Enterococcal sex pheromones: signaling, social behavior, and evolution.

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Conjugative plasmids in Enterococcus faecalis mediate the spread of antibiotic resistance and virulence factors.
• Lateral gene transfer, crucial for bacterial adaptation, is often regulated by specific environmental cues.

Purpose of the Study:

• To elucidate the regulatory mechanisms of pheromone-induced plasmid transfer using the tetracycline-resistance plasmid pCF10.
• To understand the role of inhibitor peptides in controlling conjugation and maintaining system homeostasis.

Main Methods:

• Analysis of pheromone-responsive regulatory networks in Enterococcus faecalis.
• Investigation of transcriptional and posttranscriptional control mechanisms governing plasmid transfer.
• Characterization of the bi-stable biological switch behavior.

Main Results:

• Pheromone-induced conjugation is tightly regulated by a plasmid-encoded inhibitor peptide.
• The system exhibits complex multi-layered regulation, including transcriptional and posttranscriptional control.
• A bi-stable biological switch mechanism ensures precise control over plasmid transfer.

Conclusions:

• The pheromone-inducible conjugation system in Enterococcus faecalis is a highly regulated process essential for efficient plasmid transfer.
• Tight regulation minimizes the fitness cost associated with plasmid maintenance in host cells.
• This model system provides insights into conserved mechanisms of plasmid-mediated gene transfer in bacteria.