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Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size

RTX (Repeats in ToXin) pore-forming toxins constitute an expanding family of exoproteins secreted by many Gram-negative bacteria and involved in infectious diseases caused by said pathogens. Despite the relevance in the host/pathogen interactions, the structure and characteristics of the lesions for...

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Autores principales: González-Bullón, David, B. Uribe, Kepa, Largo, Eneko, Guembelzu, Garazi, García-Arribas, Aritz B., Martín, César, Ostolaza, Helena
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572617/
https://www.ncbi.nlm.nih.gov/pubmed/31083482
http://dx.doi.org/10.3390/biom9050183
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author González-Bullón, David
B. Uribe, Kepa
Largo, Eneko
Guembelzu, Garazi
García-Arribas, Aritz B.
Martín, César
Ostolaza, Helena
author_facet González-Bullón, David
B. Uribe, Kepa
Largo, Eneko
Guembelzu, Garazi
García-Arribas, Aritz B.
Martín, César
Ostolaza, Helena
author_sort González-Bullón, David
collection PubMed
description RTX (Repeats in ToXin) pore-forming toxins constitute an expanding family of exoproteins secreted by many Gram-negative bacteria and involved in infectious diseases caused by said pathogens. Despite the relevance in the host/pathogen interactions, the structure and characteristics of the lesions formed by these toxins remain enigmatic. Here, we capture the first direct nanoscale pictures of lytic pores formed by an RTX toxin, the Adenylate cyclase (ACT), secreted by the whooping cough bacterium Bordetella pertussis. We reveal that ACT associates into growing-size oligomers of variable stoichiometry and heterogeneous architecture (lines, arcs, and rings) that pierce the membrane, and that, depending on the incubation time and the toxin concentration, evolve into large enough “holes” so as to allow the flux of large molecular mass solutes, while vesicle integrity is preserved. We also resolve ACT assemblies of similar variable stoichiometry in the cell membrane of permeabilized target macrophages, proving that our model system recapitulates the process of ACT permeabilization in natural membranes. Based on our data we propose a non-concerted monomer insertion and sequential mechanism of toroidal pore formation by ACT. A size-tunable pore adds a new regulatory element to ACT-mediated cytotoxicity, with different pore sizes being putatively involved in different physiological scenarios or cell types.
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spelling pubmed-65726172019-06-18 Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size González-Bullón, David B. Uribe, Kepa Largo, Eneko Guembelzu, Garazi García-Arribas, Aritz B. Martín, César Ostolaza, Helena Biomolecules Article RTX (Repeats in ToXin) pore-forming toxins constitute an expanding family of exoproteins secreted by many Gram-negative bacteria and involved in infectious diseases caused by said pathogens. Despite the relevance in the host/pathogen interactions, the structure and characteristics of the lesions formed by these toxins remain enigmatic. Here, we capture the first direct nanoscale pictures of lytic pores formed by an RTX toxin, the Adenylate cyclase (ACT), secreted by the whooping cough bacterium Bordetella pertussis. We reveal that ACT associates into growing-size oligomers of variable stoichiometry and heterogeneous architecture (lines, arcs, and rings) that pierce the membrane, and that, depending on the incubation time and the toxin concentration, evolve into large enough “holes” so as to allow the flux of large molecular mass solutes, while vesicle integrity is preserved. We also resolve ACT assemblies of similar variable stoichiometry in the cell membrane of permeabilized target macrophages, proving that our model system recapitulates the process of ACT permeabilization in natural membranes. Based on our data we propose a non-concerted monomer insertion and sequential mechanism of toroidal pore formation by ACT. A size-tunable pore adds a new regulatory element to ACT-mediated cytotoxicity, with different pore sizes being putatively involved in different physiological scenarios or cell types. MDPI 2019-05-10 /pmc/articles/PMC6572617/ /pubmed/31083482 http://dx.doi.org/10.3390/biom9050183 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
González-Bullón, David
B. Uribe, Kepa
Largo, Eneko
Guembelzu, Garazi
García-Arribas, Aritz B.
Martín, César
Ostolaza, Helena
Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size
title Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size
title_full Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size
title_fullStr Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size
title_full_unstemmed Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size
title_short Membrane Permeabilization by Bordetella Adenylate Cyclase Toxin Involves Pores of Tunable Size
title_sort membrane permeabilization by bordetella adenylate cyclase toxin involves pores of tunable size
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572617/
https://www.ncbi.nlm.nih.gov/pubmed/31083482
http://dx.doi.org/10.3390/biom9050183
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