Past, Present, and Future of Extracytoplasmic Function σ Factors: Distribution and Regulatory Diversity of the Third Pillar of Bacterial Signal Transduction

Publikation: Beitrag in FachzeitschriftÜbersichtsartikel (Review)BeigetragenBegutachtung



Responding to environmental cues is a prerequisite for survival in the microbial world. Extracytoplasmic function σ factors (ECFs) represent the third most abundant and by far the most diverse type of bacterial signal transduction. While archetypal ECFs are controlled by cognate anti-σ factors, comprehensive comparative genomics efforts have revealed a much higher abundance and regulatory diversity of ECF regulation than previously appreciated. They have also uncovered a diverse range of anti-σ factor-independent modes of controlling ECF activity, including fused regulatory domains and phosphorylation-dependent mechanisms. While our understanding of ECF diversity is comprehensive for well-represented and heavily studied bacterial phyla-such as Proteobacteria, Firmicutes, and Actinobacteria (phylum Actinomycetota)-our current knowledge about ECF-dependent signaling in the vast majority of underrepresented phyla is still far from complete. In particular, the dramatic extension of bacterial diversity in the course of metagenomic studies represents both a new challenge and an opportunity in expanding the world of ECF-dependent signal transduction. Expected final online publication date for the Annual Review of Microbiology, Volume 77 is September 2023. Please see for revised estimates.


Seiten (von - bis)625-644
FachzeitschriftAnnual review of microbiology
Frühes Online-Datum12 Juli 2023
PublikationsstatusVeröffentlicht - 15 Sept. 2023

Externe IDs

Scopus 85171599898
WOS 001066051900031


ASJC Scopus Sachgebiete


  • Bacteria/genetics, Bacterial Proteins/genetics, Gene Expression Regulation, Bacterial, Sigma Factor/genetics, Signal Transduction, Signal transduction, Gene regulation, Comparative genomics, Sigma factor, Stress response, Transcription initiation