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V Foubister

Publications and source records attributed to V Foubister.

6 recordsLinked to original sources

A diarrheal pathogen, enteropathogenic Escherichia coli (EPEC), triggers a flux of inositol phosphates in infected epithelial cells.

Enteropathogenic Escherichia coli (EPEC) is a bacterial pathogen that causes diarrhea in infants by adhering to intestinal epithelial cells. EPEC induces host cell protein phosphorylation and increases intracellular calcium levels that may function to initiate cytoskeletal rearrangement. We found that EPEC triggers the release of inositol phosphates (IPs) after adherence of bacteria to cultured epithelial cells. We also demonstrated that the EPEC-induced flux of IPs precedes actin rearrangement and bacterial invasion. EPEC mutants and tyrosine protein kinase inhibitors were used to establish that formation of IPs is dependent on tyrosine phosphorylation of a 90-kD HeLa protein. Collectively these results suggest that EPEC-induced tyrosine phosphorylation of a host cell substrate(s) leads to release of IPs, which may then trigger cytoskeletal rearrangement.

Bacterial Adhesion↗

Salmonella typhimurium invasion of epithelial cells: role of induced host cell tyrosine protein phosphorylation.

Salmonella typhimurium invades nonphagocytic epithelial and fibroblast cells via a process resembling phagocytosis. We have compared some phenotypes that are involved in S. typhimurium invasion by using different host cell lines, including HeLa, Henle-407, and A431. Infection with either wild-type S. typhimurium, bacterial culture supernatant, or the noninvasive invA mutant was associated with induction of tyrosine phosphorylation of host cell mitogenic activating protein kinase. However, we did not detect induction of tyrosine phosphorylation of the epidermal growth factor receptor in S. typhimurium-infected cells. Treatment with the tyrosine protein kinase inhibitor genistein did not reduce S. typhimurium invasion into any of these cell lines. These results suggest that S. typhimurium invasion is independent of host cell epidermal growth factor receptor activation.

Calcium-Calmodulin-Dependent Protein Kinases↗

The eaeB gene of enteropathogenic Escherichia coli is necessary for signal transduction in epithelial cells.

An enteropathogenic Escherichia coli mutant carrying an internal deletion in the eaeB gene (UMD864) was unable to activate epithelial cell signals, including tyrosine phosphorylation, cytoskeletal rearrangements, and the release of inositol phosphates, indicating that the eaeB locus encodes a product that is involved in stimulating signals in epithelial cells.

Bacterial Outer Membrane Proteins↗