title: Stripping Bacillus: ComK auto-stimulation is responsible for the bistable response in competence development.
abstract: In Bacillus subtilis competence for genetic transformation develops only in a subpopulation of cells in an isogenic culture. The molecular mechanisms underlying this phenotypic heterogeneity are unknown. In this study, we stepwise simplify the signal transduction cascade leading to competence, yielding a strain devoid of all regulatory inputs for this process that have been identified so far. We demonstrate that auto-stimulation of ComK, the master regulator for competence development, is essential and in itself can be sufficient to generate a bistable expression pattern. We argue that transcriptional regulation determines the threshold of ComK to initiate the auto-stimulatory response, and that the basal level of ComK (in a wild-type strain governed by MecA-mediated proteolytic control) determines the fraction of cells that reach this threshold, and thus develop competence.
authors.affiliation: Groningen Biomolecular Sciences and Biotechnology Institute, Department of Genetics, University of Groningen, Kerklaan 30, 9751 NN Haren, the Netherlands.
authors.forename: Wiep Klaas
authors.initials: WK
authors.lastname: Smits
authors.forename: Caroline C
authors.initials: CC
authors.lastname: Eschevins
authors.forename: Kim A
authors.initials: KA
authors.lastname: Susanna
authors.forename: Sierd
authors.initials: S
authors.lastname: Bron
authors.forename: Oscar P
authors.initials: OP
authors.lastname: Kuipers
authors.forename: Leendert W
authors.initials: LW
authors.lastname: Hamoen
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D049071:Endopeptidase Clp / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006706:Homeostasis; D009154:Mutation; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014169:Transformation, Bacterial
chemical_list: D001426:Bacterial Proteins; C087481:ClpC protein, Bacteria; C093539:ComS protein, Bacillus subtilis; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D014157:Transcription Factors; C083616:mecA protein, Bacillus subtilis; C087449:comK protein, Bacillus subtilis; C483572:ClpP protease, E coli; D049071:Endopeptidase Clp