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Ng RR, Lin Z, Zhang Y, Ti SC, Javed A, Wong JWH, Fang Q, Leung JWC, Tang AHN, Huen MSY. R-loop resolution by ARIP4 helicase promotes androgen-mediated transcription induction. SCIENCE ADVANCES 2024; 10:eadm9577. [PMID: 39028815 PMCID: PMC11259169 DOI: 10.1126/sciadv.adm9577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 06/14/2024] [Indexed: 07/21/2024]
Abstract
Pausing of RNA polymerase II (Pol II) at transcription start sites (TSSs) primes target genes for productive elongation. Coincidentally, DNA double-strand breaks (DSBs) enrich at highly transcribed and Pol II-paused genes, although their interplay remains undefined. Using androgen receptor (AR) signaling as a model, we have uncovered AR-interacting protein 4 (ARIP4) helicase as a driver of androgen-dependent transcription induction. Chromatin immunoprecipitation sequencing analysis revealed that ARIP4 preferentially co-occupies TSSs with paused Pol II. Moreover, we found that ARIP4 complexes with topoisomerase II beta and mediates transient DSB formation upon hormone stimulation. Accordingly, ARIP4 deficiency compromised release of paused Pol II and resulted in R-loop accumulation at a panel of highly transcribed AR target genes. Last, we showed that ARIP4 binds and unwinds R-loops in vitro and that its expression positively correlates with prostate cancer progression. We propose that androgen stimulation triggers ARIP4-mediated unwinding of R-loops at TSSs, enforcing Pol II pause release to effectively drive an androgen-dependent expression program.
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Affiliation(s)
- Raissa Regina Ng
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Zhongyang Lin
- Department of Biology, Shantou University, Shantou, Guangdong, China
| | - Yanmin Zhang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Shih Chieh Ti
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Asif Javed
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Jason Wing Hon Wong
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Qingming Fang
- Department of Biochemistry and Structural Biology and Greehey Children’s Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Justin Wai Chung Leung
- Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Alex Hin Ning Tang
- Department of Pathology, School of Clinical Medicine LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Michael Shing Yan Huen
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
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2
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Cao H, Deng B, Song T, Lian J, Xia L, Chu X, Zhang Y, Yang F, Wang C, Cai Y, Diao Y, Kapranov P. Genome-wide profiles of DNA damage represent highly accurate predictors of mammalian age. Aging Cell 2024; 23:e14122. [PMID: 38391092 PMCID: PMC11113270 DOI: 10.1111/acel.14122] [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: 10/29/2023] [Revised: 01/18/2024] [Accepted: 02/11/2024] [Indexed: 02/24/2024] Open
Abstract
The identification of novel age-related biomarkers represents an area of intense research interest. Despite multiple studies associating DNA damage with aging, there is a glaring paucity of DNA damage-based biomarkers of age, mainly due to the lack of precise methods for genome-wide surveys of different types of DNA damage. Recently, we developed two techniques for genome-wide mapping of the most prevalent types of DNA damage, single-strand breaks and abasic sites, with nucleotide-level resolution. Herein, we explored the potential of genomic patterns of DNA damage identified by these methods as a source of novel age-related biomarkers using mice as a model system. Strikingly, we found that models based on genomic patterns of either DNA lesion could accurately predict age with higher precision than the commonly used transcriptome analysis. Interestingly, the informative patterns were limited to relatively few genes and the DNA damage levels were positively or negatively correlated with age. These findings show that previously unexplored high-resolution genomic patterns of DNA damage contain useful information that can contribute significantly to both practical applications and basic science.
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Affiliation(s)
- Huifen Cao
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Bolin Deng
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Tianrong Song
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Jiabian Lian
- Department of Clinical Laboratorythe First Affiliated Hospital of Xiamen UniversityXiamenChina
| | - Lu Xia
- Xiamen Cell Therapy Research Centerthe First Affiliated Hospital of Xiamen UniversityXiamenChina
| | | | - Yufei Zhang
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Fujian Yang
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Chunlian Wang
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Ye Cai
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Yong Diao
- Institute of Genomics, School of MedicineHuaqiao UniversityXiamenChina
| | - Philipp Kapranov
- State Key Laboratory of Cellular Stress Biology, School of Life SciencesXiamen UniversityXiamenChina
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3
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Cao H, Zhang Y, Song T, Xia L, Cai Y, Kapranov P. Common occurrence of hotspots of single strand DNA breaks at transcriptional start sites. BMC Genomics 2024; 25:368. [PMID: 38622509 PMCID: PMC11017599 DOI: 10.1186/s12864-024-10284-4] [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: 12/28/2023] [Accepted: 04/03/2024] [Indexed: 04/17/2024] Open
Abstract
BACKGROUND We recently developed two high-resolution methods for genome-wide mapping of two prominent types of DNA damage, single-strand DNA breaks (SSBs) and abasic (AP) sites and found highly complex and non-random patterns of these lesions in mammalian genomes. One salient feature of SSB and AP sites was the existence of single-nucleotide hotspots for both lesions. RESULTS In this work, we show that SSB hotspots are enriched in the immediate vicinity of transcriptional start sites (TSSs) in multiple normal mammalian tissues, however the magnitude of enrichment varies significantly with tissue type and appears to be limited to a subset of genes. SSB hotspots around TSSs are enriched on the template strand and associate with higher expression of the corresponding genes. Interestingly, SSB hotspots appear to be at least in part generated by the base-excision repair (BER) pathway from the AP sites. CONCLUSIONS Our results highlight complex relationship between DNA damage and regulation of gene expression and suggest an exciting possibility that SSBs at TSSs might function as sensors of DNA damage to activate genes important for DNA damage response.
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Affiliation(s)
- Huifen Cao
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Yufei Zhang
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Tianrong Song
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Lu Xia
- Xiamen Cell Therapy Research Center, The First Affiliated Hospital of Xiamen University, 361000, Xiamen, China
| | - Ye Cai
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Philipp Kapranov
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, 361102, Xiamen, China.
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4
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Segev A, Heady L, Crewe M, Madabhushi R. Mapping catalytically engaged TOP2B in neurons reveals the principles of topoisomerase action within the genome. Cell Rep 2024; 43:113809. [PMID: 38377005 PMCID: PMC11064056 DOI: 10.1016/j.celrep.2024.113809] [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: 03/20/2023] [Revised: 12/22/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
We trapped catalytically engaged topoisomerase IIβ (TOP2B) in covalent DNA cleavage complexes (TOP2Bccs) and mapped their positions genome-wide in cultured mouse cortical neurons. We report that TOP2Bcc distribution varies with both nucleosome and compartmental chromosome organization. While TOP2Bccs in gene bodies correlate with their level of transcription, highly expressed genes that lack the usually associated chromatin marks, such as H3K36me3, show reduced TOP2Bccs, suggesting that histone posttranslational modifications regulate TOP2B activity. Promoters with high RNA polymerase II occupancy show elevated TOP2B chromatin immunoprecipitation sequencing signals but low TOP2Bccs, indicating that TOP2B catalytic engagement is curtailed at active promoters. Surprisingly, either poisoning or inhibiting TOP2B increases nascent transcription at most genes and enhancers but reduces transcription within long genes. These effects are independent of transcript length and instead correlate with the presence of intragenic enhancers. Together, these results clarify how cells modulate the catalytic engagement of topoisomerases to affect transcription.
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Affiliation(s)
- Amir Segev
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Peter O' Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lance Heady
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Peter O' Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Morgan Crewe
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Peter O' Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ram Madabhushi
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Peter O' Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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5
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Cowell IG, Casement JW, Austin CA. To Break or Not to Break: The Role of TOP2B in Transcription. Int J Mol Sci 2023; 24:14806. [PMID: 37834253 PMCID: PMC10573011 DOI: 10.3390/ijms241914806] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023] Open
Abstract
Transcription and its regulation pose challenges related to DNA torsion and supercoiling of the DNA template. RNA polymerase tracking the helical groove of the DNA introduces positive helical torsion and supercoiling upstream and negative torsion and supercoiling behind its direction of travel. This can inhibit transcriptional elongation and other processes essential to transcription. In addition, chromatin remodeling associated with gene activation can generate or be hindered by excess DNA torsional stress in gene regulatory regions. These topological challenges are solved by DNA topoisomerases via a strand-passage reaction which involves transiently breaking and re-joining of one (type I topoisomerases) or both (type II topoisomerases) strands of the phosphodiester backbone. This review will focus on one of the two mammalian type II DNA topoisomerase enzymes, DNA topoisomerase II beta (TOP2B), that have been implicated in correct execution of developmental transcriptional programs and in signal-induced transcription, including transcriptional activation by nuclear hormone ligands. Surprisingly, several lines of evidence indicate that TOP2B-mediated protein-free DNA double-strand breaks are involved in signal-induced transcription. We discuss the possible significance and origins of these DSBs along with a network of protein interaction data supporting a variety of roles for TOP2B in transcriptional regulation.
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Affiliation(s)
- Ian G. Cowell
- Biosciences Institute, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - John W. Casement
- Bioinformatics Support Unit, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Caroline A. Austin
- Biosciences Institute, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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6
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Tan A, Younis AZ, Evans A, Creighton JV, Coveny C, Boocock DJ, Sale C, Lavery GG, Coutts AS, Doig CL. PARP1 mediated PARylation contributes to myogenic progression and glucocorticoid transcriptional response. Cell Death Discov 2023; 9:133. [PMID: 37087471 PMCID: PMC10121420 DOI: 10.1038/s41420-023-01420-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/22/2023] [Accepted: 03/29/2023] [Indexed: 04/24/2023] Open
Abstract
The ADP-ribosyltransferase, PARP1 enzymatically generates and applies the post-translational modification, ADP-Ribose (ADPR). PARP1 roles in genome maintenance are well described, but recent work highlights roles in many fundamental processes including cellular identity and energy homeostasis. Herein, we show in both mouse and human skeletal muscle cells that PARP1-mediated PARylation is a regulator of the myogenic program and the muscle transcriptional response to steroid hormones. Chemical PARP1 modulation impacts the expression of major myocellular proteins, including troponins, key in dictating muscle contractile force. Whilst PARP1 in absence of DNA damage is often assumed to be basally inactive, we show PARylation to be acutely sensitive to extracellular glucose concentrations and the steroid hormone class, glucocorticoids which exert considerable authority over muscle tissue mass. Specifically, we find during myogenesis, a transient and significant rise in PAR. This early-stage differentiation event, if blocked with PARP1 inhibition, reduced the abundance of important muscle proteins in the fully differentiated myotubes. This suggests that PAR targets during early-stage differentiation are central to the proper development of the muscle contractile unit. We also show that reduced PARP1 in myoblasts impacts a variety of metabolic pathways in line with the recorded actions of glucocorticoids. Currently, as both regulators of myogenesis and muscle mass loss, glucocorticoids represent a clinical conundrum. Our work goes on to identify that PARP1 influences transcriptional activation by glucocorticoids of a subset of genes critical to human skeletal muscle pathology. These genes may therefore signify a regulatory battery of targets through which selective glucocorticoid modulation could be achieved. Collectively, our data provide clear links between PARP1-mediated PARylation and skeletal muscle homeostatic mechanisms crucial to tissue mass maintenance and endocrine response.
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Affiliation(s)
- Arnold Tan
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Awais Z Younis
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Alexander Evans
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Jade V Creighton
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Clare Coveny
- John van Geest Cancer Research Centre, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - David J Boocock
- John van Geest Cancer Research Centre, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Craig Sale
- Institute of Sport, Manchester Metropolitan University, Manchester, M1 7EL, UK
| | - Gareth G Lavery
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Amanda S Coutts
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Craig L Doig
- School of Science and Technology, Department of Biosciences, Nottingham Trent University, Nottingham, NG11 8NS, UK.
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7
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ATM suppresses c-Myc overexpression in the mammary epithelium in response to estrogen. Cell Rep 2023; 42:111909. [PMID: 36640339 PMCID: PMC10023214 DOI: 10.1016/j.celrep.2022.111909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/27/2022] [Accepted: 12/12/2022] [Indexed: 12/31/2022] Open
Abstract
ATM gene mutation carriers are predisposed to estrogen-receptor-positive breast cancer (BC). ATM prevents BC oncogenesis by activating p53 in every cell; however, much remains unknown about tissue-specific oncogenesis after ATM loss. Here, we report that ATM controls the early transcriptional response to estrogens. This response depends on topoisomerase II (TOP2), which generates TOP2-DNA double-strand break (DSB) complexes and rejoins the breaks. When TOP2-mediated ligation fails, ATM facilitates DSB repair. After estrogen exposure, TOP2-dependent DSBs arise at the c-MYC enhancer in human BC cells, and their defective repair changes the activation profile of enhancers and induces the overexpression of many genes, including the c-MYC oncogene. CRISPR/Cas9 cleavage at the enhancer also causes c-MYC overexpression, indicating that this DSB causes c-MYC overexpression. Estrogen treatment induced c-Myc protein overexpression in mammary epithelial cells of ATM-deficient mice. In conclusion, ATM suppresses the c-Myc-driven proliferative effects of estrogens, possibly explaining such tissue-specific oncogenesis.
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8
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Taspase1 Facilitates Topoisomerase IIβ-Mediated DNA Double-Strand Breaks Driving Estrogen-Induced Transcription. Cells 2023; 12:cells12030363. [PMID: 36766705 PMCID: PMC9913075 DOI: 10.3390/cells12030363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/20/2023] Open
Abstract
The human protease Taspase1 plays a pivotal role in developmental processes and cancerous diseases by processing critical regulators, such as the leukemia proto-oncoprotein MLL. Despite almost two decades of intense research, Taspase1's biology is, however, still poorly understood, and so far its cellular function was not assigned to a superordinate biological pathway or a specific signaling cascade. Our data, gained by methods such as co-immunoprecipitation, LC-MS/MS and Topoisomerase II DNA cleavage assays, now functionally link Taspase1 and hormone-induced, Topoisomerase IIβ-mediated transient DNA double-strand breaks, leading to active transcription. The specific interaction with Topoisomerase IIα enhances the formation of DNA double-strand breaks that are a key prerequisite for stimulus-driven gene transcription. Moreover, Taspase1 alters the H3K4 epigenetic signature upon estrogen-stimulation by cleaving the chromatin-modifying enzyme MLL. As estrogen-driven transcription and MLL-derived epigenetic labelling are reduced upon Taspase1 siRNA-mediated knockdown, we finally characterize Taspase1 as a multifunctional co-activator of estrogen-stimulated transcription.
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9
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Stubbs FE, Flynn BP, Rivers CA, Birnie MT, Herman A, Swinstead EE, Baek S, Fang H, Temple J, Carroll JS, Hager GL, Lightman SL, Conway-Campbell BL. Identification of a novel GR-ARID1a-P53BP1 protein complex involved in DNA damage repair and cell cycle regulation. Oncogene 2022; 41:5347-5360. [PMID: 36344675 PMCID: PMC9734058 DOI: 10.1038/s41388-022-02516-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/02/2022] [Accepted: 10/17/2022] [Indexed: 11/09/2022]
Abstract
ARID1a (BAF250), a component of human SWI/SNF chromatin remodeling complexes, is frequently mutated across numerous cancers, and its loss of function has been putatively linked to glucocorticoid resistance. Here, we interrogate the impact of siRNA knockdown of ARID1a compared to a functional interference approach in the HeLa human cervical cancer cell line. We report that ARID1a knockdown resulted in a significant global decrease in chromatin accessibility in ATAC-Seq analysis, as well as affecting a subset of genome-wide GR binding sites determined by analyzing GR ChIP-Seq data. Interestingly, the specific effects on gene expression were limited to a relatively small subset of glucocorticoid-regulated genes, notably those involved in cell cycle regulation and DNA repair. The vast majority of glucocorticoid-regulated genes were largely unaffected by ARID1a knockdown or functional interference, consistent with a more specific role for ARID1a in glucocorticoid function than previously speculated. Using liquid chromatography-mass spectrometry, we have identified a chromatin-associated protein complex comprising GR, ARID1a, and several DNA damage repair proteins including P53 binding protein 1 (P53BP1), Poly(ADP-Ribose) Polymerase 1 (PARP1), DNA damage-binding protein 1 (DDB1), DNA mismatch repair protein MSH6 and splicing factor proline and glutamine-rich protein (SFPQ), as well as the histone acetyltransferase KAT7, an epigenetic regulator of steroid-dependent transcription, DNA damage repair and cell cycle regulation. Not only was this protein complex ablated with both ARID1a knockdown and functional interference, but spontaneously arising DNA damage was also found to accumulate in a manner consistent with impaired DNA damage repair mechanisms. Recovery from dexamethasone-dependent cell cycle arrest was also significantly impaired. Taken together, our data demonstrate that although glucocorticoids can still promote cell cycle arrest in the absence of ARID1a, the purpose of this arrest to allow time for DNA damage repair is hindered.
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Affiliation(s)
- Felicity E Stubbs
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
- Laboratory of Receptor Biology and Gene Expression, The National Cancer Institute, US National Institutes of Health, 41 Medlars Drive, Bethesda, MD, 20892, USA
| | - Benjamin P Flynn
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
| | - Caroline A Rivers
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
| | - Matthew T Birnie
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
| | - Andrew Herman
- Flow Cytometry Facility, Faculty of Life Sciences, School of Cellular & Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Erin E Swinstead
- Laboratory of Receptor Biology and Gene Expression, The National Cancer Institute, US National Institutes of Health, 41 Medlars Drive, Bethesda, MD, 20892, USA
| | - Songjoon Baek
- Laboratory of Receptor Biology and Gene Expression, The National Cancer Institute, US National Institutes of Health, 41 Medlars Drive, Bethesda, MD, 20892, USA
| | - Hai Fang
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Jillian Temple
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge, CB2 0RE, UK
| | - Jason S Carroll
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge, CB2 0RE, UK
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, The National Cancer Institute, US National Institutes of Health, 41 Medlars Drive, Bethesda, MD, 20892, USA
| | - Stafford L Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
| | - Becky L Conway-Campbell
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK.
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10
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Uusküla-Reimand L, Wilson MD. Untangling the roles of TOP2A and TOP2B in transcription and cancer. SCIENCE ADVANCES 2022; 8:eadd4920. [PMID: 36322662 PMCID: PMC9629710 DOI: 10.1126/sciadv.add4920] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/12/2022] [Indexed: 06/09/2023]
Abstract
Type II topoisomerases (TOP2) are conserved regulators of chromatin topology that catalyze reversible DNA double-strand breaks (DSBs) and are essential for maintaining genomic integrity in diverse dynamic processes such as transcription, replication, and cell division. While controlled TOP2-mediated DSBs are an elegant solution to topological constraints of DNA, DSBs also contribute to the emergence of chromosomal translocations and mutations that drive cancer. The central importance of TOP2 enzymes as frontline chemotherapeutic targets is well known; however, their precise biological functions and impact in cancer development are still poorly understood. In this review, we provide an updated overview of TOP2A and TOP2B in the regulation of chromatin topology and transcription, and discuss the recent discoveries linking TOP2 activities with cancer pathogenesis.
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Affiliation(s)
- Liis Uusküla-Reimand
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Michael D. Wilson
- Genetics and Genome Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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11
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Cai Y, Cao H, Wang F, Zhang Y, Kapranov P. Complex genomic patterns of abasic sites in mammalian DNA revealed by a high-resolution SSiNGLe-AP method. Nat Commun 2022; 13:5868. [PMID: 36198706 PMCID: PMC9534904 DOI: 10.1038/s41467-022-33594-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 09/23/2022] [Indexed: 11/30/2022] Open
Abstract
DNA damage plays a critical role in biology and diseases; however, how different types of DNA lesions affect cellular functions is far from clear mostly due to the paucity of high-resolution methods that can map their locations in complex genomes, such as those of mammals. Here, we present the development and validation of SSiNGLe-AP method, which can map a common type of DNA damage, abasic (AP) sites, in a genome-wide and high-resolution manner. We apply this method to six different tissues of mice with different ages and human cancer cell lines. We find a nonrandom distribution of AP sites in the mammalian genome that exhibits dynamic enrichment at specific genomic locations, including single-nucleotide hotspots, and is significantly influenced by gene expression, age and tissue type in particular. Overall, these results suggest that we are only starting to understand the true complexities in the genomic patterns of DNA damage. Abasic (AP) sites represent a prominent type of DNA damage, yet the genomics of this lesion remains unexplored. Here, the authors report a method to map such sites at the nucleotide level in complex genomes and use it to extract complex age- and tissue-dependent patterns of AP sites in mammals.
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Affiliation(s)
- Ye Cai
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Huifen Cao
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China.
| | - Fang Wang
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Yufei Zhang
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China
| | - Philipp Kapranov
- Institute of Genomics, School of Medicine, Huaqiao University, 668 Jimei Road, 361021, Xiamen, China.
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12
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Papapietro O, Nejentsev S. Topoisomerase 2β and DNA topology during B cell development. Front Immunol 2022; 13:982870. [PMID: 36045673 PMCID: PMC9423374 DOI: 10.3389/fimmu.2022.982870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Topoisomerase 2β (TOP2B) introduces transient double strand breaks in the DNA helix to remove supercoiling structures and unwind entangled DNA strains. Advances in genomic technologies have enabled the discovery of novel functions for TOP2B in processes such as releasing of the paused RNA polymerase II and maintaining the genome organization through DNA loop domains. Thus, TOP2B can regulate transcription directly by acting on transcription elongation and indirectly by controlling interactions between enhancer and promoter regions through genome folding. The identification of TOP2B mutations in humans unexpectedly revealed a unique role of TOP2B in B-cell progenitors. Here we discuss the functions of TOP2B and the mechanisms leading to the B-cell development defect in patients with TOP2B deficiency.
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Affiliation(s)
- Olivier Papapietro
- Molecular Cell Biology and Immunology, Amsterdam University Medical Centers (UMC), Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Infection and Immunity, Infectious Diseases, Amsterdam, Netherlands
- *Correspondence: Sergey Nejentsev, ; Olivier Papapietro,
| | - Sergey Nejentsev
- Molecular Cell Biology and Immunology, Amsterdam University Medical Centers (UMC), Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Amsterdam Infection and Immunity, Infectious Diseases, Amsterdam, Netherlands
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Sergey Nejentsev, ; Olivier Papapietro,
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13
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Cao H, Zhang Y, Cai Y, Tang L, Gao F, Xu D, Kapranov P. Hotspots of single-strand DNA “breakome” are enriched at transcriptional start sites of genes. Front Mol Biosci 2022; 9:895795. [PMID: 36046604 PMCID: PMC9420937 DOI: 10.3389/fmolb.2022.895795] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/27/2022] [Indexed: 01/01/2023] Open
Abstract
Single-strand breaks (SSBs) represent one of the most common types of DNA damage, yet not much is known about the genome landscapes of this type of DNA lesions in mammalian cells. Here, we found that SSBs are more likely to occur in certain positions of the human genome—SSB hotspots—in different cells of the same cell type and in different cell types. We hypothesize that the hotspots are likely to represent biologically relevant breaks. Furthermore, we found that the hotspots had a prominent tendency to be enriched in the immediate vicinity of transcriptional start sites (TSSs). We show that these hotspots are not likely to represent technical artifacts or be caused by common mechanisms previously found to cause DNA cleavage at promoters, such as apoptotic DNA fragmentation or topoisomerase type II (TOP2) activity. Therefore, such TSS-associated hotspots could potentially be generated using a novel mechanism that could involve preferential cleavage at cytosines, and their existence is consistent with recent studies suggesting a complex relationship between DNA damage and regulation of gene expression.
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14
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Khazeem MM, Casement JW, Schlossmacher G, Kenneth NS, Sumbung NK, Chan JYT, McGow JF, Cowell IG, Austin CA. TOP2B Is Required to Maintain the Adrenergic Neural Phenotype and for ATRA-Induced Differentiation of SH-SY5Y Neuroblastoma Cells. Mol Neurobiol 2022; 59:5987-6008. [PMID: 35831557 PMCID: PMC9463316 DOI: 10.1007/s12035-022-02949-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/23/2022] [Indexed: 12/13/2022]
Abstract
The neuroblastoma cell line SH-SY5Y is widely used to study retinoic acid (RA)-induced gene expression and differentiation and as a tool to study neurodegenerative disorders. SH-SY5Y cells predominantly exhibit adrenergic neuronal properties, but they can also exist in an epigenetically interconvertible alternative state with more mesenchymal characteristics; as a result, these cells can be used to study gene regulation circuitry controlling neuroblastoma phenotype. Using a combination of pharmacological inhibition and targeted gene inactivation, we have probed the requirement for DNA topoisomerase IIB (TOP2B) in RA-induced gene expression and differentiation and in the balance between adrenergic neuronal versus mesenchymal transcription programmes. We found that expression of many, but not all genes that are rapidly induced by ATRA in SH-SY5Y cells was significantly reduced in the TOP2B null cells; these genes include BCL2, CYP26A1, CRABP2, and NTRK2. Comparing gene expression profiles in wild-type versus TOP2B null cells, we found that long genes and genes expressed at a high level in WT SH-SY5Y cells were disproportionately dependent on TOP2B. Notably, TOP2B null SH-SY5Y cells upregulated mesenchymal markers vimentin (VIM) and fibronectin (FN1) and components of the NOTCH signalling pathway. Enrichment analysis and comparison with the transcription profiles of other neuroblastoma-derived cell lines supported the conclusion that TOP2B is required to fully maintain the adrenergic neural-like transcriptional signature of SH-SY5Y cells and to suppress the alternative mesenchymal epithelial-like epigenetic state.
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Affiliation(s)
- Mushtaq M Khazeem
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,National Center of Hematology, Mustansiriyah University, Baghdad, Iraq
| | - John W Casement
- Bioinformatics Support Unit, The Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - George Schlossmacher
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Niall S Kenneth
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.,Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Nielda K Sumbung
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Janice Yuen Tung Chan
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Jade F McGow
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Ian G Cowell
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
| | - Caroline A Austin
- The Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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15
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A tale of topoisomerases and the knotty genetic material in the backdrop of Plasmodium biology. Biosci Rep 2022; 42:231351. [PMID: 35699968 PMCID: PMC9261774 DOI: 10.1042/bsr20212847] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 05/05/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022] Open
Abstract
The untangling or overwinding of genetic material is an inevitable part of DNA
replication, repair, recombination, and transcription. Topoisomerases belong to
a conserved enzyme family that amends DNA topology during various processes of
DNA metabolism. To relax the genetic material, topoisomerases transiently break
the phosphodiester bond on one or both DNA strands and remain associated with
the cleavage site by forming a covalent enzyme–DNA intermediate. This
releases torsional stress and allows the broken DNA to be re-ligated by the
enzyme. The biological function of topoisomerases ranges from the separation of
sister chromatids following DNA replication to the aiding of chromosome
condensation and segregation during mitosis. Topoisomerases are also actively
involved in meiotic recombination. The unicellular apicomplexan parasite,
Plasmodium falciparum, harbors different topoisomerase
subtypes, some of which have substantially different sequences and functions
from their human counterparts. This review highlights the biological function of
each identified Plasmodium topoisomerase along with a
comparative analysis of their orthologs in human or other model organisms. There
is also a focus on recent advancements towards the development of topoisomerase
chemical inhibitors, underscoring the druggability of unique topoisomerase
subunits that are absent in humans. Plasmodium harbors three
distinct genomes in the nucleus, apicoplast, and mitochondria, respectively, and
undergoes non-canonical cell division during the schizont stage of development.
This review emphasizes the specific developmental stages of
Plasmodium on which future topoisomerase research should
focus.
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16
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Jafari H, Hussain S, Campbell MJ. Nuclear Receptor Coregulators in Hormone-Dependent Cancers. Cancers (Basel) 2022; 14:2402. [PMID: 35626007 PMCID: PMC9139824 DOI: 10.3390/cancers14102402] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 05/09/2022] [Indexed: 12/10/2022] Open
Abstract
Nuclear receptors (NRs) function collectively as a transcriptional signaling network that mediates gene regulatory actions to either maintain cellular homeostasis in response to hormonal, dietary and other environmental factors, or act as orphan receptors with no known ligand. NR complexes are large and interact with multiple protein partners, collectively termed coregulators. Coregulators are essential for regulating NR activity and can dictate whether a target gene is activated or repressed by a variety of mechanisms including the regulation of chromatin accessibility. Altered expression of coregulators contributes to a variety of hormone-dependent cancers including breast and prostate cancers. Therefore, understanding the mechanisms by which coregulators interact with and modulate the activity of NRs provides opportunities to develop better prognostic and diagnostic approaches, as well as novel therapeutic targets. This review aims to gather and summarize recent studies, techniques and bioinformatics methods used to identify distorted NR coregulator interactions that contribute as cancer drivers in hormone-dependent cancers.
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Affiliation(s)
- Hedieh Jafari
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA;
- Department of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA;
| | - Shahid Hussain
- Department of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA;
| | - Moray J. Campbell
- Department of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA;
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Saayman X, Esashi F. Breaking the paradigm: early insights from mammalian DNA breakomes. FEBS J 2022; 289:2409-2428. [PMID: 33792193 PMCID: PMC9451923 DOI: 10.1111/febs.15849] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/04/2021] [Accepted: 03/29/2021] [Indexed: 12/13/2022]
Abstract
DNA double-strand breaks (DSBs) can result from both exogenous and endogenous sources and are potentially toxic lesions to the human genome. If improperly repaired, DSBs can threaten genome integrity and contribute to premature ageing, neurodegenerative disorders and carcinogenesis. Through decades of work on genome stability, it has become evident that certain regions of the genome are inherently more prone to breakage than others, known as genome instability hotspots. Recent advancements in sequencing-based technologies now enable the profiling of genome-wide distributions of DSBs, also known as breakomes, to systematically map these instability hotspots. Here, we review the application of these technologies and their implications for our current understanding of the genomic regions most likely to drive genome instability. These breakomes ultimately highlight both new and established breakage hotspots including actively transcribed regions, loop boundaries and early-replicating regions of the genome. Further, these breakomes challenge the paradigm that DNA breakage primarily occurs in hard-to-replicate regions. With these advancements, we begin to gain insights into the biological mechanisms both invoking and protecting against genome instability.
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Affiliation(s)
- Xanita Saayman
- Sir William Dunn School of Pathology, University of Oxford, UK
| | - Fumiko Esashi
- Sir William Dunn School of Pathology, University of Oxford, UK
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18
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Crewe M, Madabhushi R. Topoisomerase-Mediated DNA Damage in Neurological Disorders. Front Aging Neurosci 2021; 13:751742. [PMID: 34899270 PMCID: PMC8656403 DOI: 10.3389/fnagi.2021.751742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/23/2021] [Indexed: 12/12/2022] Open
Abstract
The nervous system is vulnerable to genomic instability and mutations in DNA damage response factors lead to numerous developmental and progressive neurological disorders. Despite this, the sources and mechanisms of DNA damage that are most relevant to the development of neuronal dysfunction are poorly understood. The identification of primarily neurological abnormalities in patients with mutations in TDP1 and TDP2 suggest that topoisomerase-mediated DNA damage could be an important underlying source of neuronal dysfunction. Here we review the potential sources of topoisomerase-induced DNA damage in neurons, describe the cellular mechanisms that have evolved to repair such damage, and discuss the importance of these repair mechanisms for preventing neurological disorders.
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19
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TOP2B's contributions to transcription. Biochem Soc Trans 2021; 49:2483-2493. [PMID: 34747992 DOI: 10.1042/bst20200454] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/07/2021] [Accepted: 10/11/2021] [Indexed: 12/23/2022]
Abstract
Transcription is regulated and mediated by multiprotein complexes in a chromatin context. Transcription causes changes in DNA topology which is modulated by DNA topoisomerases, enzymes that catalyse changes in DNA topology via transient breaking and re-joining of one or both strands of the phosphodiester backbone. Mammals have six DNA topoisomerases, this review focuses on one, DNA topoisomerase II beta (TOP2B). In the absence of TOP2B transcription of many developmentally regulated genes is altered. Long genes seem particularly susceptible to the lack of TOP2B. Biochemical studies of the role of TOP2B in transcription regulated by ligands such as nuclear hormones, growth factors and insulin has revealed PARP1 associated with TOP2B and also PRKDC, XRCC5 and XRCC6. Analysis of publicly available databases of protein interactions confirms these interactions and illustrates interactions with other key transcriptional regulators including TRIM28. TOP2B has been shown to interact with proteins involved in chromosome organisation including CTCF and RAD21. Comparison of publicly available Chip-seq datasets reveals the location at which these proteins interact with genes. The availability of resources such as large datasets of protein-protein interactions, e.g. BioGrid and IntAct and protein-DNA interactions such as Chip-seq in GEO enables scientists to extend models and propose new hypotheses.
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20
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Nucleolar translocation of human DNA topoisomerase II by ATP depletion and its disruption by the RNA polymerase I inhibitor BMH-21. Sci Rep 2021; 11:21533. [PMID: 34728715 PMCID: PMC8563764 DOI: 10.1038/s41598-021-00958-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
DNA topoisomerase II (TOP2) is a nuclear protein that resolves DNA topological problems and plays critical roles in multiple nuclear processes. Human cells have two TOP2 proteins, TOP2A and TOP2B, that are localized in both the nucleoplasm and nucleolus. Previously, ATP depletion was shown to augment the nucleolar localization of TOP2B, but the molecular details of subnuclear distributions, particularly of TOP2A, remained to be fully elucidated in relation to the status of cellular ATP. Here, we analyzed the nuclear dynamics of human TOP2A and TOP2B in ATP-depleted cells. Both proteins rapidly translocated from the nucleoplasm to the nucleolus in response to ATP depletion. FRAP analysis demonstrated that they were highly mobile in the nucleoplasm and nucleolus. The nucleolar retention of both proteins was sensitive to the RNA polymerase I inhibitor BMH-21, and the TOP2 proteins in the nucleolus were immediately dispersed into the nucleoplasm by BMH-21. Under ATP-depleted conditions, the TOP2 poison etoposide was less effective, indicating the therapeutic relevance of TOP2 subnuclear distributions. These results give novel insights into the subnuclear dynamics of TOP2 in relation to cellular ATP levels and also provide discussions about its possible mechanisms and biological significance.
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21
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Kowalik K, Waniewska-Leczycka M, Sarnowska E, Rusetska N, Ligaj M, Chrzan A, Popko M. The SWI/SNF complex in eosinophilic and non eosinophilic chronic rhinosinusitis. ACTA ACUST UNITED AC 2021; 41:159-167. [PMID: 34028461 PMCID: PMC8142725 DOI: 10.14639/0392-100x-n0760] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 11/09/2020] [Indexed: 01/02/2023]
Abstract
Introduction Chronic rhinosinusitis (CRS) can be classified as eosinophilic (eCRS) or non-eosinophilic (neCRS) based on infiltration type. The SWI/SNF complex may be involved in the pathophysiology of CRS. Aim To assess the expression of the SWI/SNF complex in both CRS groups; to correlate blood eosinophil count (BEC), and histopathology eosinophil count (HPEC) with the SWI/SNF expression level in eCRS and neCRS. Materials and methods The study population consisted of 96 patients (68 eCRS, 28 neCRS). Immunohistochemical staining was performed on sinonasal mucosa for assessment of SWI/SNF protein expression. Type of tissue infiltration was assessed in samples obtained from examined groups (HPEC). The diagnostic value of eCRS was 10 cells/HPF (high power field). Complete blood count was analysed in order to calculate BEC. Results BEC and HPEC correlated negatively with all the SWI/SNF subunits. HPEC and BEC correlated positively with clinical findings (L-M and SNOT-22), while SWI/SNF correlated negatively with clinical findings (L-M and SNOT-22). Conclusions The SWI/SNF was observed in both eCRS and neCRS, with lower expression in former. The meaning of its negative correlation with BEC, HPEC and clinical findings in eCRS group remains to be understood.
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Affiliation(s)
- Katarzyna Kowalik
- Department of Otorhinolaryngology, Faculty of Medicine and Dentistry, Medical University of Warsaw, Warsaw, Poland
| | - Martyna Waniewska-Leczycka
- Department of Otorhinolaryngology, Faculty of Medicine and Dentistry, Medical University of Warsaw, Warsaw, Poland
| | - Elzbieta Sarnowska
- Department of Molecular and Translational Oncology, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Natalia Rusetska
- Department of Molecular and Translational Oncology, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Marcin Ligaj
- Department of Pathology, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Alicja Chrzan
- Department of Pathology, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
| | - Mariola Popko
- Department of Otorhinolaryngology, Faculty of Medicine and Dentistry, Medical University of Warsaw, Warsaw, Poland
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22
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Cristini A, Géraud M, Sordet O. Transcription-associated DNA breaks and cancer: A matter of DNA topology. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 364:195-240. [PMID: 34507784 DOI: 10.1016/bs.ircmb.2021.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transcription is an essential cellular process but also a major threat to genome integrity. Transcription-associated DNA breaks are particularly detrimental as their defective repair can induce gene mutations and oncogenic chromosomal translocations, which are hallmarks of cancer. The past few years have revealed that transcriptional breaks mainly originate from DNA topological problems generated by the transcribing RNA polymerases. Defective removal of transcription-induced DNA torsional stress impacts on transcription itself and promotes secondary DNA structures, such as R-loops, which can induce DNA breaks and genome instability. Paradoxically, as they relax DNA during transcription, topoisomerase enzymes introduce DNA breaks that can also endanger genome integrity. Stabilization of topoisomerases on chromatin by various anticancer drugs or by DNA alterations, can interfere with transcription machinery and cause permanent DNA breaks and R-loops. Here, we review the role of transcription in mediating DNA breaks, and discuss how deregulation of topoisomerase activity can impact on transcription and DNA break formation, and its connection with cancer.
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Affiliation(s)
- Agnese Cristini
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.
| | - Mathéa Géraud
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France
| | - Olivier Sordet
- Cancer Research Center of Toulouse, INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.
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23
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Abbasi S, Parmar G, Kelly RD, Balasuriya N, Schild-Poulter C. The Ku complex: recent advances and emerging roles outside of non-homologous end-joining. Cell Mol Life Sci 2021; 78:4589-4613. [PMID: 33855626 PMCID: PMC11071882 DOI: 10.1007/s00018-021-03801-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/29/2021] [Accepted: 02/24/2021] [Indexed: 12/15/2022]
Abstract
Since its discovery in 1981, the Ku complex has been extensively studied under multiple cellular contexts, with most work focusing on Ku in terms of its essential role in non-homologous end-joining (NHEJ). In this process, Ku is well-known as the DNA-binding subunit for DNA-PK, which is central to the NHEJ repair process. However, in addition to the extensive study of Ku's role in DNA repair, Ku has also been implicated in various other cellular processes including transcription, the DNA damage response, DNA replication, telomere maintenance, and has since been studied in multiple contexts, growing into a multidisciplinary point of research across various fields. Some advances have been driven by clarification of Ku's structure, including the original Ku crystal structure and the more recent Ku-DNA-PKcs crystallography, cryogenic electron microscopy (cryoEM) studies, and the identification of various post-translational modifications. Here, we focus on the advances made in understanding the Ku heterodimer outside of non-homologous end-joining, and across a variety of model organisms. We explore unique structural and functional aspects, detail Ku expression, conservation, and essentiality in different species, discuss the evidence for its involvement in a diverse range of cellular functions, highlight Ku protein interactions and recent work concerning Ku-binding motifs, and finally, we summarize the clinical Ku-related research to date.
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Affiliation(s)
- Sanna Abbasi
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Gursimran Parmar
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Rachel D Kelly
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Nileeka Balasuriya
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Caroline Schild-Poulter
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada.
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25
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Paakinaho V, Lempiäinen JK, Sigismondo G, Niskanen EA, Malinen M, Jääskeläinen T, Varjosalo M, Krijgsveld J, Palvimo J. SUMOylation regulates the protein network and chromatin accessibility at glucocorticoid receptor-binding sites. Nucleic Acids Res 2021; 49:1951-1971. [PMID: 33524141 PMCID: PMC7913686 DOI: 10.1093/nar/gkab032] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 12/13/2022] Open
Abstract
Glucocorticoid receptor (GR) is an essential transcription factor (TF), controlling metabolism, development and immune responses. SUMOylation regulates chromatin occupancy and target gene expression of GR in a locus-selective manner, but the mechanism of regulation has remained elusive. Here, we identify the protein network around chromatin-bound GR by using selective isolation of chromatin-associated proteins and show that the network is affected by receptor SUMOylation, with several nuclear receptor coregulators and chromatin modifiers preferring interaction with SUMOylation-deficient GR and proteins implicated in transcriptional repression preferring interaction with SUMOylation-competent GR. This difference is reflected in our chromatin binding, chromatin accessibility and gene expression data, showing that the SUMOylation-deficient GR is more potent in binding and opening chromatin at glucocorticoid-regulated enhancers and inducing expression of target loci. Blockage of SUMOylation by a SUMO-activating enzyme inhibitor (ML-792) phenocopied to a large extent the consequences of GR SUMOylation deficiency on chromatin binding and target gene expression. Our results thus show that SUMOylation modulates the specificity of GR by regulating its chromatin protein network and accessibility at GR-bound enhancers. We speculate that many other SUMOylated TFs utilize a similar regulatory mechanism.
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Affiliation(s)
- Ville Paakinaho
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | | | | | - Einari A Niskanen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Marjo Malinen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Tiina Jääskeläinen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jeroen Krijgsveld
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Medical Faculty, Heidelberg, Germany
| | - Jorma J Palvimo
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
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Sutormin DA, Galivondzhyan AK, Polkhovskiy AV, Kamalyan SO, Severinov KV, Dubiley SA. Diversity and Functions of Type II Topoisomerases. Acta Naturae 2021; 13:59-75. [PMID: 33959387 PMCID: PMC8084294 DOI: 10.32607/actanaturae.11058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/09/2020] [Indexed: 11/29/2022] Open
Abstract
The DNA double helix provides a simple and elegant way to store and copy genetic information. However, the processes requiring the DNA helix strands separation, such as transcription and replication, induce a topological side-effect - supercoiling of the molecule. Topoisomerases comprise a specific group of enzymes that disentangle the topological challenges associated with DNA supercoiling. They relax DNA supercoils and resolve catenanes and knots. Here, we review the catalytic cycles, evolution, diversity, and functional roles of type II topoisomerases in organisms from all domains of life, as well as viruses and other mobile genetic elements.
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Affiliation(s)
- D. A. Sutormin
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
| | - A. K. Galivondzhyan
- Lomonosov Moscow State University, Moscow, 119991 Russia
- Institute of Molecular Genetics RAS, Moscow, 123182 Russia
| | - A. V. Polkhovskiy
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
| | - S. O. Kamalyan
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
| | - K. V. Severinov
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
- Centre for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology RAS, Moscow, 119334 Russia
- Waksman Institute for Microbiology, Piscataway, New Jersey, 08854 USA
| | - S. A. Dubiley
- Institute of Gene Biology RAS, Moscow, 119334 Russia
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
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28
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Li TT, Zhu HB. LKB1 and cancer: The dual role of metabolic regulation. Biomed Pharmacother 2020; 132:110872. [PMID: 33068936 DOI: 10.1016/j.biopha.2020.110872] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/07/2020] [Accepted: 10/07/2020] [Indexed: 02/07/2023] Open
Abstract
Liver kinase B1 (LKB1) is an essential serine/threonine kinase frequently associated with Peutz-Jeghers syndrome (PJS). In this review, we provide an overview of the role of LKB1 in conferring protection to cancer cells against metabolic stress and promoting cancer cell survival and invasion. This carcinogenic effect contradicts the previous conclusion that LKB1 is a tumor suppressor gene. Here we try to explain the contradictory effect of LKB1 on cancer from a metabolic perspective. Upon deletion of LKB1, cancer cells experience increased energy as well as oxidative stress, thereby causing genomic instability. Meanwhile, mutated LKB1 cooperates with other metabolic regulatory genes to promote metabolic reprogramming that subsequently facilitates adaptation to strong metabolic stress, resulting in development of a more aggressive malignant phenotype. We aim to specifically discuss the contradictory role of LKB1 in cancer by reviewing the mechanism of LKB1 with an emphasis on metabolic stress and metabolic reprogramming.
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Affiliation(s)
- Ting-Ting Li
- Department of Gynecology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
| | - Hai-Bin Zhu
- Department of Gynecology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China.
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Zagnoli-Vieira G, Caldecott KW. Untangling trapped topoisomerases with tyrosyl-DNA phosphodiesterases. DNA Repair (Amst) 2020; 94:102900. [PMID: 32653827 DOI: 10.1016/j.dnarep.2020.102900] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/14/2020] [Accepted: 06/14/2020] [Indexed: 02/08/2023]
Abstract
DNA topoisomerases alleviate the torsional stress that is generated by processes that are central to genome metabolism such as transcription and DNA replication. To do so, these enzymes generate an enzyme intermediate known as the cleavage complex in which the topoisomerase is covalently linked to the termini of a DNA single- or double-strand break. Whilst cleavage complexes are normally transient they can occasionally become abortive, creating protein-linked DNA breaks that threaten genome stability and cell survival; a process promoted and exploited in the cancer clinic by the use of topoisomerase 'poisons'. Here, we review the consequences to genome stability and human health of abortive topoisomerase-induced DNA breakage and the cellular pathways that cells have adopted to mitigate them, with particular focus on an important class of enzymes known as tyrosyl-DNA phosphodiesterases.
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Affiliation(s)
- Guido Zagnoli-Vieira
- Wellcome Trust Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge, CB2 1QN, UK.
| | - Keith W Caldecott
- Genome Damage Stability Centre, University of Sussex, Falmer Road, Brighton, BN1 9RQ, UK.
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30
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Gormally BMG, Estrada R, McVey M, Romero LM. Beyond corticosterone: The acute stress response increases DNA damage in house sparrows. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 333:595-606. [PMID: 32798291 DOI: 10.1002/jez.2405] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 08/02/2020] [Indexed: 12/22/2022]
Abstract
Although corticosterone (Cort) has been the predominant metric used to assess acute stress in birds, it does not always accurately reflect how an animal copes with a stressor. Downstream measurements may be more reliable. In the current study, we tested the hypothesis that acute increases in DNA damage could be used to assess stressor exposure. Studies have shown DNA damage increases in response to stress-related hormones in vitro; however, this has not yet been thoroughly applied in wild animals. We exposed house sparrows (Passer domesticus) to a 30- or 120-min restraint stressor and took blood samples at 0, 30, 60, and 120 min to measure Cort, DNA damage, and uric acid. Both treatments increased DNA damage and Cort, and decreased uric acid. It thus appears that DNA damage can reflect acute stressor exposure. To improve the usability of DNA damage as a metric for stress, we also tested the impacts of sample storage on DNA damage. Leaving red blood cells on ice for up to 24 hr, only slightly influenced DNA damage. Freezing blood samples for 1-4 weeks substantially increased DNA damage. These findings emphasize the importance of reducing variation between samples by assaying them together whenever possible. Overall, these results indicate that assessing DNA damage is a valid method of assessing acute stressor exposure that is suitable for both laboratory- and field-based studies; however, additional research is needed on the molecular dynamics of nucleated red blood cells, including whether and how their DNA is repaired.
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Affiliation(s)
| | - Rodolfo Estrada
- Department of Biology, Tufts University, Medford, Massachusetts
| | - Mitch McVey
- Department of Biology, Tufts University, Medford, Massachusetts
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31
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Khazeem MM, Cowell IG, Harkin LF, Casement JW, Austin CA. Transcription of carbonyl reductase 1 is regulated by DNA topoisomerase II beta. FEBS Lett 2020; 594:3395-3405. [PMID: 32767399 DOI: 10.1002/1873-3468.13904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 12/16/2022]
Abstract
DNA topoisomerase II beta (TOP2B) has a role in transcriptional regulation. Here, to further investigate transcriptional regulation by TOP2B, we used RNA-sequencing and real-time PCR to analyse the differential gene expression profiles of wild-type and two independent TOP2B-null pre-B Nalm-6 cell lines, one generated by targeted insertion and the other using CRISPR-Cas9 gene editing. We identified carbonyl reductase 1 (CBR1) among the most significantly downregulated genes in these TOP2B-null cells. Reduced CBR1 expression was accompanied by loss of binding of the transcription factors USF2 and MAX to the CBR1 promoter. We describe possible mechanisms by which loss of TOP2B results in CBR1 downregulation. To our knowledge, this is the first report of a link between TOP2B and CBR1.
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Affiliation(s)
- Mushtaq M Khazeem
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Ian G Cowell
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Lauren F Harkin
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - John W Casement
- Bioinformatics Support Unit, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Caroline A Austin
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
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Abstract
Transcription in several organisms from certain bacteria to humans has been observed to be stochastic in nature: toggling between active and inactive states. Periods of active nascent RNA synthesis known as bursts represent individual gene activation events in which multiple polymerases are initiated. Therefore, bursting is the single locus illustration of both gene activation and repression. Although transcriptional bursting was originally observed decades ago, only recently have technological advances enabled the field to begin elucidating gene regulation at the single-locus level. In this review, we focus on how biochemical, genomic, and single-cell data describe the regulatory steps of transcriptional bursts.
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Affiliation(s)
- Joseph Rodriguez
- National Institute of Environmental Health Sciences, Durham, North Carolina 27709, USA
| | - Daniel R. Larson
- Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
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Jang Y, Elsayed Z, Eki R, He S, Du KP, Abbas T, Kai M. Intrinsically disordered protein RBM14 plays a role in generation of RNA:DNA hybrids at double-strand break sites. Proc Natl Acad Sci U S A 2020; 117:5329-5338. [PMID: 32094185 PMCID: PMC7071921 DOI: 10.1073/pnas.1913280117] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Accumulating evidence suggests participation of RNA-binding proteins with intrinsically disordered domains (IDPs) in the DNA damage response (DDR). These IDPs form liquid compartments at DNA damage sites in a poly(ADP ribose) (PAR)-dependent manner. However, it is greatly unknown how the IDPs are involved in DDR. We have shown previously that one of the IDPs RBM14 is required for the canonical nonhomologous end joining (cNHEJ). Here we show that RBM14 is recruited to DNA damage sites in a PARP- and RNA polymerase II (RNAPII)-dependent manner. Both KU and RBM14 are required for RNAPII-dependent generation of RNA:DNA hybrids at DNA damage sites. In fact, RBM14 binds to RNA:DNA hybrids. Furthermore, RNA:DNA hybrids and RNAPII are detected at gene-coding as well as at intergenic areas when double-strand breaks (DSBs) are induced. We propose that the cNHEJ pathway utilizes damage-induced transcription and intrinsically disordered protein RBM14 for efficient repair of DSBs.
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Affiliation(s)
- Yumi Jang
- Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21231
| | - Zeinab Elsayed
- Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21231
| | - Rebeka Eki
- Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, VA 22908
- Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Shuaixin He
- Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21231
| | - Kang-Ping Du
- Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, VA 22908
- Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Tarek Abbas
- Department of Radiation Oncology, University of Virginia School of Medicine, Charlottesville, VA 22908
- Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908
| | - Mihoko Kai
- Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21231;
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Contributions of DNA Damage to Alzheimer's Disease. Int J Mol Sci 2020; 21:ijms21051666. [PMID: 32121304 PMCID: PMC7084447 DOI: 10.3390/ijms21051666] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/20/2020] [Accepted: 02/25/2020] [Indexed: 12/16/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common type of neurodegenerative disease. Its typical pathology consists of extracellular amyloid-β (Aβ) plaques and intracellular tau neurofibrillary tangles. Mutations in the APP, PSEN1, and PSEN2 genes increase Aβ production and aggregation, and thus cause early onset or familial AD. Even with this strong genetic evidence, recent studies support AD to result from complex etiological alterations. Among them, aging is the strongest risk factor for the vast majority of AD cases: Sporadic late onset AD (LOAD). Accumulation of DNA damage is a well-established aging factor. In this regard, a large amount of evidence reveals DNA damage as a critical pathological cause of AD. Clinically, DNA damage is accumulated in brains of AD patients. Genetically, defects in DNA damage repair resulted from mutations in the BRAC1 and other DNA damage repair genes occur in AD brain and facilitate the pathogenesis. Abnormalities in DNA damage repair can be used as diagnostic biomarkers for AD. In this review, we discuss the association, the causative potential, and the biomarker values of DNA damage in AD pathogenesis.
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35
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Shadrina O, Garanina I, Korolev S, Zatsepin T, Van Assche J, Daouad F, Wallet C, Rohr O, Gottikh M. Analysis of RNA binding properties of human Ku protein reveals its interactions with 7SK snRNA and protein components of 7SK snRNP complex. Biochimie 2020; 171-172:110-123. [PMID: 32105815 DOI: 10.1016/j.biochi.2020.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/21/2020] [Indexed: 12/21/2022]
Abstract
Human Ku heterodimeric protein composed of Ku70 and Ku80 subunits plays an important role in the non-homologous end-joining DNA repair pathway as a sensor of double strand DNA breaks. Ku is also involved in numerous cellular processes, and in some of them it acts in an RNA-dependent manner. However, RNA binding properties of the human Ku have not been well studied. Here we have analyzed interactions of a recombinant Ku heterodimer with a set of RNAs of various structure as well as eCLIP (enhanced crosslinking and immunoprecipitation) data for human Ku70. As a result, we have proposed a consensus RNA structure preferable for the Ku binding that is a hairpin possessing a bulge just near GpG sequence-containing terminal loop. 7SK snRNA is a scaffold for a ribonucleoprotein complex (7SK snRNP), which is known to participate in transcription regulation. We have shown that the recombinant Ku specifically binds a G-rich loop of hairpin 1 within 7SK snRNA. Moreover, Ku protein has been co-precipitated from HEK 293T cells with endogenous 7SK snRNA and such proteins included in 7SK snRNP as HEXIM1, Cdk9 and CTIP2. Ku and Cdk9 binding is found to be RNA-independent, meanwhile HEXIM1 and Ku co-precipitation depended on the presence of intact 7SK snRNA. The latter result has been confirmed using recombinant HEXIM1 and Ku proteins. Colocalization of Ku and CTIP2 was additionally confirmed by confocal microscopy. These results allow us to propose human Ku as a new component of the 7SK snRNP complex.
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Affiliation(s)
- Olga Shadrina
- Chemistry Department, Lomonosov Moscow State University, Moscow, 199991, Russia; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia.
| | - Irina Garanina
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Sergey Korolev
- Chemistry Department, Lomonosov Moscow State University, Moscow, 199991, Russia; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia
| | - Timofei Zatsepin
- Chemistry Department, Lomonosov Moscow State University, Moscow, 199991, Russia; Skolkovo Institute of Science and Technology, Skolkovo, 121205, Russia
| | - Jeanne Van Assche
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Fadoua Daouad
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Clementine Wallet
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Olivier Rohr
- Université de Strasbourg, EA7292, FMTS, IUT Louis Pasteur, Schiltigheim, France
| | - Marina Gottikh
- Chemistry Department, Lomonosov Moscow State University, Moscow, 199991, Russia; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992, Moscow, Russia
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36
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NoRC Recruitment by H2A.X Deposition at rRNA Gene Promoter Limits Embryonic Stem Cell Proliferation. Cell Rep 2019; 23:1853-1866. [PMID: 29742439 DOI: 10.1016/j.celrep.2018.04.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 01/16/2018] [Accepted: 04/04/2018] [Indexed: 01/22/2023] Open
Abstract
Embryonic stem cells (ESCs) display an abbreviated cell cycle, resulting in a short doubling time and rapid proliferation. The histone variant H2A.X is critical for proliferation of stem cells, although mechanistic insights have remained obscure. Here, we show that H2A.X defines the rate of mouse ESC proliferation independently of the DNA damage response pathway, and it associates with three major chromatin-modifying complexes. Our functional and biochemical analyses demonstrate that H2A.X-associated factors mediate the H2A.X-dependent effect on ESC proliferation and involve the nucleolar remodeling complex (NoRC). A specific H2A.X deposition at rDNA promoters determines the chromatin recruitment of the NoRC, histone modifications, the rRNA transcription, and the rate of proliferation. Collectively, our results suggest that NoRC assembly by H2A.X deposition at rRNA promoters silences transcription, and this represents an important regulatory component for ESC proliferation.
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37
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Bétermier M, Borde V, de Villartay JP. Coupling DNA Damage and Repair: an Essential Safeguard during Programmed DNA Double-Strand Breaks? Trends Cell Biol 2019; 30:87-96. [PMID: 31818700 DOI: 10.1016/j.tcb.2019.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/15/2019] [Accepted: 11/18/2019] [Indexed: 12/31/2022]
Abstract
DNA double-strand breaks (DSBs) are the most toxic DNA lesions given their oncogenic potential. Nevertheless, programmed DSBs (prDSBs) contribute to several biological processes. Formation of prDSBs is the 'price to pay' to achieve these essential biological functions. Generated by domesticated PiggyBac transposases, prDSBs have been integrated in the life cycle of ciliates. Created by Spo11 during meiotic recombination, they constitute a driving force of evolution and ensure balanced chromosome content for successful reproduction. Produced by the RAG1/2 recombinase, they are required for the development of the adaptive immune system in many species. The coevolution of processes that couple introduction of prDSBs to their accurate repair may constitute an effective safeguard against genomic instability.
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Affiliation(s)
- Mireille Bétermier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France.
| | - Valérie Borde
- Institut Curie, CNRS UMR3244, Sorbonne Université, Paris, France.
| | - Jean-Pierre de Villartay
- Laboratory of Genome Dynamics in the Immune System, INSERM UMR1163, Université Paris Descartes Sorbonne Paris Cité, Institut Imagine, Paris, France.
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38
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Type II DNA Topoisomerases Cause Spontaneous Double-Strand Breaks in Genomic DNA. Genes (Basel) 2019; 10:genes10110868. [PMID: 31671674 PMCID: PMC6895833 DOI: 10.3390/genes10110868] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 12/31/2022] Open
Abstract
Type II DNA topoisomerase enzymes (TOP2) catalyze topological changes by strand passage reactions. They involve passing one intact double stranded DNA duplex through a transient enzyme-bridged break in another (gated helix) followed by ligation of the break by TOP2. A TOP2 poison, etoposide blocks TOP2 catalysis at the ligation step of the enzyme-bridged break, increasing the number of stable TOP2 cleavage complexes (TOP2ccs). Remarkably, such pathological TOP2ccs are formed during the normal cell cycle as well as in postmitotic cells. Thus, this ‘abortive catalysis’ can be a major source of spontaneously arising DNA double-strand breaks (DSBs). TOP2-mediated DSBs are also formed upon stimulation with physiological concentrations of androgens and estrogens. The frequent occurrence of TOP2-mediated DSBs was previously not appreciated because they are efficiently repaired. This repair is performed in collaboration with BRCA1, BRCA2, MRE11 nuclease, and tyrosyl-DNA phosphodiesterase 2 (TDP2) with nonhomologous end joining (NHEJ) factors. This review first discusses spontaneously arising DSBs caused by the abortive catalysis of TOP2 and then summarizes proteins involved in repairing stalled TOP2ccs and discusses the genotoxicity of the sex hormones.
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39
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Atkin ND, Raimer HM, Wang YH. Broken by the Cut: A Journey into the Role of Topoisomerase II in DNA Fragility. Genes (Basel) 2019; 10:E791. [PMID: 31614754 PMCID: PMC6826763 DOI: 10.3390/genes10100791] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/05/2019] [Accepted: 10/10/2019] [Indexed: 02/07/2023] Open
Abstract
DNA topoisomerase II (TOP2) plays a critical role in many processes such as replication and transcription, where it resolves DNA structures and relieves torsional stress. Recent evidence demonstrated the association of TOP2 with topologically associated domains (TAD) boundaries and CCCTC-binding factor (CTCF) binding sites. At these sites, TOP2 promotes interactions between enhancers and gene promoters, and relieves torsional stress that accumulates at these physical barriers. Interestingly, in executing its enzymatic function, TOP2 contributes to DNA fragility through re-ligation failure, which results in persistent DNA breaks when unrepaired or illegitimately repaired. Here, we discuss the biological processes for which TOP2 is required and the steps at which it can introduce DNA breaks. We describe the repair processes that follow removal of TOP2 adducts and the resultant broken DNA ends, and present how these processes can contribute to disease-associated mutations. Furthermore, we examine the involvement of TOP2-induced breaks in the formation of oncogenic translocations of leukemia and papillary thyroid cancer, as well as the role of TOP2 and proteins which repair TOP2 adducts in other diseases. The participation of TOP2 in generating persistent DNA breaks and leading to diseases such as cancer, could have an impact on disease treatment and prevention.
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Affiliation(s)
- Naomi D Atkin
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA.
| | - Heather M Raimer
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA.
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40
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Blower TR, Bandak A, Lee ASY, Austin CA, Nitiss JL, Berger JM. A complex suite of loci and elements in eukaryotic type II topoisomerases determine selective sensitivity to distinct poisoning agents. Nucleic Acids Res 2019; 47:8163-8179. [PMID: 31287876 PMCID: PMC6735899 DOI: 10.1093/nar/gkz579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 06/19/2019] [Accepted: 07/03/2019] [Indexed: 11/13/2022] Open
Abstract
Type II topoisomerases catalyze essential DNA transactions and are proven drug targets. Drug discrimination by prokaryotic and eukaryotic topoisomerases is vital to therapeutic utility, but is poorly understood. We developed a next-generation sequencing (NGS) approach to identify drug-resistance mutations in eukaryotic topoisomerases. We show that alterations conferring resistance to poisons of human and yeast topoisomerase II derive from a rich mutational 'landscape' of amino acid substitutions broadly distributed throughout the entire enzyme. Both general and discriminatory drug-resistant behaviors are found to arise from different point mutations found at the same amino acid position and to occur far outside known drug-binding sites. Studies of selected resistant enzymes confirm the NGS data and further show that the anti-cancer quinolone vosaroxin acts solely as an intercalating poison, and that the antibacterial ciprofloxacin can poison yeast topoisomerase II. The innate drug-sensitivity of the DNA binding and cleavage region of human and yeast topoisomerases (particularly hTOP2β) is additionally revealed to be significantly regulated by the enzymes' adenosine triphosphatase regions. Collectively, these studies highlight the utility of using NGS-based methods to rapidly map drug resistance landscapes and reveal that the nucleotide turnover elements of type II topoisomerases impact drug specificity.
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Affiliation(s)
- Tim R Blower
- Johns Hopkins University School of Medicine, Department of Biophysics and Biophysical Chemistry, Baltimore, MD 21205, USA
| | - Afif Bandak
- Johns Hopkins University School of Medicine, Department of Biophysics and Biophysical Chemistry, Baltimore, MD 21205, USA
| | - Amy S Y Lee
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Caroline A Austin
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - John L Nitiss
- Biopharmaceutical Sciences Department, University of Illinois College of Pharmacy, 1601 Parkview Avenue, N310, Rockford, IL 61107, USA
| | - James M Berger
- Johns Hopkins University School of Medicine, Department of Biophysics and Biophysical Chemistry, Baltimore, MD 21205, USA
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41
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Mackey LC, Annab LA, Yang J, Rao B, Kissling GE, Schurman SH, Dixon D, Archer TK. Epigenetic Enzymes, Age, and Ancestry Regulate the Efficiency of Human iPSC Reprogramming. Stem Cells 2018; 36:1697-1708. [PMID: 30152570 DOI: 10.1002/stem.2899] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 06/28/2018] [Accepted: 07/06/2018] [Indexed: 12/17/2022]
Abstract
Epigenetic enzymes regulate higher-order chromatin architecture and cell-type specific gene expression. The ATPase BRG1 and the SWI/SNF chromatin remodeling complex are epigenetic enzymes that regulate chromatin accessibility during steady and transitional cell states. Experiments in mice show that the loss of BRG1 inhibits cellular reprogramming, while studies using human cells demonstrate that the overexpression of BRG1 enhances reprogramming. We hypothesized that the variation of SWI/SNF subunit expression in the human population would contribute to variability in the efficiency of induced pluripotent stem cells (iPSC) reprogramming. To examine the impact of an individual's sex, ancestry, and age on iPSC reprogramming, we created a novel sex and ancestry balanced cohort of 240 iPSC lines derived from human dermal fibroblasts (DF) from 80 heathy donors. We methodically assessed the reprogramming efficiency of each DF line and then quantified the individual and demographic-specific variations in SWI/SNF chromatin remodeling proteins and mRNA expression. We identified BRG1, BAF155, and BAF60a expression as strongly correlating with iPSC reprogramming efficiency. Additionally, we discovered that high efficiency iPSC reprograming is negatively correlated with donor age, positively correlated with African American descent, and uncorrelated with donor sex. These results show the variations in chromatin remodeling protein expression have a strong impact on iPSC reprogramming. Additionally, our cohort is unique in its large size, diversity, and focus on healthy donors. Consequently, this cohort can be a vital tool for researchers seeking to validate observational results from human population studies and perform detailed mechanistic studies in a controlled cell culture environment. Stem Cells 2018;36:1697-1708.
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Affiliation(s)
- Lantz C Mackey
- Epigenetics & Stem Cell Biology Laboratory, Chromatin & Gene Expression Group, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Lois A Annab
- Epigenetics & Stem Cell Biology Laboratory, Chromatin & Gene Expression Group, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Jun Yang
- Epigenetics & Stem Cell Biology Laboratory, Chromatin & Gene Expression Group, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Bhargavi Rao
- Epigenetics & Stem Cell Biology Laboratory, Chromatin & Gene Expression Group, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Grace E Kissling
- Biostatistics & Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Shepard H Schurman
- Clinical Research Branch, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Darlene Dixon
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
| | - Trevor K Archer
- Epigenetics & Stem Cell Biology Laboratory, Chromatin & Gene Expression Group, National Institute of Environmental Health Sciences, Durham, North Carolina, USA
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42
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Alt FW, Schwer B. DNA double-strand breaks as drivers of neural genomic change, function, and disease. DNA Repair (Amst) 2018; 71:158-163. [PMID: 30195640 DOI: 10.1016/j.dnarep.2018.08.019] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Early work from about two decades ago implicated DNA double-strand break (DSB) formation and repair in neuronal development. Findings emerging from recent studies of DSBs in proliferating neural progenitors and in mature, non-dividing neurons suggest important roles of DSBs in brain physiology, aging, cancer, psychiatric and neurodegenerative disorders. We provide an overview of some findings and speculate on what may lie ahead.
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Affiliation(s)
- Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, United States.
| | - Bjoern Schwer
- Department of Neurological Surgery and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94158, United States.
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Morotomi-Yano K, Saito S, Adachi N, Yano KI. Dynamic behavior of DNA topoisomerase IIβ in response to DNA double-strand breaks. Sci Rep 2018; 8:10344. [PMID: 29985428 PMCID: PMC6037730 DOI: 10.1038/s41598-018-28690-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/27/2018] [Indexed: 12/11/2022] Open
Abstract
DNA topoisomerase II (Topo II) is crucial for resolving topological problems of DNA and plays important roles in various cellular processes, such as replication, transcription, and chromosome segregation. Although DNA topology problems may also occur during DNA repair, the possible involvement of Topo II in this process remains to be fully investigated. Here, we show the dynamic behavior of human Topo IIβ in response to DNA double-strand breaks (DSBs), which is the most harmful form of DNA damage. Live cell imaging coupled with site-directed DSB induction by laser microirradiation demonstrated rapid recruitment of EGFP-tagged Topo IIβ to the DSB site. Detergent extraction followed by immunofluorescence showed the tight association of endogenous Topo IIβ with DSB sites. Photobleaching analysis revealed that Topo IIβ is highly mobile in the nucleus. The Topo II catalytic inhibitors ICRF-187 and ICRF-193 reduced the Topo IIβ mobility and thereby prevented Topo IIβ recruitment to DSBs. Furthermore, Topo IIβ knockout cells exhibited increased sensitivity to bleomycin and decreased DSB repair mediated by homologous recombination (HR), implicating the role of Topo IIβ in HR-mediated DSB repair. Taken together, these results highlight a novel aspect of Topo IIβ functions in the cellular response to DSBs.
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Affiliation(s)
- Keiko Morotomi-Yano
- Department of Bioelectrics, Institute of Pulsed Power Science, Kumamoto University, Kumamoto, 860-8555, Japan
| | - Shinta Saito
- Department of Life and Environmental System Science, Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan
| | - Noritaka Adachi
- Department of Life and Environmental System Science, Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan.,Advanced Medical Research Center, Yokohama City University, Yokohama, 236-0004, Japan
| | - Ken-Ichi Yano
- Department of Bioelectrics, Institute of Pulsed Power Science, Kumamoto University, Kumamoto, 860-8555, Japan.
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The Roles of DNA Topoisomerase IIβ in Transcription. Int J Mol Sci 2018; 19:ijms19071917. [PMID: 29966298 PMCID: PMC6073266 DOI: 10.3390/ijms19071917] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/26/2018] [Accepted: 06/27/2018] [Indexed: 12/22/2022] Open
Abstract
Type IIA topoisomerases allow DNA double helical strands to pass through each other by generating transient DNA double strand breaks βDSBs), and in so doing, resolve torsional strain that accumulates during transcription, DNA replication, chromosome condensation, chromosome segregation and recombination. Whereas most eukaryotes possess a single type IIA enzyme, vertebrates possess two distinct type IIA topoisomerases, Topo IIα and Topo IIβ. Although the roles of Topo IIα, especially in the context of chromosome condensation and segregation, have been well-studied, the roles of Topo IIβ are only beginning to be illuminated. This review begins with a summary of the initial studies surrounding the discovery and characterization of Topo IIβ and then focuses on the insights gained from more recent studies that have elaborated important functions for Topo IIβ in transcriptional regulation.
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Hoffman JA, Trotter KW, Ward JM, Archer TK. BRG1 governs glucocorticoid receptor interactions with chromatin and pioneer factors across the genome. eLife 2018; 7:e35073. [PMID: 29792595 PMCID: PMC5967868 DOI: 10.7554/elife.35073] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 04/22/2018] [Indexed: 12/21/2022] Open
Abstract
The Glucocorticoid Receptor (GR) alters transcriptional activity in response to hormones by interacting with chromatin at GR binding sites (GBSs) throughout the genome. Our work in human breast cancer cells identifies three classes of GBSs with distinct epigenetic characteristics and reveals that BRG1 interacts with GBSs prior to hormone exposure. The GBSs pre-occupied by BRG1 are more accessible and transcriptionally active than other GBSs. BRG1 is required for a proper and robust transcriptional hormone response and knockdown of BRG1 blocks recruitment of the pioneer factors FOXA1 and GATA3 to GBSs. Finally, GR interaction with FOXA1 and GATA3 binding sites was restricted to sites pre-bound by BRG1. These findings demonstrate that BRG1 establishes specialized chromatin environments that define multiple classes of GBS. This in turn predicts that GR and other transcriptional activators function via multiple distinct chromatin-based mechanisms to modulate the transcriptional response.
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Affiliation(s)
- Jackson A Hoffman
- Epigenetics and Stem Cell Biology LaboratoryNational Institute of Environmental Health Sciences, National Institutes of HealthNorth CarolinaUnited States
| | - Kevin W Trotter
- Epigenetics and Stem Cell Biology LaboratoryNational Institute of Environmental Health Sciences, National Institutes of HealthNorth CarolinaUnited States
| | - James M Ward
- Integrative BioinformaticsNational Institute of Environmental Health Sciences, National Institutes of HealthNorth CarolinaUnited States
| | - Trevor K Archer
- Epigenetics and Stem Cell Biology LaboratoryNational Institute of Environmental Health Sciences, National Institutes of HealthNorth CarolinaUnited States
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Koh AS, Miller EL, Buenrostro JD, Moskowitz DM, Wang J, Greenleaf WJ, Chang HY, Crabtree GR. Rapid chromatin repression by Aire provides precise control of immune tolerance. Nat Immunol 2018; 19:162-172. [PMID: 29335648 PMCID: PMC6049828 DOI: 10.1038/s41590-017-0032-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/07/2017] [Indexed: 01/23/2023]
Abstract
Aire mediates the expression of tissue-specific antigens in thymic epithelial cells to promote tolerance against self-reactive T lymphocytes. However, the mechanism that allows expression of tissue-specific genes at levels that prevent harm is unknown. Here we show that Brg1 generates accessibility at tissue-specific loci to impose central tolerance. We found that Aire has an intrinsic repressive function that restricts chromatin accessibility and opposes Brg1 across the genome. Aire exerted this repressive influence within minutes after recruitment to chromatin and restrained the amplitude of active transcription. Disease-causing mutations that impair Aire-induced activation also impair the protein's repressive function, which indicates dual roles for Aire. Together, Brg1 and Aire fine-tune the expression of tissue-specific genes at levels that prevent toxicity yet promote immune tolerance.
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Affiliation(s)
- Andrew S Koh
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| | - Erik L Miller
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jason D Buenrostro
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Harvard Society of Fellows, Harvard University, Cambridge, MA, USA
| | - David M Moskowitz
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jing Wang
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - William J Greenleaf
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Chan Zuckerburg Biohub, San Francisco, CA, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA
| | - Gerald R Crabtree
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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Madabhushi R, Kim TK. Emerging themes in neuronal activity-dependent gene expression. Mol Cell Neurosci 2017; 87:27-34. [PMID: 29254824 DOI: 10.1016/j.mcn.2017.11.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/23/2017] [Accepted: 11/08/2017] [Indexed: 12/29/2022] Open
Abstract
In this review, we attempt to discuss emerging themes in the regulation of neuronal activity-regulated genes, focusing primarily on an important subset of immediate-early genes. We first discuss earlier studies that have illuminated the role of cis-acting elements within the promoters of immediate-early genes, the corresponding transcription factors that bind these elements, and the roles of major activity-regulated signaling pathways. However, our emphasis is on new studies that have revealed an important role for epigenetic and topological mechanisms, including enhancer-promoter interactions, enhancer RNAs (eRNAs), and activity-induced DNA breaks, that have emerged as important factors that govern the temporal dynamics of activity-induced gene transcription.
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Affiliation(s)
- Ram Madabhushi
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Tae-Kyung Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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48
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Boulianne B, Feldhahn N. Transcribing malignancy: transcription-associated genomic instability in cancer. Oncogene 2017; 37:971-981. [DOI: 10.1038/onc.2017.402] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/12/2017] [Accepted: 09/12/2017] [Indexed: 12/17/2022]
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Khan FA, Ali SO. Physiological Roles of DNA Double-Strand Breaks. J Nucleic Acids 2017; 2017:6439169. [PMID: 29181194 PMCID: PMC5664317 DOI: 10.1155/2017/6439169] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 09/24/2017] [Indexed: 12/20/2022] Open
Abstract
Genomic integrity is constantly threatened by sources of DNA damage, internal and external alike. Among the most cytotoxic lesions is the DNA double-strand break (DSB) which arises from the cleavage of both strands of the double helix. Cells boast a considerable set of defences to both prevent and repair these breaks and drugs which derail these processes represent an important category of anticancer therapeutics. And yet, bizarrely, cells deploy this very machinery for the intentional and calculated disruption of genomic integrity, harnessing potentially destructive DSBs in delicate genetic transactions. Under tight spatiotemporal regulation, DSBs serve as a tool for genetic modification, widely used across cellular biology to generate diverse functionalities, ranging from the fundamental upkeep of DNA replication, transcription, and the chromatin landscape to the diversification of immunity and the germline. Growing evidence points to a role of aberrant DSB physiology in human disease and an understanding of these processes may both inform the design of new therapeutic strategies and reduce off-target effects of existing drugs. Here, we review the wide-ranging roles of physiological DSBs and the emerging network of their multilateral regulation to consider how the cell is able to harness DNA breaks as a critical biochemical tool.
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Affiliation(s)
- Farhaan A. Khan
- School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge CB2 0SP, UK
| | - Syed O. Ali
- School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge CB2 0SP, UK
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50
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Whirledge S, Cidlowski JA. Glucocorticoids and Reproduction: Traffic Control on the Road to Reproduction. Trends Endocrinol Metab 2017; 28:399-415. [PMID: 28274682 PMCID: PMC5438761 DOI: 10.1016/j.tem.2017.02.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/06/2017] [Accepted: 02/12/2017] [Indexed: 02/06/2023]
Abstract
Glucocorticoids are steroid hormones that regulate diverse cellular functions and are essential to facilitate normal physiology. However, stress-induced levels of glucocorticoids result in several pathologies including profound reproductive dysfunction. Compelling new evidence indicates that glucocorticoids are crucial to the establishment and maintenance of reproductive function. The fertility-promoting or -inhibiting activity of glucocorticoids depends on timing, dose, and glucocorticoid responsiveness within a given tissue, which is mediated by the glucocorticoid receptor (GR). The GR gene and protein are subject to cellular processing, contributing to signaling diversity and providing a mechanism by which both physiological and stress-induced levels of glucocorticoids function in a cell-specific manner. Understanding how glucocorticoids regulate fertility and infertility may lead to novel approaches to the regulation of reproductive function.
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Affiliation(s)
- Shannon Whirledge
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - John A Cidlowski
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, 111 TW Alexander Drive, Research Triangle Park, NC 27709, USA.
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