| Growth-phase-dependent expression of the operon coding for the glycosylated autotransporter adhesin AIDA-I of pathogenic Escherichia coli. | |
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MedLine Citation:
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PMID: 20831592 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The adhesin involved in diffuse adherence (AIDA-I) is an autotransporter found in pathogenic strains of Escherichia coli causing diarrhea in humans and pigs. The AIDA-I protein is glycosylated by a specific enzyme, the AIDA-associated heptosyltransferase (Aah). The aah gene is immediately upstream of the aidA gene, suggesting that they form an operon. However, the mechanisms of regulation of the aah and aidA genes are unknown. Using a clinical E. coli isolate expressing AIDA-I, we identified two putative promoters 149 and 128 nucleotides upstream of aah. Using qRT-PCR, we observed that aah and aidA are transcribed in a growth-dependent fashion, mainly at the start of the stationary phase. Western blotting confirmed that protein expression follows the same pattern. Using a fusion to a reporter gene, we observed that the regulation of the isolated aah promoter matched this transcription and expression pattern. Lastly, we found glucose to be a repressor and nutrient starvation to be an inducer. Taken together, our results suggest that, in the strain and the conditions we studied, aah-aidA is transcribed as a bicistronic message from a promoter upstream of aah, with maximal expression under conditions of nutrient limitation such as high cell density. |
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Authors:
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Frédéric Berthiaume; Marie-Florence Leblond; Josée Harel; Michael Mourez |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-09-10 |
Journal Detail:
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Title: FEMS microbiology letters Volume: 311 ISSN: 1574-6968 ISO Abbreviation: FEMS Microbiol. Lett. Publication Date: 2010 Oct |
Date Detail:
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Created Date: 2010-09-23 Completed Date: 2011-01-05 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 7705721 Medline TA: FEMS Microbiol Lett Country: England |
Other Details:
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Languages: eng Pagination: 176-84 Citation Subset: IM |
Copyright Information:
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© 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved. |
Affiliation:
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Department of Bacterial Animal Diseases, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adhesins, Escherichia coli
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genetics*,
metabolism Base Sequence Escherichia coli / genetics, growth & development*, metabolism, pathogenicity Escherichia coli Infections / microbiology Escherichia coli Proteins / genetics, metabolism Gene Expression Regulation, Bacterial* Glycosylation Glycosyltransferases / genetics, metabolism Humans Molecular Sequence Data Operon* Promoter Regions, Genetic |
| Grant Support | |
ID/Acronym/Agency:
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84578//Canadian Institutes of Health Research |
| Chemical | |
Reg. No./Substance:
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0/AIDA-I protein, E coli; 0/Adhesins, Escherichia coli; 0/Escherichia coli Proteins; EC 2.4.-/Glycosyltransferases; EC 2.4.99.-/autotransporter-adhesin-heptosyltransferase, E coli |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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