Abstract
Bacteria possess the ability to adapt to changing environments. To enable this, cells use reversible post-translational modifications on key proteins to modulate their behavior, metabolism, defense mechanisms and adaptation of bacteria to stress. In this review, we focus on bacterial protein switches that are activated during exposure to oxidative stress. Such protein switches are triggered by either exogenous reactive oxygen species (ROS) or endogenous ROS generated as by-products of the aerobic lifestyle. Both thiol switches and metal centers have been shown to be the primary targets of ROS. Cells take advantage of such reactivity to use these reactive sites as redox sensors to detect and combat oxidative stress conditions. This in turn may induce expression of genes involved in antioxidant strategies and thus protect the proteome against stress conditions. We further describe the well-characterized mechanism of selected proteins that are regulated by redox switches. We highlight the diversity of mechanisms and functions (as well as common features) across different switches, while also presenting integrative methodologies used in discovering new members of this family. Finally, we point to future challenges in this field, both in uncovering new types of switches, as well as defining novel additional functions.
Highlights
Most bacterial cells live in a dynamically fluctuating environment, requiring rapid responses to enable successful growth
One of the main strategies of this defense system is to utilize rapid and reversible oxidation-dependent modification of specific protein thiol residues, serving as redox-sensitive switches of the defense proteins and mediating their rapid activation (Ilbert et al, 2006; Cremers and Jakob, 2013). Another strategy – which can be coupled to modification of the thiol groups – is exploiting redox properties of metal centers to regulate proteins during fluctuating oxidant levels
One of the main classes of thiol switches in bacteria are thioredoxin and glutaredoxin enzymes that restore the redox status of proteins using reduction-oxidation cycles of their conserved catalytic cysteine residues with the help of cellular cofactors, such as NADH, NADPH, and Glutathione (Holmgren et al, 2005; López-Grueso et al, 2019)
Summary
Most bacterial cells live in a dynamically fluctuating environment, requiring rapid responses to enable successful growth. One of the main strategies of this defense system is to utilize rapid and reversible oxidation-dependent modification of specific protein thiol residues, serving as redox-sensitive switches of the defense proteins and mediating their rapid activation (Ilbert et al, 2006; Cremers and Jakob, 2013).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
