ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo
ExlA is a highly virulent pore-forming toxin that has been recently discovered in outlier strains from <i>Pseudomonas aeruginosa</i>. ExlA is part of a two-partner secretion system, in which ExlA is the secreted passenger protein and ExlB the transporter embedded in the bacterial outer m...
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MDPI AG
2021-09-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/13/9/645 |
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| author | Vincent Deruelle Alice Berry Stéphanie Bouillot Viviana Job Antoine P. Maillard Sylvie Elsen Philippe Huber |
| author_facet | Vincent Deruelle Alice Berry Stéphanie Bouillot Viviana Job Antoine P. Maillard Sylvie Elsen Philippe Huber |
| author_sort | Vincent Deruelle |
| collection | DOAJ |
| description | ExlA is a highly virulent pore-forming toxin that has been recently discovered in outlier strains from <i>Pseudomonas aeruginosa</i>. ExlA is part of a two-partner secretion system, in which ExlA is the secreted passenger protein and ExlB the transporter embedded in the bacterial outer membrane. In previous work, we observed that ExlA toxicity in a host cell was contact-dependent. Here, we show that ExlA accumulates at specific points of the outer membrane, is likely entrapped within ExlB pore, and is pointing outside. We further demonstrate that ExlA is maintained at the membrane in conditions where the intracellular content of second messenger cyclic-di-GMP is high; lowering c-di-GMP levels enhances ExlB-dependent ExlA secretion. In addition, we set up an ELISA to detect ExlA, and we show that ExlA is poorly secreted in liquid culture, while it is highly detectable in broncho-alveolar lavage fluids of mice infected with an <i>exlA</i>+ strain. We conclude that ExlA translocation is halted at mid-length in the outer membrane and its secretion is regulated by c-di-GMP. In addition, we developed an immunological test able to quantify ExlA in biological samples. |
| first_indexed | 2024-03-10T07:09:32Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-10T07:09:32Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-4ff63dca0eef4c6d8655c5385967db162023-11-22T15:31:25ZengMDPI AGToxins2072-66512021-09-0113964510.3390/toxins13090645ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In VivoVincent Deruelle0Alice Berry1Stéphanie Bouillot2Viviana Job3Antoine P. Maillard4Sylvie Elsen5Philippe Huber6Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceUnité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceUnité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceUnité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceUnité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceUnité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceUnité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, FranceExlA is a highly virulent pore-forming toxin that has been recently discovered in outlier strains from <i>Pseudomonas aeruginosa</i>. ExlA is part of a two-partner secretion system, in which ExlA is the secreted passenger protein and ExlB the transporter embedded in the bacterial outer membrane. In previous work, we observed that ExlA toxicity in a host cell was contact-dependent. Here, we show that ExlA accumulates at specific points of the outer membrane, is likely entrapped within ExlB pore, and is pointing outside. We further demonstrate that ExlA is maintained at the membrane in conditions where the intracellular content of second messenger cyclic-di-GMP is high; lowering c-di-GMP levels enhances ExlB-dependent ExlA secretion. In addition, we set up an ELISA to detect ExlA, and we show that ExlA is poorly secreted in liquid culture, while it is highly detectable in broncho-alveolar lavage fluids of mice infected with an <i>exlA</i>+ strain. We conclude that ExlA translocation is halted at mid-length in the outer membrane and its secretion is regulated by c-di-GMP. In addition, we developed an immunological test able to quantify ExlA in biological samples.https://www.mdpi.com/2072-6651/13/9/645bacterial pore-forming toxintwo-partner secretionc-di-GMP<i>Pseudomonas aeruginosa</i>toxin dosage |
| spellingShingle | Vincent Deruelle Alice Berry Stéphanie Bouillot Viviana Job Antoine P. Maillard Sylvie Elsen Philippe Huber ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo Toxins bacterial pore-forming toxin two-partner secretion c-di-GMP <i>Pseudomonas aeruginosa</i> toxin dosage |
| title | ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo |
| title_full | ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo |
| title_fullStr | ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo |
| title_full_unstemmed | ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo |
| title_short | ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo |
| title_sort | exla pore forming toxin localization at the bacterial membrane regulation of secretion by cyclic di gmp and detection in vivo |
| topic | bacterial pore-forming toxin two-partner secretion c-di-GMP <i>Pseudomonas aeruginosa</i> toxin dosage |
| url | https://www.mdpi.com/2072-6651/13/9/645 |
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