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Fijen C, Drogalis Beckham L, Terino D, Li Y, Ramsden DA, Wood RD, Doublié S, Rothenberg E. Sequential requirements for distinct Polθ domains during theta-mediated end joining. Mol Cell 2024; 84:1460-1474.e6. [PMID: 38640894 PMCID: PMC11031631 DOI: 10.1016/j.molcel.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 01/10/2024] [Accepted: 03/12/2024] [Indexed: 04/21/2024]
Abstract
DNA polymerase θ (Polθ) plays a central role in a DNA double-strand break repair pathway termed theta-mediated end joining (TMEJ). TMEJ functions by pairing short-sequence "microhomologies" (MHs) in single-stranded DNA at each end of a break and subsequently initiating DNA synthesis. It is not known how the Polθ helicase domain (HD) and polymerase domain (PD) operate to bring together MHs and facilitate repair. To resolve these transient processes in real time, we utilized in vitro single-molecule FRET approaches and biochemical analyses. We find that the Polθ-HD mediates the initial capture of two ssDNA strands, bringing them in close proximity. The Polθ-PD binds and stabilizes pre-annealed MHs to form a synaptic complex (SC) and initiate repair synthesis. Individual synthesis reactions show that Polθ is inherently non-processive, accounting for complex mutational patterns during TMEJ. Binding of Polθ-PD to stem-loop-forming sequences can substantially limit synapsis, depending on the available dNTPs and sequence context.
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Affiliation(s)
- Carel Fijen
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
| | - Lea Drogalis Beckham
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - Dante Terino
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Yuzhen Li
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77230, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77230, USA
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
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2
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Matveeva K, Vasilieva M, Minskaia E, Rybtsov S, Shevyrev D. T-cell immunity against senescence: potential role and perspectives. Front Immunol 2024; 15:1360109. [PMID: 38504990 PMCID: PMC10948549 DOI: 10.3389/fimmu.2024.1360109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/19/2024] [Indexed: 03/21/2024] Open
Abstract
The development of age-associated diseases is related to the accumulation of senescent cells in the body. These are old non-functional cells with impaired metabolism, which are unable to divide. Such cells are also resistant to programmed cell death and prone to spontaneous production of some inflammatory factors. The accumulation of senescent cells is related to the age-associated dysfunction of organs and tissues as well as chronic inflammation that enhances with age. In the young organism, senescent cells are removed with the innate immunity system. However, the efficiency of this process decreases with age. Nowadays, more and more evidences are accumulating to support the involvement of specific immunity and T-lymphocytes in the fight against senescent cells. It has great physiological importance since the efficient elimination of senescent cells requires a high diversity of antigen-recognizing receptors to cover the entire spectrum of senescent-associated antigens with high precision and specificity. Developing the approaches of T-cell immunity stimulation to generate or amplify a physiological immune response against senescent cells can provide new perspectives to extend active longevity. In this mini-review, the authors summarize the current understanding of the role of T-cell immunity in the fight against senescent cells and discuss the prospects of stimulating adaptive immunity for combating the accumulation of senescent cells that occurs with age.
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3
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Jia X, Kullik GA, Bufano M, Brancale A, Schols D, Meier C. Membrane-permeable tenofovir-di- and monophosphate analogues. Eur J Med Chem 2024; 264:116020. [PMID: 38086193 DOI: 10.1016/j.ejmech.2023.116020] [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: 11/12/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 12/30/2023]
Abstract
The development of new antiviral agents such as nucleoside analogues or acyclic nucleotide analogues (ANPs) and prodrugs thereof is an ongoing task. We report on the synthesis of three types of lipophilic triphosphate analogues of (R)-PMPA and dialkylated diphosphate analogues of (R)-PMPA. A highly selective release of the different nucleotide analogues ((R)-PMPA-DP, (R)-PMPA-MP, and (R)-PMPA) from these compounds was achieved. All dialkylated (R)-PMPA-prodrugs proved to be very stable in PBS as well as in CEM/0 cell extracts and human plasma. In primer extension assays, both the monoalkylated and the dialkylated (R)-PMPA-DP derivatives acted as (R)-PMPA-DP as a substrate for HIV-RT. In contrast, no incorporation events were observed using human polymerase γ. The dialkylated (R)-PMPA-compounds exhibited significant anti-HIV efficacy in HIV-1/2 infected cells (CEM/0 and CEM/TK-). Remarkably, the dialkylated (R)-PMPA-MP derivative 9a showed a 326-fold improved activity as compared to (R)-PMPA in HIV-2 infected CEM/TK- cells as well as a very high SI of 14,000. We are convinced that this study may significantly contribute to advancing antiviral agents developed based on nucleotide analogues in the future.
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Affiliation(s)
- Xiao Jia
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany
| | - Giuliano A Kullik
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany
| | - Marianna Bufano
- Dipartimento Chimica e Tecnologie del Farmaco, Facoltà di Farmacia e Medicina, University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Andrea Brancale
- Department of Organic Chemistry, Vysoká Škola Chemicko-Technologická v Praze, Technická 5, 16628, Prague, Czech Republic
| | - Dominique Schols
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Herestraat 49, B-3000, Leuven, Belgium
| | - Chris Meier
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany; Centre for Structural Systems Biology (CSSB), Hamburg, DESY Campus, Notkestrasse 85, D-22607, Hamburg, Germany.
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4
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Han S, Lu Y. Fluorine in anti-HIV drugs approved by FDA from 1981 to 2023. Eur J Med Chem 2023; 258:115586. [PMID: 37393791 DOI: 10.1016/j.ejmech.2023.115586] [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: 04/11/2023] [Revised: 06/17/2023] [Accepted: 06/20/2023] [Indexed: 07/04/2023]
Abstract
Human immunodeficiency virus (HIV) is the etiological agent of acquired immunodeficiency syndrome (AIDS). Nowadays, FDA has approved over thirty antiretroviral drugs grouped in six categories. Interestingly, one-third of these drugs contain different number of fluorine atoms. The introduction of fluorine to obtain drug-like compounds is a well-accepted strategy in medicinal chemistry. In this review, we summarized 11 fluorine-containing anti-HIV drugs, focusing on their efficacy, resistance, safety, and specific roles of fluorine in the development of each drug. These examples may be of help for the discovery of new drug candidates bearing fluorine in their structures.
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Affiliation(s)
- Sheng Han
- School of Medicine, Shanghai University, Shanghai, China.
| | - Yiming Lu
- School of Medicine, Shanghai University, Shanghai, China; Department of Critical Care Medicine, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.
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5
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Park J, Herrmann GK, Mitchell PG, Sherman MB, Yin YW. Polγ coordinates DNA synthesis and proofreading to ensure mitochondrial genome integrity. Nat Struct Mol Biol 2023; 30:812-823. [PMID: 37202477 PMCID: PMC10920075 DOI: 10.1038/s41594-023-00980-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 03/28/2023] [Indexed: 05/20/2023]
Abstract
Accurate replication of mitochondrial DNA (mtDNA) by DNA polymerase γ (Polγ) is essential for maintaining cellular energy supplies, metabolism, and cell cycle control. To illustrate the structural mechanism for Polγ coordinating polymerase (pol) and exonuclease (exo) activities to ensure rapid and accurate DNA synthesis, we determined four cryo-EM structures of Polγ captured after accurate or erroneous incorporation to a resolution of 2.4-3.0 Å. The structures show that Polγ employs a dual-checkpoint mechanism to sense nucleotide misincorporation and initiate proofreading. The transition from replication to error editing is accompanied by increased dynamics in both DNA and enzyme, in which the polymerase relaxes its processivity and the primer-template DNA unwinds, rotates, and backtracks to shuttle the mismatch-containing primer terminus 32 Å to the exo site for editing. Our structural and functional studies also provide a foundation for analyses of Polγ mutation-induced human diseases and aging.
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Affiliation(s)
- Joon Park
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Geoffrey K Herrmann
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Patrick G Mitchell
- Division of CryoEM and Bioimaging, Stanford Synchrotron Radiation Lightsource, Stanford Linear Accelerator Center National Accelerator Laboratory, Stanford University, Menlo Park, CA, USA
| | - Michael B Sherman
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Y Whitney Yin
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA.
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6
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Plaza-G A I, Lemishko KM, Crespo R, Truong TQ, Kaguni LS, Cao-García FJ, Ciesielski GL, Ibarra B. Mechanism of strand displacement DNA synthesis by the coordinated activities of human mitochondrial DNA polymerase and SSB. Nucleic Acids Res 2023; 51:1750-1765. [PMID: 36744436 PMCID: PMC9976888 DOI: 10.1093/nar/gkad037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/16/2022] [Accepted: 01/12/2023] [Indexed: 02/07/2023] Open
Abstract
Many replicative DNA polymerases couple DNA replication and unwinding activities to perform strand displacement DNA synthesis, a critical ability for DNA metabolism. Strand displacement is tightly regulated by partner proteins, such as single-stranded DNA (ssDNA) binding proteins (SSBs) by a poorly understood mechanism. Here, we use single-molecule optical tweezers and biochemical assays to elucidate the molecular mechanism of strand displacement DNA synthesis by the human mitochondrial DNA polymerase, Polγ, and its modulation by cognate and noncognate SSBs. We show that Polγ exhibits a robust DNA unwinding mechanism, which entails lowering the energy barrier for unwinding of the first base pair of the DNA fork junction, by ∼55%. However, the polymerase cannot prevent the reannealing of the parental strands efficiently, which limits by ∼30-fold its strand displacement activity. We demonstrate that SSBs stimulate the Polγ strand displacement activity through several mechanisms. SSB binding energy to ssDNA additionally increases the destabilization energy at the DNA junction, by ∼25%. Furthermore, SSB interactions with the displaced ssDNA reduce the DNA fork reannealing pressure on Polγ, in turn promoting the productive polymerization state by ∼3-fold. These stimulatory effects are enhanced by species-specific functional interactions and have significant implications in the replication of the human mitochondrial DNA.
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Affiliation(s)
- Ismael Plaza-G A
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Faraday 9, 28049 Madrid, Spain
| | - Kateryna M Lemishko
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Faraday 9, 28049 Madrid, Spain
| | - Rodrigo Crespo
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
| | - Thinh Q Truong
- Department of Chemistry, Auburn University at Montgomery, Montgomery, AL 36117, USA
| | - Laurie S Kaguni
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Francisco J Cao-García
- Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
| | - Grzegorz L Ciesielski
- Department of Chemistry, Auburn University at Montgomery, Montgomery, AL 36117, USA.,Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI 48823, USA
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Faraday 9, 28049 Madrid, Spain.,Nanobiotecnología (IMDEA-Nanociencia), Unidad Asociada al Centro Nacional de Biotecnología (CSIC), 28049 Madrid, Spain
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7
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Park J, Baruch-Torres N, Yin YW. Structural and Molecular Basis for Mitochondrial DNA Replication and Transcription in Health and Antiviral Drug Toxicity. Molecules 2023; 28:1796. [PMID: 36838782 PMCID: PMC9961925 DOI: 10.3390/molecules28041796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023] Open
Abstract
Human mitochondrial DNA (mtDNA) is a 16.9 kbp double-stranded, circular DNA, encoding subunits of the oxidative phosphorylation electron transfer chain and essential RNAs for mitochondrial protein translation. The minimal human mtDNA replisome is composed of the DNA helicase Twinkle, DNA polymerase γ, and mitochondrial single-stranded DNA-binding protein. While the mitochondrial RNA transcription is carried out by mitochondrial RNA polymerase, mitochondrial transcription factors TFAM and TFB2M, and a transcription elongation factor, TEFM, both RNA transcriptions, and DNA replication machineries are intertwined and control mtDNA copy numbers, cellular energy supplies, and cellular metabolism. In this review, we discuss the mechanisms governing these main pathways and the mtDNA diseases that arise from mutations in transcription and replication machineries from a structural point of view. We also address the adverse effect of antiviral drugs mediated by mitochondrial DNA and RNA polymerases as well as possible structural approaches to develop nucleoside reverse transcriptase inhibitor and ribonucleosides analogs with reduced toxicity.
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Affiliation(s)
- Joon Park
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Noe Baruch-Torres
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Y. Whitney Yin
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
- Department of Pharmacology and Toxicology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
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8
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Peng J, Hu X, Fan S, Zhou J, Ren S, Sun R, Chen Y, Shen X, Chen Y. Inhibition of Mitochondrial Biosynthesis Using a "Right-Side-Out" Membrane-Camouflaged Micelle to Facilitate the Therapeutic Effects of Shikonin on Triple-Negative Breast Cancer. Adv Healthc Mater 2022; 11:e2200742. [PMID: 35818932 DOI: 10.1002/adhm.202200742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/15/2022] [Indexed: 01/27/2023]
Abstract
The mitochondria represent a potential target for the treatment of triple-negative breast cancer (TNBC) and shikonin (SK) has shown remarkable therapeutic effects on TNBC. Herein, it is found that SK possesses potent inhibitory effects on mitochondrial biogenesis via targeting polymerase gamma (POLG). However, its application is restricted by its poor aqueous solubility and stability, and therefore, a biomimetic micelle to aid with tumor lesion accumulation and mitochondria-targeted delivery of SK is designed. A folic acid (FA) conjugated polyethylene glycol derivative (FA-PEG-FA) is inserted onto the external membranes of red blood cells (FP-RBCm) to prepare a "right-side-out" RBCm-camouflaged cationic micelle (ThTM/SK@FP-RBCm). Both FP-RBCm coating and a triphenylphosphine (TPP) moiety on the periphery of micelles contribute to tumor lesion distribution, receptor-mediated cellular uptake, and electrostatic attraction-dependent mitochondrial targeting, thereby maximizing inhibitory effects on mitochondrial biosynthesis in TNBC cells. Intravenous administration of ThTM/SK@FP-RBCm leads to profound inhibition of tumor growth and lung metastasis in a TNBC mouse model with no obvious toxicity. This work highlights the mitochondria-targeted delivery of SK using a "right-side-out" membrane-camouflaged micelle for the inhibition of mitochondrial biogenesis and enhanced therapeutic effects on TNBC.
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Affiliation(s)
- Jianqing Peng
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China.,Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Xiaoxia Hu
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China
| | - Shuangqin Fan
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China
| | - Jia Zhou
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China
| | - Shuang Ren
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China
| | - Runbin Sun
- The Key Laboratory of Optimal Utilization of Natural Medicine Resources, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China
| | - Yi Chen
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China
| | - Xiangchun Shen
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China.,Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Yan Chen
- The High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,Translational Medicine Research Center of Guizhou Medical University, Guizhou Medical University, University Town, Guian New District, Guizhou, 550025, China.,The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang, Guizhou, 550025, China.,Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China
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9
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Della Valle F, Reddy P, Yamamoto M, Liu P, Saera-Vila A, Bensaddek D, Zhang H, Prieto Martinez J, Abassi L, Celii M, Ocampo A, Nuñez Delicado E, Mangiavacchi A, Aiese Cigliano R, Rodriguez Esteban C, Horvath S, Izpisua Belmonte JC, Orlando V. LINE-1 RNA causes heterochromatin erosion and is a target for amelioration of senescent phenotypes in progeroid syndromes. Sci Transl Med 2022; 14:eabl6057. [PMID: 35947677 DOI: 10.1126/scitranslmed.abl6057] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Constitutive heterochromatin is responsible for genome repression of DNA enriched in repetitive sequences, telomeres, and centromeres. During physiological and pathological premature aging, heterochromatin homeostasis is profoundly compromised. Here, we showed that LINE-1 (Long Interspersed Nuclear Element-1; L1) RNA accumulation was an early event in both typical and atypical human progeroid syndromes. L1 RNA negatively regulated the enzymatic activity of the histone-lysine N-methyltransferase SUV39H1 (suppression of variegation 3-9 homolog 1), resulting in heterochromatin loss and onset of senescent phenotypes in vitro. Depletion of L1 RNA in dermal fibroblast cells from patients with different progeroid syndromes using specific antisense oligonucleotides (ASOs) restored heterochromatin histone 3 lysine 9 and histone 3 lysine 27 trimethylation marks, reversed DNA methylation age, and counteracted the expression of senescence-associated secretory phenotype genes such as p16, p21, activating transcription factor 3 (ATF3), matrix metallopeptidase 13 (MMP13), interleukin 1a (IL1a), BTG anti-proliferation factor 2 (BTG2), and growth arrest and DNA damage inducible beta (GADD45b). Moreover, systemic delivery of ASOs rescued the histophysiology of tissues and increased the life span of a Hutchinson-Gilford progeria syndrome mouse model. Transcriptional profiling of human and mouse samples after L1 RNA depletion demonstrated that pathways associated with nuclear chromatin organization, cell proliferation, and transcription regulation were enriched. Similarly, pathways associated with aging, inflammatory response, innate immune response, and DNA damage were down-regulated. Our results highlight the role of L1 RNA in heterochromatin homeostasis in progeroid syndromes and identify a possible therapeutic approach to treat premature aging and related syndromes.
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Affiliation(s)
- Francesco Della Valle
- King Abdullah University of Science and Technology (KAUST), Biological Environmental Sciences and Engineering Division BESE, KAUST Environmental Epigenetics Program, Thuwal, Saudi Arabia
| | - Pradeep Reddy
- Salk Institute for Biological Studies, La Jolla, CA, USA.,Altos Labs, San Diego, CA, USA
| | - Mako Yamamoto
- Salk Institute for Biological Studies, La Jolla, CA, USA.,Altos Labs, San Diego, CA, USA
| | - Peng Liu
- King Abdullah University of Science and Technology (KAUST), Biological Environmental Sciences and Engineering Division BESE, KAUST Environmental Epigenetics Program, Thuwal, Saudi Arabia
| | | | - Dalila Bensaddek
- King Abdullah University of Science and Technology (KAUST), Bioscience Core Lab
| | - Huoming Zhang
- King Abdullah University of Science and Technology (KAUST), Bioscience Core Lab
| | | | - Leila Abassi
- King Abdullah University of Science and Technology (KAUST), Biological Environmental Sciences and Engineering Division BESE, KAUST Environmental Epigenetics Program, Thuwal, Saudi Arabia
| | - Mirko Celii
- King Abdullah University of Science and Technology (KAUST), Biological Environmental Sciences and Engineering Division BESE, KAUST Environmental Epigenetics Program, Thuwal, Saudi Arabia
| | | | | | - Arianna Mangiavacchi
- King Abdullah University of Science and Technology (KAUST), Biological Environmental Sciences and Engineering Division BESE, KAUST Environmental Epigenetics Program, Thuwal, Saudi Arabia
| | | | | | | | | | - Valerio Orlando
- King Abdullah University of Science and Technology (KAUST), Biological Environmental Sciences and Engineering Division BESE, KAUST Environmental Epigenetics Program, Thuwal, Saudi Arabia
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10
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Amorim JA, Coppotelli G, Rolo AP, Palmeira CM, Ross JM, Sinclair DA. Mitochondrial and metabolic dysfunction in ageing and age-related diseases. Nat Rev Endocrinol 2022; 18:243-258. [PMID: 35145250 PMCID: PMC9059418 DOI: 10.1038/s41574-021-00626-7] [Citation(s) in RCA: 220] [Impact Index Per Article: 110.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/17/2021] [Indexed: 12/11/2022]
Abstract
Organismal ageing is accompanied by progressive loss of cellular function and systemic deterioration of multiple tissues, leading to impaired function and increased vulnerability to death. Mitochondria have become recognized not merely as being energy suppliers but also as having an essential role in the development of diseases associated with ageing, such as neurodegenerative and cardiovascular diseases. A growing body of evidence suggests that ageing and age-related diseases are tightly related to an energy supply and demand imbalance, which might be alleviated by a variety of interventions, including physical activity and calorie restriction, as well as naturally occurring molecules targeting conserved longevity pathways. Here, we review key historical advances and progress from the past few years in our understanding of the role of mitochondria in ageing and age-related metabolic diseases. We also highlight emerging scientific innovations using mitochondria-targeted therapeutic approaches.
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Affiliation(s)
- João A Amorim
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, USA
- Center for Neurosciences and Cell Biology of the University of Coimbra, Coimbra, Portugal
- IIIUC, Institute of Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Giuseppe Coppotelli
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, USA
- George and Anne Ryan Institute for Neuroscience, College of Pharmacy, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | - Anabela P Rolo
- Center for Neurosciences and Cell Biology of the University of Coimbra, Coimbra, Portugal
- Department of Life Sciences of the University of Coimbra, Coimbra, Portugal
| | - Carlos M Palmeira
- Center for Neurosciences and Cell Biology of the University of Coimbra, Coimbra, Portugal
- Department of Life Sciences of the University of Coimbra, Coimbra, Portugal
| | - Jaime M Ross
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, USA
- George and Anne Ryan Institute for Neuroscience, College of Pharmacy, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | - David A Sinclair
- Department of Genetics, Blavatnik Institute, Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, USA.
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11
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Park J, Baruch-Torres N, Iwai S, Herrmann GK, Brieba LG, Yin YW. Human Mitochondrial DNA Polymerase Metal Dependent UV Lesion Bypassing Ability. Front Mol Biosci 2022; 9:808036. [PMID: 35355510 PMCID: PMC8959595 DOI: 10.3389/fmolb.2022.808036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/11/2022] [Indexed: 12/11/2022] Open
Abstract
Human mitochondrial DNA contains more UV-induced lesions than the nuclear DNA due to lack of mechanism to remove bulky photoproducts. Human DNA polymerase gamma (Pol γ) is the sole DNA replicase in mitochondria, which contains a polymerase (pol) and an exonuclease (exo) active site. Previous studies showed that Pol γ only displays UV lesion bypassing when its exonuclease activity is obliterated. To investigate the reaction environment on Pol γ translesion activity, we tested Pol γ DNA activity in the presence of different metal ions. While Pol γ is unable to replicate through UV lesions on DNA templates in the presence of Mg2+, it exhibits robust translesion DNA synthesis (TLS) on cyclobutane pyrimidine dimer (CPD)-containing template when Mg2+ was mixed with or completely replaced by Mn2+. Under these conditions, the efficiency of Pol γ′s TLS opposite CPD is near to that on a non-damaged template and is 800-fold higher than that of exonuclease-deficient Pol γ. Interestingly, Pol γ exhibits higher exonuclease activity in the presence of Mn2+ than with Mg2+, suggesting Mn2+-stimulated Pol γ TLS is not via suppressing its exonuclease activity. We suggest that Mn2+ ion expands Pol γ′s pol active site relative to Mg2+ so that a UV lesion can be accommodated and blocks the communication between pol and exo active sites to execute translesion DNA synthesis.
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Affiliation(s)
- Joon Park
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States
| | - Noe Baruch-Torres
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Mexico
| | - Shigenori Iwai
- Division of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan
| | - Geoffrey K. Herrmann
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States
| | - Luis G. Brieba
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Mexico
- *Correspondence: Luis G. Brieba, ; Y. Whitney Yin,
| | - Y. Whitney Yin
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States
- *Correspondence: Luis G. Brieba, ; Y. Whitney Yin,
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12
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Ruiz FX, Hoang A, Dilmore CR, DeStefano JJ, Arnold E. Structural basis of HIV inhibition by L-nucleosides: opportunities for drug development and repurposing. Drug Discov Today 2022; 27:1832-1846. [PMID: 35218925 DOI: 10.1016/j.drudis.2022.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/15/2022] [Accepted: 02/18/2022] [Indexed: 12/12/2022]
Abstract
Infection with HIV can cripple the immune system and lead to AIDS. Hepatitis B virus (HBV) is a hepadnavirus that causes human liver diseases. Both pathogens are major public health problems affecting millions of people worldwide. The polymerases from both viruses are the most common drug target for viral inhibition, sharing common architecture at their active sites. The L-nucleoside drugs emtricitabine and lamivudine are widely used HIV reverse transcriptase (RT) and HBV polymerase (Pol) inhibitors. Nevertheless, structural details of their binding to RT(Pol)/nucleic acid remained unknown until recently. Here, we discuss the implications of these structures, alongside related complexes with L-dNTPs, for the development of novel L-nucleos(t)ide drugs, and prospects for repurposing them.
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Affiliation(s)
- Francesc X Ruiz
- Center for Advanced Biotechnology and Medicine, and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA.
| | - Anthony Hoang
- Center for Advanced Biotechnology and Medicine, and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher R Dilmore
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, MD 20742, USA
| | - Jeffrey J DeStefano
- Department of Cell Biology and Molecular Genetics, University of Maryland College Park, College Park, MD 20742, USA
| | - Eddy Arnold
- Center for Advanced Biotechnology and Medicine, and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA.
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13
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Yoo JH. Antivirals for Coexistence with COVID-19: Brief Review for General Physicians. J Korean Med Sci 2021; 36:e298. [PMID: 34725982 PMCID: PMC8560319 DOI: 10.3346/jkms.2021.36.e298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/20/2022] Open
Abstract
In order to end the coronavirus disease 2019 (COVID-19) pandemic that has lasted for nearly two years, it is most necessary to introduce antiviral drugs specific to COVID-19 along with the establishment of herd immunity by vaccination. Candidates currently being studied include nucleoside analogues that inhibit replication, protease inhibitors, and entry blockers. Not only the virus itself, but also the host protein that the virus uses in its pathogenesis is the target of treatment. Although the severe acute respiratory syndrome coronavirus 2 will not be completely eradicated, if the use of antiviral drugs is established, the COVID-19 pandemic will end through coexistence with the virus.
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Affiliation(s)
- Jin-Hong Yoo
- Division of Infectious Diseases, Department of Internal Medicine, Bucheon St. Mary's Hospital, Bucheon, Korea
- Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
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14
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Perry JK, Appleby TC, Bilello JP, Feng JY, Schmitz U, Campbell EA. An atomistic model of the coronavirus replication-transcription complex as a hexamer assembled around nsp15. J Biol Chem 2021; 297:101218. [PMID: 34562452 PMCID: PMC8494237 DOI: 10.1016/j.jbc.2021.101218] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/23/2022] Open
Abstract
The SARS-CoV-2 replication-transcription complex is an assembly of nonstructural viral proteins that collectively act to reproduce the viral genome and generate mRNA transcripts. While the structures of the individual proteins involved are known, how they assemble into a functioning superstructure is not. Applying molecular modeling tools, including protein-protein docking, to the available structures of nsp7-nsp16 and the nucleocapsid, we have constructed an atomistic model of how these proteins associate. Our principal finding is that the complex is hexameric, centered on nsp15. The nsp15 hexamer is capped on two faces by trimers of nsp14/nsp16/(nsp10)2, which then recruit six nsp12/nsp7/(nsp8)2 polymerase subunits to the complex. To this, six subunits of nsp13 are arranged around the superstructure, but not evenly distributed. Polymerase subunits that coordinate dimers of nsp13 are capable of binding the nucleocapsid, which positions the 5'-UTR TRS-L RNA over the polymerase active site, a state distinguishing transcription from replication. Analysis of the viral RNA path through the complex indicates the dsRNA that exits the polymerase passes over the nsp14 exonuclease and nsp15 endonuclease sites before being unwound by a convergence of zinc fingers from nsp10 and nsp14. The template strand is then directed away from the complex, while the nascent strand is directed to the sites responsible for mRNA capping. The model presents a cohesive picture of the multiple functions of the coronavirus replication-transcription complex and addresses fundamental questions related to proofreading, template switching, mRNA capping, and the role of the endonuclease.
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Affiliation(s)
| | | | | | - Joy Y Feng
- Gilead Sciences, Inc, Foster City, California, USA
| | - Uli Schmitz
- Gilead Sciences, Inc, Foster City, California, USA
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, New York, USA
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15
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Manickchund N, du Plessis C, John MAA, Manzini TC, Gosnell BI, Moosa MYS. A case series of emtricitabine-induced pure red cell aplasia. South Afr J HIV Med 2021; 22:1271. [PMID: 34522429 PMCID: PMC8424770 DOI: 10.4102/sajhivmed.v22i1.1271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 06/29/2021] [Indexed: 11/04/2022] Open
Abstract
Background Anaemia is common in patients with retroviral disease. New or worsening anaemia after initiation of antiretroviral (ARV) treatment has a broad differential diagnosis. Objectives We describe six patients who developed transfusion-dependent anaemia on first-line therapy (tenofovir, emtricitabine and efavirenz) and, by exclusion, implicated emtricitabine in the aetiology of the anaemia. Method We conducted a retrospective chart review of patients seen at the Infectious Diseases specialist clinic at King Edward VIII Hospital in KwaZulu-Natal between 2014 and 2016. We focused on patients with isolated, refractory and transfusion-dependent anaemia occurring after initiation of ARVs, in whom bone marrow biopsies were consistent with pure red cell aplasia (PRCA) without an identifiable secondary cause. Results All the patients were female, with a median (range) age and baseline CD4 cell count of 42.5 (23–61) years and 237 (83–329) cells/mm3, respectively. Before presenting with symptomatic anaemia, the duration on emtricitabine was 4.5 (2–8) months. At presentation, all patients had an HIV viral load of < 1000 copies/mL and a CD4 cell count of 314 (213–389) cells/mm3. The median time to recovery following the discontinuation of emtricitabine was 2 (1–4) months. After a median of 12 months, all patients were successfully rechallenged with emtricitabine and remained well for a follow-up period of 24 (7–36) months. Conclusion This study provides strong circumstantial evidence that emtricitabine plays an important role in the pathogenesis of reversible PRCA. The mechanisms through which emtricitabine induces PRCA remain unclear and require further study.
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Affiliation(s)
- Nithendra Manickchund
- Department of Infectious Diseases, Faculty of Internal Medicine, King Edward VIII Hospital, Durban, South Africa.,Department of Infectious Diseases, School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Camille du Plessis
- Department of Infectious Diseases, Faculty of Internal Medicine, King Edward VIII Hospital, Durban, South Africa.,Department of Infectious Diseases, School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Melanie-Anne A John
- Department of Infectious Diseases, School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Thandekile C Manzini
- Department of Infectious Diseases, Faculty of Internal Medicine, King Edward VIII Hospital, Durban, South Africa.,Department of Infectious Diseases, School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Bernadett I Gosnell
- Department of Infectious Diseases, Faculty of Internal Medicine, King Edward VIII Hospital, Durban, South Africa.,Department of Infectious Diseases, School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Mahomed-Yunus S Moosa
- Department of Infectious Diseases, Faculty of Internal Medicine, King Edward VIII Hospital, Durban, South Africa.,Department of Infectious Diseases, School of Medicine, University of KwaZulu-Natal, Durban, South Africa
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16
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Bhatia S, Narayanan N, Nagpal S, Nair DT. Antiviral therapeutics directed against RNA dependent RNA polymerases from positive-sense viruses. Mol Aspects Med 2021; 81:101005. [PMID: 34311994 DOI: 10.1016/j.mam.2021.101005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 01/18/2023]
Abstract
Viruses with positive-sense single stranded RNA (+ssRNA) genomes are responsible for different diseases and represent a global health problem. In addition to developing new vaccines that protect against severe illness on infection, it is imperative to identify new antiviral molecules to treat infected patients. The genome of these RNA viruses generally codes for an enzyme with RNA dependent RNA polymerase (RdRP) activity. This molecule is centrally involved in the duplication of the RNA genome. Inhibition of this enzyme by small molecules will prevent duplication of the RNA genome and thus reduce the viral titer. An overview of the different therapeutic strategies used to inhibit RdRPs from +ssRNA viruses is provided, along with an analysis of these enzymes to highlight new binding sites for inhibitors.
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Affiliation(s)
- Sonam Bhatia
- Regional Centre for Biotechnology, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
| | - Naveen Narayanan
- Regional Centre for Biotechnology, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India
| | - Shilpi Nagpal
- Regional Centre for Biotechnology, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India; National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bangalore, 560065, India
| | - Deepak T Nair
- Regional Centre for Biotechnology, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, India.
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17
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Sadraeian M, da Cruz EF, Boyle RW, Bahou C, Chudasama V, Janini LM, Diaz RS, Guimarães FEG. Photoinduced Photosensitizer-Antibody Conjugates Kill HIV Env-Expressing Cells, Also Inactivating HIV. ACS OMEGA 2021; 6:16524-16534. [PMID: 34235324 PMCID: PMC8246456 DOI: 10.1021/acsomega.1c01721] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/27/2021] [Indexed: 06/01/2023]
Abstract
HIV-infected cells persist for decades in patients administered with antiretroviral therapy (ART). Meanwhile, an alarming surge in drug-resistant HIV viruses has been occurring. Addressing these issues, we propose the application of photoimmunotherapy (PIT) against not only HIV Env-expressing cells but also HIV. Previously, we showed that a human anti-gp41 antibody (7B2) conjugated to cationic or anionic photosensitizers (PSs) could specifically target and kill the HIV Env-expressing cells. Here, our photolysis studies revealed that the binding of photoimmunoconjugates (PICs) on the membrane of HIV Env-expressing cells is sufficient to induce necrotic cell death due to physical damage to the membrane by singlet oxygen, which is independent of the type of PSs. This finding persuaded us to study the virus photoinactivation of PICs using two HIV-1 strains, X4 HIV-1 NL4-3 and JR-CSF virus. We observed that the PICs could destroy the viral strains, probably via physical damage on the HIV envelope. In conclusion, we report the application of PIT as a possible dual-tool for HIV immunotherapy and ART by killing HIV-expressing cells and cell-free HIV, respectively.
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Affiliation(s)
- Mohammad Sadraeian
- São Carlos Institute of
Physics, University of São Paulo, Caixa Postal 369, São Carlos, SP CEP 13560-970, Brazil
| | | | - Ross W. Boyle
- Department
of Chemistry, University of Hull, Cottingham Road, Hull HU6 7RX, U.K.
| | - Calise Bahou
- Department
of Chemistry, University College London, London WC1H 0AJ, U.K.
| | - Vijay Chudasama
- Department
of Chemistry, University College London, London WC1H 0AJ, U.K.
| | | | - Ricardo Sobhie Diaz
- Laboratório
de Retrovirologia, Universidade Federal
de São Paulo, São
Paulo, Brazil
| | - Francisco E. G. Guimarães
- São Carlos Institute of
Physics, University of São Paulo, Caixa Postal 369, São Carlos, SP CEP 13560-970, Brazil
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18
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Young MJ, Imperial RJ, Lakhi S, Court DA. A non-radioactive DNA synthesis assay demonstrates that elements of the Sigma 1278b Mip1 mitochondrial DNA polymerase domain and C-terminal extension facilitate robust enzyme activity. Yeast 2021; 38:262-275. [PMID: 33270277 DOI: 10.1002/yea.3541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 11/20/2020] [Accepted: 11/26/2020] [Indexed: 11/06/2022] Open
Abstract
The yeast DNA polymerase gamma, Mip1, is a useful tool to investigate the impact of orthologous human disease variants on mitochondrial DNA (mtDNA) replication. However, Mip1 is characterized by a C-terminal extension (CTE) that is not found on orthologous metazoan DNA polymerases, and the CTE is required for robust enzymatic activity. Two MIP1 alleles exist in standard yeast strains, encoding Mip1[S] or Mip1[Σ]. Mip1[S] is associated with reduced mtDNA stability and increased error rates in vivo. Although the Mip1[S] allele was initially identified in S288c, the Mip1[Σ] allele is widely present among available yeast genome sequences, suggesting that it is the wild-type (WT) allele. We developed a novel non-radioactive polymerase gamma assay to assess Mip1 functioning at its intracellular location, the mitochondrial membrane. Membrane fractions were isolated from yeast cells expressing full-length or CTE truncation variants of Mip1[S] or a chimeric Mip1[S] isoform harboring the Mip1[Σ]-specific T661 residue (cMip1 T661). Relative incorporation of digoxigenin (DIG)-11-deoxyuridine monophosphate (DIG-dUMP) by cMip1 T661 was higher than that by Mip1[S]. A cMip1 T661variant lacking 175 C-terminal residues maintained WT levels of DIG-dUMP incorporation, whereas the C-terminal variant lacking 205 residues displayed a significant decrease in incorporation. Newly synthesized DIG-labeled DNA decreased during later phases of reactions carried out at 37°C, suggesting temperature-sensitive destabilization of the polymerase domain and/or increased shuttling of the nascent DNA into the exonuclease domain. Comparative analysis of Mip1 enzyme functions using our novel assay has further demonstrated the importance of the CTE and T661 encoded by MIP1[Σ] in yeast mtDNA replication.
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Affiliation(s)
- Matthew J Young
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA
| | - Robin J Imperial
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Truman Medical Center, University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Suman Lakhi
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Deborah A Court
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
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19
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Hoitsma NM, Whitaker AM, Schaich MA, Smith MR, Fairlamb MS, Freudenthal BD. Structure and function relationships in mammalian DNA polymerases. Cell Mol Life Sci 2020; 77:35-59. [PMID: 31722068 PMCID: PMC7050493 DOI: 10.1007/s00018-019-03368-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/11/2019] [Accepted: 10/31/2019] [Indexed: 12/19/2022]
Abstract
DNA polymerases are vital for the synthesis of new DNA strands. Since the discovery of DNA polymerase I in Escherichia coli, a diverse library of mammalian DNA polymerases involved in DNA replication, DNA repair, antibody generation, and cell checkpoint signaling has emerged. While the unique functions of these DNA polymerases are differentiated by their association with accessory factors and/or the presence of distinctive catalytic domains, atomic resolution structures of DNA polymerases in complex with their DNA substrates have revealed mechanistic subtleties that contribute to their specialization. In this review, the structure and function of all 15 mammalian DNA polymerases from families B, Y, X, and A will be reviewed and discussed with special emphasis on the insights gleaned from recently published atomic resolution structures.
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Affiliation(s)
- Nicole M Hoitsma
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Amy M Whitaker
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Matthew A Schaich
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Mallory R Smith
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Max S Fairlamb
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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20
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Hung M, Tokarsky EJ, Lagpacan L, Zhang L, Suo Z, Lansdon EB. Elucidating molecular interactions of L-nucleotides with HIV-1 reverse transcriptase and mechanism of M184V-caused drug resistance. Commun Biol 2019; 2:469. [PMID: 31872074 PMCID: PMC6910994 DOI: 10.1038/s42003-019-0706-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/11/2019] [Indexed: 01/22/2023] Open
Abstract
Emtricitabine (FTC) and lamivudine (3TC), containing an oxathiolane ring with unnatural (-)-stereochemistry, are widely used nucleoside reverse transcriptase inhibitors (NRTIs) in anti-HIV therapy. Treatment with FTC or 3TC primarily selects for the HIV-1 RT M184V/I resistance mutations. Here we provide a comprehensive kinetic and structural basis for inhibiting HIV-1 RT by (-)-FTC-TP and (-)-3TC-TP and drug resistance by M184V. (-)-FTC-TP and (-)-3TC-TP have higher binding affinities (1/Kd) for wild-type RT but slower incorporation rates than dCTP. HIV-1 RT ternary crystal structures with (-)-FTC-TP and (-)-3TC-TP corroborate kinetic results demonstrating that their oxathiolane sulfur orients toward the DNA primer 3'-terminus and their triphosphate exists in two different binding conformations. M184V RT displays greater (>200-fold) Kd for the L-nucleotides and moderately higher (>9-fold) Kd for the D-isomers compared to dCTP. The M184V RT structure illustrates how the mutation repositions the oxathiolane of (-)-FTC-TP and shifts its triphosphate into a non-productive conformation.
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Affiliation(s)
- Magdeleine Hung
- Gilead Sciences, Inc., 333 Lakeside Dr., Foster City, CA 94404 USA
| | - E. John Tokarsky
- The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210 USA
| | - Leanna Lagpacan
- Gilead Sciences, Inc., 333 Lakeside Dr., Foster City, CA 94404 USA
| | - Lijun Zhang
- Gilead Sciences, Inc., 333 Lakeside Dr., Foster City, CA 94404 USA
| | - Zucai Suo
- The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210 USA
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306 USA
| | - Eric B. Lansdon
- Gilead Sciences, Inc., 333 Lakeside Dr., Foster City, CA 94404 USA
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21
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Mitochondrial Dysfunction in Aging and Cancer. J Clin Med 2019; 8:jcm8111983. [PMID: 31731601 PMCID: PMC6912717 DOI: 10.3390/jcm8111983] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/01/2019] [Accepted: 11/13/2019] [Indexed: 12/14/2022] Open
Abstract
Aging is a major risk factor for developing cancer, suggesting that these two events may represent two sides of the same coin. It is becoming clear that some mechanisms involved in the aging process are shared with tumorigenesis, through convergent or divergent pathways. Increasing evidence supports a role for mitochondrial dysfunction in promoting aging and in supporting tumorigenesis and cancer progression to a metastatic phenotype. Here, a summary of the current knowledge of three aspects of mitochondrial biology that link mitochondria to aging and cancer is presented. In particular, the focus is on mutations and changes in content of the mitochondrial genome, activation of mitochondria-to-nucleus signaling and the newly discovered mitochondria-telomere communication.
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22
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Bertoletti N, Chan AH, Schinazi RF, Yin YW, Anderson KS. Structural insights into the recognition of nucleoside reverse transcriptase inhibitors by HIV-1 reverse transcriptase: First crystal structures with reverse transcriptase and the active triphosphate forms of lamivudine and emtricitabine. Protein Sci 2019; 28:1664-1675. [PMID: 31301259 PMCID: PMC6699100 DOI: 10.1002/pro.3681] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/03/2019] [Accepted: 07/08/2019] [Indexed: 12/27/2022]
Abstract
The retrovirus HIV-1 has been a major health issue since its discovery in the early 80s. In 2017, over 37 million people were infected with HIV-1, of which 1.8 million were new infections that year. Currently, the most successful treatment regimen is the highly active antiretroviral therapy (HAART), which consists of a combination of three to four of the current 26 FDA-approved HIV-1 drugs. Half of these drugs target the reverse transcriptase (RT) enzyme that is essential for viral replication. One class of RT inhibitors is nucleoside reverse transcriptase inhibitors (NRTIs), a crucial component of the HAART. Once incorporated into DNA, NRTIs function as a chain terminator to stop viral DNA replication. Unfortunately, treatment with NRTIs is sometimes linked to toxicity caused by off-target side effects. NRTIs may also target the replicative human mitochondrial DNA polymerase (Pol γ), causing long-term severe drug toxicity. The goal of this work is to understand the discrimination mechanism of different NRTI analogues by RT. Crystal structures and kinetic experiments are essential for the rational design of new molecules that are able to bind selectively to RT and not Pol γ. Structural comparison of NRTI-binding modes with both RT and Pol γ enzymes highlights key amino acids that are responsible for the difference in affinity of these drugs to their targets. Therefore, the long-term goal of this research is to develop safer, next generation therapeutics that can overcome off-target toxicity.
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Affiliation(s)
- Nicole Bertoletti
- Department of PharmacologyYale University School of MedicineNew HavenConnecticut
| | - Albert H. Chan
- Department of PharmacologyYale University School of MedicineNew HavenConnecticut
| | - Raymond F. Schinazi
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Center for AIDS ResearchEmory University School of MedicineAtlantaGeorgia
| | - Y. Whitney Yin
- Department of Pharmacology and ToxicologyUniversity of Texas Medical BranchGalvestonTexas
- Sealy Center for Structural BiologyUniversity of Texas Medical BranchGalvestonTexas
| | - Karen S. Anderson
- Department of PharmacologyYale University School of MedicineNew HavenConnecticut
- Department of Molecular Biophysics and BiochemistryYale University School of MedicineNew HavenConnecticut
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23
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Sowers ML, Anderson APP, Wrabl JO, Yin YW. Networked Communication between Polymerase and Exonuclease Active Sites in Human Mitochondrial DNA Polymerase. J Am Chem Soc 2019; 141:10821-10829. [PMID: 31251605 PMCID: PMC7119269 DOI: 10.1021/jacs.9b04655] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High fidelity human mitochondrial DNA polymerase (Pol γ) contains two active sites, a DNA polymerization site (pol) and a 3'-5' exonuclease site (exo) for proofreading. Although separated by 35 Å, coordination between the pol and exo sites is crucial to high fidelity replication. The biophysical mechanisms for this coordination are not completely understood. To understand the communication between the two active sites, we used a statistical-mechanical model of the protein ensemble to calculate the energetic landscape and local stability. We compared a series of structures of Pol γ, complexed with primer/template DNA, and either a nucleotide substrate or a series of nucleotide analogues, which are differentially incorporated and excised by pol and exo activity. Despite the nucleotide or its analogues being bound in the pol, Pol γ residue stability varied across the protein, particularly in the exo domain. This suggests that substrate presence in the pol can be "sensed" in the exo domain. Consistent with this hypothesis, in silico mutations made in one active site mutually perturbed the energetics of the other. To identify specific regions of the polymerase that contributed to this communication, we constructed an allosteric network connectivity map that further demonstrates specific pol-exo cooperativity. Thus, a cooperative network underlies energetic connectivity. We propose that Pol γ and other dual-function polymerases exploit an energetic coupling network that facilitates domain-domain communication to enhance discrimination between correct and incorrect nucleotides.
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Affiliation(s)
- Mark L. Sowers
- MD-PhD Combined Degree Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Andrew P. P. Anderson
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Program of Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, Texas 71115, United States
| | - James O. Wrabl
- Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Y. Whitney Yin
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Program of Quantitative and Computational Biosciences, Baylor College of Medicine, Houston, Texas 71115, United States
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24
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Zhao L. Mitochondrial DNA degradation: A quality control measure for mitochondrial genome maintenance and stress response. Enzymes 2019; 45:311-341. [PMID: 31627882 DOI: 10.1016/bs.enz.2019.08.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mitochondria play a central role in bioenergetics, and fulfill a plethora of functions in cell signaling, programmed cell death, and biosynthesis of key protein cofactors. Mitochondria harbor their own genomic DNA, which encodes protein subunits of the electron transport chain and a full set of transfer and ribosomal RNAs. Mitochondrial DNA (mtDNA) is essential for cellular and organismal functions, and defects in mitochondrial genome maintenance have been implicated in common human diseases and mitochondrial disorders. mtDNA repair and degradation are known pathways to cope with mtDNA damage; however, molecular factors involved in this process have remained unclear. Such knowledge is fundamental to the understanding of mitochondrial genomic maintenance and pathology, because mtDNA degradation may contribute to the etiology of mtDNA depletion syndromes and to the activation of the innate immune response by fragmented mtDNA. This article reviews the current literature regarding the importance of mitochondrial DNA degradation in mtDNA maintenance and stress response, and the recent progress in uncovering molecular factors involved in mtDNA degradation. These factors include key components of the mtDNA replication machinery, such as DNA polymerase γ, helicase Twinkle, and exonuclease MGME1, as well as a major DNA-packaging protein, mitochondrial transcription factor A (TFAM).
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Affiliation(s)
- Linlin Zhao
- Department of Chemistry, University of California, Riverside, Riverside, CA, United States.
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25
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Abstract
The biological basis of human aging remains one of the greatest unanswered scientific questions. Increasing evidence, however, points to a role for alterations in mitochondrial function as a potential central regulator of the aging process. Here, we focus primarily on three aspects of mitochondrial biology that link this ancient organelle to how and why we age. In particular, we discuss the role of mitochondria in regulating the innate immune system, the mechanisms linking mitochondrial quality control to age-dependent pathology, and the possibility that mitochondrial-to-nuclear signaling might regulate the rate of aging.
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Affiliation(s)
- Ji Yong Jang
- Aging Institute, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Arnon Blum
- Baruch Padeh Medical Center, Bar-Ilan University, Ramat Gan, Israel
| | - Jie Liu
- Aging Institute, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Toren Finkel
- Aging Institute, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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26
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Prakasha Gowda AS, Spratt TE. Active Site Interactions Impact Phosphoryl Transfer during Replication of Damaged and Undamaged DNA by Escherichia coli DNA Polymerase I. Chem Res Toxicol 2017; 30:2033-2043. [PMID: 29053918 DOI: 10.1021/acs.chemrestox.7b00257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Replicative DNA polymerases are able to discriminate between very similar substrates with high accuracy. One mechanism by which E. coli DNA polymerase I checks for Watson-Crick geometry is through a hydrogen bonding fork between Arg668 and the incoming dNTP and the minor groove of the primer terminus. The importance of the Arg-fork was examined by disrupting it with either a guanine to 3-deazaguanine substitution at the primer terminus or the use of a carbocyclic deoxyribose analog of dUTP. Using thio-substituted dNTPs and differential quench techniques, we determined that when the Arg-fork was disrupted, the rate-limiting step changed from a conformational change to phosphodiester bond formation. This result indicates that Arg668 is involved in the phosphoryl transfer step. We examined the role of the Arg-fork in the replication of four DNA damaged templates, O6-methylguanine (O6-mG), 8-oxo-7,8-dihydroguanine (oxoG), O2-[4-(3-pyridyl)-4-oxobutyl]thymine (O2-POB-T), and N2-[(7S,8R,9S,10R)-7,8,9,10-tetrahydro-8,9,10-trihydroxybenzo[a]pyren-7-yl]-guanine (N2-BP-G). In general, the guanine to 3-deazaguanine substitution caused a decrease in kpol that was proportional to kpol over five orders of magnitude. The linear relationship indicates that the Arg668-fork helps catalyze phosphoryl transfer by the same mechanism with all the substrates. Exceptions to the linear relationship were the incorporations of dTTP opposite G, oxoG, and O6mG, which showed large decreases in kpol, similar to that exhibited by the Watson-Crick base pairs. It was proposed that the incorporation of dTTP opposite G, oxoG, and O6mG occurred via Watson-Crick-like structures.
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Affiliation(s)
- A S Prakasha Gowda
- Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine , Hershey, Pennsylvania 17033, United States
| | - Thomas E Spratt
- Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University College of Medicine , Hershey, Pennsylvania 17033, United States
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27
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Vyas R, Reed AJ, Raper AT, Zahurancik WJ, Wallenmeyer PC, Suo Z. Structural basis for the D-stereoselectivity of human DNA polymerase β. Nucleic Acids Res 2017; 45:6228-6237. [PMID: 28402499 PMCID: PMC5449621 DOI: 10.1093/nar/gkx252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/24/2017] [Accepted: 04/03/2017] [Indexed: 12/20/2022] Open
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) with L-stereochemistry have long been an effective treatment for viral infections because of the strong D-stereoselectivity exhibited by human DNA polymerases relative to viral reverse transcriptases. The D-stereoselectivity of DNA polymerases has only recently been explored structurally and all three DNA polymerases studied to date have demonstrated unique stereochemical selection mechanisms. Here, we have solved structures of human DNA polymerase β (hPolβ), in complex with single-nucleotide gapped DNA and L-nucleotides and performed pre-steady-state kinetic analysis to determine the D-stereoselectivity mechanism of hPolβ. Beyond a similar 180° rotation of the L-nucleotide ribose ring seen in other studies, the pre-catalytic ternary crystal structures of hPolβ, DNA and L-dCTP or the triphosphate forms of antiviral drugs lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP) provide little structural evidence to suggest that hPolβ follows the previously characterized mechanisms of D-stereoselectivity. Instead, hPolβ discriminates against L-stereochemistry through accumulation of several active site rearrangements that lead to a decreased nucleotide binding affinity and incorporation rate. The two NRTIs escape some of the active site selection through the base and sugar modifications but are selected against through the inability of hPolβ to complete thumb domain closure.
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Affiliation(s)
- Rajan Vyas
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew J. Reed
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Austin T. Raper
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Walter J. Zahurancik
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Petra C. Wallenmeyer
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Zucai Suo
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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28
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Liu K, Zang Y, Guo X, Wei F, Yin J, Pang L, Chen D. The Δ133p53 Isoform Reduces Wtp53-induced Stimulation of DNA Pol γ Activity in the Presence and Absence of D4T. Aging Dis 2017; 8:228-239. [PMID: 28400988 PMCID: PMC5362181 DOI: 10.14336/ad.2016.0910] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 09/10/2016] [Indexed: 01/02/2023] Open
Abstract
The mitochondrial toxicity of nucleoside reverse transcriptase inhibitors (NRTIs) is due to the inhibition of mitochondrial DNA (mtDNA) polymerase γ (pol γ). Previous studies have shown that wild type p53 (wtp53) can interact with pol γ and mtDNA to enhance mitochondrial DNA base excision repair (mtBER) activity and increase the accuracy of DNA synthesis. The N-terminal transactivation domain and central specific DNA-binding domain of p53 play critical roles in the stimulation of BER. In this study, we identified the possible roles of wtp53, Δ40p53 and Δ133p53 in regulating mtDNA pol γ activity in cells with d4T treatment. The results show that Δ40p53 and Δ133p53 can exist in mitochondrial fragments and form polymers with themselves or wtp53. Unlike wtP53, Δ133p53 alone cannot increase DNA pol γ activity. More importantly, we found that Δ133p53 played a negative role in p53 stimulation of DNA pol γ activity when studied in d4T-treated and d4T-untreated mitochondrial extracts. Gel shift data also indicate that Δ40p53 and Δ133p53 cannot interact with APE. Wtp53 and Δ40p53 can act antagonize the effect of d4T inhibition of DNA pol γ activity. However, when wtp53 interacted with Δ133p53, DNA pol γ activity was significantly decreased. Conclusion: Δ133p53 negatively regulates p53’s stimulation of pol γ in the presence and absence of d4T.
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Affiliation(s)
- Kai Liu
- 1Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing 100069, China
| | - Yunjin Zang
- 2The Affiliated Hospital of Qingdao University, Organ Transplantation Center, Qingdao, Shandong 266003, China
| | - Xianghua Guo
- 1Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing 100069, China
| | - Feili Wei
- 1Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing 100069, China
| | - Jiming Yin
- 1Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing 100069, China
| | - Lijun Pang
- 1Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing 100069, China
| | - Dexi Chen
- 1Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing 100069, China
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29
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Abstract
Telbivudine (LdT) is an antiviral agent currently used in the treatment of chronic hepatitis B virus, which was first approved by the US FDA in 2006. The safety of LdT is of great importance for patients that receive long-term treatment for this condition. It has been confirmed that patients treated with LdT have significantly elevated creatine kinase levels. However, the mechanism responsible for this adverse reaction is unclear. This review summarizes the current literature of the adverse reactions of LdT and the possible mechanisms that are involved in chronic hepatitis B infection. Thus, we aim to provide guidance on best practices in using LdT and to provide evidence of the possible mechanisms of LdT-associated adverse reactions.
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Affiliation(s)
- Jianfei Long
- Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai 200040, China
| | - Min Wang
- College of Pharmacy, Fudan University, Shanghai, China
| | - Bicui Chen
- Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai 200040, China
| | - Jiming Zhang
- Department of Infectious Diseases, HuaShan Hospital, Fudan University, No.12 Middle Wu Lu Mu Qi Road, Shanghai 200040, China
| | - Bin Wang
- Department of Pharmacy, HuaShan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai 200040, China
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30
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Abstract
Mitochondria were first postulated to contribute to aging more than 40 years ago. During the following decades, multiple lines of evidence in model organisms and humans showed that impaired mitochondrial function can contribute to age-associated disease phenotypes and aging. However, in contrast to the original theory favoring oxidative damage as a cause for mtDNA mutations, there are now strong data arguing that most mammalian mtDNA mutations originate as replication errors made by the mtDNA polymerase. Currently, a substantial amount of mitochondrial research is focused on finding ways to either remove or counteract the effects of mtDNA mutations with the hope of extending the human health- and lifespan. This review summarizes the current knowledge regarding the formation of mtDNA mutations and their impact on mitochondrial function. We also critically discuss proposed pathways interlinked with mammalian mtDNA mutations and suggest future research strategies to elucidate the role of mtDNA mutations in aging.
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Affiliation(s)
- Timo E S Kauppila
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, D-50931 Cologne, Germany
| | - Johanna H K Kauppila
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, D-50931 Cologne, Germany
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, D-50931 Cologne, Germany; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden.
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31
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Structured States of Disordered Proteins from Genomic Sequences. Cell 2016; 167:158-170.e12. [PMID: 27662088 DOI: 10.1016/j.cell.2016.09.010] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 07/08/2016] [Accepted: 09/06/2016] [Indexed: 12/22/2022]
Abstract
Protein flexibility ranges from simple hinge movements to functional disorder. Around half of all human proteins contain apparently disordered regions with little 3D or functional information, and many of these proteins are associated with disease. Building on the evolutionary couplings approach previously successful in predicting 3D states of ordered proteins and RNA, we developed a method to predict the potential for ordered states for all apparently disordered proteins with sufficiently rich evolutionary information. The approach is highly accurate (79%) for residue interactions as tested in more than 60 known disordered regions captured in a bound or specific condition. Assessing the potential for structure of more than 1,000 apparently disordered regions of human proteins reveals a continuum of structural order with at least 50% with clear propensity for three- or two-dimensional states. Co-evolutionary constraints reveal hitherto unseen structures of functional importance in apparently disordered proteins.
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32
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Abstract
Recent advances in the field of mitochondrial DNA (mtDNA) replication highlight the diversity of both the mechanisms utilized and the structural and functional organization of the proteins at mtDNA replication fork, despite the relative simplicity of the animal mtDNA genome. DNA polymerase γ, mtDNA helicase and mitochondrial single-stranded DNA-binding protein-the key replisome proteins, have evolved distinct structural features and biochemical properties. These appear to be correlated with mtDNA genomic features in different metazoan taxa and with their modes of DNA replication, although substantial integrative research is warranted to establish firmly these links. To date, several modes of mtDNA replication have been described for animals: rolling circle, theta, strand-displacement, and RITOLS/bootlace. Resolution of a continuing controversy relevant to mtDNA replication in mammals/vertebrates will have a direct impact on the mechanistic interpretation of mtDNA-related human diseases. Here we review these subjects, integrating earlier and recent data to provide a perspective on the major challenges for future research.
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Affiliation(s)
- G L Ciesielski
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland; Michigan State University, East Lansing, MI, United States
| | - M T Oliveira
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho", Jaboticabal, SP, Brazil
| | - L S Kaguni
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland; Michigan State University, East Lansing, MI, United States.
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33
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Lenz SAP, Wetmore SD. Evaluating the Substrate Selectivity of Alkyladenine DNA Glycosylase: The Synergistic Interplay of Active Site Flexibility and Water Reorganization. Biochemistry 2016; 55:798-808. [PMID: 26765542 DOI: 10.1021/acs.biochem.5b01179] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Human alkyladenine DNA glycosylase (AAG) functions as part of the base excision repair (BER) pathway by cleaving the N-glycosidic bond that connects nucleobases to the sugar-phosphate backbone in DNA. AAG targets a range of structurally diverse purine lesions using nonspecific DNA-protein π-π interactions. Nevertheless, the enzyme discriminates against the natural purines and is inhibited by pyrimidine lesions. This study uses molecular dynamics simulations and seven different neutral or charged substrates, inhibitors, or canonical purines to probe how the bound nucleotide affects the conformation of the AAG active site, and the role of active site residues in dictating substrate selectivity. The neutral substrates form a common DNA-protein hydrogen bond, which results in a consistent active site conformation that maximizes π-π interactions between the aromatic residues and the nucleobase required for catalysis. Nevertheless, subtle differences in DNA-enzyme contacts for different neutral substrates explain observed differential catalytic efficiencies. In contrast, the exocyclic amino groups of the natural purines clash with active site residues, which leads to catalytically incompetent DNA-enzyme complexes due to significant reorganization of active site water. Specifically, water resides between the A nucleobase and the active site aromatic amino acids required for catalysis, while a shift in the position of the general base (E125) repositions (potentially nucleophilic) water away from G. Despite sharing common amino groups, the methyl substituents in cationic purine lesions (3MeA and 7MeG) exhibit repulsion with active site residues, which repositions the damaged bases in the active site in a manner that promotes their excision. Overall, we provide a structural explanation for the diverse yet discriminatory substrate selectivity of AAG and rationalize key kinetic data available for the enzyme. Specifically, our results highlight the complex interplay of many different DNA-protein interactions used by AAG to facilitate BER, as well as the crucial role of the general base and water (nucleophile) positioning. The insights gained from our work will aid the understanding of the function of other enzymes that use flexible active sites to exhibit diverse substrate specificity.
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Affiliation(s)
- Stefan A P Lenz
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge, Alberta, Canada T1K 3M4
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge, Alberta, Canada T1K 3M4
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