1
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Targeting the Inside of Cells with Biologicals: Toxin Routes in a Therapeutic Context. BioDrugs 2023; 37:181-203. [PMID: 36729328 PMCID: PMC9893211 DOI: 10.1007/s40259-023-00580-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2023] [Indexed: 02/03/2023]
Abstract
Numerous toxins translocate to the cytosol in order to fulfil their function. This demonstrates the existence of routes for proteins from the extracellular space to the cytosol. Understanding these routes is relevant to multiple aspects related to therapeutic applications. These include the development of anti-toxin treatments, the potential use of toxins as shuttles for delivering macromolecular cargo to the cytosol or the use of drugs based on toxins. Compared with other strategies for delivery, such as chemicals as carriers for macromolecular delivery or physical methods like electroporation, toxin routes present paths into the cell that potentially cause less damage and can be specifically targeted. The efficiency of delivery via toxin routes is limited. However, low-delivery efficiencies can be entirely sufficient, if delivered cargoes possess an amplification effect or if very few molecules are sufficient for inducing the desired effects. This is known for example from RNA-based vaccines that have been developed during the coronavirus disease 2019 pandemic as well as for other approved RNA-based drugs, which elicited the desired effect despite their typically low delivery efficiencies. The different mechanisms by which toxins enter cells may have implications for their technological utility. We review the mechanistic principles of the translocation pathway of toxins from the extracellular space to the cytosol, the delivery efficiencies, and therapeutic strategies or applications that exploit toxin routes for intracellular delivery.
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2
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Ernst K. Requirement of Peptidyl-Prolyl Cis/Trans isomerases and chaperones for cellular uptake of bacterial AB-type toxins. Front Cell Infect Microbiol 2022; 12:938015. [PMID: 35992160 PMCID: PMC9387773 DOI: 10.3389/fcimb.2022.938015] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/15/2022] [Indexed: 11/30/2022] Open
Abstract
Bacterial AB-type toxins are proteins released by the producing bacteria and are the causative agents for several severe diseases including cholera, whooping cough, diphtheria or enteric diseases. Their unique AB-type structure enables their uptake into mammalian cells via sophisticated mechanisms exploiting cellular uptake and transport pathways. The binding/translocation B-subunit facilitates binding of the toxin to a specific receptor on the cell surface. This is followed by receptor-mediated endocytosis. Then the enzymatically active A-subunit either escapes from endosomes in a pH-dependent manner or the toxin is further transported through the Golgi to the endoplasmic reticulum from where the A-subunit translocates into the cytosol. In the cytosol, the A-subunits enzymatically modify a specific substrate which leads to cellular reactions resulting in clinical symptoms that can be life-threatening. Both intracellular uptake routes require the A-subunit to unfold to either fit through a pore formed by the B-subunit into the endosomal membrane or to be recognized by the ER-associated degradation pathway. This led to the hypothesis that folding helper enzymes such as chaperones and peptidyl-prolyl cis/trans isomerases are required to assist the translocation of the A-subunit into the cytosol and/or facilitate their refolding into an enzymatically active conformation. This review article gives an overview about the role of heat shock proteins Hsp90 and Hsp70 as well as of peptidyl-prolyl cis/trans isomerases of the cyclophilin and FK506 binding protein families during uptake of bacterial AB-type toxins with a focus on clostridial binary toxins Clostridium botulinum C2 toxin, Clostridium perfringens iota toxin, Clostridioides difficile CDT toxin, as well as diphtheria toxin, pertussis toxin and cholera toxin.
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3
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Brücksken KA, Loreto Palacio P, Hanschmann EM. Thiol Modifications in the Extracellular Space-Key Proteins in Inflammation and Viral Infection. Front Immunol 2022; 13:932525. [PMID: 35833136 PMCID: PMC9271835 DOI: 10.3389/fimmu.2022.932525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Posttranslational modifications (PTMs) allow to control molecular and cellular functions in response to specific signals and changes in the microenvironment of cells. They regulate structure, localization, stability, and function of proteins in a spatial and temporal manner. Among them, specific thiol modifications of cysteine (Cys) residues facilitate rapid signal transduction. In fact, Cys is unique because it contains the highly reactive thiol group that can undergo different reversible and irreversible modifications. Upon inflammation and changes in the cellular microenvironment, many extracellular soluble and membrane proteins undergo thiol modifications, particularly dithiol-disulfide exchange, S-glutathionylation, and S-nitrosylation. Among others, these thiol switches are essential for inflammatory signaling, regulation of gene expression, cytokine release, immunoglobulin function and isoform variation, and antigen presentation. Interestingly, also the redox state of bacterial and viral proteins depends on host cell-mediated redox reactions that are critical for invasion and infection. Here, we highlight mechanistic thiol switches in inflammatory pathways and infections including cholera, diphtheria, hepatitis, human immunodeficiency virus (HIV), influenza, and coronavirus disease 2019 (COVID-19).
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Affiliation(s)
| | | | - Eva-Maria Hanschmann
- Department of Neurology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
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4
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Pereira C, Rodrigues IS, Pereira LMG, Lisboa J, Pinto RD, Araújo L, Oliveira P, Benz R, Dos Santos NMS, do Vale A. Role of AIP56 disulphide bond and its reduction by cytosolic redox systems for efficient intoxication. Cell Microbiol 2019; 22:e13109. [PMID: 31454143 DOI: 10.1111/cmi.13109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/08/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022]
Abstract
Apoptosis-inducing protein of 56 kDa (AIP56) is a major virulence factor of Photobacterium damselae subsp. piscicida, a gram-negative pathogen that infects warm water fish species worldwide and causes serious economic losses in aquacultures. AIP56 is a single-chain AB toxin composed by two domains connected by an unstructured linker peptide flanked by two cysteine residues that form a disulphide bond. The A domain comprises a zinc-metalloprotease moiety that cleaves the NF-kB p65, and the B domain is involved in binding and internalisation of the toxin into susceptible cells. Previous experiments suggested that disruption of AIP56 disulphide bond partially compromised toxicity, but conclusive evidences supporting the importance of that bond in intoxication were lacking. Here, we show that although the disulphide bond of AIP56 is dispensable for receptor recognition, endocytosis, and membrane interaction, it needs to be intact for efficient translocation of the toxin into the cytosol. We also show that the host cell thioredoxin reductase-thioredoxin system is involved in AIP56 intoxication by reducing the disulphide bond of the toxin at the cytosol. The present study contributes to a better understanding of the molecular mechanisms operating during AIP56 intoxication and reveals common features shared with other AB toxins.
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Affiliation(s)
- Cassilda Pereira
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Inês S Rodrigues
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Liliana M G Pereira
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Johnny Lisboa
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Rute D Pinto
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Leonor Araújo
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Pedro Oliveira
- EPIUnit, ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Roland Benz
- Department of Life Sciences and Chemistry, Jacobs University, Bremen, Germany
| | - Nuno M S Dos Santos
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Ana do Vale
- Fish Immunology and Vaccinology Group, IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
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5
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Dan K, Veetil AT, Chakraborty K, Krishnan Y. DNA nanodevices map enzymatic activity in organelles. NATURE NANOTECHNOLOGY 2019; 14:252-259. [PMID: 30742135 PMCID: PMC6859052 DOI: 10.1038/s41565-019-0365-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/18/2018] [Indexed: 05/18/2023]
Abstract
Cellular reporters of enzyme activity are based on either fluorescent proteins or small molecules. Such reporters provide information corresponding to wherever inside cells the enzyme is maximally active and preclude minor populations present in subcellular compartments. Here we describe a chemical imaging strategy to selectively interrogate minor, subcellular pools of enzymatic activity. This new technology confines the detection chemistry to a designated organelle, enabling imaging of enzymatic cleavage exclusively within the organelle. We have thus quantitatively mapped disulfide reduction exclusively in endosomes in Caenorhabditis elegans and identified that exchange is mediated by minor populations of the enzymes PDI-3 and TRX-1 resident in endosomes. Impeding intra-endosomal disulfide reduction by knocking down TRX-1 protects nematodes from infection by Corynebacterium diphtheriae, revealing the importance of this minor pool of endosomal TRX-1. TRX-1 also mediates endosomal disulfide reduction in human cells. A range of enzymatic cleavage reactions in organelles are amenable to analysis by this new reporter strategy.
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Affiliation(s)
- Krishna Dan
- Department of Chemistry, University of Chicago, Chicago, IL, USA
- Grossman Institute of Neuroscience, Quantitative Biology and Human Behaviour, University of Chicago, Chicago, IL, USA
| | - Aneesh T Veetil
- Department of Chemistry, University of Chicago, Chicago, IL, USA
- Grossman Institute of Neuroscience, Quantitative Biology and Human Behaviour, University of Chicago, Chicago, IL, USA
| | - Kasturi Chakraborty
- Department of Chemistry, University of Chicago, Chicago, IL, USA
- Grossman Institute of Neuroscience, Quantitative Biology and Human Behaviour, University of Chicago, Chicago, IL, USA
| | - Yamuna Krishnan
- Department of Chemistry, University of Chicago, Chicago, IL, USA.
- Grossman Institute of Neuroscience, Quantitative Biology and Human Behaviour, University of Chicago, Chicago, IL, USA.
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6
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Schuster M, Schnell L, Feigl P, Birkhofer C, Mohr K, Roeder M, Carle S, Langer S, Tippel F, Buchner J, Fischer G, Hausch F, Frick M, Schwan C, Aktories K, Schiene-Fischer C, Barth H. The Hsp90 machinery facilitates the transport of diphtheria toxin into human cells. Sci Rep 2017; 7:613. [PMID: 28377614 PMCID: PMC5429619 DOI: 10.1038/s41598-017-00780-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 03/13/2017] [Indexed: 01/12/2023] Open
Abstract
Diphtheria toxin kills human cells because it delivers its enzyme domain DTA into their cytosol where it inhibits protein synthesis. After receptor-mediated uptake of the toxin, DTA translocates from acidic endosomes into the cytosol, which might be assisted by host cell factors. Here we investigated the role of Hsp90 and its co-chaperones during the uptake of native diphtheria toxin into human cells and identified the components of the Hsp90 machinery including Hsp90, Hsp70, Cyp40 and the FK506 binding proteins FKBP51 and FKBP52 as DTA binding partners. Moreover, pharmacological inhibition of the chaperone activity of Hsp90 and Hsp70 and of the peptidyl-prolyl cis/trans isomerase (PPIase) activity of Cyps and FKBPs protected cells from intoxication with diphtheria toxin and inhibited the pH-dependent trans-membrane transport of DTA into the cytosol. In conclusion, these host cell factors facilitate toxin uptake into human cells, which might lead to development of novel therapeutic strategies against diphtheria.
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Affiliation(s)
- Manuel Schuster
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Leonie Schnell
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Peter Feigl
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Carina Birkhofer
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Katharina Mohr
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Maurice Roeder
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Stefan Carle
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Simon Langer
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
| | - Franziska Tippel
- Munich Center for Integrated Protein Science and Department Chemistry, Technical University of Munich, Munich, Germany
| | - Johannes Buchner
- Munich Center for Integrated Protein Science and Department Chemistry, Technical University of Munich, Munich, Germany
| | - Gunter Fischer
- Max Planck Research Unit for Enzymology of Protein Folding Halle, Halle, Saale, Germany
| | - Felix Hausch
- Institute for Organic Chemistry and Biochemistry, Technical University Darmstadt, Darmstadt, Germany.,Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Manfred Frick
- Institute of General Physiology, University of Ulm, Ulm, Germany
| | - Carsten Schwan
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79104, Freiburg, Germany
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, 79104, Freiburg, Germany
| | - Cordelia Schiene-Fischer
- Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Saale, Germany
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany.
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7
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Legler PM, Compton JR, Hale ML, Anderson GP, Olson MA, Millard CB, Goldman ER. Stability of isolated antibody-antigen complexes as a predictive tool for selecting toxin neutralizing antibodies. MAbs 2016; 9:43-57. [PMID: 27660893 PMCID: PMC5240650 DOI: 10.1080/19420862.2016.1236882] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ricin is an A-B ribosome inactivating protein (RIP) toxin composed of an A-chain subunit (RTA) that contains a catalytic N-glycosidase and a B-chain (RTB) lectin domain that binds cell surface glycans. Ricin exploits retrograde transport to enter into the Golgi and the endoplasmic reticulum, and then dislocates into the cytoplasm where it can reach its substrate, the rRNA. A subset of isolated antibodies (Abs) raised against the RTA subunit protect against ricin intoxication, and RTA-based vaccine immunogens have been shown to provide long-lasting protective immunity against the holotoxin. Anti-RTA Abs are unlikely to cross a membrane and reach the cytoplasm to inhibit the enzymatic activity of the A-chain. Moreover, there is not a strict correlation between the apparent binding affinity (Ka) of anti-RTA Abs and their ability to successfully neutralize ricin toxicity. Some anti-RTA antibodies are toxin-neutralizing, whereas others are not. We hypothesize that neutralizing anti-RTA Abs may interfere selectively with conformational change(s) or partial unfolding required for toxin internalization. To test this hypothesis, we measured the melting temperatures (Tm) of neutralizing single-domain Ab (sdAb)-antigen (Ag) complexes relative to the Tm of the free antigen (Tm-shift = Tmcomplex – TmAg), and observed increases in the Tmcomplex of 9–20 degrees. In contrast, non-neutralizing sdAb-Ag complexes shifted the TmComplex by only 6–7 degrees. A strong linear correlation (r2 = 0.992) was observed between the magnitude of the Tm-shift and the viability of living cells treated with the sdAb and ricin holotoxin. The Tm-shift of the sdAb-Ag complex provided a quantitative biophysical parameter that could be used to predict and rank-order the toxin-neutralizing activities of Abs. We determined the first structure of an sdAb-RTA1-33/44-198 complex, and examined other sdAb-RTA complexes. We found that neutralizing sdAb bound to regions involved in the early stages of unfolding. These Abs likely interfere with steps preceding or following endocytosis that require conformational changes. This method may have utility for the characterization or rapid screening of other Ab that act to prevent conformational changes or unfolding as part of their mechanism of action.
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Affiliation(s)
| | | | - Martha L Hale
- c US Army Medical Research Institute of Infectious Diseases , Frederick , MD , USA
| | | | - Mark A Olson
- c US Army Medical Research Institute of Infectious Diseases , Frederick , MD , USA
| | - Charles B Millard
- c US Army Medical Research Institute of Infectious Diseases , Frederick , MD , USA
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8
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Liu X, Hu D, Jiang Z, Zhuang J, Xu Y, Guo X, Thayumanavan S. Multi-Stimuli-Responsive Amphiphilic Assemblies through Simple Postpolymerization Modifications. Macromolecules 2016; 49:6186-6192. [PMID: 29353939 DOI: 10.1021/acs.macromol.6b01397] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A strategy to construct different stimuli responsive polymers from post polymerization modifications of a single polymer scaffold via thiol-disulfide exchange has been developed. Here, we report on a random copolymer that enables the design and syntheses of a series of dual or multi-stimuli responsive nanoassemblies using a simple post-polymerization modification step. The reactive functional group involves a side chain monopyridyl disulfide unit, which rapidly and quantitatively reacts with various thiols under mild conditions. Independent and concurrent incorporation of physical, chemical or biologically responsive properties have been demonstrated. We envision that this strategy may open up opportunities to simplify the synthesis of multi-functional polymers with broad implications in a variety of biological applications.
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Affiliation(s)
- Xiaochi Liu
- State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.,Department of Chemistry, University of Massachusetts, Ameherst, Massachusetts 01003, United States
| | - Ding Hu
- Department of Chemistry, University of Massachusetts, Ameherst, Massachusetts 01003, United States
| | - Ziwen Jiang
- Department of Chemistry, University of Massachusetts, Ameherst, Massachusetts 01003, United States
| | - Jiaming Zhuang
- Department of Chemistry, University of Massachusetts, Ameherst, Massachusetts 01003, United States
| | - Yisheng Xu
- State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xuhong Guo
- State-Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - S Thayumanavan
- Department of Chemistry, University of Massachusetts, Ameherst, Massachusetts 01003, United States
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9
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Schnell L, Mittler AK, Mattarei A, Azarnia Tehran D, Montecucco C, Barth H. Semicarbazone EGA Inhibits Uptake of Diphtheria Toxin into Human Cells and Protects Cells from Intoxication. Toxins (Basel) 2016; 8:E221. [PMID: 27428999 PMCID: PMC4963853 DOI: 10.3390/toxins8070221] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/25/2016] [Accepted: 07/07/2016] [Indexed: 01/29/2023] Open
Abstract
Diphtheria toxin is a single-chain protein toxin that invades human cells by receptor-mediated endocytosis. In acidic endosomes, its translocation domain inserts into endosomal membranes and facilitates the transport of the catalytic domain (DTA) from endosomal lumen into the host cell cytosol. Here, DTA ADP-ribosylates elongation factor 2 inhibits protein synthesis and leads to cell death. The compound 4-bromobenzaldehyde N-(2,6-dimethylphenyl)semicarbazone (EGA) has been previously shown to protect cells from various bacterial protein toxins which deliver their enzymatic subunits from acidic endosomes to the cytosol, including Bacillus anthracis lethal toxin and the binary clostridial actin ADP-ribosylating toxins C2, iota and Clostridium difficile binary toxin (CDT). Here, we demonstrate that EGA also protects human cells from diphtheria toxin by inhibiting the pH-dependent translocation of DTA across cell membranes. The results suggest that EGA might serve for treatment and/or prevention of the severe disease diphtheria.
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Affiliation(s)
- Leonie Schnell
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Ann-Katrin Mittler
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Andrea Mattarei
- Department of Chemical Sciences, University of Padova, 35121 Padova, Italy.
| | | | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy.
| | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
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10
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Host Cell Chaperones Hsp70/Hsp90 and Peptidyl-Prolyl Cis/Trans Isomerases Are Required for the Membrane Translocation of Bacterial ADP-Ribosylating Toxins. Curr Top Microbiol Immunol 2016; 406:163-198. [PMID: 27197646 DOI: 10.1007/82_2016_14] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacterial ADP-ribosylating toxins are the causative agents for several severe human and animal diseases such as diphtheria, cholera, or enteric diseases. They display an AB-type structure: The enzymatically active A-domain attaches to the binding/translocation B-domain which then binds to a receptor on the cell surface. After receptor-mediated endocytosis, the B-domain facilitates the membrane translocation of the unfolded A-domain into the host cell cytosol. Here, the A-domain transfers an ADP-ribose moiety onto its specific substrate which leads to characteristic cellular effects and thus to severe clinical symptoms. Since the A-domain has to reach the cytosol to achieve a cytotoxic effect, the membrane translocation represents a crucial step during toxin uptake. Host cell chaperones including Hsp90 and protein-folding helper enzymes of the peptidyl-prolyl cis/trans isomerase (PPIase) type facilitate this membrane translocation of the unfolded A-domain for ADP-ribosylating toxins but not for toxins with a different enzyme activity. This review summarizes the uptake mechanisms of the ADP-ribosylating clostridial binary toxins, diphtheria toxin (DT) and cholera toxin (CT), with a special focus on the interaction of these toxins with the chaperones Hsp90 and Hsp70 and PPIases of the cyclophilin and FK506-binding protein families during the membrane translocation of their ADP-ribosyltransferase domains into the host cell cytosol. Moreover, the medical implications of host cell chaperones and PPIases as new drug targets for the development of novel therapeutic strategies against diseases caused by bacterial ADP-ribosylating toxins are discussed.
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11
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Schnell L, Dmochewitz-Kück L, Feigl P, Montecucco C, Barth H. Thioredoxin reductase inhibitor auranofin prevents membrane transport of diphtheria toxin into the cytosol and protects human cells from intoxication. Toxicon 2015; 116:23-8. [PMID: 25911959 DOI: 10.1016/j.toxicon.2015.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 11/16/2022]
Abstract
During cellular uptake, diphtheria toxin delivers its catalytic domain DTA from acidified endosomes into the cytosol, which requires reduction of the disulfide linking DTA to the transport domain. In vitro, thioredoxin reduces this disulfide and thioredoxin reductase (TrxR) is part of a cytosolic complex facilitating DTA-translocation. We found that the TrxR-specific inhibitor auranofin prevented DTA delivery into the cytosol and intoxication of HeLa cells with diphtheria toxin, offering perspectives for novel pharmacological strategies against diphtheria.
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Affiliation(s)
- Leonie Schnell
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Germany
| | | | - Peter Feigl
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Germany
| | | | - Holger Barth
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Germany.
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12
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Jiang Y, Liu G, Wang X, Hu J, Zhang G, Liu S. Cytosol-Specific Fluorogenic Reactions for Visualizing Intracellular Disintegration of Responsive Polymeric Nanocarriers and Triggered Drug Release. Macromolecules 2015. [DOI: 10.1021/ma502389w] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Yanyan Jiang
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National
Laboratory for Physical Sciences at the Microscale, Collaborative
Innovation Center of Chemistry for Energy Materials, Department of
Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guhuan Liu
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National
Laboratory for Physical Sciences at the Microscale, Collaborative
Innovation Center of Chemistry for Energy Materials, Department of
Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaorui Wang
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National
Laboratory for Physical Sciences at the Microscale, Collaborative
Innovation Center of Chemistry for Energy Materials, Department of
Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jinming Hu
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National
Laboratory for Physical Sciences at the Microscale, Collaborative
Innovation Center of Chemistry for Energy Materials, Department of
Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guoying Zhang
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National
Laboratory for Physical Sciences at the Microscale, Collaborative
Innovation Center of Chemistry for Energy Materials, Department of
Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shiyong Liu
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National
Laboratory for Physical Sciences at the Microscale, Collaborative
Innovation Center of Chemistry for Energy Materials, Department of
Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
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13
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Ryu JH, Chacko RT, Jiwpanich S, Bickerton S, Babu RP, Thayumanavan S. Self-Cross-Linked Polymer Nanogels: A Versatile Nanoscopic Drug Delivery Platform. J Am Chem Soc 2010; 132:17227-35. [DOI: 10.1021/ja1069932] [Citation(s) in RCA: 449] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ja-Hyoung Ryu
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Reuben T. Chacko
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Siriporn Jiwpanich
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Sean Bickerton
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - R. Prakash Babu
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - S. Thayumanavan
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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14
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Kitadokoro K, Kamitani S, Miyazawa M, Hanajima-Ozawa M, Fukui A, Miyake M, Horiguchi Y. Crystal structures reveal a thiol protease-like catalytic triad in the C-terminal region of Pasteurella multocida toxin. Proc Natl Acad Sci U S A 2007; 104:5139-44. [PMID: 17360394 PMCID: PMC1829276 DOI: 10.1073/pnas.0608197104] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pasteurella multocida toxin (PMT), one of the virulence factors produced by the bacteria, exerts its toxicity by up-regulating various signaling cascades downstream of the heterotrimeric GTPases Gq and G12/13 in an unknown fashion. Here, we present the crystal structure of the C-terminal region (residues 575-1,285) of PMT, which carries an intracellularly active moiety. The overall structure of C-terminal region of PMT displays a Trojan horse-like shape, composed of three domains with a "feet"-,"body"-, and "head"-type arrangement, which were designated C1, C2, and C3 from the N to the C terminus, respectively. The C1 domain, showing marked similarity in steric structure to the N-terminal domain of Clostridium difficile toxin B, was found to lead the toxin molecule to the plasma membrane. The C3 domain possesses the Cys-His-Asp catalytic triad that is organized only when the Cys is released from a disulfide bond. The steric alignment of the triad corresponded well to that of papain or other enzymes carrying Cys-His-Asp. PMT toxicities on target cells were completely abrogated when one of the amino acids constituting the triad was mutated. Our results indicate that PMT is an enzyme toxin carrying the cysteine protease-like catalytic triad dependent on the redox state and functions on the cytoplasmic face of the plasma membrane of target cells.
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Affiliation(s)
- Kengo Kitadokoro
- *Research Center for Low Temperature and Materials Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan; and
| | - Shigeki Kamitani
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Masayuki Miyazawa
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Miyuki Hanajima-Ozawa
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Aya Fukui
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Masami Miyake
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
| | - Yasuhiko Horiguchi
- Department of Molecular Bacteriology, Research Institute for Microbial Diseases, Osaka University, Yamada-oka 3-1, Suita, Osaka 565-0871, Japan
- To whom correspondence should be sent. E-mail:
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15
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Ratts R, Zeng H, Berg EA, Blue C, McComb ME, Costello CE, vanderSpek JC, Murphy JR. The cytosolic entry of diphtheria toxin catalytic domain requires a host cell cytosolic translocation factor complex. J Cell Biol 2003; 160:1139-50. [PMID: 12668662 PMCID: PMC2172777 DOI: 10.1083/jcb.200210028] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In vitro delivery of the diphtheria toxin catalytic (C) domain from the lumen of purified early endosomes to the external milieu requires the addition of both ATP and a cytosolic translocation factor (CTF) complex. Using the translocation of C-domain ADP-ribosyltransferase activity across the endosomal membrane as an assay, the CTF complex activity was 650-800-fold purified from human T cell and yeast extracts, respectively. The chaperonin heat shock protein (Hsp) 90 and thioredoxin reductase were identified by mass spectrometry sequencing in CTF complexes purified from both human T cell and yeast. Further analysis of the role played by these two proteins with specific inhibitors, both in the in vitro translocation assay and in intact cell toxicity assays, has demonstrated their essential role in the productive delivery of the C-domain from the lumen of early endosomes to the external milieu. These results confirm and extend earlier observations of diphtheria toxin C-domain unfolding and refolding that must occur before and after vesicle membrane translocation. In addition, results presented here demonstrate that thioredoxin reductase activity plays an essential role in the cytosolic release of the C-domain. Because analogous CTF complexes have been partially purified from mammalian and yeast cell extracts, results presented here suggest a common and fundamental mechanism for C-domain translocation across early endosomal membranes.
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Affiliation(s)
- Ryan Ratts
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA.
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16
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Wesche J, Olsnes S. Ability of the Tat basic domain and VP22 to mediate cell binding, but not membrane translocation of the diphtheria toxin A-fragment. Biochemistry 2001; 40:4349-58. [PMID: 11284691 DOI: 10.1021/bi002443l] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A number of proteins are able to enter cells from the extracellular environment, including protein toxins, growth factors, viral proteins, homeoproteins, and others. Many such translocating proteins, or parts of them, appear to be able to carry with them cargo into the cell, and a basic sequence from the HIV-1 Tat protein has been reported to provide intracellular delivery of several fused proteins. For evaluating the efficiency of translocation to the cytosol, this TAT-peptide was fused to the diphtheria toxin A-fragment (dtA), an extremely potent inhibitor of protein synthesis which normally is delivered efficiently to the cytosol by the toxin B-fragment. The fusion of the TAT-peptide to dtA converted the protein to a heparin-binding protein that bound avidly to the cell surface. However, no cytotoxicity of this protein was detected, indicating that the TAT-peptide is unable to efficiently deliver enzymatically active dtA to the cytosol. Interestingly, the fused TAT-peptide potentiated the binding and cytotoxic effect of the corresponding holotoxin. We made a fusion protein between VP22, another membrane-permeant protein, and dtA, and also in this case we detected association with cells in the absence of a cytotoxic effect. The data indicate that transport of dtA into the cell by the TAT-peptide and VP22 is inefficient.
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17
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Wang Y, Kachel K, Pablo L, London E. Use of Trp mutations to evaluate the conformational behavior and membrane insertion of A and B chains in whole diphtheria toxin. Biochemistry 1997; 36:16300-8. [PMID: 9405065 DOI: 10.1021/bi971281z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The structure of diphtheria toxin was examined using its Trp fluorescence. To examine the interactions of the A and B chains of the toxin independently, mutants were constructed in which Trp residues were restricted to either the A or the B chain. The conformation and stability of the mutants were very similar to those of the wild-type protein. In addition, they underwent the low-pH conformational transition and membrane insertion at about the same pH as wild-type toxin. This shows Trp do not play a critical role in these processes which are necessary for the translocation of toxin across endosomal membranes in vivo. There was a shift in fluorescence of the Trp mutants which showed the low-pH-induced transition increases exposure of both the A and B Trp to a more polar environment. This supports a model in which the interdomain interactions present at neutral pH break down at low pH. To evaluate the location of the A and B chains in the membrane, the fluorescence quenching of model membrane inserted toxin was measured. Comparison of the amount of quenching by lipid labeled with nitroxides localized at shallow, medium, or deep depths within the bilayer demonstrated that both the A and B chains insert deeply, but the A chain Trp are somewhat less deeply inserted. Trp on the A chain are also less exposed to lipid than on the B chain, as judged by their weaker quenching by the nitroxide-labeled lipid. This conclusion was supported by the observation that the Trp of membrane-inserted isolated A chain is more lipid-exposed than when the A chain is part of the whole toxin. Both the A and B chain Trp become less exposed to lipid after neutralizing pH. However, both chains remain inserted, with at least part of the B chain remaining deeply inserted. These results support the "partial wrapper" model in which both the A and B chains are inserted but contacts between the two chains significantly reduce the exposure of the A chain to lipid.
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Affiliation(s)
- Y Wang
- Department of Biochemistry and Cell Biology, Institute for Cell and Developmental Biology, State University of New York at Stony Brook, Stony Brook, New York 11794-5215, USA
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18
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Lemichez E, Bomsel M, Devilliers G, vanderSpek J, Murphy JR, Lukianov EV, Olsnes S, Boquet P. Membrane translocation of diphtheria toxin fragment A exploits early to late endosome trafficking machinery. Mol Microbiol 1997; 23:445-57. [PMID: 9044279 DOI: 10.1111/j.1365-2958.1997.tb02669.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
After reaching early endosomes by receptor-mediated endocytosis, diphtheria toxin (DT) molecules have two possible fates. A large pool enters the degradative pathway whereas a few molecules become cytotoxic by translocating their catalytic fragment A (DTA) into the cytosol. Impairment of DT degradation by microtubule depolymerization does not block DT cytotoxicity. Therefore, DTA membrane translocation into the cytosol occurs from an endocytic compartment located upstream of late endosomes. Comparisons between early endosomes and endocytic carrier vesicles in a cell-free translocation assay have demonstrated that early endosomes are the earliest endocytic compartment from which DTA translocates. DTA translocation is ATP-dependent, requires early endosomal acidification, and is increased by the addition of cytosol. Cytosol-dependent DTA translocation is GTP gamma S-insensitive but is blocked by anti-beta COP antibodies.
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Affiliation(s)
- E Lemichez
- INSERM U452 Faculté de Médecine, Nice, France
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19
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Tortorella D, Sesardic D, Dawes CS, London E. Immunochemical analysis shows all three domains of diphtheria toxin penetrate across model membranes. J Biol Chem 1995; 270:27446-52. [PMID: 7499201 DOI: 10.1074/jbc.270.46.27446] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Diphtheria toxin undergoes membrane insertion and translocation across membranes when exposed to low pH. In this study, the translocation of the toxin has been investigated by the binding of antibodies to two preparations of model membrane-inserted toxin. In one preparation, toxin was added externally to model membrane vesicles and then inserted by exposure to low pH. In the other preparation, toxin was entrapped in the vesicles at neutral pH, and then inserted by decreasing pH. At neutral pH, externally added antibodies could not bind to entrapped toxin, although they could bind to externally added native toxin. However, after low pH exposure, antibodies against all three toxin domains (catalytic (C), transmembrane (T), and receptor-binding (R)) could bind to entrapped toxin, and also to externally added membrane-inserted toxin. The binding to the entrapped toxin shows that all three domains of the toxin translocate to the trans face of the membrane after exposure to low pH. The observation that antibodies bind to both external and entrapped preparations of toxin after low pH exposure shows that toxin inserts in a mixed orientation. A difference in antibody binding to low pH-treated toxin in which the C domain is folded (Lr' conformation) or unfolded (Lr" conformation) was also observed. An increase in antibody binding to C and T domains in the Lr" conformation relative to binding to the Lr' conformation was found for entrapped toxin, suggesting that more of the C and T domains translocate across the bilayer in the Lr" conformation. These results suggest all three toxin domains insert in the membrane bilayer and participate in translocation in vitro. The C and R domains lack classical transmembrane hydrophobic sequences. However, they possess sequences that have the potential to form membrane-inserting beta-sheets.
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Affiliation(s)
- D Tortorella
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook 11794-5215, USA
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20
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Falnes PO, Wiedłocha A, Rapak A, Olsnes S. Farnesylation of CaaX-tagged diphtheria toxin A-fragment as a measure of transfer to the cytosol. Biochemistry 1995; 34:11152-9. [PMID: 7669773 DOI: 10.1021/bi00035a021] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Diphtheria toxin binds to receptor-positive cells through its B-fragment, the toxin is then endocytosed, and the low pH in endosomes triggers the translocation of the enzymatically active A-fragment to the cytosol. A synchronous release of A-fragments into the cytosol can be induced by exposing cells with surface-bound toxin to low pH. We have used this protein translocation system to develop a novel method to study whether or not a protein is exposed to the cytosol. Protein farnesylation is a cytosolic modification signaled by a C-terminal CaaX motif, and to visualize the translocation process, we added a farnesylation signal to the toxin A-fragment. The A-fragment with an added CaaX motif was farnesylated within 1 h after exposure of cells with surface-bound toxin to low pH, and also A-fragment translocated from endosomes was quantitatively farnesylated. The results indicate that all cell-mediated reduction of the toxin implicates translocation of the A-fragment to the cytosol. The farnesylation was inhibited by lovastatin, the alkylating agent NEM, and the peptidomimetic farnesylation inhibitor B581. Farnesylated A-fragment partitioned preferentially into the detergent phase upon extraction with Triton X-114. Our data suggest that farnesylation of a CaaX tag is generally applicable as a cytosolic marker, and this strategy for monitoring protein transfer to the cytosol may have considerable potential for studying the transport to the cytosol of proteins added externally to cells.
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Affiliation(s)
- P O Falnes
- Institute for Cancer Research, Norwegian Radium Hospital, Montebello, Oslo
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21
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Falnes PO, Olsnes S. Cell-mediated reduction and incomplete membrane translocation of diphtheria toxin mutants with internal disulfides in the A fragment. J Biol Chem 1995; 270:20787-93. [PMID: 7657662 DOI: 10.1074/jbc.270.35.20787] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Active diphtheria toxin consists of two fragments, A and B, joined by a disulfide bond. The B fragment binds to cell surface receptors and aids in the translocation of the enzymatically active A fragment to the cytosol. Normally, the toxin A fragment enters the cytosol from acidic endosomes, but translocation can also be induced at the level of the plasma membrane by exposing cells with surface-bound toxin to low pH. Recently, we showed that disulfide bonds introduced into the A fragment by mutation are inhibitory for translocation. In the present work, we found that although the complete translocation of the A fragment is blocked, three mutant toxins underwent reduction of the interfragment disulfide bond upon low pH exposure, whereas the internal disulfide in the A fragment remained intact. In the case of two of these mutants, the A fragment was released into the extracellular medium upon exposure of cell-bound toxin to low pH. The pH profile for the release of the mutant A fragments was the same as for translocation of wild-type A fragment to the cytosol, and the release was inhibited by conditions that interfere with A fragment translocation. In the case of the third mutant, which remained cell-associated upon reduction of the interfragment disulfide bond, a translocation intermediate was detected. The results show that the reduction of the interfragment disulfide bond can occur in the absence of complete translocation of the A fragment to the cytosol, and they indicate that the reduction takes place at an early stage in the translocation process. Our findings suggest that the translocation of the A fragment across the membrane is initiated at the C terminus.
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Affiliation(s)
- P O Falnes
- Institute for Cancer Research, Norwegian Radium Hospital, Montebello, Oslo
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22
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Madshus I. The N-terminal alpha-helix of fragment B of diphtheria toxin promotes translocation of fragment A into the cytoplasm of eukaryotic cells. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32500-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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24
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Menestrina G, Schiavo G, Montecucco C. Molecular mechanisms of action of bacterial protein toxins. Mol Aspects Med 1994; 15:79-193. [PMID: 7984032 DOI: 10.1016/0098-2997(94)90043-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- G Menestrina
- Centro C.N.R. di Fisica degli Stati Aggregati, Povo, Trento, Italy
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25
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de Paiva A, Poulain B, Lawrence G, Shone C, Tauc L, Dolly J. A role for the interchain disulfide or its participating thiols in the internalization of botulinum neurotoxin A revealed by a toxin derivative that binds to ecto-acceptors and inhibits transmitter release intracellularly. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)36861-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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26
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Friedlander AM, Bhatnagar R, Leppla SH, Johnson L, Singh Y. Characterization of macrophage sensitivity and resistance to anthrax lethal toxin. Infect Immun 1993; 61:245-52. [PMID: 8380282 PMCID: PMC302711 DOI: 10.1128/iai.61.1.245-252.1993] [Citation(s) in RCA: 121] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Anthrax lethal toxin, which consists of two proteins, protective antigen and lethal factor, is cytolytic for macrophages. Macrophages from different mouse strains were found to vary in their sensitivities to toxin. C3H mouse macrophages lysed by lethal factor concentrations of 0.001 micrograms/ml were 100,000 times more sensitive than those from resistant A/J mice. We analyzed various stages of the intoxication process to determine the basis for this resistance. Direct binding studies with radioiodinated protective antigen revealed that the affinity (Kd, approximately 0.5 nM) and number of receptors per cell (25,000 to 33,000) were the same in sensitive and resistant cells. Proteolytic activation of protective antigen by a cell surface protease and subsequent binding of lethal factor were also the same in both sensitive and resistant macrophages. Resistant A/J macrophages were not cross-resistant to other toxins and a virus which, like lethal toxin, require vesicular acidification for activity, implying that resistance is not due to a defect in vesicular acidification. When introduced into the cytosol by osmotic lysis of pinosomes, lethal factor in the absence of protective antigen was cytolytic for the sensitive macrophages while resistant cells were unaffected. Thus, lethal factor by itself possesses the toxic activity of lethal toxin. These results suggest that macrophage resistance is due to a defect at a stage occurring after toxin internalization. A/J macrophages may lack the putative lethal factor target in the cytosol or be defective in the further processing or activation of lethal factor in the cytosol or in endocytic vesicles.
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Affiliation(s)
- A M Friedlander
- U.S. Army Medical Research Institute of Infectious Diseases, Frederick, Maryland 21702-5011
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27
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Novak J, Stein M, Little S, Leppla S, Friedlander A. Functional characterization of protease-treated Bacillus anthracis protective antigen. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41911-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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28
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Montecucco C, Papini E, Schiavo G, Padovan E, Rossetto O. Ion channel and membrane translocation of diphtheria toxin. FEMS MICROBIOLOGY IMMUNOLOGY 1992; 5:101-11. [PMID: 1384590 DOI: 10.1111/j.1574-6968.1992.tb05892.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Diphtheria toxin is the best studied member of a family of bacterial protein toxins which act inside cells. To reach their cytoplasmic targets, these toxins, which include tetanus and botulinum neurotoxins and anthrax toxin, have to cross the hydrophobic membrane barrier. All of them have been shown to form ion channels across planar lipid bilayer and, in the case of diphtheria toxin, also in the plasma membrane of cells. A relation between the ion channel and the process of membrane translocation has been suggested and two different models have been put forward to account for these phenomena. The two models are discussed on the basis of the available experimental evidence and in terms of the focal points of difference, amenable to further experimental investigations.
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Affiliation(s)
- C Montecucco
- Centro CNR Biomembrane and Istituto di Patologia Generale, Università di Padova, Italy
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29
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Naglich JG, Metherall JE, Russell DW, Eidels L. Expression cloning of a diphtheria toxin receptor: identity with a heparin-binding EGF-like growth factor precursor. Cell 1992; 69:1051-61. [PMID: 1606612 DOI: 10.1016/0092-8674(92)90623-k] [Citation(s) in RCA: 394] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A monkey cDNA (pDTS) encoding a diphtheria toxin (DT) sensitivity determinant was isolated by expression cloning in mouse L-M cells. Mouse cells are naturally resistant to DT, because they lack functional cell surface receptors for the toxin. Unlike wild-type L-M cells, pDTS-transfected mouse cells are extremely toxin sensitive and specifically bind radioiodinated DT. Intoxication of the transfected cells requires receptor-mediated endocytosis of the bound toxin. The cDNA is predicted to encode an integral membrane protein that is identical to the precursor of a heparin-binding EGF-like growth factor. The DT sensitivity protein is thus a growth factor precursor that DT exploits as a receptor.
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Affiliation(s)
- J G Naglich
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235
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30
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Beaumelle B, Bensammar L, Bienvenüe A. Selective translocation of the A chain of diphtheria toxin across the membrane of purified endosomes. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)49942-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Interactions of diphtheria toxin B-fragment with cells. Role of amino- and carboxyl-terminal regions. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50373-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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32
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London E. Diphtheria toxin: membrane interaction and membrane translocation. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1113:25-51. [PMID: 1550860 DOI: 10.1016/0304-4157(92)90033-7] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- E London
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook 11794-5215
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33
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Affiliation(s)
- I H Madshus
- Department of Biochemistry, Norwegian Radium Hospital, Oslo
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34
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35
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Ryser H, Mandel R, Ghani F. Cell surface sulfhydryls are required for the cytotoxicity of diphtheria toxin but not of ricin in Chinese hamster ovary cells. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55080-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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36
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Janicot M, Fouque F, Desbuquois B. Activation of rat liver adenylate cyclase by cholera toxin requires toxin internalization and processing in endosomes. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98773-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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37
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Stenmark H, Olsnes S, Madshus IH. Elimination of the disulphide bridge in fragment B of diphtheria toxin: effect on membrane insertion, channel formation, and ATP binding. Mol Microbiol 1991; 5:595-606. [PMID: 1646374 DOI: 10.1111/j.1365-2958.1991.tb00730.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Active diphtheria toxin consists of two disulphide-linked fragments, termed A and B. Fragment B, which contains an internal disulphide bridge, facilitates translocation of the enzymatically active fragment A to the cytosol of eukaryotic cells. In this process cation-selective channels are formed. An in vitro translated full-length mutant lacking the internal disulphide bridge (A-58**) was functionally indistinguishable from its disulphide-containing counterpart (A-58) with respect to trypsin sensitivity, receptor binding, A-fragment translocation, and channel formation. In contrast, the B fragment of A-58** (B-36**) was slightly less trypsin resistant than the S-S-containing B fragment, B-36, and was approximately 300-fold less efficient than B-36 in permeabilizing cells. When first dialysed and then reconstituted with A fragment, B fragment without disulphide bridge yielded a less-active toxin than did wild-type B fragment. We conclude that the disulphide bridge in fragment B is not necessary for toxicity, as earlier believed, and that channel formation may play a role in membrane translocation.
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Affiliation(s)
- H Stenmark
- Institute for Cancer Research, Norwegian Radium Hospital, Montebello, Oslo, Norway
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38
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Moskaug JO, Stenmark H, Olsnes S. Insertion of diphtheria toxin B-fragment into the plasma membrane at low pH. Characterization and topology of inserted regions. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52294-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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39
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Yoshida T, Chen CC, Zhang MS, Wu HC. Disruption of the Golgi apparatus by brefeldin A inhibits the cytotoxicity of ricin, modeccin, and Pseudomonas toxin. Exp Cell Res 1991; 192:389-95. [PMID: 1899070 DOI: 10.1016/0014-4827(91)90056-z] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have studied the cytotoxicity of ricin in cells treated with brefeldin A (BFA), which dramatically disrupts the structure of the Golgi apparatus causing Golgi content and membrane to redistribute to the ER. BFA inhibits the cytotoxicity of ricin in Chinese hamster ovary, normal rat kidney, and Vero cells and abolishes the enhancement of ricin cytotoxicity by NH4Cl, nigericin, swainsonine, and tunicamycin or by a mutation in endosomal acidification. BFA protects cells from the cytotoxicities of modeccin and Pseudomonas toxin, but has no effect on the intoxication by diphtheria toxin. Pretreatment of BFA does not protect cells from ricin treatment in the absence of BFA. Our results suggest that ricin, modeccin, and Pseudomonas toxin share a common pathway of intracellular transport from endosomes to the Golgi region where they are released into the cytosol. In contrast, the lack of protection of Vero cells from diphtheria toxin by BFA indicates that diphtheria toxin is released from acidified endosomes without involving the Golgi region.
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Affiliation(s)
- T Yoshida
- Department of Microbiology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799
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Abstract
Ribosome-inactivating plant toxic proteins and ADP-ribosylating microbial toxins share a common structural organization. These proteins present domains displaying different biological properties: a target cell membrane-binding component (B-subunit or haptomer) and an enzymatically active component (A-subunit or effectomer). Interactions of these toxins with the target cells are mediated by the hemilectin-like haptomer, which recognizes and specifically binds to a given glycoderivative present at the cell surface. After binding the holoprotein is internalized via endocytosis. Inside the endocytic compartment the toxin is processed to release its effectomer moiety which catalytically modifies a cytoplasmic component, and this step accounts for its toxic effect. The structural relationships between toxic hemilectins and plant lectins are discussed, with emphasis on the example of canatoxin and concanavalin A, both present in the seeds of the jack bean Canavalia ensiformis. Contrary to other plant toxic proteins, which inhibit protein synthesis, canatoxin-induced toxicity includes central nervous system-mediated effects. In vivo as well as in vitro canatoxin acts as lipoxygenase-mediated secretagogue in several types of cells: blood platelets, mast cells, pancreatic islets and synaptosomes. Elucidation of structure vs biological activity relationships of canatoxin and other toxic proteins may provide data for their utilization as pharmacological tools and as therapeutic agents.
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Affiliation(s)
- C R Carlini
- Department of Biochemistry, ICB, Universidade Federal do Rio de Janeiro, Brasil
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Feener E, Shen W, Ryser H. Cleavage of disulfide bonds in endocytosed macromolecules. A processing not associated with lysosomes or endosomes. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(17)30580-x] [Citation(s) in RCA: 169] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Ramsay G, Freire E. Linked thermal and solute perturbation analysis of cooperative domain interactions in proteins. Structural stability of diphtheria toxin. Biochemistry 1990; 29:8677-83. [PMID: 2271548 DOI: 10.1021/bi00489a024] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The temperature and guanidine hydrochloride (GuHCl) dependence of the structural stability of diphtheria toxin has been investigated by high-sensitivity differential scanning calorimetry. In 50 mM phosphate buffer at pH 8.0 and in the absence of GuHCl, the thermal unfolding of diphtheria toxin is characterized by a transition temperature (Tm) of 54.9 degrees C, a calorimetric enthalpy change (delta H) of 295 kcal/mol, and a van't Hoff to calorimetric enthalpy ratio of 0.57. Increasing the GuHCl concentration lowers the transition temperature and the calorimetric enthalpy change. At the same time, the van't Hoff to calorimetric enthalpy ratio increases until it reaches a value of 1 at 0.3 M GuHCl and remains constant thereafter. At low GuHCl concentrations (0-0.3 M), the thermal unfolding of diphtheria toxin is characterized by the presence of two transitions corresponding to the A and B domains of the protein. At higher GuHCl concentrations (0.3-1 M), the A domain is unfolded at all temperatures, and only one transition corresponding to the B domain is observed. Under these conditions, the most stable protein conformation at low temperatures is a partially folded state in which the A domain is unfolded and the B domain folded. A general model that explicitly considers the energetics of domain interactions has been developed in order to account for the stability and cooperative behavior of diphtheria toxin. It is shown that this cooperative domain interaction model correctly accounts for the temperature location as well as the shape and area of the calorimetric curves. Under physiological conditions, domain-domain interactions account for most of the structural stability of the A domain.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G Ramsay
- Department of Biology, Biocalorimetry Center, Johns Hopkins University, Baltimore, Maryland 21218
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Moskaug JØ, Sletten K, Sandvig K, Olsnes S. Translocation of Diphtheria Toxin A-fragment to the Cytosol. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84890-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Olsnes S, Stenmark H, McGill S, Hovig E, Collier RJ, Sandvig K. Formation of Active Diphtheria Toxin in vitro Based on Ligated Fragments of Cloned Mutant Genes. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51547-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Moskaug JØ, Sandvig K, Olsnes S. Role of Anions in Low pH-induced Translocation of Diphtheria Toxin. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60473-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Stenmark H, Olsnes S, Sandvig K. Requirement of specific receptors for efficient translocation of diphtheria toxin A fragment across the plasma membrane. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37726-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Olsnes S, Moskaug JO, Stenmark H, Sandvig K. Diphtheria toxin entry: protein translocation in the reverse direction. Trends Biochem Sci 1988; 13:348-51. [PMID: 3072713 DOI: 10.1016/0968-0004(88)90105-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Sandvig K, Olsnes S. Diphtheria toxin-induced channels in Vero cells selective for monovalent cations. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37762-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Moskaug JO, Sandvig K, Olsnes S. Low pH-induced release of diphtheria toxin A-fragment in Vero cells. Biochemical evidence for transfer to the cytosol. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)69237-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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