Skip to main page content
U.S. flag
See More

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2010 Jan 15;5(1):47-62.
doi: 10.1021/cb900258z.

Orchestrating redox signaling networks through regulatory cysteine switches

Candice E Paulsen  1 , Kate S Carroll
Affiliations
Review

Orchestrating redox signaling networks through regulatory cysteine switches

Candice E Paulsen et al. ACS Chem Biol. .

Abstract

Hydrogen peroxide (H(2)O(2)) acts as a second messenger that can mediate intracellular signal transduction via chemoselective oxidation of cysteine residues in signaling proteins. This Review presents current mechanistic insights into signal-mediated H(2)O(2) production and highlights recent advances in methods to detect reactive oxygen species (ROS) and cysteine oxidation both in vitro and in cells. Selected examples from the recent literature are used to illustrate the diverse mechanisms by which H(2)O(2) can regulate protein function. The continued development of methods to detect and quantify discrete cysteine oxoforms should further our mechanistic understanding of redox regulation of protein function and may lead to the development of new therapeutic strategies.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Signaling-derived sources of intracellular reactive oxygen species (ROS). a) p66Shc generates pro-apoptotic ROS in the mitochondria. In response to oxidative stress, UV irradiation, or growth factor deprivation, p66Shc localizes to the mitochondria where it generates ROS (O2•− or H2O2). H2O2 ultimately produced can diffuse across the outer mitochondrial membrane to the cytosol where it can modulate the activity of diverse proteins. P66Shc-derived H2O2 also stimulates the opening of the permeability transition pore causing mitochondrial swelling and apoptosis. b) NOX enzymes assemble at discrete locations in the cell such as the plasma membrane and at focal adhesions to generate ROS in response to diverse extracellular signals. The catalytic subunit of each NOX isoform (NOX1-5, DUOX1-2) has a conserved domain structure of six transmembrane α-helices and binding sites for two heme prosthetic groups. The C-terminal intracellular domain binds the FAD and NADPH cofactors and electrons from NADPH are translocated across the membrane through the heme prosthetic groups to generate O2•− (NOX1-5) or H2O2 (DUOX1-2). Full enzymatic activity of these enzymes requires the association of co-activator proteins (NOX1-4) or Ca2+ (NOX5, DUOX1-2) to the N-terminal intracellular domain. The O2•− produced is dismutated by SOD to H2O2, which can freely diffuse across the membrane to the cytosol to regulate protein activity and signaling cascades.
Figure 2
Figure 2
Oxidative modifications of protein cysteine residues. Low pKa cysteines are present in the cell as thiolates and form a sulfenic acid (SOH) upon reaction with H2O2. Once formed, the SOH can react with a second cysteine either in the same or a second protein yields a disulfide. Alternatively, a SOH can react with the low molecular weight thiol glutathione (GSH) (pink circle) to form a special disulfide known as S-glutathiolation. In the event that a neighboring cysteine or glutathione are absent, the amide nitrogen of the neighboring residue can attack the SOH to form a sulfenamide. Each of these oxoforms can be reduced by the GSH/glutathione reductase or thioredoxin/thioredoxin reductase systems to regenerate the thiols (not depicted). The SOH can also further react with H2O2 to generate the irreversible SO2H and SO3H oxoforms.
Figure 3
Figure 3
Model for redox-regulation of cardiac hypertrophy by HDAC4. The type-II histone deacetylase, HDAC4 normally modifies histones to repress the expression of genes involved in hypertrophy. Nuclear localization of HDAC4 is mediated by its association with importin α (Imp) through a multiprotein complex consisting of the molecular chaperone DnaJb5, TBP-2, and Trx1. In the presence of H2O2, intramolecular disulfide bonds form within HDCA4 and DnaJb5, which stimulates dissociation and nuclear export of the complex. Upon removal of H2O2, Trx1 reduces the disulfides in both HDAC4 and DnaJb5 to restore formation and nuclear localization of the complex.
Figure 4
Figure 4
Detection and characterization of oxidized proteins. a) Structures and reaction scheme for chemoselective tools used to detect protein SOH in vitro and in vivo. b) Flowchart of steps that can be undertaken and the corresponding information obtained to elucidate the significance and prevalence of protein oxidation in vivo.
Figure 5
Figure 5
Redox-regulation of protein complexes influences gene transcription and signaling cascades. a) Proposed mechanism for redox-regulation of NRF2 stability and activity by KEAP1 and p21CIP1/WAF1. Binding of KEAP1 to the DLG and ETGE sites in NRF2 optimally orients lysine residues in NRF2 for ubiquitination (black circles) leading to degradation. In the presence of H2O2, three cysteine residues in KEAP1 are oxidatively modified (oxoform unknown, S*), which induces a conformational change in KEAP1 that decreases its affinity for the DLG site. Additionally, KEAP1 oxidation may mask its NES leading to nuclear accumulation of the complex and activation of NRF2. p21CIP1/WAF1 can compete with oxidized KEAP1 for binding to the NRF2 DLG site to enhance the stability of the transcription factor. b) Two proposed models for H2O2-mediated activation of ASK1. ASK1 assembles into multimers in the cell that interact with Trx1. Association of Trx1 with ASK1 sequesters the kinase in an inactive conformation. Upon oxidation of Trx1 by H2O2, ASK1 is released to interact with additional proteins forming the active signaling complex (Trx1-oxidation model). Alternatively, H2O2 induces intermolecular disulfide bond formation between ASK1 monomers to facilitate the interaction with additional proteins forming the activate kinase complex (ASK1-oxidation model). In this second model, Trx1 negatively regulates ASK1 by maintaining the kinase in a reduced and inactivate state.
See this image and copyright information in PMC

References

    1. Andersen JK. Oxidative stress in neurodegeneration: cause or consequence? Nat. Med. 2004;10(Suppl):S18–S25. - PubMed
    1. Klaunig JE, Kamendulis LM. The role of oxidative stress in carcinogenesis. Annu. Rev. Pharmacol. Toxicol. 2004;44:239–267. - PubMed
    1. Lowell BB, Shulman GI. Mitochondrial dysfunction and type 2 diabetes. Science. 2005;307:384–387. - PubMed
    1. Reddie KG, Carroll KS. Expanding the functional diversity of proteins through cysteine oxidation. Curr. Opin. Chem. Biol. 2008;12:746–754. - PubMed
    1. Mumbengegwi DR, Li Q, Li C, Bear CE, Engelhardt JF. Evidence for a superoxide permeability pathway in endosomal membranes. Mol. Cell. Biol. 2008;28:3700–3712. - PMC - PubMed

Publication types