3,214 results match your criteria non-homologous joining


Analysis of the light regulatory mechanism in carotenoid production in Rhodosporidium toruloides NBRC 10032.

Biosci Biotechnol Biochem 2021 Jun 14. Epub 2021 Jun 14.

Department of Bioengineering, Nagaoka University of Technology, Niigata, Japan.

Light stimulates carotenoid production in an oleaginous yeast Rhodosporidium toruloides NBRC 10032 by promoting carotenoid biosynthesis genes. These genes undergo two-step of transcriptional activation. The potential light regulator, Cryptochrome DASH (CRY1), has been suggested to contribute to this mechanism. Read More

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Phosphorylation of TRIP13 at Y56 induces Radiation Resistance but Sensitizes Head and Neck Cancer to Cetuximab.

Mol Ther 2021 Jun 7. Epub 2021 Jun 7.

Department of Periodontics and Oral Medicine, School of Dentistry; Pathology, Medical School. Electronic address:

Radiation therapy, a mainstay of treatment for head and neck cancer, is not always curative due to the development of treatment resistance; additionally, multi-institutional trials have questioned the efficacy of concurrent radiation with cetuximab, the EGFR inhibitor. We unraveled a mechanism for radiation resistance; radiation induces EGFR, which phosphorylates TRIP13 on tyrosine 56. Phospho-TRIP13 promotes non-homologous end joining (NHEJ) repair to induce radiation resistance. Read More

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DNA-PK inhibitor peposertib enhances p53-dependent cytotoxicity of DNA double-strand break inducing therapy in acute leukemia.

Sci Rep 2021 Jun 9;11(1):12148. Epub 2021 Jun 9.

Translational Innovation Platform Oncology and Immuno-Oncology, EMD Serono Research & Development Institute, Inc, Billerica, MA, USA.

Peposertib (M3814) is a potent and selective DNA-PK inhibitor in early clinical development. It effectively blocks non-homologous end-joining repair of DNA double-strand breaks (DSB) and strongly potentiates the antitumor effect of ionizing radiation (IR) and topoisomerase II inhibitors. By suppressing DNA-PK catalytic activity in the presence of DNA DSB, M3814 potentiates ATM/p53 signaling leading to enhanced p53-dependent antitumor activity in tumor cells. Read More

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High-fidelity, efficient, and reversible labeling of endogenous proteins using CRISPR-based designer exon insertion.

Elife 2021 Jun 8;10. Epub 2021 Jun 8.

Vollum Institute, Oregon Health & Science University, Portland, United States.

Precise and efficient insertion of large DNA fragments into somatic cells using gene editing technologies to label or modify endogenous proteins remains challenging. Non-specific insertions/deletions (INDELs) resulting from the non-homologous end joining pathway make the process error-prone. Further, the insert is not readily removable. Read More

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Aging and oxidative stress alter DNA repair mechanisms in male germ cells of superoxide dismutase-1 null mice.

Biol Reprod 2021 Jun 7. Epub 2021 Jun 7.

Department of Obstetrics & Gynecology, McGill University, Montreal, Quebec, Canada.

The efficiency of antioxidant defense system decreases with aging, thus resulting in high levels of reactive oxygen species (ROS) and DNA damage in spermatozoa. This damage can lead to genetic disorders in the offspring. There are limited studies investigating the effects of the total loss of antioxidants, such as superoxide dismutase-1 (SOD1), in male germ cells as they progress through spermatogenesis. Read More

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IGF-1R depletion sensitizes colon cancer cell lines to radiotherapy.

Cancer Biomark 2021 Jun 5. Epub 2021 Jun 5.

Department of Oncology, MianYang Central Hospital, MianYang, Sichuan, China.

Purpose: Insulin like growth factor receptor 1 (IGF-1R) has been documented to play a key role in radiation response, thereby offering an attractive drug target to enhance tumor sensitivity to radiotherapy. Here, we investigated weather knockdown of IGF-1R can sensitize colorectal cancer (CRC) cell lines to radiation.

Material And Methods: Human colon carcinoma SW480 and HT-29 cells were transfected with specific small interference RNA (siRNA) to mediate IGF-1R depletion. Read More

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Histone methylation can either promote or reduce cellular radiosensitivity by regulating DNA repair pathways.

Mutat Res 2021 Jan-Jun;787:108362. Epub 2020 Dec 13.

Institute of Radiation Medicine, Shanghai Medical College, Fudan University, No. 2094 Xie-Tu Road, Shanghai, 200032, China. Electronic address:

Radiotherapy is one of the primary modalities for cancer treatment, and its efficiency usually relies on cellular radiosensitivity. DNA damage repair is a core content of cellular radiosensitivity, and the primary mechanism of which includes non-homologous end-joining (NHEJ) and homologous recombination (HR). By affecting DNA damage repair, histone methylation regulated by histone methyltransferases (HMTs) and histone demethylases (HDMs) participates in the regulation of cellular radiosensitivity via three mechanisms: (a) recruiting DNA repair-related proteins, (b) regulating the expressions of DNA repair genes, and (c) mediating the dynamic change of chromatin. Read More

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December 2020

Genome downsizing after polyploidy: mechanisms, rates and selection pressures.

Plant J 2021 Jun 2. Epub 2021 Jun 2.

Queen Mary University of London, Mile End Road, London, E1 4NS, UK.

An analysis of over 10,000 plant genome sizes (GS) indicate that most species have smaller genomes than expected given the incidence of polyploidy in their ancestries, suggesting selection for genome downsizing. However, comparing ancestral GS with the incidence of ancestral polyploidy suggests that the rate of DNA loss following polyploidy is likely to have been very small (4-70 Mb/million years, 4-482 bp/generation). This poses a problem, how might such small DNA losses be visible to selection, overcome the power of genetic drift, and drive genome downsizing? We explore that problem, focusing on the role that double-strand break (DSB) repair pathways (non-homologous end joining (NHEJ) and homologous recombination (HR)) may have played. Read More

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Mechanistic Modelling of Slow and Fast NHEJ DNA Repair Pathways Following Radiation for G0/G1 Normal Tissue Cells.

Cancers (Basel) 2021 May 3;13(9). Epub 2021 May 3.

Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK.

Mechanistic in silico models can provide insight into biological mechanisms and highlight uncertainties for experimental investigation. Radiation-induced double-strand breaks (DSBs) are known to be toxic lesions if not repaired correctly. Non-homologous end joining (NHEJ) is the major DSB-repair pathway available throughout the cell cycle and, recently, has been hypothesised to consist of a fast and slow component in G0/G1. Read More

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X-ray scattering reveals disordered linkers and dynamic interfaces in complexes and mechanisms for DNA double-strand break repair impacting cell and cancer biology.

Protein Sci 2021 May 30. Epub 2021 May 30.

Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, USA.

Evolutionary selection ensures specificity and efficiency in dynamic metastable macromolecular machines that repair DNA damage without releasing toxic and mutagenic intermediates. Here we examine non-homologous end joining (NHEJ) as the primary conserved DNA double-strand break (DSB) repair process in human cells. NHEJ has exemplary key roles in networks determining the development, outcome of cancer treatments by DSB-inducing agents, generation of antibody and T-cell receptor diversity, and innate immune response for RNA viruses. Read More

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Radiotherapy is associated with a deletion signature that contributes to poor outcomes in patients with cancer.

Nat Genet 2021 May 27. Epub 2021 May 27.

The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA.

Ionizing radiation causes DNA damage and is a mainstay for cancer treatment, but understanding of its genomic impact is limited. We analyzed mutational spectra following radiotherapy in 190 paired primary and recurrent gliomas from the Glioma Longitudinal Analysis Consortium and 3,693 post-treatment metastatic tumors from the Hartwig Medical Foundation. We identified radiotherapy-associated significant increases in the burden of small deletions (5-15 bp) and large deletions (20+ bp to chromosome-arm length). Read More

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Inhibition of DNA-PK with AZD7648 Sensitizes Tumor Cells to Radiotherapy and Induces Type I IFN-Dependent Durable Tumor Control.

Clin Cancer Res 2021 May 19. Epub 2021 May 19.

Bioscience, Early Oncology, Oncology R&D, AstraZeneca, Cambridge, United Kingdom.

Purpose: Combining radiotherapy (RT) with DNA damage response inhibitors may lead to increased tumor cell death through radiosensitization. DNA-dependent protein kinase (DNA-PK) plays an important role in DNA double-strand break repair via the nonhomologous end joining (NHEJ) pathway. We hypothesized that in addition to a radiosensitizing effect from the combination of RT with AZD7648, a potent and specific inhibitor of DNA-PK, combination therapy may also lead to modulation of an anticancer immune response. Read More

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Effect of ARTEMIS (DCLRE1C) deficiency and microinjection timing on editing efficiency during somatic cell nuclear transfer and in vitro fertilization using the CRISPR/Cas9 system.

Theriogenology 2021 Aug 3;170:107-116. Epub 2021 May 3.

Department of Animal Science, Iowa State University, Ames, IA, United States. Electronic address:

The ability to efficiently introduce site-specific genetic modifications to the mammalian genome has been dramatically improved with the use of the CRISPR/Cas9 system. CRISPR/Cas9 is a powerful tool used to generate genetic modifications by causing double-strand breaks (DSBs) in DNA. Artemis (ART; also known as DCLRE1C), is a nuclear protein and is essential for DSB end joining in DNA repair via the canonical non-homologous end joining (c-NHEJ) pathway. Read More

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Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging.

J Vis Exp 2021 04 28(170). Epub 2021 Apr 28.

Oncology Division, Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion; Department of Molecular Biology, Medical Biochemistry, and Pathology, Laval University Cancer Research Center;

The study of the DNA damage response (DDR) is a complex and essential field, which has only become more important due to the use of DDR-targeting drugs for cancer treatment. These targets are poly(ADP-ribose) polymerases (PARPs), which initiate various forms of DNA repair. Inhibiting these enzymes using PARP inhibitors (PARPi) achieves synthetic lethality by conferring a therapeutic vulnerability in homologous recombination (HR)-deficient cells due to mutations in breast cancer type 1 (BRCA1), BRCA2, or partner and localizer of BRCA2 (PALB2). Read More

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Ubiquitylation in DNA double-strand break repair.

DNA Repair (Amst) 2021 Jul 7;103:103129. Epub 2021 May 7.

Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. Electronic address:

Genome integrity is constantly challenged by various DNA lesions with DNA double-strand breaks (DSBs) as the most cytotoxic lesions. In order to faithfully repair DSBs, DNA damage response (DDR) signaling networks have evolved, which organize many multi-protein complexes to deal with the encountered DNA damage. Spatiotemporal dynamics of these protein complexes at DSBs are mainly modulated by post-translational modifications (PTMs). Read More

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Downregulation of both mismatch repair and non-homologous end-joining pathways in hypoxic brain tumour cell lines.

PeerJ 2021 30;9:e11275. Epub 2021 Apr 30.

Institute of Systems, Molecular and Integrative Biology, Department of Molecular Physiology and Cell Signalling, University of Liverpool, Liverpool, Merseyside, United Kingdom.

Glioblastoma, a grade IV astrocytoma, has a poor survival rate in part due to ineffective treatment options available. These tumours are heterogeneous with areas of low oxygen levels, termed hypoxic regions. Many intra-cellular signalling pathways, including DNA repair, can be altered by hypoxia. Read More

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CRISPAltRations: a validated cloud-based approach for interrogation of double-strand break repair mediated by CRISPR genome editing.

Mol Ther Methods Clin Dev 2021 Jun 2;21:478-491. Epub 2021 Apr 2.

Integrated DNA Technologies, Coralville, IA 52241, USA.

CRISPR systems enable targeted genome editing in a wide variety of organisms by introducing single- or double-strand DNA breaks, which are repaired using endogenous molecular pathways. Characterization of on- and off-target editing events from CRISPR proteins can be evaluated using targeted genome resequencing. We characterized DNA repair fingerprints that result from non-homologous end joining (NHEJ) after double-stranded breaks (DSBs) were introduced by Cas9 or Cas12a for >500 paired treatment/control experiments. Read More

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CopyCatchers are versatile active genetic elements that detect and quantify inter-homolog somatic gene conversion.

Nat Commun 2021 05 11;12(1):2625. Epub 2021 May 11.

Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.

CRISPR-based active genetic elements, or gene-drives, copied via homology-directed repair (HDR) in the germline, are transmitted to progeny at super-Mendelian frequencies. Active genetic elements also can generate widespread somatic mutations, but the genetic basis for such phenotypes remains uncertain. It is generally assumed that such somatic mutations are generated by non-homologous end-joining (NHEJ), the predominant double stranded break repair pathway active in somatic cells. Read More

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Recruitment of MRE-11 to complex DNA damage is modulated by meiosis-specific chromosome organization.

Mutat Res 2021 Jan-Jun;822:111743. Epub 2021 Apr 20.

Department of Biology, University of Iowa, Iowa City, IA, 52241, USA. Electronic address:

DNA double-strand breaks (DSBs) are one of the most dangerous assaults on the genome, and yet their natural and programmed production are inherent to life. When DSBs arise close together they are particularly deleterious, and their repair may require an altered form of the DNA damage response. Our understanding of how clustered DSBs are repaired in the germline is unknown. Read More

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[CRISPR/Cas9 technology in disease research and therapy: a review].

Sheng Wu Gong Cheng Xue Bao 2021 Apr;37(4):1205-1228

College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.

Genome editing is a genetic manipulation technique that can modify DNA sequences at the genome level, including insertion, knockout, replacement and point mutation of specific DNA fragments. The ultimate principle of genome editing technology relying on engineered nucleases is to generate double-stranded DNA breaks at specific locations in genome and then repair them through non-homologous end joining or homologous recombination. With the intensive study of these nucleases, genome editing technology develops rapidly. Read More

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Use of single guided Cas9 nickase to facilitate precise and efficient genome editing in human iPSCs.

Sci Rep 2021 May 10;11(1):9865. Epub 2021 May 10.

Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University School of Medicine, CMSC 8-121, 600 N. Wolfe St, Baltimore, MD, 21287, USA.

Cas9 nucleases permit rapid and efficient generation of gene-edited cell lines. However, in typical protocols, mutations are intentionally introduced into the donor template to avoid the cleavage of donor template or re-cleavage of the successfully edited allele, compromising the fidelity of the isogenic lines generated. In addition, the double-stranded breaks (DSBs) used for editing can introduce undesirable "on-target" indels within the second allele of successfully modified cells via non-homologous end joining (NHEJ). Read More

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Marker-free quantification of repair pathway utilization at Cas9-induced double-strand breaks.

Nucleic Acids Res 2021 05;49(9):5095-5105

Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.

Genome integrity and genome engineering require efficient repair of DNA double-strand breaks (DSBs) by non-homologous end joining (NHEJ), homologous recombination (HR), or alternative end-joining pathways. Here we describe two complementary methods for marker-free quantification of DSB repair pathway utilization at Cas9-targeted chromosomal DSBs in mammalian cells. The first assay features the analysis of amplicon next-generation sequencing data using ScarMapper, an iterative break-associated alignment algorithm to classify individual repair products based on deletion size, microhomology usage, and insertions. Read More

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CRISPR-Cas-mediated chromosome engineering for crop improvement and synthetic biology.

Nat Plants 2021 May 6;7(5):566-573. Epub 2021 May 6.

Botanical Institute, Karlsruhe Institute of Technology, Karlsruhe, Germany.

Plant breeding relies on the presence of genetic variation, as well as on the ability to break or stabilize genetic linkages between traits. The development of the genome-editing tool clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) has allowed breeders to induce genetic variability in a controlled and site-specific manner, and to improve traits with high efficiency. However, the presence of genetic linkages is a major obstacle to the transfer of desirable traits from wild species to their cultivated relatives. Read More

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Creation of a new class of radiosensitizers for glioblastoma based on the mibefradil pharmacophore.

Oncotarget 2021 Apr 27;12(9):891-906. Epub 2021 Apr 27.

Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06510-8034, USA.

Glioblastoma (GBM) is the most common primary malignant tumor of the central nervous system with a dismal prognosis. Locoregional failure is common despite high doses of radiation therapy, which has prompted great interest in developing novel strategies to radiosensitize these cancers. Our group previously identified a calcium channel blocker (CCB), mibefradil, as a potential GBM radiosensitizer. Read More

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RAG enhances BCR-ABL1-positive leukemic cell growth through its endonuclease activity in vitro and in vivo.

Cancer Sci 2021 May 4. Epub 2021 May 4.

Department of Pathogenic Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.

BCR-ABL1 gene fusion associated with additional DNA lesions involves the pathogenesis of chronic myelogenous leukemia (CML) from a chronic phase (CP) to a blast crisis of B lymphoid (CML-LBC) lineage and BCR-ABL1 acute lymphoblastic leukemia (BCR-ABL1 ALL). The recombination-activating gene RAG1 and RAG2 (collectively, RAG) proteins that assemble a diverse set of antigen receptor genes during lymphocyte development are abnormally expressed in CML-LBC and BCR-ABL1 ALL. However, the direct involvement of dysregulated RAG in disease progression remains unclear. Read More

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Homology-based repair induced by CRISPR-Cas nucleases in mammalian embryo genome editing.

Protein Cell 2021 May 4. Epub 2021 May 4.

MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.

Recent advances in genome editing, especially CRISPR-Cas nucleases, have revolutionized both laboratory research and clinical therapeutics. CRISPR-Cas nucleases, together with the DNA damage repair pathway in cells, enable both genetic diversification by classical non-homologous end joining (c-NHEJ) and precise genome modification by homology-based repair (HBR). Genome editing in zygotes is a convenient way to edit the germline, paving the way for animal disease model generation, as well as human embryo genome editing therapy for some life-threatening and incurable diseases. Read More

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DNA damage and repair in differentiation of stem cells and cells of connective cell lineages: A trigger or a complication?

Eur J Histochem 2021 May 3;65(2). Epub 2021 May 3.

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The review summarizes literature data on the role of DNA breaks and DNA repair in differentiation of pluripotent stem cells (PSC) and connective cell lineages. PSC, including embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC), are rapidly dividing cells with highly active DNA damage response (DDR) mechanisms to ensure the stability and integrity of the DNA. In PSCs, the most common DDR mechanism is error-free homologous recombination (HR) that is primarily active during S phase of the cell cycle, whereas in quiescent, slow-dividing or non-dividing tissue progenitors and terminally differentiated cells, error-prone non-homologous end joining (NHEJ) mechanism of the double-strand break (DSB) repair is dominating. Read More

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PARP1: Structural insights and pharmacological targets for inhibition.

DNA Repair (Amst) 2021 Jul 14;103:103125. Epub 2021 Apr 14.

Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA. Electronic address:

Poly(ADP-ribose) polymerase 1 (PARP1, also known as ADPRT1) is a multifunctional human ADP-ribosyltransferase. It plays a role in multiple DNA repair pathways, including the base excision repair (BER), non-homologous end joining (NHEJ), homologous recombination (HR), and Okazaki-fragment processing pathways. In response to DNA strand breaks, PARP1 covalently attaches ADP-ribose moieties to arginine, glutamate, aspartate, cysteine, lysine, and serine acceptor sites on both itself and other proteins. Read More

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Phf5a regulates DNA repair in class switch recombination via p400 and histone H2A variant deposition.

EMBO J 2021 Jun 3;40(12):e106393. Epub 2021 May 3.

Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.

Antibody class switch recombination (CSR) is a locus-specific genomic rearrangement mediated by switch (S) region transcription, activation-induced cytidine deaminase (AID)-induced DNA breaks, and their resolution by non-homologous end joining (NHEJ)-mediated DNA repair. Due to the complex nature of the recombination process, numerous cofactors are intimately involved, making it important to identify rate-limiting factors that impact on DNA breaking and/or repair. Using an siRNA-based loss-of-function screen of genes predicted to encode PHD zinc-finger-motif proteins, we identify the splicing factor Phf5a/Sf3b14b as a novel modulator of the DNA repair step of CSR. Read More

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Catalysis-dependent and redundant roles of Dma1 and Dma2 in maintenance of genome stability in Saccharomyces cerevisiae.

J Biol Chem 2021 Apr 29:100721. Epub 2021 Apr 29.

Department of Biochemistry & Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA. Electronic address:

DNA double strand breaks (DSBs) are among the deleterious lesions that are both endogenous and exogenous in origin, and are repaired by non-homologous end joining (NHEJ) or homologous recombination (HR). However, the molecular mechanisms responsible for maintaining genome stability remain incompletely understood. Here, we investigate the role of two E3 ligases, Dma1 and Dma2 (homologs of human RNF8) in the maintenance of genome stability in budding yeast. Read More

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