Transcriptional activation of Salmonella typhimurium invasion genes by a member of the phosphorylated response‐regulator superfamily
| Autor: | Christine Johnston, Catherine A. Lee, Samuel I. Miller, David A. Pegues, Christoph J. Hueck |
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| Rok vydání: | 1996 |
| Předmět: |
DNA
Bacterial Salmonella typhimurium Transcriptional Activation Salmonella Transcription Genetic Molecular Sequence Data Locus (genetics) Biology medicine.disease_cause Microbiology Bacterial Proteins Transcription (biology) Genes Regulator medicine Secretion Amino Acid Sequence Phosphorylation Molecular Biology Transcription factor Gene Base Sequence Sequence Homology Amino Acid Genetic Complementation Test Gene Expression Regulation Bacterial Molecular biology Pathogenicity island Response regulator Phenotype Mutagenesis Trans-Activators |
| Zdroj: | Molecular Microbiology. 22:715-727 |
| ISSN: | 1365-2958 0950-382X |
| DOI: | 10.1046/j.1365-2958.1996.d01-1719.x |
| Popis: | The Salmonella typhimurium PhoP-repressed locus prgHIJK encodes components of a sec-independent type III secretion apparatus. This apparatus is composed of at least 17 proteins encoded on a 40 kb pathogenicity Island located at centisome 63 on the S. typhimurium chromosome. The secretion apparatus and some of its targets, SapB, SapC and SspD, are necessary for epithelial cell invasion. The transcription of many invasion genes, including prgHIJK, is coordinately activated by HilA, a transcription factor encoded within the pathogenicity island. In this report we identify sirA, a gene located outside the pathogenicity island that is essential for induction of prgHIJK and hilA transcription. sirA encodes a 234-amino-acid protein that is essential for S. typhimurium Ssp (Salmonella secreted protein) secretion and invasion and is similar to response regulators of two-component regulatory systems. sirA-mutant phenotypes could be suppressed by two DNA clones from unlinked loci, designated sirB and sirC. These data suggest that SirA may be phosphorylated in response to S. typhimurium sensing a mammalian microenvironment. Furthermore, SirA phosphorylation is predicted to initiate a cascade of transcription-factor synthesis which results in invasion-gene transcription, Ssp secretion, and bacterial invasion of epithelia. |
| Databáze: | OpenAIRE |
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