title: Novel modulators controlling entry into sporulation in Bacillus subtilis.
abstract: Upon nutrient deprivation, Bacillus subtilis initiates the developmental process of sporulation by integrating environmental and extracellular signals. These signals are channeled into a phosphorelay ultimately activating the key transcriptional regulator of sporulation, Spo0A. Subsequently, phosphorylated Spo0A regulates the expression of genes required for sporulation to initiate. Here we identified a group of genes whose transcription levels are controlled by Spo0A during exponential growth. Among them, three upregulated genes, termed sivA, sivB (bslA), and sivC, encode factors found to inhibit Spo0A activation. We furthermore show that the Siv factors operate by reducing the activity of histidine kinases located at the top of the sporulation phosphorelay, thereby decreasing Spo0A phosphorylation. Thus, we demonstrate the existence of modulators, positively controlled by Spo0A, which inhibit inappropriate entry into the costly process of sporulation, when conditions are favorable for exponential growth.
authors: Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors: Sharon
authors: S
authors: Garti-Levi
authors: Ashlee
authors: A
authors: Eswara
authors: Yoav
authors: Y
authors: Smith
authors: Masaya
authors: M
authors: Fujita
authors: Sigal
authors: S
authors: Ben-Yehuda
mesh_terms: D001412:Bacillus subtilis / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D001426:Bacterial Proteins / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction; D013171:Spores, Bacterial / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; C080950:Spo0A protein, Bacillus subtilis; D014157:Transcription Factors; D011494:Protein Kinases; D000071677:Histidine Kinase