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Bellani MA, Shaik A, Majumdar I, Ling C, Seidman MM. Repair of genomic interstrand crosslinks. DNA Repair (Amst) 2024; 141:103739. [PMID: 39106540 DOI: 10.1016/j.dnarep.2024.103739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 07/11/2024] [Accepted: 07/25/2024] [Indexed: 08/09/2024]
Abstract
Genomic interstrand crosslinks (ICLs) are formed by reactive species generated during normal cellular metabolism, produced by the microbiome, and employed in cancer chemotherapy. While there are multiple options for replication dependent and independent ICL repair, the crucial step for each is unhooking one DNA strand from the other. Much of our insight into mechanisms of unhooking comes from powerful model systems based on plasmids with defined ICLs introduced into cells or cell free extracts. Here we describe the properties of exogenous and endogenous ICL forming compounds and provide an historical perspective on early work on ICL repair. We discuss the modes of unhooking elucidated in the model systems, the concordance or lack thereof in drug resistant tumors, and the evolving view of DNA adducts, including ICLs, formed by metabolic aldehydes.
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Affiliation(s)
- Marina A Bellani
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Althaf Shaik
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Ishani Majumdar
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Chen Ling
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Michael M Seidman
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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2
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Donnio LM, Giglia-Mari G. Keep calm and reboot - how cells restart transcription after DNA damage and DNA repair. FEBS Lett 2024. [PMID: 38991979 DOI: 10.1002/1873-3468.14964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/12/2024] [Accepted: 04/21/2024] [Indexed: 07/13/2024]
Abstract
The effects of genotoxic agents on DNA and the processes involved in their removal have been thoroughly studied; however, very little is known about the mechanisms governing the reinstatement of cellular activities after DNA repair, despite restoration of the damage-induced block of transcription being essential for cell survival. In addition to impeding transcription, DNA lesions have the potential to disrupt the precise positioning of chromatin domains within the nucleus and alter the meticulously organized architecture of the nucleolus. Alongside the necessity of resuming transcription mediated by RNA polymerase 1 and 2 transcription, it is crucial to restore the structure of the nucleolus to facilitate optimal ribosome biogenesis and ensure efficient and error-free translation. Here, we examine the current understanding of how transcriptional activity from RNA polymerase 2 is reinstated following DNA repair completion and explore the mechanisms involved in reassembling the nucleolus to safeguard the correct progression of cellular functions. Given the lack of information on this vital function, this Review seeks to inspire researchers to explore deeper into this specific subject and offers essential suggestions on how to investigate this complex and nearly unexplored process further.
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Affiliation(s)
- Lise-Marie Donnio
- Institut NeuroMyoGène-Pathophysiology and Genetics of Neuron and Muscle (INMG_PGNM), CNRS UMR 5261, INSERM U1315, Université Claude Bernard Lyon 1, Lyon, 69008, France
| | - Giuseppina Giglia-Mari
- Institut NeuroMyoGène-Pathophysiology and Genetics of Neuron and Muscle (INMG_PGNM), CNRS UMR 5261, INSERM U1315, Université Claude Bernard Lyon 1, Lyon, 69008, France
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3
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Alanazi N, Siyal A, Basit S, Shammas M, Al-Mukhaylid S, Aleem A, Mahmood A, Iqbal Z. Clinical Validation of the Somatic FANCD2 Mutation (c.2022-5C>T) as a Novel Molecular Biomarker for Early Disease Progression in Chronic Myeloid Leukemia: A Case-Control Study. Hematol Rep 2024; 16:465-478. [PMID: 39051418 PMCID: PMC11270283 DOI: 10.3390/hematolrep16030045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/03/2024] [Accepted: 06/26/2024] [Indexed: 07/27/2024] Open
Abstract
Background: Chronic myeloid leukemia (CML) results from chromosomal translocation t(9;22) leading to the formation of the BCR-ABL fusion oncogene. CML has three stages: the chronic phase (CP), the accelerated phase (AP), and the blast crisis (BC). Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of CML. TKIs work well in CP-CML, and these patients have a survival rate similar to the normal population, but TKIs are less effective in advanced-phase CML. Even with current advances in treatment, BC-CML patients have an average overall survival of less than a year. Early recognition of CML patients at risk of disease progression can help in timely interventions with appropriate TKIs or other therapeutic modalities. Although some markers of disease progression like BCR-ABL kinase domain, ASXL1, and GATA2 mutations are available, no universal and exclusively specific molecular biomarkers exist to early diagnose CML patients at risk of CML progression for timely therapeutic interventions to delay or minimize blast crisis transformation in CML. A recent study found that all BC-CML patients harbored the FANCD2 (c.2022-5C>T) mutation. Therefore, the current study was designed to detect this FANCD2 mutant in AP-CML (early progression phase) and to clinically validate its potential as a novel molecular biomarker of early CML progression from CP to AP. Methods: Our study comprised 123 CP-CML (control group) and 60 AP-CML patients (experimental group) from 2 oncology centers, from January 2020 to July 2023. Mean hemoglobin level, WBC count, platelet count, treatment type, hepatomegaly, splenomegaly, and survival status of AP-CML patients were significantly different from those of CP-CML patients. However, as these clinical parameters cannot help in the early detection of patients at risk of CML progression, there was a need for a clinically validated biomarker of AP-CML. DNA was extracted from the patients' blood samples, and the FANCD2 gene was sequenced using an Illumina NextSeq500 next-generation sequencer (NGS). Results: The NGS analysis revealed a unique splice-site mutation in the FANCD2 gene (c.2022-5C>T). This mutation was detected in the majority (98.3%) of AP-CML patients but in none of the CP-CML patients or healthy control sequences from genomic databases. The mutation was confirmed by Sanger sequencing. FANCD2 is a member of the Fanconi anemia pathway genes involved in DNA repair and genomic stability, and aberrations of this gene are associated with many cancers. Conclusions: In conclusion, our study shows that the somatic FANCD2 (c.2022-5C>T) mutation is a new molecular biomarker for early CML progression. We recommend further clinical validation of this biomarker in prospective clinical trials.
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Affiliation(s)
- Nawaf Alanazi
- Division of Hematology/Oncology, Department of Pediatrics, King Abdulaziz Hospital, College of Applied Medical Sciences (CoAMS), King Saud Bin Abdulaziz University for Health Sciences, Al-Ahsa 36428, Saudi Arabia;
| | - Abdulaziz Siyal
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh 11495, Saudi Arabia
| | - Sulman Basit
- Centre for Genetics and Inherited Diseases, Taiba University, Madinah 42353, Saudi Arabia;
| | - Masood Shammas
- Dana Farbar Cancer Institute, University of Harvard, Boston, MA 02138, USA;
| | - Sarah Al-Mukhaylid
- Clinical Laboratory Department, Johns Hopkins Aramco HealthCare (JHAH), Alahsa 36423, Saudi Arabia;
- Alumni, GEM, CLSP, CoAMS-A, KSAU-HS, Al-Ahsa 36428, Saudi Arabia
| | - Aamer Aleem
- Department of Medicine, Division of Hematology/Oncology, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh 11472, Saudi Arabia;
| | - Amer Mahmood
- Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh 11495, Saudi Arabia
- Department of Medicine, Division of Hematology/Oncology, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh 11472, Saudi Arabia;
| | - Zafar Iqbal
- Alumni, GEM, CLSP, CoAMS-A, KSAU-HS, Al-Ahsa 36428, Saudi Arabia
- Genomic & Experimental Medicine Group (GEM) Molecular Oncology/Hematology Group (MOH) & Quality Assurance and Accreditation Unit (QAAA), & Clinical Laboratory Sciences Program (CLSP), College of Applied Medical Sciences (CoAMS-A), King Abdullah International Medical Research Centre (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS), Saudi Society for Blood and Marrow Transplantation (SSBMT), King Abdulaziz Medical City, National Guard Health Affairs, Al-Ahsa 31982, Saudi Arabia
- Pakistan Society for Molecular and Clinical Hematology, Lahore 54000, Pakistan
- Hematology, Oncology & Pharmacogenetic Engineering Sciences Group (HOPES), Division of Next-Generation Medical Biotechnology (NeMB), Department of Biotechnology, Qarshi University, Lahore 54000, Pakistan
- Hematology, Oncology & Pharmacogenetic Engineering Sciences Group (HOPES), Centre for Applied Molecular Biology (CAMB), University of the Punjab, Lahore 54590, Pakistan
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4
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Kim KH, Hong EP, Lee Y, McLean ZL, Elezi E, Lee R, Kwak S, McAllister B, Massey TH, Lobanov S, Holmans P, Orth M, Ciosi M, Monckton DG, Long JD, Lucente D, Wheeler VC, MacDonald ME, Gusella JF, Lee JM. Posttranscriptional regulation of FAN1 by miR-124-3p at rs3512 underlies onset-delaying genetic modification in Huntington's disease. Proc Natl Acad Sci U S A 2024; 121:e2322924121. [PMID: 38607933 PMCID: PMC11032436 DOI: 10.1073/pnas.2322924121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/06/2024] [Indexed: 04/14/2024] Open
Abstract
Many Mendelian disorders, such as Huntington's disease (HD) and spinocerebellar ataxias, arise from expansions of CAG trinucleotide repeats. Despite the clear genetic causes, additional genetic factors may influence the rate of those monogenic disorders. Notably, genome-wide association studies discovered somewhat expected modifiers, particularly mismatch repair genes involved in the CAG repeat instability, impacting age at onset of HD. Strikingly, FAN1, previously unrelated to repeat instability, produced the strongest HD modification signals. Diverse FAN1 haplotypes independently modify HD, with rare genetic variants diminishing DNA binding or nuclease activity of the FAN1 protein, hastening HD onset. However, the mechanism behind the frequent and the most significant onset-delaying FAN1 haplotype lacking missense variations has remained elusive. Here, we illustrated that a microRNA acting on 3'-UTR (untranslated region) SNP rs3512, rather than transcriptional regulation, is responsible for the significant FAN1 expression quantitative trait loci signal and allelic imbalance in FAN1 messenger ribonucleic acid (mRNA), accounting for the most significant and frequent onset-delaying modifier haplotype in HD. Specifically, miR-124-3p selectively targets the reference allele at rs3512, diminishing the stability of FAN1 mRNA harboring that allele and consequently reducing its levels. Subsequent validation analyses, including the use of antagomir and 3'-UTR reporter vectors with swapped alleles, confirmed the specificity of miR-124-3p at rs3512. Together, these findings indicate that the alternative allele at rs3512 renders the FAN1 mRNA less susceptible to miR-124-3p-mediated posttranscriptional regulation, resulting in increased FAN1 levels and a subsequent delay in HD onset by mitigating CAG repeat instability.
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Affiliation(s)
- Kyung-Hee Kim
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
| | - Eun Pyo Hong
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
| | - Yukyeong Lee
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
| | - Zachariah L. McLean
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
- Medical and Population Genetics Program, The Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA02142
| | - Emanuela Elezi
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
| | | | | | - Branduff McAllister
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CardiffCF24 4HQ, United Kingdom
| | - Thomas H. Massey
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CardiffCF24 4HQ, United Kingdom
| | - Sergey Lobanov
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CardiffCF24 4HQ, United Kingdom
| | - Peter Holmans
- Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, CardiffCF24 4HQ, United Kingdom
| | - Michael Orth
- University Hospital of Old Age Psychiatry and Psychotherapy, Bern University, CH-3000Bern 60, Switzerland
| | - Marc Ciosi
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Darren G. Monckton
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Jeffrey D. Long
- Department of Psychiatry, Carver College of Medicine, University of Iowa, Iowa City, IA52242
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA52242
| | - Diane Lucente
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
| | - Vanessa C. Wheeler
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
| | - Marcy E. MacDonald
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
- Medical and Population Genetics Program, The Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA02142
| | - James F. Gusella
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Medical and Population Genetics Program, The Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA02142
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA02115
| | - Jong-Min Lee
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA02114
- Department of Neurology, Harvard Medical School, Boston, MA02115
- Medical and Population Genetics Program, The Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA02142
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5
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Phadte AS, Bhatia M, Ebert H, Abdullah H, Elrazaq EA, Komolov KE, Pluciennik A. FAN1 removes triplet repeat extrusions via a PCNA- and RFC-dependent mechanism. Proc Natl Acad Sci U S A 2023; 120:e2302103120. [PMID: 37549289 PMCID: PMC10438374 DOI: 10.1073/pnas.2302103120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/22/2023] [Indexed: 08/09/2023] Open
Abstract
Human genome-wide association studies have identified FAN1 and several DNA mismatch repair (MMR) genes as modifiers of Huntington's disease age of onset. In animal models, FAN1 prevents somatic expansion of CAG triplet repeats, whereas MMR proteins promote this process. To understand the molecular basis of these opposing effects, we evaluated FAN1 nuclease function on DNA extrahelical extrusions that represent key intermediates in triplet repeat expansion. Here, we describe a strand-directed, extrusion-provoked nuclease function of FAN1 that is activated by RFC, PCNA, and ATP at physiological ionic strength. Activation of FAN1 in this manner results in DNA cleavage in the vicinity of triplet repeat extrahelical extrusions thereby leading to their removal in human cell extracts. The role of PCNA and RFC is to confer strand directionality to the FAN1 nuclease, and this reaction requires a physical interaction between PCNA and FAN1. Using cell extracts, we show that FAN1-dependent CAG extrusion removal relies on a very short patch excision-repair mechanism that competes with MutSβ-dependent MMR which is characterized by longer excision tracts. These results provide a mechanistic basis for the role of FAN1 in preventing repeat expansion and could explain the antagonistic effects of MMR and FAN1 in disease onset/progression.
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Affiliation(s)
- Ashutosh S. Phadte
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
| | - Mayuri Bhatia
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
| | - Hope Ebert
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
| | - Haaris Abdullah
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
| | - Essam Abed Elrazaq
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
| | - Konstantin E. Komolov
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
| | - Anna Pluciennik
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA19107
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6
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Awwad SW, Serrano-Benitez A, Thomas JC, Gupta V, Jackson SP. Revolutionizing DNA repair research and cancer therapy with CRISPR-Cas screens. Nat Rev Mol Cell Biol 2023; 24:477-494. [PMID: 36781955 DOI: 10.1038/s41580-022-00571-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2022] [Indexed: 02/15/2023]
Abstract
All organisms possess molecular mechanisms that govern DNA repair and associated DNA damage response (DDR) processes. Owing to their relevance to human disease, most notably cancer, these mechanisms have been studied extensively, yet new DNA repair and/or DDR factors and functional interactions between them are still being uncovered. The emergence of CRISPR technologies and CRISPR-based genetic screens has enabled genome-scale analyses of gene-gene and gene-drug interactions, thereby providing new insights into cellular processes in distinct DDR-deficiency genetic backgrounds and conditions. In this Review, we discuss the mechanistic basis of CRISPR-Cas genetic screening approaches and describe how they have contributed to our understanding of DNA repair and DDR pathways. We discuss how DNA repair pathways are regulated, and identify and characterize crosstalk between them. We also highlight the impacts of CRISPR-based studies in identifying novel strategies for cancer therapy, and in understanding, overcoming and even exploiting cancer-drug resistance, for example in the contexts of PARP inhibition, homologous recombination deficiencies and/or replication stress. Lastly, we present the DDR CRISPR screen (DDRcs) portal , in which we have collected and reanalysed data from CRISPR screen studies and provide a tool for systematically exploring them.
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Affiliation(s)
- Samah W Awwad
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Almudena Serrano-Benitez
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK.
| | - John C Thomas
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK.
| | - Vipul Gupta
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Stephen P Jackson
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Cambridge, UK.
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7
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Airik M, Arbore H, Childs E, Huynh AB, Phua YL, Chen CW, Aird K, Bharathi S, Zhang B, Conlon P, Kmoch S, Kidd K, Bleyer AJ, Vockley J, Goetzman E, Wipf P, Airik R. Mitochondrial ROS Triggers KIN Pathogenesis in FAN1-Deficient Kidneys. Antioxidants (Basel) 2023; 12:900. [PMID: 37107275 PMCID: PMC10135478 DOI: 10.3390/antiox12040900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/02/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023] Open
Abstract
Karyomegalic interstitial nephritis (KIN) is a genetic adult-onset chronic kidney disease (CKD) characterized by genomic instability and mitotic abnormalities in the tubular epithelial cells. KIN is caused by recessive mutations in the FAN1 DNA repair enzyme. However, the endogenous source of DNA damage in FAN1/KIN kidneys has not been identified. Here we show, using FAN1-deficient human renal tubular epithelial cells (hRTECs) and FAN1-null mice as a model of KIN, that FAN1 kidney pathophysiology is triggered by hypersensitivity to endogenous reactive oxygen species (ROS), which cause chronic oxidative and double-strand DNA damage in the kidney tubular epithelial cells, accompanied by an intrinsic failure to repair DNA damage. Furthermore, persistent oxidative stress in FAN1-deficient RTECs and FAN1 kidneys caused mitochondrial deficiencies in oxidative phosphorylation and fatty acid oxidation. The administration of subclinical, low-dose cisplatin increased oxidative stress and aggravated mitochondrial dysfunction in FAN1-deficient kidneys, thereby exacerbating KIN pathophysiology. In contrast, treatment of FAN1 mice with a mitochondria-targeted ROS scavenger, JP4-039, attenuated oxidative stress and accumulation of DNA damage, mitigated tubular injury, and preserved kidney function in cisplatin-treated FAN1-null mice, demonstrating that endogenous oxygen stress is an important source of DNA damage in FAN1-deficient kidneys and a driver of KIN pathogenesis. Our findings indicate that therapeutic modulation of kidney oxidative stress may be a promising avenue to mitigate FAN1/KIN kidney pathophysiology and disease progression in patients.
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Affiliation(s)
- Merlin Airik
- Division of Nephrology, Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Haley Arbore
- Division of Nephrology, Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Elizabeth Childs
- Division of Nephrology, Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Amy B. Huynh
- Division of Nephrology, Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Yu Leng Phua
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Chi Wei Chen
- Department of Pharmacology & Chemical Biology and UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Katherine Aird
- Department of Pharmacology & Chemical Biology and UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sivakama Bharathi
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine and UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Bob Zhang
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine and UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Peter Conlon
- Nephrology Department, Beaumont Hospital, D09 V2N0 Dublin, Ireland
| | - Stanislav Kmoch
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University, 128 08 Prague, Czech Republic
| | - Kendrah Kidd
- Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | | | - Jerry Vockley
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine and UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Eric Goetzman
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine and UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Rannar Airik
- Division of Nephrology, Department of Pediatrics, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15224, USA
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8
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Garaycoechea JI, Quinlan C, Luijsterburg MS. Pathological consequences of DNA damage in the kidney. Nat Rev Nephrol 2023; 19:229-243. [PMID: 36702905 DOI: 10.1038/s41581-022-00671-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2022] [Indexed: 01/27/2023]
Abstract
DNA lesions that evade repair can lead to mutations that drive the development of cancer, and cellular responses to DNA damage can trigger senescence and cell death, which are associated with ageing. In the kidney, DNA damage has been implicated in both acute and chronic kidney injury, and in renal cell carcinoma. The susceptibility of the kidney to chemotherapeutic agents that damage DNA is well established, but an unexpected link between kidney ciliopathies and the DNA damage response has also been reported. In addition, human genetic deficiencies in DNA repair have highlighted DNA crosslinks, DNA breaks and transcription-blocking damage as lesions that are particularly toxic to the kidney. Genetic tools in mice, as well as advances in kidney organoid and single-cell RNA sequencing technologies, have provided important insights into how specific kidney cell types respond to DNA damage. The emerging view is that in the kidney, DNA damage affects the local microenvironment by triggering a damage response and cell proliferation to replenish injured cells, as well as inducing systemic responses aimed at reducing exposure to genotoxic stress. The pathological consequences of DNA damage are therefore key to the nephrotoxicity of DNA-damaging agents and the kidney phenotypes observed in human DNA repair-deficiency disorders.
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Affiliation(s)
- Juan I Garaycoechea
- Hubrecht Institute-KNAW, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Catherine Quinlan
- Department of Paediatrics, University of Melbourne, Parkville, Australia
- Department of Nephrology, Royal Children's Hospital, Melbourne, Australia
- Department of Kidney Regeneration, Murdoch Children's Research Institute, Melbourne, Australia
| | - Martijn S Luijsterburg
- Department of Human Genetics, Leiden University Medical Center (LUMC), Leiden, The Netherlands.
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9
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Hespanhol JT, Karman L, Sanchez-Limache DE, Bayer-Santos E. Intercepting biological messages: Antibacterial molecules targeting nucleic acids during interbacterial conflicts. Genet Mol Biol 2023; 46:e20220266. [PMID: 36880694 PMCID: PMC9990079 DOI: 10.1590/1678-4685-gmb-2022-0266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/25/2022] [Indexed: 03/08/2023] Open
Abstract
Bacteria live in polymicrobial communities and constantly compete for resources. These organisms have evolved an array of antibacterial weapons to inhibit the growth or kill competitors. The arsenal comprises antibiotics, bacteriocins, and contact-dependent effectors that are either secreted in the medium or directly translocated into target cells. During bacterial antagonistic encounters, several cellular components important for life become a weak spot prone to an attack. Nucleic acids and the machinery responsible for their synthesis are well conserved across the tree of life. These molecules are part of the information flow in the central dogma of molecular biology and mediate long- and short-term storage for genetic information. The aim of this review is to summarize the diversity of antibacterial molecules that target nucleic acids during antagonistic interbacterial encounters and discuss their potential to promote the emergence antibiotic resistance.
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Affiliation(s)
- Julia Takuno Hespanhol
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Lior Karman
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | | | - Ethel Bayer-Santos
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
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10
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Huang YJ, Chen JY, Yan M, Davis AG, Miyauchi S, Chen L, Hao Y, Katz S, Bejar R, Abdel-Wahab O, Fu XD, Zhang DE. RUNX1 deficiency cooperates with SRSF2 mutation to induce multilineage hematopoietic defects characteristic of MDS. Blood Adv 2022; 6:6078-6092. [PMID: 36206200 PMCID: PMC9772487 DOI: 10.1182/bloodadvances.2022007804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/15/2022] [Accepted: 09/13/2022] [Indexed: 12/15/2022] Open
Abstract
Myelodysplastic syndromes (MDSs) are a heterogeneous group of hematologic malignancies with a propensity to progress to acute myeloid leukemia. Causal mutations in multiple classes of genes have been identified in patients with MDS with some patients harboring more than 1 mutation. Interestingly, double mutations tend to occur in different classes rather than the same class of genes, as exemplified by frequent cooccurring mutations in the transcription factor RUNX1 and the splicing factor SRSF2. This prototypic double mutant provides an opportunity to understand how their divergent functions in transcription and posttranscriptional regulation may be altered to jointly promote MDS. Here, we report a mouse model in which Runx1 knockout was combined with the Srsf2 P95H mutation to cause multilineage hematopoietic defects. Besides their additive and synergistic effects, we also unexpectedly noted a degree of antagonizing activity of single mutations in specific hematopoietic progenitors. To uncover the mechanism, we further developed a cellular model using human K562 cells and performed parallel gene expression and splicing analyses in both human and murine contexts. Strikingly, although RUNX1 deficiency was responsible for altered transcription in both single and double mutants, it also induced dramatic changes in global splicing, as seen with mutant SRSF2, and only their combination induced missplicing of genes selectively enriched in the DNA damage response and cell cycle checkpoint pathways. Collectively, these data reveal the convergent impact of a prototypic MDS-associated double mutant on RNA processing and suggest that aberrant DNA damage repair and cell cycle regulation critically contribute to MDS development.
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Affiliation(s)
- Yi-Jou Huang
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
- Department of Molecular Biology, UCSD, La Jolla, CA
| | - Jia-Yu Chen
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA
| | - Ming Yan
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
| | - Amanda G. Davis
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
- Department of Molecular Biology, UCSD, La Jolla, CA
| | | | - Liang Chen
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA
| | - Yajing Hao
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA
| | - Sigrid Katz
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
| | - Rafael Bejar
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Xiang-Dong Fu
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
- Department of Cellular and Molecular Medicine, UC San Diego, La Jolla, CA
| | - Dong-Er Zhang
- Moores Cancer Center, UC San Diego (UCSD), La Jolla, CA
- Department of Molecular Biology, UCSD, La Jolla, CA
- Department of Pathology, UC San Diego, La Jolla, CA
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11
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Airik M, Phua YL, Huynh AB, McCourt BT, Rush BM, Tan RJ, Vockley J, Murray SL, Dorman A, Conlon PJ, Airik R. Persistent DNA damage underlies tubular cell polyploidization and progression to chronic kidney disease in kidneys deficient in the DNA repair protein FAN1. Kidney Int 2022; 102:1042-1056. [PMID: 35931300 PMCID: PMC9588672 DOI: 10.1016/j.kint.2022.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 06/24/2022] [Accepted: 07/06/2022] [Indexed: 12/14/2022]
Abstract
Defective DNA repair pathways contribute to the development of chronic kidney disease (CKD) in humans. However, the molecular mechanisms underlying DNA damage-induced CKD pathogenesis are not well understood. Here, we investigated the role of tubular cell DNA damage in the pathogenesis of CKD using mice in which the DNA repair protein Fan1 was knocked out. The phenotype of these mice is orthologous to the human DNA damage syndrome, karyomegalic interstitial nephritis (KIN). Inactivation of Fan1 in kidney proximal tubule cells sensitized the kidneys to genotoxic and obstructive injury characterized by replication stress and persistent DNA damage response activity. Accumulation of DNA damage in Fan1 tubular cells induced epithelial dedifferentiation and tubular injury. Characteristic to KIN, cells with chronic DNA damage failed to complete mitosis and underwent polyploidization. In vitro and in vivo studies showed that polyploidization was caused by the overexpression of DNA replication factors CDT1 and CDC6 in FAN1 deficient cells. Mechanistically, inhibiting DNA replication with Roscovitine reduced tubular injury, blocked the development of KIN and mitigated kidney function in these Fan1 knockout mice. Thus, our data delineate a mechanistic pathway by which persistent DNA damage in the kidney tubular cells leads to kidney injury and development of CKD. Furthermore, therapeutic modulation of cell cycle activity may provide an opportunity to mitigate the DNA damage response induced CKD progression.
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Affiliation(s)
- Merlin Airik
- Division of Nephrology, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yu Leng Phua
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Amy B Huynh
- Division of Nephrology, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Blake T McCourt
- Division of Nephrology, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brittney M Rush
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Roderick J Tan
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jerry Vockley
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Susan L Murray
- Department of Nephrology, Beaumont Hospital and Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Anthony Dorman
- Department of Nephrology, Beaumont Hospital and Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Peter J Conlon
- Department of Nephrology, Beaumont Hospital and Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Rannar Airik
- Division of Nephrology, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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12
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Hespanhol JT, Sanchez-Limache DE, Nicastro GG, Mead L, Llontop EE, Chagas-Santos G, Farah CS, de Souza RF, Galhardo RDS, Lovering AL, Bayer-Santos E. Antibacterial T6SS effectors with a VRR-Nuc domain are structure-specific nucleases. eLife 2022; 11:e82437. [PMID: 36226828 PMCID: PMC9635880 DOI: 10.7554/elife.82437] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/09/2022] [Indexed: 11/21/2022] Open
Abstract
The type VI secretion system (T6SS) secretes antibacterial effectors into target competitors. Salmonella spp. encode five phylogenetically distinct T6SSs. Here, we characterize the function of the SPI-22 T6SS of Salmonella bongori showing that it has antibacterial activity and identify a group of antibacterial T6SS effectors (TseV1-4) containing an N-terminal PAAR-like domain and a C-terminal VRR-Nuc domain encoded next to cognate immunity proteins with a DUF3396 domain (TsiV1-4). TseV2 and TseV3 are toxic when expressed in Escherichia coli and bacterial competition assays confirm that TseV2 and TseV3 are secreted by the SPI-22 T6SS. Phylogenetic analysis reveals that TseV1-4 are evolutionarily related to enzymes involved in DNA repair. TseV3 recognizes specific DNA structures and preferentially cleave splayed arms, generating DNA double-strand breaks and inducing the SOS response in target cells. The crystal structure of the TseV3:TsiV3 complex reveals that the immunity protein likely blocks the effector interaction with the DNA substrate. These results expand our knowledge on the function of Salmonella pathogenicity islands, the evolution of toxins used in biological conflicts, and the endogenous mechanisms regulating the activity of these toxins.
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Affiliation(s)
- Julia Takuno Hespanhol
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São PauloSão PauloBrazil
| | | | | | - Liam Mead
- Department of Biosciences, University of BirminghamBirminghamUnited Kingdom
| | - Edgar Enrique Llontop
- Departamento de Bioquímica, Instituto de Química, Universidade de São PauloSão PauloBrazil
| | - Gustavo Chagas-Santos
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São PauloSão PauloBrazil
| | - Chuck Shaker Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São PauloSão PauloBrazil
| | - Robson Francisco de Souza
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São PauloSão PauloBrazil
| | - Rodrigo da Silva Galhardo
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São PauloSão PauloBrazil
| | - Andrew L Lovering
- Department of Biosciences, University of BirminghamBirminghamUnited Kingdom
| | - Ethel Bayer-Santos
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São PauloSão PauloBrazil
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13
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Masnovo C, Lobo AF, Mirkin SM. Replication dependent and independent mechanisms of GAA repeat instability. DNA Repair (Amst) 2022; 118:103385. [PMID: 35952488 PMCID: PMC9675320 DOI: 10.1016/j.dnarep.2022.103385] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 11/20/2022]
Abstract
Trinucleotide repeat instability is a driver of human disease. Large expansions of (GAA)n repeats in the first intron of the FXN gene are the cause Friedreich's ataxia (FRDA), a progressive degenerative disorder which cannot yet be prevented or treated. (GAA)n repeat instability arises during both replication-dependent processes, such as cell division and intergenerational transmission, as well as in terminally differentiated somatic tissues. Here, we provide a brief historical overview on the discovery of (GAA)n repeat expansions and their association to FRDA, followed by recent advances in the identification of triplex H-DNA formation and replication fork stalling. The main body of this review focuses on the last decade of progress in understanding the mechanism of (GAA)n repeat instability during DNA replication and/or DNA repair. We propose that the discovery of additional mechanisms of (GAA)n repeat instability can be achieved via both comparative approaches to other repeat expansion diseases and genome-wide association studies. Finally, we discuss the advances towards FRDA prevention or amelioration that specifically target (GAA)n repeat expansions.
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Affiliation(s)
- Chiara Masnovo
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Ayesha F Lobo
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02155, USA.
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14
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Fu S, Phan AT, Mao D, Wang X, Gao G, Goff SP, Zhu Y. HIV-1 exploits the Fanconi anemia pathway for viral DNA integration. Cell Rep 2022; 39:110840. [PMID: 35613597 PMCID: PMC9250337 DOI: 10.1016/j.celrep.2022.110840] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/08/2022] [Accepted: 04/27/2022] [Indexed: 11/24/2022] Open
Abstract
The integration of HIV-1 DNA into the host genome results in single-strand gaps and 2-nt overhangs at the ends of viral DNA, which must be repaired by cellular enzymes. The cellular factors responsible for the DNA damage repair in HIV-1 DNA integration have not yet been well defined. We report here that HIV-1 infection potently activates the Fanconi anemia (FA) DNA repair pathway, and the FA effector proteins FANCI-D2 bind to the C-terminal domain of HIV-1 integrase. Knockout of FANCI blocks productive viral DNA integration and inhibits the replication of HIV-1. Finally, we show that the knockout of DNA polymerases or flap nuclease downstream of FANCI-D2 reduces the levels of integrated HIV-1 DNA, suggesting these enzymes may be responsible for the repair of DNA damages induced by viral DNA integration. These experiments reveal that HIV-1 exploits the FA pathway for the stable integration of viral DNA into host genome.
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Affiliation(s)
- Shaozu Fu
- CAS Key Laboratory of Infection and Immunity, CAS Centre for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - An Thanh Phan
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Dexin Mao
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Xinlu Wang
- CAS Key Laboratory of Infection and Immunity, CAS Centre for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangxia Gao
- CAS Key Laboratory of Infection and Immunity, CAS Centre for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Stephen P Goff
- Department of Biochemistry and Molecular Biophysics and of Microbiology and Immunology, Columbia University, New York, NY 10032, USA.
| | - Yiping Zhu
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA.
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15
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Clay DE, Jezuit EA, Montague RA, Fox DT. Conserved function of Drosophila Fancd2 monoubiquitination in response to double-strand DNA breaks. G3 (BETHESDA, MD.) 2022; 12:6589893. [PMID: 35595243 PMCID: PMC9339327 DOI: 10.1093/g3journal/jkac129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/12/2022] [Indexed: 11/12/2022]
Abstract
Fanconi anemia genes play key roles in metazoan DNA damage responses, and human FA mutations cause numerous disease phenotypes. In human cells, activating monoubiquitination of the Fanconi anemia protein Fancd2 occurs following diverse DNA damage stimuli. Monoubiquitinated Fancd2 forms nuclear foci to recruit additional repair factors. Fancd2 animal models to date have focused on molecular nulls or whole gene knockdown, leaving the specific in vivo role of monoubiquitination unclear. Using a point mutant in a conserved residue, we recently linked Drosophila Fancd2 monoubiquitination to a mitosis-specific DNA double-strand break response. In this context, we used CRISPR/Cas9 to generate the first animal model of an endogenous mutation in the conserved monoubiquitination site (fancd2K595R). Here, we expand upon our characterization of fancd2K595R. We also introduce and characterize additional Drosophila tools to study fancd2, including new mutant alleles and GFP-tagged rescue transgenes. Using these new reagents, we show the impact of Drosophila Fancd2 on organismal and cell viability, as well as on repair protein localization, in the presence or absence of double-strand breaks. These findings expand our understanding of Fanconi anemia gene function in vivo and provide useful reagents for DNA repair research.
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Affiliation(s)
- Delisa E Clay
- Department of Pharmacology and Cancer Biology, C318 Levine Science Research Center, Duke University Medical School, Durham, NC 27710, USA
| | - Erin A Jezuit
- Department of Pharmacology and Cancer Biology, C318 Levine Science Research Center, Duke University Medical School, Durham, NC 27710, USA
| | - Ruth A Montague
- Department of Pharmacology and Cancer Biology, C318 Levine Science Research Center, Duke University Medical School, Durham, NC 27710, USA
| | - Donald T Fox
- Corresponding author: Department of Pharmacology and Cancer Biology, C318 Levine Science Research Center, DUMC Box 3813, Duke University Medical School, Durham, NC 27710, USA.
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16
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The nuclease activity of DNA2 promotes exonuclease 1-independent mismatch repair. J Biol Chem 2022; 298:101831. [PMID: 35300981 PMCID: PMC9036127 DOI: 10.1016/j.jbc.2022.101831] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 12/03/2022] Open
Abstract
The DNA mismatch repair (MMR) system is a major DNA repair system that corrects DNA replication errors. In eukaryotes, the MMR system functions via mechanisms both dependent on and independent of exonuclease 1 (EXO1), an enzyme that has multiple roles in DNA metabolism. Although the mechanism of EXO1-dependent MMR is well understood, less is known about EXO1-independent MMR. Here, we provide genetic and biochemical evidence that the DNA2 nuclease/helicase has a role in EXO1-independent MMR. Biochemical reactions reconstituted with purified human proteins demonstrated that the nuclease activity of DNA2 promotes an EXO1-independent MMR reaction via a mismatch excision-independent mechanism that involves DNA polymerase δ. We show that DNA polymerase ε is not able to replace DNA polymerase δ in the DNA2-promoted MMR reaction. Unlike its nuclease activity, the helicase activity of DNA2 is dispensable for the ability of the protein to enhance the MMR reaction. Further examination established that DNA2 acts in the EXO1-independent MMR reaction by increasing the strand-displacement activity of DNA polymerase δ. These data reveal a mechanism for EXO1-independent mismatch repair.
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17
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Exome sequencing of individuals with Huntington's disease implicates FAN1 nuclease activity in slowing CAG expansion and disease onset. Nat Neurosci 2022; 25:446-457. [PMID: 35379994 PMCID: PMC8986535 DOI: 10.1038/s41593-022-01033-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 02/11/2022] [Indexed: 12/13/2022]
Abstract
The age at onset of motor symptoms in Huntington's disease (HD) is driven by HTT CAG repeat length but modified by other genes. In this study, we used exome sequencing of 683 patients with HD with extremes of onset or phenotype relative to CAG length to identify rare variants associated with clinical effect. We discovered damaging coding variants in candidate modifier genes identified in previous genome-wide association studies associated with altered HD onset or severity. Variants in FAN1 clustered in its DNA-binding and nuclease domains and were associated predominantly with earlier-onset HD. Nuclease activities of purified variants in vitro correlated with residual age at motor onset of HD. Mutating endogenous FAN1 to a nuclease-inactive form in an induced pluripotent stem cell model of HD led to rates of CAG expansion similar to those observed with complete FAN1 knockout. Together, these data implicate FAN1 nuclease activity in slowing somatic repeat expansion and hence onset of HD.
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18
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Deshmukh AL, Caron MC, Mohiuddin M, Lanni S, Panigrahi GB, Khan M, Engchuan W, Shum N, Faruqui A, Wang P, Yuen RKC, Nakamori M, Nakatani K, Masson JY, Pearson CE. FAN1 exo- not endo-nuclease pausing on disease-associated slipped-DNA repeats: A mechanism of repeat instability. Cell Rep 2021; 37:110078. [PMID: 34879276 DOI: 10.1016/j.celrep.2021.110078] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/02/2021] [Accepted: 11/09/2021] [Indexed: 12/19/2022] Open
Abstract
Ongoing inchworm-like CAG and CGG repeat expansions in brains, arising by aberrant processing of slipped DNAs, may drive Huntington's disease, fragile X syndrome, and autism. FAN1 nuclease modifies hyper-expansion rates by unknown means. We show that FAN1, through iterative cycles, binds, dimerizes, and cleaves slipped DNAs, yielding striking exo-nuclease pauses along slip-outs: 5'-C↓A↓GC↓A↓G-3' and 5'-C↓T↓G↓C↓T↓G-3'. CAG excision is slower than CTG and requires intra-strand A·A and T·T mismatches. Fully paired hairpins arrested excision, whereas disease-delaying CAA interruptions further slowed excision. Endo-nucleolytic cleavage is insensitive to slip-outs. Rare FAN1 variants are found in individuals with autism with CGG/CCG expansions, and CGG/CCG slip-outs show exo-nuclease pauses. The slip-out-specific ligand, naphthyridine-azaquinolone, which induces contractions of expanded repeats in vivo, requires FAN1 for its effect, and protects slip-outs from FAN1 exo-, but not endo-, nucleolytic digestion. FAN1's inchworm pausing of slip-out excision rates is well suited to modify inchworm expansion rates, which modify disease onset and progression.
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Affiliation(s)
- Amit Laxmikant Deshmukh
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Marie-Christine Caron
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, QC G1R 3S3, Canada; Department of Molecular Biology, Medical Biochemistry, and Pathology, Laval University Cancer Research Center, Québec City, QC G1R 3S3, Canada
| | - Mohiuddin Mohiuddin
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Stella Lanni
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Gagan B Panigrahi
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Mahreen Khan
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Worrawat Engchuan
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Natalie Shum
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Aisha Faruqui
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Peixiang Wang
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Ryan K C Yuen
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Kazuhiko Nakatani
- Department of Regulatory Bioorganic Chemistry, the Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, QC G1R 3S3, Canada; Department of Molecular Biology, Medical Biochemistry, and Pathology, Laval University Cancer Research Center, Québec City, QC G1R 3S3, Canada
| | - Christopher E Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, PGCRL, Toronto, Canada, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Program of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
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19
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Foster B, Attwood M, Gibbs-Seymour I. Tools for Decoding Ubiquitin Signaling in DNA Repair. Front Cell Dev Biol 2021; 9:760226. [PMID: 34950659 PMCID: PMC8690248 DOI: 10.3389/fcell.2021.760226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/09/2021] [Indexed: 12/21/2022] Open
Abstract
The maintenance of genome stability requires dedicated DNA repair processes and pathways that are essential for the faithful duplication and propagation of chromosomes. These DNA repair mechanisms counteract the potentially deleterious impact of the frequent genotoxic challenges faced by cells from both exogenous and endogenous agents. Intrinsic to these mechanisms, cells have an arsenal of protein factors that can be utilised to promote repair processes in response to DNA lesions. Orchestration of the protein factors within the various cellular DNA repair pathways is performed, in part, by post-translational modifications, such as phosphorylation, ubiquitin, SUMO and other ubiquitin-like modifiers (UBLs). In this review, we firstly explore recent advances in the tools for identifying factors involved in both DNA repair and ubiquitin signaling pathways. We then expand on this by evaluating the growing repertoire of proteomic, biochemical and structural techniques available to further understand the mechanistic basis by which these complex modifications regulate DNA repair. Together, we provide a snapshot of the range of methods now available to investigate and decode how ubiquitin signaling can promote DNA repair and maintain genome stability in mammalian cells.
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Affiliation(s)
| | | | - Ian Gibbs-Seymour
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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20
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Bamberger C, Pankow S, Yates JR. SMG1 and CDK12 Link ΔNp63α Phosphorylation to RNA Surveillance in Keratinocytes. J Proteome Res 2021; 20:5347-5358. [PMID: 34761935 PMCID: PMC10653645 DOI: 10.1021/acs.jproteome.1c00427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The tumor suppressor p53-like protein p63 is required for self-renewal of epidermal tissues. Loss of p63 or exposure to ultraviolet (UV) irradiation triggers terminal differentiation in keratinocytes. However, it remains unclear how p63 diverts epidermal cells from proliferation to terminal differentiation, thereby contributing to successful tissue self-renewal. Here, we used bottom-up proteomics to identify the proteome at the chromatin in normal human epidermal keratinocytes following UV irradiation and p63 depletion. We found that loss of p63 increased DNA damage and that UV irradiation recruited the cyclin-dependent kinase CDK12 and the serine/threonine protein kinase SMG1 to chromatin only in the presence of p63. A post-translational modification analysis of ΔNp63α with mass spectrometry revealed that phosphorylation of T357/S358 and S368 was dependent on SMG1, whereas CDK12 increased the phosphorylation of ΔNp63α at S66/S68 and S301. Indirect phosphorylation of ΔNp63α in the presence of SMG1 enabled ΔNp63α to bind to the tumor suppressor p53-specific DNA recognition sequence, whereas CDK12 rendered ΔNp63α less responsive to UV irradiation and was not required for specific DNA binding. CDK12 and SMG1 are known to regulate the transcription and splicing of RNAs and the decay of nonsense RNAs, respectively, and a subset of p63-specific protein-protein interactions at the chromatin also linked p63 to RNA transcription and decay. We observed that in the absence of p63, UV irradiation resulted in more ORF1p. ORF1p is the first protein product of the intronless non-LTR retrotransposon LINE-1, indicating a derailed surveillance of RNA processing and/or translation. Our results suggest that p63 phosphorylation and transcriptional activation might correspond to altered RNA processing and/or translation to protect proliferating keratinocytes from increased genotoxic stress.
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Affiliation(s)
- Casimir Bamberger
- Department for Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Sandra Pankow
- Department for Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - John R. Yates
- Department for Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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21
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Zhao X, Lu H, Usdin K. FAN1's protection against CGG repeat expansion requires its nuclease activity and is FANCD2-independent. Nucleic Acids Res 2021; 49:11643-11652. [PMID: 34718701 PMCID: PMC8599916 DOI: 10.1093/nar/gkab899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 09/20/2021] [Accepted: 10/12/2021] [Indexed: 12/21/2022] Open
Abstract
The Repeat Expansion Diseases, a large group of human diseases that includes the fragile X-related disorders (FXDs) and Huntington's disease (HD), all result from expansion of a disease-specific microsatellite via a mechanism that is not fully understood. We have previously shown that mismatch repair (MMR) proteins are required for expansion in a mouse model of the FXDs, but that the FANCD2 and FANCI associated nuclease 1 (FAN1), a component of the Fanconi anemia (FA) DNA repair pathway, is protective. FAN1's nuclease activity has been reported to be dispensable for protection against expansion in an HD cell model. However, we show here that in a FXD mouse model a point mutation in the nuclease domain of FAN1 has the same effect on expansion as a null mutation. Furthermore, we show that FAN1 and another nuclease, EXO1, have an additive effect in protecting against MSH3-dependent expansions. Lastly, we show that the loss of FANCD2, a vital component of the Fanconi anemia DNA repair pathway, has no effect on expansions. Thus, FAN1 protects against MSH3-dependent expansions without diverting the expansion intermediates into the canonical FA pathway and this protection depends on FAN1 having an intact nuclease domain.
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Affiliation(s)
- Xiaonan Zhao
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Huiyan Lu
- Laboratory Animal Sciences section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Karen Usdin
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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22
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Abstract
At fifteen different genomic locations, the expansion of a CAG/CTG repeat causes a neurodegenerative or neuromuscular disease, the most common being Huntington's disease and myotonic dystrophy type 1. These disorders are characterized by germline and somatic instability of the causative CAG/CTG repeat mutations. Repeat lengthening, or expansion, in the germline leads to an earlier age of onset or more severe symptoms in the next generation. In somatic cells, repeat expansion is thought to precipitate the rate of disease. The mechanisms underlying repeat instability are not well understood. Here we review the mammalian model systems that have been used to study CAG/CTG repeat instability, and the modifiers identified in these systems. Mouse models have demonstrated prominent roles for proteins in the mismatch repair pathway as critical drivers of CAG/CTG instability, which is also suggested by recent genome-wide association studies in humans. We draw attention to a network of connections between modifiers identified across several systems that might indicate pathway crosstalk in the context of repeat instability, and which could provide hypotheses for further validation or discovery. Overall, the data indicate that repeat dynamics might be modulated by altering the levels of DNA metabolic proteins, their regulation, their interaction with chromatin, or by direct perturbation of the repeat tract. Applying novel methodologies and technologies to this exciting area of research will be needed to gain deeper mechanistic insight that can be harnessed for therapies aimed at preventing repeat expansion or promoting repeat contraction.
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Affiliation(s)
- Vanessa C. Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA,Department of Neurology, Harvard Medical School, Boston, MA, USA,Correspondence to: Vanessa C. Wheeler, Center for Genomic Medicine, Massachusetts Hospital, Boston MAA 02115, USA. E-mail: . and Vincent Dion, UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. E-mail:
| | - Vincent Dion
- UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK,Correspondence to: Vanessa C. Wheeler, Center for Genomic Medicine, Massachusetts Hospital, Boston MAA 02115, USA. E-mail: . and Vincent Dion, UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. E-mail:
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23
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Hussmann JA, Ling J, Ravisankar P, Yan J, Cirincione A, Xu A, Simpson D, Yang D, Bothmer A, Cotta-Ramusino C, Weissman JS, Adamson B. Mapping the genetic landscape of DNA double-strand break repair. Cell 2021; 184:5653-5669.e25. [PMID: 34672952 PMCID: PMC9074467 DOI: 10.1016/j.cell.2021.10.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/31/2021] [Accepted: 09/29/2021] [Indexed: 12/20/2022]
Abstract
Cells repair DNA double-strand breaks (DSBs) through a complex set of pathways critical for maintaining genomic integrity. To systematically map these pathways, we developed a high-throughput screening approach called Repair-seq that measures the effects of thousands of genetic perturbations on mutations introduced at targeted DNA lesions. Using Repair-seq, we profiled DSB repair products induced by two programmable nucleases (Cas9 and Cas12a) in the presence or absence of oligonucleotides for homology-directed repair (HDR) after knockdown of 476 genes involved in DSB repair or associated processes. The resulting data enabled principled, data-driven inference of DSB end joining and HDR pathways. Systematic interrogation of this data uncovered unexpected relationships among DSB repair genes and demonstrated that repair outcomes with superficially similar sequence architectures can have markedly different genetic dependencies. This work provides a foundation for mapping DNA repair pathways and for optimizing genome editing across diverse modalities.
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Affiliation(s)
- Jeffrey A Hussmann
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Jia Ling
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Purnima Ravisankar
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Jun Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Ann Cirincione
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Albert Xu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Danny Simpson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Dian Yang
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | | | | | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Britt Adamson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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24
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Goold R, Hamilton J, Menneteau T, Flower M, Bunting EL, Aldous SG, Porro A, Vicente JR, Allen ND, Wilkinson H, Bates GP, Sartori AA, Thalassinos K, Balmus G, Tabrizi SJ. FAN1 controls mismatch repair complex assembly via MLH1 retention to stabilize CAG repeat expansion in Huntington's disease. Cell Rep 2021; 36:109649. [PMID: 34469738 PMCID: PMC8424649 DOI: 10.1016/j.celrep.2021.109649] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/30/2021] [Accepted: 08/11/2021] [Indexed: 11/18/2022] Open
Abstract
CAG repeat expansion in the HTT gene drives Huntington's disease (HD) pathogenesis and is modulated by DNA damage repair pathways. In this context, the interaction between FAN1, a DNA-structure-specific nuclease, and MLH1, member of the DNA mismatch repair pathway (MMR), is not defined. Here, we identify a highly conserved SPYF motif at the N terminus of FAN1 that binds to MLH1. Our data support a model where FAN1 has two distinct functions to stabilize CAG repeats. On one hand, it binds MLH1 to restrict its recruitment by MSH3, thus inhibiting the assembly of a functional MMR complex that would otherwise promote CAG repeat expansion. On the other hand, it promotes accurate repair via its nuclease activity. These data highlight a potential avenue for HD therapeutics in attenuating somatic expansion.
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Affiliation(s)
- Robert Goold
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; UK Dementia Research Institute, University College London, London WC1N 3BG, UK
| | - Joseph Hamilton
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; UK Dementia Research Institute, University College London, London WC1N 3BG, UK
| | - Thomas Menneteau
- UK Dementia Research Institute, University College London, London WC1N 3BG, UK; Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - Michael Flower
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; UK Dementia Research Institute, University College London, London WC1N 3BG, UK
| | - Emma L Bunting
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Sarah G Aldous
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; UK Dementia Research Institute, University College London, London WC1N 3BG, UK
| | - Antonio Porro
- Institute of Molecular Cancer Research, University of Zurich, Zurich 8057, Switzerland
| | - José R Vicente
- UK Dementia Research Institute, University of Cambridge, Cambridge CB2 0AH, UK
| | | | | | - Gillian P Bates
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; UK Dementia Research Institute, University College London, London WC1N 3BG, UK
| | - Alessandro A Sartori
- Institute of Molecular Cancer Research, University of Zurich, Zurich 8057, Switzerland
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK; Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, UK
| | - Gabriel Balmus
- UK Dementia Research Institute, University of Cambridge, Cambridge CB2 0AH, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AH, UK.
| | - Sarah J Tabrizi
- UCL Huntington's Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; UK Dementia Research Institute, University College London, London WC1N 3BG, UK.
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25
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Loupe JM, Pinto RM, Kim KH, Gillis T, Mysore JS, Andrew MA, Kovalenko M, Murtha R, Seong I, Gusella JF, Kwak S, Howland D, Lee R, Lee JM, Wheeler VC, MacDonald ME. Promotion of somatic CAG repeat expansion by Fan1 knock-out in Huntington's disease knock-in mice is blocked by Mlh1 knock-out. Hum Mol Genet 2021; 29:3044-3053. [PMID: 32876667 PMCID: PMC7645713 DOI: 10.1093/hmg/ddaa196] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/20/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022] Open
Abstract
Recent genome-wide association studies of age-at-onset in Huntington’s disease (HD) point to distinct modes of potential disease modification: altering the rate of somatic expansion of the HTT CAG repeat or altering the resulting CAG threshold length-triggered toxicity process. Here, we evaluated the mouse orthologs of two HD age-at-onset modifier genes, FAN1 and RRM2B, for an influence on somatic instability of the expanded CAG repeat in Htt CAG knock-in mice. Fan1 knock-out increased somatic expansion of Htt CAG repeats, in the juvenile- and the adult-onset HD ranges, whereas knock-out of Rrm2b did not greatly alter somatic Htt CAG repeat instability. Simultaneous knock-out of Mlh1, the ortholog of a third HD age-at-onset modifier gene (MLH1), which suppresses somatic expansion of the Htt knock-in CAG repeat, blocked the Fan1 knock-out-induced acceleration of somatic CAG expansion. This genetic interaction indicates that functional MLH1 is required for the CAG repeat destabilizing effect of FAN1 loss. Thus, in HD, it is uncertain whether the RRM2B modifier effect on timing of onset may be due to a DNA instability mechanism. In contrast, the FAN1 modifier effects reveal that functional FAN1 acts to suppress somatic CAG repeat expansion, likely in genetic interaction with other DNA instability modifiers whose combined effects can hasten or delay onset and other CAG repeat length-driven phenotypes.
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Affiliation(s)
- Jacob M Loupe
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Ricardo Mouro Pinto
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Kyung-Hee Kim
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Tammy Gillis
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jayalakshmi S Mysore
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Marissa A Andrew
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Marina Kovalenko
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Ryan Murtha
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - IhnSik Seong
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.,Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.,Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
| | - Seung Kwak
- CHDI Foundation, Princeton, NJ 08540, USA
| | | | - Ramee Lee
- CHDI Foundation, Princeton, NJ 08540, USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Vanessa C Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Marcy E MacDonald
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.,Medical and Population Genetics Program, The Broad Institute of M.I.T. and Harvard, Cambridge, MA 02142, USA
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26
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Kratz K, Artola-Borán M, Kobayashi-Era S, Koh G, Oliveira G, Kobayashi S, Oliveira A, Zou X, Richter J, Tsuda M, Sasanuma H, Takeda S, Loizou JI, Sartori AA, Nik-Zainal S, Jiricny J. FANCD2-Associated Nuclease 1 Partially Compensates for the Lack of Exonuclease 1 in Mismatch Repair. Mol Cell Biol 2021; 41:e0030321. [PMID: 34228493 PMCID: PMC8384067 DOI: 10.1128/mcb.00303-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 06/28/2021] [Indexed: 11/20/2022] Open
Abstract
Germline mutations in the mismatch repair (MMR) genes MSH2, MSH6, MLH1, and PMS2 are linked to cancer of the colon and other organs, characterized by microsatellite instability and a large increase in mutation frequency. Unexpectedly, mutations in EXO1, encoding the only exonuclease genetically implicated in MMR, are not linked to familial cancer and cause a substantially weaker mutator phenotype. This difference could be explained if eukaryotic cells possessed additional exonucleases redundant with EXO1. Analysis of the MLH1 interactome identified FANCD2-associated nuclease 1 (FAN1), a novel enzyme with biochemical properties resembling EXO1. We now show that FAN1 efficiently substitutes for EXO1 in MMR assays and that this functional complementation is modulated by its interaction with MLH1. FAN1 also contributes to MMR in vivo; cells lacking both EXO1 and FAN1 have an MMR defect and display resistance to N-methyl-N-nitrosourea (MNU) and 6-thioguanine (TG). Moreover, FAN1 loss amplifies the mutational profile of EXO1-deficient cells, suggesting that the two nucleases act redundantly in the same antimutagenic pathway. However, the increased drug resistance and mutator phenotype of FAN1/EXO1-deficient cells are less prominent than those seen in cells lacking MSH6 or MLH1. Eukaryotic cells thus apparently possess additional mechanisms that compensate for the loss of EXO1.
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Affiliation(s)
- Katja Kratz
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Mariela Artola-Borán
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Saho Kobayashi-Era
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Gene Koh
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Academic Department of Medical Genetics, The Clinical School, University of Cambridge, Cambridge, United Kingdom
- MRC Cancer Unit, The Clinical School, University of Cambridge, Cambridge, United Kingdom
| | - Goncalo Oliveira
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Centre, Medical University of Vienna, Vienna, Austria
| | - Shunsuke Kobayashi
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Andreia Oliveira
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Xueqing Zou
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Academic Department of Medical Genetics, The Clinical School, University of Cambridge, Cambridge, United Kingdom
- MRC Cancer Unit, The Clinical School, University of Cambridge, Cambridge, United Kingdom
| | - Julia Richter
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Sasanuma
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Joanna I. Loizou
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Centre, Medical University of Vienna, Vienna, Austria
| | | | - Serena Nik-Zainal
- Academic Department of Medical Genetics, The Clinical School, University of Cambridge, Cambridge, United Kingdom
- MRC Cancer Unit, The Clinical School, University of Cambridge, Cambridge, United Kingdom
| | - Josef Jiricny
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
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27
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Porro A, Mohiuddin M, Zurfluh C, Spegg V, Dai J, Iehl F, Ropars V, Collotta G, Fishwick KM, Mozaffari NL, Guérois R, Jiricny J, Altmeyer M, Charbonnier JB, Pearson CE, Sartori AA. FAN1-MLH1 interaction affects repair of DNA interstrand cross-links and slipped-CAG/CTG repeats. SCIENCE ADVANCES 2021; 7:7/31/eabf7906. [PMID: 34330701 PMCID: PMC8324060 DOI: 10.1126/sciadv.abf7906] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 06/15/2021] [Indexed: 05/05/2023]
Abstract
FAN1, a DNA structure-specific nuclease, interacts with MLH1, but the repair pathways in which this complex acts are unknown. FAN1 processes DNA interstrand crosslinks (ICLs) and FAN1 variants are modifiers of the neurodegenerative Huntington's disease (HD), presumably by regulating HD-causing CAG repeat expansions. Here, we identify specific amino acid residues in two adjacent FAN1 motifs that are critical for MLH1 binding. Disruption of the FAN1-MLH1 interaction confers cellular hypersensitivity to ICL damage and defective repair of CAG/CTG slip-outs, intermediates of repeat expansion mutations. FAN1-S126 phosphorylation, which hinders FAN1-MLH1 association, is cell cycle-regulated by cyclin-dependent kinase activity and attenuated upon ICL induction. Our data highlight the FAN1-MLH1 complex as a phosphorylation-regulated determinant of ICL response and repeat stability, opening novel paths to modify cancer and neurodegeneration.
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Affiliation(s)
- Antonio Porro
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Mohiuddin Mohiuddin
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Christina Zurfluh
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Vincent Spegg
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Jingqi Dai
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Florence Iehl
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Virginie Ropars
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Giulio Collotta
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Keri M Fishwick
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Nour L Mozaffari
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Raphaël Guérois
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Josef Jiricny
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Jean-Baptiste Charbonnier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Christopher E Pearson
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
- Program of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alessandro A Sartori
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
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28
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Rejeb I, Jerbi M, Jilani H, Gaied H, Elaribi Y, Hizem S, Aoudia R, Hedri H, Zaied C, Abid S, Bacha H, BenAbdallah T, BenJemaa L, Goucha R. New familial cases of karyomegalic interstitial nephritis with mutations in the FAN1 gene. BMC Med Genomics 2021; 14:160. [PMID: 34126972 PMCID: PMC8201669 DOI: 10.1186/s12920-021-01009-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 06/07/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Karyomegalic interstitial nephritis (KIN) is a rare disease entity first described by Burry in 1974. The term KIN was introduced by Mihatsch et al. in 1979. KIN is characterized by chronic tubulointerstitial nephritis associated with enlarged tubular epithelial cell nuclei, which leads to a progressive decline of renal function. The prevalence of this disease is less than 1% of all biopsies, and its pathogenesis is unclear. KIN results from mutations in FAN1 (FANCD2/FANCI-Associated Nuclease 1), a gene involved in the DNA damage response pathway, particularly in the kidney. In this study, we report two Tunisian consanguineous families with KIN caused by mutations in the FAN1 gene. METHODS Direct sequencing of the coding regions and flanking intronic sequences of the FAN1 gene was performed in three affected members. Three prediction programs (Polyphen-2 software, SIFT, and MutationTaster) were used to predict the functional effect of the detected variations. RESULTS Two causative frameshift variants in the FAN1 gene were identified in each family: The previously described frameshift mutation c.2616delA (p.Asp873ThrfsTer17) and a novel mutation c.2603delT (p.Leu868ArgfsTer22) classified as "pathogenic" according to the American College of Medical Genetics and Genomics (ACMG) guidelines. CONCLUSION To our best knowledge, this is the first Tunisian study involving familial cases of KIN with mutations in the FAN1 gene. We hypothesize that these findings can expand the mutational spectrum of KIN and provide valuable information on the genetic cause of KIN.
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Affiliation(s)
- Imen Rejeb
- Service des Maladies Congénitales et Héréditaires, CHU Mongi Slim La Marsa, La Marsa, Tunisia.
| | - Mouna Jerbi
- Service de Néphrologie, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Laboratory of Renal Pathology LR00SP01, Tunis, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
| | - Houweyda Jilani
- Service des Maladies Congénitales et Héréditaires, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
| | - Hanène Gaied
- Service de Néphrologie, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Laboratory of Renal Pathology LR00SP01, Tunis, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
| | - Yasmina Elaribi
- Service des Maladies Congénitales et Héréditaires, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
| | - Syrine Hizem
- Service des Maladies Congénitales et Héréditaires, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
| | - Raja Aoudia
- Laboratory of Renal Pathology LR00SP01, Tunis, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
- Department of Internal Medicine, Charles Nicolle Hospital, Tunis, Tunisia
| | - Hafedh Hedri
- Laboratory of Renal Pathology LR00SP01, Tunis, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
- Department of Internal Medicine, Charles Nicolle Hospital, Tunis, Tunisia
| | | | | | | | - Taieb BenAbdallah
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
- Department of Internal Medicine, Charles Nicolle Hospital, Tunis, Tunisia
| | - Lamia BenJemaa
- Service des Maladies Congénitales et Héréditaires, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
| | - Rim Goucha
- Service de Néphrologie, CHU Mongi Slim La Marsa, La Marsa, Tunisia
- Laboratory of Renal Pathology LR00SP01, Tunis, Tunisia
- Faculty of Medicine, University Tunis El Manar, Tunis, Tunisia
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Structural insight into FANCI-FANCD2 monoubiquitination. Essays Biochem 2021; 64:807-817. [PMID: 32725171 PMCID: PMC7588663 DOI: 10.1042/ebc20200001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/10/2020] [Accepted: 07/07/2020] [Indexed: 12/13/2022]
Abstract
The Fanconi anemia (FA) pathway coordinates a faithful repair mechanism for DNA damage that blocks DNA replication, such as interstrand cross-links. A key step in the FA pathway is the conjugation of ubiquitin on to FANCD2 and FANCI, which is facilitated by a large E3 ubiquitin ligase complex called the FA core complex. Mutations in FANCD2, FANCI or FA core complex components cause the FA bone marrow failure syndrome. Despite the importance of these proteins to DNA repair and human disease, our molecular understanding of the FA pathway has been limited due to a deficit in structural studies. With the recent development in cryo-electron microscopy (EM), significant advances have been made in structural characterization of these proteins in the last 6 months. These structures, combined with new biochemical studies, now provide a more detailed understanding of how FANCD2 and FANCI are monoubiquitinated and how DNA repair may occur. In this review, we summarize these recent advances in the structural and molecular understanding of these key components in the FA pathway, compare the activation steps of FANCD2 and FANCI monoubiquitination and suggest molecular steps that are likely to be involved in regulating its activity.
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30
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Tye S, Ronson GE, Morris JR. A fork in the road: Where homologous recombination and stalled replication fork protection part ways. Semin Cell Dev Biol 2021; 113:14-26. [PMID: 32653304 PMCID: PMC8082280 DOI: 10.1016/j.semcdb.2020.07.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/06/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022]
Abstract
In response to replication hindrances, DNA replication forks frequently stall and are remodelled into a four-way junction. In such a structure the annealed nascent strand is thought to resemble a DNA double-strand break and remodelled forks are vulnerable to nuclease attack by MRE11 and DNA2. Proteins that promote the recruitment, loading and stabilisation of RAD51 onto single-stranded DNA for homology search and strand exchange in homologous recombination (HR) repair and inter-strand cross-link repair also act to set up RAD51-mediated protection of nascent DNA at stalled replication forks. However, despite the similarities of these pathways, several lines of evidence indicate that fork protection is not simply analogous to the RAD51 loading step of HR. Protection of stalled forks not only requires separate functions of a number of recombination proteins, but also utilises nucleases important for the resection steps of HR in alternative ways. Here we discuss how fork protection arises and how its differences with HR give insights into the differing contexts of these two pathways.
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Affiliation(s)
- Stephanie Tye
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, SW7 2AZ, UK
| | - George E Ronson
- University of Birmingham, College of Medical Dental Schools, Institute of Cancer and Genomics Sciences, Birmingham Centre for Genome Biology, Vincent Drive, Edgbaston, Birmingham, B15 2TT, UK
| | - Joanna R Morris
- University of Birmingham, College of Medical Dental Schools, Institute of Cancer and Genomics Sciences, Birmingham Centre for Genome Biology, Vincent Drive, Edgbaston, Birmingham, B15 2TT, UK.
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31
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Zhang S, Zhang X, Purmann C, Ma S, Shrestha A, Davis KN, Ho M, Huang Y, Pattni R, Hung Wong W, Bernstein JA, Hallmayer J, Urban AE. Network Effects of the 15q13.3 Microdeletion on the Transcriptome and Epigenome in Human-Induced Neurons. Biol Psychiatry 2021; 89:497-509. [PMID: 32919612 PMCID: PMC9359316 DOI: 10.1016/j.biopsych.2020.06.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND The 15q13.3 microdeletion is associated with several neuropsychiatric disorders, including autism and schizophrenia. Previous association and functional studies have investigated the potential role of several genes within the deletion in neuronal dysfunction, but the molecular effects of the deletion as a whole remain largely unknown. METHODS Induced pluripotent stem cells, from 3 patients with the 15q13.3 microdeletion and 3 control subjects, were generated and converted into induced neurons. We analyzed the effects of the 15q13.3 microdeletion on genome-wide gene expression, DNA methylation, chromatin accessibility, and sensitivity to cisplatin-induced DNA damage. Furthermore, we measured gene expression changes in induced neurons with CRISPR (clustered regularly interspaced short palindromic repeats) knockouts of individual 15q13.3 microdeletion genes. RESULTS In both induced pluripotent stem cells and induced neurons, gene copy number change within the 15q13.3 microdeletion was accompanied by significantly decreased gene expression and no compensatory changes in DNA methylation or chromatin accessibility, supporting the model that haploinsufficiency of genes within the deleted region drives the disorder. Furthermore, we observed global effects of the microdeletion on the transcriptome and epigenome, with disruptions in several neuropsychiatric disorder-associated pathways and gene families, including Wnt signaling, ribosome function, DNA binding, and clustered protocadherins. Individual gene knockouts mirrored many of the observed changes in an overlapping fashion between knockouts. CONCLUSIONS Our multiomics analysis of the 15q13.3 microdeletion revealed downstream effects in pathways previously associated with neuropsychiatric disorders and indications of interactions between genes within the deletion. This molecular systems analysis can be applied to other chromosomal aberrations to further our etiological understanding of neuropsychiatric disorders.
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Affiliation(s)
- Siming Zhang
- Department of Genetics, School of Humanities and Science, Stanford University, Stanford, California
| | - Xianglong Zhang
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Carolin Purmann
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Shining Ma
- Department of Pediatrics, School of Humanities and Sciences, Stanford University, Stanford, California
| | - Anima Shrestha
- School of Medicine, Stanford University, and Department of Statistics, School of Humanities and Sciences, Stanford University, Stanford, California
| | - Kasey N Davis
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Marcus Ho
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Yiling Huang
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Reenal Pattni
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Wing Hung Wong
- Department of Pediatrics, School of Humanities and Sciences, Stanford University, Stanford, California
| | - Jonathan A Bernstein
- Department of Human Biology, School of Humanities and Science, Stanford University, Stanford, California
| | - Joachim Hallmayer
- Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California
| | - Alexander E Urban
- Department of Genetics, School of Humanities and Science, Stanford University, Stanford, California; Department of Psychiatry and Behavioral Sciences, School of Humanities and Science, Stanford University, Stanford, California.
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Abstract
DNA mismatch repair (MMR) is a highly conserved genome stabilizing pathway that corrects DNA replication errors, limits chromosomal rearrangements, and mediates the cellular response to many types of DNA damage. Counterintuitively, MMR is also involved in the generation of mutations, as evidenced by its role in causing somatic triplet repeat expansion in Huntington’s disease (HD) and other neurodegenerative disorders. In this review, we discuss the current state of mechanistic knowledge of MMR and review the roles of key enzymes in this pathway. We also present the evidence for mutagenic function of MMR in CAG repeat expansion and consider mechanistic hypotheses that have been proposed. Understanding the role of MMR in CAG expansion may shed light on potential avenues for therapeutic intervention in HD.
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Affiliation(s)
- Ravi R Iyer
- CHDI Management/CHDI Foundation, Princeton, NJ, USA
| | - Anna Pluciennik
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
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33
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Zhao X, Kumari D, Miller CJ, Kim GY, Hayward B, Vitalo AG, Pinto RM, Usdin K. Modifiers of Somatic Repeat Instability in Mouse Models of Friedreich Ataxia and the Fragile X-Related Disorders: Implications for the Mechanism of Somatic Expansion in Huntington's Disease. J Huntingtons Dis 2021; 10:149-163. [PMID: 33579860 PMCID: PMC7990428 DOI: 10.3233/jhd-200423] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Huntington's disease (HD) is one of a large group of human disorders that are caused by expanded DNA repeats. These repeat expansion disorders can have repeat units of different size and sequence that can be located in any part of the gene and, while the pathological consequences of the expansion can differ widely, there is evidence to suggest that the underlying mutational mechanism may be similar. In the case of HD, the expanded repeat unit is a CAG trinucleotide located in exon 1 of the huntingtin (HTT) gene, resulting in an expanded polyglutamine tract in the huntingtin protein. Expansion results in neuronal cell death, particularly in the striatum. Emerging evidence suggests that somatic CAG expansion, specifically expansion occurring in the brain during the lifetime of an individual, contributes to an earlier disease onset and increased severity. In this review we will discuss mouse models of two non-CAG repeat expansion diseases, specifically the Fragile X-related disorders (FXDs) and Friedreich ataxia (FRDA). We will compare and contrast these models with mouse and patient-derived cell models of various other repeat expansion disorders and the relevance of these findings for somatic expansion in HD. We will also describe additional genetic factors and pathways that modify somatic expansion in the FXD mouse model for which no comparable data yet exists in HD mice or humans. These additional factors expand the potential druggable space for diseases like HD where somatic expansion is a significant contributor to disease impact.
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Affiliation(s)
- Xiaonan Zhao
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Daman Kumari
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Carson J Miller
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Geum-Yi Kim
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bruce Hayward
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Antonia G Vitalo
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Ricardo Mouro Pinto
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Karen Usdin
- Laboratory of Cell and Molecular Biology, National Institutes of Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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Gartner A, Engebrecht J. DNA repair, recombination, and damage signaling. Genetics 2021; 220:6522877. [PMID: 35137093 PMCID: PMC9097270 DOI: 10.1093/genetics/iyab178] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/10/2021] [Indexed: 01/09/2023] Open
Abstract
DNA must be accurately copied and propagated from one cell division to the next, and from one generation to the next. To ensure the faithful transmission of the genome, a plethora of distinct as well as overlapping DNA repair and recombination pathways have evolved. These pathways repair a large variety of lesions, including alterations to single nucleotides and DNA single and double-strand breaks, that are generated as a consequence of normal cellular function or by external DNA damaging agents. In addition to the proteins that mediate DNA repair, checkpoint pathways have also evolved to monitor the genome and coordinate the action of various repair pathways. Checkpoints facilitate repair by mediating a transient cell cycle arrest, or through initiation of cell suicide if DNA damage has overwhelmed repair capacity. In this chapter, we describe the attributes of Caenorhabditis elegans that facilitate analyses of DNA repair, recombination, and checkpoint signaling in the context of a whole animal. We review the current knowledge of C. elegans DNA repair, recombination, and DNA damage response pathways, and their role during development, growth, and in the germ line. We also discuss how the analysis of mutational signatures in C. elegans is helping to inform cancer mutational signatures in humans.
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Affiliation(s)
- Anton Gartner
- Department for Biological Sciences, IBS Center for Genomic Integrity, Ulsan National Institute of Science and Technology, Ulsan 689-798, Republic of Korea,Corresponding author: (A.G.); (J.E.)
| | - JoAnne Engebrecht
- Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, USA,Corresponding author: (A.G.); (J.E.)
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Morozko EL, Smith-Geater C, Monteys AM, Pradhan S, Lim RG, Langfelder P, Kachemov M, Kulkarni JA, Zaifman J, Hill A, Stocksdale JT, Cullis PR, Wu J, Ochaba J, Miramontes R, Chakraborty A, Hazra TK, Lau A, St-Cyr S, Orellana I, Kopan L, Wang KQ, Yeung S, Leavitt BR, Reidling JC, Yang XW, Steffan JS, Davidson BL, Sarkar PS, Thompson LM. PIAS1 modulates striatal transcription, DNA damage repair, and SUMOylation with relevance to Huntington's disease. Proc Natl Acad Sci U S A 2021; 118:e2021836118. [PMID: 33468657 PMCID: PMC7848703 DOI: 10.1073/pnas.2021836118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
DNA damage repair genes are modifiers of disease onset in Huntington's disease (HD), but how this process intersects with associated disease pathways remains unclear. Here we evaluated the mechanistic contributions of protein inhibitor of activated STAT-1 (PIAS1) in HD mice and HD patient-derived induced pluripotent stem cells (iPSCs) and find a link between PIAS1 and DNA damage repair pathways. We show that PIAS1 is a component of the transcription-coupled repair complex, that includes the DNA damage end processing enzyme polynucleotide kinase-phosphatase (PNKP), and that PIAS1 is a SUMO E3 ligase for PNKP. Pias1 knockdown (KD) in HD mice had a normalizing effect on HD transcriptional dysregulation associated with synaptic function and disease-associated transcriptional coexpression modules enriched for DNA damage repair mechanisms as did reduction of PIAS1 in HD iPSC-derived neurons. KD also restored mutant HTT-perturbed enzymatic activity of PNKP and modulated genomic integrity of several transcriptionally normalized genes. The findings here now link SUMO modifying machinery to DNA damage repair responses and transcriptional modulation in neurodegenerative disease.
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Affiliation(s)
- Eva L Morozko
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697
| | - Charlene Smith-Geater
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
| | - Alejandro Mas Monteys
- Raymond G. Perelman Center for Cell and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Subrata Pradhan
- Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555
| | - Ryan G Lim
- Institute of Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697
| | - Peter Langfelder
- Department of Human Genetics, David Geffen School of Medicine at University of California, Los Angeles, CA 90095
| | - Marketta Kachemov
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697
| | - Jayesh A Kulkarni
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Josh Zaifman
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada V6T 1Z1
| | - Austin Hill
- Incisive Genetics Inc., Vancouver, BC, Canada V6A 0H9
| | | | - Pieter R Cullis
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
- NanoMedicines Innovation Network, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Jie Wu
- Department of Biological Chemistry, University of California, Irvine, CA 92697
| | - Joseph Ochaba
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697
| | - Ricardo Miramontes
- Institute of Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697
| | - Anirban Chakraborty
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555
| | - Tapas K Hazra
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555
| | - Alice Lau
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
| | - Sophie St-Cyr
- Raymond G. Perelman Center for Cell and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
| | - Iliana Orellana
- Sue and Bill Gross Stem Cell Institute, University of California, Irvine, CA 92697
| | - Lexi Kopan
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
| | - Keona Q Wang
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
| | - Sylvia Yeung
- Institute of Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Jack C Reidling
- Institute of Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697
| | - X William Yang
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA 90095
| | - Joan S Steffan
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
- Institute of Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697
| | - Beverly L Davidson
- Raymond G. Perelman Center for Cell and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Partha S Sarkar
- Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555
| | - Leslie M Thompson
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697;
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
- Institute of Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697
- Department of Biological Chemistry, University of California, Irvine, CA 92697
- Sue and Bill Gross Stem Cell Institute, University of California, Irvine, CA 92697
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36
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Schlam‐Babayov S, Bensimon A, Harel M, Geiger T, Aebersold R, Ziv Y, Shiloh Y. Phosphoproteomics reveals novel modes of function and inter-relationships among PIKKs in response to genotoxic stress. EMBO J 2021; 40:e104400. [PMID: 33215756 PMCID: PMC7809795 DOI: 10.15252/embj.2020104400] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 08/13/2020] [Accepted: 10/12/2020] [Indexed: 01/10/2023] Open
Abstract
The DNA damage response (DDR) is a complex signaling network that relies on cascades of protein phosphorylation, which are initiated by three protein kinases of the family of PI3-kinase-related protein kinases (PIKKs): ATM, ATR, and DNA-PK. ATM is missing or inactivated in the genome instability syndrome, ataxia-telangiectasia (A-T). The relative shares of these PIKKs in the response to genotoxic stress and the functional relationships among them are central questions in the genome stability field. We conducted a comprehensive phosphoproteomic analysis in human wild-type and A-T cells treated with the double-strand break-inducing chemical, neocarzinostatin, and validated the results with the targeted proteomic technique, selected reaction monitoring. We also matched our results with 34 published screens for DDR factors, creating a valuable resource for identifying strong candidates for novel DDR players. We uncovered fine-tuned dynamics between the PIKKs following genotoxic stress, such as DNA-PK-dependent attenuation of ATM. In A-T cells, partial compensation for ATM absence was provided by ATR and DNA-PK, with distinct roles and kinetics. The results highlight intricate relationships between these PIKKs in the DDR.
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Affiliation(s)
- Sapir Schlam‐Babayov
- The David and Inez Myers Laboratory of Cancer GeneticsDepartment of Human Molecular Genetics and BiochemistryTel Aviv University School of MedicineTel AvivIsrael
| | - Ariel Bensimon
- Department of BiologyInstitute of Molecular Systems BiologyETH ZurichZurichSwitzerland
- Present address:
CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Michal Harel
- Department of Human Molecular Genetics and BiochemistryTel Aviv University School of MedicineTel AvivIsrael
| | - Tamar Geiger
- Department of Human Molecular Genetics and BiochemistryTel Aviv University School of MedicineTel AvivIsrael
| | - Ruedi Aebersold
- Department of BiologyInstitute of Molecular Systems BiologyETH ZurichZurichSwitzerland
- Faculty of ScienceUniversity of ZurichZurichSwitzerland
| | - Yael Ziv
- The David and Inez Myers Laboratory of Cancer GeneticsDepartment of Human Molecular Genetics and BiochemistryTel Aviv University School of MedicineTel AvivIsrael
| | - Yosef Shiloh
- The David and Inez Myers Laboratory of Cancer GeneticsDepartment of Human Molecular Genetics and BiochemistryTel Aviv University School of MedicineTel AvivIsrael
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Deshmukh AL, Porro A, Mohiuddin M, Lanni S, Panigrahi GB, Caron MC, Masson JY, Sartori AA, Pearson CE. FAN1, a DNA Repair Nuclease, as a Modifier of Repeat Expansion Disorders. J Huntingtons Dis 2021; 10:95-122. [PMID: 33579867 PMCID: PMC7990447 DOI: 10.3233/jhd-200448] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
FAN1 encodes a DNA repair nuclease. Genetic deficiencies, copy number variants, and single nucleotide variants of FAN1 have been linked to karyomegalic interstitial nephritis, 15q13.3 microdeletion/microduplication syndrome (autism, schizophrenia, and epilepsy), cancer, and most recently repeat expansion diseases. For seven CAG repeat expansion diseases (Huntington's disease (HD) and certain spinocerebellar ataxias), modification of age of onset is linked to variants of specific DNA repair proteins. FAN1 variants are the strongest modifiers. Non-coding disease-delaying FAN1 variants and coding disease-hastening variants (p.R507H and p.R377W) are known, where the former may lead to increased FAN1 levels and the latter have unknown effects upon FAN1 functions. Current thoughts are that ongoing repeat expansions in disease-vulnerable tissues, as individuals age, promote disease onset. Fan1 is required to suppress against high levels of ongoing somatic CAG and CGG repeat expansions in tissues of HD and FMR1 transgenic mice respectively, in addition to participating in DNA interstrand crosslink repair. FAN1 is also a modifier of autism, schizophrenia, and epilepsy. Coupled with the association of these diseases with repeat expansions, this suggests a common mechanism, by which FAN1 modifies repeat diseases. Yet how any of the FAN1 variants modify disease is unknown. Here, we review FAN1 variants, associated clinical effects, protein structure, and the enzyme's attributed functional roles. We highlight how variants may alter its activities in DNA damage response and/or repeat instability. A thorough awareness of the FAN1 gene and FAN1 protein functions will reveal if and how it may be targeted for clinical benefit.
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Affiliation(s)
- Amit L. Deshmukh
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Antonio Porro
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Mohiuddin Mohiuddin
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Stella Lanni
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Gagan B. Panigrahi
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
| | - Marie-Christine Caron
- Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, Quebec, Canada
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, Quebec, Canada
| | - Jean-Yves Masson
- Department of Molecular Biology, Medical Biochemistry and Pathology; Laval University Cancer Research Center, Québec City, Quebec, Canada
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, Quebec, Canada
| | | | - Christopher E. Pearson
- Program of Genetics & Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada
- University of Toronto, Program of Molecular Genetics, Toronto, Ontario, Canada
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New developments in Huntington's disease and other triplet repeat diseases: DNA repair turns to the dark side. Neuronal Signal 2020; 4:NS20200010. [PMID: 33224521 PMCID: PMC7672267 DOI: 10.1042/ns20200010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 02/08/2023] Open
Abstract
Huntington’s disease (HD) is a fatal, inherited neurodegenerative disease that causes neuronal death, particularly in medium spiny neurons. HD leads to serious and progressive motor, cognitive and psychiatric symptoms. Its genetic basis is an expansion of the CAG triplet repeat in the HTT gene, leading to extra glutamines in the huntingtin protein. HD is one of nine genetic diseases in this polyglutamine (polyQ) category, that also includes a number of inherited spinocerebellar ataxias (SCAs). Traditionally it has been assumed that HD age of onset and disease progression were solely the outcome of age-dependent exposure of neurons to toxic effects of the inherited mutant huntingtin protein. However, recent genome-wide association studies (GWAS) have revealed significant effects of genetic variants outside of HTT. Surprisingly, these variants turn out to be mostly in genes encoding DNA repair factors, suggesting that at least some disease modulation occurs at the level of the HTT DNA itself. These DNA repair proteins are known from model systems to promote ongoing somatic CAG repeat expansions in tissues affected by HD. Thus, for triplet repeats, some DNA repair proteins seem to abandon their normal genoprotective roles and, instead, drive expansions and accelerate disease. One attractive hypothesis—still to be proven rigorously—is that somatic HTT expansions augment the disease burden of the inherited allele. If so, therapeutic approaches that lower levels of huntingtin protein may need blending with additional therapies that reduce levels of somatic CAG repeat expansions to achieve maximal effect.
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Bassi G, Favalli N, Vuk M, Catalano M, Martinelli A, Trenner A, Porro A, Yang S, Tham CL, Moroglu M, Yue WW, Conway SJ, Vogt PK, Sartori AA, Scheuermann J, Neri D. A Single-Stranded DNA-Encoded Chemical Library Based on a Stereoisomeric Scaffold Enables Ligand Discovery by Modular Assembly of Building Blocks. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001970. [PMID: 33240760 PMCID: PMC7675038 DOI: 10.1002/advs.202001970] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/17/2020] [Indexed: 06/11/2023]
Abstract
A versatile and Lipinski-compliant DNA-encoded library (DEL), comprising 366 600 glutamic acid derivatives coupled to oligonucleotides serving as amplifiable identification barcodes is designed, constructed, and characterized. The GB-DEL library, constructed in single-stranded DNA format, allows de novo identification of specific binders against several pharmaceutically relevant proteins. Moreover, hybridization of the single-stranded DEL with a set of known protein ligands of low to medium affinity coupled to a complementary DNA strand results in self-assembled selectable chemical structures, leading to the identification of affinity-matured compounds.
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Affiliation(s)
- Gabriele Bassi
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
| | - Nicholas Favalli
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
| | - Miriam Vuk
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
| | - Marco Catalano
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
| | - Adriano Martinelli
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
| | - Anika Trenner
- Institute of Molecular Cancer ResearchUniversity of ZürichZürich8006Switzerland
| | - Antonio Porro
- Institute of Molecular Cancer ResearchUniversity of ZürichZürich8006Switzerland
| | - Su Yang
- Scripps Research InstituteDepartment of Molecular MedicineLa JollaCA92037USA
| | - Chuin Lean Tham
- Structural Genomic Consortium (SGC)Nuffield Department of MedicineUniversity of OxfordOxfordOX1 2JDUK
| | - Mustafa Moroglu
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Wyatt W. Yue
- Structural Genomic Consortium (SGC)Nuffield Department of MedicineUniversity of OxfordOxfordOX1 2JDUK
| | - Stuart J. Conway
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Peter K. Vogt
- Scripps Research InstituteDepartment of Molecular MedicineLa JollaCA92037USA
| | | | - Jörg Scheuermann
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
| | - Dario Neri
- Department of Chemistry and Applied BiosciencesETH ZürichZürich8092Switzerland
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40
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Tan W, Deans AJ. The ubiquitination machinery of the Fanconi Anemia DNA repair pathway. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 163:5-13. [PMID: 33058944 DOI: 10.1016/j.pbiomolbio.2020.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 10/23/2022]
Abstract
The Fanconi Anemia (FA) pathway maintains genome stability by preventing DNA damage from occurring when replication is blocked. Central to the FA pathway is the monoubiquitination of FANCI-FANCD2 mediated by a ubiquitin RING-E3 ligase complex called the FA core complex. Genetic mutation in any component of the FA core complex results in defective FANCI-FANCD2 monoubiquitination and phenotypes of DNA damage sensitivity, birth defects, early-onset bone marrow failure and cancer. Here, we discuss the mechanisms of the FA core complex and FANCI-FANCD2 monoubiquitination at sites of blocked replication and review our current understanding of the biological functions of these proteins in replication fork protection.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St, Fitzroy, Victoria, 3065, Australia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, 9 Princes St, Fitzroy, Victoria, 3065, Australia; Department of Medicine, St. Vincent's Health, The University of Melbourne, Australia. https://twitter.com/GenomeStability
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41
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Laverde EE, Lai Y, Leng F, Balakrishnan L, Freudenreich CH, Liu Y. R-loops promote trinucleotide repeat deletion through DNA base excision repair enzymatic activities. J Biol Chem 2020; 295:13902-13913. [PMID: 32763971 DOI: 10.1074/jbc.ra120.014161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/04/2020] [Indexed: 12/27/2022] Open
Abstract
Trinucleotide repeat (TNR) expansion and deletion are responsible for over 40 neurodegenerative diseases and associated with cancer. TNRs can undergo somatic instability that is mediated by DNA damage and repair and gene transcription. Recent studies have pointed toward a role for R-loops in causing TNR expansion and deletion, and it has been shown that base excision repair (BER) can result in CAG repeat deletion from R-loops in yeast. However, it remains unknown how BER in R-loops can mediate TNR instability. In this study, using biochemical approaches, we examined BER enzymatic activities and their influence on TNR R-loops. We found that AP endonuclease 1 incised an abasic site on the nontemplate strand of a TNR R-loop, creating a double-flap intermediate containing an RNA:DNA hybrid that subsequently inhibited polymerase β (pol β) synthesis of TNRs. This stimulated flap endonuclease 1 (FEN1) cleavage of TNRs engaged in an R-loop. Moreover, we showed that FEN1 also efficiently cleaved the RNA strand, facilitating pol β loop/hairpin bypass synthesis and the resolution of TNR R-loops through BER. Consequently, this resulted in fewer TNRs synthesized by pol β than those removed by FEN1, thereby leading to repeat deletion. Our results indicate that TNR R-loops preferentially lead to repeat deletion during BER by disrupting the balance between the addition and removal of TNRs. Our discoveries open a new avenue for the treatment and prevention of repeat expansion diseases and cancer.
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Affiliation(s)
- Eduardo E Laverde
- Biochemistry Ph.D. Program, Florida International University, Miami, Florida, USA
| | - Yanhao Lai
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA
| | - Fenfei Leng
- Biochemistry Ph.D. Program, Florida International University, Miami, Florida, USA; Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA; Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA
| | - Lata Balakrishnan
- Department of Biology, Indiana Purdue University Indianapolis, Indianapolis, Indiana, USA
| | | | - Yuan Liu
- Biochemistry Ph.D. Program, Florida International University, Miami, Florida, USA; Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, USA; Biomolecular Sciences Institute, Florida International University, Miami, Florida, USA.
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42
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Brannvoll A, Xue X, Kwon Y, Kompocholi S, Simonsen AKW, Viswalingam KS, Gonzalez L, Hickson ID, Oestergaard VH, Mankouri HW, Sung P, Lisby M. The ZGRF1 Helicase Promotes Recombinational Repair of Replication-Blocking DNA Damage in Human Cells. Cell Rep 2020; 32:107849. [PMID: 32640219 PMCID: PMC7473174 DOI: 10.1016/j.celrep.2020.107849] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/10/2020] [Accepted: 06/11/2020] [Indexed: 01/05/2023] Open
Abstract
Replication-blocking DNA lesions are particularly toxic to proliferating cells because they can lead to chromosome mis-segregation if not repaired prior to mitosis. In this study, we report that ZGRF1 null cells accumulate chromosome aberrations following replication perturbation and show sensitivity to two potent replication-blocking anticancer drugs: mitomycin C and camptothecin. Moreover, ZGRF1 null cells are defective in catalyzing DNA damage-induced sister chromatid exchange despite accumulating excessive FANCD2, RAD51, and γ-H2AX foci upon induction of interstrand DNA crosslinks. Consistent with a direct role in promoting recombinational DNA repair, we show that ZGRF1 is a 5'-to-3' helicase that catalyzes D-loop dissociation and Holliday junction branch migration. Moreover, ZGRF1 physically interacts with RAD51 and stimulates strand exchange catalyzed by RAD51-RAD54. On the basis of these data, we propose that ZGRF1 promotes repair of replication-blocking DNA lesions through stimulation of homologous recombination.
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Affiliation(s)
- André Brannvoll
- Department of Biology, University of Copenhagen, 2200 Copenhagen N, Denmark; Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Xiaoyu Xue
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | | | | | | | - Leticia Gonzalez
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Ian D Hickson
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Vibe H Oestergaard
- Department of Biology, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Hocine W Mankouri
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Michael Lisby
- Department of Biology, University of Copenhagen, 2200 Copenhagen N, Denmark; Center for Chromosome Stability, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark.
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43
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Kim KH, Hong EP, Shin JW, Chao MJ, Loupe J, Gillis T, Mysore JS, Holmans P, Jones L, Orth M, Monckton DG, Long JD, Kwak S, Lee R, Gusella JF, MacDonald ME, Lee JM. Genetic and Functional Analyses Point to FAN1 as the Source of Multiple Huntington Disease Modifier Effects. Am J Hum Genet 2020; 107:96-110. [PMID: 32589923 DOI: 10.1016/j.ajhg.2020.05.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/18/2020] [Indexed: 01/04/2023] Open
Abstract
A recent genome-wide association study of Huntington disease (HD) implicated genes involved in DNA maintenance processes as modifiers of onset, including multiple genome-wide significant signals in a chr15 region containing the DNA repair gene Fanconi-Associated Nuclease 1 (FAN1). Here, we have carried out detailed genetic, molecular, and cellular investigation of the modifiers at this locus. We find that missense changes within or near the DNA-binding domain (p.Arg507His and p.Arg377Trp) reduce FAN1's DNA-binding activity and its capacity to rescue mitomycin C-induced cytotoxicity, accounting for two infrequent onset-hastening modifier signals. We also idenified a third onset-hastening modifier signal whose mechanism of action remains uncertain but does not involve an amino acid change in FAN1. We present additional evidence that a frequent onset-delaying modifier signal does not alter FAN1 coding sequence but is associated with increased FAN1 mRNA expression in the cerebral cortex. Consistent with these findings and other cellular overexpression and/or suppression studies, knockout of FAN1 increased CAG repeat expansion in HD-induced pluripotent stem cells. Together, these studies support the process of somatic CAG repeat expansion as a therapeutic target in HD, and they clearly indicate that multiple genetic variations act by different means through FAN1 to influence HD onset in a manner that is largely additive, except in the rare circumstance that two onset-hastening alleles are present. Thus, an individual's particular combination of FAN1 haplotypes may influence their suitability for HD clinical trials, particularly if the therapeutic agent aims to reduce CAG repeat instability.
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44
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The FANC/BRCA Pathway Releases Replication Blockades by Eliminating DNA Interstrand Cross-Links. Genes (Basel) 2020; 11:genes11050585. [PMID: 32466131 PMCID: PMC7288313 DOI: 10.3390/genes11050585] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/14/2020] [Accepted: 05/21/2020] [Indexed: 12/24/2022] Open
Abstract
DNA interstrand cross-links (ICLs) represent a major barrier blocking DNA replication fork progression. ICL accumulation results in growth arrest and cell death—particularly in cell populations undergoing high replicative activity, such as cancer and leukemic cells. For this reason, agents able to induce DNA ICLs are widely used as chemotherapeutic drugs. However, ICLs are also generated in cells as byproducts of normal metabolic activities. Therefore, every cell must be capable of rescuing lCL-stalled replication forks while maintaining the genetic stability of the daughter cells in order to survive, replicate DNA and segregate chromosomes at mitosis. Inactivation of the Fanconi anemia/breast cancer-associated (FANC/BRCA) pathway by inherited mutations leads to Fanconi anemia (FA), a rare developmental, cancer-predisposing and chromosome-fragility syndrome. FANC/BRCA is the key hub for a complex and wide network of proteins that—upon rescuing ICL-stalled DNA replication forks—allows cell survival. Understanding how cells cope with ICLs is mandatory to ameliorate ICL-based anticancer therapies and provide the molecular basis to prevent or bypass cancer drug resistance. Here, we review our state-of-the-art understanding of the mechanisms involved in ICL resolution during DNA synthesis, with a major focus on how the FANC/BRCA pathway ensures DNA strand opening and prevents genomic instability.
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45
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Liu W, Palovcak A, Li F, Zafar A, Yuan F, Zhang Y. Fanconi anemia pathway as a prospective target for cancer intervention. Cell Biosci 2020; 10:39. [PMID: 32190289 PMCID: PMC7075017 DOI: 10.1186/s13578-020-00401-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/06/2020] [Indexed: 12/13/2022] Open
Abstract
Fanconi anemia (FA) is a recessive genetic disorder caused by biallelic mutations in at least one of 22 FA genes. Beyond its pathological presentation of bone marrow failure and congenital abnormalities, FA is associated with chromosomal abnormality and genomic instability, and thus represents a genetic vulnerability for cancer predisposition. The cancer relevance of the FA pathway is further established with the pervasive occurrence of FA gene alterations in somatic cancers and observations of FA pathway activation-associated chemotherapy resistance. In this article we describe the role of the FA pathway in canonical interstrand crosslink (ICL) repair and possible contributions of FA gene alterations to cancer development. We also discuss the perspectives and potential of targeting the FA pathway for cancer intervention.
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Affiliation(s)
- Wenjun Liu
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Anna Palovcak
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Fang Li
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Alyan Zafar
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Fenghua Yuan
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
| | - Yanbin Zhang
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Gautier Building Room 311, 1011 NW 15th Street, Miami, FL 33136 USA
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136 USA
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46
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Tan W, van Twest S, Leis A, Bythell-Douglas R, Murphy VJ, Sharp M, Parker MW, Crismani W, Deans AJ. Monoubiquitination by the human Fanconi anemia core complex clamps FANCI:FANCD2 on DNA in filamentous arrays. eLife 2020; 9:e54128. [PMID: 32167469 PMCID: PMC7156235 DOI: 10.7554/elife.54128] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/12/2020] [Indexed: 12/24/2022] Open
Abstract
FANCI:FANCD2 monoubiquitination is a critical event for replication fork stabilization by the Fanconi anemia (FA) DNA repair pathway. It has been proposed that at stalled replication forks, monoubiquitinated-FANCD2 serves to recruit DNA repair proteins that contain ubiquitin-binding motifs. Here, we have reconstituted the FA pathway in vitro to study functional consequences of FANCI:FANCD2 monoubiquitination. We report that monoubiquitination does not promote any specific exogenous protein:protein interactions, but instead stabilizes FANCI:FANCD2 heterodimers on dsDNA. This clamping requires monoubiquitination of only the FANCD2 subunit. We further show using electron microscopy that purified monoubiquitinated FANCI:FANCD2 forms filament-like arrays on long dsDNA. Our results reveal how monoubiquitinated FANCI:FANCD2, defective in many cancer types and all cases of FA, is activated upon DNA binding.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
- Department of Medicine (St. Vincent’s Health), The University of MelbourneMelbourneAustralia
| | - Sylvie van Twest
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Andrew Leis
- Bio21 Institute, University of MelbourneParkvilleAustralia
| | | | - Vincent J Murphy
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Michael Sharp
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Michael W Parker
- Bio21 Institute, University of MelbourneParkvilleAustralia
- Structural Biology Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
| | - Wayne Crismani
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
- Department of Medicine (St. Vincent’s Health), The University of MelbourneMelbourneAustralia
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent’s Institute of Medical ResearchFitzroyAustralia
- Department of Medicine (St. Vincent’s Health), The University of MelbourneMelbourneAustralia
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47
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Alcón P, Shakeel S, Chen ZA, Rappsilber J, Patel KJ, Passmore LA. FANCD2-FANCI is a clamp stabilized on DNA by monoubiquitination of FANCD2 during DNA repair. Nat Struct Mol Biol 2020; 27:240-248. [PMID: 32066963 PMCID: PMC7067600 DOI: 10.1038/s41594-020-0380-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/14/2020] [Indexed: 01/18/2023]
Abstract
Vertebrate DNA crosslink repair excises toxic replication-blocking DNA crosslinks. Numerous factors involved in crosslink repair have been identified, and mutations in their corresponding genes cause Fanconi anemia (FA). A key step in crosslink repair is monoubiquitination of the FANCD2-FANCI heterodimer, which then recruits nucleases to remove the DNA lesion. Here, we use cryo-EM to determine the structures of recombinant chicken FANCD2 and FANCI complexes. FANCD2-FANCI adopts a closed conformation when the FANCD2 subunit is monoubiquitinated, creating a channel that encloses double-stranded DNA (dsDNA). Ubiquitin is positioned at the interface of FANCD2 and FANCI, where it acts as a covalent molecular pin to trap the complex on DNA. In contrast, isolated FANCD2 is a homodimer that is unable to bind DNA, suggestive of an autoinhibitory mechanism that prevents premature activation. Together, our work suggests that FANCD2-FANCI is a clamp that is locked onto DNA by ubiquitin, with distinct interfaces that may recruit other DNA repair factors.
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Affiliation(s)
- Pablo Alcón
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | - Zhuo A Chen
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Juri Rappsilber
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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48
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Taylor SJ, Arends MJ, Langdon SP. Inhibitors of the Fanconi anaemia pathway as potential antitumour agents for ovarian cancer. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2020; 1:26-52. [PMID: 36046263 PMCID: PMC9400734 DOI: 10.37349/etat.2020.00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/18/2019] [Indexed: 11/30/2022] Open
Abstract
The Fanconi anaemia (FA) pathway is an important mechanism for cellular DNA damage repair, which functions to remove toxic DNA interstrand crosslinks. This is particularly relevant in the context of ovarian and other cancers which rely extensively on interstrand cross-link generating platinum chemotherapy as standard of care treatment. These cancers often respond well to initial treatment, but reoccur with resistant disease and upregulation of DNA damage repair pathways. The FA pathway is therefore of great interest as a target for therapies that aim to improve the efficacy of platinum chemotherapies, and reverse tumour resistance to these. In this review, we discuss recent advances in understanding the mechanism of interstrand cross-link repair by the FA pathway, and the potential of the component parts as targets for therapeutic agents. We then focus on the current state of play of inhibitor development, covering both the characterisation of broad spectrum inhibitors and high throughput screening approaches to identify novel small molecule inhibitors. We also consider synthetic lethality between the FA pathway and other DNA damage repair pathways as a therapeutic approach.
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Affiliation(s)
- Sarah J Taylor
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - Mark J Arends
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - Simon P Langdon
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
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49
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Rikitake M, Fujikane R, Obayashi Y, Oka K, Ozaki M, Hidaka M. MLH1-mediated recruitment of FAN1 to chromatin for the induction of apoptosis triggered by O 6 -methylguanine. Genes Cells 2020; 25:175-186. [PMID: 31955481 DOI: 10.1111/gtc.12748] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 01/03/2023]
Abstract
O6 -Methylguanines (O6 -meG), which are produced in DNA by the action of alkylating agents, are mutagenic and cytotoxic, and induce apoptosis in a mismatch repair (MMR) protein-dependent manner. To understand the molecular mechanism of O6 -meG-induced apoptosis, we performed functional analyses of FANCD2 and FANCI-associated nuclease 1 (FAN1), which was identified as an interacting partner of MLH1. Immunoprecipitation analyses showed that FAN1 interacted with both MLH1 and MSH2 after treatment with N-methyl-N-nitrosourea (MNU), indicating the formation of a FAN1-MMR complex. In comparison with control cells, FAN1-knockdown cells were more resistant to MNU, and the appearances of a sub-G1 population and caspase-9 activation were suppressed. FAN1 formed nuclear foci in an MLH1-dependent manner after MNU treatment, and some were colocalized with both MLH1 foci and single-stranded DNA (ssDNA) created at damaged sites. Under the same condition, FANCD2 also formed nuclear foci, although it was dispensable for the formation of FAN1 foci and ssDNA. MNU-induced formation of ssDNA was dramatically suppressed in FAN1-knockdown cells. We therefore propose that FAN1 is loaded on chromatin through the interaction with MLH1 and produces ssDNA by its exonuclease activity, which contributes to the activation of the DNA damage response followed by the induction of apoptosis triggered by O6 -meG.
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Affiliation(s)
- Mihoko Rikitake
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan.,Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Ryosuke Fujikane
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan.,Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
| | - Yuko Obayashi
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan.,Department of Oral and Maxillofacial Surgery, Fukuoka Dental College, Fukuoka, Japan
| | - Kyoko Oka
- Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Masao Ozaki
- Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Masumi Hidaka
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan.,Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
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50
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Tan W, van Twest S, Murphy VJ, Deans AJ. ATR-Mediated FANCI Phosphorylation Regulates Both Ubiquitination and Deubiquitination of FANCD2. Front Cell Dev Biol 2020; 8:2. [PMID: 32117957 PMCID: PMC7010609 DOI: 10.3389/fcell.2020.00002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/03/2020] [Indexed: 01/02/2023] Open
Abstract
DNA interstrand crosslinks (ICLs) are a physical barrier to replication and therefore toxic to cell viability. An important mechanism for the removal of ICLs is the Fanconi Anemia DNA repair pathway, which is initiated by mono-ubiquitination of FANCD2 and its partner protein FANCI. Here, we show that maintenance of FANCD2 and FANCI proteins in a monoubiquitinated form is regulated by the ATR-kinase. Using recombinant proteins in biochemical reconstitution experiments we show that ATR directly phosphorylates FANCI on serine 556, 559, and 565 to stabilize its association with DNA and FANCD2. This increased association with DNA stimulates the conjugation of ubiquitin to both FANCI and FANCD2, but also inhibits ubiquitin deconjugation. Using phosphomimetic and phosphodead mutants of FANCI we show that S559 and S565 are particularly important for protecting the complex from the activity of the deubiquitinating enzyme USP1:UAF1. Our results reveal a major mechanism by which ATR kinase maintains the activation of the FA pathway, by promoting the accumulation of FANCD2 in the ubiquitinated form active in DNA repair.
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Affiliation(s)
- Winnie Tan
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine (St Vincent’s Hospital), The University of Melbourne, Melbourne, VIC, Australia
| | - Sylvie van Twest
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Vincent J. Murphy
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
| | - Andrew J. Deans
- Genome Stability Unit, St Vincent’s Institute of Medical Research, Fitzroy, VIC, Australia
- Department of Medicine (St Vincent’s Hospital), The University of Melbourne, Melbourne, VIC, Australia
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