Regulatory pathways governing the transition to stationary phase in Bacillus subtilis

Allison Virginia Banse

Bacteria enter stationary phase when they exhaust the nutrients available to them, or when other adverse environmental changes occur. The transition to stationary phase requires dramatic changes in gene expression in which suites of genes are turned on that allow the cells to adapt to unfavorable circumstances. These changes in gene expression are governed by signal transduction pathways that sense the onset of adverse conditions and respond by activating (or inactivating) global regulatory proteins. One such global regulator is the alternate sigma factor σ S , which governs the transition to stationary phase in Escherichia coli. In the spore forming bacterium Bacillus subtilis, the subject of this work, the transition to stationary phase is governed in large part by the master regulator of sporulation, Spo0A∼P, and the AbrB repressor. The AbrB protein is a repressor of numerous genes...