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Updated: Jun 2, 2026
Live-Cell Fluorescence Microscopy to Investigate Subcellular Protein Localization and Cell Morphology Changes in Bacteria
Published on: November 23, 2019
Maf acts downstream of ComGA to arrest cell division in competent cells of B. subtilis
Kenneth Briley1, Peter Prepiak, Miguel J Dias
1Department of Microbiology and Molecular Genetics, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA.
Abstract:
Transformable (competent) cells of Bacillus subtilis are blocked in cell division because the traffic ATPase ComGA prevents the formation of FtsZ rings. Although ComGA-deficient cells elongate and form FtsZ rings, cell division remains blocked at a later stage and the cells become mildly filamented. Here we show that the highly conserved protein Maf is synthesized predominantly in competent cells under the direct control of the transcription factor ComK and is solely responsible for the later block in cell division. In vivo and in vitro data show that Maf binds to both ComGA and DivIVA. A point mutation in maf that interferes with Maf binding to DivIVA also interferes with the ability of Maf to inhibit cell division. Based on these findings, we propose that Maf and ComGA mediate mechanisms for the inhibition of cell division in competent cells with Maf acting downstream of ComGA. We further suggest that Maf must interact with DivIVA to inhibit cell division.
Insights
The protein Maf inhibits Bacillus subtilis cell division in competent cells, acting downstream of ComGA and requiring interaction with DivIVA for this function.
Area of Science:
- Microbiology
- Cell Biology
- Molecular Biology
Background:
- Bacillus subtilis competent cells exhibit blocked cell division, initially attributed to the traffic ATPase ComGA preventing FtsZ ring formation.
- ComGA-deficient cells show later-stage division blocks and mild filamentation, suggesting additional inhibitory mechanisms.
Purpose of the Study:
- To identify the factor responsible for the later-stage cell division block in Bacillus subtilis competent cells.
- To elucidate the mechanism by which Maf inhibits cell division in competent Bacillus subtilis.
Main Methods:
- Analysis of Maf protein synthesis under ComK control in competent cells.
- In vivo and in vitro binding assays to determine interactions between Maf, ComGA, and DivIVA.
- Functional analysis of a maf point mutation affecting DivIVA binding on cell division inhibition.
Main Results:
- The conserved protein Maf is synthesized in competent cells, controlled by ComK, and is responsible for the later cell division block.
- Maf directly binds to both ComGA and DivIVA.
- A maf mutation disrupting DivIVA binding abolishes Maf's cell division inhibitory function.
Conclusions:
- Maf acts downstream of ComGA to inhibit cell division in competent Bacillus subtilis.
- Maf requires interaction with DivIVA to mediate cell division inhibition.
- These findings reveal a two-step mechanism for cell division inhibition during competence in Bacillus subtilis.
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