Nrf1 and Nrf2 positively and c-Fos and Fra1 negatively regulate the human antioxidant response element-mediated expression of NAD(P)H:quinone oxidoreductase1 gene
10 Dec 1996-Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences)-Vol. 93, Iss: 25, pp 14960-14965
TL;DR: It is reported here that Jun, Fos, Fra, and NRF nuclear transcription factors bind to the hARE, indicating that hARE-mediated expression of the NQO1 gene and its induction by xenobiotics and antioxidants are mediated by Nrf1 and Nrf2.
Abstract: Twenty-four base pairs of the human antioxidant response element (hARE) are required for high basal transcription of the NAD(P)H:quinone oxidoreductase1 (NQO1) gene and its induction in response to xenobiotics and antioxidants. hARE is a unique cis-element that contains one perfect and one imperfect AP1 element arranged as inverse repeats separated by 3 bp, followed by a “GC” box. We report here that Jun, Fos, Fra, and Nrf nuclear transcription factors bind to the hARE. Overexpression of cDNA derived combinations of the nuclear proteins Jun and Fos or Jun and Fra1 repressed hARE-mediated chloramphenicol acetyltransferase (CAT) gene expression in transfected human hepatoblastoma (Hep-G2) cells. Further experiments suggested that this repression was due to overexpression of c-Fos and Fra1, but not due to Jun proteins. The Jun (c-Jun, Jun-B, and Jun-D) proteins in all the possible combinations were more or less ineffective in repression or upregulation of hARE-mediated gene expression. Interestingly, overexpression of Nrf1 and Nrf2 individually in Hep-G2 and monkey kidney (COS1) cells significantly increased CAT gene expression from reporter plasmid hARE-thymidine kinase-CAT in transfected cells that were inducible by β-naphthoflavone and tert-butyl hydroquinone. These results indicated that hARE-mediated expression of the NQO1 gene and its induction by xenobiotics and antioxidants are mediated by Nrf1 and Nrf2. The hARE-mediated basal expression, however, is repressed by overexpression of c-Fos and Fra1.
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TL;DR: Observations to date suggest that oxidative stress, chronic inflammation, and cancer are closely linked.
3,922 citations
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...NAD(P)H quinone oxidoreductase 1 [122]...
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TL;DR: It is demonstrated that Nrf2 is essential for the transcriptional induction of phase II enzymes and the presence of a coordinate transcriptional regulatory mechanism for phase II enzyme genes and the nrf2-deficient mice may prove to be a very useful model for the in vivo analysis of chemical carcinogenesis and resistance to anti-cancer drugs.
3,557 citations
TL;DR: The development of Nrf2 knockout mice has provided key insights into the toxicological importance of this pathway, and this review highlights the key elements in this adaptive response to protection against acute and chronic cell injury provoked by environmental stresses.
Abstract: Keap1-Nrf2-ARE signaling plays a significant role in protecting cells from endogenous and exogenous stresses. The development of Nrf2 knockout mice has provided key insights into the toxicological importance of this pathway. These mice are more sensitive to the hepatic, pulmonary, ovarian, and neurotoxic consequences of acute exposures to environmental agents and drugs, inflammatory stresses, as well as chronic exposures to cigarette smoke and other carcinogens. Under quiescent conditions, the transcription factor Nrf2 interacts with the actin-anchored protein Keap1, largely localized in the cytoplasm. This quenching interaction maintains low basal expression of Nrf2-regulated genes. However, upon recognition of chemical signals imparted by oxidative and electrophilic molecules, Nrf2 is released from Keap1, escapes proteasomal degradation, translocates to the nucleus, and transactivates the expression of several dozen cytoprotective genes that enhance cell survival. This review highlights the key elements in this adaptive response to protection against acute and chronic cell injury provoked by environmental stresses.
3,066 citations
TL;DR: The nuclear factor erythroid 2-related factor 2 (Nrf2) is an emerging regulator of cellular resistance to oxidants that controls the basal and induced expression of an array of antioxidant response element-dependent genes to regulate the physiological and pathophysiological outcomes of oxidant exposure.
Abstract: Organismal life encounters reactive oxidants from internal metabolism and environmental toxicant exposure. Reactive oxygen and nitrogen species cause oxidative stress and are traditionally viewed as being harmful. On the other hand, controlled production of oxidants in normal cells serves useful purposes to regulate signaling pathways. Reactive oxidants are counterbalanced by complex antioxidant defense systems regulated by a web of pathways to ensure that the response to oxidants is adequate for the body's needs. A recurrent theme in oxidant signaling and antioxidant defense is reactive cysteine thiol–based redox signaling. The nuclear factor erythroid 2–related factor 2 (Nrf2) is an emerging regulator of cellular resistance to oxidants. Nrf2 controls the basal and induced expression of an array of antioxidant response element–dependent genes to regulate the physiological and pathophysiological outcomes of oxidant exposure. This review discusses the impact of Nrf2 on oxidative stress and toxicity and how...
2,987 citations
Cites background from "Nrf1 and Nrf2 positively and c-Fos ..."
...Nrf2 does not appear to be essential for blood cell differentiation but was found to mediate induction of a set of drug-metabolizing enzymes (DMEs), such as glutathione S-transferase (GST) and NAD(P)H:quinone oxidoreductase 1 (NQO1), by antioxidants and electrophiles (7, 8)....
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TL;DR: A possible role of the Nrf2-antioxidant response element transcriptional pathway in neuroprotection and the nature of this pathway and the mechanisms by which Keap1 acts to repress NRF2 activity are the topics of discussion in this minireview.
2,247 citations
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3,397 citations
TL;DR: Although Nrf2 is expressed ubiquitously, a role of this protein in mediating enhancer activity of hypersensitive site 2 in erythroid cells cannot be excluded and NRF2 contains a powerful acidic activation domain that may participate in the transcriptional stimulation of beta-globin genes.
Abstract: Hypersensitive site 2 located in the beta-globin locus control region confers high levels of expression to the genes of the beta-globin cluster. A tandem repeat of the consensus sequence for the transcription factors AP1 and NF-E2 (activating protein 1 and nuclear factor erythroid 2, respectively) is present within hypersensitive site 2 and is absolutely required for strong enhancer activity. This sequence binds, in vitro and in vivo, to ubiquitous proteins of the AP1 family and to the recently cloned erythroid-specific transcription factor NF-E2. Using the tandem repeat as a recognition site probe to screen a lambda gt11 cDNA expression library from K562 cells, we isolated several DNA binding proteins. Here, we report the characterization of one of the clones isolated. The gene, which we named Nrf2 (NF-E2-related factor 2), is encoded within a 2.2-kb transcript and predicts a 66-kDa protein with a basic leucine zipper DNA binding domain highly homologous to that of NF-E2. Although Nrf2 is expressed ubiquitously, a role of this protein in mediating enhancer activity of hypersensitive site 2 in erythroid cells cannot be excluded. In this respect, Nrf2 contains a powerful acidic activation domain that may participate in the transcriptional stimulation of beta-globin genes.
1,405 citations
TL;DR: This method provides a means for the purification of rare sequence-specific DNA binding proteins, such as Sp1 and CAAT-binding transcription factor, by using tandem affinity columns containing different protein binding sites.
Abstract: We describe a method for affinity purification of sequence-specific DNA binding proteins that is fast and effective. Complementary chemically synthesized oligodeoxynucleotides that contain a recognition site for a sequence-specific DNA binding protein are annealed and ligated to give oligomers. This DNA is then covalently coupled to Sepharose CL-2B with cyanogen bromide to yield the affinity resin. A partially purified protein fraction is combined with competitor DNA and subsequently passed through the DNA-Sepharose resin. The desired sequence-specific DNA binding protein is purified because it preferentially binds to the recognition sites in the affinity resin rather than to the nonspecific competitor DNA in solution. For example, a protein fraction that is enriched for transcription factor Sp1 can be further purified 500- to 1000-fold by two sequential affinity chromatography steps to give Sp1 of an estimated 90% homogeneity with 30% yield. In addition, the use of tandem affinity columns containing different protein binding sites allows the simultaneous purification of multiple DNA binding proteins from the same extract. This method provides a means for the purification of rare sequence-specific DNA binding proteins, such as Sp1 and CAAT-binding transcription factor.
1,058 citations
390 citations
TL;DR: A comparison study of the response of the oxyR Regulon to the Redox Stress and Antibiotic Resistance waves in the controlled setting and that of the controlled environment suggests that the responses are similar to that of a natural environment.
Abstract: INTRODUCTION: REACTIVE OXYGEN AND ITS BIOLOGICAL EFFECTS . . . . . . . . 3 16 Active Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 16 Molecular and Cellular Damage by Oxygen Radicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 RESPONSES TO OXIDATIVE STRESS: PHySIOLOGy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 Hydrogen Peroxide Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Superoxide Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Stationary Phase/Starvation Proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 OXIDATIVE STRESS REGULONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 H202 Response: The oxyR Regulon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 Superoxide Response: The soxRS Regulon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 Stationary Phase/Starvation: The katF Regulon .. . .... ....... 323 soxQ: Redox Stress and Antibiotic Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 CONTROL MECHANISMS ..... . . . . . . . ..... . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 Gene A ctivation by the OxyR Protein . . . .. .... .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 SoxR and SoxS: Two Proteins in Positive Control . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 326 KatF: An A lternative Sigma Factor? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 soxQlcfxB and marA: Genes in a Complex Regulatory Locus. . . . . . . . . . . . . . . . . . . . . . . . . . . 328 EVOLUTIONARY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 The Role of Responses to Oxidative Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Integration of Cellular Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Positive Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Generality of Oxidative Stress Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 OVERVIEW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 332
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