Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05412 (c-Jun)
 11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human proenkephalin gene transcription is transactivated by human T-cell leukemia virus type I (HTLV-I) Tax in human Jurkat T lymphocytes. This transactivation was further enhanced in Jurkat cells treated with concanavalin A, cyclic AMP, or 12-O-tetradecanoylphorbol-13-acetate. Deletion and cis-element transfer analyses of the human proenkephalin promoter identified a cyclic AMP-responsive AP-1 element (-92 to -86) as both necessary and sufficient to confer Tax-dependent transactivation. Different AP-1 or cyclic AMP-responsive element-binding protein (CREB)/activating transcription factor (ATF) proteins which bind this element were expressed in murine teratocarcinoma F9 cells to identify those capable of mediating Tax-dependent transactivation of human proenkephalin gene transcription. Although CREB, c-Fos, c-Jun, and JunD did not have significant effects, JunB inhibited the Tax-dependent transactivation. In contrast, ATF3 dramatically induced Tax-dependent transactivation, which was further enhanced by protein kinase A. Electrophoretic mobility shift assays with recombinant fusion proteins expressed and purified from bacteria indicate that the DNA-binding activity of ATF3 is also dramatically enhanced by Tax. Chimeric fusion proteins consisting of the DNA-binding domain of the yeast transcription factor Gal4 and the amino-terminal domain (residues 1 to 66) of ATF3 were able to mediate Tax-dependent transactivation of a Gal4-responsive promoter, which suggests a direct involvement of this region of ATF3. Recombinant fusion proteins of glutathione S-transferase with either the amino- or carboxy-terminal (residues 139 to 181) domain of ATF3 were able to specifically interact with Tax. Furthermore, specific antisera directed against Tax coimmunoprecipitated ATF3 only in the presence of Tax.
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PMID:Novel interactions between human T-cell leukemia virus type I Tax and activating transcription factor 3 at a cyclic AMP-responsive element. 800 91

Association of the human c-Jun and c-Fos proteins depends upon interactions involving their leucine zipper domains. We are interested in elucidating the tertiary structure of the Jun and Fos leucine zipper domains with a view to understanding the precise intermolecular interactions which govern the affinity and specificity of interaction in these proteins, which have the unusual capacity to form either homodimeric or heterodimeric zipper pairs. With this goal in mind, we have developed a bacterial expression system for the efficient production of both unlabelled and isotopically labelled c-Jun leucine zipper domain. A synthetic junLZ gene was created by annealing, ligation, and polymerase-chain-reaction amplification of overlapping synthetic oligonucleotides which comprised 132 bp of coding sequence encompassing residues Arg276-Asn314 of c-Jun plus a total of five engineered non-native residues at the N- and C-termini. The junLZ gene was cloned into the pGEX-2T vector from which recombinant c-Jun leucine zipper domain (rJunLZ; 46 residues, 5.1 kDa) was overexpressed (approximately 15% total cell protein) in Escherichia coli as a fusion protein of 31.4 kDa, consisting of rJunLZ fused to the carboxy-terminal portion of Schistosoma japonicum glutathione S-transferase. Two markedly different expression strategies have been devised which allow purification of rJunLZ from the soluble or inclusion-body fraction of induced cells. We have used these strategies to produce unlabelled and uniformly 15N-labelled rJunLZ for NMR studies which, in combination with circular dichroic measurements, reveal that rJunLZ most likely forms a symmetric coiled-coil of parallel alpha-helices. We also present 15N-NMR chemical shift assignments for the backbone and sidechain amide nitrogens of rJunLZ, which should assist in determination of a high-resolution structure of the homodimeric Jun leucine zipper using heteronuclear three-dimensional NMR spectroscopy.
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PMID:Cloning, expression, and spectroscopic studies of the Jun leucine zipper domain. 811 39

Induction of mouse glutathione S-transferase (GST) Ya gene expression by a variety of chemical agents is mediated by a regulatory element, EpRE, composed of an Ets and two adjacent AP-1-like binding sites. In this report we present evidence that the basal and inducible activity of EpRE is mediated by AP-1 transcription factor and that the cooperative interaction between AP-1 and an Ets protein contributes to enhance the EpRE inducibility. We also show that EpRE, similar to a single AP-1 site, when ligated to GST Ya gene promoter, is transactivated by c-Fos/c-Jun or c-Fos/Jun-B heterodimer and that c-Jun/c-Jun homodimer is an activator of an AP-1 site only in the context of collagenase gene promoter.
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PMID:Cooperative interaction between Ets and AP-1 transcription factors regulates induction of glutathione S-transferase Ya gene expression. 816 97

Elevated levels of the human pi class glutathione S-transferase (GSTP1-1) have been implicated in the development of antineoplastic drug resistance. Using GSTP1 promoter deletion constructs we have shown that enhanced GSTP1 transcription (up to 18-fold) is the predominant mechanism responsible for increased GSTP1-1 levels in a multidrug resistant derivative (VCREMS) of the human mammary carcinoma cell line MCF7. Furthermore, disruption of a putative AP-1 response element within the GSTP1 promoter (nucleotides -69 to -63) abrogated GSTP1 transcription in both cell lines. In addition, band shift assays demonstrated binding of a VCREMS nuclear complex to the promoter region C1 (-73 to -54) which could be competed for by a DNA fragment containing a known AP-1 binding site from the human collagenase promoter. However, no such competition was observed for the major MCF7 C1 complex. The role of a Fos-Jun-like complex in regulating GSTP1 transcription in VCREMS cells was further emphasized by the introduction of point mutations within the C1 region which were known to inhibit AP-1 binding and the interaction of antisera raised against human c-Jun and c-Fos with the major C1 complex in VCREMS cells. These studies therefore highlight cell-specific differences in the binding pattern of Jun and Fos proteins to the GSTP1 promoter which are likely to play an important role in regulating transcriptional activation of the GSTP1 gene in drug-resistant breast cancer cells.
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PMID:Involvement of Jun and Fos proteins in regulating transcriptional activation of the human pi class glutathione S-transferase gene in multidrug-resistant MCF7 breast cancer cells. 820 48

We have previously identified a novel xenobiotic responsive element, which has been termed the antioxidant responsive element (ARE), in the 5'-flanking region of the rat quinone reductase gene (Favreau, L. V., and Pickett, C. B. (1991) J. Biol. Chem. 266, 4556-4561). This element is responsible for basal level expression of the gene as well as transcriptional activation by phenolic antioxidants and metabolizable planar aromatic compounds. In this communication, we demonstrate that hydrogen peroxide can act as an inducer through the ARE sequence, a phenomenon recently demonstrated for the glutathione S-transferase Ya subunit gene (Rushmore, T. H., Morton, M. R., and Pickett, C. B. (1991) J. Biol. Chem. 266, 11632-11639). To further characterize the quinone reductase ARE, we demonstrate by DNase I footprinting that in crude Hep G2 nuclear extracts a trans-acting factor exists which interacts with a region of DNA found within the 31-nucleotide ARE sequence. Furthermore, electrophoretic mobility shift assays demonstrate the presence of a specific DNA-protein complex which can be competed only by double-stranded oligonucleotides containing the ARE sequences from the quinone reductase and glutathione S-transferase Ya subunit genes. Methylation interference and protection assays indicate that several guanine residues found in the sequence GTGACTTGGC are involved in the binding of the nuclear factor(s) to the DNA. Although electrophoretic mobility shift assays indicate that the rat quinone reductase ARE does not contain a high affinity recognition site for in vitro translated c-Jun and c-Fos, 12-O-tetradecanoylphorbol 13-acetate can act as an inducer through the ARE sequence in Hep G2 cells.
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PMID:Transcriptional regulation of the rat NAD(P)H:quinone reductase gene. Characterization of a DNA-protein interaction at the antioxidant responsive element and induction by 12-O-tetradecanoylphorbol 13-acetate. 839 48

Glutathione transferase P (GST-P) is specifically induced in rat liver and kidney by lead cation. The increase of GST-P mRNA after lead administration is blocked by actinomycin D, suggesting that GST-P production by lead is regulated at the transcriptional level. To further determine which part of the flanking region of the GST-P gene has the lead-responsive cis-element in vivo, we utilized transgenic rats with five different constructs having GST-P and/or chloramphenicol acetyl-transferase coding sequence. We studied the effect of lead on these transgenic rats and on transfected NRK (normal rat kidney) cells and found that GST-P induction by lead is indeed regulated at the transcriptional level and that the GST-P enhancer I (GPEI) enhancer is an essential cis-element required for the activation of the GST-P gene by lead. GPEI consists of two AP-1 (c-Jun/c-Fos heterodimer) site-like sequences that are palindromically arranged and can bind AP-1, c-jun mRNA in the liver increased after lead administration and GST-P, and c-Jun had patchy expression in the same hepatocytes 24 h after lead exposure. These results suggest that activation of the GST-P gene by lead is mediated in major part by enhancer GPEI and that AP-1 may be involved at least partially. GPEI has been shown to have essential sequence information for the trans-activation of the GST-P gene during chemical hepatocarcinogenesis of the rat (Morimura, S., Suzuki, T., Hochi, S., Yuki, A., Nomura, K., Kitagawa, T., Nagatsu, I., Imagawa, M., and Muramatsu, M. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 2065-2068; Suzuki, T., Imagawa, M., Hirabayashi, M., Yuki, A., Hisatake, K., Nomura, K., Kitagawa, T., and Muramatsu, M. (1995) Cancer Res. 55, 2651-2655). The present study establishes that the same enhancer element does operate in the activation of the GST-P gene by lead regardless of the trans-activators involved.
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PMID:Activation of glutathione transferase P gene by lead requires glutathione transferase P enhancer I. 857 62

The effects of EGF, TPA, UV radiation, okadaic acid and anisomycin on ERK and JNK/SAPK MAP kinase cascades have been compared with their ability to elicit histone H3/HMG-14 phosphorylation and induce c-fos and c-jun in C3H 10T1/2 cells. EGF and UV radiation activate both ERKs and JNK/SAPKs but to markedly different extents; EGF activates ERKs more strongly than JNK/SAPKs, whereas UV radiation activates JNK/SAPKs much more strongly than ERKs. Anisomycin and okadaic acid activate JNK/SAPKs but not ERKs, and conversely, TPA activates ERKs but not JNK/SAPKs. Nevertheless, all these agents elicit phosphorylation of ribosomal and pre-ribosomal S6, histone H3 and HMG-14, and the induction of c-fos and c-jun, showing that neither cascade is absolutely essential for these responses. We then analysed the relationship between ERKs, JNK/SAPKs and the transcription factors Elk-1 and c-Jun, implicated in controlling c-fos and c-jun, respectively. JNK/SAPKs bind to GST-cJun1-79, and ERKs, particularly ERK-2, to GST-Elk1(307-428); there is no cross-specificity of binding. Further, GST-Elk1(307-428) binds preferentially to active rather than inactive ERK-2. In vitro, JNK/SAPKs phosphorylate both GST-cJun1-79 and GST-Elk1(307-428), whereas ERKs phosphorylate GST-Elk1(307-428) but not GST-cJun1-79. Thus, neither ERKs nor JNK/SAPKs are absolutely essential for nuclear signalling and c-fos and c-jun induction. The data suggest either that activation of a single MAP kinase subtype is sufficient to elicit a complete nuclear response, or that other uncharacterised routes exist.
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PMID:Neither ERK nor JNK/SAPK MAP kinase subtypes are essential for histone H3/HMG-14 phosphorylation or c-fos and c-jun induction. 858 71

Bacterial LPS stimulation of murine macrophages leads to increased tyrosine phosphorylation and activation of the 42- and 44-kDa mitogen-activated protein kinases (MAPK) and the activation of stress-activated protein kinases (SAPK)/c-Jun N-terminal kinase (JNK) and p38, related to the high osmolarity glycerol protein kinase in Saccharomyces cerevisiae (HOG1). LPS caused a rapid increase (10 min) in phosphotransferase activity toward myelin basic protein (MBP), a polypeptide that encompassed the first 169 residues of c-Jun fused to gluthathione S-transferase (GST-c-Jun (1-169)) and 27-kDa heat shock protein (hsp27). MonoQ fractionation of cell extracts resolved phosphotransferase activity peaks toward MBP, GST-c-Jun (1-169), and hsp27, which contained MAPK, SAPK/JNK, and MAPKAPK2, respectively, as indicated by immunoblotting data. In RAW 264.7 macrophages, LPS stimulation of MAPKAPK2, a substrate of p38 HOG1 and MAPK, appeared to occur predominantly via p38 HOG1 and not the MAPK. PMA, which activated the MAPK as potently as LPS, did not strongly activate MAPKAPK2, as assessed by hsp27 phosphorylation. Consistent with p38 HOG1-mediating LPS activation of MAPKAPK2, treatment with LPS, but not PMA, increased the tyrosine phosphorylation of p38 HOG1, a modification known to elevate the enzymatic capacity of this kinase. In LPS-treated cells, the activity of SAPK/JNK was increased 5- to 10-fold, as measured by precipitating SAPK/JNK with Abs or immobilized GST-c-Jun and performing an in vitro kinase assay. In addition, the kinases thought to be upstream of SAPK/JNK, SAPK/ERK kinase 1 (SEK1), and MAPK/ERK kinase kinase 1 (MEKK1), were activated following LPS, but not PMA, exposure (5-fold and 2.5-fold, respectively.
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PMID:Activation of multiple proline-directed kinases by bacterial lipopolysaccharide in murine macrophages. 866 21

Rat glutathione transferase P (GST-P) is expressed at low levels in the normal liver but becomes highly expressed in hyperplastic nodules and in hepatocellular carcinomas during chemical hepatocarcinogenesis. To understand the regulation mechanisms of this gene, we have characterized the 5'-flanking region and have found that GST-P gene is regulated by at least two elements: one is a strong enhancer and the other is a silencer. GST-P enhancer I (GPEI), located at -2.5 Kb, consists of two TPA-responsive element (TRE)-like sequences that are palindromically oriented with 3 bp in between. It is well known that TRE is activated by two nuclear oncogenes, c-Jun and c-Fos. Although GPEI is trans-activated by these oncogenes, it is also active in F9 embryonal carcinoma cells that lack c-Jun protein, suggesting that it can function with some trans-activator other than AP-1 (c-Jun/c-Fos heterodimer). Indeed, another protein is identified from the F9 nuclear extract. We have also identified a silencer element at 300 bp upstream from the cap site. There are several cis-elements in this region and at least three trans-acting factors bind to these elements. We purified SF-A (silencer factor A) which binds to several regions in this silencer, and determined the partial amino acid sequence. Interestingly, SF-A seemed to be a related protein to NF1 (nuclear factor 1) which is an activator for the transcription and DNA replication. Another factor SF-B (silencer factor B) has been cloned and found to be the same as LIP (liver inhibitory protein) which is a competitor for LAP (liver activator protein), both are from the same gene designated as C/EBP beta. By transfection analysis using GAL4 DNA binding domain we found LIP is not only a competitor but a direct repressor. In the normal liver, another C/EBP family member, C/EBP alpha also acts as a negative regulator, and this expression decreases during hepatocarcinogenesis, resulting in the loss of silencer function. We carried out the carcinogenesis experiments using transgenic rats harboring a chloramphenicol acetyltransferase (CAT) reporter gene with -2900 to + 59 of the GST-P gene. Liver foci and nodules produced by chemical carcinogens were found to express high levels CAT activity by both CAT assay and immunohistochemical study, while normal liver cells did not express any CAT activity. These results demonstrate that the GST-P gene is trans-activated locus-independently during rat hepatocarcinogenesis. Moreover, the similar results were obtained using transgenic rats carrying GPEI-CAT, indicating that GPEI is an important cis-element for activation of GST-P gene during hepatocarcinogenesis.
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PMID:[Regulation mechanism of specific expression of tumor marker gene during carcinogenesis]. 883 Dec 56

Glial cells in the mammalian CNS are subject to environmental stress resulting from a variety of neuro-pathological conditions. In this study, we have examined the activation of a stress signal responsive kinase, i.e., stress-activated protein kinase (SAPK) or c-Jun N-terminal kinase (JNK), in primary cultures of rat brain glial cells (i.e., astrocytes and oligodendrocytes) and an oligodendrocyte progenitor cell line, CG4, in response to cytokines and other stress inducers. JNK/SAPK activity was measured by an immune complex kinase assay using polyclonal anti-JNK antibodies along with GST c-Jun (1-79) as the substrate. Among the cytokines tested, TNF-alpha had the strongest effect on JNK activation followed by TNF-beta in both the glial cell types while a substantial level of kinase activation was observed in response to IL-1 in astrocytes. JNK activation by TNF-alpha in astrocytes, but not in oligodendrocytes, showed a biphasic response. An in-gel kinase assay of cell extracts and immunoprecipitated JNK confirmed the activation of JNK1 in cells treated with TNF-alpha. JNK was also activated by several other stress-inducing factors including. UV light, heat shock, inhibitors of protein synthesis, and mechanical injury. Incubation of cells with bacterial sphingomyelinase and a cell-permeable ceramide stimulated JNK activity, suggesting that the ceramide pathway may play a role in JNK activation, although the time course of activation did not correspond to that of TNF-alpha. The results are discussed in terms of possible roles of JNK activation in signaling for gliosis in astrocytes and as a protective/toxic response in oligodendrocytes.
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PMID:Activation of C-jun N-terminal kinase/stress-activated protein kinase in primary glial cultures. 889 12


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