GSBS Student Publications

Title

The Tir-binding region of enterohaemorrhagic Escherichia coli intimin is sufficient to trigger actin condensation after bacterial-induced host cell signalling

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Molecular Genetics and Microbiology

Date

12-14-1999

Document Type

Article

Medical Subject Headings

Actins; *Adhesins, Bacterial; Bacterial Adhesion; Bacterial Outer Membrane Proteins; Bacterial Proteins; Binding Sites; Carcinoma, Hepatocellular; *Carrier Proteins; Cell Membrane; Escherichia coli; *Escherichia coli Proteins; Humans; Peptide Fragments; Receptors, Cell Surface; Recombinant Fusion Proteins; Signal Transduction; Tumor Cells, Cultured

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Enterohaemorrhagic Escherichia coli (EHEC) has emerged as an important agent of diarrhoeal disease. Attachment to host cells, an essential step during intestinal colonization by EHEC, is associated with the formation of a highly organized cytoskeletal structure containing filamentous actin, termed an attaching and effacing (A/E) lesion, directly beneath bound bacteria. The outer membrane protein intimin is required for the formation of this structure, as is Tir, a bacterial protein that is translocated into the host cell and is thought to function as a receptor for intimin. To understand intimin function better, we fused EHEC intimin to a homologous protein, Yersinia pseudotuberculosis invasin, or to maltose-binding protein. The N-terminal 539 amino acids of intimin were sufficient to promote outer membrane localization of the C-terminus of invasin and, conversely, the N-terminal 489 amino acids of invasin were sufficient to promote the localization of the C-terminus of intimin. The C-terminal 181 residues of intimin were sufficient to bind mammalian cells that had been preinfected with an enteropathogenic E. coli strain that expresses Tir but not intimin. Binding of intimin derivatives to preinfected cells correlated with binding to recombinant Tir protein. Finally, the 181-residue minimal Tir-binding region of intimin, when purified and immobilized on latex beads, was sufficient to trigger A/E lesions on preinfected mammalian cells.

Rights and Permissions

Citation: Mol Microbiol. 1999 Oct;34(1):67-81.

Related Resources

Link to article in PubMed

Journal Title

Molecular microbiology

PubMed ID

10540286