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Dmitriev SE, Vladimirov DO, Lashkevich KA. A Quick Guide to Small-Molecule Inhibitors of Eukaryotic Protein Synthesis. BIOCHEMISTRY (MOSCOW) 2021; 85:1389-1421. [PMID: 33280581 PMCID: PMC7689648 DOI: 10.1134/s0006297920110097] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Eukaryotic ribosome and cap-dependent translation are attractive targets in the antitumor, antiviral, anti-inflammatory, and antiparasitic therapies. Currently, a broad array of small-molecule drugs is known that specifically inhibit protein synthesis in eukaryotic cells. Many of them are well-studied ribosome-targeting antibiotics that block translocation, the peptidyl transferase center or the polypeptide exit tunnel, modulate the binding of translation machinery components to the ribosome, and induce miscoding, premature termination or stop codon readthrough. Such inhibitors are widely used as anticancer, anthelmintic and antifungal agents in medicine, as well as fungicides in agriculture. Chemicals that affect the accuracy of stop codon recognition are promising drugs for the nonsense suppression therapy of hereditary diseases and restoration of tumor suppressor function in cancer cells. Other compounds inhibit aminoacyl-tRNA synthetases, translation factors, and components of translation-associated signaling pathways, including mTOR kinase. Some of them have antidepressant, immunosuppressive and geroprotective properties. Translation inhibitors are also used in research for gene expression analysis by ribosome profiling, as well as in cell culture techniques. In this article, we review well-studied and less known inhibitors of eukaryotic protein synthesis (with the exception of mitochondrial and plastid translation) classified by their targets and briefly describe the action mechanisms of these compounds. We also present a continuously updated database (http://eupsic.belozersky.msu.ru/) that currently contains information on 370 inhibitors of eukaryotic protein synthesis.
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Affiliation(s)
- S E Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234, Russia. .,Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119234, Russia.,Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - D O Vladimirov
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - K A Lashkevich
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
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Sheridan CM, Garcia VE, Ahyong V, DeRisi JL. The Plasmodium falciparum cytoplasmic translation apparatus: a promising therapeutic target not yet exploited by clinically approved anti-malarials. Malar J 2018; 17:465. [PMID: 30541569 PMCID: PMC6292128 DOI: 10.1186/s12936-018-2616-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/06/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The continued spectre of resistance to existing anti-malarials necessitates the pursuit of novel targets and mechanisms of action for drug development. One class of promising targets consists of the 80S ribosome and its associated components comprising the parasite translational apparatus. Development of translation-targeting therapeutics requires a greater understanding of protein synthesis and its regulation in the malaria parasite. Research in this area has been limited by the lack of appropriate experimental methods, particularly a direct measure of parasite translation. METHODS An in vitro method directly measuring translation in whole-cell extracts from the malaria parasite Plasmodium falciparum, the PfIVT assay, and a historically-utilized indirect measure of translation, S35-radiolabel incorporation, were compared utilizing a large panel of known translation inhibitors as well as anti-malarial drugs. RESULTS Here, an extensive pharmacologic assessment of the PfIVT assay is presented, using a wide range of known inhibitors demonstrating its utility for studying activity of both ribosomal and non-ribosomal elements directly involved in translation. Further, the superiority of this assay over a historically utilized indirect measure of translation, S35-radiolabel incorporation, is demonstrated. Additionally, the PfIVT assay is utilized to investigate a panel of clinically approved anti-malarial drugs, many with unknown or unclear mechanisms of action, and show that none inhibit translation, reaffirming Plasmodium translation to be a viable alternative drug target. Within this set, mefloquine is unambiguously found to lack translation inhibition activity, despite having been recently mischaracterized as a ribosomal inhibitor. CONCLUSIONS This work exploits a direct and reproducible assay for measuring P. falciparum translation, demonstrating its value in the continued study of protein synthesis in malaria and its inhibition as a drug target.
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Affiliation(s)
- Christine Moore Sheridan
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Valentina E Garcia
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Vida Ahyong
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Joseph L DeRisi
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, USA.
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Wu M, Xiao H, Ren W, Yin J, Tan B, Liu G, Li L, Nyachoti CM, Xiong X, Wu G. Therapeutic effects of glutamic acid in piglets challenged with deoxynivalenol. PLoS One 2014; 9:e100591. [PMID: 24984001 PMCID: PMC4077692 DOI: 10.1371/journal.pone.0100591] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/26/2014] [Indexed: 12/30/2022] Open
Abstract
The mycotoxin deoxynivalenol (DON), one of the most common food contaminants, primarily targets the gastrointestinal tract to affect animal and human health. This study was conducted to examine the protective function of glutamic acid on intestinal injury and oxidative stress caused by DON in piglets. Twenty-eight piglets were assigned randomly into 4 dietary treatments (7 pigs/treatment): 1) uncontaminated control diet (NC), 2) NC+DON at 4 mg/kg (DON), 3) NC+2% glutamic acid (GLU), and 4) NC+2% glutamic acid + DON at 4 mg/kg (DG). At day 15, 30 and 37, blood samples were collected to determine serum concentrations of CAT (catalase), T-AOC (total antioxidant capacity), H2O2 (hydrogen peroxide), NO (nitric oxide), MDA (maleic dialdehyde), DAO (diamine oxidase) and D-lactate. Intestinal morphology, and the activation of Akt/mTOR/4EBP1 signal pathway, as well as the concentrations of H2O2, MDA, and DAO in kidney, liver and small intestine, were analyzed at day 37. Results showed that DON significantly (P<0.05) induced oxidative stress in piglets, while this stress was remarkably reduced with glutamic acid supplementation according to the change of oxidative parameters in blood and tissues. Meanwhile, DON caused obvious intestinal injury from microscopic observations and permeability indicators, which was alleviated by glutamic acid supplementation. Moreover, the inhibition of DON on Akt/mTOR/4EBP1 signal pathway was reduced by glutamic acid supplementation. Collectively, these data suggest that glutamic acid may be a useful nutritional regulator for DON-induced damage manifested as oxidative stress, intestinal injury and signaling inhibition.
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Affiliation(s)
- Miaomiao Wu
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hao Xiao
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenkai Ren
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jie Yin
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bie Tan
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
| | - Gang Liu
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
| | - Lili Li
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
| | | | - Xia Xiong
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
- * E-mail:
| | - Guoyao Wu
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Scienses, Changsha, Hunan, China
- Department of Animal Science, Texas A&M University, College Station, Texas, United State of America
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Kobayashi Y, Mizunuma M, Osada H, Miyakawa T. Identification ofSaccharomyces cerevisiaeRibosomal Protein L3 as a Target of Curvularol, a G1-Specific Inhibitor of Mammalian Cells. Biosci Biotechnol Biochem 2014; 70:2451-9. [PMID: 17031058 DOI: 10.1271/bbb.60186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The cellular target of curvularol, a G1-specific cell-cycle inhibitor of mammalian cells, was identified by a genetic approach in Saccharomyces cerevisiae. Since the wild-type W303 strain was highly resistant to curvularol, a drug hypersensitive parental strain was constructed in which various genes implicated in general drug resistance had been disrupted. Curvularol resistant mutants were isolated, and strains that exhibited a semi-dominant, curvularol-specific resistance phenotype were selected. All five strains examined were classified into a single genetic complementation group designated YCR1. A mutant gene responsible for curvularol resistance was identified as an allele of the RPL3 gene encoding the ribosomal protein L3. Sequence analysis of the mutant genes revealed that Trp255Cys and Trp255Leu substitutions of Rpl3p are responsible for curvularol resistance. Rpl3p mutants in which Trp255 residue was replaced by other amino acids were constructed. All of these replacements led to varying degrees of increased resistance to curvularol and growth defects.
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Affiliation(s)
- Yoshifumi Kobayashi
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter (AdSM), Hiroshima University, Japan
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Jossé L, Li X, Coker RD, Gourlay CW, Evans IH. Transcriptomic and phenotypic analysis of the effects of T-2 toxin on Saccharomyces cerevisiae: evidence of mitochondrial involvement. FEMS Yeast Res 2010; 11:133-50. [DOI: 10.1111/j.1567-1364.2010.00699.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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A genome-wide screen in Saccharomyces cerevisiae reveals a critical role for the mitochondria in the toxicity of a trichothecene mycotoxin. Proc Natl Acad Sci U S A 2009; 106:21883-8. [PMID: 20007368 DOI: 10.1073/pnas.0909777106] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Trichothecene mycotoxins synthesized by Fusarium species are potent inhibitors of eukaryotic translation. They are encountered in both the environment and in food, posing a threat to human and animal health. They have diverse roles in the cell that are not limited to the inhibition of protein synthesis. To understand the trichothecene mechanism of action, we screened the yeast knockout library to identify genes whose deletion confers resistance to trichothecin (Tcin). The largest group of resistant strains affected mitochondrial function, suggesting a role for fully active mitochondria in trichothecene toxicity. Tcin inhibited mitochondrial translation in the wild-type strain to a greater extent than in the most resistant strains, implicating mitochondrial translation as a previously unrecognized site of action. The Tcin-resistant strains were cross-resistant to anisomycin and chloramphenicol, suggesting that Tcin targets the peptidyltransferase center of mitochondrial ribosomes. Tcin-induced cell death was partially rescued by mutants that regulate mitochondrial fusion and maintenance of the tubular morphology of mitochondria. Treatment of yeast cells with Tcin led to the fragmentation of the tubular mitochondrial network, supporting a role for Tcin in disruption of mitochondrial membrane morphology. These results provide genome-wide insight into the mode of action of trichothecene mycotoxins and uncover a critical role for mitochondrial translation and membrane maintenance in their toxicity.
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Ma YY, Guo HW. Mini-review of studies on the carcinogenicity of deoxynivalenol. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2008; 25:1-9. [PMID: 21783829 DOI: 10.1016/j.etap.2007.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 09/25/2007] [Accepted: 09/28/2007] [Indexed: 05/31/2023]
Abstract
The purpose of this article is to make a summary of the information regarding the researches on the carcinogenicity of DON and to discuss implications on future researches. Publications of experiments were collected through databases, experts, previous reviews, citation tracking. To guarantee the quality of the studies included in this review, we set up different criteria for different kinds of studies. As a result, all three gene mutation assays had negative results; all four chromosome aberration tests had positive results, even one of which had a dose-response effect; six from ten DNA damage/repair tests had positive results and tow of those six ones had dose-response effects; one mammalian cell malignant transformation assay showed positive result; two from three medium-term and long-term carcinogenicity studies had negative results; all six epidemiologic studies had positive results. In conclusion, DON cannot be classified as carcinogen according to these tests and studies because the results from the short-term in vitro studies were quite contradictory, and the results from the medium-term and long-term in vivo studies and from the epidemiological studies in humane beings were invalid due to their poor methodology quality. It is necessary to make more and better researches on the carcinogenicity of DON considering its chronic and low level of exposure to the human beings.
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Affiliation(s)
- Yi Yi Ma
- School of Public Health, Fudan University, Shanghai, China
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Kouadio JH, Mobio TA, Baudrimont I, Moukha S, Dano SD, Creppy EE. Comparative study of cytotoxicity and oxidative stress induced by deoxynivalenol, zearalenone or fumonisin B1 in human intestinal cell line Caco-2. Toxicology 2005; 213:56-65. [PMID: 16019124 DOI: 10.1016/j.tox.2005.05.010] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 02/21/2005] [Accepted: 05/12/2005] [Indexed: 11/24/2022]
Abstract
Fusarium species infestations of cereals crops occur worldwide. Fusarium toxins such as, deoxynivalenol (DON), zearalenone (ZEN) and fumonisin B1 (FB1) have been shown to cause diverse toxic effects in animals and also suspected of disease causation in humans. From the literature and mechanistic point of view, DON binds to the ribosomal peptidyl-transferase and inhibits protein synthesis specifically and DNA synthesis consequently. ZEN known to be genotoxic, binds to 17-beta-estradiol receptors, induces lipid peroxidation, cell death and inhibits protein and DNA synthesis. FB1 disrupts sphingolipid metabolism, induces lipid peroxidation altering the cell membrane and causing cell death. We intended to compare DON, ZEN and FB1 (1-150 microM) cytotoxic effect and the pathways leading to cell death and related to oxidative stress and macromolecules syntheses in a human intestinal cell line in order to tentatively classify them according to their respective potential toxicity. The comparison reveals that all three mycotoxins bear, at variable degree, the capability of inducing lipid peroxidation (MDA production) and could be classified above 10 microM in decreasing potency order FB1>DON>ZEN. This effect seems to be related to their common target that is the mitochondria as revealed by MTT test and seemingly not related to sphingoids accumulation concerning FB1. DON and ZEN also adversely affect lysosomes in contrast to FB1. The three mycotoxins inhibit protein synthesis with respective IC50 of 5, 8.8 and 19 microM for DON, FB1 and ZEN confirming that protein synthesis is a specific target of DON. DNA synthesis is inhibited by DON, ZEN and FB1 with respective IC50 of 1.7, 10 and 20 microM. However at higher concentrations DNA synthesis seems to be restored for FB1 and DON suggesting a promoter activity. Altogether the potency of the three mycotoxins in macromolecules inhibition is DON>ZEN>FB1 in Caco-2 cells. It appears then that FB1 acts rather through lipid peroxidation while DON affects rather DNA and protein synthesis.
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Affiliation(s)
- James H Kouadio
- Toxicology Department, University of Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux, France
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Novac O, Guenier AS, Pelletier J. Inhibitors of protein synthesis identified by a high throughput multiplexed translation screen. Nucleic Acids Res 2004; 32:902-15. [PMID: 14769948 PMCID: PMC373382 DOI: 10.1093/nar/gkh235] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The use of small molecule inhibitors of cellular processes is a powerful approach to understanding gene function that complements the genetic approach. We have designed a high throughput screen to identify new inhibitors of eukaryotic protein synthesis. We used a bicistronic mRNA reporter to multiplex our assay and simultaneously screen for inhibitors of cap-dependent initiation, internal initiation and translation elongation/termination. Functional screening of >90 000 compounds in an in vitro translation reaction identified 36 inhibitors, 14 of which are known inhibitors of translation and 18 of which are nucleic acid-binding ligands. Our results indicate that intercalators constitute a large class of protein synthesis inhibitors. Four non-intercalating compounds were identified, three of which block elongation and one of which inhibits initiation. The novel inhibitor of initiation affects 5' end-mediated initiation, as well as translation initiated from picornaviral IRESs, but does not significantly affect internal initiation from the hepatitis C virus 5'-untranslated region. This compound should be useful for delineating differences in mechanism of initiation among IRESs.
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Affiliation(s)
- Olivia Novac
- Department of Biochemistry, McGill Cancer Center, 3655 Promenade Sir William Osler, McIntyre Medical Sciences Building, McGill University, Montreal, Quebec H3G 1Y6, Canada
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Chung YJ, Jarvis B, Pestka J. Modulation of lipopolysaccharide-induced proinflammatory cytokine production by satratoxins and other macrocyclic trichothecenes in the murine macrophage. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2003; 66:379-391. [PMID: 12554543 DOI: 10.1080/15287390306363] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The satratoxins and other macrocyclic trichothecene mycotoxins are produced by Stachybotrys, a mold that is often found in water-damaged dwellings and office buildings. To test the potential immunomodulatory effects of these mycotoxins, RAW 264.7 murine macrophage cells were treated with various concentrations of satratoxin G (SG), isosatratoxin F (iSF), satratoxin H (SH), roridin A (RA), and verrucarin A (VA) for 48 h in the presence or absence of suboptimal concentra-tion of lipopolysaccharide (LPS, 50 ng/ml), and tumor necrosis factor-alpha (TNF-alpha ) and interleukin-6 (IL-6) production were assayed by enzyme-linked immunosorbent assay (ELISA). In LPS-stimulated cultures, TNF-alpha supernatant concentrations were significantly increased in the presence of 2.5, 2.5, and 1 ng/ml of SG, SH, and RA, respectively, whereas IL-6 concentrations were not affected by the same concentrations these macrocyclic trichothecenes. When cells that were treated with LPS and SG (2.5 ng/ml) were evaluated by real-time polymerase chain reaction (PCR),TNF-alpha mRNA was found to increase at 24, 36, and 48 h compared to control cells. At higher concentrations, cytokine production and cell viability were markedly impaired in LPS-stimulated cells. Without LPS stimulation, neither TNF-alpha, nor IL-6 was induced. These results indicate that low concentrations of macrocyclic trichothecenes superinduce expression of TNF-alpha, whereas higher concentrations of these toxins are cytotoxic and concurrently reduce cytokine production. The capacity of satratoxins and other macrocyclic trichothecenes to alter cytokine production may play an etiologic role in outbreaks of Stachybotrys-associated human illnesses.
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Affiliation(s)
- Yong-Joo Chung
- Department of Food Science and Human Nutrition, Institute for Environmental Toxicology, Michigan State University, East Lansing, Michigan 48824-224, USA
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Shifrin VI, Anderson P. Trichothecene mycotoxins trigger a ribotoxic stress response that activates c-Jun N-terminal kinase and p38 mitogen-activated protein kinase and induces apoptosis. J Biol Chem 1999; 274:13985-92. [PMID: 10318810 DOI: 10.1074/jbc.274.20.13985] [Citation(s) in RCA: 310] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The trichothecene family of mycotoxins inhibit protein synthesis by binding to the ribosomal peptidyltransferase site. Inhibitors of the peptidyltransferase reaction (e.g. anisomycin) can trigger a ribotoxic stress response that activates c-Jun N-terminal kinase (JNK)/p38 mitogen-activated protein kinases, components of a signaling cascade that regulates cell survival in response to stress. We have found that selected trichothecenes strongly activate JNK/p38 kinases and induce rapid apoptosis in Jurkat T cells. Although the ability of individual trichothecenes to inhibit protein synthesis and activate JNK/p38 kinases are dissociable, both effects contribute to the induction of apoptosis. Among trichothecenes that strongly activate JNK/p38 kinases, induction of apoptosis increases linearly with inhibition of protein synthesis. Among trichothecenes that strongly inhibit protein synthesis, induction of apoptosis increases linearly with activation of JNK/p38 kinases. Trichothecenes that inhibit protein synthesis without activating JNK/p38 kinases inhibit the function (i.e. activation of JNK/p38 kinases and induction of apoptosis) of apoptotic trichothecenes and anisomycin. Harringtonine, a structurally unrelated protein synthesis inhibitor that competes with trichothecenes (and anisomycin) for ribosome binding, also inhibits the activation of JNK/p38 kinases and induction of apoptosis by trichothecenes and anisomycin. Taken together, these results implicate the peptidyltransferase site as a regulator of both JNK/p38 kinase activation and apoptosis.
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Affiliation(s)
- V I Shifrin
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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Holtorf H, Schöb H, Kunz C, Waldvogel R, Meins F. Stochastic and nonstochastic post-transcriptional silencing of chitinase and beta-1,3-glucanase genes involves increased RNA turnover-possible role for ribosome-independent RNA degradation. THE PLANT CELL 1999; 11:471-84. [PMID: 10072405 PMCID: PMC144180 DOI: 10.1105/tpc.11.3.471] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Stochastic and nonstochastic post-transcriptional gene silencing (PTGS) in Nicotiana sylvestris plants carrying tobacco class I chitinase (CHN) and beta-1,3-glucanase transgenes differs in incidence, stability, and pattern of expression. Measurements with inhibitors of RNA synthesis (cordycepin, actinomycin D, and alpha-amanitin) showed that both forms of PTGS are associated with increased sequence-specific degradation of transcripts, suggesting that increased RNA turnover may be a general feature of PTGS. The protein synthesis inhibitors cycloheximide and verrucarin A did not inhibit degradation of CHN RNA targeted for PTGS, confirming that PTGS-related RNA degradation does not depend on ongoing protein synthesis. Because verrucarin A, unlike cycloheximide, dissociates mRNA from ribosomes, our results also suggest that ribosome-associated RNA degradation pathways may not be involved in CHN PTGS.
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Affiliation(s)
- H Holtorf
- Friedrich Miescher Institute, P.O. Box 2543, CH-4002 Basel, Switzerland
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Abstract
The effects of steroids on the association of T-2 toxin with cultured cells were evaluated. Preincubating cells with certain steroids led to a time- and concentration-related increase in total T-2-cell association. At maximally effective concentrations, the increase in association was 300-500%. This effect required a preincubation at 37 degrees C for a minimum of 10 min and was completely reversible after 20-30 min. Steroid treatment increased the rate of toxin-cell association and decreased the rate of dissociation. The effect was elicited by progesterone, estradiol, testosterone and diethylstilbestrol, but not by several other steroids tested. Binding of T-2 to isolated ribosomes was not altered by the steroids. We speculated that steroids somehow alter the state of ribosomal aggregation or assembly such that more toxin can bind after entering the cell.
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Affiliation(s)
- J L Middlebrook
- Toxinology Division, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702-5011
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Kuti JO, Jarvis BB, Mokhtari-Rejali N, Bean GA. Allelochemical regulation of reproduction and seed germination of two BrazilianBaccharis species by phytotoxic trichothecenes. J Chem Ecol 1990; 16:3441-53. [DOI: 10.1007/bf00982109] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/1990] [Accepted: 07/16/1990] [Indexed: 11/28/2022]
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Witt MF, Pestka JJ. Uptake of the naturally occurring 3-alpha-hydroxy isomer of T-2 toxin by a murine B cell hybridoma. Food Chem Toxicol 1990; 28:21-8. [PMID: 2312012 DOI: 10.1016/0278-6915(90)90131-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The uptake of the naturally occurring 3-alpha-hydroxy isomer of T-2 toxin (alpha-T-2 toxin) was investigated in a murine B cell hybridoma as a model for trichothecene-lymphocyte interactions. alpha-[3H]T-2 toxin was prepared by oxidation of T-2 toxin and reduction with [3H]NaBH4 followed by normal phase and reverse phase high-performance liquid chromatography. Uptake of alpha-[3H]T-2 toxin by hybridoma cells was both time- and concentration-dependent. The antibiotic anisomycin inhibited uptake of alpha-[3H]T-2 toxin by hybridoma cells, which suggests ribosomal involvement in the uptake mechanism. Uptake of alpha-[3H]T-2 toxin was also inhibited by verrucarin A, roridin A and deoxynivalenol, and the inhibition followed a trichothecene structure-activity rank similar to that established for protein synthesis inhibition and in vivo toxicity. The characteristics of uptake of alpha-[3H]T-2 toxin by isolated splenocytes were qualitatively similar to those of the hybridoma but accumulation at equilibrium was less. Accumulation of alpha-[3H]T-2 toxin by erythrocytes, cells lacking ribosomes, did not increase with time and was not affected by the presence of unlabelled toxin. The results suggested that specific accumulation and uptake of alpha-[3H]T-2 toxin by the murine B cell hybridoma and spleen cells were highly consistent with a model based on intracellular binding of T-2 toxin to ribosomes.
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Affiliation(s)
- M F Witt
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224
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Abstract
The binding of radiolabeled T-2 to eukaryotic ribosomes was studied. The toxin bound to ribosomes in a time-, temperature- and concentration-dependent manner. The binding was saturable (0.3 nM), reversible at 37 degrees (half-time approximately 2.5 hr) and specific. The stoichiometry was one toxin molecule bound per ribosome. Binding of T-2 appeared to stablize the toxin recognition site to thermal degradation. A synthetically derived epimer of T-2 bound to the same ribosomal site as authentic T-2, but apparently with lower affinity. Two other trichothecene toxins tested blocked the binding of T-2 to ribosomes in a manner reflecting their protein synthesis inhibitory potencies. Anisomycin blocked the binding of T-2 to both isolated ribosomes and cells, whereas emetine blocked binding only to cells. Our data, together with that in the accompanying paper (Middlebrook JL and Leatherman DL, Biochem Pharmacol 38: 3093-3102, 1989), suggest that T-2 interaction with CHO cells is best viewed as a free, bidirectional movement of toxin across the plasma membrane and specific high-affinity binding to ribosomes.
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Affiliation(s)
- J L Middlebrook
- Department of Toxinology, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21701-5011
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17
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Abstract
The binding of radiolabeled T-2 toxin to a mammalian cell line derived from a Chinese hamster ovary (CHO) was studied. The toxin bound to, or was taken up by, cells in a time-, temperature- and concentration-dependent manner. The binding was saturable, of high affinity (Kd approximately 0.1 to 1 nM), reversible at 37 degrees (half-time approximately 2 hr), and specific. The kinetics of T-2-cell association and the rate of toxin-induced inhibition of protein synthesis closely paralleled one another. Likewise, the concentration-response for inhibition of protein synthesis and the toxin binding isotherm were similar. A synthetically derived epimer of T-2 bound less tightly to cells, but apparently to the same site as authentic T-2. The epimer was also less potent at inducing inhibition of protein synthesis. Two other trichothecene toxins, one more and one less toxic than T-2, blocked labeled T-2 binding to cells in a manner reflective of their protein synthesis inhibitory potencies. We conclude that the binding we defined is an accurate measure of the toxin responsible for inhibition of protein synthesis in CHO cells. The data also suggested that, at equilibrium, the interaction of T-2 with cells is not static, but is the sum of a continuous uptake and release process.
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Affiliation(s)
- J L Middlebrook
- Department of Toxinology, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21701-5011
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18
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Abstract
Relationships between structural features and biological effects of mycotoxins are reviewed. Structure-activity relationships are characterized at the molecular, subcellular, cellular, or supracellular level. Major chemical and physicochemical factors responsible for bioactivity of mycotoxins are stressed. A variety of chemical families of mycotoxins are then discussed from the point of view of structure-activity relationships. The structurally related families comprise small lactones, macrocyclic lactones, isocoumarin derivatives, aflatoxins and related compounds trichothecenes, anthraquinones, indole-derived tremorgens and selected amino acid-derived mycotoxins such as sporidesmins and cyclosporines. Biological effects of mycotoxins include acute and chronic toxicity, antimicrobial activity, mutagenicity and genotoxicity, carcinogenicity and biochemical modes of action.
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Affiliation(s)
- V Betina
- Department of Environmental Chemistry and Technology, Faculty of Chemistry, Slovak Polytechnical University, Bratislava
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Bunner DL, Morris ER. Alteration of multiple cell membrane functions in L-6 myoblasts by T-2 toxin: an important mechanism of action. Toxicol Appl Pharmacol 1988; 92:113-21. [PMID: 3341021 DOI: 10.1016/0041-008x(88)90233-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Recent studies suggest that T-2 toxin interacts with cell membranes and alters membrane function. This study was done to assess the effect of T-2 toxin on a broad range of cell membrane functions in L-6 myoblasts. The following parameters were assessed after exposure to T-2 toxin for 10 min: (1) the uptake of calcium, rubidium, and glucose; (2) the uptake of leucine and tyrosine and incorporation into protein; (3) the uptake of thymidine and incorporation into DNA; and (4) residual cellular lactate dehydrogenase (LDH) as a measure of cell membrane integrity. The effects of T-2 toxin on these parameters were: (1) The minimal effective concentration (MEC) of T-2 toxin that caused a reduction in the uptake of calcium and glucose was 4 pg/ml. The uptake of rubidium was increased at 0.4 pg/ml and then reduced at 4 pg/ml and higher concentrations. (2) The MEC for reduction of the uptake of leucine and tyrosine and their incorporation into protein was 4 pg/ml. (3) Thymidine uptake and incorporation into DNA showed a biphasic response with an increase at 0.4 pg/ml and a reduction at 4 pg for uptake and 40 pg/ml for incorporation. (4) Intracellular LDH was reduced at 4 ng/ml. (5) Calcium efflux was reduced after 1-, 5-, and 15-min exposures to T-2 toxin in a concentration of 40 ng/ml. All of the changes noted, including protein synthesis inhibition, were present to a significant degree within 10 min of exposure to T-2 toxin. This time interval is too short to attribute all of these effects directly to protein synthesis inhibition since most short-lived proteins have half-lives measured in hours. In conclusion, T-2 toxin appears to have multiple effects on cell membrane function at very low concentrations (0.4 pg/ml to 4 ng/ml), which are independent of protein synthesis inhibition. These likely include effects either direct or indirect on amino acid, nucleotide, and glucose transporters, as well as calcium and potassium (rubidium) channel activities.
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Affiliation(s)
- D L Bunner
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland 21701-5011
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20
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Abstract
We examined the effect of sodium fluoride on uptake of tritium-labeled T-2 toxin (molecules of toxin/cell) in Chinese hamster ovary (CHO) and African green monkey kidney (VERO) cells. Correlations were made to temperature (22 and 37 degrees C) and toxin concentration (0.001 and 0.01 microgram/ml) over time (0-180 min). As expected, toxin uptake increased in both cell types with increasing time and temperature. VERO cells exhibited significant (P less than 0.05) increases in the rate (i.e. slope) of toxin uptake under all parameters, while the rate of toxin uptake in both cell types was generally greater at 37 degrees C compared to 22 degrees C. The rate of equilibrium was affected by both temperature and sodium fluoride. At 37 degrees C toxin uptake plateaued by 30 min in the presence of sodium fluoride. At 22 degrees C the rate of toxin uptake was slower, with or without sodium fluoride present. Statistical analysis of individual time points along the curve demonstrated that sodium fluoride significantly increased cell-associated toxin at most time points. Analysis of the slopes of uptake curves from 0 to 20 min indicated significant (P less than 0.05) differences in the rates of T-2 uptake in both cell types and toxin doses in the presence of sodium fluoride. The increase in toxin uptake in the presence of sodium fluoride was not due to altered cell membrane permeability caused by sodium fluoride. This study demonstrates that sodium fluoride significantly increases cell-associated T-2 toxin and the rate of toxin uptake in two cultured cell lines.
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Affiliation(s)
- L R Trusal
- Pathology Division, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21701-5011
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Ehrlich KC, Daigle KW. Protein synthesis by mammalian cells treated with C-3-modified analogs of the 12,13-epoxytrichothecenes T-2 and T-2 tetraol. Appl Environ Microbiol 1985; 50:914-8. [PMID: 3866515 PMCID: PMC291768 DOI: 10.1128/aem.50.4.914-918.1985] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Modification at the C-3 position of the trichothecenes T-2 and T-2 tetraol affected their ability to inhibit protein synthesis in African green monkey kidney (Vero) and mouse erythroleukemia cells. Replacement of the 3-hydroxyl of T-2 with hydrogen caused a 24-fold decrease in activity, whereas acetylation resulted in a 500-to 1,000-fold decrease. Protection of the 3-hydroxyl with a tetrahydropyranyl moiety gave an analog that was 37-fold more inhibitory to Vero than to mouse erythroleukemia cells; with the other analogs a similar effect on protein synthesis was found for both types of cells. The analogs obtained after alkaline hydrolysis were much less potent than the parent trichothecenes. The 3-tetrahydropyranyl-modified analog was equivalent in potency to T-2 tetraol, while the deoxygenated species was at least threefold less potent. All T-2 analogs caused some degree of polysome "runoff," thereby demonstrating that these species inhibit protein synthesis at the chain initiation stage when added at their 50% infective dose concentrations or lower. From these results, we suggest that the 3-hydroxyl moiety is essential for T-2 to exhibit such high activity on eucaryotic cell protein synthesis and that modification at the C-3 position decreases but does not eliminate this activity.
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Trusal LR. Morphological changes in CHO and VERO cells treated with T-2 mycotoxin. Correlation with inhibition of protein synthesis. Cell Biochem Funct 1985; 3:205-16. [PMID: 3836022 DOI: 10.1002/cbf.290030308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Exposure of Chinese hamster ovary and African green monkey kidney cells to T-2 mycotoxin resulted in several morphological changes which were related to inhibition of protein synthesis, the basic in vitro mechanism of action of the toxin. These changes, which occurred in both cell types, included disassociation of polysomes and mitochondrial cristae alterations. In addition, CHO cells displayed membrane bleb formations similar to those found in CHO cells after exposure to established inhibitors of protein synthesis, puromycin and anisomycin. Blebs could be either a result of protein synthesis inhibition or a non-specific early pathological response. Bleb formations were not observed in VERO cells under any experimental condition.
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Thompson WL, Wannemacher RW. Detection and quantitation of T-2 mycotoxin with a simplified protein synthesis inhibition assay. Appl Environ Microbiol 1984; 48:1176-80. [PMID: 6517584 PMCID: PMC241705 DOI: 10.1128/aem.48.6.1176-1180.1984] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We describe a simple, rapid, and sensitive bioassay for the detection and quantitation of T-2 mycotoxin by using a protein synthesis assay in cultured cells. Increased sensitivity of the cells to the mycotoxin occurred with time up to ca. 60-min. Time and dose response curves show that an average of 10 to 20 ng of T-2 per ml was sufficient to cause 50% inhibition of protein synthesis in tissue culture cells. A wide range of tissue culture cells with varied type, tissue, and species sources and growth characteristics were tested by this system. All showed approximately the same sensitivity to the mycotoxin. A slight modification of the procedure was used for suspended cultures of mitogen-stimulated lymphocytes, which also showed an equal degree of sensitivity to the mycotoxin. By simply changing the labeled precursor, the inhibition of RNA, DNA, and protein synthesis by T-2 mycotoxin can be compared. Although T-2 mycotoxin had little effect on RNA synthesis, DNA and protein synthesis were equally inhibited. Because of its sensitivity and its capacity to quickly assay a large number of samples, this technique has been a valuable tool in screening samples for the presence of active toxin and has been used to help establish laboratory safety standards for the inactivation of T-2 mycotoxin by chemical agents. It is presently being used in studies of mycotoxin mechanism of action and approaches toward in vivo neutralization of the toxic effects of mycotoxins.
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Mann DD, Buening GM, Osweiler GD, Hook BS. Effect of subclinical levels of T-2 toxin on the bovine cellular immune system. CANADIAN JOURNAL OF COMPARATIVE MEDICINE : REVUE CANADIENNE DE MEDECINE COMPAREE 1984; 48:308-12. [PMID: 6332662 PMCID: PMC1236068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effect of subclinical levels of mycotoxin T-2 on the cells of the bovine immune system was investigated in two in vivo experiments. In experiment 1, five calves were orally dosed with 0.3 mg/kg/day of T-2 toxin for 56 days and five calves were pair fed controls. The neutrophil function as measured by nitroblue tetrazolium reduction was reduced in the mycotoxin treated calves. The cutaneous reaction to intradermally injected phytohemagglutinin was reduced in the T-2 toxin treated calves. B-cell (SIg+) numbers increased slightly, but T-cell (PNA+) numbers were not affected during the experimental period. In the second experiment, six calves were given 0.5 mg/kg/day T-2 toxin orally for 28 days and six calves were pair fed controls. B-cell numbers and the response of a B-cell enriched fraction to phytohemagglutinin increased after toxin administration. T-cell numbers and the response of a T-cell enriched fraction and the whole mononuclear cell population to phytohemagglutinin was reduced only on day 19 posttoxin administration. The in vitro (T-2 toxin) exposure of the mononuclear cell population, B-cell enriched, or T-cell enriched fraction reduced their lymphoblastic response to mitogens. A 50% reduction was induced by as little as 1.4 ng/mL of T-2 toxin.
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25
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Liou YF, Hall IH, Lee KH. Antitumor agents LIV: The effects of daphnoretin on in vitro protein synthesis of Ehrlich ascites carcinoma cells and other tissues. J Pharm Sci 1982; 71:745-9. [PMID: 7120056 DOI: 10.1002/jps.2600710707] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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26
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Willingham W, Stafford EA, Reynolds SH, Chaney SG, Lee KH, Okano M, Hall IH. Mechanism of eukaryotic protein synthesis inhibition by brusatol. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 654:169-74. [PMID: 7284376 DOI: 10.1016/0005-2787(81)90168-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The mechanism by which brusatol inhibits protein synthesis in rabbit reticulocytes has been investigated. When added to reticulocyte lysates, brusatol inhibits endogenous protein synthesis only after a lag of 2-4 min at 30 degrees C. During this period 80 S ribosomes accumulate. Brusatol is equally effective in inhibiting endogenous protein synthesis in lysates and poly(U)-directed polyphenylalanine synthesis with runoff ribosomes. In fractionated reticulocyte systems, brusatol does not inhibit formation of the ternary, 40 S, and 80 S initiation complexes, but does inhibit the reaction of puromycin with initiation complexes containing [35S]Met-tRNAf. These data suggest that brusatol inhibits the peptidyl transferase elongation reaction of protein synthesis, but can do so only after one round of protein synthesis has been completed. Thus, the mechanism of action of brusatol in the rabbit reticulocyte system is very similar to the effects previously reported for bruceantin in a yeast system.
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27
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Munsch N, Müller WE. Effects of T2 toxin on DNA polymerases and terminal deoxynucleotidyl transferase of Molt4 and Nu8 cell lines. IMMUNOPHARMACOLOGY 1980; 2:313-8. [PMID: 6936393 DOI: 10.1016/0162-3109(80)90015-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
T2-toxin effects on [3H]TdR incorporation, polymerase alpha and beta terminal deoxynucleotidyl transferase, and thymidine kinase activities of two thymus derived cell lines, Molt4 and Nu8, have been measured. T2-toxin, which specifically affects the immune system, inhibits [3H]TdR incorporation at doses of 0.1-10ng/ml. With regard to enzymatic activities, at doses of T2 toxin of 0.1-1 ng/ml a transient enzymatic increase is observed. In contrast, for T2-toxin concentrations greater than 1 ng/ml, alpha polymerase and TdT activities of Nu8 cells are also inhibited. These inhibitions account for the already described effects of T2 toxin and, in particular, the impaired DNA and protein synthesis.
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28
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Hobden AN, Cundliffe E. Ribosomal resistance to the 12,13-epoxytrichothecene antibiotics in the producing organism Myrothecium verrucaria. Biochem J 1980; 190:765-70. [PMID: 7008785 PMCID: PMC1162157 DOI: 10.1042/bj1900765] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
An extract of Myrothecium verrucaria, a fungus which produces a range of 12,13-epoxytrichothecene toxins, was found to be resistant to T-2 toxin, one of its products. The epoxytrichothecenes are inhibitors of eukaryotic protein synthesis and normally bind to the 60S ribosomal subunit so as to inhibit peptidyltransferase activity. Ribosomes from M. verrucaria contain 60S subunits which are not subject to inhibition by T-2 toxin and are also resistant to certain other drugs such as anisomycin and homoharringtonine, but not sparsomycin or cycloheximide.
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29
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Baez A, Vazquez D. Binding of [3H]narciclasine to eukaryotic ribosomes. A study on a structure-activity relationship. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 518:95-103. [PMID: 343817 DOI: 10.1016/0005-2787(78)90119-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
[3H]Narciclasine is a specific inhibitor of peptide bond formation on eukaryotic ribosomes and binds to 60-S ribosomal subunits. Binding of [3H]-narciclasine to yeast ribosomes is inhibited by many other inhibitors of peptide bond formation including anisomycin, several sequiterpene antibiotics (trichodermin, trichothecin, fusarenon X and verrucarin A) several Cephalotaxus alkaloids (harringtonine, homoharringtonine and isoharringtonine), several Amaryllidaceae alkaloids (pretazettine, haemanthamine, lycorine, pseudolycorine and dihydrolycorine) and the narciclasine derivatives trans-dihydronarciclasine, trans-dihydronarciclasine acetonide and isonarciclasine. Binding is also inhibited, although to a very small extent, by methylnarciclasine and cisdihydronarciclasine. In contrast, no inhibition of [3H]narciclasine binding was observed in the presence of certain other inhibitors of peptide bond formation including blasticidin S, gougerotin, sparsomycin and puromycin.
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30
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Fresno M, Gonzales A, Vazquez D, Jiménez A. Bruceantin, a novel inhibitor of peptide bond formation. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 518:104-12. [PMID: 343816 DOI: 10.1016/0005-2787(78)90120-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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31
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Carter CJ, Cannon M. Inhibition of eukaryotic ribosomal function by the sesquiterpenoid antibiotic fusarenon-X. EUROPEAN JOURNAL OF BIOCHEMISTRY 1978; 84:103-11. [PMID: 648514 DOI: 10.1111/j.1432-1033.1978.tb12146.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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32
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Carter CJ, Cannon M. Structural requirements for the inhibitory action of 12,13-epoxytrichothecenes on protein synthesis in eukaryotes. Biochem J 1977; 166:399-409. [PMID: 597234 PMCID: PMC1165022 DOI: 10.1042/bj1660399] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
1. The inhibitory actions of ten trichothecene antibiotics were investigated, in reticulocyte cell-free systems synthesizing protein in vitro, by studying polyribosome profiles and kinetics of amino acid incorporation in the presence or absence of the drugs. 2. The modes of action observed were critically dependent on the drug concentrations used, but the antibiotics tested could be divided into four distinct groups, each exerting a characteristic inhibitory response. 3. The inhibitory action observed in every case was controlled by the chemical structure of the individual trichothecene and in particular was closely related to the nature of the substituent groups present on C-3, C-4, C-8 and C-15 of the molecule.
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Fresno M, Jiménez A, Vázquez D. Inhibition of translation in eukaryotic systems by harringtonine. EUROPEAN JOURNAL OF BIOCHEMISTRY 1977; 72:323-30. [PMID: 319998 DOI: 10.1111/j.1432-1033.1977.tb11256.x] [Citation(s) in RCA: 207] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The Cephalotaxus alkaloids harringtonine, homoharringtonine and isoharringtonine inhibit protein synthesis in eukaryotic cells. The alkaloids do not inhibit, in model systems, any of the steps of the initiation process but block poly(U)-directed polyphenylalanine synthesis as well as peptide bond formation in the fragment reaction assay, the sparsomycin-induced binding of (C)U-A-C-C-A-[3H]Leu-Ac, and the enzymic and the non-enzymic binding of Phe-tRNA to ribosomes. These results suggest that the Cephalotaxus alkaloids inhibit the elongation phase of translation by preventing substrate binding to the acceptor site on the 60-S ribosome subunit and therefore block aminoacyl-tRNA binding and peptide bond formation. However, the Cephalotaxus alkaloids do not inhibit polypeptide synthesis and peptidyl[3H]puromycin formation in polysomes. Furthermore, these alkaloids strongly inhibit [14C]trichlodermin binding to free ribosomes but hardly affect the interaction of the antibiotic with yeast polysomot interact with polysomes and therefore only inhibit cycles of elongation. This explains the polysome run off that has been observed by some workers in the presence of harringtonine.
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