1
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Francis JW, Hausmann S, Ikram S, Yin K, Mealey-Farr R, Flores NM, Trinh AT, Chasan T, Thompson J, Mazur PK, Gozani O. FAM86A methylation of eEF2 links mRNA translation elongation to tumorigenesis. Mol Cell 2024; 84:1753-1763.e7. [PMID: 38508183 PMCID: PMC11069438 DOI: 10.1016/j.molcel.2024.02.037] [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: 08/18/2023] [Revised: 01/16/2024] [Accepted: 02/29/2024] [Indexed: 03/22/2024]
Abstract
eEF2 post-translational modifications (PTMs) can profoundly affect mRNA translation dynamics. However, the physiologic function of eEF2K525 trimethylation (eEF2K525me3), a PTM catalyzed by the enzyme FAM86A, is unknown. Here, we find that FAM86A methylation of eEF2 regulates nascent elongation to promote protein synthesis and lung adenocarcinoma (LUAD) pathogenesis. The principal physiologic substrate of FAM86A is eEF2, with K525me3 modeled to facilitate productive eEF2-ribosome engagement during translocation. FAM86A depletion in LUAD cells causes 80S monosome accumulation and mRNA translation inhibition. FAM86A is overexpressed in LUAD and eEF2K525me3 levels increase through advancing LUAD disease stages. FAM86A knockdown attenuates LUAD cell proliferation and suppression of the FAM86A-eEF2K525me3 axis inhibits cancer cell and patient-derived LUAD xenograft growth in vivo. Finally, FAM86A ablation strongly attenuates tumor growth and extends survival in KRASG12C-driven LUAD mouse models. Thus, our work uncovers an eEF2 methylation-mediated mRNA translation elongation regulatory node and nominates FAM86A as an etiologic agent in LUAD.
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Affiliation(s)
| | - Simone Hausmann
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sabeen Ikram
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Kunlun Yin
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Natasha Mahealani Flores
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Annie Truc Trinh
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Tourkian Chasan
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Julia Thompson
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Pawel Karol Mazur
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Or Gozani
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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2
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Miyoshi T, Nomura T, Takeya K, Uchiumi T. The natural bicyclic hexapeptide RA-VII is a novel inhibitor of the eukaryotic translocase eEF2. Biochem Biophys Res Commun 2022; 615:88-93. [DOI: 10.1016/j.bbrc.2022.05.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/11/2022] [Indexed: 11/17/2022]
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3
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Shao Y, Molestak E, Su W, Stankevič M, Tchórzewski M. Sordarin - the antifungal antibiotic with a unique modus operandi. Br J Pharmacol 2021; 179:1125-1145. [PMID: 34767248 DOI: 10.1111/bph.15724] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/13/2021] [Accepted: 10/18/2021] [Indexed: 12/01/2022] Open
Abstract
Fungal infections cause serious problems in many aspects of human life, in particular infections in immunocompromised patients represent serious problems. Current antifungal antibiotics target various metabolic pathways, predominantly the cell wall or cellular membrane. Numerous compounds are available to combat fungal infections, but their efficacy is far from being satisfactory and some of them display high toxicity. The emerging resistance represents a serious issue as well; hence, there is a considerable need for new anti-fungal compounds with lower toxicity and higher effectiveness. One of the unique antifungal antibiotics is sordarin, the only known compound that acts on the fungal translational machinery per se. Sordarin inhibits protein synthesis at the elongation step of the translational cycle, acting on eukaryotic translation elongation factor 2. In this review, we intend to deliver a robust scientific platform promoting the development of antifungal compounds, in particular focusing on the molecular action of sordarin.
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Affiliation(s)
- Yutian Shao
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, PR China.,Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Eliza Molestak
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Weike Su
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, PR China.,National Engineering Research Center for Process Development of Active Pharmaceutical Ingredients, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou, PR China.,Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou, PR China
| | - Marek Stankevič
- Department of Organic Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie Sklodowska University, Lublin, Poland
| | - Marek Tchórzewski
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
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4
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Synthesis, antifungal activity and potential mechanism of fusidic acid derivatives possessing amino-terminal groups. Future Med Chem 2020; 12:763-774. [PMID: 32208979 DOI: 10.4155/fmc-2019-0289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Aim: Fusidic acid (FA) is a narrow-spectrum bacteriostatic antibiotic. We inadvertently discovered that a FA derivative modified by an amino-terminal group at the 3-OH position, namely 2, inhibited the growth of Cryptococcus neoformans. Methods & results: Multiscale molecular modeling approaches were used to analyze the binding modes of 2 with eEF2. FA derivatives modified at the 3-OH position were designed based on in silico models; seven derivatives possessing different amino-terminal groups were synthesized and tested in vitro for antifungal activity against C. neoformans. Conclusion: Compound 7 had the strongest minimum inhibitory concentration. Two protonated nitrogen atoms of 7 interacted with a negative electrostatic pocket of eEF2 likely explain the superiority of 7-2.
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5
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Liang XR, Ma XY, Ji NY. Trichosordarin A, a norditerpene glycoside from the marine-derived fungus Trichoderma harzianum R5. Nat Prod Res 2019; 34:2037-2042. [PMID: 30777455 DOI: 10.1080/14786419.2019.1574782] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A new sordarin derivative, trichosordarin A (1), with a unique norditerpene aglycone was isolated from the culture of a marine-sediment-derived fungal strain, Trichoderma harzianum R5. Its structure and relative configuration were unequivocally identified by a combination of 1D/2D NMR, IR, and mass spectrometric methods. Compound 1 was assayed to be toxic to the marine zooplankton Artemia salina.
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Affiliation(s)
- Xiao-Rui Liang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,Naval Aviation University, Yantai, China
| | - Xin-Yue Ma
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Nai-Yun Ji
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
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6
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Hawer H, Ütkür K, Arend M, Mayer K, Adrian L, Brinkmann U, Schaffrath R. Importance of diphthamide modified EF2 for translational accuracy and competitive cell growth in yeast. PLoS One 2018; 13:e0205870. [PMID: 30335802 PMCID: PMC6193676 DOI: 10.1371/journal.pone.0205870] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 01/23/2023] Open
Abstract
In eukaryotes, the modification of an invariant histidine (His-699 in yeast) residue in translation elongation factor 2 (EF2) with diphthamide involves a conserved pathway encoded by the DPH1-DPH7 gene network. Diphthamide is the target for diphtheria toxin and related lethal ADP ribosylases, which collectively kill cells by inactivating the essential translocase function of EF2 during mRNA translation and protein biosynthesis. Although this notion emphasizes the pathological importance of diphthamide, precisely why cells including our own require EF2 to carry it, is unclear. Mining the synthetic genetic array (SGA) landscape from the budding yeast Saccharomyces cerevisiae has revealed negative interactions between EF2 (EFT1-EFT2) and diphthamide (DPH1-DPH7) gene deletions. In line with these correlations, we confirm in here that loss of diphthamide modification (dphΔ) on EF2 combined with EF2 undersupply (eft2Δ) causes synthetic growth phenotypes in the composite mutant (dphΔ eft2Δ). These reflect negative interference with cell performance under standard as well as thermal and/or chemical stress conditions, cell growth rates and doubling times, competitive fitness, cell viability in the presence of TOR inhibitors (rapamycin, caffeine) and translation indicator drugs (hygromycin, anisomycin). Together with significantly suppressed tolerance towards EF2 inhibition by cytotoxic DPH5 overexpression and increased ribosomal -1 frame-shift errors in mutants lacking modifiable pools of EF2 (dphΔ, dphΔ eft2Δ), our data indicate that diphthamide is important for the fidelity of the EF2 translocation function during mRNA translation.
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Affiliation(s)
- Harmen Hawer
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Koray Ütkür
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Meike Arend
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Klaus Mayer
- Roche Pharma Research & Early Development, Large Molecule Research, Roche Innovation Center München, Penzberg, Germany
| | - Lorenz Adrian
- AG Geobiochemie, Department Isotopenbiogeochemie, Helmholtz-Zentrum für Umweltforschung GmbH–UFZ, Leipzig, Germany
- Fachgebiet Geobiotechnologie, Technische Universität Berlin, Berlin, Germany
| | - Ulrich Brinkmann
- Roche Pharma Research & Early Development, Large Molecule Research, Roche Innovation Center München, Penzberg, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
- * E-mail:
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7
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Pellegrino S, Demeshkina N, Mancera-Martinez E, Melnikov S, Simonetti A, Myasnikov A, Yusupov M, Yusupova G, Hashem Y. Structural Insights into the Role of Diphthamide on Elongation Factor 2 in mRNA Reading-Frame Maintenance. J Mol Biol 2018; 430:2677-2687. [PMID: 29886014 DOI: 10.1016/j.jmb.2018.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/11/2018] [Accepted: 06/04/2018] [Indexed: 01/27/2023]
Abstract
One of the most critical steps of protein biosynthesis is the coupled movement of mRNA, which encodes genetic information, with tRNAs on the ribosome. In eukaryotes, this process is catalyzed by a conserved G-protein, the elongation factor 2 (eEF2), which carries a unique post-translational modification, called diphthamide, found in all eukaryotic species. Here we present near-atomic resolution cryo-electron microscopy structures of yeast 80S ribosome complexes containing mRNA, tRNA and eEF2 trapped in different GTP-hydrolysis states which provide further structural insights into the role of diphthamide in the mechanism of translation fidelity in eukaryotes.
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Affiliation(s)
- Simone Pellegrino
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, CNRS UMR710, INSERM U964, University of Strasbourg, Strasbourg 67000, France
| | - Natalia Demeshkina
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, CNRS UMR710, INSERM U964, University of Strasbourg, Strasbourg 67000, France
| | - Eder Mancera-Martinez
- Architecture and Reactivity of RNA, University of Strasbourg, Institute of Molecular and Cellular Biology of the CNRS UPR9002, Strasbourg 67084, France
| | - Sergey Melnikov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, CNRS UMR710, INSERM U964, University of Strasbourg, Strasbourg 67000, France
| | - Angelita Simonetti
- Architecture and Reactivity of RNA, University of Strasbourg, Institute of Molecular and Cellular Biology of the CNRS UPR9002, Strasbourg 67084, France
| | - Alexander Myasnikov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, CNRS UMR710, INSERM U964, University of Strasbourg, Strasbourg 67000, France
| | - Marat Yusupov
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, CNRS UMR710, INSERM U964, University of Strasbourg, Strasbourg 67000, France; Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Russia.
| | - Gulnara Yusupova
- Department of Integrated Structural Biology, Institute of Genetics and Molecular and Cellular Biology, CNRS UMR710, INSERM U964, University of Strasbourg, Strasbourg 67000, France.
| | - Yaser Hashem
- ARNA, U1212 Université de Bordeaux, Institut Européen de Chimie et de Biologie (IECB) Inserm, Pessac 33600, France.
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8
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A mutated dph3 gene causes sensitivity of Schizosaccharomyces pombe cells to cytotoxic agents. Curr Genet 2017; 63:1081-1091. [PMID: 28555368 PMCID: PMC5668335 DOI: 10.1007/s00294-017-0711-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/11/2017] [Accepted: 05/23/2017] [Indexed: 12/11/2022]
Abstract
Dph3 is involved in diphthamide modification of the eukaryotic translation elongation factor eEF2 and in Elongator-mediated modifications of tRNAs, where a 5-methoxycarbonyl-methyl moiety is added to wobble uridines. Lack of such modifications affects protein synthesis due to inaccurate translation of mRNAs at ribosomes. We have discovered that integration of markers at the msh3 locus of Schizosaccharomyces pombe impaired the function of the nearby located dph3 gene. Such integrations rendered cells sensitive to the cytotoxic drugs hydroxyurea and methyl methanesulfonate. We constructed dph3 and msh3 strains with mutated ATG start codons (ATGmut), which allowed investigating drug sensitivity without potential interference by marker insertions. The dph3-ATGmut and a dph3::loxP-ura4-loxM gene disruption strain, but not msh3-ATGmut, turned out to be sensitive to hydroxyurea and methyl methanesulfonate, likewise the strains with cassettes integrated at the msh3 locus. The fungicide sordarin, which inhibits diphthamide modified eEF2 of Saccharomyces cerevisiae, barely affected survival of wild type and msh3Δ S. pombe cells, while the dph3Δ mutant was sensitive. The msh3-ATG mutation, but not dph3Δ or the dph3-ATG mutation caused a defect in mating-type switching, indicating that the ura4 marker at the dph3 locus did not interfere with Msh3 function. We conclude that Dph3 is required for cellular resistance to the fungicide sordarin and to the cytotoxic drugs hydroxyurea and methyl methanesulfonate. This is likely mediated by efficient translation of proteins in response to DNA damage and replication stress.
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9
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Abeyrathne PD, Koh CS, Grant T, Grigorieff N, Korostelev AA. Ensemble cryo-EM uncovers inchworm-like translocation of a viral IRES through the ribosome. eLife 2016; 5. [PMID: 27159452 PMCID: PMC4896748 DOI: 10.7554/elife.14874] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/08/2016] [Indexed: 12/17/2022] Open
Abstract
Internal ribosome entry sites (IRESs) mediate cap-independent translation of viral mRNAs. Using electron cryo-microscopy of a single specimen, we present five ribosome structures formed with the Taura syndrome virus IRES and translocase eEF2•GTP bound with sordarin. The structures suggest a trajectory of IRES translocation, required for translation initiation, and provide an unprecedented view of eEF2 dynamics. The IRES rearranges from extended to bent to extended conformations. This inchworm-like movement is coupled with ribosomal inter-subunit rotation and 40S head swivel. eEF2, attached to the 60S subunit, slides along the rotating 40S subunit to enter the A site. Its diphthamide-bearing tip at domain IV separates the tRNA-mRNA-like pseudoknot I (PKI) of the IRES from the decoding center. This unlocks 40S domains, facilitating head swivel and biasing IRES translocation via hitherto-elusive intermediates with PKI captured between the A and P sites. The structures suggest missing links in our understanding of tRNA translocation.
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Affiliation(s)
| | - Cha San Koh
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
| | - Timothy Grant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Nikolaus Grigorieff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Andrei A Korostelev
- RNA Therapeutics Institute, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, United States
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10
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Chakraborty B, Sejpal NV, Payghan PV, Ghoshal N, Sengupta J. Structure-based designing of sordarin derivative as potential fungicide with pan-fungal activity. J Mol Graph Model 2016; 66:133-42. [PMID: 27060894 DOI: 10.1016/j.jmgm.2016.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 03/23/2016] [Accepted: 03/24/2016] [Indexed: 11/25/2022]
Abstract
Fungal infections have become a significant problem for immunosuppressed patients. Sordarin, a promising fungicidal agent, inhibits fungal protein synthesis by impairing elongation factor-2 (eEF2) function. Intriguingly, despite high sequence similarity among eEF2s from different species, sordarin has been shown to inhibit translation specifically in certain fungi while unable to do so in some other fungal species (e.g. Candida parapsilosis and Candida lusitaniae). The sordarin binding site on eEF2 as well as its mechanism of action is known. In a previous study, we have detailed the interactions between sordarin and eEF2 cavities from different fungal species at the molecular level and predicted the probable cause of sordarin sensitivity. Guided by our previous analysis, we aimed for computer-aided designing of sordarin derivatives as potential fungicidal agents that still remain ineffective against human eEF2. We have performed structural knowledge-based designing of several sordarin derivatives and evaluated predicted interactions of those derivatives with the sordarin-binding cavities of different eEF2s, against which sordarin shows no inhibitory action. Our analyses identify an amino-pyrrole derivative as a good template for further designing of promising broad-spectrum antifungal agents. The drug likeness and ADMET prediction on this derivative also supports its suitability as a drug candidate.
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Affiliation(s)
- Biprashekhar Chakraborty
- Structural Biology & Bio-Informatics Division, Indian Institute of Chemical Biology (Council of Scientific & Industrial Research), 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Nikunjkumar Vinodray Sejpal
- The National Institute of Pharmaceutical Education and Research (NIPER), Indian Institute of Chemical Biology, Kolkata, India
| | - Pavan V Payghan
- Structural Biology & Bio-Informatics Division, Indian Institute of Chemical Biology (Council of Scientific & Industrial Research), 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Nanda Ghoshal
- Structural Biology & Bio-Informatics Division, Indian Institute of Chemical Biology (Council of Scientific & Industrial Research), 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Jayati Sengupta
- Structural Biology & Bio-Informatics Division, Indian Institute of Chemical Biology (Council of Scientific & Industrial Research), 4, Raja S.C. Mullick Road, Kolkata 700 032, India.
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11
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Schaffrath R, Abdel-Fattah W, Klassen R, Stark MJR. The diphthamide modification pathway from Saccharomyces cerevisiae--revisited. Mol Microbiol 2014; 94:1213-26. [PMID: 25352115 DOI: 10.1111/mmi.12845] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2014] [Indexed: 01/09/2023]
Abstract
Diphthamide is a conserved modification in archaeal and eukaryal translation elongation factor 2 (EF2). Its name refers to the target function for diphtheria toxin, the disease-causing agent that, through ADP ribosylation of diphthamide, causes irreversible inactivation of EF2 and cell death. Although this clearly emphasizes a pathobiological role for diphthamide, its physiological function is unclear, and precisely why cells need EF2 to contain diphthamide is hardly understood. Nonetheless, the conservation of diphthamide biosynthesis together with syndromes (i.e. ribosomal frame-shifting, embryonic lethality, neurodegeneration and cancer) typical of mutant cells that cannot make it strongly suggests that diphthamide-modified EF2 occupies an important and translation-related role in cell proliferation and development. Whether this is structural and/or regulatory remains to be seen. However, recent progress in dissecting the diphthamide gene network (DPH1-DPH7) from the budding yeast Saccharomyces cerevisiae has significantly advanced our understanding of the mechanisms required to initiate and complete diphthamide synthesis on EF2. Here, we review recent developments in the field that not only have provided novel, previously overlooked and unexpected insights into the pathway and the biochemical players required for diphthamide synthesis but also are likely to foster innovative studies into the potential regulation of diphthamide, and importantly, its ill-defined biological role.
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Affiliation(s)
- Raffael Schaffrath
- Department of Genetics, University of Leicester, Leicester, LE1 7RH, UK; Institut für Biologie, Abteilung Mikrobiologie, Universität Kassel, 34132, Kassel, Germany
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12
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Moriyama B, Gordon LA, McCarthy M, Henning SA, Walsh TJ, Penzak SR. Emerging drugs and vaccines for candidemia. Mycoses 2014; 57:718-33. [PMID: 25294098 DOI: 10.1111/myc.12265] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 08/26/2014] [Accepted: 09/01/2014] [Indexed: 11/27/2022]
Abstract
Candidemia and other forms of invasive candidiasis are important causes of morbidity and mortality. The evolving challenge of antimicrobial resistance among fungal pathogens continues to highlight the need for potent, new antifungal agents. MEDLINE, EMBASE, Scopus and Web of Science searches (up to January 2014) of the English-language literature were performed with the keywords 'Candida' or 'Candidemia' or 'Candidiasis' and terms describing investigational drugs with activity against Candida spp. Conference abstracts and the bibliographies of pertinent articles were also reviewed for relevant reports. ClinicalTrials.gov was searched for relevant clinical trials. Currently available antifungal agents for the treatment of candidemia are summarised. Investigational antifungal agents with potential activity against Candida bloodstream infections and other forms of invasive candidiasis and vaccines for prevention of Candida infections are also reviewed as are selected antifungal agents no longer in development. Antifungal agents currently in clinical trials include isavuconazole, albaconazole, SCY-078, VT-1161 and T-2307. Further data are needed to determine the role of these compounds in the treatment of candidemia and other forms of invasive candidiasis. The progressive reduction in antimicrobial drug development may result in a decline in antifungal drug discovery. Still, there remains a critical need for new antifungal agents to treat and prevent invasive candidiasis and other life-threatening mycoses.
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Affiliation(s)
- Brad Moriyama
- Pharmacy Department, NIH Clinical Center, Bethesda, MD, USA
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13
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Fung SY, Sofiyev V, Schneiderman J, Hirschfeld AF, Victor RE, Woods K, Piotrowski JS, Deshpande R, Li SC, de Voogd NJ, Myers CL, Boone C, Andersen RJ, Turvey SE. Unbiased screening of marine sponge extracts for anti-inflammatory agents combined with chemical genomics identifies girolline as an inhibitor of protein synthesis. ACS Chem Biol 2014; 9:247-57. [PMID: 24117378 DOI: 10.1021/cb400740c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Toll-like receptors (TLRs) play a critical role in innate immunity, but activation of TLR signaling pathways is also associated with many harmful inflammatory diseases. Identification of novel anti-inflammatory molecules targeting TLR signaling pathways is central to the development of new treatment approaches for acute and chronic inflammation. We performed high-throughput screening from crude marine sponge extracts on TLR5 signaling and identified girolline. We demonstrated that girolline inhibits signaling through both MyD88-dependent and -independent TLRs (i.e., TLR2, 3, 4, 5, and 7) and reduces cytokine (IL-6 and IL-8) production in human peripheral blood mononuclear cells and macrophages. Using a chemical genomics approach, we identified Elongation Factor 2 as the molecular target of girolline, which inhibits protein synthesis at the elongation step. Together these data identify the sponge natural product girolline as a potential anti-inflammatory agent acting through inhibition of protein synthesis.
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Affiliation(s)
- Shan-Yu Fung
- Department of Pediatrics, British Columbia Children’s Hospital and Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Vladimir Sofiyev
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Julia Schneiderman
- Department of Pediatrics, British Columbia Children’s Hospital and Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Aaron F. Hirschfeld
- Department of Pediatrics, British Columbia Children’s Hospital and Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Rachel E. Victor
- Department of Pediatrics, British Columbia Children’s Hospital and Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Kate Woods
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Jeff S. Piotrowski
- Great
Lakes Bioenergy Research Center, University of Wisconsin−Madison, Madison, Wisconsin 53726, United States
| | - Raamesh Deshpande
- Department
of Computer Science and Engineering, University of Minnesota−Twin Cities, Mineapolis, Minnesota 55455, United States
| | - Sheena C. Li
- Department
of Molecular Genetics, Terrence Donnelly Centre for Cellular and Biomolecular
Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Nicole J. de Voogd
- Netherlands
Centre for Biodiversity Naturalis, P.O.
Box 9517, 2300 RA, Leiden, The Netherlands
| | - Chad L. Myers
- Department
of Computer Science and Engineering, University of Minnesota−Twin Cities, Mineapolis, Minnesota 55455, United States
| | - Charlie Boone
- Department
of Molecular Genetics, Terrence Donnelly Centre for Cellular and Biomolecular
Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Raymond J. Andersen
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Stuart E. Turvey
- Department of Pediatrics, British Columbia Children’s Hospital and Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
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The amidation step of diphthamide biosynthesis in yeast requires DPH6, a gene identified through mining the DPH1-DPH5 interaction network. PLoS Genet 2013; 9:e1003334. [PMID: 23468660 PMCID: PMC3585130 DOI: 10.1371/journal.pgen.1003334] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Accepted: 01/07/2013] [Indexed: 01/31/2023] Open
Abstract
Diphthamide is a highly modified histidine residue in eukaryal translation elongation factor 2 (eEF2) that is the target for irreversible ADP ribosylation by diphtheria toxin (DT). In Saccharomyces cerevisiae, the initial steps of diphthamide biosynthesis are well characterized and require the DPH1-DPH5 genes. However, the last pathway step—amidation of the intermediate diphthine to diphthamide—is ill-defined. Here we mine the genetic interaction landscapes of DPH1-DPH5 to identify a candidate gene for the elusive amidase (YLR143w/DPH6) and confirm involvement of a second gene (YBR246w/DPH7) in the amidation step. Like dph1-dph5, dph6 and dph7 mutants maintain eEF2 forms that evade inhibition by DT and sordarin, a diphthamide-dependent antifungal. Moreover, mass spectrometry shows that dph6 and dph7 mutants specifically accumulate diphthine-modified eEF2, demonstrating failure to complete the final amidation step. Consistent with an expected requirement for ATP in diphthine amidation, Dph6 contains an essential adenine nucleotide hydrolase domain and binds to eEF2. Dph6 is therefore a candidate for the elusive amidase, while Dph7 apparently couples diphthine synthase (Dph5) to diphthine amidation. The latter conclusion is based on our observation that dph7 mutants show drastically upregulated interaction between Dph5 and eEF2, indicating that their association is kept in check by Dph7. Physiologically, completion of diphthamide synthesis is required for optimal translational accuracy and cell growth, as indicated by shared traits among the dph mutants including increased ribosomal −1 frameshifting and altered responses to translation inhibitors. Through identification of Dph6 and Dph7 as components required for the amidation step of the diphthamide pathway, our work paves the way for a detailed mechanistic understanding of diphthamide formation. Diphthamide is an unusual modified amino acid found uniquely in a single protein, eEF2, which is required for cells to synthesize new proteins. The name refers to its target function for eEF2 inactivation by diphtheria toxin, the disease-inducing agent produced by the pathogen Corynebacterium diphtheriae. Why cells require eEF2 to contain diphthamide is unclear, although mice unable to make it fail to complete embryogenesis. Cells generate diphthamide by modifying a specific histidine residue in eEF2 using a three-step biosynthetic pathway, the first two steps of which are well defined. However, the enzyme(s) involved in the final amidation step are unknown. Here we integrate genomic and molecular approaches to identify a candidate for the elusive amidase (Dph6) and confirm involvement of a second protein (Dph7) in the amidation step, showing that failure to synthesize diphthamide affects the accuracy of protein synthesis. In contrast to Dph6, however, Dph7 may be regulatory. Our data strongly suggest that it promotes dissociation of eEF2 from diphthine synthase (Dph5), which carries out the second step of diphthamide synthesis, and that Dph5 has a novel role as an eEF2 inhibitor when diphthamide synthesis is incomplete.
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15
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Chakraborty B, Mukherjee R, Sengupta J. Structural insights into the mechanism of translational inhibition by the fungicide sordarin. J Comput Aided Mol Des 2013; 27:173-84. [PMID: 23397219 DOI: 10.1007/s10822-013-9636-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/25/2013] [Indexed: 11/25/2022]
Abstract
The translational machinery has been found to be the target for a number of antibiotics. One such antibiotic sordarin selectively inhibits fungal translation by impairing the function of elongation factor 2 (eEF2) while being ineffective to higher eukaryotes. Surprisingly, sordarin is not even equally effective in impairing translation for all fungal species. The binding cavity of sordarin on eEF2 has been localized by X-ray crystallographic study and its unique specificity towards sordarin has been attributed to the species specific substitutions within a stretch of amino acids (sordarin specificity region, SSR) at the entrance of the cavity. In this study, we have analyzed the sordarin-binding cavity of eEF2 from different species both in isolated and ribosome-bound forms in order to decipher the mechanism of sordarin binding selectivity. Our results reveal that the molecular architecture as well as the microenvironment of the sordarin-binding cavity changes significantly from one species to another depending on the species specific substitutions within the cavity. Moreover, eEF2 binding to ribosome aggravates the effects of these substitutions. Thus, this study, while shedding light on the molecular mechanism underpinning the selective inhibitory effects of sordarin, will also be a helpful guide for future studies aiming at developing novel antifungal drugs with broader spectrum of activity.
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Affiliation(s)
- Biprashekhar Chakraborty
- Structural Biology and Bio-Informatics Division, Indian Institute of Chemical Biology (Council of Scientific and Industrial Research), 4, Raja S.C. Mullick Road, Kolkata 700 032, India
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Mochizuki M, Kitamyo M, Miyoshi T, Ito K, Uchiumi T. Analysis of chimeric ribosomal stalk complexes from eukaryotic and bacterial sources: structural features responsible for specificity of translation factors. Genes Cells 2012; 17:273-84. [DOI: 10.1111/j.1365-2443.2012.01586.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Hu ZY, Li YY, Lu CH, Lin T, Hu P, Shen YM. Seven Novel Linear Polyketides from Xylaria sp. NCY2. Helv Chim Acta 2010. [DOI: 10.1002/hlca.200900323] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Liang H. Sordarin, an antifungal agent with a unique mode of action. Beilstein J Org Chem 2008; 4:31. [PMID: 18941619 PMCID: PMC2568878 DOI: 10.3762/bjoc.4.31] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 08/26/2008] [Indexed: 11/23/2022] Open
Abstract
The sordarin family of compounds, characterized by a unique tetracyclic diterpene core including a norbornene system, inhibits protein synthesis in fungi by stabilizing the ribosome/EF2 complex. This mode of action is in contrast to typical antifungals, which target the cell membrane. This unusual bioactivity makes sordarin a promising candidate for the development of new fungicidal agents, and provided the motivation for extensive research. Three total syntheses (by the Kato, Mander and Narasaka groups), modifications of the glycosyl unit, and changes to the diterpene core (Cuevas and Ciufolini models) will also be discussed in this review.
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Affiliation(s)
- Huan Liang
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
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20
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Cotado-Sampayo M, Ramos PO, Perez RO, Ojha M, Barja F. Specificity of commercial anti-spectrin antibody in the study of fungal and Oomycete spectrin: cross-reaction with proteins other than spectrin. Fungal Genet Biol 2008; 45:1008-15. [PMID: 18378170 DOI: 10.1016/j.fgb.2008.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 02/12/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
Abstract
Spectrin was first described in erythrocytes where it forms a filamentous network in the cytoplasmic face of the plasma membrane and participates in the membrane's structural integrity in addition to controlling the lateral mobility of integral membrane proteins. In fungi, spectrin-like proteins have been described in the plasma membrane, concentrated mainly in the region of maximum apical expansion. This localization led to the idea of a spectrin based membrane skeleton in fungi participating in mechanical integrity of the plasma membrane, generating and maintaining cell polarity. The occurrence of spectrin-like proteins in filamentous fungi, yeasts and Oomycetes, however, is questionable since the presence of such proteins has only been demonstrated with immunochemical methods using antibodies whose specificity is unclear. There is no evidence of a gene coding for the high molecular weight alphabeta-spectrin in the genome of these organisms. Mass spectrometric analysis of the anti alphabeta-spectrin immunoreacting peptides from Neurospora crassa and Phytophthora infestans identified them as elongation factor 2 (NCU07700.4) and Hsp70 (PITG_13237.1), respectively. An attempt was made to correlate the reactivity of anti-spectrin antibody to a common feature of these three proteins i.e., spectrin, elongation factor 2 and heat shock protein 70, in that they all have a hydrophobic region implicated in chaperon activity.
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Affiliation(s)
- Marta Cotado-Sampayo
- Laboratory of Bioenergetics and Microbiology, University of Geneva, ch. des Embrouchis 10, CH 1254 Jussy-Geneva, Switzerland
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21
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Bommakanti AS, Lindahl L, Zengel JM. Mutation from guanine to adenine in 25S rRNA at the position equivalent to E. coli A2058 does not confer erythromycin sensitivity in Sacchromyces cerevisae. RNA (NEW YORK, N.Y.) 2008; 14:460-464. [PMID: 18218702 PMCID: PMC2248265 DOI: 10.1261/rna.786408] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Accepted: 11/27/2007] [Indexed: 05/25/2023]
Abstract
The macrolide erythromycin binds to the large subunit of the prokaryotic ribosome near the peptidyltransferase center (PTC) and inhibits elongation of new peptide chains beyond a few amino acids. Nucleotides A2058 and A2059 (E. coli numbering) in 23S rRNA play a crucial role in the binding of erythromycin, and mutation of nucleotide A2058 confers erythromycin resistance in both gram-positive and gram-negative bacteria. There are high levels of sequence and structural similarity in the PTC of prokaryotic and eukaryotic ribosomes. However, eukaryotic ribosomes are resistant to erythromycin and the presence of a G at the position equivalent to E. coli nucleotide A2058 is believed to be the reason. To test this hypothesis, we introduced a G to A mutation at this position of the yeast Saccharomyces cerevisiae 25S rRNA and analyzed sensitivity toward erythromycin. Neither growth studies nor erythromycin binding assays on mutated yeast ribosomes indicated any erythromycin sensitivity in mutated yeast strains. These results suggest that the identity of nucleotide 2058 is not the only determinant responsible for the difference in erythromycin sensitivity between yeast and prokaryotes.
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MESH Headings
- Base Sequence
- DNA Primers/genetics
- Drug Resistance, Fungal/genetics
- Erythromycin/metabolism
- Erythromycin/pharmacology
- Escherichia coli/drug effects
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Genes, Bacterial
- Genes, Fungal
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Nucleic Acid Conformation
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Fungal/chemistry
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- Ribosomes/metabolism
- Saccharomyces cerevisiae/drug effects
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Species Specificity
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Affiliation(s)
- Ananth S Bommakanti
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA
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22
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Demeshkina N, Hirokawa G, Kaji A, Kaji H. Novel activity of eukaryotic translocase, eEF2: dissociation of the 80S ribosome into subunits with ATP but not with GTP. Nucleic Acids Res 2007; 35:4597-607. [PMID: 17586816 PMCID: PMC1950535 DOI: 10.1093/nar/gkm468] [Citation(s) in RCA: 12] [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: 11/27/2022] Open
Abstract
Ribosomes must dissociate into subunits in order to begin protein biosynthesis. The enzymes that catalyze this fundamental process in eukaryotes remained unknown. Here, we demonstrate that eukaryotic translocase, eEF2, which catalyzes peptide elongation in the presence of GTP, dissociates yeast 80S ribosomes into subunits in the presence of ATP but not GTP or other nucleoside triphosphates. Dissociation was detected by light scattering or ultracentrifugation after the split subunits were stabilized. ATP was hydrolyzed during the eEF2-dependent dissociation, while a non-hydrolyzable analog of ATP was inactive in ribosome splitting by eEF2. GTP inhibited not only ATP hydrolysis but also dissociation. Sordarin, a fungal eEF2 inhibitor, averted the splitting but stimulated ATP hydrolysis. Another elongation inhibitor, cycloheximide, also prevented eEF2/ATP-dependent splitting, while the inhibitory effect of fusidic acid on the splitting was nominal. Upon dissociation of the 80S ribosome, eEF2 was found on the subunits. We propose that the dissociation activity of eEF2/ATP plays a role in mobilizing 80S ribosomes for protein synthesis during the shift up of physiological conditions.
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Affiliation(s)
- Natalia Demeshkina
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107 and Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Go Hirokawa
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107 and Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Akira Kaji
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107 and Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hideko Kaji
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107 and Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA
- *To whom correspondence should be addressed.+1 215 503 6547+1 215 923 7343
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23
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Brandi L, Fabbretti A, Milon P, Carotti M, Pon CL, Gualerzi CO. Methods for identifying compounds that specifically target translation. Methods Enzymol 2007; 431:229-67. [PMID: 17923238 DOI: 10.1016/s0076-6879(07)31012-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This chapter presents methods and protocols suitable for the identification and characterization of inhibitors of the prokaryotic and/or eukaryotic translational apparatus as a whole or targeting specific, underexploited targets of the bacterial protein synthetic machinery such as translation initiation and aminoacylation. Some of the methods described have been used successfully for the high-throughput screening of libraries of natural or synthetic compounds and make use of model "universal" mRNAs that can be translated with similar efficiency by cellfree extracts of bacterial, yeast, and HeLa cells. Other methods presented here are suitable for secondary screening tests aimed at identifying a specific target of an antibiotic within the translational pathway of prokaryotic cells.
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24
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Tully TP, Bergum JS, Schwarz SR, Durand SC, Howell JM, Patel RN, Cino PM. Improvement of sordarin production through process optimization: combining traditional approaches with DOE. J Ind Microbiol Biotechnol 2006; 34:193-202. [PMID: 17131104 DOI: 10.1007/s10295-006-0186-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 10/05/2006] [Indexed: 11/29/2022]
Abstract
BMS-353645, also known as sordarin, was of interest based on its activity against pathogenic fungi. The objective of these studies was to provide high quality starting substrate for chemical modification aimed at further improving biological activity, with particular interest in the inhibition of Aspergillus. In the work presented here, Design of Experiments, or DOE, was successfully combined with traditional approaches to significantly improve sordarin yields in fermentation flasks. Overall, yields were increased 25-fold from <100 microg/g to as high as 2,609 microg/g in flasks through the use of various medium and conduction changes supplemented with DOE. The improved process was then successfully scaled to pilot plant tanks with the best batch producing 2,389 microg/g sordarin at the 250-l scale.
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Affiliation(s)
- Thomas P Tully
- Enzyme Technology, Process Research and Development, Bristol-Myers Squibb Pharmaceutical Research Institute, P. O. Box 191, New Brunswick, NJ 08903, USA.
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25
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Søe R, Mosley RT, Justice M, Nielsen-Kahn J, Shastry M, Merrill AR, Andersen GR. Sordarin derivatives induce a novel conformation of the yeast ribosome translocation factor eEF2. J Biol Chem 2006; 282:657-66. [PMID: 17082187 DOI: 10.1074/jbc.m607830200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The sordarins are fungal specific inhibitors of the translation factor eEF2, which catalyzes the translocation of tRNA and mRNA after peptide bond formation. We have determined the crystal structures of eEF2 in complex with two novel sordarin derivatives. In both structures, the three domains of eEF2 that form the ligand-binding pocket are oriented in a different manner relative to the rest of eEF2 compared with our previous structure of eEF2 in complex with the parent natural product sordarin. Yeast eEF2 is also shown to bind adenylic nucleotides, which can be displaced by sordarin, suggesting that ADP or ATP also bind to the three C-terminal domains of eEF2. Fusidic acid is a universal inhibitor of translation that targets EF-G or eEF2 and is widely used as an antibiotic against Gram-positive bacteria. Based on mutations conferring resistance to fusidic acid, cryo-EM reconstructions, and x-ray structures of eEF2, EF-G, and an EF-G homolog, we suggest that the conformation of EF-G stalled on the 70 S ribosome by fusidic acid is similar to that of eEF2 trapped on the 80 S ribosome by sordarin.
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Affiliation(s)
- Rikke Søe
- Centre for Structural Biology, Department of Molecular Biology, University of Aarhus, DK-8000 Aarhus C, Denmark
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26
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27
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Wills EA, Redinbo MR, Perfect JR, Poeta MD. New potential targets for antifungal development. ACTA ACUST UNITED AC 2005. [DOI: 10.1517/14728222.4.3.265] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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28
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Arikan S, Rex JH. New agents for the treatment of systemic fungal infections – current status. Expert Opin Emerg Drugs 2005; 7:3-32. [PMID: 15989533 DOI: 10.1517/14728214.7.1.3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Systemic antifungal chemotherapy is enjoying its most dynamic era. More antifungal agents are under development than ever before, including agents in entirely new classes. Major goals of current investigations are to identify compounds with a wide spectrum of activity, minimal toxicity and a high degree of target specificity. The antifungal drugs in development include new azoles {voriconazole, posaconazole (formerly SCH-56592), ravuconazole (formerly BMS-207147)}, lipid formulations of amphotericin B, a lipid formulation of nystatin, echinocandins {anidulafungin (formerly, LY-303366, VER-002), caspofungin (formerly MK-991), micafungin (formerly FK-463)}, antifungal peptides other than echinocandins, and sordarin derivatives. This discussion reviews the currently available antifungal agents and summarises the developmental issues that surround these new systemic antifungal drugs.
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Affiliation(s)
- Sevtap Arikan
- Department of Microbiology and Clinical Microbiology, Hacettepe University Medical School, 06100 Ankara, Turkey.
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29
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Santos C, Rodríguez-Gabriel MA, Remacha M, Ballesta JPG. Ribosomal P0 protein domain involved in selectivity of antifungal sordarin derivatives. Antimicrob Agents Chemother 2004; 48:2930-6. [PMID: 15273103 PMCID: PMC478497 DOI: 10.1128/aac.48.8.2930-2936.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ribosomal stalk protein P0 is involved in the susceptibility to the antifungal sordarin derivatives, as reported for a number of Saccharomyces cerevisiae resistant mutants. Mammals and some lower eukaryotes are naturally resistant to these compounds. It is shown here that expression in S. cerevisiae of the ribosomal protein P0 from Homo sapiens and from other sordarin-resistant organisms results in a decrease in the sensitivity of the cells to an agent of this class. To further characterize the P0 region responsible for inducing sordarin resistance, a series of protein chimeras containing complementary regions of the human and yeast P0 proteins were constructed and expressed in yeast. The chimeras complement the absence of the native yeast P0 except in chimeras containing the human P0 carboxyl-terminal domain. Resistance to sordarins was found to be associated with the presence of an HsP0 amino acid sequence comprising P118 to F138, which unexpectedly led to higher resistance than the presence of the complete human P0. A comparison of the corresponding region in P0 from yeast and sordarin-insensitive organisms, followed by site-directed mutagenesis, indicates that residues in positions 119, 124, and 126 have an important role in determining resistance to sordarins. Moreover, since sordarins block the eukaryotic elongation factor 2 (EF2) function, the P0 region affecting sordarin susceptibility must correspond to EF2-interacting domains of the ribosomal stalk protein, which affects the drug-binding site in the elongation factor.
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Affiliation(s)
- C Santos
- Centro de Biología Molecular Severo Ochoa, CSIC and UAM, Canto Blanco, Madrid 28049, Spain
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30
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Domain movements of elongation factor eEF2 and the eukaryotic 80S ribosome facilitate tRNA translocation. EMBO J 2004; 23:1008-19. [PMID: 14976550 DOI: 10.1038/sj.emboj.7600102] [Citation(s) in RCA: 311] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Accepted: 01/08/2004] [Indexed: 11/09/2022] Open
Abstract
An 11.7-A-resolution cryo-EM map of the yeast 80S.eEF2 complex in the presence of the antibiotic sordarin was interpreted in molecular terms, revealing large conformational changes within eEF2 and the 80S ribosome, including a rearrangement of the functionally important ribosomal intersubunit bridges. Sordarin positions domain III of eEF2 so that it can interact with the sarcin-ricin loop of 25S rRNA and protein rpS23 (S12p). This particular conformation explains the inhibitory action of sordarin and suggests that eEF2 is stalled on the 80S ribosome in a conformation that has similarities with the GTPase activation state. A ratchet-like subunit rearrangement (RSR) occurs in the 80S.eEF2.sordarin complex that, in contrast to Escherichia coli 70S ribosomes, is also present in vacant 80S ribosomes. A model is suggested, according to which the RSR is part of a mechanism for moving the tRNAs during the translocation reaction.
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31
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Jørgensen R, Ortiz PA, Carr-Schmid A, Nissen P, Kinzy TG, Andersen GR. Two crystal structures demonstrate large conformational changes in the eukaryotic ribosomal translocase. Nat Struct Mol Biol 2003; 10:379-85. [PMID: 12692531 DOI: 10.1038/nsb923] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2002] [Accepted: 03/25/2003] [Indexed: 11/09/2022]
Abstract
Two crystal structures of yeast translation elongation factor 2 (eEF2) were determined: the apo form at 2.9 A resolution and eEF2 in the presence of the translocation inhibitor sordarin at 2.1 A resolution. The overall conformation of apo eEF2 is similar to that of its prokaryotic homolog elongation factor G (EF-G) in complex with GDP. Upon sordarin binding, the three tRNA-mimicking C-terminal domains undergo substantial conformational changes, while the three N-terminal domains containing the nucleotide-binding site form an almost rigid unit. The conformation of eEF2 in complex with sordarin is entirely different from known conformations observed in crystal structures of EF-G or from cryo-EM studies of EF-G-70S complexes. The domain rearrangements induced by sordarin binding and the highly ordered drug-binding site observed in the eEF2-sordarin structure provide a high-resolution structural basis for the mechanism of sordarin inhibition. The two structures also emphasize the dynamic nature of the ribosomal translocase.
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Affiliation(s)
- Rene Jørgensen
- Department of Molecular Biology, Aarhus University, Gustav Wieds vej 10C, DK8000 Arhus, Denmark
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32
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Polak A. Antifungal therapy--state of the art at the beginning of the 21st century. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2003; Spec No:59-190. [PMID: 12675476 DOI: 10.1007/978-3-0348-7974-3_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The most relevant information on the present state of the art of antifungal chemotherapy is reviewed in this chapter. For dermatomycoses a variety of topical antifungals are available, and safe and efficacious systemic treatment, especially with the fungicidal drug terbinafine, is possible. The duration of treatment can be drastically reduced. Substantial progress in the armamentarium of drugs for invasive fungal infections has been made, and a new class of antifungals, echinocandins, is now in clinical use. The following drugs in oral and/or intravenous formulations are available: the broad spectrum polyene amphotericin B with its new "clothes"; the sterol biosynthesis inhibitors fluconazole, itraconazole, and voriconazole; the glucan synthase inhibitor caspofungin; and the combination partner flucytosine. New therapy schedules have been studied; combination therapy has found a significant place in the treatment of severely compromised patients, and the field of prevention and empiric therapy is fast moving. Guidelines exist nowadays for the treatment of various fungal diseases and maintenance therapy. New approaches interfering with host defenses or pathogenicity of fungal cells are being investigated, and molecular biologists are looking for new targets studying the genomics of pathogenic fungi.
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Serrano-Wu MH, Laurent DRS, Carroll TM, Dodier M, Gao Q, Gill P, Quesnelle C, Marinier A, Mazzucco CE, Regueiro-Ren A, Stickle TM, Wu D, Yang H, Yang Z, Zheng M, Zoeckler ME, Vyas DM, Balasubramanian BN. Identification of a broad-spectrum azasordarin with improved pharmacokinetic properties. Bioorg Med Chem Lett 2003; 13:1419-23. [PMID: 12668003 DOI: 10.1016/s0960-894x(03)00161-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The synthesis and antifungal activity of 5'- and 5'-6'-substituted azasordarin derivatives are described. Modification of the 5'-position led to the discovery of the spirocyclopentyl analogue 7g, which is the first azasordarin to register single-digit MIC values versus Aspergillus spp. Further investigation identified the 5'-i-Pr derivative 7b, which displays superior pharmacokinetic properties compared to other azasordarins.
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Affiliation(s)
- Michael H Serrano-Wu
- Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06492, USA.
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34
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Quesnelle CA, Gill P, Dodier M, St Laurent D, Serrano-Wu M, Marinier A, Martel A, Mazzucco CE, Stickle TM, Barrett JF, Vyas DM, Balasubramanian BN. Sordaricin antifungal agents. Bioorg Med Chem Lett 2003; 13:519-24. [PMID: 12565963 DOI: 10.1016/s0960-894x(02)00937-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Compounds based on sordaricin were prepared via organometallic addition onto a fully protected sordaricin aldehyde. The fungal growth inhibition profiles for these compounds were established and the results are presented here. The synthesis of homologated sordaricin as well as ether and ester derivatives is presented, and structural rearrangement products upon oxidation. These compounds were evaluated as agents to inhibit fungal growth.
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Affiliation(s)
- Claude A Quesnelle
- Bristol-Myers Squibb Pharmaceutical Research Institute, 100, boul. de l'Industrie, Candiac, Québec, Canada J5R 1J1.
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35
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Regueiro-Ren A, Carroll TM, Chen Y, Matson JA, Huang S, Mazzucco CE, Stickle TM, Vyas DM, Balasubramanian BN. Core-modified sordaricin derivatives: synthesis and antifungal activity. Bioorg Med Chem Lett 2002; 12:3403-5. [PMID: 12419371 DOI: 10.1016/s0960-894x(02)00764-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Core-modified sordaricin derivatives were prepared via biotransformation followed by chemical modification and tested for antifungal activity. The antifungal activity proved to be very sensitive to modifications in the sterics and/or lipophilicity of the diterpene skeleton. Introduction of polar groups such as hydroxyl in the diterpene core results in loss of potency while small and lipophilic groups such as fluorine and the 7,8-olefin are well tolerated.
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Affiliation(s)
- Alicia Regueiro-Ren
- Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, CT 06492, USA.
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36
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Serrano-Wu MH, St Laurent DR, Chen Y, Huang S, Lam KR, Matson JA, Mazzucco CE, Stickle TM, Tully TP, Wong HS, Vyas DM, Balasubramanian BN. Sordarin oxazepine derivatives as potent antifungal agents. Bioorg Med Chem Lett 2002; 12:2757-60. [PMID: 12217370 DOI: 10.1016/s0960-894x(02)00529-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The synthesis and biological activity of sordarin oxazepine derivatives are described. The key step features a regioselective oxidation of an unprotected triol followed by double reductive amination to afford the ring-closed products. The spectrum of antifungal activity for these novel derivatives includes coverage of Candida albicans, Candida glabrata, and Cryptococcus neoformans.
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Affiliation(s)
- Michael H Serrano-Wu
- Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, CT 06492, USA.
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37
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Sturtevant J. Translation elongation-3-like factors: are they rational antifungal targets? Expert Opin Ther Targets 2002; 6:545-53. [PMID: 12387678 DOI: 10.1517/14728222.6.5.545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The occurrence of fungal infection has escalated significantly in recent years and is expected to continue to increase for the foreseeable future. Unfortunately, only a limited number of antifungal drugs are currently available partially due to a lack of suitable targets. The most commonly used antifungals target the same molecule in the cell membrane and, while efficacious, are either extremely toxic or susceptible to resistance. This article examines elongation factor-3, which is unique to fungi and essential for fungal cell survival and, thus, an attractive antifungal target. A search for inhibitors of this 'perfect target' led to identification of compounds (sordarins) which inhibited elongation factor-2, a protein with a mammalian homologue. Molecular analysis demonstrated why sordarins can specifically act against fungal elongation factor-2. This data questions the validity of pursuing genes as targets only if they are unique to fungi. Proteins that are homologous to elongation factor-3 are also discussed. The advances in molecular techniques and bioinformatics will allow the re-evaluation of targets previously thought to be unattractive. In addition, molecular genetics provides new and novel information on cellular processes that can potentially introduce new targets.
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Affiliation(s)
- Joy Sturtevant
- Dept of Microbiology, Immunology and Parasitology, Center of Excellence in Oral and Craniofacial Biology, LSU Health Sciences Center - School of Dentistry, 1100 Florida Ave, Box F8-130, New Orleans, LA 70119, USA.
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38
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Arai M, Kaneko S, Konosu T. A novel approach to the stereoselective semi-synthesis of GM-237354 by employing a highly β-selective glycosylation. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01531-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Goss Kinzy T, Harger JW, Carr-Schmid A, Kwon J, Shastry M, Justice M, Dinman JD. New targets for antivirals: the ribosomal A-site and the factors that interact with it. Virology 2002; 300:60-70. [PMID: 12202206 DOI: 10.1006/viro.2002.1567] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many viruses use programmed -1 ribosomal frameshifting to ensure the correct ratio of viral structural to enzymatic proteins. Alteration of frameshift efficiencies changes these ratios, in turn inhibiting viral particle assembly and virus propagation. Previous studies determined that anisomycin, a peptidyl transferase inhibitor, specifically inhibited -1 frameshifting and the ability of yeast cells to propagate the L-A and M(1) dsRNA viruses (J. D. Dinman, M. J. Ruiz-Echevarria, K. Czaplinski, and S. W. Peltz, 1997, Proc. Natl. Acad. Sci. USA 94, 6606-6611). Here we show that preussin, a pyrollidine that is structurally similar to anisomycin (R. E. Schwartz, J. Liesch, O. Hensens, L. Zitano, S. Honeycutt, G. Garrity, R. A. Fromtling, J. Onishi, and R. Monaghan, 1988. J. Antibiot. (Tokyo) 41, 1774--1779), also inhibits -1 programmed ribosomal frameshifting and virus propagation by acting at the same site or through the same mechanism as anisomycin. Since anisomycin is known to assert its effect at the ribosomal A-site, we undertook a pharmacogenetic analysis of mutants of trans-acting eukaryotic elongation factors (eEFs) that function at this region of the ribosome. Among mutants of eEF1A, a correlation is observed between resistance/susceptibility profiles to preussin and anisomycin, and these in turn correlate with programmed -1 ribosomal frameshifting efficiencies and killer virus phenotypes. Among mutants of eEF2, the extent of resistance to preussin correlates with resistance to sordarin, an eEF2 inhibitor. These results suggest that structural features associated with the ribosomal A-site and with the trans-acting factors that interact with it may present a new set of molecular targets for the rational design of antiviral compounds.
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Affiliation(s)
- Terri Goss Kinzy
- Department of Molecular Genetics and Microbiology, UMDNJ/Rutgers Universities, UMDNJ Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854, USA
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40
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Kaneko S, Arai M, Uchida T, Harasaki T, Fukuoka T, Konosu T. Synthesis and evaluation of N-substituted 1,4-oxazepanyl Sordaricins as selective fungal EF-2 inhibitors. Bioorg Med Chem Lett 2002; 12:1705-8. [PMID: 12067542 DOI: 10.1016/s0960-894x(02)00290-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sordaricin analogues possessing 6-methoxy-7-methyl-1,4-oxazepane moiety instead of the sugar part were synthesized and evaluated. It was found that N-substituents on the oxazepane ring had influence on biological activity. In particular, N-(2-methylpropenyl) derivative 12p exhibited potent in vitro antifungal activity. Furthermore, 12p maintained significant activity (MIC 0.25 microg/mL) against Candida albicans SANK51486 even in the presence of 20% horse serum.
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Affiliation(s)
- Satoru Kaneko
- Medicinal Chemistry Research Laboratories, Sankyo Co., Ltd., 2-58, Hiromachi 1-chome, Shinagawa-ku, Tokyo 140-8710, Japan.
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41
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Serrano-Wu MH, St Laurent DR, Mazzucco CE, Stickle TM, Barrett JF, Vyas DM, Balasubramanian BN. Oxime derivatives of sordaricin as potent antifungal agents. Bioorg Med Chem Lett 2002; 12:943-6. [PMID: 11958999 DOI: 10.1016/s0960-894x(02)00054-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Oxime derivatives of the sordarin aglycone have been identified as potent antifungal agents. The in vitro spectrum of activity includes coverage against Candida albicans and Candida glabrata with MICs as low as 0.06 microg/mL. The antifungal activity was established to be exquisitely sensitive to the spatial orientation of the lipophilic side chains.
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Affiliation(s)
- Michael H Serrano-Wu
- Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06492, USA.
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42
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Herreros E, Almela MJ, Lozano S, Gomez de las Heras F, Gargallo-Viola D. Antifungal activities and cytotoxicity studies of six new azasordarins. Antimicrob Agents Chemother 2001; 45:3132-9. [PMID: 11600368 PMCID: PMC90794 DOI: 10.1128/aac.45.11.3132-3139.2001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
GW 471552, GW 471558, GW 479821, GW 515716, GW 570009, and GW 587270 are members of a new family of sordarin derivatives called azasordarins. The in vitro activities of these compounds were evaluated against clinical isolates of yeasts, including Candida albicans, Candida non-albicans, and Cryptococcus neoformans strains. Activities against Pneumocystis carinii, Aspergillus spp., less common molds, and dermatophytes were also investigated. Azasordarin derivatives displayed significant activities against the most clinically important Candida species, with the exception of C. krusei. Against C. albicans, including fluconazole-resistant strains, MICs at which 90% of the isolates tested are inhibited (MIC(90)s) were 0.002 microg/ml with GW 479821, 0.015 microg/ml with GW 515716 and GW 587270, and 0.06 microg/ml with GW 471552, GW 471558, and GW 570009. The MIC(90)s of GW 471552, GW 471558, GW 479821, GW 515716, GW 570009, and GW 587270 were 0.12, 0.12, 0.03, 0.06, 0.12, and 0.06 microg/ml, respectively, against C. tropicalis and 4, 0.25, 0.06, 0.25, 0.5, and 0.5 microg/ml, respectively, against C. glabrata. In addition, some azasordarin derivatives (GW 479821, GW 515716, GW 570009, and GW 58720) were active against C. parapsilosis, with MIC(90)s of 2, 4, 4, and 1 microg/ml, respectively. The compounds were extremely potent against P. carinii, showing 50% inhibitory concentrations of <or=0.001 microg/ml. However Cryptococcus neoformans was resistant to all compounds tested (MIC > 16 microg/ml). These azasordarin derivatives also showed significant activity against emerging fungal pathogens, which affect immunocompromised patients, such as Rhizopus arrhizus, Blastoschizomyces capitatus, and Geotrichum clavatum. Against these organisms, the MICs of GW 587270 ranged from 0.12 to 1 microg/ml, those of GW 479821 and GW 515716 ranged from 0.12 to 2 microg/ml, and those of GW 570009 ranged from 0.12 to 4 microg/ml. Against Fusarium oxysporum, Scedosporium apiospermum, Absidia corymbifera, Cunninghamella bertholletiae, and dermatophytes, GW 587270 was the most active compound, with MICs ranging from 4 to 16 microg/ml. Against Aspergillus spp., the MICs of the compounds tested were higher than 16 microg/ml. The in vitro selectivity of azasordarins was investigated by cytotoxicity studies performed with five cell lines and primary hepatocytes. Concentrations of compound required to achieve 50% inhibition of the parameter considered (Tox(50)s) of GW 570009, GW 587270, GW 479281, and GW 515716 in the cell lines ranged from 60 to 96, 49 to 62, 24 to 36, and 16 to 38 microg/ml, respectively. The cytotoxicity values of GW 471552 and GW 471558 were >100 microg/ml for all cell lines tested. Tox(50)s on hepatocytes were in the following order: GW 471558 > GW 471552 > GW 570009 > GW 587270 > GW 515716 > GW 479821, with values ranging from higher than 100 microg/ml to 23 microg/ml. The cytotoxicity results obtained with fully metabolizing rat hepatocytes were in total agreement with those obtained with cell lines. In summary, the in vitro activities against important pathogenic fungi and the selectivity demonstrated in mammalian cell lines justify additional studies to determine the clinical usefulness of azasordarins.
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Affiliation(s)
- E Herreros
- Glaxo Smithkline, 28760 Tres Cantos, Madrid, Spain
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43
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Domínguez JM, Martin JJ. Identification of a putative sordarin binding site in Candida albicans elongation factor 2 by photoaffinity labeling. J Biol Chem 2001; 276:31402-7. [PMID: 11402051 DOI: 10.1074/jbc.m104183200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Candida albicans EF-2 binds sordarin to a single class of binding sites with K(d) = 1.26 microm. Equimolar mixtures of EF-2 and ribosomes, in the presence of a non-hydrolyzable GTP analog, reveal two classes of high affinity sordarin binding sites with K(d) = 0.7 and 41.5 nm, probably due to the existence of two ribosome populations. Photoaffinity labeling of C. albicans EF-2 in the absence of ribosomes has been performed with [(14)C]GM258383, a photoactivatable sordarin derivative. Labeling is saturable and can be considered specific, because it can be prevented with another sordarin analog. The fragment Gln(224)-Lys(232) has been identified as the modified peptide within the EF-2 sequence, Lys(228) being the residue to which the photoprobe was linked. This fragment is included within the G"-subdomain of EF-2. These results are discussed in the light of the high sordarin specificity toward fungal systems.
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Affiliation(s)
- J M Domínguez
- Research Department, GlaxoSmithKline S. A. PTM, C/Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain.
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44
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Harger JW, Meskauskas A, Nielsen J, Justice MC, Dinman JD. Ty1 retrotransposition and programmed +1 ribosomal frameshifting require the integrity of the protein synthetic translocation step. Virology 2001; 286:216-24. [PMID: 11448174 DOI: 10.1006/viro.2001.0997] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Programmed ribosomal frameshifting is utilized by a number of RNA viruses to ensure the correct ratio of viral structural to enzymatic proteins for viral particle assembly. Altering frameshifting efficiencies upsets this ratio, inhibiting virus propagation. Two yeast viruses that induce host cell ribosomes to shift translational reading frame were used as tools to explore the interactions between viruses and host cellular protein synthetic machinery. Previous studies showed that the ribosome-inactivating protein pokeweed antiviral protein specifically inhibited propagation of the Ty1 retrotransposable element of yeast as a consequence of inhibition of programmed +1 ribosomal frameshifting. Here, complementary genetic and pharmacological approaches were employed to test whether inhibition of Ty1 retrotransposition is a general feature of alterations in the translocation step of elongation and +1 frameshifting. The results demonstrate that cells harboring a variety of mutant alleles of two host-encoded proteins that are involved in translocation, eukaryotic elongation factor-2 and the ribosome-associated protein RPP0, have Ty1 propagation defects. We also show that sordarin, a fungus-specific inhibitor of eEF-2 function, specifically inhibits programmed +1 ribosomal frameshifting and Ty1 retrotransposition. These findings serve to link inhibition of Ty1 retrotransposition and +1 frameshifting to changes in the translocation step of elongation.
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Affiliation(s)
- J W Harger
- Department of Molecular Genetics and Microbiology, Graduate Program in Molecular Biosciences at UMDNJ/Rutgers Universities, The Cancer Institute of New Jersey, Piscataway, New Jersey 08854, USA
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45
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Shastry M, Nielsen J, Ku T, Hsu MJ, Liberator P, Anderson J, Schmatz D, Justice MC. Species-specific inhibition of fungal protein synthesis by sordarin: identification of a sordarin-specificity region in eukaryotic elongation factor 2. MICROBIOLOGY (READING, ENGLAND) 2001; 147:383-390. [PMID: 11158355 DOI: 10.1099/00221287-147-2-383] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The sordarin class of natural products selectively inhibits fungal protein synthesis by impairing the function of eukaryotic elongation factor 2 (eEF2). Mutations in Saccharomyces cerevisiae eEF2 or the ribosomal stalk protein rpP0 can confer resistance to sordarin, although eEF2 is the major determinant of sordarin specificity. It has been shown previously that sordarin specifically binds S. cerevisiae eEF2 while there is no detectable binding to eEF2 from plants or mammals, despite the high level of amino acid sequence conservation among these proteins. In both whole-cell assays and in vitro translation assays, the efficacy of sordarin varies among different species of pathogenic fungi. To investigate the basis of sordarin's fungal selectivity, eEF2 has been cloned and characterized from several sordarin-sensitive and -insensitive fungal species. Results from in vivo expression of Candida species eEF2s in S. cerevisiae and in vitro translation and growth inhibition assays using hybrid S. cerevisiae eEF2 proteins demonstrate that three amino acid residues within eEF2 account for the selectivity of this class of compounds. It is also shown that the corresponding residues at these positions in human eEF2 are sufficient to confer sordarin insensitivity to S. cerevisiae identical to that observed with mammalian eEF2.
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Affiliation(s)
- Mythili Shastry
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Jennifer Nielsen
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Theresa Ku
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Ming-Jo Hsu
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Paul Liberator
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Jennifer Anderson
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Dennis Schmatz
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
| | - Michael C Justice
- Department of Animal Health, Merck Research Laboratories, PO Box 2000, Rahway, NJ 07065, USA1
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46
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Briones C, Ballesta JP. Conformational changes induced in the Saccharomyces cerevisiae GTPase-associated rRNA by ribosomal stalk components and a translocation inhibitor. Nucleic Acids Res 2000; 28:4497-505. [PMID: 11071938 PMCID: PMC113874 DOI: 10.1093/nar/28.22.4497] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The yeast ribosomal GTPase associated center is made of parts of the 26S rRNA domains II and VI, and a number of proteins including P0, P1alpha, P1beta, P2alpha, P2beta and L12. Mapping of the rRNA neighborhood of the proteins was performed by footprinting in ribosomes from yeast strains lacking different GTPase components. The absence of protein P0 dramatically increases the sensitivity of the defective ribosome to degradation hampering the RNA footprinting. In ribosomes lacking the P1/P2 complex, protection of a number of nucleotides is detected around positions 840, 880, 1100, 1220-1280 and 1350 in domain II as well as in several positions in the domain VI alpha-sarcin region. The protection pattern resembles the one reported for the interaction of elongation factors in bacterial systems. The results exclude a direct interaction of these proteins with the rRNA and are compatible with an increase in the ribosome affinity for EF-2 in the absence of the acidic P proteins. Interestingly, a sordarin derivative inhibitor of EF-2 causes an opposite effect, increasing the reactivity in positions protected by the absence of P1/P2. Similarly, a deficiency in protein L12 exposes nucleotides G1235, G1242, A1262, A1269, A1270 and A1272 to chemical modification, thus situating the protein binding site in the most conserved part of the 26S rRNA, equivalent to the bacterial protein L11 binding site.
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Affiliation(s)
- C Briones
- Centro de Biología Molecular 'Severo Ochoa', Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid, Canto Blanco, 28049 Madrid, Spain
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47
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Gomez-Lorenzo MG, Spahn CM, Agrawal RK, Grassucci RA, Penczek P, Chakraburtty K, Ballesta JP, Lavandera JL, Garcia-Bustos JF, Frank J. Three-dimensional cryo-electron microscopy localization of EF2 in the Saccharomyces cerevisiae 80S ribosome at 17.5 A resolution. EMBO J 2000; 19:2710-8. [PMID: 10835368 PMCID: PMC212750 DOI: 10.1093/emboj/19.11.2710] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2000] [Revised: 03/28/2000] [Accepted: 04/04/2000] [Indexed: 11/14/2022] Open
Abstract
Using a sordarin derivative, an antifungal drug, it was possible to determine the structure of a eukaryotic ribosome small middle dotEF2 complex at 17.5 A resolution by three-dimensional (3D) cryo-electron microscopy. EF2 is directly visible in the 3D map and the overall arrangement of the complex from Saccharomyces cerevisiae corresponds to that previously seen in Escherichia coli. However, pronounced differences were found in two prominent regions. First, in the yeast system the interaction between the elongation factor and the stalk region of the large subunit is much more extensive. Secondly, domain IV of EF2 contains additional mass that appears to interact with the head of the 40S subunit and the region of the main bridge of the 60S subunit. The shape and position of domain IV of EF2 suggest that it might interact directly with P-site-bound tRNA.
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Affiliation(s)
- M G Gomez-Lorenzo
- Health Research Inc. at Wadsworth Center, State University of New York at Albany, Empire State Plaza, Albany, NY 12201-0509, USA
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