Cytosol ER Mitochondria

Thioredoxin systems in plants. From a 1988 slide based on Ref. 44. and animals cells. While known to occur in plants5,56,57 neither the cellular location nor the properties of the protein members of the plant system were known at the time. Our experiments showed that the participating thioredoxin was of a new type (designated thioredoxin h with its own properties37) that, as in bacterial and animal cells, was linked to the flavo-protein NADP-thioredoxin reductase (NTR).26,38,44 The...

Effects of Dinitrohalobenzenes by Interactions with Thioredoxin Reductase

L-chloro-2,4-dinitrobenzene (DNCB, CDNB) is an electrophilic compound used as a substrate in assays to determine glutathione S-transferases, being involved in elimination of DNCB in vivo.52 DNCB is therefore also used in cell culture experiments as a GSH-depleting agent.53 Furthermore, DNCB has an established use as an immunomodulatory agent to provoke delayed-type hypersensitivity reactions.54 Although proposed to function as a hapten, the mechanism of DNCB immunomodulation is however not...

Regulation of mRNA Translation and Stability in Iron Metabolism Is there a Redox Switch

Chemin des Bover esses 155, Swiss Institute for Experimental Cancer Research (ISREC), CH-1066 Epalinges, Switzerland Lukas.kuehn isrec.unil.ch Iron is both essential and potentially toxic for living organisms. Cellular iron homeostasis needs, therefore, to be maintained within an optimal concentration range by coordinate regulation of iron absorption, storage and utilization. In animals, this is achieved by post-transcriptional regulatory mechanisms that involve mRNA-protein interactions....

Cytoprotective Effects of Thioredoxin

Thioredoxin has been shown to play crucial roles in cytoprotection against a variety of oxidative stress. Recombinant thioredoxin can protect cells from anti-Fas antibody-induced apoptosis and cytotoxicity induced by TNF-alpha, hydrogen peroxide and activated neutrophils.1516 Thioredoxin is also a potent costimulator of various cytokine expression.17,18 Recently, Nilsson et al. reported that thioredoxin induces the secretion of TNF-alpha and maintains the expression of Bcl-2, whereby prolongs...

The Role of Thioredoxin and Glutaredoxin Systems in Disulfide Reduction and Thiol Redox Control

Department of Medical Biochemistry and Biophysics, Karolinska Institute, S-171 77, Stockholm, Sweden Arne.Holmgren mbb.ki.se Keywords Selenium, thioredoxin reductase, thioredoxin, glutaredoxin 1. Summary The intracellular redox environment in Escherichia coli and mammalian cells is reducing with a high level (1-10 mM) of the tripeptide thiol glutathione (GSH) and the proteins contain free sulfhydryl groups and disulfides are very rare. This is in contrast to the outer cell surface or the...

The Thioredoxin System

Thioredoxin reductase (TrxR) will reduce oxidized thioredoxin (Trx-S2) at the expense of NADPH Reaction (1) and reduced thioredoxin (Trx-(SH)2) is reoxidized by disulfides in proteins generating sulfhydryl groups Reaction (2) Trx-S2 + NADPH + H* - Trx-(SH)2 + NADP+ (1) Trx-(SH)2 + Protein-S2 - Trx-S2 + Protein-(SH)2. (2) The Km-value for Trx-S2 is typically from 1 to 3 pM. Thioredoxin is an efficient reductant with a low redox potential of - 270 mV.44 Today we know that there are some major...

Regulatory Disulfides Controlling Transcription Factor Activity in the Bacterial and Yeast Responses to Oxidative Stress

Wood, and Gisela Storz* Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892 *storz helix.nih.gov Keywords OxyR, RsrA, Yaplp, glutaredoxin, thioredoxin 1. Summary The ability of cells to modify their gene expression patterns in response to environmental changes is crucial to their survival and is largely dependent on the activities of specialized transcription factors....

References

Anfinsen CB, Haber E, Sela M, White FH. 1961. The kinetics of formation of native ribonuclease during oxidation of the reduced polypeptide chain. Proc. Natl. Acad. Sei. USA 47 1309-1314 2. Bader M, Muse DP, Ballou DP, Gassner C, Bardwell JCA. 1999. Oxidative protein folding is driven by the electron transport system. Cell 98 217-227 3. Bader MW, Hiniker A, Regeimbal J, Goldstone D, Haebel PW, Riemer J, Metealf P, Bardwell JCA. 2001. Turning a disulfide isomerase into an oxidase DsbC mutants...

Preface

Electron transfer between proteins is an essential cellular process. It underlies primary metabolic reactions such as in photosynthesis and respiratory oxidative phosphorylation. Recently, electron transfer reactions between specific proteins have also been found to play a key regulatory role in many fundamental cellular phenomena, including cell proliferation, regulation of specific gene expression, programmed cell death, and cell responses to oxygen levels, free radicals, and oxidants....

Oxidation

The pathway of glutathione biosynthesis in plants. Glutathione is synthesized in two steps, catalyzed by -glutamyl cysteine synthetase y-ECS and glutathione synthetase GS . The glutathione pool is maintained in the reduced form by the action of glutathione reductases. Glutathione S-transferases GST catalyse conjugation of xenobiotics to GSH. Fig. 3. The pathway of glutathione biosynthesis in plants. Glutathione is synthesized in two steps, catalyzed by -glutamyl cysteine synthetase...