301
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Abstract
Reactive oxygen species are produced by all aerobic cells and are widely believed to play a pivotal role in aging as well as a number of degenerative diseases. The consequences of the generation of oxidants in cells does not appear to be limited to promotion of deleterious effects. Alterations in oxidative metabolism have long been known to occur during differentiation and development. Experimental perturbations in cellular redox state have been shown to exert a strong impact on these processes. The discovery of specific genes and pathways affected by oxidants led to the hypothesis that reactive oxygen species serve as subcellular messengers in gene regulatory and signal transduction pathways. Additionally, antioxidants can activate numerous genes and pathways. The burgeoning growth in the number of pathways shown to be dependent on oxidation or antioxidation has accelerated during the last decade. In the discussion presented here, we provide a tabular summary of many of the redox effects on gene expression and signaling pathways that are currently known to exist.
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Affiliation(s)
- R G Allen
- Lankenau Medical Research Center, Thomas Jefferson University, Wynnewood, PA 19106, USA
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302
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Wong CM, Chun AC, Kok KH, Zhou Y, Fung PC, Kung HF, Jeang KT, Jin DY. Characterization of human and mouse peroxiredoxin IV: evidence for inhibition by Prx-IV of epidermal growth factor- and p53-induced reactive oxygen species. Antioxid Redox Signal 2000; 2:507-18. [PMID: 11229364 DOI: 10.1089/15230860050192288] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study was to identify and characterize human and mouse Prx-IV. We identified mouse peroxiredoxin IV (Prx-IV) by virtue of sequence homology to its human ortholog previously called AOE372. Mouse Prx-IV conserves an amino-terminal presequence coding for signal peptide. The amino acid sequences of mature mouse and human Prx-IV share 97.5% identity. Phylogenetic analysis demonstrates that Prx-IV is more closely related to Prx-I/-II/-III than to Prx-V/-VI. Previously, we mapped the mouse Prx-IV gene to chromosome X by analyzing two sets of multiloci genetic crosses. Here we performed further comparative analysis of mouse and human Prx-IV genomic loci. Consistent with the mouse results, human Prx-IV gene localized to chromosome Xp22.135-136, in close proximity to SAT and DXS7178. A bacterial artificial chromosome (BAC) clone containing the complete human Prx-IV locus was identified. The size of 7 exons and the sequences of the splice junctions were confirmed by PCR analysis. We conclude that mouse Prx-IV is abundantly expressed in many tissues. However, we could not detect Prx-IV in the conditioned media of NIH-3T3 and Jurkat cells. Mouse Prx-IV was specifically found in the nucleus-excluded region of cultured mouse cells. Intracellularly, overexpression of mouse Prx-IV prevented the production of reactive oxygen species induced by epidermal growth factor or p53. Taken together, mouse Prx-IV is likely a cytoplasmic or organellar peroxiredoxin involved in intracellular redox signaling.
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Affiliation(s)
- C M Wong
- Institute of Molecular Biology, The University of Hong Kong, Pokfulam
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303
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The Effects of Bioenergetic Stress and Redox Balance on the Expression of Genes Critical to Mitochondrial Function. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1568-1254(00)80017-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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304
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Juurlink BH. Management of oxidative stress in the CNS: the many roles of glutathione. Neurotox Res 1999; 1:119-40. [PMID: 12835108 DOI: 10.1007/bf03033276] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An outline is given of mechanisms that generate oxidative stress and inflammation. Considered are the metabolic mechanisms that give rise to peroxides, the source of strong oxidants; the production of dicarbonyls that interact with macromolecules to form advanced glycation endproducts; and the role that activation of the transcription factor NF(Kappa)B has in the expression of pro-inflammatory genes. Management of oxidative stress is considered by outlining the central role of reduced glutathione (GSH) in peroxide scavenging, dicarbonyl scavenging and activation of NF(Kappa)B. Cellular GSH levels are dictated by the balance between consumption, oxidation of GSH, reduction of oxidized-glutathione, and synthesis. The rate-limiting enzyme in GSH synthesis is L-gamma-glutamyl-L-cysteine synthase, a phase II enzyme. Phase II enzyme inducers are found in many fruits and vegetables. It is suggested that dietary phase II enzyme inducers be investigated for their potential for preventing or retarding the development of degenerative diseases that have an underlying oxidative stress and inflammatory component.
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Affiliation(s)
- B H Juurlink
- Department of Anatomy and Cell Biology, The Cameco Multiple Sclerosis and Neuroscience Research Centre, College of Medicine, University of Saskatchewan, 107 Wiggins Rd., Saskatoon, SK, S7N 5E5 Canada.
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305
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Abstract
Thiol-dependent hydroperoxide metabolism in parasites is reviewed in respect to potential therapeutic strategies. The hydroperoxide metabolism of Crithidia fasciculata has been characterized to comprise a cascade of three enzymes, trypanothione reductase, tryparedoxin, and tryparedoxin peroxidase, plus two supportive enzymes to synthesize the redox mediator trypanothione from glutathione and spermidine. The essentiality of the system in respect to parasite vitality and virulence has been verified by genetic approaches. The system appears to be common to all genera of the Kinetoplastida. The terminal peroxidase of the system belongs to the protein family of peroxiredoxins which is also represented in Entamoeba and a variety of metazoan parasites. Plasmodial hydroperoxide metabolism displays similarities to the mammalian system in comprising glutathione biosynthesis, glutathione reductase, and at least one glutathione peroxidase homolog having the active site selenocysteine replaced by cysteine. Nothing precise is known about the antioxidant defence systems of Giardia, Toxoplasma, and Trichomonas species. Also, the role of ovothiols and mycothiols reportedly present in several parasites remains to be established. Scrutinizing known enzymes of parasitic antioxidant defence for suitability as drug targets leaves only those of the trypanosomatid system as directly or indirectly validated. By generally accepted criteria of target selection and feasibility considerations tryparedoxin and tryparedoxin peroxidase can at present be rated as the most appealing target structures for the development of antiparasitic drugs.
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Affiliation(s)
- L Flohé
- Department of Biochemistry, Technical University of Braunschweig, Germany.
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306
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Lee TH, Yu SL, Kim SU, Lee KK, Rhee SG, Yu DY. Characterization of mouse peroxiredoxin I genomic DNA and its expression. Gene 1999; 239:243-50. [PMID: 10548725 DOI: 10.1016/s0378-1119(99)00413-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peroxiredoxins (Prxs) are a newly defined family of anti-oxidant proteins that have been implicated, via their anti-oxidant activity, in a number of cellular functions, including cell proliferation and differentiation, protection of other proteins from oxidative damage, and intracellular signaling. We isolated genomic DNA sequences of the Prx I genes from the mouse, and characterized their molecular genetic features. Prx I was found to form a small gene family with two and three members; one functional and two pseudogenes. The Prx I-1 gene has splice donor/acceptor site sequences and five or six exons, whereas the Prx I-2 clone has several structural features characteristic of a typical retroposon found to have ORF sequences. We analyzed the expression of pseudogenes, which were not expressed on the transcription levels in the investigated organs. The functional copy of the Prx I-1 gene was expressed abundantly in liver and kidney of the adult, as well as in early developing embryos. This report, together with amino acid/nucleotide sequence similarity between human and mice, provides a basis for speculating on an even earlier event in the evolution of the Prx I gene family, i.e. the Prx I gene was well conserved in human and mice via its anti-oxidant activity.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Cloning, Molecular
- DNA/chemistry
- DNA/genetics
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Exons
- Gene Expression
- Gene Expression Regulation, Developmental
- Genes/genetics
- Genomic Library
- Introns
- Isoenzymes/genetics
- Male
- Mice
- Mice, Inbred Strains
- Molecular Sequence Data
- Peroxidases/genetics
- Peroxiredoxins
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Nucleic Acid
- Tissue Distribution
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Affiliation(s)
- T H Lee
- Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusong, Taejon, South Korea
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307
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Knoops B, Clippe A, Bogard C, Arsalane K, Wattiez R, Hermans C, Duconseille E, Falmagne P, Bernard A. Cloning and characterization of AOEB166, a novel mammalian antioxidant enzyme of the peroxiredoxin family. J Biol Chem 1999; 274:30451-8. [PMID: 10521424 DOI: 10.1074/jbc.274.43.30451] [Citation(s) in RCA: 195] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Using two-dimensional electrophoresis, we have recently identified in human bronchoalveolar lavage fluid a novel protein, termed B166, with a molecular mass of 17 kDa. Here, we report the cloning of human and rat cDNAs encoding B166, which has been renamed AOEB166 for antioxidant enzyme B166. Indeed, the deduced amino acid sequence reveals that AOEB166 represents a new mammalian subfamily of AhpC/TSA peroxiredoxin antioxidant enzymes. Human AOEB166 shares 63% similarity with Escherichia coli AhpC22 alkyl hydroperoxide reductase and 66% similarity with a recently identified Saccharomyces cerevisiae alkyl hydroperoxide reductase/thioredoxin peroxidase. Moreover, recombinant AOEB166 expressed in E. coli exhibits a peroxidase activity, and an antioxidant activity comparable with that of catalase was demonstrated with the glutamine synthetase protection assay against dithiothreitol/Fe3+/O(2) oxidation. The analysis of AOEB166 mRNA distribution in 30 different human tissues and in 10 cell lines shows that the gene is widely expressed in the body. Of interest, the analysis of N- and C-terminal domains of both human and rat AOEB166 reveals amino acid sequences presenting features of mitochondrial and peroxisomal targeting sequences. Furthermore, human AOEB166 expressed as a fusion protein with GFP in HepG2 cell line is sorted to these organelles. Finally, acute inflammation induced in rat lung by lipopolysaccharide is associated with an increase of AOEB166 mRNA levels in lung, suggesting a protective role for AOEB166 in oxidative and inflammatory processes.
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Affiliation(s)
- B Knoops
- Laboratory of Cell Biology, Department of Biology, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium.
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308
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Grey ST, Arvelo MB, Hasenkamp W, Bach FH, Ferran C. A20 inhibits cytokine-induced apoptosis and nuclear factor kappaB-dependent gene activation in islets. J Exp Med 1999; 190:1135-46. [PMID: 10523611 PMCID: PMC2195658 DOI: 10.1084/jem.190.8.1135] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease resulting from apoptotic destruction of beta cells in the islets of Langerhans. Low expression of antioxidants and a predilection to produce nitric oxide (NO) have been shown to underscore beta cell apoptosis. With this perspective in mind, we questioned whether beta cells could mount an induced protective response to inflammation. Here we show that human and rat islets can be induced to rapidly express the antiapoptotic gene A20 after interleukin (IL)-1beta activation. Overexpression of A20 by means of adenovirus-mediated gene transfer protects islets from IL-1beta and interferon gamma-induced apoptosis. The cytoprotective effect of A20 against apoptosis correlates with and is dependent on the abrogation of cytokine-induced NO production. The inhibitory effect of A20 on cytokine-stimulated NO production is due to transcriptional blockade of inducible NO synthase (iNOS) induction; A20 inhibits the activation of the transcription factor nuclear factor kappaB at a level upstream of IkappaBalpha degradation. These data demonstrate a dual antiapoptotic and antiinflammatory function for A20 in beta cells. This qualifies A20 as part of the physiological cytoprotective response of islets. We propose that A20 may have therapeutic potential as a gene therapy candidate to achieve successful islet transplantation and the cure of IDDM.
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Affiliation(s)
- S T Grey
- Immunobiology Research Center, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA.
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309
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Yanagawa T, Ishikawa T, Ishii T, Tabuchi K, Iwasa S, Bannai S, Omura K, Suzuki H, Yoshida H. Peroxiredoxin I expression in human thyroid tumors. Cancer Lett 1999; 145:127-32. [PMID: 10530780 DOI: 10.1016/s0304-3835(99)00243-8] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Peroxiredoxin I (Prx I) is newly discovered oxidative stress inducible protein, having a thioredoxin peroxidase activity. The Prx I expression level in 107 samples out of 60 thyroid lesions, including normal thyroid, tumors and thyroiditis including Graves' disease were examined using immunoblotting. Prx I expression levels in follicular neoplasm (P = 0.00005) and thyroiditis group (P = 0.0037) were significantly higher than that of the control group, while papillary carcinoma group did not show statistical significance. Immunohistochemistry indicated that Prx I was in epithelial cells of thyroid follicles. These results suggest that Prx I is expected to be a candidate for novel tumor markers to discriminate tissue types of tumors.
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Affiliation(s)
- T Yanagawa
- Division of Head and Neck Surgery, Chiba Cancer Center Hospital, Japan
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310
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Abstract
When life first evolved on Earth, there was little oxygen in the atmosphere. Evolution of antioxidant defences must have been closely associated with the evolution of photosynthesis and of O2-dependent electron transport mechanisms. Studies with mice lacking antioxidant defences confirm the important roles of MnSOD and transferrin in maintaining health, but show that glutathione peroxidase (GPX) and CuZnSOD are not essential for everyday life (at least in mice). Superoxide can be cytotoxic by several mechanisms: one is the formation of hydroxyl radicals. There is good evidence that OH* formation occurs in vivo. Other important antioxidants may include thioredoxin, and selenoproteins other than GPX. Nitric oxide may be an important antioxidant in the vascular system. Diet-derived antioxidants are important in maintaining human health, but recent studies employing "biomarkers" of oxidative DNA damage are questioning the "antioxidant" roles of beta-carotene and ascorbate. An important area of future research will be elucidation of the reasons why levels of steady-state oxidative damage to DNA and lipids vary so much between individuals, and their predictive value for the later development of human disease.
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Affiliation(s)
- B Halliwell
- Department of Biochemistry, National University of Singapore, Singapore
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311
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Abstract
A panel of mineral fibres has been studied for their ability to cause translocation of the transcription factor NF-kappaB to the nucleus in A549 lung epithelial cells. On the basis of inhalation studies, three fibres were designated as being carcinogenic-amosite asbestos, silicon carbide and refractory ceramic fibre 1 (RCF1)-or non-carcinogenic-man-made vitreous fibre (MMVF10), Code 100/475 glass fibre, and RCF4. The experiments were carried out at equal fibre number. It was hypothesized that carcinogenic fibres have greater free radical activity than non-carcinogenic fibres and that an oxidative stress produced in the lung after inhalation of fibres could cause translocation of the transcription factor NF-kappaB to the nucleus, where transcription of pro-inflammatory genes such as cytokines could occur. It was demonstrated that a simple oxidant, hydrogen peroxide, caused translocation in a time- and dose-dependent manner. The three carcinogenic fibres produced a significant dose-dependent translocation of NF-kappaB to the nucleus, whereas the non-carcinogenic fibres did not. Silicon carbide fibres were the most potent of the pathogenic fibres. MMVF10 was the most potent of the non-pathogenic fibres, causing significant nuclear translocation of NF-kappaB at high fibre number. Using three antioxidants, curcumin, pyrrolidine dithiocarbamate, and Nacystelin, translocation caused by carcinogenic fibres could be significantly reduced. The present study shows that a short-term in vitro assay can discriminate between pathogenic and non-pathogenic fibres in terms of a key pro-inflammatory event in epithelial cells. The mechanism of the activation of NF-kappaB by pathogenic fibres and its general applicability to other fibre types remain to be determined.
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Affiliation(s)
- D M Brown
- Department of Biological Sciences, Napier University, Edinburgh, U.K.
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312
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Alphey MS, Leonard GA, Gourley DG, Tetaud E, Fairlamb AH, Hunter WN. The high resolution crystal structure of recombinant Crithidia fasciculata tryparedoxin-I. J Biol Chem 1999; 274:25613-22. [PMID: 10464297 DOI: 10.1074/jbc.274.36.25613] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tryparedoxin-I is a recently discovered thiol-disulfide oxidoreductase involved in the regulation of oxidative stress in parasitic trypanosomatids. The crystal structure of recombinant Crithidia fasciculata tryparedoxin-I in the oxidized state has been determined using multi-wavelength anomalous dispersion methods applied to a selenomethionyl derivative. The model comprises residues 3 to 145 with 236 water molecules and has been refined using all data between a 19- and 1.4-A resolution to an R-factor and R-free of 19.1 and 22.3%, respectively. Despite sharing only about 20% sequence identity, tryparedoxin-I presents a five-stranded twisted beta-sheet and two elements of helical structure in the same type of fold as displayed by thioredoxin, the archetypal thiol-disulfide oxidoreductase. However, the relationship of secondary structure with the linear amino acid sequences is different for each protein, producing a distinctive topology. The beta-sheet core is extended in the trypanosomatid protein with an N-terminal beta-hairpin. There are also differences in the content and orientation of helical elements of secondary structure positioned at the surface of the proteins, which leads to different shapes and charge distributions between human thioredoxin and tryparedoxin-I. A right-handed redox-active disulfide is formed between Cys-40 and Cys-43 at the N-terminal region of a distorted alpha-helix (alpha1). Cys-40 is solvent-accessible, and Cys-43 is positioned in a hydrophilic cavity. Three C-H...O hydrogen bonds donated from two proline residues serve to stabilize the disulfide-carrying helix and support the correct alignment of active site residues. The accurate model for tryparedoxin-I allows for comparisons with the family of thiol-disulfide oxidoreductases and provides a template for the discovery or design of selective inhibitors of hydroperoxide metabolism in trypanosomes. Such inhibitors are sought as potential therapies against a range of human pathogens.
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Affiliation(s)
- M S Alphey
- Department of Biochemistry, The Wellcome Trust Building, University of Dundee, Dundee, DD1 5EH, Scotland, United Kingdom
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313
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Abstract
Intracellular antioxidants include low molecular weight scavengers of oxidizing species, and enzymes which degrade superoxide and hydroperoxides. Such antioxidants systems prevent the uncontrolled formation of free radicals and activated oxygen species, or inhibit their reactions with biological structures. Hydrophilic scavengers are found in cytosolic, mitochondrial and nuclear compartments. Ascorbate and glutathione scavenge oxidizing free radicals in water by means of one-electron or hydrogen atom transfer. Similarly, ergothioneine scavenges hydroxyl radicals at very high rates, but it acts more specifically as a chemical scavenger of hypervalent ferryl complexes, halogenated oxidants and peroxynitrite-derived nitrating species, and as a physical quencher of singlet oxygen. Hydrophobic scavengers are found in cell membranes where they inhibit or interrupt chain reactions of lipid peroxidation. In animal cells, they include alpha-tocopherol (vitamin E) which is a primary scavenger of lipid peroxyl radicals, and carotenoids which are secondary scavengers of free radicals as well as physical quenchers of singlet oxygen. The main antioxidant enzymes include dismutases such as superoxide dismutases (SOD) and catalases, which do not consume cofactors, and peroxidases such as selenium-dependent glutathione peroxidases (GPx) in animals or ascorbate peroxidases (APx) in plants. The reducing coenzymes of peroxidases, and as a rule all reducing components of the antioxidant network, are regenerated at the expense of NAD(P)H produced in specific metabolic pathways. Synergistic and co-operative interactions of antioxidants rely on the sequential degradation of peroxides and free radicals as well as on mutual protections of enzymes. This antioxidant network can induce metabolic deviations and plays an important role in the regulation of protein expression and/or activity at the transcriptional or post-translational levels. Its biological significance is discussed in terms of environmental adaptations and functional regulations of aerobic cells.
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314
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Sakurai A, Hara S, Okano N, Kondo Y, Inoue J, Imura N. Regulatory role of metallothionein in NF-kappaB activation. FEBS Lett 1999; 455:55-8. [PMID: 10428471 DOI: 10.1016/s0014-5793(99)00839-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Metallothionein (MT), a low molecular weight, cysteine-rich metal binding protein, has been associated with cytoprotection from heavy metals and cellular oxidants. As MT has the ability to scavenge hydroxyl radicals, MT may control intracellular redox status. In the present study, we examined whether MT regulates the activity of nuclear factor-kappaB (NF-kappaB), which is one of the redox-regulated transcription factors, using the MT null embryonic cell lines established from MT null mice. We first found that tumor necrosis factor (TNF)-induced activation of the binding of NF-kappaB protein to DNA in wild type MT+/+ cells was lower than that in MT-/- cells. The NF-kappaB activation in MT-expressing cells established from MT-/- cells by the transfection of mouse MT-1 gene was also significantly lower than that in MT-/- cells. In addition, transfection of the MT gene inhibited TNF-induced IkappaB degradation and suppressed NF-kappaB-dependent gene expression induced by TNF. These results demonstrate that MT may function as a negative regulator of NF-kappaB activity.
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Affiliation(s)
- A Sakurai
- Department of Public Health, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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315
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Affiliation(s)
- Nanxin Li
- Laboratory of Gene Regulation and Signal Transduction Department of Pharmacology University of California San Diego, La Jolla California 92093‐0636 USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction Department of Pharmacology University of California San Diego, La Jolla California 92093‐0636 USA
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316
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Jin DY, Giordano V, Kibler KV, Nakano H, Jeang KT. Role of adapter function in oncoprotein-mediated activation of NF-kappaB. Human T-cell leukemia virus type I Tax interacts directly with IkappaB kinase gamma. J Biol Chem 1999; 274:17402-5. [PMID: 10364167 DOI: 10.1074/jbc.274.25.17402] [Citation(s) in RCA: 188] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mechanisms by which the human T-cell leukemia virus type I Tax oncoprotein activates NF-kappaB remain incompletely understood. Although others have described an interaction between Tax and a holo-IkappaB kinase (IKK) complex, the exact details of protein-protein contact are not fully defined. Here we show that Tax binds to neither IKK-alpha nor IKK-beta but instead complexes directly with IKK-gamma, a newly characterized component of the IKK complex. This direct interaction with IKK-gamma correlates with Tax-induced IkappaB-alpha phosphorylation and NF-kappaB activation. Thus, our findings establish IKK-gamma as a key molecule for adapting an oncoprotein-specific signaling to IKK-alpha and IKK-beta.
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Affiliation(s)
- D Y Jin
- Laboratory of Molecular Microbiology, NIAID, National Institutes of Health, Bethesda, Maryland 20892-0460, USA
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317
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Nakaso K, Kitayama M, Ishii T, Bannai S, Yanagawa T, Kimura K, Nakashima K, Ohama E, Yamada K. Effects of kainate-mediated excitotoxicity on the expression of rat counterparts of A170 and MSP23 stress proteins in the brain. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1999; 69:155-63. [PMID: 10366737 DOI: 10.1016/s0169-328x(99)00093-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Stress proteins play important roles in the protective mechanisms under critical conditions for cell survival. We report here the expression of A170 and MSP23, oxidative stress-inducible proteins, under kainate-mediated excitotoxicity in the rat brain. A170 mRNA was significantly induced in the brain 5-8 h after i.p. kainate administration. MSP23 mRNA was observed at quite a low level in the rat brain, and the induction of MSP23 mRNA was not observed during the period 24 h after kainate administration. Immunoblot analysis demonstrated that the maximal expression level of A170 protein occurred 8 h after treatment in each part of the brain. MSP23 protein was constitutively expressed in the brain and the level of this protein was significantly decreased during the period 24 h after kainate administration. In situ hybridization and immunohistochemical studies showed that A170 was expressed predominantly in neurons, especially in pyramidal neurons of the cerebrum and cerebellar Purkinje cells, while MSP23 was expressed in oligodendrocytes. The induction of A170 was observed in the regions which are affected by excitotoxicity and this induction was observed in the earlier phase than cell death. Also, the region which shows high vulnerability to excitotoxicity such as pyramidal cell layer in the hippocampus, showed lower A170 expression than that which shows resistance to excitotoxicity, such as the dentate gyrus in the hippocampus. These results suggest that A170 may play a protective role in the brain under kainate-mediated excitotoxicity.
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Affiliation(s)
- K Nakaso
- Department of Biochemistry, Faculty of Medicine, Tottori University, Yonago, Japan.
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318
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Hirotsu S, Abe Y, Nagahara N, Hori H, Nishino T, Okada K, Hakoshima T. Crystallographic characterization of a stress-induced multifunctional protein, rat HBP-23. J Struct Biol 1999; 126:80-3. [PMID: 10329492 DOI: 10.1006/jsbi.1999.4088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
HBP-23 is a stress-induced multifunctional rat protein that belongs to a novel family of antioxidant proteins, referred to as peroxiredoxins, and exhibits heme-binding and inhibition of c-Abl protein tyrosine kinase. Recombinant HBP-23 was crystallized by a hanging-drop vapor-diffusion method. The crystals belong to space group P41212 or P43212 with unit-cell dimensions of a = b = 73.47 A, c = 210.37 A and contain two protein molecules in the asymmetric unit. A data set at 2.7-A resolution was collected with a cryo-crystallographic technique. Crystals of selenomethionyl HBP-23 were also obtained under the same conditions.
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Affiliation(s)
- S Hirotsu
- Department of Molecular Biology, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Nara, Ikoma, 630-01, Japan
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319
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DeLuca C, Petropoulos L, Zmeureanu D, Hiscott J. Nuclear IkappaBbeta maintains persistent NF-kappaB activation in HIV-1-infected myeloid cells. J Biol Chem 1999; 274:13010-6. [PMID: 10224051 DOI: 10.1074/jbc.274.19.13010] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Monocytic cells exhibit constitutive NF-kappaB activation upon infection with human immunodeficiency virus-1 (HIV-1). Because IkappaBbeta has been implicated in maintaining NF-kappaB.DNA binding, we sought to investigate whether IkappaBbeta was involved in maintaining persistent NF-kappaB activation in HIV-1-infected monocytic cell lines. IkappaBbeta was present in the nucleus of HIV-1-infected cells and participated in the ternary complex formation with NF-kappaB and DNA. In contrast to uninfected cells, the addition of recombinant glutathione S-transferase-IkappaBalpha protein to preformed NF-kappaB.DNA complexes from HIV-1-infected cell extracts did not completely dissociate the complexes, suggesting that IkappaBbeta may protect NF-kappaB complexes from IkappaBalpha-mediated dissociation. Immunodepletion of IkappaBbeta resulted in an NF-kappaB.DNA binding complex that was sensitive to IkappaBalpha-mediated dissociation, thus demonstrating the protective role of IkappaBbeta. In addition, co-transfection studies with an NF-kappaB-dependent reporter construct demonstrated that IkappaBbeta co-expression partially alleviated inhibition of NF-kappaB-mediated gene expression by IkappaBalpha, implying that IkappaBbeta can maintain transcriptionally active NF-kappaB.DNA complexes. Furthermore, constitutive phosphorylation of IkappaBalpha was observed. Immunoprecipitation of the IkappaB kinase (IKK) complex followed by in vitro analysis of kinase activity demonstrated that IKK was constitutively activated in HIV-1-infected myeloid cells. Thus, virus-induced constitutive IKK activation, coupled with the maintenance of a ternary NF-kappaB.DNA complex by IkappaBbeta, maintains persistent NF-kappaB activity in HIV-1-infected myeloid cells.
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Affiliation(s)
- C DeLuca
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
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320
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Sarafian TA, Verity MA, Vinters HV, Shih CCY, Shi L, Ji XD, Dong L, Shau H. Differential expression of peroxiredoxin subtypes in human brain cell types. J Neurosci Res 1999. [DOI: 10.1002/(sici)1097-4547(19990415)56:2<206::aid-jnr10>3.0.co;2-x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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321
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Kawane T, Hou JQ, Sato H, Sugita Y, Bannai S, Ishii T. Induction of metalloelastase mRNA in murine peritoneal macrophages by diethylmaleate. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1427:155-60. [PMID: 10216232 DOI: 10.1016/s0304-4165(99)00018-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Macrophage-specific metalloelastase (MME) hydrolyzes elastin and other matrix proteins and plays an important physiological role in tissue remodeling and pathological tissue destruction. We have examined the effects of diethylmaleate (DEM), an electrophilic agent that reacts with sulfhydryls, on the expression of MME mRNA in mouse peritoneal macrophages. Quantification of MME mRNA by Northern blot analysis revealed that basal mRNA levels were quite low in freshly isolated cells, although mRNA levels increased markedly and reached a steady level within 12 h when cells were cultured in a serum-supplemented RPMI 1640 medium. When macrophages were challenged with DEM at 0.05-1.0 mM for 8 h the expression of the MME gene was enhanced further. In the presence of 0.1 mM DEM, the level of the MME mRNA increased 2-fold compared to the control levels after 6-9 h and decreased to control levels in 24 h. Other electrophilic agents, catechol and 1-chloro-2,4-dinitrobenzene, also enhanced MME gene expression. However, oxidative stress agents such as hydrogen peroxide, menadione, paraquat (an O-2 generator), sodium arsenite and cadmium chloride had no effect on MME gene expression. These results indicate that the electrophilic agents selectively enhance the expression of MME mRNA during primary culture of the macrophages.
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Affiliation(s)
- T Kawane
- Department of Biochemistry, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki 305, Japan
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322
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Differential expression of peroxiredoxin subtypes in human brain cell types. J Neurosci Res 1999. [DOI: 10.1002/(sici)1097-4547(19990415)56:2<206::aid-jnr1>3.0.co;2-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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323
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Minamoto T, Mai M, Ronai Z. Environmental factors as regulators and effectors of multistep carcinogenesis. Carcinogenesis 1999; 20:519-27. [PMID: 10223177 DOI: 10.1093/carcin/20.4.519] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This review highlights current knowledge of environmental factors in carcinogenesis and their cellular targets. The hypothesis that environmental factors influence carcinogenesis is widely supported by both epidemiological and experimental studies. The fact that only a small fraction of cancers can be attributed to germline mutations in cancer-related genes further buttresses the importance of environmental factors in carcinogenesis. Furthermore, penetrance of germline mutations may be modified by either environmental or other genetic factors. Examples of environmental factors that have been associated with increased cancer risk in the human population include chemical and physical mutagens (e.g. cigarette smoke, heterocyclic amines, asbestos and UV irradiation), infection by certain viral or bacterial pathogens, and dietary non-genotoxic constituents (e.g. macro- and micronutrients). Among molecular targets of environmental influences on carcinogenesis are somatic mutation (genetic change) and aberrant DNA methylation (epigenetic change) at the genomic level and post-translational modifications at the protein level. At both levels, changes elicited affect either the stability or the activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. Together, via multiple genetic and epigenetic lesions, environmental factors modulate important changes in the pathway of cellular carcinogenesis.
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Affiliation(s)
- T Minamoto
- Ruttenberg Cancer Center, Mount Sinai School of Medicine, New York, NY 10029, USA
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324
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Jin DY, Jeang KT. Isolation of full-length cDNA and chromosomal localization of human NF-kappaB modulator NEMO to Xq28. J Biomed Sci 1999; 6:115-20. [PMID: 10087442 DOI: 10.1007/bf02256442] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
NEMO is an essential component of the IkappaB kinase complex. Others have shown that expression of mouse NEMO can complement the lack of responsiveness to NF-kappaB stimuli in two NEMO-deficient cell lines. Here we report the isolation of a full-length human NEMO cDNA. Virtual translation of human NEMO cDNA predicts a 48-kD coiled-coil protein which shares 87.9% identity and 90.5% similarity with the mouse homolog. By sequence alignment, we mapped the human NEMO gene to chromosome Xq28. We note that the NEMO and the G6PD (glucose-6-phosphate dehydrogenase) loci are arranged in a head-to-head orientation separated by no more than 800 bp. This map location is further supported by the sequence of an alternatively spliced variant of human NEMO mRNA. Thus, human NEMO is an X-linked gene closely adjacent to the G6PD locus.
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Affiliation(s)
- D Y Jin
- Molecular Virology Section, Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, Md., USA
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325
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Lee SR, Kim JR, Kwon KS, Yoon HW, Levine RL, Ginsburg A, Rhee SG. Molecular cloning and characterization of a mitochondrial selenocysteine-containing thioredoxin reductase from rat liver. J Biol Chem 1999; 274:4722-34. [PMID: 9988709 DOI: 10.1074/jbc.274.8.4722] [Citation(s) in RCA: 205] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A thioredoxin reductase (TrxR), named here TrxR2, that did not react with antibodies to the previously identified TrxR (now named TrxR1) was purified from rat liver. Like TrxR1, TrxR2 was a dimeric enzyme containing selenocysteine (Secys) as the COOH-terminal penultimate residue. A cDNA encoding TrxR2 was cloned from rat liver; the open reading frame predicts a polypeptide of 526 amino acids with a COOH-terminal Gly-Cys-Secys-Gly motif provided that an in-frame TGA codon encodes Secys. The 3'-untranslated region of the cDNA contains a canonical Secys insertion sequence element. The deduced amino acid sequence of TrxR2 shows 54% identity to that of TrxR1 and contained 36 additional residues upstream of the experimentally determined NH2-terminal sequence. The sequence of this 36-residue region is typical of that of a mitochondrial leader peptide. Immunoblot analysis confirmed that TrxR2 is localized almost exclusively in mitochondria, whereas TrxR1 is a cytosolic protein. Unlike TrxR1, which was expressed at a level of 0.6 to 1.6 microgram/milligram of total soluble protein in all rat tissues examined, TrxR2 was relatively abundant (0.3 to 0.6 microgram/mg) only in liver, kidney, adrenal gland, and heart. The specific localization of TrxR2 in mitochondria, together with the previous identification of mitochondria-specific thioredoxin and thioredoxin-dependent peroxidase, suggest that these three proteins provide a primary line of defense against H2O2 produced by the mitochondrial respiratory chain.
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Affiliation(s)
- S R Lee
- Laboratory of Cell Signaling, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, USA
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326
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Matsumoto A, Okado A, Fujii T, Fujii J, Egashira M, Niikawa N, Taniguchi N. Cloning of the peroxiredoxin gene family in rats and characterization of the fourth member. FEBS Lett 1999; 443:246-50. [PMID: 10025941 DOI: 10.1016/s0014-5793(98)01736-0] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Peroxiredoxin (PRx) exhibits thioredoxin-dependent peroxidase activity and constitutes a family of proteins. Four members of genes from rat tissues were isolated by PCR using degenerated primers based on the sequences which encode a pair of highly conserved Cys-containing domains, and were then cloned to full-length cDNAs. These included two genes which have previously been isolated in rats, PRx I and PRx II, and two rat homologues of PRx III and PRx IV. We showed, for the first time, the simultaneous expression of all four genes in various rat tissues by Northern blotting. Since a discrepancy exists regarding cellular distribution, we further characterized PRx IV by expressing it in COS-1 cells. This clearly demonstrates that PRx IV is a secretory form and functions within the extracellular space.
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Affiliation(s)
- A Matsumoto
- Department of Biochemistry, Osaka University Medical School, Suita, Japan
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327
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Sacht G, Brigelius-Flohé R, Kiess M, Sztajer H, Flohé L. ATP-sensitive association of mortalin with the IL-1 receptor type I. Biofactors 1999; 9:49-60. [PMID: 10221157 DOI: 10.1002/biof.5520090107] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Interleukin-1 (IL-1) is a major proinflammatory cytokine mediating local and systemic responses of the immune system. Two types of IL-1 receptors are known, but only the IL-1 receptor type I initiates biological responses. Here we show that two proteins with nucleic acid binding potential and mortalin, a member of the HSP70-family, are associated with the IL-1 receptor type I irrespective of IL-1 binding. The association of mortalin with the IL-1 receptor type I is specifically reversed by ATP concentrations in the physiological range. Other nucleotides are not or much less effective. The in vitro dissociation of mortalin effects neither the receptor association nor the activity of IRAK, which initiates the IL-1-dependent phosphorylation cascade. The roles of the receptor-associated proteins are therefore discussed in the context of receptor internalisation.
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Affiliation(s)
- G Sacht
- Technical University of Braunschweig, Department of Biochemistry, Germany
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328
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Affiliation(s)
- S G Rhee
- Laboratory of Cell Signaling, NHLBI, National Institutes of Health, Bethesda, MD 20892, USA
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329
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Butterfield LH, Merino A, Golub SH, Shau H. From cytoprotection to tumor suppression: the multifactorial role of peroxiredoxins. Antioxid Redox Signal 1999; 1:385-402. [PMID: 11233141 DOI: 10.1089/ars.1999.1.4-385] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the past decade, a new family of highly conserved antioxidant enzymes, Peroxiredoxins (Prxs), have been discovered and defined. There are two major Prx subfamilies: one subfamily uses two conserved cysteines (2-Cys) and the other uses 1-Cys to scavenge reactive oxygen species (ROS). This review focuses on the four mammalian 2-Cys members (Prx I-IV) that utilize thioredoxin as the electron donor for antioxidation. The array of biological activities of these proteins suggests that they may be evolutionarily important for cell function. For example, Prxs are capable of protecting cells from ROS insult and regulating the signal transduction pathways that utilize c-Abl, caspases, nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) to influence cell growth and apoptosis. Prxs are also essential for red blood cell (RBC) differentiation and are capable of inhibiting human immunodeficiency virus (HIV) infection and organ transplant rejection. Distribution patterns indicate that Prxs are highly expressed in the tissues and cells at risk for diseases related to ROS toxicity, such as Alzheimer's and Parkinson's diseases and atherosclerosis. This interesting correlation suggests that Prxs are protective against ROS toxicity, yet overwhelmed by oxidative stress in some cells. Prxs tend to form large aggregates at high concentrations, a feature that may interfere with their normal protective function or may even render them cytotoxic. Imbalance in the expression of subtypes can also potentially increase their susceptibility to oxidative stress. Understanding the function and biological role of Prxs may lead to important discoveries about the cellular dysfunction of ROS-related diseases ranging from atherosclerosis to cancer to neurodegenerative diseases.
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Affiliation(s)
- L H Butterfield
- Division of Surgical Oncology, UCLA School of Medicine, Los Angeles, CA 90095-1782, USA
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330
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Li JJ, Oberley LW, Fan M, Colburn NH. Inhibition of AP-1 and NF-kappaB by manganese-containing superoxide dismutase in human breast cancer cells. FASEB J 1998; 12:1713-23. [PMID: 9837861 DOI: 10.1096/fasebj.12.15.1713] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
One of the primary antioxidant enzymes, manganese-containing superoxide dismutase (MnSOD), has shown the ability to reverse malignant phenotypes in a variety of human tumor cells that are low or absent in MnSOD expression. We have observed that overexpression of human MnSOD in human breast cancer MCF-7 cells inhibits tumor growth both in vitro and in vivo. The signaling pathway underlying the MnSOD induced tumor suppression is unknown. We demonstrate here that transcriptional and DNA binding ability of AP-1 and NF-kappaB, but not SP-1, were inhibited (by 50%) in the MCF-7 cell line overexpressing MnSOD. When transiently expressing, MnSOD inhibited AP-1 but increased NF-kappaB transactivation, which can be abolished by sodium pyruvate, a hydrogen peroxide scavenger. To analyze the target genes responsible for MnSOD-induced tumor suppression, genes related to tumor growth and responsive to AP-1 or NF-kappaB were analyzed. AP-1 responsive collagenase I, stromelysin I, and NF-kappaB responsive IL-1 and IL-6 were down-regulated in the MnSOD stable transfectants compared to the control cell lines. Since TPA induces differentiation in human breast cancer cells and up-regulates MnSOD gene in HeLa cells, MnSOD expression and AP-1 and NF-kappaB activity were measured under TPA treatment. The results showed that TPA induced endogenous MnSOD expression and inhibited both AP-1 and NF-kappaB. Together, these results suggest that tumor suppression by overexpressing MnSOD is related to a modulation of AP-1 and NF-kappaB, which causes a down-regulation of genes responsible for tumor malignant phenotype.
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Affiliation(s)
- J J Li
- Gene Regulation Section, Laboratory of Biochemical Physiology, National Cancer Institute, Frederick, Maryland 21702-1201, USA.
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331
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Taketani S, Adachi Y, Kohno H, Ikehara S, Tokunaga R, Ishii T. Molecular characterization of a newly identified heme-binding protein induced during differentiation of urine erythroleukemia cells. J Biol Chem 1998; 273:31388-94. [PMID: 9813049 DOI: 10.1074/jbc.273.47.31388] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A heme-binding protein with a molecular mass of 22 kDa, termed p22 HBP, was purified from mouse liver cytosol, using blue Sepharose CL-6B. We identified a cDNA encoding p22 HBP, and sequence analysis revealed that p22 HBP comprises 190 amino acid residues (Mr 21,063) and has no homology to any other known heme-binding protein. The p22 HBP mRNA (approximately 1.0 kilobases) is ubiquitously expressed in various tissues and is extremely abundant in the liver. cDNA allows for expression of active p22 HBP, with a high affinity for 55Fe-hemin, with a Kd of 26 +/-1.8 nM. The Bmax of hemin binding to p22 HBP was 0.55 +/- 0.021 mol/mol of protein, a value consistent with one heme molecule binding per molecule of protein. The order of potency of different ligands to compete against 55Fe-hemin binding to p22 HBP was hemin = protoporphyrin IX > coproporphyrin III > bilirubin > palmitic acid > all-trans-retinoic acid. Treatment of mouse erythroleukemia (MEL) cells with dimethyl sulfoxide or hemin resulted in an increase in p22 HBP mRNA. The immunoblot analysis showed that p22 HBP increased with time in dimethyl sulfoxide- and hemin-induced MEL cells. Conversely, transfer of antisense oligonucleotides to p22 HBP cDNA resulted in a decrease of p22 HBP in dimethyl sulfoxide-treated MEL cells, and the heme content in these cells decreased to 66-71% of sense oligonucleotides-transferred cells. Thus, this newly identified heme-binding protein, p22 HBP, may be involved in heme utilization for hemoprotein synthesis and even be coupled to hemoglobin synthesis during erythroid differentiation.
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Affiliation(s)
- S Taketani
- Department of Hygiene, Kansai Medical University, Moriguchi, Osaka 570-8506, Japan.
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332
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Phelan SA, Johnson KA, Beier DR, Paigen B. Characterization of the murine gene encoding Aop2 (antioxidant protein 2) and identification of two highly related genes. Genomics 1998; 54:132-9. [PMID: 9806838 DOI: 10.1006/geno.1998.5568] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mouse Aop2 (antioxidant protein 2) cDNA recently cloned from liver and kidney is a member of the thiol-specific antioxidant gene family. We have isolated the mouse gene encoding Aop2 and have shown that it comprises five exons and four introns. Analysis of the sequence upstream of the translation start site revealed several potential Sp1-binding sites and two putative transcription initiation sites. Primer extension studies were used to determine the 5' end of the Aop2 transcript. This upstream region also contains consensus recognition sequences for the transcription factors USF, SREBP, and ADR1, all of which have been shown to regulate genes involved in lipid metabolism, and multiple consensus binding sites for HSF, whose activity is modulated by oxidative stress. Since Aop2 has recently been proposed as a candidate gene for atherosclerosis susceptibility differences in mice, the presence of these binding sites may have biological significance. We also isolated two highly related intronless genes and determined their chromosomal locations. Further characterization of this highly conserved gene family and its regulation will help to elucidate their biological functions.
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Affiliation(s)
- S A Phelan
- The Jackson Laboratory, Bar Harbor, Maine, 04609, USA.
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333
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Schröder E, Ponting CP. Evidence that peroxiredoxins are novel members of the thioredoxin fold superfamily. Protein Sci 1998; 7:2465-8. [PMID: 9828014 PMCID: PMC2143874 DOI: 10.1002/pro.5560071125] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Peroxiredoxins catalyze reduction of hydrogen peroxide or alkyl peroxide, to water or the corresponding alcohol. Detailed analysis of their sequences indicates that these enzymes possess a thioredoxin (Trx)-like fold and consequently are homologues of both thioredoxin and glutathione peroxidase (GPx). Sequence- and structure-based multiple sequence alignments indicate that the peroxiredoxin active site cysteine and GPx active site selenocysteine are structurally equivalent. Homologous peroxiredoxin and GPx enzymes are predicted to catalyze equivalent reactions via similar reaction intermediates.
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Affiliation(s)
- E Schröder
- Department of Chemistry, University of Exeter, United Kingdom
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334
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Tetaud E, Fairlamb AH. Cloning, expression and reconstitution of the trypanothione-dependent peroxidase system of Crithidia fasciculata. Mol Biochem Parasitol 1998; 96:111-23. [PMID: 9851611 DOI: 10.1016/s0166-6851(98)00120-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
As a consequence of aerobic metabolism, trypanosomatids are exposed to reactive oxygen intermediates such as superoxide, hydrogen peroxide and the hydroxyl radical. Metabolism of hydrogen peroxide in Crithidia fasciculata is accomplished by three distinct proteins, tryparedoxin, tryparedoxin peroxidase and trypanothione reductase, working in concert with the substrates NADPH and trypanothione. Here, we report the cloning and characterisation of the tryparedoxin (TryX) and tryparedoxin peroxidase (TryP) genes from C. fasciculata. Both genes are multicopy and organized in distinct tandem arrays in the genome. TryX encodes a 16 kDa protein, which belongs to the thioredoxin superfamily, sharing the WCPPC motif, whereas TryP encodes a 21 kDa protein belonging to a new class of peroxidases called 2-Cys peroxidoxins. Both TryX and TryP were expressed in Escherichia coli and the purified recombinant proteins shown to utilise hydrogen peroxide in the presence of NADPH, trypanothione and trypanothione reductase, similar to the native proteins. TryX is rapidly reduced by trypanothione, but weakly by glutathionylspermidine, glutathione or ovothiol A. TryP shows a broad substrate specificity and can reduced hydrogen peroxide, t-butyl hydroperoxide and cumene hydroperoxide with equal efficiency.
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Affiliation(s)
- E Tetaud
- Department of Biochemistry, University of Dundee, Scotland, UK
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335
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Haridas V, Ni J, Meager A, Su J, Yu GL, Zhai Y, Kyaw H, Akama KT, Hu J, Van Eldik LJ, Aggarwal BB. Cutting Edge: TRANK, a Novel Cytokine That Activates NF-κB and c-Jun N-Terminal Kinase. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
We searched the expressed sequence tag database using sequence homology and identified a novel cytokine, which we have named TRANK (thioredoxin peroxidase-related activator of NF-κB and c-Jun N-terminal kinase). The predicted amino acid sequence of TRANK was highly homologous to that of the thiol-specific antioxidant proteins. Unlike these proteins, however, TRANK had a putative secretory signal polypeptide and was found to be secreted by cells. TRANK was expressed in most tissues and cell lines, and the gene that encodes it was mapped to chromosome Xp21–22.1. TRANK activated NF-κB and induced the degradation of the inhibitory subunit of NF-κB. In addition, TRANK up-regulated the expression of NF-κB-dependent gene products, ICAM-1, and inducible nitric oxide synthase. TRANK also activated c-Jun N-terminal kinase and induced the proliferation of normal human foreskin fibroblasts. Its homology with antioxidant proteins, wide distribution in tissues, and ability to activate NF-κB and c-Jun N-terminal kinase suggest that TRANK plays an important role in inflammation.
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Affiliation(s)
- Valsala Haridas
- *Cytokine Research Section, Department of Molecular Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030
| | - Jian Ni
- †Human Genome Sciences, Inc., Rockville, MD 20850
| | - Anthony Meager
- ‡Division of Immunobiology, The National Institute for Biological Standards and Control, South Mimms, U.K.; and
| | - Jeffery Su
- †Human Genome Sciences, Inc., Rockville, MD 20850
| | - Guo-Liang Yu
- †Human Genome Sciences, Inc., Rockville, MD 20850
| | - Yifan Zhai
- †Human Genome Sciences, Inc., Rockville, MD 20850
| | - Hla Kyaw
- †Human Genome Sciences, Inc., Rockville, MD 20850
| | - Keith T. Akama
- §Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, IL 60611
| | - Jingru Hu
- §Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, IL 60611
| | - Linda J. Van Eldik
- §Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, IL 60611
| | - Bharat B. Aggarwal
- *Cytokine Research Section, Department of Molecular Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030
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336
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Affiliation(s)
- I Rahman
- Department of Medicine, University of Edinburgh, Royal Infirmary, UK
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337
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Chen L, Xie QW, Nathan C. Alkyl hydroperoxide reductase subunit C (AhpC) protects bacterial and human cells against reactive nitrogen intermediates. Mol Cell 1998; 1:795-805. [PMID: 9660963 DOI: 10.1016/s1097-2765(00)80079-9] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In Salmonella typhimurium, ahpC encodes subunit C of alkyl hydroperoxide reductase, an enzyme that reduces organic peroxides. Here, we asked if ahpC could protect cells from reactive nitrogen intermediates (RNI). Salmonella disrupted in ahpC became hypersusceptible to RNI. ahpC from either Mycobacterium tuberculosis or S. typhimurium fully complemented the defect. Unlike protection against cumene hydroperoxide, protection afforded by ahpC against RNI was independent of the reducing flavoprotein, AhpF. Mycobacterial ahpC protected human cells from necrosis and apoptosis caused by RNI delivered exogenously or produced endogenously by transfected nitric oxide synthase. Resistance to RNI appears to be a physiologic function of ahpC. ahpC is the most widely distributed gene known that protects cells directly from RNI, and provides an enzymatic defense against an element of antitubercular immunity.
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Affiliation(s)
- L Chen
- Seaver Laboratory, Department of Medicine, Cornell University Medical College, New York, New York 10021, USA
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338
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Choi HJ, Kang SW, Yang CH, Rhee SG, Ryu SE. Crystal structure of a novel human peroxidase enzyme at 2.0 A resolution. NATURE STRUCTURAL BIOLOGY 1998; 5:400-6. [PMID: 9587003 DOI: 10.1038/nsb0598-400] [Citation(s) in RCA: 313] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hydrogen peroxide (H2O2) has been implicated recently as an intracellular messenger that affects cellular processes including protein phosphorylation, transcription and apoptosis. A set of novel peroxidases, named peroxiredoxins (Prx), regulate the intracellular concentration of H2O2 by reducing it in the presence of an appropriate electron donor. The crystal structure of a human Prx enzyme, hORF6, reveals that the protein contains two discrete domains and forms a dimer. The N-terminal domain has a thioredoxin fold and the C-terminal domain is used for dimerization. The active site cysteine (Cys 47), which exists as cysteine-sulfenic acid in the crystal, is located at the bottom of a relatively narrow pocket. The positively charged environment surrounding Cys 47 accounts for the peroxidase activity of the enzyme, which contains no redox cofactors.
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Affiliation(s)
- H J Choi
- Division of Protein Engineering, Korea Research Institute of Bioscience and Biotechnology, KIST, Yusong, Taejon, South Korea
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