Related Experiment Video
Updated: Apr 26, 2026
12:29
Population and Single-Cell Analysis of Antibiotic Persistence in Escherichia coli
Published on: March 24, 2023
4.6K
Toxin YafQ increases persister cell formation by reducing indole signalling
Ying Hu1, Brian W Kwan, Devon O Osbourne
1Department of Chemical Engineering and, Pennsylvania State University, University Park, PA, 16802-4400, USA.
Environmental Microbiology
|July 22, 2014
Summary
Toxin YafQ from Escherichia coli toxin/antitoxin systems increases persister cell formation by cleaving specific mRNA transcripts. This toxin reduces indole levels, a key factor in bacterial stress survival.
Area of Science:
- Microbiology
- Bacterial Physiology
- Molecular Biology
Background:
- Persister cells are crucial for bacterial survival under antibiotic stress by entering a dormant state.
- Toxin/antitoxin (TA) systems are implicated in persister cell formation, but the exact mechanisms are not fully understood.
Purpose of the Study:
- To investigate the role of YafQ, a toxin from the YafQ/DinJ TA system in Escherichia coli, in persister cell formation.
- To elucidate the molecular mechanisms by which YafQ influences bacterial stress resistance.
Main Methods:
- Assessing persister cell formation in the presence of YafQ under various antibiotic stresses.
- Analyzing changes in protein and mRNA expression, specifically targeting tryptophanase (TnaA) and RpoS.
- Measuring indole levels and evaluating the impact of indole manipulation on persistence.
Main Results:
- YafQ production significantly increased persister cell formation across multiple antibiotics.
- YafQ reduced tryptophanase (TnaA) and stationary-phase sigma factor RpoS levels by cleaving their respective mRNAs.
- Reduced indole production, a downstream effect of YafQ activity, was directly correlated with increased persistence.
Conclusions:
- YafQ enhances bacterial persistence by downregulating indole synthesis through TnaA and RpoS.
- This study highlights a novel link between TA systems, metabolic regulation, and bacterial stress survival.
- YafQ's mechanism provides insights into bacterial cell signaling and antibiotic resistance strategies.
More Related Videos
08:51Applying an Inducible Expression System to Study Interference of Bacterial Virulence Factors with Intracellular Signaling
Published on: June 25, 2015
8.7K
09:21Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L.
Published on: February 15, 2019
9.5K
Related Concept Videos
01:28Gene Regulation in Microbial Communities: Quorum Sensing
944
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
944
01:12Bacterial Toxins
132
Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
132
01:30Bacterial Signaling
29.5K
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
29.5K
01:17Gene Regulation During Sporulation
707
Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...
707
01:28Regulation of Bacterial Virulence
70
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
70
01:23Stringent Response in E. coli
520
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
520