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PapB Family Regulators as Master Switches of Fimbrial Expression
Fariba Akrami1,2, Hossein Jamali1,2, Mansoor Kodori3
1Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, 531 Boul des Prairies, Laval, QC H7V 1B7, Canada.
Microorganisms
|August 28, 2025
Summary
The transcriptional regulator PapB controls P fimbriae production, a key factor in bacterial infections. Understanding PapB-family proteins offers new strategies to prevent infections by targeting fimbrial adhesion.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Enterobacteriaceae possess fimbrial adhesins for host tissue colonization.
- P fimbriae, encoded by the pap operon, are critical virulence factors in urinary and systemic infections.
- PapB is a master transcriptional regulator of P fimbriae expression and influences other fimbrial systems.
Purpose of the Study:
- To review the structural organization, biogenesis, and regulatory control of P fimbriae.
- To emphasize the role of PapB and homologous regulatory proteins (SfaB, FocB, PixB, PefB).
- To explore the evolutionary conservation and regulatory mechanisms of PapB-family proteins.
Main Methods:
- Literature review of P fimbriae and PapB.
- Comparative genomics and phylogenetic analyses of PapB-family regulators.
- Discussion of regulatory responses to epigenetic changes, host signals, and global transcriptional cues.
Main Results:
- PapB family regulators are conserved across π-fimbrial systems and regulate diverse fimbriae.
- These regulators integrate various signals to control fimbrial production.
- PapB acts as a master switch for its own operon and influences heterologous fimbrial systems.
Conclusions:
- PapB-family proteins are crucial for dynamic bacterial adhesion in different environments.
- Understanding these regulators can lead to novel anti-adherence strategies.
- Targeting PapB-family proteins may prevent infections mediated by these fimbriae.
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