Cysteine Proteome Reveals Response to Endogenous Oxidative Stress in Bacillus cereus.

Fella Hamitouche,Jean Armengaud,Catherine Duport,Luc Dedieu

doi:10.3390/ijms22147550

Abstract

At the end of exponential growth, aerobic bacteria have to cope with the accumulation of endogenous reactive oxygen species (ROS). One of the main targets of these ROS is cysteine residues in proteins. This study uses liquid chromatography coupled to high-resolution tandem mass spectrometry to detect significant changes in protein abundance and thiol status for cysteine-containing proteins from Bacillus cereus during aerobic exponential growth. The proteomic profiles of cultures at early-, middle-, and late-exponential growth phases reveals that (i) enrichment in proteins dedicated to fighting ROS as growth progressed, (ii) a decrease in both overall proteome cysteine content and thiol proteome redox status, and (iii) changes to the reduced thiol status of some key proteins, such as the transition state transcriptional regulator AbrB. Taken together, our data indicate that growth under oxic conditions requires increased allocation of protein resources to attenuate the negative effects of ROS. Our data also provide a strong basis to understand the response mechanisms used by B. cereus to deal with endogenous oxidative stress.

Highlights

For aerobic bacteria, oxygen (O2) is an essential element that acts as the final acceptor in respiratory chain electron transport to efficiently produce energy [1]
Our results revealed that B. cereus adjusts its proteome both at the protein and cysteine residue levels to deal with reactive oxygen species (ROS), which accumulates over time during aerobic growth
Aerobic bacteria must deal with endogenous ROS, which are mainly generated as byproducts of respiratory metabolism

Summary

Introduction

Oxygen (O2) is an essential element that acts as the final acceptor in respiratory chain electron transport to efficiently produce energy [1]. The most extensively characterized LMW thiol is glutathione (GSH), which is found in eukaryotes and gram negative bacteria [9]; gram positive bacteria use alternative LMW thiols, such as bacillithiol (BSH) and mycothiol (MSH) [9]

Methods

Results

Conclusion