Adaptation of aerobically growing Pseudomonas aeruginosa to copper starvation.
Restricted bioavailability of copper in certain environments can interfere with cellular respiration because copper is an essential cofactor of most terminal oxidases. The global response of the metabolically versatile bacterium and opportunistic pathogen Pseudomonas aeruginosa to copper limitation was assessed under aerobic conditions. Expression of cioAB (encoding an alternative, copper-independent, cyanide-resistant ubiquinol oxidase) was upregulated, whereas numerous iron uptake functions (including the siderophores pyoverdine and pyochelin) were expressed at reduced levels, presumably reflecting a lower demand for iron by respiratory enzymes. Wild-type P. aeruginosa was able to grow aerobically in a defined glucose medium depleted of copper, whereas a cioAB mutant did not grow. Thus, P. aeruginosa relies on the CioAB enzyme to cope with severe copper deprivation. A quadruple cyo cco1 cco2 cox mutant, which was deleted for all known heme-copper terminal oxidases of P. aeruginosa, grew aerobically, albeit more slowly than did the wild type, indicating that the CioAB enzyme is capable of energy conservation. However, the expression of a cioA'-'lacZ fusion was less dependent on the copper status in the quadruple mutant than in the wild type, suggesting that copper availability might affect cioAB expression indirectly, via the function of the heme-copper oxidases.
Frangipani
Emanuela
E
Département de Microbiologie Fondamentale, Université de Lausanne, Bâtiment Biophore, CH-1015 Lausanne, Switzerland.
Slaveykova
Vera I
VI
Reimmann
Cornelia
C
Haas
Dieter
D
D000332:Aerobiosis; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D003300:Copper / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D015536:Down-Regulation; D017353:Gene Deletion; D020869:Gene Expression Profiling; D017930:Genes, Reporter; D005947:Glucose / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D015854:Up-Regulation; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D001426:Bacterial Proteins; D003470:Culture Media; D011993:Recombinant Fusion Proteins; D003300:Copper; D001616:beta-Galactosidase; D005947:Glucose