A Stringent Analysis of Polyphosphate Dynamics in Escherichia coli

Abstract

During stress, bacterial cells activate a conserved pathway called the stringent response that promotes survival. Polyphosphates are long chains of inorganic phosphates that modulate this response in diverse bacterial species. In this issue, Michael J. Gray provides an important correction to the model of how polyphosphate accumulation is regulated during the stringent response in Escherichia coli (M. J. Gray, J. Bacteriol, 201:e00664-18, 2019, https://doi.org/10.1128/JB.00664-18). With other recent publications, this study provides a revised framework for understanding how bacterial polyphosphate dynamics might be exploited in infection control and industrial applications.

Quantitative physiology and proteome adaptations of Bifidobacterium breve NRBB57 at near-zero growth rates

“…Moreover, proteomics results also showed the up-regulation of polyphosphate kinase at lower growth rates, this enzyme is involved in the production and accumulation of inorganic polyphosphates. Thereby, the stringent response inhibits exopolyphosphatase and triggers the activity of the polyphosphate kinase and subsequent accumulation of polyphosphate (37, 38). Polyphosphate accumulates in response to nutrient starvation as seen in the retentostat cells, and plays an important role in the stress response interacting in several important cellular processes that include inhibiting reinitiation of DNA replication and promoting fitness during starvation (39, 40).…”

“…Moreover, proteomics results also showed the up-regulation of polyphosphate kinase at lower growth rates, this enzyme is involved in the production and accumulation of inorganic polyphosphates. Thereby, the stringent response inhibits exopolyphosphatase and triggers the activity of the polyphosphate kinase and subsequent accumulation of polyphosphate (37,38).…”

Effects of Polyphosphate metabolism Mutations on Biofilm, Capsule Formation and Virulence Traits in Hypervirulent ST23Klebsiella pneumoniaeSGH10

“…The classical model proposed by A. Kornberg’s group for E. coli suggests that a stress response such as amino acid starvation leads to the accumulation of (p)ppGpp, which interacts with PPX and inhibits it, promoting polyP accumulation. However, based on recent evidence, other factors such as DksA and GreA proteins significantly regulate polyP accumulation in response to amino acid starvation 49,50 . This could explain our observations in the Δ ppx mutant.…”

Microbial musings – Summer 2022

“…Gray at the University of Alabama at Birmingham, USA, look further into this question [25]. Gray’s group has done much to place polyP within the larger picture of cellular physiology and regulation, specifically the stringent response, which was nicely summarized recently by Michael Downey (@DowneyUOttawa) at the University of Ottawa, Canada [26]. Rapidly growing E.…”

“…Gray at the University of Alabama at Birmingham, USA, look further into this question [25]. Gray's group has done much to place polyP within the larger picture of cellular physiology and regulation, specifically the stringent response, which was nicely summarized recently by Michael Downey (@DowneyUOttawa) at the University of Ottawa, Canada [26]. Rapidly growing E. coli in rich media have undetectable levels of polyP, as the phosphate is needed for de novo nucleotide and phospholipid biosynthesis, but as soon as the growth rates drop, through one of many different stresses or nutrient limitations, the available phosphate is rapid stored through conversion to polyP.…”