sigma B-dependent regulation of gsiB in response to multiple stimuli in Bacillus subtilis.

The expression of thegsiB gene ofBacillus subtilis in response to a wide variety of stress conditions was analysed, and the results provide evidence thatgsiB is subject to a σB regulation. Primer extension experiments established identical start points forgsiB transcription during growth and after the induction by heat shock, salt or ethanol stress, and glucose limitation. The sequence upstream of the transcription start point shows great similarity to the sequences of σB promoters ofB. subtilis. σB was absolutely required for the increase ingsiB mRNA level and in the synthesis rate of GsiB in response to various stimuli. Measurements of the ATP pool indicated that changes in the level of ATP might be one of the signals that regulate the activity of σB inB. subtilis.