Related Experiment Video
Updated: Mar 7, 2026
07:16
Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation
Published on: June 21, 2021
2.3K
Simultaneous Activation of Iron- and Thiol-Based Sensor-Regulator Systems by Redox-Active Compounds
Kang-Lok Lee1, Ji-Sun Yoo1, Gyeong-Seok Oh1
1School of Biological Sciences and Institute of Microbiology, Seoul National University Seoul, South Korea.
Frontiers in Microbiology
|February 18, 2017
Summary
This study monitored multiple bacterial stress response pathways to reveal the diverse chemical activities of reactive compounds. This approach uncovers novel compound effects and provides a comprehensive understanding of cellular responses to oxidative and electrophilic stress.
Area of Science:
- Microbiology and Molecular Biology
- Biochemistry and Chemical Biology
Background:
- Bacteria encounter diverse redox-active compounds (RACs) in natural environments, including reactive oxygen species (ROS) and reactive electrophile species (RES).
- These compounds induce cellular stress by oxidizing or alkylating thiols, modulating sensitive regulators and activating response pathways.
- Previous studies often focused on single regulatory pathways, limiting the understanding of a compound's multifaceted effects.
Purpose of the Study:
- To investigate the comprehensive chemical activities of representative RACs in the model actinobacterium *Streptomyces coelicolor*.
- To develop and apply a method for time-course monitoring of multiple sensitive regulatory pathways to predict compound activities.
- To reveal novel pathways of cellular regulation by reactive compounds.
Main Methods:
- Monitoring the activity of three key sensor-regulators: SoxR (senses RACs via [2Fe-2S] cluster oxidation), CatR/PerR (senses peroxides via iron binding), and RsrA (senses RES via disulfide formation).
- Time-course analysis of target transcript induction for each regulator in response to various RACs.
- Utilizing *Streptomyces coelicolor* as the model organism.
Main Results:
- Phenazine methosulfate (PMS) was identified as an effective RAC and ROS producer.
- *p*-Benzoquinone showed potent RAC, ROS-producing, and RES activities, notably inducing the RsrA-SigR system via cysteine thiol adducts.
- Plumbagin, diamide, and monobromobimane exhibited varying degrees of RAC, ROS-producing, and RES activities, with diamide being a potent RES.
Conclusions:
- Monitoring multiple regulator responses provides a comprehensive profile of a compound's chemical activities *in vivo*.
- The study revealed novel mechanisms of RsrA regulation by benzoquinone, highlighting its sensitivity to electrophilic modification.
- This integrated approach offers a powerful tool for characterizing the complex interactions between chemicals and cellular regulatory networks.
Related Concept Videos
01:27Redox Reactions
1.3K
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
1.3K
01:24Redox Reactions
59.2K
Oxidation-reduction or redox reactions involve the transfer of electrons from one molecule or atom to another. When an atom gains an electron, another atom must lose an electron, meaning oxidation and reduction must occur together. Since the redox occurs in pairs, the atom that gets oxidized is also called the reducing agent or reductant, and the atom that is reduced is also called the oxidizing agent or oxidant. A straightforward way to remember the definitions of oxidation and reduction is...
59.2K
01:28Global Regulatory Systems
811
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
811
01:20Sulfur Assimilation
456
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
456
01:26Redox Titration: Other Oxidizing and Reducing Agents
1.5K
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...
1.5K
01:30Other Stress Responses in Bacteria
482
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
482