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
Google Scholar
Right arrow Articles by Labandeira-Rey, M.
Right arrow Articles by Hansen, E. J.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Labandeira-Rey, M.
Right arrow Articles by Hansen, E. J.

 Previous Article  |  Next Article 

Infection and Immunity, August 2009, p. 3402-3411, Vol. 77, No. 8
0019-9567/09/$08.00+0     doi:10.1128/IAI.00292-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Regulation of Expression of the Haemophilus ducreyi LspB and LspA2 Proteins by CpxR{triangledown}

Maria Labandeira-Rey, Jason R. Mock, and Eric J. Hansen*

Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390

Received 12 March 2009/ Returned for modification 31 March 2009/ Accepted 9 May 2009

The LspA1, LspA2, and LspB proteins of Haemophilus ducreyi comprise a two-partner secretion system that has been shown to be necessary for H. ducreyi to inhibit phagocytosis by immune cells in vitro. Inactivation of lspA1 resulted in increased levels of LspA2, suggesting that these two proteins are differentially controlled (C. J. Ward et al., Infect. Immun. 71:2478-2486, 2003). Expression of LspA2 but not LspA1 was shown to be both growth phase dependent and affected by the presence of fetal calf serum (FCS) in the growth medium. In addition, neither LspA1 nor LspA2 could be detected in culture supernatant fluid in the absence of FCS. DNA microarray analysis revealed that 324 H. ducreyi genes were differentially regulated after growth in the presence of FCS. Among these, the CpxRA two-component sensory transduction system was downregulated by the presence of FCS. Inactivation of cpxR resulted in increased expression of both LspB and LspA2. Electrophoretic mobility shift assays showed that a recombinant H. ducreyi CpxR protein bound the promoter region of the lspB-lspA2 operon. The cpxR and cpxA genes were shown to be part of an operon containing two additional genes in H. ducreyi 35000HP. This is the first description of a two-component sensory transduction system regulating a proven virulence factor of H. ducreyi.

* Corresponding author. Mailing address: Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9048. Phone: (214) 648-5974. Fax: (214) 648-5905. E-mail: eric.hansen{at}utsouthwestern.edu

{triangledown} Published ahead of print on 18 May 2009.

Editor: A. J. Bäumler

Infection and Immunity, August 2009, p. 3402-3411, Vol. 77, No. 8
0019-9567/09/$08.00+0     doi:10.1128/IAI.00292-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»