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Updated: May 28, 2026
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A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
Stochastic pulse regulation in bacterial stress response
James C W Locke1, Jonathan W Young, Michelle Fontes
1Howard Hughes Medical Institute, Division of Biology and Bioengineering, Broad Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
Science (New York, N.Y.)
|October 8, 2011
Summary
Bacillus subtilis uses stochastic pulses to signal energy stress. This gene regulatory mechanism relies on an ultrasensitive switch, cellular noise, and feedback loops for precise stress response.
Area of Science:
- Microbiology
- Systems Biology
- Molecular Biology
Background:
- Gene regulatory circuits employ dynamic and stochastic strategies for environmental adaptation.
- The general stress response in prokaryotes is crucial for survival under adverse conditions.
Purpose of the Study:
- To investigate the activation dynamics of the general stress response mediated by sigma B (σ(B)) in individual Bacillus subtilis cells.
- To elucidate the molecular mechanisms underlying stochastic stress response signaling.
Main Methods:
- Single-cell analysis of Bacillus subtilis under energy stress.
- Perturbation and rewiring of the endogenous σ(B) regulatory circuit.
- Mathematical modeling to understand circuit dynamics.
Main Results:
- Energy stress triggers σ(B) activation in discrete, stochastic pulses.
- Increased stress levels correlate with higher pulse frequencies.
- The σ(B) circuit features an ultrasensitive phosphorylation switch, stochastic noise, and mixed transcriptional feedback.
Conclusions:
- Prokaryotes utilize stochastic pulse frequency modulation for signal encoding.
- A compact regulatory architecture enables dynamic stress response in Bacillus subtilis.
- The interplay of ultrasensitivity, noise, and feedback drives pulse generation and termination.
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