排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Marine Guillaud-Bataille Bruno Ragazzon Aurélien de Reyniès Claire Chevalier Isabelle Francillard Olivia Barreau Virginie Steunou Johann Guillemot Frédérique Tissier Marthe Rizk-Rabin Fernande René-Corail Abir Al Ghuzlan Guillaume Assié Xavier Bertagna Eric Baudin Yves Le Bouc Jér?me Bertherat Eric Clauser 《PloS one》2014,9(8)
5.
Anne Soisig Steunou Marion Babot Marie-Line Bourbon Reem Tambosi Anne Durand Sylviane Liotenberg Anja Krieger-Liszkay Yoshiharu Yamaichi Soufian Ouchane 《Microbial biotechnology》2020,13(5):1515-1529
Heavy metal contamination is a serious environmental problem. Understanding the toxicity mechanisms may allow to lower concentration of metals in the metal-based antimicrobial treatments of crops, and reduce metal content in soil and groundwater. Here, we investigate the interplay between metal efflux systems and the superoxide dismutase (SOD) in the purple bacterium Rubrivivax gelatinosus and other bacteria through analysis of the impact of metal accumulation. Exposure of the Cd2+-efflux mutant ΔcadA to Cd2+ caused an increase in the amount and activity of the cytosolic Fe-Sod SodB, thereby suggesting a role of SodB in the protection against Cd2+. In support of this conclusion, inactivation of sodB gene in the ΔcadA cells alleviated detoxification of superoxide and enhanced Cd2+ toxicity. Similar findings were described in the Cu+-efflux mutant with Cu+. Induction of the Mn-Sod or Fe-Sod in response to metals in other bacteria, including Escherichia coli, Pseudomonas aeruginosa, Pseudomonas putida, Vibrio cholera and Bacillus subtilis, was also shown. Both excess Cd2+ or Cu+ and superoxide can damage [4Fe-4S] clusters. The additive effect of metal and superoxide on the [4Fe-4S] could therefore explain the hypersensitive phenotype in mutants lacking SOD and the efflux ATPase. These findings underscore that ROS defence system becomes decisive for bacterial survival under metal excess. 相似文献
6.
7.
8.
9.
Anne Soisig Steunou Marie-Line Bourbon Marion Babot Anne Durand Sylviane Liotenberg Yoshiharu Yamaichi Soufian Ouchane 《Microbial biotechnology》2020,13(5):1530-1545
Pollution by copper (Cu2+) extensively used as antimicrobial in agriculture and farming represents a threat to the environment and human health. Finding ways to make microorganisms sensitive to lower metal concentrations could help decreasing the use of Cu2+ in agriculture. In this respect, we showed that limiting iron (Fe) uptake makes bacteria much more susceptible to Cu2+ or Cd2+ poisoning. Using efflux mutants of the purple bacterium Rubrivivax gelatinosus, we showed that Cu+ and Cd2+ resistance relies on the expression of the Fur-regulated FbpABC and Ftr iron transporters. To support this conclusion, inactivation of these Fe-importers in the Cu+ or Cd2+-ATPase efflux mutants gave rise to hypersensitivity towards these ions. Moreover, in metal overloaded cells the expression of FbpA, the periplasmic iron-binding component of the ferric ion transport FbpABC system was induced, suggesting that cells perceived an ‘iron-starvation’ situation and responded to it by inducing Fe-importers. In this context, the Fe-Sod activity increased in response to Fe homoeostasis dysregulation. Similar results were obtained for Vibrio cholerae and Escherichia coli, suggesting that perturbation of Fe-homoeostasis by metal excess appeared as an adaptive response commonly used by a variety of bacteria. The presented data support a model in which metal excess induces Fe-uptake to support [4Fe-4S] synthesis and thereby induce ROS detoxification system. 相似文献
10.
Asma Azzouzi Anne‐Soisig Steunou Anne Durand Bahia Khalfaoui‐Hassani Marie‐line Bourbon Chantal Astier David W. Bollivar Soufian Ouchane 《Molecular microbiology》2013,88(2):339-351
Two genes encoding structurally similar Copper P1B‐type ATPases can be identified in several genomes. Notwithstanding the high sequence and structural similarities these ATPases held, it has been suggested that they fulfil distinct physiological roles. In deed, we have shown that the Cu+‐ATPase CtpA is required only for the activity of cuproproteins in the purple bacterium Rubrivivax gelatinosus; herein, we show that CopA is not directly required for cytochrome c oxidase but is vital for copper tolerance. Interestingly, excess copper in the copA? mutant resulted in a substantial decrease of the cytochrome c oxidase and the photosystem under microaerobic and anaerobic conditions together with the extrusion of coproporphyrin III. The data indicated that copper targeted the tetrapyrrole biosynthesis pathway at the level of the coproporphyrinogen III oxidase HemN and thereby affects the oxidase and the photosystem. This is the first in vivo demonstration that copper, like oxygen, affects tetrapyrrole biosynthesis presumably at the level of the SAM and [4Fe‐4S] containing HemN enzyme. In light of these results and similar findings in Escherichia coli, the potential role of copper ions in the evolution of [4Fe‐4S] enzymes and the Cu+‐ATPases is discussed. 相似文献