structures, resulting in ubiquitination factor PCNA. PCNA ubiquitination, turn, TLS polymerase REV1 gap filling. We recruitment subsequent REV1-mediated filling requires both catalytic activity its ability interact moreover hyperactive BRCA-deficient cells, inactivation potentiates accumulations cytotoxicity cells. Our work uncovers regulator ssDNA filling, which promotes stability

Язык: Английский

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PARG inhibitor sensitivity correlates with accumulation of single-stranded DNA gaps in preclinical models of ovarian cancer

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(47)

Опубликована: Ноя. 15, 2024

Poly (ADP-ribose) glycohydrolase (PARG) is a dePARylating enzyme which promotes DNA repair by removal of poly (PAR) from PARylated proteins. Loss or inhibition PARG results in replication stress and sensitizes cancer cells to DNA-damaging agents. inhibitors are now undergoing clinical development for patients having tumors with homologous recombination deficiency (HRD), such as germline somatic

Язык: Английский

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