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The cytotoxic effect of diphtheria toxin on the actin cytoskeleton

Diphtheria toxin (DT) and its N-terminal fragment A (FA) catalyse the transfer of the ADP-ribose moiety of nicotinamide adenine dinucleotide (NAD) into a covalent linkage with eukaryotic elongation factor 2 (eEF2). DT-induced cytotoxicity is versatile, and it includes DNA cleavage and the depolymeri...

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Autores principales: Varol, Başak, Bektaş, Muhammet, Nurten, Rüstem, Bermek, Engin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SP Versita 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6275567/
https://www.ncbi.nlm.nih.gov/pubmed/22139586
http://dx.doi.org/10.2478/s11658-011-0036-6
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author Varol, Başak
Bektaş, Muhammet
Nurten, Rüstem
Bermek, Engin
author_facet Varol, Başak
Bektaş, Muhammet
Nurten, Rüstem
Bermek, Engin
author_sort Varol, Başak
collection PubMed
description Diphtheria toxin (DT) and its N-terminal fragment A (FA) catalyse the transfer of the ADP-ribose moiety of nicotinamide adenine dinucleotide (NAD) into a covalent linkage with eukaryotic elongation factor 2 (eEF2). DT-induced cytotoxicity is versatile, and it includes DNA cleavage and the depolymerisation of actin filaments. The inhibition of the ADP-ribosyltransferase (ADPrT) activity of FA did not affect the deoxyribonuclease activity of FA or its interaction with actin. The toxin entry rate into cells (HUVEC) was determined by measuring the ADP-ribosyltransferase activity. DT uptake was nearly 80% after 30 min. The efficiency was determined as K(m) = 2.2 nM; V(max) = 0.25 pmol.min(−1). The nuclease activity was tested with hyperchromicity experiments, and it was concluded that G-actin has an inhibitory effect on DT nuclease activity. In thepresence of DT and mutant of diphtheria toxin (CRM197), F-actin depolymerisation was determined with gel filtration, WB and fluorescence techniques. In the presence of DT and CRM197, 60–65% F-actin depolymerisation was observed. An in vitro FA-actin interaction and F-actin depolymerisation were reported in our previous paper. The present study thus confirms the depolymerisation of actin cytoskeleton in vivo.
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spelling pubmed-62755672018-12-10 The cytotoxic effect of diphtheria toxin on the actin cytoskeleton Varol, Başak Bektaş, Muhammet Nurten, Rüstem Bermek, Engin Cell Mol Biol Lett Research Article Diphtheria toxin (DT) and its N-terminal fragment A (FA) catalyse the transfer of the ADP-ribose moiety of nicotinamide adenine dinucleotide (NAD) into a covalent linkage with eukaryotic elongation factor 2 (eEF2). DT-induced cytotoxicity is versatile, and it includes DNA cleavage and the depolymerisation of actin filaments. The inhibition of the ADP-ribosyltransferase (ADPrT) activity of FA did not affect the deoxyribonuclease activity of FA or its interaction with actin. The toxin entry rate into cells (HUVEC) was determined by measuring the ADP-ribosyltransferase activity. DT uptake was nearly 80% after 30 min. The efficiency was determined as K(m) = 2.2 nM; V(max) = 0.25 pmol.min(−1). The nuclease activity was tested with hyperchromicity experiments, and it was concluded that G-actin has an inhibitory effect on DT nuclease activity. In thepresence of DT and mutant of diphtheria toxin (CRM197), F-actin depolymerisation was determined with gel filtration, WB and fluorescence techniques. In the presence of DT and CRM197, 60–65% F-actin depolymerisation was observed. An in vitro FA-actin interaction and F-actin depolymerisation were reported in our previous paper. The present study thus confirms the depolymerisation of actin cytoskeleton in vivo. SP Versita 2011-12-02 /pmc/articles/PMC6275567/ /pubmed/22139586 http://dx.doi.org/10.2478/s11658-011-0036-6 Text en © © Versita Warsaw and Springer-Verlag Wien 2011
spellingShingle Research Article
Varol, Başak
Bektaş, Muhammet
Nurten, Rüstem
Bermek, Engin
The cytotoxic effect of diphtheria toxin on the actin cytoskeleton
title The cytotoxic effect of diphtheria toxin on the actin cytoskeleton
title_full The cytotoxic effect of diphtheria toxin on the actin cytoskeleton
title_fullStr The cytotoxic effect of diphtheria toxin on the actin cytoskeleton
title_full_unstemmed The cytotoxic effect of diphtheria toxin on the actin cytoskeleton
title_short The cytotoxic effect of diphtheria toxin on the actin cytoskeleton
title_sort cytotoxic effect of diphtheria toxin on the actin cytoskeleton
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6275567/
https://www.ncbi.nlm.nih.gov/pubmed/22139586
http://dx.doi.org/10.2478/s11658-011-0036-6
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