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Alfonso P, Butković A, Fernández R, Riesgo A, Elena SF. Unveiling the hidden viromes across the animal tree of life: insights from a taxonomic classification pipeline applied to invertebrates of 31 metazoan phyla. mSystems 2024; 9:e0012424. [PMID: 38651902 PMCID: PMC11097642 DOI: 10.1128/msystems.00124-24] [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: 01/26/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
Invertebrates constitute the majority of animal species on Earth, including most disease-causing agents or vectors, with more diverse viromes when compared to vertebrates. Recent advancements in high-throughput sequencing have significantly expanded our understanding of invertebrate viruses, yet this knowledge remains biased toward a few well-studied animal lineages. In this study, we analyze invertebrate DNA and RNA viromes for 31 phyla using 417 publicly available RNA-Seq data sets from diverse environments in the marine-terrestrial and marine-freshwater gradients. This study aims to (i) estimate virome compositions at the family level for the first time across the animal tree of life, including the first exploration of the virome in several phyla, (ii) quantify the diversity of invertebrate viromes and characterize the structure of invertebrate-virus infection networks, and (iii) investigate host phylum and habitat influence on virome differences. Results showed that a set of few viral families of eukaryotes, comprising Retroviridae, Flaviviridae, and several families of giant DNA viruses, were ubiquitous and highly abundant. Nevertheless, some differences emerged between phyla, revealing for instance a less diverse virome in Ctenophora compared to the other animal phyla. Compositional analysis of the viromes showed that the host phylum explained over five times more variance in composition than its habitat. Moreover, significant similarities were observed between the viromes of some phylogenetically related phyla, which could highlight the influence of co-evolution in shaping invertebrate viromes.IMPORTANCEThis study significantly enhances our understanding of the global animal virome by characterizing the viromes of previously unexamined invertebrate lineages from a large number of animal phyla. It showcases the great diversity of viromes within each phylum and investigates the role of habitat shaping animal viral communities. Furthermore, our research identifies dominant virus families in invertebrates and distinguishes phyla with analogous viromes. This study sets the road toward a deeper understanding of the virome across the animal tree of life.
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Affiliation(s)
- Pau Alfonso
- Instituto de Biología Integrativa de Sistemas (CSIC-Universitat de València), Paterna, València, Spain
| | - Anamarija Butković
- Institut Pasteur, Université Paris Cité, CNRS UMR6047 Archaeal Virology Unit, Paris, France
| | - Rosa Fernández
- Instituto de Biología Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Ana Riesgo
- Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain
- Department of Life Sciences, Natural History Museum of London, London, United Kingdom
| | - Santiago F. Elena
- Instituto de Biología Integrativa de Sistemas (CSIC-Universitat de València), Paterna, València, Spain
- The Santa Fe Institute, Santa Fe, New Mexico, USA
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2
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Yang CH, Wu CH, Lo SY, Lua AC, Chan YR, Li HC. Hepatitis C Virus Down-Regulates the Expression of Ribonucleotide Reductases to Promote Its Replication. Pathogens 2023; 12:892. [PMID: 37513740 PMCID: PMC10383090 DOI: 10.3390/pathogens12070892] [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: 05/19/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
Ribonucleotide reductases (RRs or RNRs) catalyze the reduction of the OH group on the 2nd carbon of ribose, reducing four ribonucleotides (NTPs) to the corresponding deoxyribonucleotides (dNTPs) to promote DNA synthesis. Large DNA viruses, such as herpesviruses and poxviruses, could benefit their replication through increasing dNTPs via expression of viral RRs. Little is known regarding the relationship between cellular RRs and RNA viruses. Mammalian RRs contain two subunits of ribonucleotide reductase M1 polypeptide (RRM1) and two subunits of ribonucleotide reductase M2 polypeptide (RRM2). In this study, expression of cellular RRMs, including RRM1 and RRM2, is found to be down-regulated in hepatitis C virus (HCV)-infected Huh7.5 cells and Huh7 cells with HCV subgenomic RNAs (HCVr). As expected, the NTP/dNTP ratio is elevated in HCVr cells. Compared with that of the control Huh7 cells with sh-scramble, the NTP/dNTP ratio of the RRM-knockdown cells is elevated. Knockdown of RRM1 or RRM2 increases HCV replication in HCV replicon cells. Moreover, inhibitors to RRMs, including Didox, Trimidox and hydroxyurea, enhance HCV replication. Among various HCV viral proteins, the NS5A and/or NS3/4A proteins suppress the expression of RRMs. When these are taken together, the results suggest that HCV down-regulates the expression of RRMs in cultured cells to promote its replication.
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Affiliation(s)
- Chee-Hing Yang
- Department of Microbiology and Immunology, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Cheng-Hao Wu
- Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan
| | - Shih-Yen Lo
- Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan
- Department of Laboratory Medicine and Biotechnology, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Ahai-Chang Lua
- Department of Laboratory Medicine and Biotechnology, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Yu-Ru Chan
- Department of Laboratory Medicine and Biotechnology, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
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Huff SE, Winter JM, Dealwis CG. Inhibitors of the Cancer Target Ribonucleotide Reductase, Past and Present. Biomolecules 2022; 12:biom12060815. [PMID: 35740940 PMCID: PMC9221315 DOI: 10.3390/biom12060815] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 06/01/2022] [Accepted: 06/07/2022] [Indexed: 01/02/2023] Open
Abstract
Ribonucleotide reductase (RR) is an essential multi-subunit enzyme found in all living organisms; it catalyzes the rate-limiting step in dNTP synthesis, namely, the conversion of ribonucleoside diphosphates to deoxyribonucleoside diphosphates. As expression levels of human RR (hRR) are high during cell replication, hRR has long been considered an attractive drug target for a range of proliferative diseases, including cancer. While there are many excellent reviews regarding the structure, function, and clinical importance of hRR, recent years have seen an increase in novel approaches to inhibiting hRR that merit an updated discussion of the existing inhibitors and strategies to target this enzyme. In this review, we discuss the mechanisms and clinical applications of classic nucleoside analog inhibitors of hRRM1 (large catalytic subunit), including gemcitabine and clofarabine, as well as inhibitors of the hRRM2 (free radical housing small subunit), including triapine and hydroxyurea. Additionally, we discuss novel approaches to targeting RR and the discovery of new classes of hRR inhibitors.
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Affiliation(s)
- Sarah E. Huff
- Department of Pediatrics, University of California, San Diego, CA 92093, USA;
| | - Jordan M. Winter
- Department of Surgery, Division of Surgical Oncology, University Hospitals Cleveland Medical Center, Akron, OH 44106, USA;
| | - Chris G. Dealwis
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
- Correspondence:
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4
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Lyu C, Li WD, Peng JM, Cai XH. Identification of interaction domains in the pseudorabies virus ribonucleotide reductase large and small subunits. Vet Microbiol 2020; 246:108740. [PMID: 32605757 DOI: 10.1016/j.vetmic.2020.108740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 05/16/2020] [Accepted: 05/25/2020] [Indexed: 11/17/2022]
Abstract
Alphaherpesviral ribonucleotide reductase (RNR) is composed of large (pUL39, RR1) and small (pUL40, RR2) subunits. This enzyme can catalyze conversion of ribonucleotide to deoxynucleotide diphosphates that are further phosphorylated into deoxynucleotide triphosphate (dNTPs). The dNTPs are substrates for de novo viral DNA synthesis in infected host cells. The enzymatic activity of RNR depends on association between RR1 and RR2. However, the molecular basis underlying alphaherpesviral RNR complex formation is still largely unknown. In the current study, we investigated the pseudorabies virus (PRV) RNR interaction domains in pUL39 and pUL40. The interaction of pUL39 and pUL40 was identified by co-immunoprecipitation (co-IP) and colocalization analyses. Furthermore, the interaction amino acid (aa) domains in pUL39 and pUL40 were mapped using a series of truncated proteins. Consequently, the 90-210 aa in pUL39 was identified to be responsible for the interaction with pUL40. In turn, the 66-152, 218-258 and 280-303 aa in pUL40 could interact with pUL39, respectively. Deletion of 90-210 aa in pUL39 completely abrogated the interaction with pUL40. Deletion of 66-152, 218-258 and 280-303 aa in pUL40 remarkably weakened the interaction with pUL39, whereas a weak interaction could still be observed. Amino acid sequence alignments showed that the interaction domains identified in PRV pUL39/pUL40 were relatively non-conserved among the selected RNR subunits in alphaherpesviruses HSV1, HSV2, HHV3(VZV), BHV1, EHV1 and DEV. However, they were relatively conserved among PRV, HSV1 and HSV2. Collectively, our findings provided some molecular targets for inhibition of pUL39-pUL40 interaction to antagonize viral replication in PRV infected hosts.
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Affiliation(s)
- Chuang Lyu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China
| | - Wei-Dong Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China
| | - Jin-Mei Peng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China
| | - Xue-Hui Cai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China.
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5
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Ravichandran K, Olshansky L, Nocera DG, Stubbe J. Subunit Interaction Dynamics of Class Ia Ribonucleotide Reductases: In Search of a Robust Assay. Biochemistry 2020; 59:1442-1453. [PMID: 32186371 DOI: 10.1021/acs.biochem.0c00001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ribonucleotide reductases (RNRs) catalyze the conversion of nucleotides (NDP) to deoxynucleotides (dNDP), in part, by controlling the ratios and quantities of dNTPs available for DNA replication and repair. The active form of Escherichia coli class Ia RNR is an asymmetric α2β2 complex in which α2 contains the active site and β2 contains the stable diferric-tyrosyl radical cofactor responsible for initiating the reduction chemistry. Each dNDP is accompanied by disulfide bond formation. We now report that, under in vitro conditions, β2 can initiate turnover in α2 catalytically under both "one" turnover (no external reductant, though producing two dCDPs) and multiple turnover (with an external reductant) assay conditions. In the absence of reductant, rapid chemical quench analysis of a reaction of α2, substrate, and effector with variable amounts of β2 (1-, 10-, and 100-fold less than α2) yields 3 dCDP/α2 at all ratios of α2:β2 with a rate constant of 8-9 s-1, associated with a rate-limiting conformational change. Stopped-flow fluorescence spectroscopy with a fluorophore-labeled β reveals that the rate constants for subunit association (163 ± 7 μM-1 s-1) and dissociation (75 ± 10 s-1) are fast relative to turnover, consistent with catalytic β2. When assaying in the presence of an external reducing system, the turnover number is dictated by the ratio of α2:β2, their concentrations, and the concentration and nature of the reducing system; the rate-limiting step can change from the conformational gating to a step or steps involving disulfide rereduction, dissociation of the inhibited α4β4 state, or both. The issues encountered with E. coli RNR are likely of importance in all class I RNRs and are central to understanding the development of screening assays for inhibitors of these enzymes.
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Affiliation(s)
- Kanchana Ravichandran
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Lisa Olshansky
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.,Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Daniel G Nocera
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - JoAnne Stubbe
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.,Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Ashford P, Hernandez A, Greco TM, Buch A, Sodeik B, Cristea IM, Grünewald K, Shepherd A, Topf M. HVint: A Strategy for Identifying Novel Protein-Protein Interactions in Herpes Simplex Virus Type 1. Mol Cell Proteomics 2016; 15:2939-53. [PMID: 27384951 PMCID: PMC5013309 DOI: 10.1074/mcp.m116.058552] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Indexed: 11/12/2022] Open
Abstract
Human herpesviruses are widespread human pathogens with a remarkable impact on worldwide public health. Despite intense decades of research, the molecular details in many aspects of their function remain to be fully characterized. To unravel the details of how these viruses operate, a thorough understanding of the relationships between the involved components is key. Here, we present HVint, a novel protein-protein intraviral interaction resource for herpes simplex virus type 1 (HSV-1) integrating data from five external sources. To assess each interaction, we used a scoring scheme that takes into consideration aspects such as the type of detection method and the number of lines of evidence. The coverage of the initial interactome was further increased using evolutionary information, by importing interactions reported for other human herpesviruses. These latter interactions constitute, therefore, computational predictions for potential novel interactions in HSV-1. An independent experimental analysis was performed to confirm a subset of our predicted interactions. This subset covers proteins that contribute to nuclear egress and primary envelopment events, including VP26, pUL31, pUL40, and the recently characterized pUL32 and pUL21. Our findings support a coordinated crosstalk between VP26 and proteins such as pUL31, pUS9, and the CSVC complex, contributing to the development of a model describing the nuclear egress and primary envelopment pathways of newly synthesized HSV-1 capsids. The results are also consistent with recent findings on the involvement of pUL32 in capsid maturation and early tegumentation events. Further, they open the door to new hypotheses on virus-specific regulators of pUS9-dependent transport. To make this repository of interactions readily accessible for the scientific community, we also developed a user-friendly and interactive web interface. Our approach demonstrates the power of computational predictions to assist in the design of targeted experiments for the discovery of novel protein-protein interactions.
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Affiliation(s)
- Paul Ashford
- From the: ‡Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK
| | - Anna Hernandez
- From the: ‡Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK; §Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Todd Michael Greco
- ¶Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544
| | - Anna Buch
- ‖Institute of Virology, Hannover Medical School, OE 4310, Carl-Neuberg-Str. 1, D-30623, Hannover, Germany
| | - Beate Sodeik
- ‖Institute of Virology, Hannover Medical School, OE 4310, Carl-Neuberg-Str. 1, D-30623, Hannover, Germany
| | - Ileana Mihaela Cristea
- ¶Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544;
| | - Kay Grünewald
- §Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Adrian Shepherd
- From the: ‡Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK
| | - Maya Topf
- From the: ‡Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK;
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7
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Methyl-2-arylidene hydrazinecarbodithioates: synthesis and biological activity. ACTA ACUST UNITED AC 2013; 67:650-656. [PMID: 32214621 PMCID: PMC7088650 DOI: 10.2478/s11696-013-0346-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 11/29/2012] [Accepted: 12/13/2012] [Indexed: 11/20/2022]
Abstract
Methyl-2-arylidene hydrazine-carbodithioate has not been of particular interest to researchers even though its metal complexes are extensively reported on due to their biological activity. This study examined the cytostatic and antiviral activity of twelve methyl-2-arylidene hydrazinecarbodithioates reported by many researchers as intermediates for the synthesis of thiosemicarbazides and the preparation of their metal complexes. Compounds IIc, IIi, and IIl with tridentate ligand features were found to have the lowest IC50 value (6.5 μM, ≈ 1 μM, and 0.8 μM, respectively) against HL60 human promyelocytic leukemia cells. They were also most inhibitory to human embryonic lung (HEL) fibroblast proliferation (5.3 μM, 17 μM, and 2.6 μM). Compound IIc and IIl show antiviral activity against wild-type herpes simplex virus (HSV), varicella zoster virus (VZV), and acyclovirresistant HSV; however, these activities were observed at concentrations at which the compounds also markedly inhibit HL60 and HEL cell proliferation.
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8
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Brosnahan M, Erb H, Perkins G, Divers T, Borges A, Osterrieder N. Serum Iron Parameters and Acute Experimental EHV-1 Infection in Horses. J Vet Intern Med 2012; 26:1232-5. [DOI: 10.1111/j.1939-1676.2012.00963.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/09/2012] [Accepted: 05/16/2012] [Indexed: 11/29/2022] Open
Affiliation(s)
- M.M. Brosnahan
- Baker Institute for Animal Health; Cornell University; Ithaca; NY
| | - H.N. Erb
- Department of Population Medicine & Diagnostic Sciences
| | - G.A. Perkins
- Department of Clinical Sciences; College of Veterinary Medicine (Perkins); Cornell University; Ithaca; NY
| | - T.J. Divers
- Department of Population Medicine & Diagnostic Sciences
| | - A.S. Borges
- Department of Veterinary Clinical Science; School of Veterinary Medicine and Animal Science; Univ Estadual Paulista (UNESP); Botucatu; SP; Brazil
| | - N. Osterrieder
- Institut für Virologie; Freie Universität Berlin; Berlin; Germany
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9
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Tholander F, Sjöberg BM. Discovery of antimicrobial ribonucleotide reductase inhibitors by screening in microwell format. Proc Natl Acad Sci U S A 2012; 109:9798-803. [PMID: 22665797 PMCID: PMC3382500 DOI: 10.1073/pnas.1113051109] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ribonucleotide reductase (RNR) catalyzes reduction of the four different ribonucleotides to their corresponding deoxyribonucleotides and is the rate-limiting enzyme in DNA synthesis. RNR is a well-established target for the antiproliferative drugs Gemzar and Hydrea, for antisense therapy, and in combination chemotherapies. Surprisingly, few novel drugs that target RNR have emerged, partly because RNR activity assays are laboratory-intense and exclude high-throughput methodologies. Here, we present a previously undescribed PCR-based assay for RNR activity measurements in microplate format. We validated the approach by screening a diverse library of 1,364 compounds for inhibitors of class I RNR from the opportunistic pathogen Pseudomonas aeruginosa, and we identified 27 inhibitors with IC(50) values from ∼200 nM to 30 μM. Interestingly, a majority of the identified inhibitors have been found inactive in human cell lines as well as in anticancer and in vivo tumor tests as reported by the PubChem BioAssay database. Four of the RNR inhibitors inhibited growth of P. aeruginosa, and two were also found to affect the transcription of RNR genes and to decrease the cellular deoxyribonucleotide pools. This unique PCR-based assay works with any RNR enzyme and any substrate nucleotide, and thus opens the door to high-throughput screening for RNR inhibitors in drug discovery.
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Affiliation(s)
- Fredrik Tholander
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden; and
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm, Sweden; and
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Huang SW, Tzeng HF. Simultaneous determination of deoxycytidine diphosphate and deoxycytidine triphosphate by capillary electrophoresis with transient isotachophoretic stacking: a sensitive monitoring method for ribonucleotide reductase activity. Electrophoresis 2011; 33:536-42. [PMID: 22212996 DOI: 10.1002/elps.201100474] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 09/28/2011] [Accepted: 10/07/2011] [Indexed: 01/12/2023]
Abstract
A simple and rapid capillary electrophoretic method was developed for simultaneous determination of sub-micromolar 2'-deoxycytidine 5'-diphosphate (dCDP) and 2'-deoxycytidine 5'-triphosphate (dCTP) levels in enzyme assays without using radioactively labeled substrates. The separation was performed at 25°C using MES in the BGE as the terminating ion, the chloride ions in the sample buffer as the leading ion, and PEG 4000 in the BGE as the EOF suppressor for sample stacking by transient isotachophoresis (tITP). Several parameters affecting the separation were investigated, including the pH of the BGE, the concentration of sodium chloride in the sample buffer, and the concentrations of MES and PEG 4000 in the running buffer. Good separation with high separation efficiency was achieved within 6 min under optimal conditions. In comparison with the simple CZE method, the present tITP-CZE method enabled a 150-fold increase in the injection time without any decrease in resolution and the sensitivity was enhanced up to two orders of magnitude with the new method. The linear range of the method was 0.1-10 μM for dCDP and dCTP. The limits of detection of dCDP and dCTP were 85 and 73 nM, respectively. The proposed method was successfully applied for the activity assay of ribonucleotide reductase from Hep G2 and Sf9 cells.
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Affiliation(s)
- Shi-Wei Huang
- Department of Applied Chemistry, National Chi Nan University, Puli, Nantou County, Taiwan
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11
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Luo J, Gräslund A. Ribonucleotide reductase inhibition by p-alkoxyphenols studied by molecular docking and molecular dynamics simulations. Arch Biochem Biophys 2011; 516:29-34. [DOI: 10.1016/j.abb.2011.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 09/02/2011] [Accepted: 09/13/2011] [Indexed: 10/17/2022]
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12
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Targeting the Large Subunit of Human Ribonucleotide Reductase for Cancer Chemotherapy. Pharmaceuticals (Basel) 2011; 4:1328-1354. [PMID: 23115527 PMCID: PMC3483043 DOI: 10.3390/ph4101328] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Ribonucleotide reductase (RR) is a crucial enzyme in de novo DNA synthesis, where it catalyses the rate determining step of dNTP synthesis. RRs consist of a large subunit called RR1 (α), that contains two allosteric sites and one catalytic site, and a small subunit called RR2 (β), which houses a tyrosyl free radical essential for initiating catalysis. The active form of mammalian RR is an αnβm hetero oligomer. RR inhibitors are cytotoxic to proliferating cancer cells. In this brief review we will discuss the three classes of RR, the catalytic mechanism of RR, the regulation of the dNTP pool, the substrate selection, the allosteric activation, inactivation by ATP and dATP, and the nucleoside drugs that target RR. We will also discuss possible strategies for developing a new class of drugs that disrupts the RR assembly.
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13
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Tomter AB, Zoppellaro G, Schmitzberger F, Andersen NH, Barra AL, Engman H, Nordlund P, Andersson KK. HF-EPR, Raman, UV/VIS light spectroscopic, and DFT studies of the ribonucleotide reductase R2 tyrosyl radical from Epstein-Barr virus. PLoS One 2011; 6:e25022. [PMID: 21980375 PMCID: PMC3181257 DOI: 10.1371/journal.pone.0025022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 08/22/2011] [Indexed: 11/19/2022] Open
Abstract
Epstein-Barr virus (EBV) belongs to the gamma subfamily of herpes viruses, among the most common pathogenic viruses in humans worldwide. The viral ribonucleotide reductase small subunit (RNR R2) is involved in the biosynthesis of nucleotides, the DNA precursors necessary for viral replication, and is an important drug target for EBV. RNR R2 generates a stable tyrosyl radical required for enzymatic turnover. Here, the electronic and magnetic properties of the tyrosyl radical in EBV R2 have been determined by X-band and high-field/high-frequency electron paramagnetic resonance (EPR) spectroscopy recorded at cryogenic temperatures. The radical exhibits an unusually low g₁-tensor component at 2.0080, indicative of a positive charge in the vicinity of the radical. Consistent with these EPR results a relatively high C-O stretching frequency associated with the phenoxyl radical (at 1508 cm⁻¹) is observed with resonance Raman spectroscopy. In contrast to mouse R2, EBV R2 does not show a deuterium shift in the resonance Raman spectra. Thus, the presence of a water molecule as a hydrogen bond donor moiety could not be identified unequivocally. Theoretical simulations showed that a water molecule placed at a distance of 2.6 Å from the tyrosyl-oxygen does not result in a detectable deuterium shift in the calculated Raman spectra. UV/VIS light spectroscopic studies with metal chelators and tyrosyl radical scavengers are consistent with a more accessible dimetal binding/radical site and a lower affinity for Fe²⁺ in EBV R2 than in Escherichia coli R2. Comparison with previous studies of RNR R2s from mouse, bacteria, and herpes viruses, demonstrates that finely tuned electronic properties of the radical exist within the same RNR R2 Ia class.
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Affiliation(s)
- Ane B. Tomter
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | | | - Florian Schmitzberger
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Niels H. Andersen
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses, LNCMI-G, UPR 3228, CNRS, Grenoble, France
| | - Henrik Engman
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Pär Nordlund
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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Milho R, Gill MB, May JS, Colaco S, Stevenson PG. In vivo function of the murid herpesvirus-4 ribonucleotide reductase small subunit. J Gen Virol 2011; 92:1550-1560. [PMID: 21471322 PMCID: PMC3167896 DOI: 10.1099/vir.0.031542-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The difficulty of eliminating herpesvirus carriage makes host entry a key target for infection control. However, its viral requirements are poorly defined. Murid herpesvirus-4 (MuHV-4) can potentially provide insights into gammaherpesvirus host entry. Upper respiratory tract infection requires the MuHV-4 thymidine kinase (TK) and ribonucleotide reductase large subunit (RNR-L), suggesting a need for increased nucleotide production. However, both TK and RNR-L are likely to be multifunctional. We therefore tested further the importance of nucleotide production by disrupting the MuHV-4 ribonucleotide reductase small subunit (RNR-S). This caused a similar attenuation to RNR-L disruption: despite reduced intra-host spread, invasive inoculations still established infection, whereas a non-invasive upper respiratory tract inoculation did so only at high dose. Histological analysis showed that RNR-S−, RNR-L− and TK− viruses all infected cells in the olfactory neuroepithelium but unlike wild-type virus then failed to spread. Thus captured host nucleotide metabolism enzymes, up to now defined mainly as important for alphaherpesvirus reactivation in neurons, also have a key role in gammaherpesvirus host entry. This seemed to reflect a requirement for lytic replication to occur in a terminally differentiated cell before a viable pool of latent genomes could be established.
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Affiliation(s)
- Ricardo Milho
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Michael B Gill
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Janet S May
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Susanna Colaco
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Philip G Stevenson
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
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Function and regulation of class I ribonucleotide reductase-encoding genes in mycobacteria. J Bacteriol 2008; 191:985-95. [PMID: 19028890 DOI: 10.1128/jb.01409-08] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ribonucleotide reductases (RNRs) are crucial to all living cells, since they provide deoxyribonucleotides (dNTPs) for DNA synthesis and repair. In Mycobacterium tuberculosis, a class Ib RNR comprising nrdE- and nrdF2-encoded subunits is essential for growth in vitro. Interestingly, the genome of this obligate human pathogen also contains the nrdF1 (Rv1981c) and nrdB (Rv0233) genes, encoding an alternate class Ib RNR small (R2) subunit and a putative class Ic RNR R2 subunit, respectively. However, the role(s) of these subunits in dNTP provision during M. tuberculosis pathogenesis is unknown. In this study, we demonstrate that nrdF1 and nrdB are dispensable for the growth and survival of M. tuberculosis after exposure to various stresses in vitro and, further, that neither gene is required for growth and survival in mice. These observations argue against a specialist role for the alternate R2 subunits under the conditions tested. Through the construction of nrdR-deficient mutants of M. tuberculosis and Mycobacterium smegmatis, we establish that the genes encoding the essential class Ib RNR subunits are specifically regulated by an NrdR-type repressor. Moreover, a strain of M. smegmatis mc(2)155 lacking the 56-kb chromosomal region, which includes duplicates of nrdHIE and nrdF2, and a mutant retaining only one copy of nrdF2 are shown to be hypersensitive to the class I RNR inhibitor hydroxyurea as a result of depleted levels of the target. Together, our observations identify a potential vulnerability in dNTP provision in mycobacteria and thereby offer a compelling rationale for pursuing the class Ib RNR as a target for drug discovery.
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Nurbo J, Roos AK, Muthas D, Wahlström E, Ericsson DJ, Lundstedt T, Unge T, Karlén A. Design, synthesis and evaluation of peptide inhibitors ofMycobacterium tuberculosis ribonucleotide reductase. J Pept Sci 2007; 13:822-32. [DOI: 10.1002/psc.906] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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