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Cell-cell signaling pathway activating a developmental transcription factor in Bacillus subtilis
J A Londoño-Vallejo1, P Stragier
1Institut de Biologie Physico-Chimique, Paris, France.
Genes & Development
|February 15, 1995
Summary
A novel protein, CsfX, acts as a signal from the forespore to the mother cell, activating pro-sigma E processing during Bacillus subtilis sporulation. This finding clarifies a key regulatory step in bacterial development.
Area of Science:
- Microbiology
- Molecular Biology
- Bacterial Genetics
Background:
- During Bacillus subtilis sporulation, transcription is regulated by sigma factors.
- Sigma E (σE) is synthesized as an inactive precursor (pro-σE) in the mother cell.
- Sigma F (σF) in the forespore controls genes essential for activating pro-σE.
Purpose of the Study:
- To identify and characterize the gene responsible for triggering pro-σE processing.
- To elucidate the mechanism of signal transduction from the forespore to the mother cell.
Main Methods:
- Genetic analysis of Bacillus subtilis sporulation mutants.
- Gene identification and protein characterization (including signal sequence analysis).
- Functional studies of the identified gene product.
Main Results:
- Identified and characterized the sigma F-dependent gene, csfX.
- Demonstrated that the CsfX protein is necessary and sufficient for pro-σE processing.
- The CsfX protein possesses a signal sequence, suggesting extracellular or trans-septal activity.
Conclusions:
- CsfX mediates the activation signal for pro-σE processing from the forespore to the mother cell.
- The CsfX protein likely acts on a membrane-bound enzyme in the mother cell to trigger pro-σE maturation.
- This discovery reveals a novel intercellular communication pathway in bacterial sporulation.
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