Publications
2022
Normant Vincent, Kuhn Lauriane, Munier Mathilde, Hammann Philippe, Mislin Gaëtan L. A., Schalk Isabelle J.
How the Presence of Hemin Affects the Expression of the Different Iron Uptake Pathways in Pseudomonas aeruginosa Cells Journal Article
In: ACS infectious diseases, vol. 8, no. 1, pp. 183–196, 2022, ISSN: 2373-8227.
Abstract | Links | BibTeX | Tags: Hemin, hemin (heme) uptake, Iron, iron homeostasis, iron uptake, outer membrane transporters, PPSE, proteomics, Pseudomonas aeruginosa, siderophore, Siderophores
@article{normant_how_2022,
title = {How the Presence of Hemin Affects the Expression of the Different Iron Uptake Pathways in Pseudomonas aeruginosa Cells},
author = {Vincent Normant and Lauriane Kuhn and Mathilde Munier and Philippe Hammann and Gaëtan L. A. Mislin and Isabelle J. Schalk},
doi = {10.1021/acsinfecdis.1c00525},
issn = {2373-8227},
year = {2022},
date = {2022-01-01},
journal = {ACS infectious diseases},
volume = {8},
number = {1},
pages = {183--196},
abstract = {Iron is an essential nutriment for almost all organisms, but this metal is poorly bioavailable. During infection, bacteria access iron from the host by importing either iron or heme. Pseudomonas aeruginosa, a gram-negative pathogen, secretes two siderophores, pyoverdine (PVD) and pyochelin (PCH), to access iron and is also able to use many siderophores produced by other microorganisms (called xenosiderophores). To access heme, P. aeruginosa uses three distinct uptake pathways, named Has, Phu, and Hxu. We previously showed that P. aeruginosa expresses the Has and Phu heme uptake systems and the PVD- and PCH-dependent iron uptake pathways in iron-restricted growth conditions, using proteomic and RT-qPCR approaches. Here, using the same approaches, we show that physiological concentrations of hemin in the bacterial growth medium result in the repression of the expression of the proteins of the PVD- and PCH-dependent iron uptake pathways, leading to less production of these two siderophores. This indicates that the pathogen adapts its phenotype to use hemin as an iron source rather than produce PVD and PCH to access iron. Moreover, the presence of both hemin and a xenosiderophore resulted in (i) the strong induction of the expression of the proteins of the added xenosiderophore uptake pathway, (ii) repression of the PVD- and PCH-dependent iron uptake pathways, and (iii) no effect on the expression levels of the Has, Phu, or Hxu systems, indicating that bacteria use both xenosiderophores and heme to access iron.},
keywords = {Hemin, hemin (heme) uptake, Iron, iron homeostasis, iron uptake, outer membrane transporters, PPSE, proteomics, Pseudomonas aeruginosa, siderophore, Siderophores},
pubstate = {published},
tppubtype = {article}
}
2021
Gasser Véronique, Kuhn Lauriane, Hubert Thibaut, Aussel Laurent, Hammann Philippe, Schalk Isabelle J.
The Esterase PfeE, the Achilles' Heel in the Battle for Iron between Pseudomonas aeruginosa and Escherichia coli Journal Article
In: International Journal of Molecular Sciences, vol. 22, no. 6, pp. 2814, 2021, ISSN: 1422-0067.
Abstract | Links | BibTeX | Tags: Carrier Proteins, co-cultures, enterobactin, Escherichia coli, Escherichia coli Proteins, Esterases, Iron, iron homeostasis, iron uptake, outer membrane transporters, PPSE, Pseudomonas aeruginosa, siderophore, TonB
@article{gasser_esterase_2021,
title = {The Esterase PfeE, the Achilles' Heel in the Battle for Iron between Pseudomonas aeruginosa and Escherichia coli},
author = {Véronique Gasser and Lauriane Kuhn and Thibaut Hubert and Laurent Aussel and Philippe Hammann and Isabelle J. Schalk},
doi = {10.3390/ijms22062814},
issn = {1422-0067},
year = {2021},
date = {2021-03-01},
urldate = {2021-03-01},
journal = {International Journal of Molecular Sciences},
volume = {22},
number = {6},
pages = {2814},
abstract = {Bacteria access iron, a key nutrient, by producing siderophores or using siderophores produced by other microorganisms. The pathogen Pseudomonas aeruginosa produces two siderophores but is also able to pirate enterobactin (ENT), the siderophore produced by Escherichia coli. ENT-Fe complexes are imported across the outer membrane of P. aeruginosa by the two outer membrane transporters PfeA and PirA. Iron is released from ENT in the P. aeruginosa periplasm by hydrolysis of ENT by the esterase PfeE. We show here that pfeE gene deletion renders P. aeruginosa unable to grow in the presence of ENT because it is unable to access iron via this siderophore. Two-species co-cultures under iron-restricted conditions show that P. aeruginosa strongly represses the growth of E. coli as long it is able to produce its own siderophores. Both strains are present in similar proportions in the culture as long as the siderophore-deficient P. aeruginosa strain is able to use ENT produced by E. coli to access iron. If pfeE is deleted, E. coli has the upper hand in the culture and P. aeruginosa growth is repressed. Overall, these data show that PfeE is the Achilles' heel of P. aeruginosa in communities with bacteria producing ENT.},
keywords = {Carrier Proteins, co-cultures, enterobactin, Escherichia coli, Escherichia coli Proteins, Esterases, Iron, iron homeostasis, iron uptake, outer membrane transporters, PPSE, Pseudomonas aeruginosa, siderophore, TonB},
pubstate = {published},
tppubtype = {article}
}