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Wang B, Najmudin S, Pan XS, Mykhaylyk V, Orr C, Wagner A, Govada L, Chayen NE, Fisher LM, Sanderson MR. Experimental localization of metal-binding sites reveals the role of metal ions in type II DNA topoisomerases. Proc Natl Acad Sci U S A 2024; 121:e2413357121. [PMID: 39361644 DOI: 10.1073/pnas.2413357121] [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: 07/05/2024] [Accepted: 08/27/2024] [Indexed: 10/05/2024] Open
Abstract
Metal ions have important roles in supporting the catalytic activity of DNA-regulating enzymes such as topoisomerases (topos). Bacterial type II topos, gyrases and topo IV, are primary drug targets for fluoroquinolones, a class of clinically relevant antibacterials requiring metal ions for efficient drug binding. While the presence of metal ions in topos has been elucidated in biochemical studies, accurate location and assignment of metal ions in structural studies have historically posed significant challenges. Recent advances in X-ray crystallography address these limitations by extending the experimental capabilities into the long-wavelength range, exploiting the anomalous contrast from light elements of biological relevance. This breakthrough enables us to confirm experimentally the locations of Mg2+ in the fluoroquinolone-stabilized Streptococcus pneumoniae topo IV complex. Moreover, we can unambiguously identify the presence of K+ and Cl- ions in the complex with one pair of K+ ions functioning as an additional intersubunit bridge. Overall, our data extend current knowledge on the functional and structural roles of metal ions in type II topos.
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Affiliation(s)
- Beijia Wang
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Shabir Najmudin
- Molecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, St. George's, University of London, London SW17 0RE, United Kingdom
| | - Xiao-Su Pan
- Molecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, St. George's, University of London, London SW17 0RE, United Kingdom
| | - Vitaliy Mykhaylyk
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Christian Orr
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Armin Wagner
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Lata Govada
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Naomi E Chayen
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - L Mark Fisher
- Molecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, St. George's, University of London, London SW17 0RE, United Kingdom
| | - Mark R Sanderson
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom
- Molecular and Cellular Sciences Section, Neuroscience and Cell Biology Research Institute, St. George's, University of London, London SW17 0RE, United Kingdom
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2
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Liu KT, Chen SF, Chan NL. Structural insights into the assembly of type IIA topoisomerase DNA cleavage-religation center. Nucleic Acids Res 2024; 52:9788-9802. [PMID: 39077950 PMCID: PMC11381327 DOI: 10.1093/nar/gkae657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 07/09/2024] [Accepted: 07/16/2024] [Indexed: 07/31/2024] Open
Abstract
The ability to catalyze reversible DNA cleavage and religation is central to topoisomerases' role in regulating DNA topology. In type IIA topoisomerases (Top2), the formation of its DNA cleavage-religation center is driven by DNA-binding-induced structural rearrangements. These changes optimally position key catalytic modules, such as the active site tyrosine of the WHD domain and metal ion(s) chelated by the TOPRIM domain, around the scissile phosphodiester bond to perform reversible transesterification. To understand this assembly process in detail, we report the catalytic core structures of human Top2α and Top2β in an on-pathway conformational state. This state features an in trans formation of an interface between the Tower and opposing TOPRIM domain, revealing a groove for accommodating incoming G-segment DNA. Structural superimposition further unveils how subsequent DNA-binding-induced disengagement of the TOPRIM and Tower domains allows a firm grasp of the bound DNA for cleavage/religation. Notably, we identified a previously undocumented protein-DNA interaction, formed between an arginine-capped C-terminus of an α-helix in the TOPRIM domain and the DNA backbone, significantly contributing to Top2 function. This work uncovers a previously unrecognized role of the Tower domain, highlighting its involvement in anchoring and releasing the TOPRIM domain, thus priming Top2 for DNA binding and cleavage.
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Affiliation(s)
- Ko-Ting Liu
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Shin-Fu Chen
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Nei-Li Chan
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
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3
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Wang Z, Wang G, Zhao P, Sun P. The liquid-liquid phase separation signature predicts the prognosis and immunotherapy response in hepatocellular carcinoma. J Cell Mol Med 2024; 28:e18446. [PMID: 39072983 DOI: 10.1111/jcmm.18446] [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: 11/20/2023] [Revised: 03/28/2024] [Accepted: 05/13/2024] [Indexed: 07/30/2024] Open
Abstract
Hepatocellular carcinoma (HCC) is a common and fatal malignancy characterized by poor patient prognosis and treatment outcome. The process of liquid-liquid phase separation in tumour cells alters the dysfunction of biomolecular condensation in tumour cells, which affects tumour progression and treatment. We downloaded the data of HCC samples from TCGA database and GEO database, and used a machine learning method to build a new liquid-liquid phase separation index (LLPSI) by liquid-liquid phase separation related genes. The LLPSI-related column line Figure was constructed to provide a quantitative tool for clinical practice. HCC patients were divided into high and low LLPSI groups based on LLPSI, and clinical features, tumour immune microenvironment, chemotherapeutic response, and immunotherapeutic response were systematically analysed. LLPSI, which consists of five liquid-liquid phase separation-associated genes (MAPT, WDR62, PLK1, CDCA8 and TOP2A), is a reliable predictor of survival in patients with HCC and has been validated in multiple external datasets. We found that the high LLPSI group showed higher levels of immune cell infiltration and better response to immunotherapy compared to the low LLPSI group, and LLPSI can also be used for prognostic prediction in various cancers other than HCC. In vitro experiments verified that knockdown of MAPT could inhibit the proliferation and migration of HCC. The LLPSI identified in this study can accurately assess the prognosis of patients with HCC and identify patient populations that will benefit from immunotherapy, providing valuable insights into the clinical management of HCC.
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Affiliation(s)
- Zhiyong Wang
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guoliang Wang
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peng Zhao
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ping Sun
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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4
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Herlah B, Pavlin M, Perdih A. Molecular choreography: Unveiling the dynamic landscape of type IIA DNA topoisomerases before T-segment passage through all-atom simulations. Int J Biol Macromol 2024; 269:131991. [PMID: 38714283 DOI: 10.1016/j.ijbiomac.2024.131991] [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: 01/09/2024] [Revised: 04/09/2024] [Accepted: 04/28/2024] [Indexed: 05/09/2024]
Abstract
Type IIA DNA topoisomerases are molecular nanomachines responsible for controlling topological states of DNA molecules. Here, we explore the dynamic landscape of yeast topoisomerase IIA during key stages of its catalytic cycle, focusing in particular on the events preceding the passage of the T-segment. To this end, we generated six configurations of fully catalytic yeast topo IIA, strategically inserted a T-segment into the N-gate in relevant configurations, and performed all-atom simulations. The essential motion of topo IIA protein dimer was characterized by rotational gyrating-like movement together with sliding motion within the DNA-gate. Both appear to be inherent properties of the enzyme and an inbuilt feature that allows passage of the T-segment through the cleaved G-segment. Coupled dynamics of the N-gate and DNA-gate residues may be particularly important for controlled and smooth passage of the T-segment and consequently the prevention of DNA double-strand breaks. QTK loop residue Lys367, which interacts with ATP and ADP molecules, is involved in regulating the size and stability of the N-gate. The unveiled features of the simulated configurations provide insights into the catalytic cycle of type IIA topoisomerases and elucidate the molecular choreography governing their ability to modulate the topological states of DNA topology.
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Affiliation(s)
- Barbara Herlah
- Theory Department, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Matic Pavlin
- Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Andrej Perdih
- Theory Department, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia.
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Collins J, Osheroff N. Gyrase and Topoisomerase IV: Recycling Old Targets for New Antibacterials to Combat Fluoroquinolone Resistance. ACS Infect Dis 2024; 10:1097-1115. [PMID: 38564341 PMCID: PMC11019561 DOI: 10.1021/acsinfecdis.4c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 03/14/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Beyond their requisite functions in many critical DNA processes, the bacterial type II topoisomerases, gyrase and topoisomerase IV, are the targets of fluoroquinolone antibacterials. These drugs act by stabilizing gyrase/topoisomerase IV-generated DNA strand breaks and by robbing the cell of the catalytic activities of these essential enzymes. Since their clinical approval in the mid-1980s, fluoroquinolones have been used to treat a broad spectrum of infectious diseases and are listed among the five "highest priority" critically important antimicrobial classes by the World Health Organization. Unfortunately, the widespread use of fluoroquinolones has been accompanied by a rise in target-mediated resistance caused by specific mutations in gyrase and topoisomerase IV, which has curtailed the medical efficacy of this drug class. As a result, efforts are underway to identify novel antibacterials that target the bacterial type II topoisomerases. Several new classes of gyrase/topoisomerase IV-targeted antibacterials have emerged, including novel bacterial topoisomerase inhibitors, Mycobacterium tuberculosis gyrase inhibitors, triazaacenaphthylenes, spiropyrimidinetriones, and thiophenes. Phase III clinical trials that utilized two members of these classes, gepotidacin (triazaacenaphthylene) and zoliflodacin (spiropyrimidinetrione), have been completed with positive outcomes, underscoring the potential of these compounds to become the first new classes of antibacterials introduced into the clinic in decades. Because gyrase and topoisomerase IV are validated targets for established and emerging antibacterials, this review will describe the catalytic mechanism and cellular activities of the bacterial type II topoisomerases, their interactions with fluoroquinolones, the mechanism of target-mediated fluoroquinolone resistance, and the actions of novel antibacterials against wild-type and fluoroquinolone-resistant gyrase and topoisomerase IV.
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Affiliation(s)
- Jessica
A. Collins
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
| | - Neil Osheroff
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
- Department
of Medicine (Hematology/Oncology), Vanderbilt
University School of Medicine, Nashville, Tennessee 37232, United States
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6
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Zhang B, Li J, Wang Y, Liu X, Yang X, Liao Z, Deng S, Deng Y, Zhou Z, Tian Y, Wei W, Meng J, Hu Y, Wan C, Zhang Z, Huang F, Wen L, Wu B, Sun Y, Li Y, Yang K. Deubiquitinase USP7 stabilizes KDM5B and promotes tumor progression and cisplatin resistance in nasopharyngeal carcinoma through the ZBTB16/TOP2A axis. Cell Death Differ 2024; 31:309-321. [PMID: 38287116 PMCID: PMC10923876 DOI: 10.1038/s41418-024-01257-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/31/2024] Open
Abstract
Cisplatin-based chemotherapy improves the control of distant metastases in patients with nasopharyngeal carcinoma (NPC); however, around 30% of patients fail treatment due to acquired drug resistance. Epigenetic regulation is known to contribute to cisplatin resistance; nevertheless, the underlying mechanisms remain poorly understood. Here, we showed that lysine-specific demethylase 5B (KDM5B) was overexpressed and correlates with tumor progression and cisplatin resistance in patients with NPC. We also showed that specific inhibition of KDM5B impaired the progression of NPC and reverses cisplatin resistance, both in vitro and in vivo. Moreover, we found that KDM5B inhibited the expression of ZBTB16 by directly reducing H3K4me3 at the ZBTB16 promoter, which subsequently increased the expression of Topoisomerase II- α (TOP2A) to confer cisplatin resistance in NPC. In addition, we showed that the deubiquitinase USP7 was critical for deubiquitinating and stabilizing KDM5B. More importantly, the deletion of USP7 increased sensitivity to cisplatin by disrupting the stability of KDM5B in NPC cells. Therefore, our findings demonstrated that USP7 stabilized KDM5B and promoted cisplatin resistance through the ZBTB16/TOP2A axis, suggesting that targeting KDM5B may be a promising cisplatin-sensitization strategy in the treatment of NPC.
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Affiliation(s)
- Bin Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Jie Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Yijun Wang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Xixi Liu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Xiao Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Zhiyun Liao
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Suke Deng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Yue Deng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Zhiyuan Zhou
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Yu Tian
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Wenwen Wei
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Jingshu Meng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Yan Hu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Chao Wan
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Zhanjie Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Fang Huang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Lu Wen
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Bian Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Yajie Sun
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China.
| | - Yan Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China.
| | - Kunyu Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China.
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Pavlin M, Herlah B, Valjavec K, Perdih A. Unveiling the interdomain dynamics of type II DNA topoisomerase through all-atom simulations: Implications for understanding its catalytic cycle. Comput Struct Biotechnol J 2023; 21:3746-3759. [PMID: 37602233 PMCID: PMC10436251 DOI: 10.1016/j.csbj.2023.07.019] [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: 04/23/2023] [Revised: 07/01/2023] [Accepted: 07/19/2023] [Indexed: 08/22/2023] Open
Abstract
Type IIA DNA topoisomerases are complex molecular nanomachines that manage topological states of the DNA molecule in the cell and play a crucial role in cellular processes such as cell division and transcription. They are also established targets of cancer chemotherapy. Starting from the available crystal structure of a fully catalytic topoisomerase IIA homodimer from Saccharomyces cerevisiae, we constructed three states of this molecular motor primarily changing the configurations of the DNA segment bound in the DNA gate and performed μs-long all-atom molecular simulations. A comprehensive analysis revealed a sliding motion within the DNA gate and a teamwork between the N-gate and DNA gate that may be associated with the necessary molecular events that allow passage of the T-segment of DNA. The observed movement of the ATPase dimer relative to the DNA domain was reflected in different interaction patterns between the K-loops of the transducer domain and the B-A-B form of the bound DNA. Based on the obtained results, we mapped simulated configurations to the structures in the proposed catalytic cycle through which type IIA topoisomerases exert their function and discussed the possible transition events. The results extend our understanding of the mechanism of action of type IIA topoisomerases and provide an atomistic interpretation of some of the observed features of these molecular motors.
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Affiliation(s)
- Matic Pavlin
- Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Barbara Herlah
- Theory Department, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Katja Valjavec
- Theory Department, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Andrej Perdih
- Theory Department, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia
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8
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Jian JY, Osheroff N. Telling Your Right Hand from Your Left: The Effects of DNA Supercoil Handedness on the Actions of Type II Topoisomerases. Int J Mol Sci 2023; 24:11199. [PMID: 37446377 PMCID: PMC10342825 DOI: 10.3390/ijms241311199] [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: 06/16/2023] [Revised: 07/05/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Type II topoisomerases are essential enzymes that modulate the topological state of DNA supercoiling in all living organisms. These enzymes alter DNA topology by performing double-stranded passage reactions on over- or underwound DNA substrates. This strand passage reaction generates a transient covalent enzyme-cleaved DNA structure known as the cleavage complex. Al-though the cleavage complex is a requisite catalytic intermediate, it is also intrinsically dangerous to genomic stability in biological systems. The potential threat of type II topoisomerase function can also vary based on the nature of the supercoiled DNA substrate. During essential processes such as DNA replication and transcription, cleavage complex formation can be inherently more dangerous on overwound versus underwound DNA substrates. As such, it is important to understand the profound effects that DNA topology can have on the cellular functions of type II topoisomerases. This review will provide a broad assessment of how human and bacterial type II topoisomerases recognize and act on their substrates of various topological states.
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Affiliation(s)
- Jeffrey Y. Jian
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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9
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Bartas M, Slychko K, Červeň J, Pečinka P, Arndt-Jovin DJ, Jovin TM. Extensive Bioinformatics Analyses Reveal a Phylogenetically Conserved Winged Helix (WH) Domain (Zτ) of Topoisomerase IIα, Elucidating Its Very High Affinity for Left-Handed Z-DNA and Suggesting Novel Putative Functions. Int J Mol Sci 2023; 24:10740. [PMID: 37445918 DOI: 10.3390/ijms241310740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/13/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
The dynamic processes operating on genomic DNA, such as gene expression and cellular division, lead inexorably to topological challenges in the form of entanglements, catenanes, knots, "bubbles", R-loops, and other outcomes of supercoiling and helical disruption. The resolution of toxic topological stress is the function attributed to DNA topoisomerases. A prominent example is the negative supercoiling (nsc) trailing processive enzymes such as DNA and RNA polymerases. The multiple equilibrium states that nscDNA can adopt by redistribution of helical twist and writhe include the left-handed double-helical conformation known as Z-DNA. Thirty years ago, one of our labs isolated a protein from Drosophila cells and embryos with a 100-fold greater affinity for Z-DNA than for B-DNA, and identified it as topoisomerase II (gene Top2, orthologous to the human UniProt proteins TOP2A and TOP2B). GTP increased the affinity and selectivity for Z-DNA even further and also led to inhibition of the isomerase enzymatic activity. An allosteric mechanism was proposed, in which topoII acts as a Z-DNA-binding protein (ZBP) to stabilize given states of topological (sub)domains and associated multiprotein complexes. We have now explored this possibility by comprehensive bioinformatic analyses of the available protein sequences of topoII representing organisms covering the whole tree of life. Multiple alignment of these sequences revealed an extremely high level of evolutionary conservation, including a winged-helix protein segment, here denoted as Zτ, constituting the putative structural homolog of Zα, the canonical Z-DNA/Z-RNA binding domain previously identified in the interferon-inducible RNA Adenosine-to-Inosine-editing deaminase, ADAR1p150. In contrast to Zα, which is separate from the protein segment responsible for catalysis, Zτ encompasses the active site tyrosine of topoII; a GTP-binding site and a GxxG sequence motif are in close proximity. Quantitative Zτ-Zα similarity comparisons and molecular docking with interaction scoring further supported the "B-Z-topoII hypothesis" and has led to an expanded mechanism for topoII function incorporating the recognition of Z-DNA segments ("Z-flipons") as an inherent and essential element. We further propose that the two Zτ domains of the topoII homodimer exhibit a single-turnover "conformase" activity on given G(ate) B-DNA segments ("Z-flipins"), inducing their transition to the left-handed Z-conformation. Inasmuch as the topoII-Z-DNA complexes are isomerase inactive, we infer that they fulfill important structural roles in key processes such as mitosis. Topoisomerases are preeminent targets of anti-cancer drug discovery, and we anticipate that detailed elucidation of their structural-functional interactions with Z-DNA and GTP will facilitate the design of novel, more potent and selective anti-cancer chemotherapeutic agents.
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Affiliation(s)
- Martin Bartas
- Department of Biology and Ecology, University of Ostrava, 710 00 Ostrava, Czech Republic
| | - Kristyna Slychko
- Department of Biology and Ecology, University of Ostrava, 710 00 Ostrava, Czech Republic
| | - Jiří Červeň
- Department of Biology and Ecology, University of Ostrava, 710 00 Ostrava, Czech Republic
| | - Petr Pečinka
- Department of Biology and Ecology, University of Ostrava, 710 00 Ostrava, Czech Republic
| | - Donna J Arndt-Jovin
- Emeritus Laboratory of Cellular Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
| | - Thomas M Jovin
- Emeritus Laboratory of Cellular Dynamics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
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10
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Chin HK, Lu MC, Hsu KC, El-Shazly M, Tsai TN, Lin TY, Shih SP, Lin TE, Wen ZH, Yang YCSH, Liu YC. Exploration of anti-leukemic effect of soft coral-derived 13-acetoxysarcocrassolide: Induction of apoptosis via oxidative stress as a potent inhibitor of heat shock protein 90 and topoisomerase II. Kaohsiung J Med Sci 2023. [PMID: 37052190 DOI: 10.1002/kjm2.12678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 02/21/2023] [Accepted: 03/01/2023] [Indexed: 04/14/2023] Open
Abstract
13-Acetoxysarcocrassolide (13-AC) is a marine cembranoid derived from the aquaculture soft coral of Lobophytum crassum. The cytotoxic effect of 13-AC against leukemia cells was previously reported but its mechanism of action is still unexplored. In the current study, we showed that 13-AC induced apoptosis of human acute lymphoblastic leukemia Molt4 cells, as evidenced by the cleavage of PARP and caspases, phosphatidylserine externalization, as well as the disruption of mitochondrial membrane potential. The use of N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, attenuated the cytotoxic effect induced by 13-AC. Molecular docking and thermal shift assay indicated that the cytotoxic mechanism of action of 13-AC involved the inhibition of heat shock protein 90 (Hsp 90) activity by eliciting the level of Hsp 70 and topoisomerase IIα in Molt4 cells. 13-AC also exhibited potent antitumor activity by reducing the tumor volume (48.3%) and weight (72.5%) in the in vivo Molt4 xenograft mice model. Our findings suggested that the marine cembranoid, 13-AC, acted as a dual inhibitor of Hsp 90 and topoisomerase IIα, exerting more potent apoptotic activity via the enhancement of ROS generation.
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Affiliation(s)
- Hsien-Kuo Chin
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan
- Division of Cardiovascular Surgery, Department of Surgery, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan
| | - Mei-Chin Lu
- Graduate Institute of Marine Biology, National Dong Hwa University, Hualien, Taiwan
- National Museum of Marine Biology and Aquarium, Pingtung, Taiwan
| | - Kai-Cheng Hsu
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Master Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- TMU Research Center of Drug Discovery, Taipei Medical University, Taipei, Taiwan
| | - Mohamed El-Shazly
- Department of Pharmacognosy, Faculty of Pharmacy, Ain-Shams University, Cairo, Egypt
| | - Tsen-Ni Tsai
- Graduate Institute of Marine Biology, National Dong Hwa University, Hualien, Taiwan
- Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Tzu-Yung Lin
- Department and Graduate Institute of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
| | - Shou-Ping Shih
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, Academia Sinica, Taipei, Taiwan
| | - Tony Eight Lin
- Master Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Yu-Chen S H Yang
- Joint Biobank, Office of Human Research, Taipei Medical University, Taipei, Taiwan
| | - Yi-Chang Liu
- Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Internal Medicine, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Cellular Therapy and Research Center, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
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11
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Smiley AT, Tompkins KJ, Pawlak MR, Krueger AJ, Evans RL, Shi K, Aihara H, Gordon WR. Watson-Crick Base-Pairing Requirements for ssDNA Recognition and Processing in Replication-Initiating HUH Endonucleases. mBio 2023; 14:e0258722. [PMID: 36541758 PMCID: PMC9973303 DOI: 10.1128/mbio.02587-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Replication-initiating HUH endonucleases (Reps) are sequence-specific nucleases that cleave and rejoin single-stranded DNA (ssDNA) during rolling-circle replication. These functions are mediated by covalent linkage of the Rep to its substrate post cleavage. Here, we describe the structures of the endonuclease domain from the Muscovy duck circovirus Rep in complex with its cognate ssDNA 10-mer with and without manganese in the active site. Structural and functional analyses demonstrate that divalent cations play both catalytic and structural roles in Reps by polarizing and positioning their substrate. Further structural comparisons highlight the importance of an intramolecular substrate Watson-Crick (WC) base pairing between the -4 and +1 positions. Subsequent kinetic and functional analyses demonstrate a functional dependency on WC base pairing between these positions regardless of the pair's identity (i.e., A·T, T·A, G·C, or C·G), highlighting a structural specificity for substrate interaction. Finally, considering how well WC swaps were tolerated in vitro, we sought to determine to what extent the canonical -4T·+1A pairing is conserved in circular Rep-encoding single-stranded DNA viruses and found evidence of noncanonical pairings in a minority of these genomes. Altogether, our data suggest that substrate intramolecular WC base pairing is a universal requirement for separation and reunion of ssDNA in Reps. IMPORTANCE Circular Rep-encoding single-stranded DNA (CRESS-DNA) viruses are a ubiquitous group of viruses that infect organisms across all domains of life. These viruses negatively impact both agriculture and human health. All members of this viral family employ a multifunctional nuclease (Rep) to initiate replication. Reps are structurally similar throughout this family, making them targets of interest for viral inhibition strategies. Here, we investigate the functional dependencies of the Rep protein from Muscovy duck circovirus for ssDNA interaction. We demonstrate that this Rep requires an intramolecular Watson-Crick base pairing for origin of replication (Ori) recognition and interaction. We show that noncognate base pair swaps are well tolerated, highlighting a local structural specificity over sequence specificity. Bioinformatic analysis found that the vast majority of CRESS-DNA Oris form base pairs in conserved positions, suggesting this pairing is a universal requirement for replication initiation in the CRESS-DNA virus family.
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Affiliation(s)
- Adam T. Smiley
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kassidy J. Tompkins
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Matthew R. Pawlak
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - August J. Krueger
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robert L. Evans
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Wendy R. Gordon
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
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12
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Olatunde OZ, Yong J, Lu C, Ming Y. A Review on Shikonin and Its Derivatives as Potent Anticancer Agents Targeted against Topoisomerases. Curr Med Chem 2023; 31:CMC-EPUB-129356. [PMID: 36752292 DOI: 10.2174/0929867330666230208094828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/12/2022] [Accepted: 11/30/2022] [Indexed: 02/09/2023]
Abstract
The topoisomerases (TOPO) play indispensable roles in DNA metabolism, by regulating the topological state of DNA. Topoisomerase I and II are the well-established drug-targets for the development of anticancer agents and antibiotics. These drugs-targeting enzymes have been used to establish the relationship between drug-stimulated DNA cleavable complex formation and cytotoxicity. Some anticancer drugs (such as camptothecin, anthracyclines, mitoxantrone) are also widely used as Topo I and Topo II inhibitors, but the poor water solubility, myeloma suppression, dose-dependent cardiotoxicity, and multidrug resistance (MDR) limited their prolong use as therapeutics. Also, most of these agents displayed selective inhibition only against Topo I or II. In recent years, researchers focus on the design and synthesis of the dual Topo I and II inhibitors, or the discovery of the dual Topo I and II inhibitors from natural products. Shikonin (a natural compound with anthraquinone skeleton, isolated from the roots of Lithospermum erythrorhizon) has drawn much attention due to its wide spectrum of anticancer activities, especially due to its dual Topo inhibitive performance, and without the adverse side effects, and different kinds of shikonin derivatives have been synthesized as TOPO inhibitors for the development of anticancer agents. In this review, the progress of the shikonin and its derivatives together with their anticancer activities, anticancer mechanism, and their structure-activity relationship (SAR) was comprehensively summarized by searching the CNKI, PubMed, Web of Science, Scopus, and Google Scholar databases.
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Affiliation(s)
- Olagoke Zacchaeus Olatunde
- Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian,350002, China
| | - Jianping Yong
- Xiamen Institute of Rare-earth Materials, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
| | - Canzhong Lu
- Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian,350002, China
- Xiamen Institute of Rare-earth Materials, Chinese Academy of Sciences, Xiamen, Fujian, 361021, China
| | - Yanlin Ming
- Fujian Institute of Subtropical Botany, Xiamen, Fujian, 361006, China
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13
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Ogrizek M, Janežič M, Valjavec K, Perdih A. Catalytic Mechanism of ATP Hydrolysis in the ATPase Domain of Human DNA Topoisomerase IIα. J Chem Inf Model 2022; 62:3896-3909. [PMID: 35948041 PMCID: PMC9400105 DOI: 10.1021/acs.jcim.2c00303] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Human DNA topoisomerase IIα is a biological nanomachine
that
regulates the topological changes of the DNA molecule and is considered
a prime target for anticancer drugs. Despite intensive research, many
atomic details about its mechanism of action remain unknown. We investigated
the ATPase domain, a segment of the human DNA topoisomerase IIα,
using all-atom molecular simulations, multiscale quantum mechanics/molecular
mechanics (QM/MM) calculations, and a point mutation study. The results
suggested that the binding of ATP affects the overall dynamics of
the ATPase dimer. Reaction modeling revealed that ATP hydrolysis favors
the dissociative substrate-assisted reaction mechanism with the catalytic
Glu87 serving to properly position and polarize the lytic water molecule.
The point mutation study complemented our computational results, demonstrating
that Lys378, part of the important QTK loop, acts as a stabilizing
residue. The work aims to pave the way to a deeper understanding of
these important molecular motors and to advance the development of
new therapeutics.
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Affiliation(s)
- Mitja Ogrizek
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Matej Janežič
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Katja Valjavec
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Andrej Perdih
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.,Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI 1000 Ljubljana, Slovenia
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14
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Dong C, Liu W, Zhang Y, Song Y, Du J, Huang Z, Wang T, Yu Z, Ma X. Identification of Common Hub Genes in Human Dermal Fibroblasts Stimulated by Mechanical Stretch at Both the Early and Late Stages. Front Surg 2022; 9:846161. [PMID: 35510126 PMCID: PMC9058084 DOI: 10.3389/fsurg.2022.846161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/16/2022] [Indexed: 11/25/2022] Open
Abstract
Background Mechanical stretch is vital for soft tissue regeneration and development and is utilized by plastic surgeons for tissue expansion. Identifying the common hub genes in human dermal fibroblasts (HDFs) stimulated by mechanical stretch at different stages will help elucidate the mechanisms involved and improve the efficiency of tissue expansion. Methods A gene expression dataset (GSE58389) was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) in HDFs between cyclic mechanical stretching and static samples were identified at 5 and 24 h. Common DEGs overlapped in both the 5 h and 24 h groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to determine the functions of the DEGs. Protein-protein interaction networks were constructed using the STRING database. The top 10 hub genes were selected using the plug-in Cytohubba within Cytoscape. The regulatory network of hub genes was predicted using NetworkAnalyst. Results A total of 669 and 249 DEGs were identified at the early (5 h) and late stages (24 h), respectively. Of these, 152 were present at both stages and were designated as common DEGs. The top enriched GO terms were “regulation of autophagy” at the early stage, and “sterol biosynthetic processes” at the late stage. The top KEGG terms were “pyrimidine metabolism” and “synaptic vesicle cycle” at the early and late stages, respectively. Seven common DEGs [DEAD-box helicase 17 (DDX17), exocyst complex component 7 (EXOC7), CASK interacting protein 1 (CASKIN1), ribonucleoprotein PTB-binding 1 (RAVER1), late cornified envelope 1D (LCE1D), LCE1C, and polycystin 1, transient receptor potential channel interacting (PKD1)] and three common DEGs [5′-3′ exoribonuclease 2 (XRN2), T-complex protein 1 (TCP1), and syntaxin 3 (STX3)] were shown to be upregulated and downregulated hub genes, respectively. The GO terms of the common hub genes were “skin development” and “mRNA processing.” After constructing the regulatory network, hsa-mir-92a-3p, hsa-mir-193b-3p, RNA polymerase II subunit A (POLR2A), SMAD family member 5 (SMAD5), and MYC-associated zinc finger protein (MAZ) were predicted as potential targets in both stages. Conclusion At the early stage, there were clear changes in gene expression related to DNA and chromatin alterations; at late stages, gene expression associated with cholesterol metabolism was suppressed. Common DEGs related to skin development, transcriptional regulation, and cytoskeleton rearrangement identified in both stages were found to be potential targets for promoting HDF growth and alignment under mechanical stretch.
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15
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Boot A, Liu M, Stantial N, Shah V, Yu W, Nitiss KC, Nitiss JL, Jinks-Robertson S, Rozen SG. Recurrent mutations in topoisomerase IIα cause a previously undescribed mutator phenotype in human cancers. Proc Natl Acad Sci U S A 2022; 119:e2114024119. [PMID: 35058360 PMCID: PMC8795545 DOI: 10.1073/pnas.2114024119] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/13/2021] [Indexed: 01/01/2023] Open
Abstract
Topoisomerases nick and reseal DNA to relieve torsional stress associated with transcription and replication and to resolve structures such as knots and catenanes. Stabilization of the yeast Top2 cleavage intermediates is mutagenic in yeast, but whether this extends to higher eukaryotes is less clear. Chemotherapeutic topoisomerase poisons also elevate cleavage, resulting in mutagenesis. Here, we describe p.K743N mutations in human topoisomerase hTOP2α and link them to a previously undescribed mutator phenotype in cancer. Overexpression of the orthologous mutant protein in yeast generated a characteristic pattern of 2- to 4-base pair (bp) duplications resembling those in tumors with p.K743N. Using mutant strains and biochemical analysis, we determined the genetic requirements of this mutagenic process and showed that it results from trapping of the mutant yeast yTop2 cleavage complex. In addition to 2- to 4-bp duplications, hTOP2α p.K743N is also associated with deletions that are absent in yeast. We call the combined pattern of duplications and deletions ID_TOP2α. All seven tumors carrying the hTOP2α p.K743N mutation showed ID_TOP2α, while it was absent from all other tumors examined (n = 12,269). Each tumor with the ID_TOP2α signature had indels in several known cancer genes, which included frameshift mutations in tumor suppressors PTEN and TP53 and an activating insertion in BRAF. Sequence motifs found at ID_TOP2α mutations were present at 80% of indels in cancer-driver genes, suggesting that ID_TOP2α mutagenesis may contribute to tumorigenesis. The results reported here shed further light on the role of topoisomerase II in genome instability.
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Affiliation(s)
- Arnoud Boot
- Programme in Cancer and Stem Cell Biology, Duke University-National University of Singapore Medical School (Duke-NUS Medical School), 169857 Singapore;
- Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - Mo Liu
- Programme in Cancer and Stem Cell Biology, Duke University-National University of Singapore Medical School (Duke-NUS Medical School), 169857 Singapore
- Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - Nicole Stantial
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710
| | - Viraj Shah
- Pharmaceutical Sciences Department, University of Illinois at Chicago, Rockford, IL 61107
| | - Willie Yu
- Programme in Cancer and Stem Cell Biology, Duke University-National University of Singapore Medical School (Duke-NUS Medical School), 169857 Singapore
- Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - Karin C Nitiss
- Pharmaceutical Sciences Department, University of Illinois at Chicago, Rockford, IL 61107
| | - John L Nitiss
- Pharmaceutical Sciences Department, University of Illinois at Chicago, Rockford, IL 61107
| | - Sue Jinks-Robertson
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710;
| | - Steven G Rozen
- Programme in Cancer and Stem Cell Biology, Duke University-National University of Singapore Medical School (Duke-NUS Medical School), 169857 Singapore;
- Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
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16
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Vann KR, Oviatt AA, Osheroff N. Topoisomerase II Poisons: Converting Essential Enzymes into Molecular Scissors. Biochemistry 2021; 60:1630-1641. [PMID: 34008964 PMCID: PMC8209676 DOI: 10.1021/acs.biochem.1c00240] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The extensive length, compaction, and interwound nature of DNA, together with its controlled and restricted movement in eukaryotic cells, create a number of topological issues that profoundly affect all of the functions of the genetic material. Topoisomerases are essential enzymes that modulate the topological structure of the double helix, including the regulation of DNA under- and overwinding and the removal of tangles and knots from the genome. Type II topoisomerases alter DNA topology by generating a transient double-stranded break in one DNA segment and allowing another segment to pass through the DNA gate. These enzymes are involved in a number of critical nuclear processes in eukaryotic cells, such as DNA replication, transcription, and recombination, and are required for proper chromosome structure and segregation. However, because type II topoisomerases generate double-stranded breaks in the genetic material, they also are intrinsically dangerous enzymes that have the capacity to fragment the genome. As a result of this dualistic nature, type II topoisomerases are the targets for a number of widely prescribed anticancer drugs. This article will describe the structure and catalytic mechanism of eukaryotic type II topoisomerases and will go on to discuss the actions of topoisomerase II poisons, which are compounds that stabilize DNA breaks generated by the type II enzyme and convert these essential enzymes into "molecular scissors." Topoisomerase II poisons represent a broad range of structural classes and include anticancer drugs, dietary components, and environmental chemicals.
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Affiliation(s)
- Kendra R Vann
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Alexandria A Oviatt
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Neil Osheroff
- Departments of Biochemistry and Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- VA Tennessee Valley Healthcare System, Nashville, Tennessee 37212, United States
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McKie SJ, Neuman KC, Maxwell A. DNA topoisomerases: Advances in understanding of cellular roles and multi-protein complexes via structure-function analysis. Bioessays 2021; 43:e2000286. [PMID: 33480441 PMCID: PMC7614492 DOI: 10.1002/bies.202000286] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/06/2020] [Accepted: 12/17/2020] [Indexed: 12/15/2022]
Abstract
DNA topoisomerases, capable of manipulating DNA topology, are ubiquitous and indispensable for cellular survival due to the numerous roles they play during DNA metabolism. As we review here, current structural approaches have revealed unprecedented insights into the complex DNA-topoisomerase interaction and strand passage mechanism, helping to advance our understanding of their activities in vivo. This has been complemented by single-molecule techniques, which have facilitated the detailed dissection of the various topoisomerase reactions. Recent work has also revealed the importance of topoisomerase interactions with accessory proteins and other DNA-associated proteins, supporting the idea that they often function as part of multi-enzyme assemblies in vivo. In addition, novel topoisomerases have been identified and explored, such as topo VIII and Mini-A. These new findings are advancing our understanding of DNA-related processes and the vital functions topos fulfil, demonstrating their indispensability in virtually every aspect of DNA metabolism.
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Affiliation(s)
- Shannon J. McKie
- Department Biological Chemistry, John Innes Centre, Norwich, UK
- Laboratory of Single Molecule Biophysics, NHLBI, Bethesda, Maryland, USA
| | - Keir C. Neuman
- Laboratory of Single Molecule Biophysics, NHLBI, Bethesda, Maryland, USA
| | - Anthony Maxwell
- Department Biological Chemistry, John Innes Centre, Norwich, UK
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Wei LM, Li XY, Wang ZM, Wang YK, Yao G, Fan JH, Wang XS. Identification of hub genes in triple-negative breast cancer by integrated bioinformatics analysis. Gland Surg 2021; 10:799-806. [PMID: 33708561 DOI: 10.21037/gs-21-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Triple negative breast cancer (TNBC) is usually aggressive and accompanied by a poor prognosis. The molecular biological mechanism of TNBC pathogenesis is still unclear, and requires more detailed research. The aim of this study was to screen and verify potential biomarkers of TNBC, and provide new clues for the treatment and diagnosis of TNBC. Methods In this work, GSE76250 was downloaded from the Gene Expression Omnibus (GEO) database and included 165 TNBC samples and 33 paired normal breast tissues. The R software and its related software package were used for data processing and analysis. Compared with normal tissues, genes with a false discovery rate (FDR) <0.01 and log fold change (logFC) ≥1 or ≤-1 were identified as differentially expressed genes (DEGs) by limma package. Survival prognoses were analyzed by Kaplan-Meier plotter database. Results In total, 160 up-regulated and 180 down-regulated genes were identified. The biological mechanism of enrichment analysis presented that DEGs were significantly enriched in chromosome segregation, extracellular matrix, and extracellular matrix structural constituent, among others. A total of 8 hub genes (CCNB1, CDK1, TOP2A, MKI67, TTK, CCNA2, BUB1, and PLK1) were identified by the protein-protein interaction network (PPIN) and Cytoscape software. Survival prognosis of these hub genes showed that they were negatively correlated with overall survival. Conclusions The 8 hub genes and pathways that were identified might be involved in tumorigenesis and become new candidate biomarkers for TNBC treatment.
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Affiliation(s)
- Li-Min Wei
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
| | - Xin-Yang Li
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
| | - Zi-Ming Wang
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
| | - Yu-Kun Wang
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
| | - Ge Yao
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
| | - Jia-Hao Fan
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
| | - Xin-Shuai Wang
- Department of Cancer Institute, The First Affiliated Hospital and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, China
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19
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Kawano S, Fujimoto K, Yasuda K, Ikeda S. DNA binding activity of the proximal C-terminal domain of rat DNA topoisomerase IIβ is involved in ICRF-193-induced closed-clamp formation. PLoS One 2020; 15:e0239466. [PMID: 32960919 PMCID: PMC7508362 DOI: 10.1371/journal.pone.0239466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/08/2020] [Indexed: 11/30/2022] Open
Abstract
DNA topoisomerase II (topo II) is an essential enzyme that regulates DNA topology by DNA cleavage and re-ligation. In vertebrates, there are two isozymes, α and β. The C-terminal domain (CTD) of the isozymes, which shows a low degree of sequence homology between α and β, is involved in each isozyme-specific intracellular behavior. The CTD of topo IIβ is supposedly involved in topo II regulation. Topo IIβ is maintained in an inactive state in the nucleoli by the binding of RNA to the 50-residue region termed C-terminal regulatory domain (CRD) present in the CTD. Although in vitro biochemical analysis indicates that the CTD of topo IIβ has DNA binding activity, it is unclear whether CTD influences catalytic reaction in the nucleoplasm. Here, we show that the proximal CTD (hereafter referred to as pCTD) of rat topo IIβ, including the CRD, is involved in the catalytic reaction in the nucleoplasm. We identified the pCTD as a domain with DNA binding activity by in vitro catenation assay and electrophoretic mobility shift assay. Fluorescence recovery after photo-bleaching (FRAP) analysis of pCTD-lacking mutant (ΔpCTD) showed higher mobility in nucleoplasm than that of the wild-type enzyme, indicating that the pCTD also affected the nuclear dynamics of topo IIβ. ICRF-193, one of the topo II catalytic inhibitors, induces the formation of closed-clamp intermediates of topo II. Treatment of ΔpCTD with ICRF-193 significantly decreased the efficiency of closed-clamp formation. Altogether, our data indicate that the binding of topo IIβ to DNA through the pCTD is required for the catalytic reaction in the nucleoplasm.
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Affiliation(s)
- Shinji Kawano
- Department of Biochemistry, Faculty of Science, Okayama University of Science, Okayama, Japan
- * E-mail:
| | - Kunpei Fujimoto
- Department of Biochemistry, Faculty of Science, Okayama University of Science, Okayama, Japan
| | - Kazushi Yasuda
- Department of Biochemistry, Faculty of Science, Okayama University of Science, Okayama, Japan
| | - Shogo Ikeda
- Department of Biochemistry, Faculty of Science, Okayama University of Science, Okayama, Japan
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20
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Majumdar D, Bhattacharjee SM. Softening of DNA near melting as disappearance of an emergent property. Phys Rev E 2020; 102:032407. [PMID: 33075941 DOI: 10.1103/physreve.102.032407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Near the melting transition the bending elastic constant κ, an emergent property of double-stranded DNA (dsDNA), is shown not to follow the rodlike scaling for small-length N. The reduction in κ with temperature is determined by the denatured bubbles for a continuous transition, e.g., when the two strands are Gaussian, but by the broken bonds near the open end in a Y-like configuration for a first-order transition as for strands with excluded volume interactions. In the latter case, a lever rule is operational, implying a phase coexistence although dsDNA is known to be a single phase.
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Affiliation(s)
- Debjyoti Majumdar
- Institute of Physics, Bhubaneswar, Odisha 751005, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
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21
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Radaeva M, Dong X, Cherkasov A. The Use of Methods of Computer-Aided Drug Discovery in the Development of Topoisomerase II Inhibitors: Applications and Future Directions. J Chem Inf Model 2020; 60:3703-3721. [DOI: 10.1021/acs.jcim.0c00325] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Mariia Radaeva
- Vancouver Prostate Centre, University of British Columbia, 2660 Oak Street, Vancouver, British Columbia V6H 3Z6, Canada
| | - Xuesen Dong
- Vancouver Prostate Centre, University of British Columbia, 2660 Oak Street, Vancouver, British Columbia V6H 3Z6, Canada
| | - Artem Cherkasov
- Vancouver Prostate Centre, University of British Columbia, 2660 Oak Street, Vancouver, British Columbia V6H 3Z6, Canada
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22
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He J, Tian Z, Yao X, Yao B, Liu Y, Yang J. A novel RNA sequencing-based risk score model to predict papillary thyroid carcinoma recurrence. Clin Exp Metastasis 2019; 37:257-267. [DOI: 10.1007/s10585-019-10011-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 11/25/2019] [Indexed: 12/24/2022]
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23
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Jang Y, Son H, Lee SW, Hwang W, Jung SR, Byl JAW, Osheroff N, Lee S. Selection of DNA Cleavage Sites by Topoisomerase II Results from Enzyme-Induced Flexibility of DNA. Cell Chem Biol 2019; 26:502-511.e3. [PMID: 30713098 DOI: 10.1016/j.chembiol.2018.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 10/04/2018] [Accepted: 12/04/2018] [Indexed: 12/26/2022]
Abstract
Topoisomerase II cleaves DNA at preferred sequences with different efficiencies; however, the mechanism of cleavage site selection is not known. Here we used single-molecule fluorescence assays that monitor several critical steps of DNA-topoisomerase II interactions, including binding/dissociation, bending/straightening, and cleavage/religation, and reveal that the cleavage site is selected mainly during the bending step. Furthermore, despite the sensitivity of the bending rate to the DNA sequence, it is not an intrinsic property of the DNA itself. Rather, it is determined by protein-DNA interactions.
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Affiliation(s)
- Yunsu Jang
- Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
| | - Heyjin Son
- Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
| | - Sang-Wook Lee
- Department of Physics and Astronomy, National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, South Korea
| | - Wonseok Hwang
- Department of Physics and Astronomy, National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, South Korea
| | - Seung-Ryoung Jung
- Department of Physics and Astronomy, National Center for Creative Research Initiatives, Seoul National University, Seoul 08826, South Korea
| | - Jo Ann W Byl
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; VA Tennessee Valley Healthcare System, Nashville, TN 37212, USA.
| | - Sanghwa Lee
- Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea.
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24
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Gibson EG, Blower TR, Cacho M, Bax B, Berger JM, Osheroff N. Mechanism of Action of Mycobacterium tuberculosis Gyrase Inhibitors: A Novel Class of Gyrase Poisons. ACS Infect Dis 2018; 4:1211-1222. [PMID: 29746087 DOI: 10.1021/acsinfecdis.8b00035] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tuberculosis is one of the leading causes of morbidity worldwide, and the incidences of drug resistance and intolerance are prevalent. Thus, there is a desperate need for the development of new antitubercular drugs. Mycobacterium tuberculosis gyrase inhibitors (MGIs) are napthyridone/aminopiperidine-based drugs that display activity against M. tuberculosis cells and tuberculosis in mouse models [Blanco, D., et al. (2015) Antimicrob. Agents Chemother. 59, 1868-1875]. Genetic and mutagenesis studies suggest that gyrase, which is the target for fluoroquinolone antibacterials, is also the target for MGIs. However, little is known regarding the interaction of these drugs with the bacterial type II enzyme. Therefore, we examined the effects of two MGIs, GSK000 and GSK325, on M. tuberculosis gyrase. MGIs greatly enhanced DNA cleavage mediated by the bacterial enzyme. In contrast to fluoroquinolones (which induce primarily double-stranded breaks), MGIs induced only single-stranded DNA breaks under a variety of conditions. MGIs work by stabilizing covalent gyrase-cleaved DNA complexes and appear to suppress the ability of the enzyme to induce double-stranded breaks. The drugs displayed little activity against type II topoisomerases from several other bacterial species, suggesting that these drugs display specificity for M. tuberculosis gyrase. Furthermore, MGIs maintained activity against M. tuberuclosis gyrase enzymes that contained the three most common fluoroquinolone resistance mutations seen in the clinic and displayed no activity against human topoisomerase IIα. These findings suggest that MGIs have potential as antitubercular drugs, especially in the case of fluoroquinolone-resistant disease.
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Affiliation(s)
| | - Tim R. Blower
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, United States
| | - Monica Cacho
- Department of Diseases of the Developing World, GlaxoSmithKline, Parque Tecnológico de Madrid, Calle de Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Ben Bax
- Medicines Discovery Institute, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - James M. Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2185, United States
| | - Neil Osheroff
- VA Tennessee Valley Healthcare System, Nashville, Tennessee 37212, United States
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25
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Wendorff TJ, Berger JM. Topoisomerase VI senses and exploits both DNA crossings and bends to facilitate strand passage. eLife 2018; 7:31724. [PMID: 29595473 PMCID: PMC5922973 DOI: 10.7554/elife.31724] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 03/28/2018] [Indexed: 01/09/2023] Open
Abstract
Type II topoisomerases manage DNA supercoiling and aid chromosome segregation using a complex, ATP-dependent duplex strand passage mechanism. Type IIB topoisomerases and their homologs support both archaeal/plant viability and meiotic recombination. Topo VI, a prototypical type IIB topoisomerase, comprises two Top6A and two Top6B protomers; how these subunits cooperate to engage two DNA segments and link ATP turnover to DNA transport is poorly understood. Using multiple biochemical approaches, we show that Top6B, which harbors the ATPase activity of topo VI, recognizes and exploits the DNA crossings present in supercoiled DNA to stimulate subunit dimerization by ATP. Top6B self-association in turn induces extensive DNA bending, which is needed to support duplex cleavage by Top6A. Our observations explain how topo VI tightly coordinates DNA crossover recognition and ATP binding with strand scission, providing useful insights into the operation of type IIB topoisomerases and related meiotic recombination and GHKL ATPase machineries. Each human cell contains genetic information stored on approximately two meters of DNA. Like holiday lights in a storage box, packing so much DNA into such a small space leads to its entanglement. This snarled DNA prevents the cell from properly accessing and copying its genes. Type II topoisomerases are a group of enzymes that remove DNA tangles. They attach to one segment of a DNA tangle, cut it in half, remove the knot, and then repair the broken DNA strand. The process requires the proteins to ‘burn’ chemical energy. If topoisomerases make mistakes when they cut and reseal DNA, they could damage genetic information and harm cells. It is still unclear how these proteins recognize DNA tangles and use energy to remove knots instead of adding them. Here, Wendorff and Berger use biochemical approaches to look into topo VI, a type II topoisomerase found in plants and certain single-celled organisms. When DNA is tangled, it forms sharp bends and crossings. Their experiments reveal that topo VI has certain ‘sensors’ that detect where DNA bends, and others that recognize the crossings. Only when both features are present does the enzyme start working and using energy. These sensors act as fail-safes to ensure that topo VI only breaks DNA when it encounters a proper knot, and is not ‘set loose’ on untangled DNA. Future work will look at topo VI at an atom-by-atom level to reveal how exactly the enzymes ‘see’ DNA bends and crossings, and how interactions with the correct type of DNA triggers energy use and DNA untangling. Knowing more about topo VI can help researchers to understand how human and bacterial topoisomerases work. These results could also be generalized to other enzymes, for example those that help the genetic processes at play when sperm and egg cells form.
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Affiliation(s)
- Timothy J Wendorff
- Biophysics Graduate Program, University of California, Berkeley, Berkeley, United States
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, United States
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26
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Ashley RE, Blower TR, Berger JM, Osheroff N. Recognition of DNA Supercoil Geometry by Mycobacterium tuberculosis Gyrase. Biochemistry 2017; 56:5440-5448. [PMID: 28921956 PMCID: PMC5637011 DOI: 10.1021/acs.biochem.7b00681] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
Mycobacterium
tuberculosis encodes only a single
type II topoisomerase, gyrase. As a result, this enzyme likely carries
out the cellular functions normally performed by canonical gyrase
and topoisomerase IV, both in front of and behind the replication
fork. In addition, it is the sole target for quinolone antibacterials
in this species. Because quinolone-induced DNA strand breaks generated
on positively supercoiled DNA ahead of replication forks and transcription
complexes are most likely to result in permanent genomic damage, the
actions of M. tuberculosis gyrase on positively supercoiled
DNA were investigated. Results indicate that the enzyme acts rapidly
on overwound DNA and removes positive supercoils much faster than
it introduces negative supercoils into relaxed DNA. Canonical gyrase
and topoisomerase IV distinguish supercoil handedness differently
during the DNA cleavage reaction: while gyrase maintains lower levels
of cleavage complexes on overwound DNA, topoisomerase IV maintains
similar levels of cleavage complexes on both over- and underwound
substrates. M. tuberculosis gyrase maintained lower
levels of cleavage complexes on positively supercoiled DNA in the
absence and presence of quinolone-based drugs. By retaining this important
feature of canonical gyrase, the dual function M. tuberculosis type II enzyme remains a safe enzyme to act in front of replication
forks and transcription complexes. Finally, the N-terminal gate region
of the enzyme appears to be necessary to distinguish supercoil handedness
during DNA cleavage, suggesting that the capture of the transport
segment may influence how gyrase maintains cleavage complexes on substrates
with different topological states.
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Affiliation(s)
| | - Tim R Blower
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine , Baltimore, Maryland 21205-2185, United States
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine , Baltimore, Maryland 21205-2185, United States
| | - Neil Osheroff
- VA Tennessee Valley Healthcare System , Nashville, Tennessee 37212, United States
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27
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Huang WC, Lee CY, Hsieh TS. Single-molecule Förster resonance energy transfer (FRET) analysis discloses the dynamics of the DNA-topoisomerase II (Top2) interaction in the presence of TOP2-targeting agents. J Biol Chem 2017. [PMID: 28630044 DOI: 10.1074/jbc.m117.792861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Topoisomerases play crucial roles in DNA replication, transcription, and recombination. For instance, topoisomerase II (Top2) is critically important for resolving DNA tangles during cell division, and as such, it is a broad anticancer drug target. Top2 regulates DNA topology by transiently breaking one double-stranded DNA molecule (cleavage), allowing a second double strand to pass through the opened DNA gate (opening), and then closing the gate by rejoining the broken ends. Drugs that modulate Top2 catalysis may therefore affect enzymatic activity at several different steps. Previous studies have focused on examining DNA cleavage and ligation; however, the dynamic opening and closing of the DNA gate has been less explored. Here, we used the single-molecule Förster resonance energy transfer (smFRET) method to observe the open and closed state of the DNA gate and to measure dwell times in each state. Our results show that Top2 binds and bends DNA to increase the energy transfer efficiency (EFRET), and ATP treatment further induces the fluctuation of EFRET, representing the gate opening and closing. Additionally, our results demonstrate that both types of Top2-targeting anticancer drugs, the catalytic inhibitor dexrazoxane (ICRF187) and mechanistic poison teniposide (VM26), can interfere with DNA gate dynamics and shorten the dwell time in the closed state. Moreover, Top2 bound to the nonhydrolyzable ATP analog 5'-adenylyl-β,γ-imidodiphosphate exhibits altered DNA gate dynamics, but the DNA gate appears to open and close even after N-gate closure. In summary, we have utilized single-molecule detection to unravel Top2 DNA gate dynamics and reveal previously unknown effects of Top2 drugs on these dynamics.
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Affiliation(s)
- Wan-Chen Huang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan.
| | - Chun-Ying Lee
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan; Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Tao-Shih Hsieh
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan; Department of Chemistry, National Taiwan University, Taipei 106, Taiwan; Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710
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28
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Jamieson GC, Fox JA, Poi M, Strickland SA. Molecular and Pharmacologic Properties of the Anticancer Quinolone Derivative Vosaroxin: A New Therapeutic Agent for Acute Myeloid Leukemia. Drugs 2017; 76:1245-1255. [PMID: 27484675 PMCID: PMC4989016 DOI: 10.1007/s40265-016-0614-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vosaroxin is a first-in-class anticancer quinolone derivative that targets topoisomerase II and induces site-selective double-strand breaks in DNA, leading to tumor cell apoptosis. Vosaroxin has chemical and pharmacologic characteristics distinct from other topoisomerase II inhibitors due to its quinolone scaffold. The efficacy and safety of vosaroxin in combination with cytarabine were evaluated in patients with relapsed/refractory acute myeloid leukemia (AML) in a phase III, randomized, multicenter, double-blind, placebo-controlled study (VALOR). In this study, the addition of vosaroxin produced a 1.4-month improvement in median overall survival (OS; 7.5 months with vosaroxin/cytarabine vs. 6.1 months with placebo/cytarabine; hazard ratio [HR] 0.87, 95 % confidence interval [CI] 0.73−1.02; unstratified log-rank p\documentclass[12pt]{minimal}
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\begin{document}$$=$$\end{document}= 0.039), two AML patient groups that typically have poor prognosis. Here we review the chemical and pharmacologic properties of vosaroxin, how these properties are distinct from those of currently available topoisomerase II inhibitors, how they may contribute to the efficacy and safety profile observed in the VALOR trial, and the status of clinical development of vosaroxin for treatment of AML.
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Affiliation(s)
| | - Judith A Fox
- Sunesis Pharmaceuticals, Inc., South San Francisco, CA, USA
| | - Ming Poi
- College of Pharmacy, Ohio State University, Columbus, OH, USA
| | - Stephen A Strickland
- Division of Hematology/Oncology, Department of Medicine, Vanderbilt University, 2220 Pierce Avenue, 777 Preston Research Building, Nashville, TN, 37232, USA.
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29
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Yu X, Davenport JW, Urtishak KA, Carillo ML, Gosai SJ, Kolaris CP, Byl JAW, Rappaport EF, Osheroff N, Gregory BD, Felix CA. Genome-wide TOP2A DNA cleavage is biased toward translocated and highly transcribed loci. Genome Res 2017; 27:1238-1249. [PMID: 28385713 PMCID: PMC5495075 DOI: 10.1101/gr.211615.116] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 04/05/2017] [Indexed: 01/22/2023]
Abstract
Type II topoisomerases orchestrate proper DNA topology, and they are the targets of anti-cancer drugs that cause treatment-related leukemias with balanced translocations. Here, we develop a high-throughput sequencing technology to define TOP2 cleavage sites at single-base precision, and use the technology to characterize TOP2A cleavage genome-wide in the human K562 leukemia cell line. We find that TOP2A cleavage has functionally conserved local sequence preferences, occurs in cleavage cluster regions (CCRs), and is enriched in introns and lincRNA loci. TOP2A CCRs are biased toward the distal regions of gene bodies, and TOP2 poisons cause a proximal shift in their distribution. We find high TOP2A cleavage levels in genes involved in translocations in TOP2 poison–related leukemia. In addition, we find that a large proportion of genes involved in oncogenic translocations overall contain TOP2A CCRs. The TOP2A cleavage of coding and lincRNA genes is independently associated with both length and transcript abundance. Comparisons to ENCODE data reveal distinct TOP2A CCR clusters that overlap with marks of transcription, open chromatin, and enhancers. Our findings implicate TOP2A cleavage as a broad DNA damage mechanism in oncogenic translocations as well as a functional role of TOP2A cleavage in regulating transcription elongation and gene activation.
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Affiliation(s)
- Xiang Yu
- Biology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - James W Davenport
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Karen A Urtishak
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Marie L Carillo
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Sager J Gosai
- Biology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Christos P Kolaris
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Jo Ann W Byl
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, USA
| | - Eric F Rappaport
- NAPCore, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | - Neil Osheroff
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, USA.,Department of Medicine (Hematology/Oncology), Vanderbilt University, Nashville, Tennessee 37232, USA.,VA Tennessee Valley Healthcare System, Nashville, Tennessee 37212, USA
| | - Brian D Gregory
- Biology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Carolyn A Felix
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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30
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Kamagata K, Murata A, Itoh Y, Takahashi S. Characterization of facilitated diffusion of tumor suppressor p53 along DNA using single-molecule fluorescence imaging. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2017. [DOI: 10.1016/j.jphotochemrev.2017.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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31
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Seol Y, Neuman KC. The dynamic interplay between DNA topoisomerases and DNA topology. Biophys Rev 2016; 8:101-111. [PMID: 28510219 DOI: 10.1007/s12551-016-0240-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/07/2016] [Indexed: 01/03/2023] Open
Abstract
Topological properties of DNA influence its structure and biochemical interactions. Within the cell, DNA topology is constantly in flux. Transcription and other essential processes, including DNA replication and repair, not only alter the topology of the genome but also introduce additional complications associated with DNA knotting and catenation. These topological perturbations are counteracted by the action of topoisomerases, a specialized class of highly conserved and essential enzymes that actively regulate the topological state of the genome. This dynamic interplay among DNA topology, DNA processing enzymes, and DNA topoisomerases is a pervasive factor that influences DNA metabolism in vivo. Building on the extensive structural and biochemical characterization over the past four decades that has established the fundamental mechanistic basis of topoisomerase activity, scientists have begun to explore the unique roles played by DNA topology in modulating and influencing the activity of topoisomerases. In this review we survey established and emerging DNA topology-dependent protein-DNA interactions with a focus on in vitro measurements of the dynamic interplay between DNA topology and topoisomerase activity.
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Affiliation(s)
- Yeonee Seol
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, 50 South Dr., Room 3517, Bethesda, MD, 20892, USA
| | - Keir C Neuman
- Laboratory of Single Molecule Biophysics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, 50 South Dr., Room 3517, Bethesda, MD, 20892, USA.
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32
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Gubaev A, Weidlich D, Klostermeier D. DNA gyrase with a single catalytic tyrosine can catalyze DNA supercoiling by a nicking-closing mechanism. Nucleic Acids Res 2016; 44:10354-10366. [PMID: 27557712 PMCID: PMC5137430 DOI: 10.1093/nar/gkw740] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 07/20/2016] [Accepted: 08/12/2016] [Indexed: 01/10/2023] Open
Abstract
The topological state of DNA is important for replication, recombination and transcription, and is regulated in vivo by DNA topoisomerases. Gyrase introduces negative supercoils into DNA at the expense of ATP hydrolysis. It is the accepted view that gyrase achieves supercoiling by a strand passage mechanism, in which double-stranded DNA is cleaved, and a second double-stranded segment is passed through the gap, converting a positive DNA node into a negative node. We show here that gyrase with only one catalytic tyrosine that cleaves a single strand of its DNA substrate can catalyze DNA supercoiling without strand passage. We propose an alternative mechanism for DNA supercoiling via nicking and closing of DNA that involves trapping, segregation and relaxation of two positive supercoils. In contrast to DNA supercoiling, ATP-dependent relaxation and decatenation of DNA by gyrase lacking the C-terminal domains require both tyrosines and strand passage. Our results point towards mechanistic plasticity of gyrase and might pave the way for finding novel and specific mechanism-based gyrase inhibitors.
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Affiliation(s)
- Airat Gubaev
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Daniela Weidlich
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- University of Muenster, Institute for Physical Chemistry, Corrensstrasse 30, D-48149 Muenster, Germany
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Abstract
Topological properties of DNA influence its structure and biochemical interactions. Within the cell DNA topology is constantly in flux. Transcription and other essential processes including DNA replication and repair, alter the topology of the genome, while introducing additional complications associated with DNA knotting and catenation. These topological perturbations are counteracted by the action of topoisomerases, a specialized class of highly conserved and essential enzymes that actively regulate the topological state of the genome. This dynamic interplay among DNA topology, DNA processing enzymes, and DNA topoisomerases, is a pervasive factor that influences DNA metabolism in vivo. Building on the extensive structural and biochemical characterization over the past four decades that established the fundamental mechanistic basis of topoisomerase activity, the unique roles played by DNA topology in modulating and influencing the activity of topoisomerases have begun to be explored. In this review we survey established and emerging DNA topology dependent protein-DNA interactions with a focus on in vitro measurements of the dynamic interplay between DNA topology and topoisomerase activity.
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Affiliation(s)
- Yeonee Seol
- Laboratory of Single Molecule Biophysics, NHLBI, National Institutes of Health, Bethesda, MD, 20892, U.S.A
| | - Keir C Neuman
- Laboratory of Single Molecule Biophysics, NHLBI, National Institutes of Health, Bethesda, MD, 20892, U.S.A
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The Current Case of Quinolones: Synthetic Approaches and Antibacterial Activity. Molecules 2016; 21:268. [PMID: 27043501 PMCID: PMC6274096 DOI: 10.3390/molecules21040268] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/08/2016] [Accepted: 02/15/2016] [Indexed: 11/17/2022] Open
Abstract
Quinolones are broad-spectrum synthetic antibacterial drugs first obtained during the synthesis of chloroquine. Nalidixic acid, the prototype of quinolones, first became available for clinical consumption in 1962 and was used mainly for urinary tract infections caused by Escherichia coli and other pathogenic Gram-negative bacteria. Recently, significant work has been carried out to synthesize novel quinolone analogues with enhanced activity and potential usage for the treatment of different bacterial diseases. These novel analogues are made by substitution at different sites--the variation at the C-6 and C-8 positions gives more effective drugs. Substitution of a fluorine atom at the C-6 position produces fluroquinolones, which account for a large proportion of the quinolones in clinical use. Among others, substitution of piperazine or methylpiperazine, pyrrolidinyl and piperidinyl rings also yields effective analogues. A total of twenty six analogues are reported in this review. The targets of quinolones are two bacterial enzymes of the class II topoisomerase family, namely gyrase and topoisomerase IV. Quinolones increase the concentration of drug-enzyme-DNA cleavage complexes and convert them into cellular toxins; as a result they are bactericidal. High bioavailability, relative low toxicity and favorable pharmacokinetics have resulted in the clinical success of fluoroquinolones and quinolones. Due to these superior properties, quinolones have been extensively utilized and this increased usage has resulted in some quinolone-resistant bacterial strains. Bacteria become resistant to quinolones by three mechanisms: (1) mutation in the target site (gyrase and/or topoisomerase IV) of quinolones; (2) plasmid-mediated resistance; and (3) chromosome-mediated quinolone resistance. In plasmid-mediated resistance, the efflux of quinolones is increased along with a decrease in the interaction of the drug with gyrase (topoisomerase IV). In the case of chromosome-mediated quinolone resistance, there is a decrease in the influx of the drug into the cell.
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Abstract
We study the elasticity of DNA based on local principal axes of bending identified from over 0.9-μs all-atom molecular dynamics simulations of DNA oligos. The calculated order parameters describe motion of DNA as an elastic rod. In 10 possible dinucleotide steps, bending about the two principal axes is anisotropic yet linearly elastic. Twist about the centroid axis is largely decoupled from bending, but DNA tends to overtwist for unbending beyond the typical range of thermal motion, which is consistent with experimentally observed twist-stretch coupling. The calculated elastic stiffness of dinucleotide steps yield sequence-dependent persistence lengths consistent with previous single-molecule experiments, which is further analyzed by performing coarse-grained simulations of DNA. Flexibility maps of oligos constructed from simulation also match with those from the precalculated stiffness of dinucleotide steps. These support the premise that base pair interaction at the dinucleotide-level is mainly responsible for the elasticity of DNA. Furthermore, we analyze 1381 crystal structures of protein-DNA complexes. In most structures, DNAs are mildly deformed and twist takes the highest portion of the total elastic energy. By contrast, in structures with the elastic energy per dinucleotide step greater than about 4.16 kBT (kBT: thermal energy), the major bending becomes dominant. The extensional energy of dinucleotide steps takes at most 35% of the total elastic energy except for structures containing highly deformed DNAs where linear elasticity breaks down. Such partitioning between different deformational modes provides quantitative insights into the conformational dynamics of DNA as well as its interaction with other molecules and surfaces.
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Affiliation(s)
- Xiaojing Teng
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843, United States
| | - Wonmuk Hwang
- Department of Biomedical Engineering, Texas A&M University , College Station, Texas 77843, United States
- Department of Materials Science and Engineering, Texas A&M University , College Station, Texas 77843, United States
- School of Computational Sciences, Korea Institute for Advanced Study , Seoul, Korea 02455
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36
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Singh V, Sharma K, Shankar B, Awasthi SK, Gupta RD. Heteroleptic Cu(ii)–polypyridyl complexes as photonucleases. NEW J CHEM 2016. [DOI: 10.1039/c6nj00409a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four new copper(ii)–polypyridyl complexes having tail groups with increasing aromaticity, hydrophobicity and planarity are synthesized. These complexes are found to be avid DNA binders and show efficient nuclease activity under either chemical stimulus or UV-A light irradiation.
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Affiliation(s)
- V. Singh
- Department of Chemistry
- University of Delhi
- Delhi-110 007
- India
- Department of Chemical Engineering
| | - K. Sharma
- Department of Chemistry
- University of Delhi
- Delhi-110 007
- India
| | - B. Shankar
- Department of Chemistry
- University of Delhi
- Delhi-110 007
- India
| | - S. K. Awasthi
- Department of Chemistry
- University of Delhi
- Delhi-110 007
- India
| | - R. D. Gupta
- Faculty of Life Sciences and Biotechnology
- South Asian University
- Delhi-110 021
- India
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37
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Oppegard LM, Schwanz HA, Towle TR, Kerns RJ, Hiasa H. Fluoroquinolones stimulate the DNA cleavage activity of topoisomerase IV by promoting the binding of Mg(2+) to the second metal binding site. Biochim Biophys Acta Gen Subj 2015; 1860:569-75. [PMID: 26723176 DOI: 10.1016/j.bbagen.2015.12.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/14/2015] [Accepted: 12/22/2015] [Indexed: 01/03/2023]
Abstract
BACKGROUND Fluoroquinolones target bacterial type IIA topoisomerases, DNA gyrase and topoisomerase IV (Topo IV). Fluoroquinolones trap a topoisomerase-DNA covalent complex as a topoisomerase-fluoroquinolone-DNA ternary complex and ternary complex formation is critical for their cytotoxicity. A divalent metal ion is required for type IIA topoisomerase-catalyzed strand breakage and religation reactions. Recent studies have suggested that type IIA topoisomerases use two metal ions, one structural and one catalytic, to carry out the strand breakage reaction. METHODS We conducted a series of DNA cleavage assays to examine the effects of fluoroquinolones and quinazolinediones on Mg(2+)-, Mn(2+)-, or Ca(2+)-supported DNA cleavage activity of Escherichia coli Topo IV. RESULTS In the absence of any drug, 20-30 mM Mg(2+) was required for the maximum levels of the DNA cleavage activity of Topo IV, whereas approximately 1mM of either Mn(2+) or Ca(2+) was sufficient to support the maximum levels of the DNA cleavage activity of Topo IV. Fluoroquinolones promoted the Topo IV-catalyzed strand breakage reaction at low Mg(2+) concentrations where Topo IV alone could not efficiently cleave DNA. CONCLUSIONS AND GENERAL SIGNIFICANCE At low Mg(2+) concentrations, fluoroquinolones may stimulate the Topo IV-catalyzed strand breakage reaction by promoting Mg(2+) binding to metal binding site B through the structural distortion in DNA. As Mg(2+) concentration increases, fluoroquinolones may inhibit the religation reaction by either stabilizing Mg(2+) at site B or inhibition the binding of Mg(2+) to site A. This study provides a molecular basis of how fluoroquinolones stimulate the Topo IV-catalyzed strand breakage reaction by modulating Mg(2+) binding.
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Affiliation(s)
- Lisa M Oppegard
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA.
| | - Heidi A Schwanz
- Division of Medicinal and Natural Products Chemistry, Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, 115 S Grand Ave., S321 Pharmacy Building, Iowa City, IA 52242, USA.
| | - Tyrell R Towle
- Division of Medicinal and Natural Products Chemistry, Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, 115 S Grand Ave., S321 Pharmacy Building, Iowa City, IA 52242, USA.
| | - Robert J Kerns
- Division of Medicinal and Natural Products Chemistry, Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, 115 S Grand Ave., S321 Pharmacy Building, Iowa City, IA 52242, USA.
| | - Hiroshi Hiasa
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA.
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38
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Huang NL, Lin JH. Recovery of the poisoned topoisomerase II for DNA religation: coordinated motion of the cleavage core revealed with the microsecond atomistic simulation. Nucleic Acids Res 2015; 43:6772-86. [PMID: 26150421 PMCID: PMC4538842 DOI: 10.1093/nar/gkv672] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/19/2015] [Indexed: 01/24/2023] Open
Abstract
Type II topoisomerases resolve topological problems of DNA double helices by passing one duplex through the reversible double-stranded break they generated on another duplex. Despite the wealth of information in the cleaving operation, molecular understanding of the enzymatic DNA ligation remains elusive. Topoisomerase poisons are widely used in anti-cancer and anti-bacterial therapy and have been employed to entrap the intermediates of topoisomerase IIβ with religatable DNA substrate. We removed drug molecules from the structure and conducted molecular dynamics simulations to investigate the enzyme-mediated DNA religation. The drug-unbound intermediate displayed transitions toward the resealing-compliant configuration: closing distance between the cleaved DNA termini, B-to-A transformation of the double helix, and restoration of the metal-binding motif. By mapping the contact configurations and the correlated motions between enzyme and DNA, we identified the indispensable role of the linker preceding winged helix domain (WHD) in coordinating the movements of TOPRIM, the nucleotide-binding motifs, and the bound DNA substrate during gate closure. We observed a nearly vectorial transition in the recovery of the enzyme and identified the previously uncharacterized roles of Asn508 and Arg677 in DNA rejoining. Our findings delineate the dynamic mechanism of the DNA religation conducted by type II topoisomerases.
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Affiliation(s)
- Nan-Lan Huang
- Research Center for Applied Sciences, Academia Sinica, Nangang, Taipei 11529, Taiwan
| | - Jung-Hsin Lin
- Research Center for Applied Sciences, Academia Sinica, Nangang, Taipei 11529, Taiwan Institute of Biomedical Sciences, Academia Sinica, Nangang, Taipei 11529, Taiwan School of Pharmacy, National Taiwan University, Taipei 10050, Taiwan
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Kristoffersen EL, Jørgensen LA, Franch O, Etzerodt M, Frøhlich R, Bjergbæk L, Stougaard M, Ho YP, Knudsen BR. Real-time investigation of human topoisomerase I reaction kinetics using an optical sensor: a fast method for drug screening and determination of active enzyme concentrations. NANOSCALE 2015; 7:9825-9834. [PMID: 25963854 DOI: 10.1039/c5nr01474c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Human DNA topoisomerase I (hTopI) is a nuclear enzyme that catalyzes relaxation of super helical tension that arises in the genome during essential DNA metabolic processes. This is accomplished through a common reaction mechanism shared among the type IB topoisomerase enzymes, including eukaryotic and poxvirus topoisomerase I. The mechanism of hTopI is specifically targeted in cancer treatment using camptothecin derivatives. These drugs convert the hTopI activity into a cellular poison, and hence the cytotoxic effects of camptothecin derivatives correlate with the hTopI activity. Therefore, fast and reliable techniques for high throughput measurements of hTopI activity are of high clinical interest. Here we demonstrate potential applications of a fluorophore-quencher based DNA sensor designed for measurement of hTopI cleavage-ligation activities, which are the catalytic steps affected by camptothecin. The kinetic analysis of the hTopI reaction with the DNA sensor exhibits a characteristic burst profile. This is the result of a two-step ping-pong reaction mechanism, where a fast first reaction, the one creating the signal, is followed by a slower second reaction necessary for completion of the catalytic cycle. Hence, the burst profile holds information about two reactions in the enzymatic mechanism. Moreover, it allows the amount of active enzyme in the reaction to be determined. The presented results pave the way for future high throughput drug screening and the potential of measuring active hTopI concentrations in clinical samples for individualized treatment.
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40
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Baranello L, Kouzine F, Levens D. DNA topoisomerases beyond the standard role. Transcription 2015; 4:232-7. [PMID: 24135702 DOI: 10.4161/trns.26598] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Chromatin is dynamically changing its structure to accommodate and control DNA-dependent processes inside of eukaryotic cells. These changes are necessarily linked to changes of DNA topology, which might itself serve as a regulatory signal to be detected by proteins. Thus, DNA Topoisomerases may contribute to the regulation of many events occurring during the transcription cycle. In this review we will focus on DNA Topoisomerase functions in transcription, with particular emphasis on the multiplicity of tasks beyond their widely appreciated role in solving topological problems associated with transcription elongation.
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41
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Lindsey RH, Pendleton M, Ashley RE, Mercer SL, Deweese JE, Osheroff N. Catalytic core of human topoisomerase IIα: insights into enzyme-DNA interactions and drug mechanism. Biochemistry 2014; 53:6595-602. [PMID: 25280269 PMCID: PMC4204876 DOI: 10.1021/bi5010816] [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]
Abstract
Coordination between the N-terminal gate and the catalytic core of topoisomerase II allows the proper capture, cleavage, and transport of DNA during the catalytic cycle. Because the activities of these domains are tightly linked, it has been difficult to discern their individual contributions to enzyme-DNA interactions and drug mechanism. To further address the roles of these domains, we analyzed the activity of the catalytic core of human topoisomerase IIα. The catalytic core and the wild-type enzyme both maintained higher levels of cleavage with negatively (as compared to positively) supercoiled plasmid, indicating that the ability to distinguish supercoil handedness is embedded within the catalytic core. However, the catalytic core alone displayed little ability to cleave DNA substrates that did not intrinsically provide the enzyme with a transport segment (i.e., substrates that did not contain crossovers). Finally, in contrast to interfacial topoisomerase II poisons, covalent poisons did not enhance DNA cleavage mediated by the catalytic core. This distinction allowed us to further characterize the mechanism of etoposide quinone, a drug metabolite that functions primarily as a covalent poison. Etoposide quinone retained some ability to enhance DNA cleavage mediated by the catalytic core, indicating that it still can function as an interfacial poison. These results further define the distinct contributions of the N-terminal gate and the catalytic core to topoisomerase II function. The catalytic core senses the handedness of DNA supercoils during cleavage, while the N-terminal gate is critical for capturing the transport segment and for the activity of covalent poisons.
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Affiliation(s)
- R Hunter Lindsey
- Department of Biochemistry, ‡Department of Pharmacology, and §Department of Medicine (Hematology/Oncology), Vanderbilt University School of Medicine , Nashville, Tennessee 37232-0146, United States
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42
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Gubaev A, Klostermeier D. Reprint of "The mechanism of negative DNA supercoiling: a cascade of DNA-induced conformational changes prepares gyrase for strand passage". DNA Repair (Amst) 2014; 20:130-141. [PMID: 24974097 DOI: 10.1016/j.dnarep.2014.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/03/2014] [Accepted: 01/13/2014] [Indexed: 01/04/2023]
Abstract
DNA topoisomerases inter-convert different DNA topoisomers in the cell. They catalyze the introduction or relaxation of DNA supercoils, as well as catenation and decatenation. Members of the type I topoisomerase family cleave a single strand of their double-stranded DNA substrate, whereas enzymes of the type II family cleave both DNA strands. Bacterial DNA gyrase, a type II topoisomerase, catalyzes the introduction of negative supercoils into DNA in an ATP-dependent reaction. Gyrase is not present in humans, and constitutes an attractive drug target for the treatment of bacterial and parasite infections. DNA supercoiling by gyrase is believed to occur by a strand passage mechanism, in which one segment of the double-stranded DNA substrate is passed through a (transient) break in a second segment. This mechanism requires the coordinated opening and closing of three protein interfaces, so-called gates, to ensure the directionality of strand passage toward negative supercoiling. Single molecule fluorescence resonance energy transfer experiments are ideally suited to investigate conformational changes during the catalytic cycle of DNA topoisomerases. In this review, we summarize the current knowledge on the cascade of DNA- and nucleotide-induced conformational changes in gyrase that lead to strand passage and negative supercoiling of DNA. We discuss how these conformational changes couple ATP hydrolysis to DNA supercoiling in gyrase, and how the common mechanistic principle of coordinated gate opening and closing is modulated to allow for the catalysis of different reactions by different type II topoisomerases.
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Affiliation(s)
- Airat Gubaev
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany.
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43
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Zhang H, Zhang YW, Yasukawa T, Dalla Rosa I, Khiati S, Pommier Y. Increased negative supercoiling of mtDNA in TOP1mt knockout mice and presence of topoisomerases IIα and IIβ in vertebrate mitochondria. Nucleic Acids Res 2014; 42:7259-67. [PMID: 24803675 PMCID: PMC4066791 DOI: 10.1093/nar/gku384] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Topoisomerases are critical for replication, DNA packing and repair, as well as for transcription by allowing changes in DNA topology. Cellular DNA is present both in nuclei and mitochondria, and mitochondrial topoisomerase I (Top1mt) is the only DNA topoisomerase specific for mitochondria in vertebrates. Here, we report in detail the generation of TOP1mt knockout mice, and demonstrate that mitochondrial DNA (mtDNA) displays increased negative supercoiling in TOP1mt knockout cells and murine tissues. This finding suggested imbalanced topoisomerase activity in the absence of Top1mt and the activity of other topoisomerases in mitochondria. Accordingly, we found that both Top2α and Top2β are present and active in mouse and human mitochondria. The presence of Top2α-DNA complexes in the mtDNA D-loop region, at the sites where both ends of 7S DNA are positioned, suggests a structural role for Top2 in addition to its classical topoisomerase activities.
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Affiliation(s)
- Hongliang Zhang
- Laboratory of Molecular Pharmacology and Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Yong-Wei Zhang
- Laboratory of Molecular Pharmacology and Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Takehiro Yasukawa
- The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Ilaria Dalla Rosa
- Laboratory of Molecular Pharmacology and Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Salim Khiati
- Laboratory of Molecular Pharmacology and Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Yves Pommier
- Laboratory of Molecular Pharmacology and Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
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Lymphohematopoietic cancers induced by chemicals and other agents and their implications for risk evaluation: An overview. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 761:40-64. [PMID: 24731989 DOI: 10.1016/j.mrrev.2014.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 12/13/2022]
Abstract
Lymphohematopoietic neoplasia are one of the most common types of cancer induced by therapeutic and environmental agents. Of the more than 100 human carcinogens identified by the International Agency for Research on Cancer, approximately 25% induce leukemias or lymphomas. The objective of this review is to provide an introduction into the origins and mechanisms underlying lymphohematopoietic cancers induced by xenobiotics in humans with an emphasis on acute myeloid leukemia, and discuss the implications of this information for risk assessment. Among the agents causing lymphohematopoietic cancers, a number of patterns were observed. Most physical and chemical leukemia-inducing agents such as the therapeutic alkylating agents, topoisomerase II inhibitors, and ionizing radiation induce mainly acute myeloid leukemia through DNA-damaging mechanisms that result in either gene or chromosomal mutations. In contrast, biological agents and a few immunosuppressive chemicals induce primarily lymphoid neoplasms through mechanisms that involve alterations in immune response. Among the environmental agents examined, benzene was clearly associated with acute myeloid leukemia in humans, with increasing but still limited evidence for an association with lymphoid neoplasms. Ethylene oxide and 1,3-butadiene were linked primarily to lymphoid cancers. Although the association between formaldehyde and leukemia remains controversial, several recent evaluations have indicated a potential link between formaldehyde and acute myeloid leukemia. The four environmental agents examined in detail were all genotoxic, inducing gene mutations, chromosomal alterations, and/or micronuclei in vivo. Although it is clear that rapid progress has been made in recent years in our understanding of leukemogenesis, many questions remain for future research regarding chemically induced leukemias and lymphomas, including the mechanisms by which the environmental agents reviewed here induce these diseases and the risks associated with exposures to such agents.
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45
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Farooq S, Fijen C, Hohlbein J. Studying DNA-protein interactions with single-molecule Förster resonance energy transfer. PROTOPLASMA 2014; 251:317-32. [PMID: 24374460 DOI: 10.1007/s00709-013-0596-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 05/21/2023]
Abstract
Single-molecule Förster resonance energy transfer (smFRET) has emerged as a powerful tool for elucidating biological structure and mechanisms on the molecular level. Here, we focus on applications of smFRET to study interactions between DNA and enzymes such as DNA and RNA polymerases. SmFRET, used as a nanoscopic ruler, allows for the detection and precise characterisation of dynamic and rarely occurring events, which are otherwise averaged out in ensemble-based experiments. In this review, we will highlight some recent developments that provide new means of studying complex biological systems either by combining smFRET with force-based techniques or by using data obtained from smFRET experiments as constrains for computer-aided modelling.
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Affiliation(s)
- Shazia Farooq
- Laboratory of Biophysics, Wageningen UR, Wageningen, The Netherlands
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Ketron AC, Osheroff N. Phytochemicals as Anticancer and Chemopreventive Topoisomerase II Poisons. PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2014; 13:19-35. [PMID: 24678287 PMCID: PMC3963363 DOI: 10.1007/s11101-013-9291-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Phytochemicals are a rich source of anticancer drugs and chemopreventive agents. Several of these chemicals appear to exert at least some of their effects through interactions with topoisomerase II, an essential enzyme that regulates DNA supercoiling and removes knots and tangles from the genome. Topoisomerase II-active phytochemicals function by stabilizing covalent protein-cleaved DNA complexes that are intermediates in the catalytic cycle of the enzyme. As a result, these compounds convert topoisomerase II to a cellular toxin that fragments the genome. Because of their mode of action, they are referred to as topoisomerase II poisons as opposed to catalytic inhibitors. The first sections of this article discuss DNA topology, the catalytic cycle of topoisomerase II, and the two mechanisms (interfacial vs. covalent) by which different classes of topoisomerase II poisons alter enzyme activity. Subsequent sections discuss the effects of several phytochemicals on the type II enzyme, including demethyl-epipodophyllotoxins (semisynthetic anticancer drugs) as well as flavones, flavonols, isoflavones, catechins, isothiocyanates, and curcumin (dietary chemopreventive agents). Finally, the leukemogenic potential of topoisomerase II-targeted phytochemicals is described.
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Affiliation(s)
- Adam C. Ketron
- Department of Biochemistry and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 USA
| | - Neil Osheroff
- Departments of Biochemistry and Medicine (Hematology/Oncology) and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 USA
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47
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Gubaev A, Klostermeier D. The mechanism of negative DNA supercoiling: a cascade of DNA-induced conformational changes prepares gyrase for strand passage. DNA Repair (Amst) 2014; 16:23-34. [PMID: 24674625 DOI: 10.1016/j.dnarep.2014.01.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/03/2014] [Accepted: 01/13/2014] [Indexed: 11/29/2022]
Abstract
DNA topoisomerases inter-convert different DNA topoisomers in the cell. They catalyze the introduction or relaxation of DNA supercoils, as well as catenation and decatenation. Members of the type I topoisomerase family cleave a single strand of their double-stranded DNA substrate, whereas enzymes of the type II family cleave both DNA strands. Bacterial DNA gyrase, a type II topoisomerase, catalyzes the introduction of negative supercoils into DNA in an ATP-dependent reaction. Gyrase is not present in humans, and constitutes an attractive drug target for the treatment of bacterial and parasite infections. DNA supercoiling by gyrase is believed to occur by a strand passage mechanism, in which one segment of the double-stranded DNA substrate is passed through a (transient) break in a second segment. This mechanism requires the coordinated opening and closing of three protein interfaces, so-called gates, to ensure the directionality of strand passage toward negative supercoiling. Single molecule fluorescence resonance energy transfer experiments are ideally suited to investigate conformational changes during the catalytic cycle of DNA topoisomerases. In this review, we summarize the current knowledge on the cascade of DNA- and nucleotide-induced conformational changes in gyrase that lead to strand passage and negative supercoiling of DNA. We discuss how these conformational changes couple ATP hydrolysis to DNA supercoiling in gyrase, and how the common mechanistic principle of coordinated gate opening and closing is modulated to allow for the catalysis of different reactions by different type II topoisomerases.
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Affiliation(s)
- Airat Gubaev
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany
| | - Dagmar Klostermeier
- Institute for Physical Chemistry, University of Muenster, Corrensstrasse 30, D-48149 Muenster, Germany.
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48
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Pendleton M, Lindsey RH, Felix CA, Grimwade D, Osheroff N. Topoisomerase II and leukemia. Ann N Y Acad Sci 2014; 1310:98-110. [PMID: 24495080 DOI: 10.1111/nyas.12358] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type II topoisomerases are essential enzymes that modulate DNA under- and overwinding, knotting, and tangling. Beyond their critical physiological functions, these enzymes are the targets for some of the most widely prescribed anticancer drugs (topoisomerase II poisons) in clinical use. Topoisomerase II poisons kill cells by increasing levels of covalent enzyme-cleaved DNA complexes that are normal reaction intermediates. Drugs such as etoposide, doxorubicin, and mitoxantrone are frontline therapies for a variety of solid tumors and hematological malignancies. Unfortunately, their use also is associated with the development of specific leukemias. Regimens that include etoposide or doxorubicin are linked to the occurrence of acute myeloid leukemias that feature rearrangements at chromosomal band 11q23. Similar rearrangements are seen in infant leukemias and are associated with gestational diets that are high in naturally occurring topoisomerase II-active compounds. Finally, regimens that include mitoxantrone and epirubicin are linked to acute promyelocytic leukemias that feature t(15;17) rearrangements. The first part of this article will focus on type II topoisomerases and describe the mechanism of enzyme and drug action. The second part will discuss how topoisomerase II poisons trigger chromosomal breaks that lead to leukemia and potential approaches for dissociating the actions of drugs from their leukemogenic potential.
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Affiliation(s)
- Maryjean Pendleton
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee
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49
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Arnoldi E, Pan XS, Fisher LM. Functional determinants of gate-DNA selection and cleavage by bacterial type II topoisomerases. Nucleic Acids Res 2013; 41:9411-23. [PMID: 23939623 PMCID: PMC3814380 DOI: 10.1093/nar/gkt696] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Antibacterial fluoroquinolones trap a cleavage complex of gyrase and topoisomerase (topo) IV inducing site-specific DNA breakage within a bent DNA gate engaged in DNA transport. Despite its importance for drug action and in revealing potential sites of topoisomerase catalysis, the mechanism of DNA selectivity is poorly understood. To explore its functional basis, we generated mutant versions of the strongly cleaved E-site and used a novel competitive assay to examine their gemifloxacin-mediated DNA breakage by Streptococcus pneumoniae topo IV and gyrase. Parallel studies of Ca2+-induced cleavage distinguished ‘intrinsic recognition’ of DNA cleavage sites by topo IV from drug-induced preferences. Analysis revealed strong enzyme-determined requirements for −4G, −2A and −1T bases preceding the breakage site (between −1 and +1) and enzyme-unique or degenerate determinants at −3, plus drug-specific preferences at +2/+3 and for +1 purines associated with drug intercalation. Similar cleavage rules were seen additionally at the novel V-site identified here in ColE1-derived plasmids. In concert with DNA binding data, our results provide functional evidence for DNA, enzyme and drug contributions to DNA cleavage at the gate, suggest a mechanism for DNA discrimination involving enzyme-induced DNA bending/helix distortion and cleavage complex stabilization and advance understanding of fluoroquinolones as important cleavage-enhancing therapeutics.
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Affiliation(s)
- Elisa Arnoldi
- Division of Biomedical Sciences, St.George's, University of London, London SW17 0RE, UK
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Vos SM, Lee I, Berger JM. Distinct regions of the Escherichia coli ParC C-terminal domain are required for substrate discrimination by topoisomerase IV. J Mol Biol 2013; 425:3029-45. [PMID: 23867279 DOI: 10.1016/j.jmb.2013.04.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/14/2013] [Accepted: 04/16/2013] [Indexed: 11/16/2022]
Abstract
Type IIA DNA topoisomerases are essential enzymes that use ATP to maintain chromosome supercoiling and remove links between sister chromosomes. In Escherichia coli, the type IIA topoisomerase topo IV rapidly removes positive supercoils and catenanes from DNA but is significantly slower when confronted with negatively supercoiled substrates. The ability of topo IV to discriminate between positively and negatively supercoiled DNA requires the C-terminal domain (CTD) of one of its two subunits, ParC. To determine how the ParC CTD might assist with substrate discrimination, we identified potential DNA interacting residues on the surface of the CTD, mutated these residues, and tested their effect on both topo IV enzymatic activity and DNA binding by the isolated domain. Surprisingly, different regions of the ParC CTD do not bind DNA equivalently, nor contribute equally to the action of topo IV on different types of DNA substrates. Moreover, we find that the CTD contains an autorepressive element that inhibits activity on negatively supercoiled and catenated substrates, as well as a distinct region that aids in bending the DNA duplex that tracks through the enzyme's nucleolytic center. Our data demonstrate that the CTD is essential for proper engagement of both gate and transfer segment DNAs, reconciling different models to explain how topo IV discriminates between distinct DNAs topologies.
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Affiliation(s)
- Seychelle M Vos
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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