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)

Chemically induced differentiation of Friend murine erythroleukemia cells (F-MELC) is a multistep process with a latent period of about 12 h preceding irreversible commitment to terminal maturation. To gain understanding of the early genetic response of F-MELC to the dimethyl sulfoxide (DMSO) inducer of F-MELC differentiation, we have investigated by Northern blot analysis the expression of fos and jun family genes that encode components of the transcription factor AP-1 complex. Our results show that c-jun mRNA is not detected at any time in untreated and DMSO-treated F-MELC. In contrast, DMSO-induced differentiation of F-MELC is associated with an early and transient induction of c-fos and junB mRNAs by 2 to 8 h treatment while in presence of dexamethasone, an inhibitor of F-MELC commitment, c-fos mRNA is not detected and junB mRNA remains at basal levels. junD mRNA is detected at low levels in untreated F-MELC and remains unchanged during DMSO treatment. Furthermore, DMSO treatment in a F-MELC cell line resistant to DMSO-differentiation does not result in an early induction of c-fos and junB mRNAs. Taken together, these results indicate that the DMSO-induced F-MELC differentiation is accompanied by an early co-induction of c-fos and junB during the latent period preceding the commitment to erythroid maturation.
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PMID:Co-induction of c-fos and junB during the latent period preceding commitment of Friend erythroleukemia cells to differentiation. 151 4

Laminin, a basement membrane glycoprotein, has diverse biological activities including cell adhesion, growth, and differentiation. However, little is known concerning the signal transduction and active site involved in cell growth. In this study, we have shown that laminin and a 19-mer peptide (PA22-2) from the carboxyl-terminal end of the long arm of the laminin A chain, which was previously shown to promote cell adhesion and neurite outgrowth, stimulate thymidine incorporation and cell growth of PC12 cells. Laminin and PA22-2 (PA) were also found to induce a rapid and transient mRNA expression of c-fos and c-jun protooncogenes in PC12 cells. Further, both laminin and PA stimulated the DNA binding activity of c-Fos and c-Jun protein complex to the AP-1 site. We have also found that there is a correlation between cell growth, c-fos expression, and the ability of cell attachment to laminin or to PA in different cell types. These results suggest that the PA sequence is a potent site in laminin for both signal transduction and cell growth.
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PMID:Signaling site of laminin with mitogenic activity. 153 19

In HeLa cells transcription of the c-jun gene is activated strongly and rapidly by ultraviolet (UV) irradiation and, to a somewhat lesser extent, by treatment with phorbol ester tumor promoters. In the same cells UV and phorbol esters only marginally enhance the abundance of RNA transcribed from the jun D gene and from the gene coding for the serum response factor (which in turn acts on the UV and phorbol ester response element of the c-fos gene). In contrast to c-jun, jun B transcription is induced more efficiently by phorbol ester than by UV irradiation, suggesting that the members of the jun family are differently regulated. The promoter of c-jun carries two enhancer elements resembling AP-1 binding sites: the jun1 UV response element (URE-71 TGACATCA -64) and the jun2 URE (-190 TTACCTCA-183). These elements act independently in the UV induced expression of c-jun. In the context of the complete c-jun promoter they seem not to be required for c-jun induction by phorbol esters. When fused to the Herpes simplex thymidine kinase promoter, however, the isolated elements mediate induction by both UV and phorbol esters. UV and phorbol ester treatment of cells increases the binding of transcription factors to both elements. Both elements bind factors different in modification or/and constitution from AP-1, the heterodimeric transcription factor composed of c-Fos and c-Jun that controls the activity of the UV and phorbol ester response element (-72 TGAGTCA-66) of the human collagenase gene.
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PMID:Ultraviolet-radiation induced c-jun gene transcription: two AP-1 like binding sites mediate the response. 156 Dec 39

We have compared the mechanisms of the transcriptional induction of c-fos in mouse epidermal cells JB6 (clone 30) by an extracellular burst of active oxygen of the type produced by inflammatory phagocytes to induction by serum and phorbol ester. All three inducers elicit a characteristic immediate early response of c-fos which is inhibited by the protein kinase inhibitor H7 but enhanced by the protein synthesis inhibitor cycloheximide. Experiments with stable transfectants containing fos 5' upstream regulatory sequences linked to an HSV-tk-chloram-phenicol-acetyl-transferase reporter construct indicate that the joint dyad symmetry element-AP-1 motifs exert the most potent enhancer effect in response to active oxygen as well as serum. It is concluded that the different signal transduction pathways used by these inducers converge to the same 5' regulatory sequences of c-fos. In contrast to these common features only active oxygen induction of c-fos required the poly-ADP-ribosylation of chromosomal proteins. The inhibitors of ADP-ribose transferase benzamide and 3-amino-benzamide suppressed the elongation of the c-fos message and the de novo synthesis of nuclear factors, among them c-Fos and c-Jun, which bind to the fos-AP-1 motif in vitro only following stimulation with active oxygen. No active oxygen-induced change was observed in the protein complex which binds to an oligonucleotide containing the SIF and dyad symmetry element motifs in vitro. The presence of Fos and Jun proteins was detected in this complex. Only active oxygen, but not serum or phorbol ester, induces DNA breakage. We propose that poly-ADP-ribosylation is required because it participates in the repair of DNA breaks which interfere with transcription. We observed that Fos protein is weakly poly-ADP-ribosylated in response to active oxygen, but the functional role of this modification remains unclear.
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PMID:Mechanism of c-fos induction by active oxygen. 161 71

Treatment of sensitive EL4 mouse thymoma cells with phorbol esters causes growth inhibition, adherence to substrate and production of several lymphokines including Interleukin 2. Resistant cells lack all of these responses. Since production of Interleukin 2 mRNA is dependent on protein synthesis, and the Interleukin 2 gene has a phorbol ester responsive element, we examined both cell lines for expression of the various Jun and Fos species which bind to this element. Phorbol ester induced c-fos, jun-B, and jun-D RNAs within 20 min in both cell lines. Fos-B was similarly induced in sensitive cells but induction was delayed and greatly enhanced in resistant cells. C-jun RNA induction was detected only in sensitive cells. Western analysis confirmed the induction of c-Jun and a Fos-related protein in sensitive cells only. Southern analysis indicated that both cell lines contain c-jun and fra-1 genes. These results suggest that defective induction of c-Jun and/or Fos-related proteins may contribute to the absence of phorbol ester-induced lymphokine production in resistant EL4 cells.
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PMID:Defective induction of Jun and Fos-related proteins in phorbol ester-resistant EL4 mouse thymoma cells. 171 62

Embryonic stem (ES) cells were used to investigate the target cell specificity and consequences of c-fos when expressed ectopically during embryonic development. Chimeric mice generated with different ES cell clones selected for high exogenous c-fos expression were not affected during embryonic development; however, a high frequency of cartilage tumours developed as early as 3-4 weeks of age apparently independent of the extent of chimerism. The tumours originated from cartilagenous tissues and contained many chondrocytes. Expression of exogenous c-fos RNA and Fos protein was observed during development but was highest in tumour tissues, predominantly in differentiating chondrocytes. A number of primary and clonal tumour-derived cell lines were established which expressed high levels of c-fos, c-jun as well as the cartilage-specific gene type II collagen and which gave rise to cartilage tumours in vivo, some of which also contained bone. Interestingly, the levels of c-Fos and c-Jun appeared to be coordinately regulated in the cell lines as well as in chimeric tissues. Thus, we demonstrate that chondrogenic cells and earlier progenitors are specially transformed by Fos/Jun and therefore represent a novel mesenchymal target cell for c-fos overexpression.
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PMID:A novel target cell for c-fos-induced oncogenesis: development of chondrogenic tumours in embryonic stem cell chimeras. 171 76

Neuronal stimulation can rapidly activate several immediate early genes that code for transcription factors. We have used primary cortical cultures to study the regulation of four of these genes, c-fos, c-jun, jun-B, and zif268. Immunocytochemical studies with antibodies to Jun-B, c-Jun, and c-Fos demonstrate intense staining in the nuclei of a subset of cortical neurons in mature cultures (21-25 days in vitro) but not young cultures (3-7 days in vitro). To assess whether this immunoreactivity may be induced by spontaneous synaptic activity that develops with a similar profile, we examined the effects of agents that reduce this synaptic activity. Tetrodotoxin or N-methyl-D-aspartate receptor antagonists suppress basal immunoreactivity to Jun-B and c-Fos, but not c-Jun, indicating that the basal level of c-Jun expression is not dependent on electrical activity. Picrotoxin, an agent that increases synaptic excitation indirectly by blocking inhibitory synaptic currents mediated by gamma-aminobutyric acidA receptors, markedly increases the percentage of neurons displaying immunoreactivity to c-Fos, c-Jun, Jun-B, and Zif268. Northern analysis suggests that the increases in immunostaining induced by picrotoxin are secondary to a rapid increase in mRNA for these proteins. These findings provide evidence for rapid transcriptional regulation of immediate early genes in cortical neurons by synaptic activity.
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PMID:Synaptic regulation of immediate early gene expression in primary cultures of cortical neurons. 171 31

We have investigated the role of the two AP-1 sites, located at approximately -150 and -180 bp relative to the transcription start site, in induction of the IL-2 promoter through the TCR/CD3 complex. We show that only the proximal (-150 bp) AP-1 site is functional in vitro, as judged by its ability to bind nuclear proteins from T cells stimulated with Ag or anti-CD3 epsilon. The inducible nuclear proteins binding to this site have the characteristics of AP-1, as judged by their kinetics of induction, the ability to compete and be competed efficiently by a metallothionein AP-1 site oligonucleotide, and their reaction with antibodies to Fos and Jun proteins. Mutations in the proximal AP-1 site greatly diminish or abrogate induction of the IL-2 promoter, indicating that the site is also functional in vivo. Although the distal (-180 bp) AP-1 site is incapable of direct binding to nuclear proteins from activated T cells, a mutation in this site diminishes IL-2 promoter induction, suggesting that this site may also be functional in vivo. Cotransfection of a 5' IL-2-chloramphenicol acetyltransferase plasmid with c-Fos and/or c-Jun enhances the induction of IL-2-chloramphenicol acetyltransferase activity, confirming that the IL-2 promoter contains a functional AP-1 site. Both AP-1 sites may be targets for c-Fos action, as inferred from the results of experiments in which c-Fos was cotransfected with internal deletion mutants of the IL-2 promoter lacking either AP-1 site. Northern analysis indicates that mRNAs for at least six members of the Fos/Jun family (c-fos, fosB, fra-1, c-jun, junB, and junD) are expressed in activated Ar-5 cells; thus the AP-1 sites of the IL-2 promoter may bind different dimeric Fos/Jun complexes at different times after T cell activation, perhaps mediating both positive and negative regulation of the IL-2 promoter.
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PMID:Analysis of the AP-1 sites in the IL-2 promoter. 173 37

Early induction of the mRNAs encoding the c-Fos and c-Jun nuclear proteins was examined in rat brain by in situ hybridization at various timepoints following global forebrain ischemia by the method of four-vessel occlusion. All animals were subjected to 20 min of transient ischemia. This produced a pattern of proto-oncogene activation that was most intense in the granule cells of the dentate gyrus 30 min after ischemia, while the hilar cells in the dentate and the pyramidal cells of the CA3 region in the hippocampus showed a more delayed but robust expression of these immediate early genes at 1 h. The neurons of the CA1 region exhibited a more moderate hybridization signal at 1-2 h postischemia. Very little hybridization signal for either immediate early gene could be detected in animals perfused with fixative immediately following ischemia, suggesting that cellular energy levels may have to be restored to a certain level before efficient de novo mRNA synthesis can occur. In the cerebellum, a similar temporal pattern was observed: the granule cells exhibited a prompt but patchy expression of c-fos and c-jun that was followed by a delayed signal in the Purkinje cells. Without exception c-fos and c-jun appeared to be expressed in unison, although the time course of c-fos and c-jun mRNA accumulation and decay was different in various brain regions: invariably the cerebellum returned rapidly to its baseline with virtually no remaining signal at 3 h postischemia, while c-fos and c-jun activation in the hippocampus remained high at 3 h and returned to baseline by 6 h. Several other brain regions showed early production of c-fos and c-jun mRNAs, such as the medial habenula, piriform cortex, the amygdala, the centromedian, lateral posterior, paracentral, intermediodorsal and reuniens nuclei of the thalamus and the ventromedial and dorsal nuclei of the hypothalamus; in the brainstem, the trapezoid body and the noradrenergic neurons of the locus ceruleus as well as the adrenergic neurons in the ventrolateral medulla (C1 group) and nucleus tractus solitarius (C2 group) regions displayed slightly less intense hybridization signals. In addition, the ependyma of the lateral ventricles and the third ventricle showed a prompt albeit short-lived production of c-fos and c-jun mRNAs. Sham-operated animals as well as animals that had survived to one week postischemia showed either no or only trace levels of hybridization signal.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:In situ hybridization analysis of c-fos and c-jun expression in the rat brain following transient forebrain ischemia. 181 28

We applied Southwestern and Western blotting and gel retardation techniques to investigate the changes that occur in the cyclic adenosine monophosphate (cAMP)-responsive element (CRE) binding (CREB) proteins in rapidly growing, chemically induced 5123tc and 5123D Morris hepatomas. Using the CRE sequences from the c-fos, E2A, and somatostatin gene promoters, we identified in the nuclear proteins from normal unstimulated or proliferating rat liver cells six different protein factors of Mr 34,000, 36,000, 40,000, 47,000, 56,000, and 72,000 capable of binding to the element. The Mr 47,000 protein had the highest specificity for the core CRE, suggesting its importance in cAMP-mediated gene expression. We could not find the Mr 47,000 CREB protein in the 5123tc and 5123D hepatomas. Our efforts to detect this protein in the tumors by (a) using the CRE sequence from different gene promoters, (b) altering the protocol for extracting nuclear proteins, or (c) attempting to restore its DNA-binding property by phosphorylation [with endogenous protein kinase(s), a catalytic subunit of cAMP-dependent protein kinase, and protein kinase C/dephosphorylation (with alkaline phosphatase)] were unsuccessful. The loss of tje Mr 47,000 CREB protein from solid tumors of the Morris hepatoma is likely to be related to the neoplastic properties of the tumor cell rather than to cell growth because the level of this protein remained unchanged during a 6-day period of liver regeneration. The nuclear extract from the Morris hepatoma that did not have the Mr 47,000 CRE-binding factor contained proteins immunologically related to the CREB, c-Jun, and c-Fos proteins. We conclude that the Mr 47,000 factor represents a distinct member of the CRE-binding protein family and that its absence from the hepatomas may lead to aberrant expression of cAMP-inducible genes.
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PMID:Changes in cyclic adenosine monophosphate-responsive element binding proteins in rat hepatomas. 182 83


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