1
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Detecting G4 unwinding. Methods Enzymol 2022; 672:261-281. [DOI: 10.1016/bs.mie.2022.03.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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2
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Su SG, Li QL, Zhang MF, Zhang PW, Shen H, Zhang CZ. An E2F1/DDX11/EZH2 Positive Feedback Loop Promotes Cell Proliferation in Hepatocellular Carcinoma. Front Oncol 2021; 10:593293. [PMID: 33614480 PMCID: PMC7892623 DOI: 10.3389/fonc.2020.593293] [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: 08/10/2020] [Accepted: 12/15/2020] [Indexed: 12/26/2022] Open
Abstract
Hepatocellular carcinoma (HCC) accounts for one of the leading causes of cancer-related death, and is attributed to the dysregulation of genes involved in genome stability. DDX11, a DNA helicase, has been implicated in rare genetic disease and human cancers. Yet, its clinical value, biological function, and the underlying mechanism in HCC progression are not fully understood. Here, we show that DDX11 is upregulated in HCC and exhibits oncogenic activity via EZH2/p21 signaling. High expression of DDX11 is significantly correlated with poor outcomes of HCC patients in two independent cohorts. DDX11 overexpression increases HCC cell viabilities and colony formation, whereas DDX11 knockdown arrests cells at G1 phase without alteration of p53 expression. Ectopic expression of DDX11 reduces, while depletion of DDX11 induces the expression of p21. Treatment of p21 siRNA markedly attenuates the cell growth suppression caused by DDX11 silence. Further studies reveal that DDX11 interacts with EZH2 in HCC cells to protect it from ubiquitination-mediated protein degradation, consequently resulting in the downregulation of p21. In addition, E2F1 is identified as one of the upstream regulators of DDX11, and forms a positive feedback loop with EZH2 to upregulate DDX11 and facilitate cell proliferation. Collectively, our data suggest DDX11 as a promising prognostic factor and an oncogene in HCC via a E2F1/DDX11/EZH2 positive feedback loop.
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Affiliation(s)
- Shu-Guang Su
- Department of Pathology, The Affiliated Hexian Memorial Hospital of Southern Medical University, Guangzhou, China
| | - Qiu-Li Li
- Department of Head and Neck Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Mei-Fang Zhang
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Peng-Wei Zhang
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Huimin Shen
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Chris Zhiyi Zhang
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou, China
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3
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Brugger C, Zhang C, Suhanovsky MM, Kim DD, Sinclair AN, Lyumkis D, Deaconescu AM. Molecular determinants for dsDNA translocation by the transcription-repair coupling and evolvability factor Mfd. Nat Commun 2020; 11:3740. [PMID: 32719356 PMCID: PMC7385628 DOI: 10.1038/s41467-020-17457-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 07/01/2020] [Indexed: 11/15/2022] Open
Abstract
Mfd couples transcription to nucleotide excision repair, and acts on RNA polymerases when elongation is impeded. Depending on impediment severity, this action results in either transcription termination or elongation rescue, which rely on ATP-dependent Mfd translocation on DNA. Due to its role in antibiotic resistance, Mfd is also emerging as a prime target for developing anti-evolution drugs. Here we report the structure of DNA-bound Mfd, which reveals large DNA-induced structural changes that are linked to the active site via ATPase motif VI. These changes relieve autoinhibitory contacts between the N- and C-termini and unmask UvrA recognition determinants. We also demonstrate that translocation relies on a threonine in motif Ic, widely conserved in translocases, and a family-specific histidine near motif IVa, reminiscent of the “arginine clamp” of RNA helicases. Thus, Mfd employs a mode of DNA recognition that at its core is common to ss/ds translocases that act on DNA or RNA. Transcription-repair coupling factors (TRCFs) are large ATPases that mediate the preferential repair of the transcribed DNA strand. Here the authors reveal the cryo-EM structure of DNA-bound Mfd, the bacterial TRCF, and provide molecular insights into its mode of action.
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Affiliation(s)
- Christiane Brugger
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Cheng Zhang
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92093, USA
| | - Margaret M Suhanovsky
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - David D Kim
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Amy N Sinclair
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92093, USA.,Department of Computational and Structural Biology, The Scripps Research Institute, La Jolla, CA, 92093, USA
| | - Alexandra M Deaconescu
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02903, USA.
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4
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DNA Helicases as Safekeepers of Genome Stability in Plants. Genes (Basel) 2019; 10:genes10121028. [PMID: 31835565 PMCID: PMC6947026 DOI: 10.3390/genes10121028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 02/07/2023] Open
Abstract
Genetic information of all organisms is coded in double-stranded DNA. DNA helicases are essential for unwinding this double strand when it comes to replication, repair or transcription of genetic information. In this review, we will focus on what is known about a variety of DNA helicases that are required to ensure genome stability in plants. Due to their sessile lifestyle, plants are especially exposed to harmful environmental factors. Moreover, many crop plants have large and highly repetitive genomes, making them absolutely dependent on the correct interplay of DNA helicases for safeguarding their stability. Although basic features of a number of these enzymes are conserved between plants and other eukaryotes, a more detailed analysis shows surprising peculiarities, partly also between different plant species. This is additionally of high relevance for plant breeding as a number of these helicases are also involved in crossover control during meiosis and influence the outcome of different approaches of CRISPR/Cas based plant genome engineering. Thus, gaining knowledge about plant helicases, their interplay, as well as the manipulation of their pathways, possesses the potential for improving agriculture. In the long run, this might even help us cope with the increasing obstacles of climate change threatening food security in completely new ways.
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5
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Khodour Y, Kaguni LS, Stiban J. Iron-sulfur clusters in nucleic acid metabolism: Varying roles of ancient cofactors. Enzymes 2019; 45:225-256. [PMID: 31627878 DOI: 10.1016/bs.enz.2019.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Despite their relative simplicity, iron-sulfur clusters have been omnipresent as cofactors in myriad cellular processes such as oxidative phosphorylation and other respiratory pathways. Recent research advances confirm the presence of different clusters in enzymes involved in nucleic acid metabolism. Iron-sulfur clusters can therefore be considered hallmarks of cellular metabolism. Helicases, nucleases, glycosylases, DNA polymerases and transcription factors, among others, incorporate various types of clusters that serve differing roles. In this chapter, we review our current understanding of the identity and functions of iron-sulfur clusters in DNA and RNA metabolizing enzymes, highlighting their importance as regulators of cellular function.
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Affiliation(s)
- Yara Khodour
- Department of Biology and Biochemistry, Birzeit University, West Bank, Palestine
| | - Laurie S Kaguni
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Johnny Stiban
- Department of Biology and Biochemistry, Birzeit University, West Bank, Palestine.
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6
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Bonache S, Esteban I, Moles-Fernández A, Tenés A, Duran-Lozano L, Montalban G, Bach V, Carrasco E, Gadea N, López-Fernández A, Torres-Esquius S, Mancuso F, Caratú G, Vivancos A, Tuset N, Balmaña J, Gutiérrez-Enríquez S, Diez O. Multigene panel testing beyond BRCA1/2 in breast/ovarian cancer Spanish families and clinical actionability of findings. J Cancer Res Clin Oncol 2018; 144:2495-2513. [PMID: 30306255 DOI: 10.1007/s00432-018-2763-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/01/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE Few and small studies have been reported about multigene testing usage by massively parallel sequencing in European cancer families. There is an open debate about what genes should be tested, and the actionability of some included genes is under research. METHODS We investigated a panel of 34 known high/moderate-risk cancer genes, including 16 related to breast or ovarian cancer (BC/OC) genes, and 63 candidate genes to BC/OC in 192 clinically suspicious of hereditary breast/ovarian cancer (HBOC) Spanish families without pathogenic variants in BRCA1 or BRCA2 (BRCA1/2). RESULTS We identified 16 patients who carried a high- or moderate-risk pathogenic variant in eight genes: 4 PALB2, 3 ATM, 2 RAD51D, 2 TP53, 2 APC, 1 BRIP1, 1 PTEN and 1 PMS2. These findings led to increased surveillance or prevention options in 12 patients and predictive testing in their family members. We detected 383 unique variants of uncertain significance in known cancer genes, of which 35 were prioritized in silico. Eighteen loss-of-function variants were detected in candidate BC/OC genes in 17 patients (1 BARD1, 1 ERCC3, 1 ERCC5, 2 FANCE, 1 FANCI, 2 FANCL, 1 FANCM, 1 MCPH1, 1 PPM1D, 2 RBBP8, 3 RECQL4 and 1 with SLX4 and XRCC2), three of which also carry pathogenic variants in known cancer genes. CONCLUSIONS Eight percent of the BRCA1/2 negative patients carry pathogenic variants in other actionable genes. The multigene panel usage improves the diagnostic yield in HBOC testing and it is an effective tool to identify potentially new candidate genes.
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Affiliation(s)
- Sandra Bonache
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain
| | - Irene Esteban
- High Risk and Cancer Prevention Group, VHIO, Barcelona, Spain
- Genetics and Microbiology Department, Universitat Autònoma de Barcelona, Campus UAB, Bellaterra, Spain
| | - Alejandro Moles-Fernández
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain
| | - Anna Tenés
- Area of Clinical and Molecular Genetics, University Hospital of Vall d'Hebron, Barcelona, Spain
| | - Laura Duran-Lozano
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain
| | - Gemma Montalban
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain
| | - Vanessa Bach
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain
| | - Estela Carrasco
- High Risk and Cancer Prevention Group, VHIO, Barcelona, Spain
| | - Neus Gadea
- High Risk and Cancer Prevention Group, VHIO, Barcelona, Spain
- Medical Oncology Department, University Hospital of Vall d'Hebron, Barcelona, Spain
| | | | | | - Francesco Mancuso
- Cancer Genomics Group, Vall d'Hebron Institute of Oncology, VHIO, Barcelona, Spain
| | - Ginevra Caratú
- Cancer Genomics Group, Vall d'Hebron Institute of Oncology, VHIO, Barcelona, Spain
| | - Ana Vivancos
- Cancer Genomics Group, Vall d'Hebron Institute of Oncology, VHIO, Barcelona, Spain
| | - Noemí Tuset
- Medical Oncology Department, Hospital Universitari Arnau de Vilanova, Lleida, Spain
| | - Judith Balmaña
- High Risk and Cancer Prevention Group, VHIO, Barcelona, Spain
- Medical Oncology Department, University Hospital of Vall d'Hebron, Barcelona, Spain
| | - Sara Gutiérrez-Enríquez
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain.
| | - Orland Diez
- Oncogenetics Group, Vall d'Hebron Institute of Oncology-VHIO, Lab 2.02A, CELLEX CENTER, c/Natzaret, 115-117, 08035, Barcelona, Catalonia, Spain.
- Area of Clinical and Molecular Genetics, University Hospital of Vall d'Hebron, Barcelona, Spain.
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7
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UPF1-like helicase grip on nucleic acids dictates processivity. Nat Commun 2018; 9:3752. [PMID: 30218034 PMCID: PMC6138625 DOI: 10.1038/s41467-018-06313-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 08/29/2018] [Indexed: 12/25/2022] Open
Abstract
Helicases are molecular engines which translocate along nucleic acids (NA) to unwind double-strands or remodel NA–protein complexes. While they have an essential role in genome structure and expression, the rules dictating their processivity remain elusive. Here, we developed single-molecule methods to investigate helicase binding lifetime on DNA. We found that UPF1, a highly processive helicase central to nonsense-mediated mRNA decay (NMD), tightly holds onto NA, allowing long lasting action. Conversely, the structurally similar IGHMBP2 helicase has a short residence time. UPF1 mutants with variable grip on DNA show that grip tightness dictates helicase residence time and processivity. In addition, we discovered via functional studies that a decrease in UPF1 grip impairs NMD efficiency in vivo. Finally, we propose a three-state model with bound, sliding and unbound molecular clips, that can accurately predict the modulation of helicase processivity. UPF1 is a highly processive helicase that plays an essential role in nonsense-mediated mRNA decay. Here the authors use single molecule binding assays to establish a functionally important relationship between helicase grip to nucleic acids, binding lifetime and the duration of translocation.
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8
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Seo YS, Kang YH. The Human Replicative Helicase, the CMG Complex, as a Target for Anti-cancer Therapy. Front Mol Biosci 2018; 5:26. [PMID: 29651420 PMCID: PMC5885281 DOI: 10.3389/fmolb.2018.00026] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 03/12/2018] [Indexed: 12/14/2022] Open
Abstract
DNA helicases unwind or rearrange duplex DNA during replication, recombination and repair. Helicases of many pathogenic organisms such as viruses, bacteria, and protozoa have been studied as potential therapeutic targets to treat infectious diseases, and human DNA helicases as potential targets for anti-cancer therapy. DNA replication machineries perform essential tasks duplicating genome in every cell cycle, and one of the important functions of these machineries are played by DNA helicases. Replicative helicases are usually multi-subunit protein complexes, and the minimal complex active as eukaryotic replicative helicase is composed of 11 subunits, requiring a functional assembly of two subcomplexes and one protein. The hetero-hexameric MCM2-7 helicase is activated by forming a complex with Cdc45 and the hetero-tetrameric GINS complex; the Cdc45-Mcm2-7-GINS (CMG) complex. The CMG complex can be a potential target for a treatment of cancer and the feasibility of this replicative helicase as a therapeutic target has been tested recently. Several different strategies have been implemented and are under active investigations to interfere with helicase activity of the CMG complex. This review focuses on the molecular function of the CMG helicase during DNA replication and its relevance to cancers based on data published in the literature. In addition, current efforts made to identify small molecules inhibiting the CMG helicase to develop anti-cancer therapeutic strategies were summarized, with new perspectives to advance the discovery of the CMG-targeting drugs.
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Affiliation(s)
- Yeon-Soo Seo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Young-Hoon Kang
- Core Protein Resources Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
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9
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Wachnowsky C, Fidai I, Cowan JA. Iron-sulfur cluster biosynthesis and trafficking - impact on human disease conditions. Metallomics 2018; 10:9-29. [PMID: 29019354 PMCID: PMC5783746 DOI: 10.1039/c7mt00180k] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Iron-sulfur clusters (Fe-S) are one of the most ancient, ubiquitous and versatile classes of metal cofactors found in nature. Proteins that contain Fe-S clusters constitute one of the largest families of proteins, with varied functions that include electron transport, regulation of gene expression, substrate binding and activation, radical generation, and, more recently discovered, DNA repair. Research during the past two decades has shown that mitochondria are central to the biogenesis of Fe-S clusters in eukaryotic cells via a conserved cluster assembly machinery (ISC assembly machinery) that also controls the synthesis of Fe-S clusters of cytosolic and nuclear proteins. Several key steps for synthesis and trafficking have been determined for mitochondrial Fe-S clusters, as well as the cytosol (CIA - cytosolic iron-sulfur protein assembly), but detailed mechanisms of cluster biosynthesis, transport, and exchange are not well established. Genetic mutations and the instability of certain steps in the biosynthesis and maturation of mitochondrial, cytosolic and nuclear Fe-S cluster proteins affects overall cellular iron homeostasis and can lead to severe metabolic, systemic, neurological and hematological diseases, often resulting in fatality. In this review we briefly summarize the current molecular understanding of both mitochondrial ISC and CIA assembly machineries, and present a comprehensive overview of various associated inborn human disease states.
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Affiliation(s)
- C Wachnowsky
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
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10
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Stiban J, So M, Kaguni LS. Iron-Sulfur Clusters in Mitochondrial Metabolism: Multifaceted Roles of a Simple Cofactor. BIOCHEMISTRY (MOSCOW) 2017; 81:1066-1080. [PMID: 27908232 DOI: 10.1134/s0006297916100059] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron-sulfur metabolism is essential for cellular function and is a key process in mitochondria. In this review, we focus on the structure and assembly of mitochondrial iron-sulfur clusters and their roles in various metabolic processes that occur in mitochondria. Iron-sulfur clusters are crucial in mitochondrial respiration, in which they are required for the assembly, stability, and function of respiratory complexes I, II, and III. They also serve important functions in the citric acid cycle, DNA metabolism, and apoptosis. Whereas the identification of iron-sulfur containing proteins and their roles in numerous aspects of cellular function has been a long-standing research area, that in mitochondria is comparatively recent, and it is likely that their roles within mitochondria have been only partially revealed. We review the status of the field and provide examples of other cellular iron-sulfur proteins to highlight their multifarious roles.
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Affiliation(s)
- Johnny Stiban
- Birzeit University, Department of Biology and Biochemistry, West Bank Birzeit, 627, Palestine.
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11
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DNA damage repair in breast cancer and its therapeutic implications. Pathology 2016; 49:156-165. [PMID: 28034453 DOI: 10.1016/j.pathol.2016.11.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/06/2016] [Accepted: 11/02/2016] [Indexed: 11/23/2022]
Abstract
The DNA damage response (DDR) involves the activation of numerous cellular activities that repair DNA lesions and maintain genomic integrity, and is critical in preventing tumorigenesis. Inherited or acquired mutations in specific genes involved in the DNA damage response, for example the breast cancer susceptibility genes 1/2 (BRCA1/2), phosphatase and tensin homolog (PTEN) and P53 are associated with various subtypes of breast cancer. Such changes can render breast cancer cells particularly sensitive to specific DNA damage response inhibitors, for example BRCA1/2 germline mutated cells are sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. The aims of this review are to discuss specific DNA damage response defects in breast cancer and to present the current stage of development of various DDR inhibitors (namely PARP, ATM/ATR, DNA-PK, PARG, RECQL5, FEN1 and APE1) for breast cancer mono- and combination therapy.
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12
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Mojumdar A, De March M, Marino F, Onesti S. The Human RecQ4 Helicase Contains a Functional RecQ C-terminal Region (RQC) That Is Essential for Activity. J Biol Chem 2016; 292:4176-4184. [PMID: 27998982 DOI: 10.1074/jbc.m116.767954] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/18/2016] [Indexed: 11/06/2022] Open
Abstract
RecQ helicases are essential in the maintenance of genome stability. Five paralogues (RecQ1, Bloom, Werner, RecQ4, and RecQ5) are found in human cells, with distinct but overlapping roles. Mutations in human RecQ4 give rise to three distinct genetic disorders (Rothmund-Thomson, RAPADILINO, and Baller-Gerold syndromes), characterized by genetic instability, growth deficiency, and predisposition to cancer. Previous studies suggested that RecQ4 was unique because it did not seem to contain a RecQ C-terminal region (RQC) found in the other RecQ paralogues; such a region consists of a zinc domain and a winged helix domain and plays an important role in enzyme activity. However, our recent bioinformatic analysis identified in RecQ4 a putative RQC. To experimentally confirm this hypothesis, we report the purification and characterization of the catalytic core of human RecQ4. Inductively coupled plasma-atomic emission spectrometry detected the unusual presence of two zinc clusters within the zinc domain, consistent with the bioinformatic prediction. Analysis of site-directed mutants, targeting key RQC residues (putative zinc ligands and the aromatic residue predicted to be at the tip of the winged helix β-hairpin), showed a decrease in DNA binding, unwinding, and annealing, as expected for a functional RQC domain. Low resolution structural information obtained by small angle X-ray scattering data suggests that RecQ4 interacts with DNA in a manner similar to RecQ1, whereas the winged helix domain may assume alternative conformations, as seen in the bacterial enzymes. These combined results experimentally confirm the presence of a functional RQC domain in human RecQ4.
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Affiliation(s)
- Aditya Mojumdar
- From the Structural Biology Laboratory, Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy and.,the Dipartimento di Scienze della Vita, Università degli Studi di Trieste, 34127 Trieste, Italy
| | - Matteo De March
- From the Structural Biology Laboratory, Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy and
| | - Francesca Marino
- From the Structural Biology Laboratory, Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy and
| | - Silvia Onesti
- From the Structural Biology Laboratory, Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy and
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13
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Kalejaiye A, Giri N, Brewer CC, Zalewski CK, King KA, Adams CD, Rosenberg PS, Kim HJ, Alter BP. Otologic manifestations of Fanconi anemia and other inherited bone marrow failure syndromes. Pediatr Blood Cancer 2016; 63:2139-2145. [PMID: 27428025 DOI: 10.1002/pbc.26155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/07/2016] [Accepted: 06/28/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND The inherited bone marrow failure syndromes (IBMFSs) are diverse disorders with syndrome-specific features; their otologic and audiologic manifestations have not been well described. Our objective was to characterize these in patients with Fanconi anemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anemia (DBA), and Shwachman-Diamond syndrome (SDS), and to determine the association between physical findings and hearing loss. METHODS Patients with an IBMFS underwent comprehensive clinical and laboratory evaluations and testing for syndrome-specific gene mutations. Hearing loss was measured by pure tone audiometry and otologic abnormalities by otomicroscopy. RESULTS Patients included 33 with FA, 37 with DC, 32 with DBA, and nine with SDS. Hearing loss was most frequent in patients with FA (45%) and DBA (14%). The most common type of hearing loss in FA was conductive (65%). Absent or hypoplastic radius, noted in 21% of the patients with FA, was associated with hearing loss in all cases. Otomicroscopy was abnormal in 66% of patients with FA. Characteristic ear abnormalities included small tympanic membrane (66%), malformed malleus (57%), aberrant tympanic bony island (48%), narrow external auditory canal (EAC) (32%), and abnormal course of chorda tympani (34%). Ear malformations were almost always associated with hearing loss. Hearing loss was rare in patients with DC and SDS. CONCLUSIONS FA is the major IBMFS with associated hearing loss, which is most commonly conductive. Radial hypoplasia or aplasia and characteristic congenital ear malformations are associated with hearing loss in patients with FA. Recognition of these syndrome-specific abnormalities should lead to earlier management of hearing loss.
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Affiliation(s)
| | - Neelam Giri
- National Cancer Institute, National Institutes of Health, Rockville, Maryland.
| | - Carmen C Brewer
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Christopher K Zalewski
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Kelly A King
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Charleen D Adams
- University of Washington School of Public Health, Seattle, Washington
| | - Philip S Rosenberg
- National Cancer Institute, National Institutes of Health, Rockville, Maryland
| | - H Jeffrey Kim
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland.,Medstar Georgetown University Hospital, Washington, District of Columbia
| | - Blanche P Alter
- National Cancer Institute, National Institutes of Health, Rockville, Maryland
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14
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The excluded DNA strand is SEW important for hexameric helicase unwinding. Methods 2016; 108:79-91. [DOI: 10.1016/j.ymeth.2016.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 02/04/2023] Open
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15
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da Costa JP, Vitorino R, Silva GM, Vogel C, Duarte AC, Rocha-Santos T. A synopsis on aging-Theories, mechanisms and future prospects. Ageing Res Rev 2016; 29:90-112. [PMID: 27353257 PMCID: PMC5991498 DOI: 10.1016/j.arr.2016.06.005] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/23/2016] [Accepted: 06/23/2016] [Indexed: 12/31/2022]
Abstract
Answering the question as to why we age is tantamount to answering the question of what is life itself. There are countless theories as to why and how we age, but, until recently, the very definition of aging - senescence - was still uncertain. Here, we summarize the main views of the different models of senescence, with a special emphasis on the biochemical processes that accompany aging. Though inherently complex, aging is characterized by numerous changes that take place at different levels of the biological hierarchy. We therefore explore some of the most relevant changes that take place during aging and, finally, we overview the current status of emergent aging therapies and what the future holds for this field of research. From this multi-dimensional approach, it becomes clear that an integrative approach that couples aging research with systems biology, capable of providing novel insights into how and why we age, is necessary.
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Affiliation(s)
- João Pinto da Costa
- CESAM and Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
| | - Rui Vitorino
- Department of Medical Sciences, Institute for Biomedicine-iBiMED, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal; Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Gustavo M Silva
- Department of Biology, Center for Genomics and Systems Biology, NY, NY 10003, USA
| | - Christine Vogel
- Department of Biology, Center for Genomics and Systems Biology, NY, NY 10003, USA
| | - Armando C Duarte
- CESAM and Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
| | - Teresa Rocha-Santos
- CESAM and Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal
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16
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Welcsh P, Kehrli K, Lazarchuk P, Ladiges W, Sidorova J. Application of the microfluidic-assisted replication track analysis to measure DNA repair in human and mouse cells. Methods 2016; 108:99-110. [PMID: 27130890 DOI: 10.1016/j.ymeth.2016.04.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/19/2016] [Accepted: 04/25/2016] [Indexed: 11/25/2022] Open
Abstract
Functional studies of the roles that DNA helicases play in human cells have benefited immensely from DNA fiber (or single molecule) technologies, which enable us to discern minute differences in behaviors of individual replication forks in genomic DNA in vivo. DNA fiber technologies are a group of methods that use different approaches to unravel and stretch genomic DNA to its contour length, and display it on a glass surface in order to immuno-stain nucleoside analog incorporation into DNA to reveal tracks (or tracts) of replication. We have previously adopted a microfluidic approach to DNA stretching and used it to analyze DNA replication. This method was introduced under the moniker maRTA or microfluidic-assisted Replication Track Analysis, and we have since used it to analyze roles of the RECQ helicases WRN and BLM, and other proteins in normal and perturbed replication. Here we describe a novel application of maRTA to detect and measure repair of DNA damage produced by three different agents relevant to etiology or therapy of cancer: methyl-methanesulfonate, UV irradiation, and mitomycin C. Moreover, we demonstrate the utility of this method by analyzing DNA repair in cells with reduced levels of WRN or of the base excision repair protein XRCC1.
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Affiliation(s)
- Piri Welcsh
- Department of Pathology, Box 357705, University of Washington, 1959 NE Pacific St., Seattle, WA 98195-7705, USA
| | - Keffy Kehrli
- Department of Pathology, Box 357705, University of Washington, 1959 NE Pacific St., Seattle, WA 98195-7705, USA
| | - Pavlo Lazarchuk
- Department of Pathology, Box 357705, University of Washington, 1959 NE Pacific St., Seattle, WA 98195-7705, USA
| | - Warren Ladiges
- Department of Comparative Medicine, Box 357340, University of Washington, 1959 NE Pacific St., Seattle, WA 98195-7340, USA
| | - Julia Sidorova
- Department of Pathology, Box 357705, University of Washington, 1959 NE Pacific St., Seattle, WA 98195-7705, USA.
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17
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Py B, Barras F. [Iron and sulfur in proteins. How does the cell build Fe-S clusters, cofactors essential for life?]. Med Sci (Paris) 2014; 30:1110-22. [PMID: 25537041 DOI: 10.1051/medsci/20143012014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Iron-sulfur clusters (Fe-S) are ubiquitous cofactors present in numerous proteins of most living organisms. By way of an example, the E. coli bacterium synthesizes more that 130 different types of Fe-S proteins. Fe-S proteins are involved in a great diversity of biological processes, ranging from respiration, photosynthesis, central metabolism, to genetic expression and genomic stability. Proteins can acquire spontaneously Fe-S clusters in vitro, but in vivo, dedicated molecular machineries are necessary. Dysfunction of these machineries alters cellular capacities leading to lethality in bacteria and severe pathologies in humans. In this review we will describe how cells make Fe-S clusters and deliver them to clients proteins. The importance of Fe-S clusters homeostasis will be illustrated by reporting a list of cellular dysfunctions associated with mutations altering either Fe-S proteins or Fe-S biogenesis machineries.
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Affiliation(s)
- Béatrice Py
- Laboratoire de Chimie Bactérienne, UMR 7283 CNRS-Aix-Marseille Université, Institut de Microbiologie de la Méditerranée, 31, chemin Joseph Aiguier, 13009 Marseille, France
| | - Frédéric Barras
- Laboratoire de Chimie Bactérienne, UMR 7283 CNRS-Aix-Marseille Université, Institut de Microbiologie de la Méditerranée, 31, chemin Joseph Aiguier, 13009 Marseille, France
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18
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Basile G, Leuzzi G, Pichierri P, Franchitto A. Checkpoint-dependent and independent roles of the Werner syndrome protein in preserving genome integrity in response to mild replication stress. Nucleic Acids Res 2014; 42:12628-39. [PMID: 25352544 PMCID: PMC4227752 DOI: 10.1093/nar/gku1022] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Werner syndrome (WS) is a human chromosomal instability disorder associated with cancer predisposition and caused by mutations in the WRN gene. WRN helicase activity is crucial in limiting breakage at common fragile sites (CFS), which are the preferential targets of genome instability in precancerous lesions. However, the precise function of WRN in response to mild replication stress, like that commonly used to induce breaks at CFS, is still missing. Here, we establish that WRN plays a role in mediating CHK1 activation under moderate replication stress. We provide evidence that phosphorylation of CHK1 relies on the ATR-mediated phosphorylation of WRN, but not on WRN helicase activity. Analysis of replication fork dynamics shows that loss of WRN checkpoint mediator function as well as of WRN helicase activity hamper replication fork progression, and lead to new origin activation to allow recovery from replication slowing upon replication stress. Furthermore, bypass of WRN checkpoint mediator function through overexpression of a phospho-mimic form of CHK1 restores fork progression and chromosome stability to the wild-type levels. Together, these findings are the first demonstration that WRN regulates the ATR-checkpoint activation upon mild replication stress, preventing chromosome fragility.
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Affiliation(s)
- Giorgia Basile
- Section of Molecular Epidemiology, Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy Genome Stability Group, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy
| | - Giuseppe Leuzzi
- Section of Molecular Epidemiology, Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy Genome Stability Group, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy
| | - Pietro Pichierri
- Genome Stability Group, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy Section of Experimental and Computational Carcinogenesis, Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy
| | - Annapaola Franchitto
- Section of Molecular Epidemiology, Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy Genome Stability Group, Istituto Superiore di Sanità, Viale Regina Elena, 299-00161 Rome, Italy
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19
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Beuck C, Weinhold E. Reversibly locked thionucleobase pairs in DNA to study base flipping enzymes. Beilstein J Org Chem 2014; 10:2293-306. [PMID: 25298797 PMCID: PMC4187101 DOI: 10.3762/bjoc.10.239] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/28/2014] [Indexed: 12/16/2022] Open
Abstract
Covalently interstrand cross-linked DNA is an interesting tool to study DNA binding proteins that locally open up the DNA duplex by flipping single bases out of the DNA helix or melting whole stretches of base pairs to perform their function. The ideal DNA cross-link to study protein–DNA interactions should be specific and easy to synthesize, be stable during protein binding experiments, have a short covalent linker to avoid steric hindrance of protein binding, and should be available as a mimic for both A/T and G/C base pairs to cover all possible binding specificities. Several covalent interstrand cross-links have been described in the literature, but most of them fall short of at least one of the above criteria. We developed an efficient method to site-specifically and reversibly cross-link thionucleoside base pairs in synthetic duplex oligodeoxynucleotides by bisalkylation with 1,2-diiodoethane resulting in an ethylene-bridged base pair. Both linked A/T and G/C base pair analogs can conveniently be prepared which allows studying any base pair-opening enzyme regardless of its sequence specificity. The cross-link is stable in the absence of reducing agents but the linker can be quickly and tracelessly removed by the addition of thiol reagents like dithiothreitol. This property makes the cross-linking reaction fully reversible and allows for a switching of the linked base pair from locked to unlocked during biochemical experiments. Using the DNA methyltransferase from Thermus aquaticus (M.TaqI) as example, we demonstrate that the presented cross-linked DNA with an ethylene-linked A/T base pair analog at the target position is a useful tool to determine the base-flipping equilibrium constant of a base-flipping enzyme which lies mostly on the extrahelical side for M.TaqI.
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Affiliation(s)
- Christine Beuck
- Department of Structural & Medicinal Biochemistry, University of Duisburg-Essen, Universitätsstr. 2-5, D-45141 Essen, Germany
| | - Elmar Weinhold
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52056 Aachen, Germany
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20
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Aarattuthodiyil S, Byrd AK, Raney KD. Simultaneous binding to the tracking strand, displaced strand and the duplex of a DNA fork enhances unwinding by Dda helicase. Nucleic Acids Res 2014; 42:11707-20. [PMID: 25249618 PMCID: PMC4191417 DOI: 10.1093/nar/gku845] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Interactions between helicases and the tracking strand of a DNA substrate are well-characterized; however, the role of the displaced strand is a less understood characteristic of DNA unwinding. Dda helicase exhibited greater processivity when unwinding a DNA fork compared to a ss/ds DNA junction substrate. The lag phase in the unwinding progress curve was reduced for the forked DNA compared to the ss/ds junction. Fewer kinetic steps were required to unwind the fork compared to the ss/ds junction, suggesting that binding to the fork leads to disruption of the duplex. DNA footprinting confirmed that interaction of Dda with a fork leads to two base pairs being disrupted whereas no disruption of base pairing was observed with the ss/ds junction. Neutralization of the phosphodiester backbone resulted in a DNA-footprinting pattern similar to that observed with the ss/ds junction, consistent with disruption of the interaction between Dda and the displaced strand. Several basic residues in the 1A domain which were previously proposed to bind to the incoming duplex DNA were replaced with alanines, resulting in apparent loss of interaction with the duplex. Taken together, these results suggest that Dda interaction with the tracking strand, displaced strand and duplex coordinates DNA unwinding.
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Affiliation(s)
- Suja Aarattuthodiyil
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Alicia K Byrd
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Kevin D Raney
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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21
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Spies M. Two steps forward, one step back: determining XPD helicase mechanism by single-molecule fluorescence and high-resolution optical tweezers. DNA Repair (Amst) 2014; 20:58-70. [PMID: 24560558 DOI: 10.1016/j.dnarep.2014.01.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/31/2013] [Accepted: 01/13/2014] [Indexed: 11/17/2022]
Abstract
XPD-like helicases constitute a prominent DNA helicase family critical for many aspects of genome maintenance. These enzymes share a unique structural feature, an auxiliary domain stabilized by an iron-sulphur (FeS) cluster, and a 5'-3' polarity of DNA translocation and duplex unwinding. Biochemical analyses alongside two single-molecule approaches, total internal reflection fluorescence microscopy and high-resolution optical tweezers, have shown how the unique structural features of XPD helicase and its specific patterns of substrate interactions tune the helicase for its specific cellular function and shape its molecular mechanism. The FeS domain forms a duplex separation wedge and contributes to an extended DNA binding site. Interactions within this site position the helicase in an orientation to unwind the duplex, control the helicase rate, and verify the integrity of the translocating strand. Consistent with its cellular role, processivity of XPD is limited and is defined by an idiosyncratic stepping kinetics. DNA duplex separation occurs in single base pair steps punctuated by frequent backward steps and conformational rearrangements of the protein-DNA complex. As such, the helicase in isolation mainly stabilizes spontaneous base pair opening and exhibits a limited ability to unwind stable DNA duplexes. The presence of a cognate ssDNA binding protein converts XPD into a vigorous helicase by destabilizing the upstream dsDNA as well as by trapping the unwound strands. Remarkably, the two proteins can co-exist on the same DNA strand without competing for binding. The current model of the XPD unwinding mechanism will be discussed along with possible modifications to this mechanism by the helicase interacting partners and unique features of such bio-medically important XPD-like helicases as FANCJ (BACH1), RTEL1 and CHLR1 (DDX11).
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Affiliation(s)
- Maria Spies
- Department of Biochemistry, University of Iowa Carver College of Medicine, IA 52242, United States.
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22
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Radons J. Inflammatory stress and sarcomagenesis: a vicious interplay. Cell Stress Chaperones 2014; 19:1-13. [PMID: 24046208 PMCID: PMC3857425 DOI: 10.1007/s12192-013-0449-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/15/2013] [Accepted: 07/17/2013] [Indexed: 12/15/2022] Open
Abstract
Chronic inflammation represents one of the hallmarks of cancer, but its role in sarcomagenesis has long been overlooked. Sarcomas are a rare and heterogeneous group of tumors of mesenchymal origin accounting for less than 1 % of cancers in adults but 21 % of cancers in the pediatric population. Sarcomas are associated with bad prognosis, and their management requires a multidisciplinary team approach. Several lines of evidence indicate that inflammation has been implicated in sarcomagenesis leading to the activation of the key transcription factors HIF-1, NF- κB, and STAT-3 involved in a complex inflammatory network. In the past years, an increasing number of new targets have been identified in the treatment of sarcomas leading to the development of new drugs that aim to interrupt the vicious connection between inflammation and sarcomagenesis. This article makes a brief overview of preclinical and clinical evidence of the molecular pathways involved in the inflammatory stress response in sarcomagenesis and the most targeted therapies.
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Affiliation(s)
- Jürgen Radons
- multimmune GmbH c/o Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Straße 22, 81675, Munich, Germany,
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23
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Radons J. The role of inflammation in sarcoma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 816:259-313. [PMID: 24818727 DOI: 10.1007/978-3-0348-0837-8_11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sarcomas encompass a heterogenous group of tumors with diverse pathologically and clinically overlapping features. It is a rarely curable disease, and their management requires a multidisciplinary team approach. Chronic inflammation has emerged as one of the hallmarks of tumors including sarcomas. Classical inflammation-associated sarcomas comprise the inflammatory malignant fibrous histiocytoma and Kaposi sarcoma. The identification of specific chromosomal translocations and important intracellular signaling pathways such as Ras/Raf/MAPK, insulin-like growth factor, PI3K/AKT/mTOR, sonic hedgehog and Notch together with the increasing knowledge of angiogenesis has led to development of targeted therapies that aim to interrupt these pathways. Innovative agents like oncolytic viruses opened the way to design new therapeutic options with encouraging findings. Preclinical evidence also highlights the therapeutic potential of anti-inflammatory nutraceuticals as they can inhibit multiple pathways while being less toxic. This chapter gives an overview of actual therapeutic standards, newest evidence-based studies and exciting options for targeted therapies in sarcomas.
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Affiliation(s)
- Jürgen Radons
- Department of Radiotherapy and Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Straße 22, 81675, Munich, Germany,
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24
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Shadrick WR, Ndjomou J, Kolli R, Mukherjee S, Hanson AM, Frick DN. Discovering new medicines targeting helicases: challenges and recent progress. ACTA ACUST UNITED AC 2013; 18:761-81. [PMID: 23536547 PMCID: PMC4427233 DOI: 10.1177/1087057113482586] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Helicases are ubiquitous motor proteins that separate and/or rearrange nucleic acid duplexes in reactions fueled by adenosine triphosphate (ATP) hydrolysis. Helicases encoded by bacteria, viruses, and human cells are widely studied targets for new antiviral, antibiotic, and anticancer drugs. This review summarizes the biochemistry of frequently targeted helicases. These proteins include viral enzymes from herpes simplex virus, papillomaviruses, polyomaviruses, coronaviruses, the hepatitis C virus, and various flaviviruses. Bacterial targets examined include DnaB-like and RecBCD-like helicases. The human DEAD-box protein DDX3 is the cellular antiviral target discussed, and cellular anticancer drug targets discussed are the human RecQ-like helicases and eIF4A. We also review assays used for helicase inhibitor discovery and the most promising and common helicase inhibitor chemotypes, such as nucleotide analogues, polyphenyls, metal ion chelators, flavones, polycyclic aromatic polymers, coumarins, and various DNA binding pharmacophores. Also discussed are common complications encountered while searching for potent helicase inhibitors and possible solutions for these problems.
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Affiliation(s)
- William R Shadrick
- Department of Chemistry & Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA
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