SteC is a Salmonella kinase required for SPI-2-dependent F-actin remodelling
| Autor: | Mei Liu, Ad Spanos, David W. Holden, Paul S. Freemont, Charlotte Odendall, John Poh, Cliona Boyle |
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| Přispěvatelé: | Medical Research Council (MRC) |
| Rok vydání: | 2007 |
| Předmět: |
Salmonella typhimurium
animal diseases Mutant Vacuole Mice 1108 Medical Microbiology III SECRETION SYSTEM 0303 health sciences biology Virulence Kinase Effector ENTERICA SEROVAR TYPHIMURIUM Transfection ESCHERICHIA-COLI Salmonella enterica EFFECTORS RHO-KINASE Life Sciences & Biomedicine Sequence Analysis 0605 Microbiology CHROMOSOMAL GENES Immunology Microbiology Cell Line 03 medical and health sciences Virology Animals Humans Point Mutation Secretion Kinase activity VACUOLAR MEMBRANE 030304 developmental biology Science & Technology Sequence Homology Amino Acid 030306 microbiology Macrophages Epithelial Cells Cell Biology STRESS FIBERS Intracellular Membranes Original Articles PROTEIN-KINASE biochemical phenomena metabolism and nutrition biology.organism_classification bacterial infections and mycoses Actins Mutagenesis Insertional Vacuoles bacteria Protein Kinases Gene Deletion |
| Zdroj: | Cellular Microbiology |
| ISSN: | 1462-5822 |
| Popis: | Salmonella enterica serovar Typhimurium (S. Typhimurium) replicates inside mammalian cells within membrane‐bound compartments called Salmonella‐containing vacuoles. Intracellular replication is dependent on the activities of several effector proteins translocated across the vacuolar membrane by the Salmonella pathogenicity island 2 (SPI‐2)‐type III secretion system (T3SS). This is accompanied by the formation in the vicinity of bacterial vacuoles of an F‐actin meshwork, thought to be involved in maintaining the integrity of vacuolar membranes. In this study, we investigated the function of the SPI‐2 T3SS effector SteC. An steC mutant strain was not defective for intracellular replication or attenuated for virulence in mice. However, the steC mutant was defective for SPI‐2‐dependent F‐actin meshwork formation in host cells, although the vacuolar membranes surrounding mutant bacteria appeared to be normal. Expression of SteC in fibroblast cells following transfection caused extensive rearrangements of the F‐actin cytoskeleton. Sequence analysis identified amino acid similarity between SteC and the human kinase Raf‐1. A His‐tagged SteC fusion protein had kinase activity in vitro and a point mutant lacking kinase activity was unable to induce F‐actin rearrangements in vivo. We conclude that SPI‐2‐dependent F‐actin meshwork formation depends on the kinase activity of SteC, which resembles more closely eukaryotic than prokaryotic kinases. |
| Databáze: | OpenAIRE |
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