This Article Full Text Full Text (PDF) Other Versions of this Article: JB.01427-06v1 189/5/1856    most recent 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 Ashgar, S. S. A. Articles by Ala'Aldeen, D. A. A. Search for Related Content PubMed PubMed Citation Articles by Ashgar, S. S. A. Articles by Ala'Aldeen, D. A. A.

 Previous Article  |  Next Article 

Journal of Bacteriology, March 2007, p. 1856-1865, Vol. 189, No. 5
0021-9193/07/$08.00+0     doi:10.1128/JB.01427-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

CapA, an Autotransporter Protein of Campylobacter jejuni, Mediates Association with Human Epithelial Cells and Colonization of the Chicken Gut

Sami S. A. Ashgar,^1, Neil J. Oldfield,^1, Karl G. Wooldridge,¹ Michael A. Jones,^2, Greg J. Irving,¹ David P. J. Turner,^1, and Dlawer A. A. Ala'Aldeen^1,*

Molecular Bacteriology and Immunology Group, Institute of Infection, Immunity, and Inflammation, School of Molecular Medical Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH,¹ Institute for Animal Health, Compton, Berkshire RG20 7NN, United Kingdom²

Received 8 September 2006/ Accepted 8 December 2006

Two putative autotransporter proteins, CapA and CapB, were identified in silico from the genome sequence of Campylobacter jejuni NCTC11168. The genes encoding each protein contain homopolymeric tracts, suggestive of phase variation mediated by a slipped-strand mispairing mechanism; in each case the gene sequence contained frameshifts at these positions. The C-terminal two-thirds of the two genes, as well as a portion of the predicted signal peptides, were identical; the remaining N-terminal portions were gene specific. Both genes were cloned and expressed; recombinant polypeptides were purified and used to raise rabbit polyclonal monospecific antisera. Using immunoblotting, expression of the ca.116-kDa CapA protein was demonstrated for in vitro-grown cells of strain NCTC11168, for 4 out of 11 recent human fecal isolates, and for 2 out of 8 sequence-typed strains examined. Expression of CapB was not detected for any of the strains tested. Surface localization of CapA was demonstrated by subcellular fractionation and immunogold electron microscopy. Export of CapA was inhibited by globomycin, reinforcing the bioinformatic prediction that the protein is a lipoprotein. A capA insertion mutant had a significantly reduced capacity for association with and invasion of Caco-2 cells and failed to colonize and persist in chickens, indicating that CapA plays a role in host association and colonization by Campylobacter. In view of this demonstrated role, we propose that CapA stands for Campylobacter adhesion protein A.

Published ahead of print on 15 December 2006.

S.S.A.A. and N.J.O. contributed equally to the present study.

Present address: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Leicestershire LE12 5RD, United Kingdom.

D.P.J.T. and D.A.A.A. also contributed equally to the present study.

This article has been cited by other articles:

• Tu, Q. V., McGuckin, M. A., Mendz, G. L. (2008). Campylobacter jejuni response to human mucin MUC2: modulation of colonization and pathogenicity determinants. J Med Microbiol 57: 795-802 [Abstract] [Full Text]  
• Guo, B., Wang, Y., Shi, F., Barton, Y.-W., Plummer, P., Reynolds, D. L., Nettleton, D., Grinnage-Pulley, T., Lin, J., Zhang, Q. (2008). CmeR Functions as a Pleiotropic Regulator and Is Required for Optimal Colonization of Campylobacter jejuni In Vivo. J. Bacteriol. 190: 1879-1890 [Abstract] [Full Text]