1
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Pengo M, Squitieri F. Beyond CAG Repeats: The Multifaceted Role of Genetics in Huntington Disease. Genes (Basel) 2024; 15:807. [PMID: 38927742 PMCID: PMC11203031 DOI: 10.3390/genes15060807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/11/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG expansion on the huntingtin (HTT) gene and is characterized by progressive motor, cognitive, and neuropsychiatric decline. Recently, new genetic factors besides CAG repeats have been implicated in the disease pathogenesis. Most genetic modifiers are involved in DNA repair pathways and, as the cause of the loss of CAA interruption in the HTT gene, they exert their main influence through somatic expansion. However, this mechanism might not be the only driver of HD pathogenesis, and future studies are warranted in this field. The aim of the present review is to dissect the many faces of genetics in HD pathogenesis, from cis- and trans-acting genetic modifiers to RNA toxicity, mitochondrial DNA mutations, and epigenetics factors. Exploring genetic modifiers of HD onset and progression appears crucial to elucidate not only disease pathogenesis, but also to improve disease prediction and prevention, develop biomarkers of disease progression and response to therapies, and recognize new therapeutic opportunities. Since the same genetic mechanisms are also described in other repeat expansion diseases, their implications might encompass the whole spectrum of these disorders.
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Affiliation(s)
- Marta Pengo
- Department of Molecular and Translational Medicine, University of Brescia, 25121 Brescia, Italy;
| | - Ferdinando Squitieri
- Centre for Neurological Rare Diseases (CMNR), Fondazione Lega Italiana Ricerca Huntington (LIRH), 00161 Rome, Italy
- Huntington and Rare Diseases Unit, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
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2
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Nusawardhana A, Pale LM, Nicolae CM, Moldovan GL. USP1-dependent nucleolytic expansion of PRIMPOL-generated nascent DNA strand discontinuities during replication stress. Nucleic Acids Res 2024; 52:2340-2354. [PMID: 38180818 PMCID: PMC10954467 DOI: 10.1093/nar/gkad1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 01/07/2024] Open
Abstract
DNA replication stress-induced fork arrest represents a significant threat to genomic integrity. One major mechanism of replication restart involves repriming downstream of the arrested fork by PRIMPOL, leaving behind a single-stranded DNA (ssDNA) gap. Accumulation of nascent strand ssDNA gaps has emerged as a possible determinant of the cellular hypersensitivity to genotoxic agents in certain genetic backgrounds such as BRCA deficiency, but how gaps are converted into cytotoxic structures is still unclear. Here, we investigate the processing of PRIMPOL-dependent ssDNA gaps upon replication stress induced by hydroxyurea and cisplatin. We show that gaps generated in PRIMPOL-overexpressing cells are expanded in the 3'-5' direction by the MRE11 exonuclease, and in the 5'-3' direction by the EXO1 exonuclease. This bidirectional exonucleolytic gap expansion ultimately promotes their conversion into DSBs. We moreover identify the de-ubiquitinating enzyme USP1 as a critical regulator of PRIMPOL-generated ssDNA gaps. USP1 promotes gap accumulation during S-phase, and their expansion by the MRE11 and EXO1 nucleases. This activity of USP1 is linked to its role in de-ubiquitinating PCNA, suggesting that PCNA ubiquitination prevents gap accumulation during replication. Finally, we show that USP1 depletion suppresses DSB formation in PRIMPOL-overexpressing cells, highlighting an unexpected role for USP1 in promoting genomic instability under these conditions.
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Affiliation(s)
- Alexandra Nusawardhana
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Lindsey M Pale
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Claudia M Nicolae
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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3
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Chen F, Wang S, Zeng C, Tang S, Gu H, Wang Z, Li J, Feng P, Zhang Y, Wang P, Wu Y, Shen H. Silencing circSERPINE2 restrains mesenchymal stem cell senescence via the YBX3/PCNA/p21 axis. Cell Mol Life Sci 2023; 80:325. [PMID: 37831180 PMCID: PMC10575817 DOI: 10.1007/s00018-023-04975-6] [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: 05/24/2023] [Revised: 08/29/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023]
Abstract
Increasing evidence indicates that circular RNAs (circRNAs) accumulate in aging tissues and nonproliferating cells due to their high stability. However, whether upregulation of circRNA expression mediates stem cell senescence and whether circRNAs can be targeted to alleviate aging-related disorders remain unclear. Here, RNA sequencing analysis of differentially expressed circRNAs in long-term-cultured mesenchymal stem cells (MSCs) revealed that circSERPINE2 expression was significantly increased in late passages. CircSERPINE2 small interfering RNA delayed MSC senescence and rejuvenated MSCs, while circSERPINE2 overexpression had the opposite effect. RNA pulldown followed by mass spectrometry revealed an interaction between circSERPINE2 and YBX3. CircSERPINE2 increased the affinity of YBX3 for ZO-1 through the CCAUC motif, resulting in the sequestration of YBX3 in the cytoplasm, inhibiting the association of YBX3 with the PCNA promoter and eventually affecting p21 ubiquitin-mediated degradation. In addition, our results demonstrated that senescence-related downregulation of EIF4A3 gave rise to circSERPINE2. In vivo, intra-articular injection of si-circSerpine2 restrained native joint-resident MSC senescence and cartilage degeneration in mice with aging-related osteoarthritis. Taken together, our findings provide strong evidence for a regulatory role for the circSERPINE2/YBX3/PCNA/p21 axis in MSC senescence and the therapeutic potential of si-circSERPINE2 in alleviating aging-associated syndromes, such as osteoarthritis.
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Affiliation(s)
- Fenglei Chen
- Department of Orthopedics, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Shan Wang
- Center for Biotherapy, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Chenying Zeng
- Center for Biotherapy, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Su'an Tang
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, People's Republic of China
| | - Huimin Gu
- Center for Biotherapy, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Ziming Wang
- Department of Orthopedics, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Jinteng Li
- Department of Orthopedics, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Pei Feng
- Center for Biotherapy, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Yunhui Zhang
- Department of Orthopedics, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China
| | - Peng Wang
- Department of Orthopedics, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China.
| | - Yanfeng Wu
- Center for Biotherapy, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China.
| | - Huiyong Shen
- Department of Orthopedics, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, 518033, People's Republic of China.
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4
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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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5
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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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6
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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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7
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Manils J, Marruecos L, Soler C. Exonucleases: Degrading DNA to Deal with Genome Damage, Cell Death, Inflammation and Cancer. Cells 2022; 11:cells11142157. [PMID: 35883600 PMCID: PMC9316158 DOI: 10.3390/cells11142157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/30/2022] [Accepted: 07/07/2022] [Indexed: 01/27/2023] Open
Abstract
Although DNA degradation might seem an unwanted event, it is essential in many cellular processes that are key to maintaining genomic stability and cell and organism homeostasis. The capacity to cut out nucleotides one at a time from the end of a DNA chain is present in enzymes called exonucleases. Exonuclease activity might come from enzymes with multiple other functions or specialized enzymes only dedicated to this function. Exonucleases are involved in central pathways of cell biology such as DNA replication, repair, and death, as well as tuning the immune response. Of note, malfunctioning of these enzymes is associated with immune disorders and cancer. In this review, we will dissect the impact of DNA degradation on the DNA damage response and its links with inflammation and cancer.
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Affiliation(s)
- Joan Manils
- Serra Húnter Programme, Immunology Unit, Department of Pathology and Experimental Therapy, School of Medicine, Universitat de Barcelona, Feixa Llarga s/n, 08907 L’Hospitalet de Llobregat, Spain;
- Immunity, Inflammation and Cancer Group, Oncobell Program, Institut d’Investigació Biomèdica de Bellvitge—IDIBELL, 08907 L’Hospitalet de Llobregat, Spain
| | - Laura Marruecos
- Breast Cancer Laboratory, Cancer Biology and Stem Cells Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia;
| | - Concepció Soler
- Immunity, Inflammation and Cancer Group, Oncobell Program, Institut d’Investigació Biomèdica de Bellvitge—IDIBELL, 08907 L’Hospitalet de Llobregat, Spain
- Immunology Unit, Department of Pathology and Experimental Therapy, School of Medicine, Universitat de Barcelona, 08007 Barcelona, Spain
- Correspondence:
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8
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Wu HY, Zheng Y, Laciak AR, Huang NN, Koszelak-Rosenblum M, Flint AJ, Carr G, Zhu G. Structure and Function of SNM1 Family Nucleases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1414:1-26. [PMID: 35708844 DOI: 10.1007/5584_2022_724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Three human nucleases, SNM1A, SNM1B/Apollo, and SNM1C/Artemis, belong to the SNM1 gene family. These nucleases are involved in various cellular functions, including homologous recombination, nonhomologous end-joining, cell cycle regulation, and telomere maintenance. These three proteins share a similar catalytic domain, which is characterized as a fused metallo-β-lactamase and a CPSF-Artemis-SNM1-PSO2 domain. SNM1A and SNM1B/Apollo are exonucleases, whereas SNM1C/Artemis is an endonuclease. This review contains a summary of recent research on SNM1's cellular and biochemical functions, as well as structural biology studies. In addition, protein structure prediction by the artificial intelligence program AlphaFold provides a different view of the proteins' non-catalytic domain features, which may be used in combination with current results from X-ray crystallography and cryo-EM to understand their mechanism more clearly.
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9
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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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10
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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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11
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Mancini M, Magnani E, Macchi F, Bonapace IM. The multi-functionality of UHRF1: epigenome maintenance and preservation of genome integrity. Nucleic Acids Res 2021; 49:6053-6068. [PMID: 33939809 PMCID: PMC8216287 DOI: 10.1093/nar/gkab293] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 04/02/2021] [Accepted: 04/12/2021] [Indexed: 12/23/2022] Open
Abstract
During S phase, the cooperation between the macromolecular complexes regulating DNA synthesis, epigenetic information maintenance and DNA repair is advantageous for cells, as they can rapidly detect DNA damage and initiate the DNA damage response (DDR). UHRF1 is a fundamental epigenetic regulator; its ability to coordinate DNA methylation and histone code is unique across proteomes of different species. Recently, UHRF1’s role in DNA damage repair has been explored and recognized to be as important as its role in maintaining the epigenome. UHRF1 is a sensor for interstrand crosslinks and a determinant for the switch towards homologous recombination in the repair of double-strand breaks; its loss results in enhanced sensitivity to DNA damage. These functions are finely regulated by specific post-translational modifications and are mediated by the SRA domain, which binds to damaged DNA, and the RING domain. Here, we review recent studies on the role of UHRF1 in DDR focusing on how it recognizes DNA damage and cooperates with other proteins in its repair. We then discuss how UHRF1’s epigenetic abilities in reading and writing histone modifications, or its interactions with ncRNAs, could interlace with its role in DDR.
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Affiliation(s)
- Monica Mancini
- Department of Biotechnology and Life Sciences, University of Insubria, Busto Arsizio, VA 21052, Italy
| | - Elena Magnani
- Program in Biology, New York University Abu Dhabi, Abu Dhabi, PO Box 129188, United Arab Emirates
| | - Filippo Macchi
- Program in Biology, New York University Abu Dhabi, Abu Dhabi, PO Box 129188, United Arab Emirates
| | - Ian Marc Bonapace
- Department of Biotechnology and Life Sciences, University of Insubria, Busto Arsizio, VA 21052, Italy
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12
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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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13
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Li Q, Dudás K, Tick G, Haracska L. Coordinated Cut and Bypass: Replication of Interstrand Crosslink-Containing DNA. Front Cell Dev Biol 2021; 9:699966. [PMID: 34262911 PMCID: PMC8275186 DOI: 10.3389/fcell.2021.699966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 06/07/2021] [Indexed: 12/28/2022] Open
Abstract
DNA interstrand crosslinks (ICLs) are covalently bound DNA lesions, which are commonly induced by chemotherapeutic drugs, such as cisplatin and mitomycin C or endogenous byproducts of metabolic processes. This type of DNA lesion can block ongoing RNA transcription and DNA replication and thus cause genome instability and cancer. Several cellular defense mechanism, such as the Fanconi anemia pathway have developed to ensure accurate repair and DNA replication when ICLs are present. Various structure-specific nucleases and translesion synthesis (TLS) polymerases have come into focus in relation to ICL bypass. Current models propose that a structure-specific nuclease incision is needed to unhook the ICL from the replication fork, followed by the activity of a low-fidelity TLS polymerase enabling replication through the unhooked ICL adduct. This review focuses on how, in parallel with the Fanconi anemia pathway, PCNA interactions and ICL-induced PCNA ubiquitylation regulate the recruitment, substrate specificity, activity, and coordinated action of certain nucleases and TLS polymerases in the execution of stalled replication fork rescue via ICL bypass.
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Affiliation(s)
- Qiuzhen Li
- HCEMM-BRC Mutagenesis and Carcinogenesis Research Group, Institute of Genetics, Biological Research Centre, Szeged, Hungary
| | - Kata Dudás
- HCEMM-BRC Mutagenesis and Carcinogenesis Research Group, Institute of Genetics, Biological Research Centre, Szeged, Hungary
| | - Gabriella Tick
- Mutagenesis and Carcinogenesis Research Group, Institute of Genetics, Biological Research Centre, Szeged, Hungary
| | - Lajos Haracska
- HCEMM-BRC Mutagenesis and Carcinogenesis Research Group, Institute of Genetics, Biological Research Centre, Szeged, Hungary
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14
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Siraj A, Lim DY, Tayara H, Chong KT. UbiComb: A Hybrid Deep Learning Model for Predicting Plant-Specific Protein Ubiquitylation Sites. Genes (Basel) 2021; 12:genes12050717. [PMID: 34064731 PMCID: PMC8151217 DOI: 10.3390/genes12050717] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 12/11/2022] Open
Abstract
Protein ubiquitylation is an essential post-translational modification process that performs a critical role in a wide range of biological functions, even a degenerative role in certain diseases, and is consequently used as a promising target for the treatment of various diseases. Owing to the significant role of protein ubiquitylation, these sites can be identified by enzymatic approaches, mass spectrometry analysis, and combinations of multidimensional liquid chromatography and tandem mass spectrometry. However, these large-scale experimental screening techniques are time consuming, expensive, and laborious. To overcome the drawbacks of experimental methods, machine learning and deep learning-based predictors were considered for prediction in a timely and cost-effective manner. In the literature, several computational predictors have been published across species; however, predictors are species-specific because of the unclear patterns in different species. In this study, we proposed a novel approach for predicting plant ubiquitylation sites using a hybrid deep learning model by utilizing convolutional neural network and long short-term memory. The proposed method uses the actual protein sequence and physicochemical properties as inputs to the model and provides more robust predictions. The proposed predictor achieved the best result with accuracy values of 80% and 81% and F-scores of 79% and 82% on the 10-fold cross-validation and an independent dataset, respectively. Moreover, we also compared the testing of the independent dataset with popular ubiquitylation predictors; the results demonstrate that our model significantly outperforms the other methods in prediction classification results.
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Affiliation(s)
- Arslan Siraj
- Department of Electronics and Information Engineering, Jeonbuk National University, Jeonju 54896, Korea; (A.S.); (D.Y.L.)
| | - Dae Yeong Lim
- Department of Electronics and Information Engineering, Jeonbuk National University, Jeonju 54896, Korea; (A.S.); (D.Y.L.)
| | - Hilal Tayara
- School of International Engineering and Science, Jeonbuk National University, Jeonju 54896, Korea
- Correspondence: (H.T.); (K.T.C.)
| | - Kil To Chong
- Department of Electronics and Information Engineering, Jeonbuk National University, Jeonju 54896, Korea; (A.S.); (D.Y.L.)
- Advanced Electronics and Information Research Center, Jeonbuk National University, Jeonju 54896, Korea
- Correspondence: (H.T.); (K.T.C.)
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15
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Buzon B, Grainger RA, Rzadki C, Huang SYM, Junop M. Identification of Bioactive SNM1A Inhibitors. ACS OMEGA 2021; 6:9352-9361. [PMID: 33869915 PMCID: PMC8047731 DOI: 10.1021/acsomega.0c03528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
SNM1A is a nuclease required to repair DNA interstrand cross-links (ICLs) caused by some anticancer compounds, including cisplatin. Unlike other nucleases involved in ICL repair, SNM1A is not needed to restore other forms of DNA damage. As such, SNM1A is an attractive target for selectively increasing the efficacy of ICL-based chemotherapy. Using a fluorescence-based exonuclease assay, we screened a bioactive library of compounds for inhibition of SNM1A. Of the 52 compounds initially identified as hits, 22 compounds showed dose-response inhibition of SNM1A. An orthogonal gel-based assay further confirmed nine small molecules as SNM1A nuclease activity inhibitors with IC50 values in the mid-nanomolar to low micromolar range. Finally, three compounds showed no toxicity at concentrations able to significantly potentiate the cytotoxicity of cisplatin. These compounds represent potential leads for further optimization to sensitize cells toward chemotherapeutic agents inducing ICL damage.
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Affiliation(s)
- Beverlee Buzon
- Department
of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
- Department
of Biochemistry, Western University, London, Ontario N6A 5C1, Canada
| | - Ryan A. Grainger
- Department
of Biochemistry, Western University, London, Ontario N6A 5C1, Canada
| | - Cameron Rzadki
- Department
of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Simon York Ming Huang
- Department
of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Murray Junop
- Department
of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
- Department
of Biochemistry, Western University, London, Ontario N6A 5C1, Canada
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16
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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] [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
| | - Alessandro A Sartori
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - 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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17
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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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18
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PCAF-Mediated Histone Acetylation Promotes Replication Fork Degradation by MRE11 and EXO1 in BRCA-Deficient Cells. Mol Cell 2020; 80:327-344.e8. [PMID: 32966758 DOI: 10.1016/j.molcel.2020.08.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 07/22/2020] [Accepted: 08/26/2020] [Indexed: 12/12/2022]
Abstract
Stabilization of stalled replication forks is a prominent mechanism of PARP (Poly(ADP-ribose) Polymerase) inhibitor (PARPi) resistance in BRCA-deficient tumors. Epigenetic mechanisms of replication fork stability are emerging but remain poorly understood. Here, we report the histone acetyltransferase PCAF (p300/CBP-associated) as a fork-associated protein that promotes fork degradation in BRCA-deficient cells by acetylating H4K8 at stalled replication forks, which recruits MRE11 and EXO1. A H4K8ac binding domain within MRE11/EXO1 is required for their recruitment to stalled forks. Low PCAF levels, which we identify in a subset of BRCA2-deficient tumors, stabilize stalled forks, resulting in PARPi resistance in BRCA-deficient cells. Furthermore, PCAF activity is tightly regulated by ATR (ataxia telangiectasia and Rad3-related), which phosphorylates PCAF on serine 264 (S264) to limit its association and activity at stalled forks. Our results reveal PCAF and histone acetylation as critical regulators of fork stability and PARPi responses in BRCA-deficient cells, which provides key insights into targeting BRCA-deficient tumors and identifying epigenetic modulators of chemotherapeutic responses.
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19
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Chen DB, Xie XW, Zhao YJ, Wang XY, Liao WJ, Chen P, Deng KJ, Fei R, Qin WY, Wang JH, Wu X, Shao QX, Wei L, Chen HS. RFX5 promotes the progression of hepatocellular carcinoma through transcriptional activation of KDM4A. Sci Rep 2020; 10:14538. [PMID: 32883983 PMCID: PMC7471945 DOI: 10.1038/s41598-020-71403-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/14/2020] [Indexed: 02/07/2023] Open
Abstract
Regulatory factor X-5 (RFX5) represents a key transcription regulator of MHCII gene expression in the immune system. This study aims to explore the molecular mechanisms and biological significance of RFX5. Firstly, by analyzing ENCODE chromatin immunoprecipitation (ChIP)-seq in HepG2 and TCGA RNA-seq data, we discovered lysine-specific demethylase 4A (KDM4A), also named JMJD2A, to be a major downstream target gene of RFX5. Moreover, RFX5 was verified to bind directly to the KDM4A's promoter region and sequentially promoted its transcription determined by the ChIP-PCR assay and luciferase assay. In addition, RFX5-dependent regulation of KDM4A was demonstrated in HCC. Compared with adjacent non-tumor tissues, the expression levels of KDM4A were significantly raised in HCC tumor tissues. Notably, elevated levels of KDM4A were strongly correlated with HCC patient prognosis. Functionally, KDM4A overexpression largely rescued the growth inhibitory effects of RFX5 deletion, highlighting KDM4A as a downstream effector of RFX5. Mechanistically, the RFX5-KDM4A pathway promoted the progression of the cell cycle from G0/G1 to S phase and was protective against cell apoptosis through regulation of p53 and its downstream genes in HCC. In conclusion, RFX5 could promote HCC progression via transcriptionally activating KDM4A expression.
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Affiliation(s)
- Dong-Bo Chen
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China
| | - Xing-Wang Xie
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China
| | - Yang-Jing Zhao
- Department of Immunology, and the Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Xue-Yan Wang
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China
| | - Wei-Jia Liao
- Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Pu Chen
- Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Kang-Jian Deng
- Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Ran Fei
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China
| | - Wan-Ying Qin
- Laboratory of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Jiang-Hua Wang
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China
| | - Xu Wu
- Center of Excellence, Becton Dickinson Biosciences, China Central Place, Beijing, 100176, China
| | - Qi-Xiang Shao
- Department of Immunology, and the Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Lai Wei
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China
| | - Hong-Song Chen
- Peking University People's Hospital, Peking University Hepatology Institute, Beijing Key Laboratory of Hepatitis C and Immunotherapy for Liver Disease, Beijing, 100044, China.
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20
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Tabrizi SJ, Flower MD, Ross CA, Wild EJ. Huntington disease: new insights into molecular pathogenesis and therapeutic opportunities. Nat Rev Neurol 2020; 16:529-546. [PMID: 32796930 DOI: 10.1038/s41582-020-0389-4] [Citation(s) in RCA: 216] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2020] [Indexed: 12/11/2022]
Abstract
Huntington disease (HD) is a neurodegenerative disease caused by CAG repeat expansion in the huntingtin gene (HTT) and involves a complex web of pathogenic mechanisms. Mutant HTT (mHTT) disrupts transcription, interferes with immune and mitochondrial function, and is aberrantly modified post-translationally. Evidence suggests that the mHTT RNA is toxic, and at the DNA level, somatic CAG repeat expansion in vulnerable cells influences the disease course. Genome-wide association studies have identified DNA repair pathways as modifiers of somatic instability and disease course in HD and other repeat expansion diseases. In animal models of HD, nucleocytoplasmic transport is disrupted and its restoration is neuroprotective. Novel cerebrospinal fluid (CSF) and plasma biomarkers are among the earliest detectable changes in individuals with premanifest HD and have the sensitivity to detect therapeutic benefit. Therapeutically, the first human trial of an HTT-lowering antisense oligonucleotide successfully, and safely, reduced the CSF concentration of mHTT in individuals with HD. A larger trial, powered to detect clinical efficacy, is underway, along with trials of other HTT-lowering approaches. In this Review, we discuss new insights into the molecular pathogenesis of HD and future therapeutic strategies, including the modulation of DNA repair and targeting the DNA mutation itself.
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Affiliation(s)
- Sarah J Tabrizi
- Huntington's Disease Centre, University College London, London, UK. .,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK. .,UK Dementia Research Institute, University College London, London, UK.
| | - Michael D Flower
- Huntington's Disease Centre, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
| | - Christopher A Ross
- Departments of Neurology, Neuroscience and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Edward J Wild
- Huntington's Disease Centre, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK
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21
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Ma X, Tang TS, Guo C. Regulation of translesion DNA synthesis in mammalian cells. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:680-692. [PMID: 31983077 DOI: 10.1002/em.22359] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/29/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The genomes of all living cells are under endogenous and exogenous attacks every day, causing diverse genomic lesions. Most of the lesions can be timely repaired by multiple DNA repair pathways. However, some may persist during S-phase, block DNA replication, and challenge genome integrity. Eukaryotic cells have evolved DNA damage tolerance (DDT) to mitigate the lethal effects of arrested DNA replication without prior removal of the offending DNA damage. As one important mode of DDT, translesion DNA synthesis (TLS) utilizes multiple low-fidelity DNA polymerases to incorporate nucleotides opposite DNA lesions to maintain genome integrity. Three different mechanisms have been proposed to regulate the polymerase switching between high-fidelity DNA polymerases in the replicative machinery and one or more specialized enzymes. Additionally, it is known that proliferating cell nuclear antigen (PCNA) mono-ubiquitination is essential for optimal TLS. Given its error-prone property, TLS is closely associated with spontaneous and drug-induced mutations in cells, which can potentially lead to tumorigenesis and chemotherapy resistance. Therefore, TLS process must be tightly modulated to avoid unwanted mutagenesis. In this review, we will focus on polymerase switching and PCNA mono-ubiquitination, the two key events in TLS pathway in mammalian cells, and summarize current understandings of regulation of TLS process at the levels of protein-protein interactions, post-translational modifications as well as transcription and noncoding RNAs. Environ. Mol. Mutagen. 61:680-692, 2020. © 2020 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaolu Ma
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Caixia Guo
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
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22
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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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23
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Pilzecker B, Buoninfante OA, Jacobs H. DNA damage tolerance in stem cells, ageing, mutagenesis, disease and cancer therapy. Nucleic Acids Res 2019; 47:7163-7181. [PMID: 31251805 PMCID: PMC6698745 DOI: 10.1093/nar/gkz531] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 05/22/2019] [Accepted: 06/26/2019] [Indexed: 12/12/2022] Open
Abstract
The DNA damage response network guards the stability of the genome from a plethora of exogenous and endogenous insults. An essential feature of the DNA damage response network is its capacity to tolerate DNA damage and structural impediments during DNA synthesis. This capacity, referred to as DNA damage tolerance (DDT), contributes to replication fork progression and stability in the presence of blocking structures or DNA lesions. Defective DDT can lead to a prolonged fork arrest and eventually cumulate in a fork collapse that involves the formation of DNA double strand breaks. Four principal modes of DDT have been distinguished: translesion synthesis, fork reversal, template switching and repriming. All DDT modes warrant continuation of replication through bypassing the fork stalling impediment or repriming downstream of the impediment in combination with filling of the single-stranded DNA gaps. In this way, DDT prevents secondary DNA damage and critically contributes to genome stability and cellular fitness. DDT plays a key role in mutagenesis, stem cell maintenance, ageing and the prevention of cancer. This review provides an overview of the role of DDT in these aspects.
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Affiliation(s)
- Bas Pilzecker
- Division of Tumor Biology and Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Olimpia Alessandra Buoninfante
- Division of Tumor Biology and Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Heinz Jacobs
- Division of Tumor Biology and Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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24
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Buzon B, Grainger R, Huang S, Rzadki C, Junop MS. Structure-specific endonuclease activity of SNM1A enables processing of a DNA interstrand crosslink. Nucleic Acids Res 2019; 46:9057-9066. [PMID: 30165656 PMCID: PMC6158701 DOI: 10.1093/nar/gky759] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/20/2018] [Indexed: 01/09/2023] Open
Abstract
DNA interstrand crosslinks (ICLs) covalently join opposing strands, blocking both replication and transcription, therefore making ICL-inducing compounds highly toxic and ideal anti-cancer agents. While incisions surrounding the ICL are required to remove damaged DNA, it is currently unclear which endonucleases are needed for this key event. SNM1A has been shown to play an important function in human ICL repair, however its suggested role has been limited to exonuclease activity and not strand incision. Here we show that SNM1A has endonuclease activity, having the ability to cleave DNA structures that arise during the initiation of ICL repair. In particular, this endonuclease activity cleaves single-stranded DNA. Given that unpaired DNA regions occur 5′ to an ICL, these findings suggest SNM1A may act as either an endonuclease and/or exonuclease during ICL repair. This finding is significant as it expands the potential role of SNM1A in ICL repair.
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Affiliation(s)
- Beverlee Buzon
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster, University, Hamilton, Ontario L8N 3Z5, Canada.,Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Ryan Grainger
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, Ontario N6A 5C1, Canada
| | - Simon Huang
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster, University, Hamilton, Ontario L8N 3Z5, Canada
| | - Cameron Rzadki
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster, University, Hamilton, Ontario L8N 3Z5, Canada
| | - Murray S Junop
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster, University, Hamilton, Ontario L8N 3Z5, Canada.,Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, Ontario N6A 5C1, Canada
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25
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Goold R, Flower M, Moss DH, Medway C, Wood-Kaczmar A, Andre R, Farshim P, Bates GP, Holmans P, Jones L, Tabrizi SJ. FAN1 modifies Huntington's disease progression by stabilizing the expanded HTT CAG repeat. Hum Mol Genet 2019; 28:650-661. [PMID: 30358836 PMCID: PMC6360275 DOI: 10.1093/hmg/ddy375] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 11/13/2022] Open
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disease caused by an expanded CAG repeat in the huntingtin (HTT) gene. CAG repeat length explains around half of the variation in age at onset (AAO) but genetic variation elsewhere in the genome accounts for a significant proportion of the remainder. Genome-wide association studies have identified a bidirectional signal on chromosome 15, likely underlain by FANCD2- and FANCI-associated nuclease 1 (FAN1), a nuclease involved in DNA interstrand cross link repair. Here we show that increased FAN1 expression is significantly associated with delayed AAO and slower progression of HD, suggesting FAN1 is protective in the context of an expanded HTT CAG repeat. FAN1 overexpression in human cells reduces CAG repeat expansion in exogenously expressed mutant HTT exon 1, and in patient-derived stem cells and differentiated medium spiny neurons, FAN1 knockdown increases CAG repeat expansion. The stabilizing effects are FAN1 concentration and CAG repeat length-dependent. We show that FAN1 binds to the expanded HTT CAG repeat DNA and its nuclease activity is not required for protection against CAG repeat expansion. These data shed new mechanistic insights into how the genetic modifiers of HD act to alter disease progression and show that FAN1 affects somatic expansion of the CAG repeat through a nuclease-independent mechanism. This provides new avenues for therapeutic interventions in HD and potentially other triplet repeat disorders.
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Affiliation(s)
- Robert Goold
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
| | - Michael Flower
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
| | - Davina Hensman Moss
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
| | - Chris Medway
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, CF24 4HQ, UK
| | - Alison Wood-Kaczmar
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
| | - Ralph Andre
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
| | - Pamela Farshim
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
| | - Gill P Bates
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
- UK Dementia Research Institute, University College London, WC1N 3BG, UK
| | - Peter Holmans
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, CF24 4HQ, UK
| | - Lesley Jones
- Medical Research Council Centre for Neuropsychiatric Genetics and Genomics, Cardiff University, CF24 4HQ, UK
| | - Sarah J Tabrizi
- UCL Huntington’s Disease Centre,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London,Queen Square, London WC1N 3BG, UK
- UK Dementia Research Institute, University College London, WC1N 3BG, UK
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26
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Suan Lim K, Li H, Roberts EA, Gaudiano EF, Clairmont C, Sambel L, Ponnienselvan K, Liu JC, Yang C, Kozono D, Parmar K, Yusufzai T, Zheng N, D’Andrea AD. USP1 Is Required for Replication Fork Protection in BRCA1-Deficient Tumors. Mol Cell 2018; 72:925-941.e4. [PMID: 30576655 PMCID: PMC6390489 DOI: 10.1016/j.molcel.2018.10.045] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 08/23/2018] [Accepted: 10/29/2018] [Indexed: 12/15/2022]
Abstract
BRCA1-deficient tumor cells have defects in homologous-recombination repair and replication fork stability, resulting in PARP inhibitor sensitivity. Here, we demonstrate that a deubiquitinase, USP1, is upregulated in tumors with mutations in BRCA1. Knockdown or inhibition of USP1 resulted in replication fork destabilization and decreased viability of BRCA1-deficient cells, revealing a synthetic lethal relationship. USP1 binds to and is stimulated by fork DNA. A truncated form of USP1, lacking its DNA-binding region, was not stimulated by DNA and failed to localize and protect replication forks. Persistence of monoubiquitinated PCNA at the replication fork was the mechanism of cell death in the absence of USP1. Taken together, USP1 exhibits DNA-mediated activation at the replication fork, protects the fork, and promotes survival in BRCA1-deficient cells. Inhibition of USP1 may be a useful treatment for a subset of PARP-inhibitor-resistant BRCA1-deficient tumors with acquired replication fork stabilization.
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Affiliation(s)
- Kah Suan Lim
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Heng Li
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - Emma A. Roberts
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Emily F. Gaudiano
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Connor Clairmont
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Larissa Sambel
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA,Center for DNA Damage and Repair, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | | | - Jessica C. Liu
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Chunyu Yang
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA,Center for DNA Damage and Repair, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - David Kozono
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Kalindi Parmar
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA,Center for DNA Damage and Repair, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Timur Yusufzai
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA,Howard Hughes Medical Institute, Box 357280, Seattle, WA
| | - Alan D. D’Andrea
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA,Center for DNA Damage and Repair, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
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27
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Kim SM, Forsburg SL. Regulation of Structure-Specific Endonucleases in Replication Stress. Genes (Basel) 2018; 9:genes9120634. [PMID: 30558228 PMCID: PMC6316474 DOI: 10.3390/genes9120634] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/16/2022] Open
Abstract
Replication stress results in various forms of aberrant replication intermediates that need to be resolved for faithful chromosome segregation. Structure-specific endonucleases (SSEs) recognize DNA secondary structures rather than primary sequences and play key roles during DNA repair and replication stress. Holliday junction resolvase MUS81 (methyl methane sulfonate (MMS), and UV-sensitive protein 81) and XPF (xeroderma pigmentosum group F-complementing protein) are a subset of SSEs that resolve aberrant replication structures. To ensure genome stability and prevent unnecessary DNA breakage, these SSEs are tightly regulated by the cell cycle and replication checkpoints. We discuss the regulatory network that control activities of MUS81 and XPF and briefly mention other SSEs involved in the resolution of replication intermediates.
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Affiliation(s)
- Seong Min Kim
- Program in Molecular & Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
| | - Susan L Forsburg
- Program in Molecular & Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
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28
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CtIP-Mediated Fork Protection Synergizes with BRCA1 to Suppress Genomic Instability upon DNA Replication Stress. Mol Cell 2018; 72:568-582.e6. [DOI: 10.1016/j.molcel.2018.09.014] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 06/08/2018] [Accepted: 09/12/2018] [Indexed: 12/30/2022]
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29
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Yates M, Maréchal A. Ubiquitylation at the Fork: Making and Breaking Chains to Complete DNA Replication. Int J Mol Sci 2018; 19:E2909. [PMID: 30257459 PMCID: PMC6213728 DOI: 10.3390/ijms19102909] [Citation(s) in RCA: 10] [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: 08/31/2018] [Revised: 09/20/2018] [Accepted: 09/24/2018] [Indexed: 12/11/2022] Open
Abstract
The complete and accurate replication of the genome is a crucial aspect of cell proliferation that is often perturbed during oncogenesis. Replication stress arising from a variety of obstacles to replication fork progression and processivity is an important contributor to genome destabilization. Accordingly, cells mount a complex response to this stress that allows the stabilization and restart of stalled replication forks and enables the full duplication of the genetic material. This response articulates itself on three important platforms, Replication Protein A/RPA-coated single-stranded DNA, the DNA polymerase processivity clamp PCNA and the FANCD2/I Fanconi Anemia complex. On these platforms, the recruitment, activation and release of a variety of genome maintenance factors is regulated by post-translational modifications including mono- and poly-ubiquitylation. Here, we review recent insights into the control of replication fork stability and restart by the ubiquitin system during replication stress with a particular focus on human cells. We highlight the roles of E3 ubiquitin ligases, ubiquitin readers and deubiquitylases that provide the required flexibility at stalled forks to select the optimal restart pathways and rescue genome stability during stressful conditions.
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Affiliation(s)
- Maïlyn Yates
- Department of Biology, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
| | - Alexandre Maréchal
- Department of Biology, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
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30
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Yau WY, O'Connor E, Sullivan R, Akijian L, Wood NW. DNA repair in trinucleotide repeat ataxias. FEBS J 2018; 285:3669-3682. [PMID: 30152109 DOI: 10.1111/febs.14644] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/15/2018] [Accepted: 08/23/2018] [Indexed: 12/21/2022]
Abstract
The inherited cerebellar ataxias comprise of a genetic heterogeneous group of disorders. Pathogenic expansions of cytosine-adenine-guanine (CAG) encoding polyglutamine tracts account for the largest proportion of autosomal dominant cerebellar ataxias, while GAA expansion in the first introns of frataxin gene is the commonest cause of autosomal recessive cerebellar ataxias. Currently, there is no available treatment to alter the disease trajectory, with devastating consequences for affected individuals. Inter- and Intrafamily phenotypic variability suggest the existence of genetic modifiers, which may become targets amendable to treatment. Recent studies have demonstrated the importance of DNA repair pathways in modifying spinocerebellar ataxia with CAG repeat expansions. In this review, we discuss the mechanisms in which DNA repair pathways, epigenetics and other genetic factors may act as modifiers in cerebellar ataxias due to trinucleotide repeat expansions.
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Affiliation(s)
- Wai Yan Yau
- Department of Molecular Neuroscience, Institute of Neurology, University College London, UK
| | - Emer O'Connor
- Department of Molecular Neuroscience, Institute of Neurology, University College London, UK
| | - Roisin Sullivan
- Department of Molecular Neuroscience, Institute of Neurology, University College London, UK
| | - Layan Akijian
- Department of Neurology, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Nicholas W Wood
- Department of Molecular Neuroscience, Institute of Neurology, University College London, UK.,Neurogenetics laboratory, The National Hospital for Neurology and Neurosurgery, London, UK
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31
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Zhao XN, Usdin K. FAN1 protects against repeat expansions in a Fragile X mouse model. DNA Repair (Amst) 2018; 69:1-5. [PMID: 29990673 PMCID: PMC6119480 DOI: 10.1016/j.dnarep.2018.07.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/03/2018] [Accepted: 07/03/2018] [Indexed: 10/28/2022]
Abstract
The Fragile X-related disorders (FXDs) are members of a large group of human neurological or neurodevelopmental conditions known as the Repeat Expansion Diseases. The mutation responsible for all of these diseases is an expansion in the size of a disease-specific tandem repeat tract. However, the underlying cause of this unusual mutation is unknown. Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) in the vicinity of the FAN1 (MIM* 613534) gene that are associated with variations in the age at onset of a number of Repeat Expansion Diseases. FAN1 is a nuclease that has both 5'-3' exonuclease and 5' flap endonuclease activities. Here we show in a model for the FXDs that Fan1-/- mice have expansions that, in some tissues including brain, are 2-3 times as extensive as they are in Fan1+/+ mice. However, no effect of the loss of FAN1 was apparent for germ line expansions. Thus, FAN1 plays an important role in protecting against somatic expansions but is either not involved in protecting against intergenerational repeat expansions or is redundant with other related enzymes. However, since loss of FAN1 results in increased expansions in brain and other somatic tissue, FAN1 polymorphisms may be important disease modifiers in those Repeat Expansion Diseases in which somatic expansion contributes to age at onset or disease severity.
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Affiliation(s)
- Xiao-Nan Zhao
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, United States.
| | - Karen Usdin
- Section on Gene Structure and Disease, Laboratory of Cell and Molecular Biology, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, United States.
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32
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Maneuvers on PCNA Rings during DNA Replication and Repair. Genes (Basel) 2018; 9:genes9080416. [PMID: 30126151 PMCID: PMC6116012 DOI: 10.3390/genes9080416] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 08/08/2018] [Accepted: 08/09/2018] [Indexed: 12/20/2022] Open
Abstract
DNA replication and repair are essential cellular processes that ensure genome duplication and safeguard the genome from deleterious mutations. Both processes utilize an abundance of enzymatic functions that need to be tightly regulated to ensure dynamic exchange of DNA replication and repair factors. Proliferating cell nuclear antigen (PCNA) is the major coordinator of faithful and processive replication and DNA repair at replication forks. Post-translational modifications of PCNA, ubiquitination and acetylation in particular, regulate the dynamics of PCNA-protein interactions. Proliferating cell nuclear antigen (PCNA) monoubiquitination elicits ‘polymerase switching’, whereby stalled replicative polymerase is replaced with a specialized polymerase, while PCNA acetylation may reduce the processivity of replicative polymerases to promote homologous recombination-dependent repair. While regulatory functions of PCNA ubiquitination and acetylation have been well established, the regulation of PCNA-binding proteins remains underexplored. Considering the vast number of PCNA-binding proteins, many of which have similar PCNA binding affinities, the question arises as to the regulation of the strength and sequence of their binding to PCNA. Here I provide an overview of post-translational modifications on both PCNA and PCNA-interacting proteins and discuss their relevance for the regulation of the dynamic processes of DNA replication and repair.
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