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) 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 Shaw, R. K. Articles by Knutton, S. Search for Related Content PubMed PubMed Citation Articles by Shaw, R. K. Articles by Knutton, S. Agricola Articles by Shaw, R. K. Articles by Knutton, S.

Enteropathogenic Escherichia coli translocate Tir and form an intimin–Tir intimate attachment to red blood cell membranes

Institute of Child Health, University of Birmingham, Birmingham B4 6NH, UK¹
Centre for Molecular Microbiology and Immunology, Department of Biosciences, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK²

Author for correspondence: Stuart Knutton. Tel: +44 121 333 8746. Fax: +44 121 333 8701. e-mail: s.knutton{at}bham.ac.uk

Type III secretion allows bacteria to inject effector proteins into host cells. In enteropathogenic Escherichia coli (EPEC) the type III secreted protein, Tir, is translocated to the host-cell plasma membrane where it functions as a receptor for the bacterial adhesin intimin, leading to intimate bacterial attachment and ‘attaching and effacing’ (A/E) lesion formation. To study EPEC type III secretion the interaction of EPEC with monolayers of red blood cells (RBCs) has been exploited and in a recent study [Shaw, R. K., Daniell, S., Ebel, F., Frankel, G. & Knutton, S. (2001 ). Cell Microbiol 3, 213–222] it was shown that EPEC induced haemolysis of RBCs and translocation of EspD, a putative pore-forming type III secreted protein in the RBC membrane. Here it is demonstrated that EPEC are able to translocate and correctly insert Tir into the RBC membrane and produce an intimin–Tir intimate bacterial attachment, identical to that seen in A/E lesions. Following translocation Tir did not undergo any change in apparent molecular mass or become tyrosine-phosphorylated and there was no focusing of RBC cytoskeletal actin beneath intimately adherent bacteria, and no pedestal formation. This study, employing an RBC model of infection, has demonstrated that Tir translocation can be separated from host-cell-mediated Tir modifications; the data show that the EPEC type III protein translocation apparatus is sufficient to deliver and correctly insert Tir into host-cell membranes independent of eukaryotic cell functions.

Keywords: type III secretion, adhesion, cell–cell interactions, EPEC

Abbreviations: A/E, attaching and effacing; DAPI, diamidino-2-phenylindole; EPEC, enteropathogenic Escherichia coli; RBC, red blood cell

This article has been cited by other articles:

				Y. Shifrin, A. Peleg, O. Ilan, C. Nadler, S. Kobi, K. Baruch, G. Yerushalmi, T. Berdichevsky, S. Altuvia, M. Elgrably-Weiss, et al. Transient Shielding of Intimin and the Type III Secretion System of Enterohemorrhagic and Enteropathogenic Escherichia coli by a Group 4 Capsule J. Bacteriol., July 15, 2008; 190(14): 5063 - 5074. [Abstract] [Full Text] [PDF]

				W. Luo and M. S. Donnenberg Analysis of the Function of Enteropathogenic Escherichia coli EspB by Random Mutagenesis Infect. Immun., February 1, 2006; 74(2): 810 - 820. [Abstract] [Full Text] [PDF]

				S. Dahan, S. Knutton, R. K. Shaw, V. F. Crepin, G. Dougan, and G. Frankel Transcriptome of Enterohemorrhagic Escherichia coli O157 Adhering to Eukaryotic Plasma Membranes Infect. Immun., September 1, 2004; 72(9): 5452 - 5459. [Abstract] [Full Text] [PDF]

				J. Cleary, L.-C. Lai, R. K. Shaw, A. Straatman-Iwanowska, M. S. Donnenberg, G. Frankel, and S. Knutton Enteropathogenic Escherichia coli (EPEC) adhesion to intestinal epithelial cells: role of bundle-forming pili (BFP), EspA filaments and intimin Microbiology, March 1, 2004; 150(3): 527 - 538. [Abstract] [Full Text] [PDF]

				S. C. Clarke, R. D. Haigh, P. P. E. Freestone, and P. H. Williams Virulence of Enteropathogenic Escherichia coli, a Global Pathogen Clin. Microbiol. Rev., July 1, 2003; 16(3): 365 - 378. [Abstract] [Full Text] [PDF]