This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by James, H. E. Articles by Lamont, I. L. Search for Related Content PubMed PubMed Citation Articles by James, H. E. Articles by Lamont, I. L.

 Previous Article  |  Next Article 

Journal of Bacteriology, July 2005, p. 4514-4520, Vol. 187, No. 13
0021-9193/05/$08.00+0     doi:10.1128/JB.187.13.4514-4520.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Mutational Analysis of a Bifunctional Ferrisiderophore Receptor and Signal-Transducing Protein from Pseudomonas aeruginosa

H. Ellen James, Paul A. Beare, Lois W. Martin, and Iain L. Lamont^*

Department of Biochemistry, University of Otago, Dunedin, New Zealand

Received 1 January 2005/ Accepted 1 April 2005

The FpvA protein of Pseudomonas aeruginosa strain PAO1 mediates uptake of a siderophore, ferripyoverdine. It is also a component of a signal transduction pathway that controls production of an exotoxin, a protease, pyoverdine, and FpvA itself. The purpose of the research described here was to dissect these different functions of FpvA. Signaling involves an N-terminal domain of FpvA, and it was shown that this domain is probably located in the periplasm, as expected. Short peptides were inserted at 36 sites within FpvA by linker insertion mutagenesis. The effects of these mutations on the presence of FpvA in the outer membrane, on FpvA-mediated uptake of ferripyoverdine, and on pyoverdine synthesis and gene expression were determined. Five of the mutations resulted in the absence of FpvA from the outer membrane of the bacteria. All of the remaining mutations eliminated either the transport or signaling function of FpvA and most affected both functions. Three mutations prevented transport of ferripyoverdine but had no effect on the signal transduction pathway showing that transport of ferripyoverdine is not required for the trans-membrane signaling process. Conversely, eight mutations affected pyoverdine-mediated signaling but had no effect on transport of ferripyoverdine. These data show that insertions throughout FpvA resulted in loss of function and that signaling and transport are separate and discrete functions of FpvA.

Present address: National Institute of Allergies and Infectious Diseases, National Institute of Health, 903 South 4th Street, Hamilton, MT 59840.

This article has been cited by other articles:

• Spencer, M. R., Beare, P. A., Lamont, I. L. (2008). Role of Cell Surface Signaling in Proteolysis of an Alternative Sigma Factor in Pseudomonas aeruginosa. J. Bacteriol. 190: 4865-4869 [Abstract] [Full Text]  
• Jones, A. M., Lindow, S. E., Wildermuth, M. C. (2007). Salicylic Acid, Yersiniabactin, and Pyoverdin Production by the Model Phytopathogen Pseudomonas syringae pv. tomato DC3000: Synthesis, Regulation, and Impact on Tomato and Arabidopsis Host Plants. J. Bacteriol. 189: 6773-6786 [Abstract] [Full Text]  
• Cwerman, H., Wandersman, C., Biville, F. (2006). Heme and a Five-Amino-Acid Hemophore Region Form the Bipartite Stimulus Triggering the has Signaling Cascade. J. Bacteriol. 188: 3357-3364 [Abstract] [Full Text]  
• Shen, J.-S., Geoffroy, V., Neshat, S., Jia, Z., Meldrum, A., Meyer, J.-M., Poole, K. (2005). FpvA-Mediated Ferric Pyoverdine Uptake in Pseudomonas aeruginosa: Identification of Aromatic Residues in FpvA Implicated in Ferric Pyoverdine Binding and Transport. J. Bacteriol. 187: 8511-8515 [Abstract] [Full Text]