Extracellular life cycle of ComS, the competence-stimulating peptide of Streptococcus thermophilus
| Autor: | Laetitia Fontaine, Christophe Gitton, Alain Guillot, Véronique Monnet, Rozenn Gardan, Colette Besset, Pascal Hols |
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| Přispěvatelé: | UCL - SST/ISV - Institut des sciences de la vie, MICrobiologie de l'ALImentation au Service de la Santé (MICALIS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Inst Sci Vie Biochim & Genet Mol Bacterienne, Université Catholique de Louvain = Catholic University of Louvain (UCL), Institut National de la Recherche Agronomique (INRA), Ile-de-France regional council, ISTREA, FNRS, Université Catholique de Louvain (UCL) |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
[SDV.SA]Life Sciences [q-bio]/Agricultural sciences
Streptococcus thermophilus Time Factors GRAM-POSITIVE BACTERIA Transcription Genetic education OLIGOPEPTIDE TRANSPORT Biological Transport Active ENTEROCOCCUS-FAECALIS Sigma Factor Bacillus subtilis Oligopeptide transport NATURAL GENETIC-TRANSFORMATION Microbiology BACILLUS-SUBTILIS 03 medical and health sciences Bacterial Proteins Sigma factor Tandem Mass Spectrometry Extracellular Transcriptional regulation LACTOCOCCUS-LACTIS Luciferases Molecular Biology 030304 developmental biology 0303 health sciences SEX-PHEROMONE biology IDENTIFICATION 030306 microbiology DNA Transformation Competence Cell Membrane Natural competence Quorum Sensing Membrane Proteins Articles Gene Expression Regulation Bacterial biology.organism_classification Biochemistry Mutation REGULATOR CHEMICALLY-DEFINED MEDIUM Chromatography Liquid |
| Zdroj: | Journal of bacteriology, Vol. 195, no.8, p. 1845-55 (2013) Journal of Bacteriology Journal of Bacteriology, American Society for Microbiology, 2013, 195 (8), pp.1845-1855. ⟨10.1128/JB.02196-12⟩ |
| ISSN: | 0021-9193 1098-5530 |
| Popis: | In streptococci, ComX is the alternative sigma factor controlling the transcription of the genes encoding the genetic transformation machinery. In Streptococcus thermophilus , comX transcription is controlled by a complex consisting of a transcriptional regulator of the Rgg family, ComR, and a signaling peptide, ComS, which controls ComR activity. Following its initial production, ComS is processed, secreted, and imported back into the cell by the Ami oligopeptide transporter. We characterized these steps and the partners interacting with ComS during its extracellular circuit in more detail. We identified the mature form of ComS and demonstrated the involvement of the membrane protease Eep in ComS processing. We found that ComS was secreted but probably not released into the extracellular medium. Natural competence was first discovered in a chemically defined medium without peptides. We show here that the presence of a high concentration of nutritional peptides in the medium prevents the triggering of competence. In milk, the ecological niche of S. thermophilus , competence was found to be functional, suggesting that the concentration of nutritional peptides was too low to interfere with ComR activation. The kinetics of expression of the comS , comR , and comX genes and of a late competence gene, dprA , in cultures inoculated at different initial densities revealed that the activation mechanism of ComR by ComS is more a timing device than a quorum-sensing mechanism sensu stricto. We concluded that the ComS extracellular circuit facilitates tight control over the triggering of competence in S. thermophilus . |
| Databáze: | OpenAIRE |
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