This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
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 Clock, S. A.
Right arrow Articles by Figurski, D. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Clock, S. A.
Right arrow Articles by Figurski, D. H.

 Previous Article  |  Next Article 

Journal of Bacteriology, February 2008, p. 980-990, Vol. 190, No. 3
0021-9193/08/$08.00+0     doi:10.1128/JB.01347-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

Outer Membrane Components of the Tad (Tight Adherence) Secreton of Aggregatibacter actinomycetemcomitans{triangledown} ,{dagger}

Sarah A. Clock,1 Paul J. Planet,2,3 Brenda A. Perez,1,{ddagger} and David H. Figurski1*

Department of Microbiology,1 Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, New York 10032,2 Molecular Laboratories, American Museum of Natural History, New York, New York 100243

Received 17 August 2007/ Accepted 20 November 2007

Prokaryotic secretion relies on proteins that are widely conserved, including NTPases and secretins, and on proteins that are system specific. The Tad secretion system in Aggregatibacter actinomycetemcomitans is dedicated to the assembly and export of Flp pili, which are needed for tight adherence. Consistent with predictions that RcpA forms the multimeric outer membrane secretion channel (secretin) of the Flp pilus biogenesis apparatus, we observed the RcpA protein in multimers that were stable in the presence of detergent and found that rcpA and its closely related homologs form a novel and distinct subfamily within a well-supported gene phylogeny of the entire secretin gene superfamily. We also found that rcpA-like genes were always linked to Aggregatibacter rcpB- or Caulobacter cpaD-like genes. Using antisera, we determined the localization and gross abundances of conserved (RcpA and TadC) and unique (RcpB, RcpC, and TadD) Tad proteins. The three Rcp proteins (RcpA, RcpB, and RcpC) and TadD, a putative lipoprotein, localized to the bacterial outer membrane. RcpA, RcpC, and TadD were also found in the inner membrane, while TadC localized exclusively to the inner membrane. The RcpA secretin was necessary for wild-type abundances of RcpB and RcpC, and TadC was required for normal levels of all three Rcp proteins. TadC abundance defects were observed in rcpA and rcpC mutants. TadD production was essential for wild-type RcpA and RcpB abundances, and RcpA did not multimerize or localize to the outer membrane without the expression of TadD. These data indicate that membrane proteins TadC and TadD may influence the assembly, transport, and/or function of individual outer membrane Rcp proteins.

* Corresponding author. Mailing address: Department of Microbiology, College of Physicians and Surgeons, Columbia University, 701 West 168th St., New York, NY 10032. Phone: (212) 305-3425. Fax: (212) 305-1468. E-mail: dhf2{at}columbia.edu

{triangledown} Published ahead of print on 30 November 2007.

{dagger} Supplemental material for this article may be found at http://jb.asm.org/.

{ddagger} Present address: Department of Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.

Journal of Bacteriology, February 2008, p. 980-990, Vol. 190, No. 3
0021-9193/08/$08.00+0     doi:10.1128/JB.01347-07
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Bernard, C. S., Bordi, C., Termine, E., Filloux, A., de Bentzmann, S. (2009). Organization and PprB-Dependent Control of the Pseudomonas aeruginosa tad Locus, Involved in Flp Pilus Biology. J. Bacteriol. 191: 1961-1973 [Abstract] [Full Text]  
  • Kram, K. E., Hovel-Miner, G. A., Tomich, M., Figurski, D. H. (2008). Transcriptional Regulation of the tad Locus in Aggregatibacter actinomycetemcomitans: a Termination Cascade. J. Bacteriol. 190: 3859-3868 [Abstract] [Full Text]  


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