HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplementary movie Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Lowenthal, A. C. Articles by Ottemann, K. M. Search for Related Content PubMed PubMed Citation Articles by Lowenthal, A. C. Articles by Ottemann, K. M. Agricola Articles by Lowenthal, A. C. Articles by Ottemann, K. M.

A fixed-time diffusion analysis method determines that the three cheV genes of Helicobacter pylori differentially affect motility

¹ Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
² Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
³ Department of Applied Mathematics and Statistics, University of California Santa Cruz, Santa Cruz, CA 95064, USA

Correspondence
Karen M. Ottemann
ottemann{at}ucsc.edu

Helicobacter pylori is a chemotactic bacterium that has three CheV proteins in its predicted chemotaxis signal transduction system. CheV proteins contain both CheW- and response-regulator-like domains. To determine the function of these proteins, we developed a fixed-time diffusion method that would quantify bacterial direction change without needing to define particular behaviours, to deal with the many behaviours that swimming H. pylori exhibit. We then analysed mutants that had each cheV gene deleted individually and found that the behaviour of each mutant differed substantially from wild-type and the other mutants. cheV1 and cheV2 mutants displayed smooth swimming behaviour, consistent with decreased cellular CheY-P, similar to a cheW mutant. In contrast, the cheV3 mutation had the opposite effect and the mutant cells appeared to change direction frequently. Additional analysis showed that the cheV mutants displayed aberrant behaviour as compared to the wild-type in the soft-agar chemotaxis assay. The soft-agar assay phenotype was less extreme compared to that seen in the fixed-time diffusion model, suggesting that the cheV mutants are able to partially compensate for their defects under some conditions. Each cheV mutant furthermore had defects in mouse colonization that ranged from severe to modest, consistent with a role in chemotaxis. These studies thus show that the H. pylori CheV proteins each differently affect swimming behaviour.

A supplementary movie showing an example of direction changes in the H. pylori cheV1 mutant is available with the online version of this paper.

This article has been cited by other articles:

				A. C. Lowenthal, M. Hill, L. K. Sycuro, K. Mehmood, N. R. Salama, and K. M. Ottemann Functional Analysis of the Helicobacter pylori Flagellar Switch Proteins J. Bacteriol., December 1, 2009; 191(23): 7147 - 7156. [Abstract] [Full Text] [PDF]