Regulation of inducible peroxide stress responses

Abstract

Summary Bacteria adapt to the presence of reactive oxygen species (ROS) by increasing the expression of detoxification enzymes and protein and DNA repair functions. These responses are co‐ordinated by transcription factors that regulate target genes in response to ROS. We compare three classes of peroxide‐sensing regulators: OxyR, PerR and OhrR. In all three cases, peroxides effect changes in the redox status of cysteine residues, but the molecular details are distinct. OxyR is converted into a transcriptional activator by the formation of a disulphide bond between two reactive cysteine residues. PerR is a metalloprotein that functions as a peroxide‐ sensitive repressor. Oxidation is modulated by metal ion composition and may also involve disulphide bond formation. OhrR represses an organic peroxide resistance protein and mediates derepression in response to organic peroxides. Peroxide sensing in this system requires a single conserved cysteine, which is oxidized to form a cysteine–sulphenic acid derivative.

Quorum-sensing agr mediates bacterial oxidation response via an intramolecular disulfide redox switch in the response regulator AgrA

“…This metabolic burden and the concomitant oxidative stress necessitate a delicate sensing system to enable the bacterium to avoid the detrimental effects caused by agr activation. Indeed, S. aureus, as a successful human pathogen, has developed a rapid adaptive response to a sublethal dose of oxidants (4,6), thereby reorienting gene expression for antioxidation. Our discovery suggests that the agr system serves to trigger bacterial response (through activation of bsaA gene in particular) to oxidative stress through an intracellular disulfide switch contained in the response regulator AgrA.…”

Sp1 and Sp3 Are Oxidative Stress-Inducible, Antideath Transcription Factors in Cortical Neurons

“…Adaptive responses to oxidative stress are most well defined in prokaryotic systems (Mongkolsuk and Helmann, 2002). Bacteria respond to toxic levels of ROS by increasing the expression of antioxidant and repair genes.…”

Control of bacterial iron homeostasis by manganese

“…The peroxide sensor PerR from B. subtilis senses H 2 O 2 through a bound Fe 2+ moiety that catalyzes the oxidation of a histidine residue to inactivate the protein and derepress the expression of genes needed to manage oxidative stress (10). PerR is much less sensitive to H 2 O 2 under low-iron conditions, when Mn 2+ occupies the regulatory metal site (11). Divalent iron and manganese share similar sizes and coordination geometries, but the total cellular iron content is in excess of manganese in E. coli cells (6,12).…”