{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/30068"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/30068","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Regulation and production of extracellular signaling molecules in Bacillus subtilis","abstract":"Many bacteria use chemical signals for intercellular communication. These signals accumulate extracellularly and are sensed at threshold concentrations to alter gene expression. Bacillus subtilis uses cell-cell signals to control genetic competence, sporulation, degradative enzyme production and antibiotic synthesis. A family of peptide signals controls gene expression in B. subtilis by regulating transcription factors. I showed that the transcription of these peptide regulators is in turn controlled in part by the alternate sigma factor sigma-H. The activity of sigma-H is stimulated by nutrient starvation I determined that B. subtilis produces a putative interspecies signaling activity, AI-2, that depends on the conserved protein LuxS. To determine the effect of luxS on regulation of transcription in B. subtilis, I performed experiments to compare the transcriptional profiles of B. subtilis when luxS was deleted or overexpressed. I found no significant change in transcriptional profiles, indicating that B. subtilis does not use luxS/AI-2 for signaling under these conditions.","abstract_html":"Many bacteria use chemical signals for intercellular communication. These signals accumulate extracellularly and are sensed at threshold concentrations to alter gene expression. Bacillus subtilis uses cell-cell signals to control genetic competence, sporulation, degradative enzyme production and antibiotic synthesis. A family of peptide signals controls gene expression in B. subtilis by regulating transcription factors. I showed that the transcription of these peptide regulators is in turn controlled in part by the alternate sigma factor sigma-H. The activity of sigma-H is stimulated by nutrient starvation I determined that B. subtilis produces a putative interspecies signaling activity, AI-2, that depends on the conserved protein LuxS. To determine the effect of luxS on regulation of transcription in B. subtilis, I performed experiments to compare the transcriptional profiles of B. subtilis when luxS was deleted or overexpressed. I found no significant change in transcriptional profiles, indicating that B. subtilis does not use luxS/AI-2 for signaling under these conditions.","abstract_has_math":false,"creators":["McQuade, Ryan S. (Ryan Scott), 1975-"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Biology.","school":null,"contributors":[],"advisors":["Alan D. 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A family of peptide signals controls gene expression in B. subtilis by regulating transcription factors. I showed that the transcription of these peptide regulators is in turn controlled in part by the alternate sigma factor sigma-H. The activity of sigma-H is stimulated by nutrient starvation I determined that B. subtilis produces a putative interspecies signaling activity, AI-2, that depends on the conserved protein LuxS. To determine the effect of luxS on regulation of transcription in B. subtilis, I performed experiments to compare the transcriptional profiles of B. subtilis when luxS was deleted or overexpressed. I found no significant change in transcriptional profiles, indicating that B. subtilis does not use luxS/AI-2 for signaling under these conditions."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Regulation and production of extracellular signaling molecules in Bacillus subtilis"]}]}],"canonical_facts":{"dc:contributor.advisor":["Alan D. Grossman."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Biology."],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Biology."],"dc:creator":["McQuade, Ryan S. (Ryan Scott), 1975-"],"dc:date.accessioned":["2006-03-24T18:16:37Z"],"dc:date.available":["2006-03-24T18:16:37Z"],"dc:date.issued":["2004"],"dc:description":["Thesis (Ph. 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To determine the effect of luxS on regulation of transcription in B. subtilis, I performed experiments to compare the transcriptional profiles of B. subtilis when luxS was deleted or overexpressed. I found no significant change in transcriptional profiles, indicating that B. subtilis does not use luxS/AI-2 for signaling under these conditions."],"dc:description.degree":["Ph.D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/1721.1/30068"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. 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