Interaction of Ipa proteins of Shigella flexneri with alpha5beta1 integrin promotes entry of the bacteria into mammalian cells.

• DOI: 10.1084/jem.183.3.991
• Publication Date: 2004-06-24T07:56:10Z
• Authors: M Watarai; S Funato; C Sasakawa
• Keywords: 0301 basic medicine; 0303 health sciences; Microscopy, Confocal; CHO Cells; Protein-Tyrosine Kinases; Transfection; Recombinant Proteins; Shigella flexneri; 03 medical and health sciences; Receptors, Fibronectin; Bacterial Proteins; Cricetinae; Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; Animals; Humans; Adhesins, Bacterial; Phosphotyrosine; Cell Adhesion Molecules

Shigella is a genus of highly adapted bacterial pathogens that cause bacillary dysentery in humans. Bacteria reaching the colon invade intestinal epithelial cells by process bacterial-directed endocytosis mediated Ipa proteins: IpaB, IpaC, and IpaD Shigella. The invasion thought to be receptor-mediated phenomenon, although cellular components host interact with proteins have not yet been identified. We report here flexneri invasive system Chinese hamster ovary (CHO) cell monolayers, were capable interacting directly alpha5beta1 integrin. capacity S. for CHO increased as levels integrin elevated. When infected flexneri, tyrosine phosphorylation both pp 125FAK, an integrin-regulated 125 K focal adhesion kinase, paxillin was stimulated. In contrast, isogenic strain defective owing mutation its spa32 gene failed induce such phosphorylation. Under vitro vivo conditions, released bound alpha 5 beta 1 manner different from soluble fibronectin but similar tissue form fibronectin. At site attachment cells, converged polymerization actin. These data thus suggest may important factor triggering reorganization actin cytoskeletons.