JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Dasgupta, N.
Right arrow Articles by Ramphal, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dasgupta, N.
Right arrow Articles by Ramphal, R.

 Previous Article  |  Next Article 

Journal of Bacteriology, January 2000, p. 357-364, Vol. 182, No. 2
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

fleN, a Gene That Regulates Flagellar Number in Pseudomonas aeruginosa

Nandini Dasgupta, Shiwani K. Arora, and Reuben Ramphal*

Department of Medicine/Infectious Diseases, University of Florida, Gainesville, Florida 32610

Received 29 June 1999/Accepted 11 October 1999

The single polar flagellum of Pseudomonas aeruginosa plays an important role in the pathogenesis of infection by this organism. However, regulation of the assembly of this organelle has not been delineated. In analyzing the sequence available at the Pseudomonas genome database, an open reading frame (ORF), flanked by flagellar genes flhF and fliA, that coded for a protein (280 amino acids) with an ATP-binding motif at its N terminus was found. The ORF was inactivated by inserting a gentamicin cassette in P. aeruginosa PAK and PAO1. The resulting mutants were nonmotile on motility agar plates, but under a light microscope they exhibited random movement and tumbling behavior. Electron microscopic studies of the wild-type and mutant strains revealed that the mutants were multiflagellate, with three to six polar flagella per bacterium as rather than one as in the wild type, indicating that this ORF was involved in regulating the number of flagella and chemotactic motility in P. aeruginosa. The ORF was named fleN. An intact copy of fleN on a plasmid complemented the mutant by restoring motility and monoflagellate status. The beta -galactosidase activities of eight flagellar operon or gene promoters in the wild-type and fleN mutant strains revealed a direct correlation between six promoters that were upregulated in the fleN mutant (fliLMNOPQ, flgBCDE, fliEFG, fliDS orf126, fleSR, and fliC) and positive regulation by FleQ, an NtrC-like transcriptional regulator for flagellar genes. Based on these results, we propose a model where FleN influences FleQ activity (directly or indirectly) in regulating flagellar number in P. aeruginosa.


* Corresponding author. Mailing address: Department of Medicine/Infectious Diseases, P.O. Box 100277, JHMHC, University of Florida, Gainesville, FL 32610. Phone: (352) 392-2932. Fax: (352) 392-6481. E-mail: RAMPHR{at}medmac.ufl.edu.


Journal of Bacteriology, January 2000, p. 357-364, Vol. 182, No. 2
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.



This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2000 by the American Society for Microbiology. All rights reserved.