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Synchronization of Caulobacter Crescentus for Investigation of the Bacterial Cell Cycle
Published on: April 8, 2015
CtrA mediates a DNA replication checkpoint that prevents cell division in Caulobacter crescentus
M Wortinger1, M J Sackett, Y V Brun
1Department of Biology and Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
The EMBO Journal
|September 6, 2000
Summary
The global regulator CtrA coordinates DNA replication and cell division in Caulobacter crescentus. Replication inhibition prevents CtrA synthesis, halting cell division and suggesting CtrA phosphorylation is affected by replication stress.
Area of Science:
- Microbiology
- Cell Biology
- Molecular Biology
Background:
- Cell division requires precise coordination with DNA replication to ensure genomic integrity.
- Caulobacter crescentus exhibits asymmetric cell division, producing distinct swarmer and stalked cell populations.
- The CtrA protein is a global regulator controlling DNA replication and cell division initiation.
Purpose of the Study:
- To investigate the role of CtrA in mediating a DNA replication checkpoint for cell division.
- To elucidate how CtrA regulates the expression of late cell division genes.
- To understand the impact of replication inhibition on CtrA synthesis and activity.
Main Methods:
- Analysis of CtrA regulation of ftsQ and ftsA gene transcription.
- Investigating CtrA synthesis and P(QA) promoter activity under replication inhibition.
- Examining the effect of replication inhibition on the CtrA P2 promoter and phosphorylation.
Main Results:
- CtrA activates the P(QA) promoter, co-transcribing ftsQA and regulating cell division protein expression order.
- Replication inhibition prevents CtrA synthesis in pre-divisional cells, blocking P(QA) transcription and cell division.
- Replication inhibition impedes activation of the CtrA P2 promoter, indicating CtrA phosphorylation may be replication-dependent.
Conclusions:
- CtrA acts as a crucial mediator of the DNA replication checkpoint, ensuring cell division only proceeds upon successful genome replication.
- The regulation of late cell division genes by CtrA is essential for ordered cell cycle progression.
- Replication stress impacts CtrA synthesis and phosphorylation, highlighting a feedback mechanism to maintain genomic stability.
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