Related Experiment Videos
Cell growth and lambda phage development controlled by the same essential Escherichia coli gene, ftsH/hflB
C Herman1, T Ogura, T Tomoyasu
1Institut Jacques Monod (Centre National de la Recherche Scientifique, Université Paris 7), France.
Summary
The FtsH/HflB protein in Escherichia coli significantly impacts lambda phage lysogeny. This protein, an essential inner membrane component, influences the phage
Area of Science:
- Microbiology
- Molecular Biology
- Bacteriology
Background:
- Bacteriophage lambda's life cycle involves a critical choice between lysis and lysogeny.
- This decision is regulated by host cell factors in Escherichia coli.
- The stability of the phage cII protein is a key determinant of lysogeny.
Purpose of the Study:
- To investigate the role of the ftsH gene in the lambda phage lysogenic pathway.
- To elucidate the relationship between FtsH/HflB and other host factors controlling lysogeny, such as HflA.
Main Methods:
- Utilized a temperature-sensitive ftsH1 mutant of Escherichia coli.
- Assessed the frequency of lambda lysogenization in wild-type and mutant strains.
- Examined the effect of FtsH/HflB overproduction in an hflA null mutant.
- Investigated suppressor mutations in the fur gene.
Main Results:
- The frequency of lambda lysogenization was significantly increased in the ftsH1 mutant.
- The ftsH gene, encoding FtsH/HflB, is identical to hflB, a known regulator of cII stability.
- FtsH/HflB's control over lysogeny is independent of the HflA protease.
- Overproduction of FtsH/HflB reversed the high lysogenization frequency in hflA mutants.
- FtsH/HflB stimulates cII degradation.
Conclusions:
- FtsH/HflB plays a crucial role in regulating the lambda phage lysogenic decision.
- FtsH/HflB may act in an HflA-independent proteolytic pathway or as a chaperone to promote cII degradation.
- The fur gene mutations do not restore FtsH/HflB function in lambda lysogenization.