Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using the 3T3-F442A preadipocyte line as a model of GH-dependent differentiation, early changes in the DNA-binding affinity of transcription factors in response to GH addition were investigated. Addition of 50 ng/ml human GH to cells in chemically defined medium led to a rapid increase in binding activity of activator protein 1 (AP-1) and CCAAT enhancer-binding protein (C/EBP), which was significant at 30 min and reached maximal induction by 2 h (3-fold for AP-1, 2.5-fold for C/EBP). Induction in AP-1 DNA binding correlates with a concomitant GH trans-activation of c-jun and c-fos genes described previously. Using specific antibodies in electrophoretic mobility shift assays and Western blots, it was shown that the increase in activity of C/EBP is the result of an increase in synthesis of two alternatively translated forms of C/EBP beta: 40-C/EBP beta and 23-C/EBP beta. This increase in protein was not accompanied by alteration in mRNA level and could be blocked by a Janus kinase 2 tyrosine kinase inhibitor and a C kinase inhibitor at concentrations shown to inhibit GH-dependent activation of microtubule-associated protein (MAP) kinases. Concomitant with the translationally activated increase in C/EBP beta, a GH-dependent increase was observed in C/EBP delta transcription. This was accompanied by an increase in mRNA for C/EBP delta, which was superinduced by cycloheximide and, unlike the increase in C/EBP beta protein, was not observed with insulin. Thus GH exerts its effects on C/EBP isoforms at two levels: transcriptional activation of C/EBP delta and translational activation of C/EBP beta. It is proposed that GH-dependent phosphorylation results in the efficient translation of 40-C/EBP beta and 23-C/EBP beta (the mouse homolog of the inhibitor liver-enriched inhibitory protein), and that together with the induction of C/EBP delta, these may be involved in initiating the adipocyte differentiation program.
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PMID:Early responses of trans-activating factors to growth hormone in preadipocytes: differential regulation of CCAAT enhancer-binding protein-beta (C/EBP beta) and C/EBP delta. 776 Aug 44

We have previously documented that glucocorticoids suppress the proliferation of BDS1 hepatoma cells, a rat epithelial tumor cell line derived from minimal deviation Reuber H35 hepatoma cells. Flow cytometry demonstrated that, after treatment with the synthetic glucocorticoid dexamethasone, the growth of an asynchronous population of BDS1 cells was arrested within one cell cycle which resulted in an accumulation of cells with a G1-G0-like DNA content. Consistent with a glucocorticoid-induced block early in the G1 phase of the cell cycle, propidium iodide flow cytometry revealed that addition of dexamethasone up to 2 h after release from contact inhibition prevented BDS1 hepatoma cells from entering S phase, whereas dexamethasone treatment after 2 h had no effect on the entry of cells into S phase. Moreover, dexamethasone treatment did not prevent BDS1 cells from entering S phase after release from synchronization at the G1-S boundary by a double thymidine block. Analysis of DNA content, [3H]-thymidine incorporation, and autoradiography of [3H]-thymidine-labeled nuclei revealed that, after release from dexamethasone, BDS1 cells synchronously reinitiated cell cycle progression and entered S phase 8 h after hormone withdrawal. Northern blot analysis demonstrated that the level of transcripts encoding the G1 marker genes CYL-1 and CYL-2 G1 cyclins peaked 4 h after dexamethasone withdrawal. Dexamethasone induced a 20-fold increase in the level of c-jun mRNA which was reversed after hormone withdrawal, whereas expression of c-fos transcripts remained at a low level during the time course of hormone treatment and withdrawal. Transient transfections with a collagenase-chloramphenicol acetyltransferase reporter gene showed that dexamethasone inhibited 12-O-tetradecanoylphorbol-13-acetate-inducible, but not basal, AP-1 transcription factor activity. Our results demonstrate that glucocorticoids reversibly induce an early G1 block in cell cycle progression of an epithelial tumor cell line that occurs with a coordinate elevation in the expression of c-jun transcripts.
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PMID:Glucocorticoids reversibly arrest rat hepatoma cell growth by inducing an early G1 block in cell cycle progression. 846 59

Glycogen synthase kinase-3 (GSK3) is implicated in the regulation of several physiological processes, including the control of glycogen and protein synthesis by insulin, modulation of the transcription factors AP-1 and CREB, the specification of cell fate in Drosophila and dorsoventral patterning in Xenopus embryos. GSK3 is inhibited by serine phosphorylation in response to insulin or growth factors and in vitro by either MAP kinase-activated protein (MAPKAP) kinase-1 (also known as p90rsk) or p70 ribosomal S6 kinase (p70S6k). Here we show, however, that agents which prevent the activation of both MAPKAP kinase-1 and p70S6k by insulin in vivo do not block the phosphorylation and inhibition of GSK3. Another insulin-stimulated protein kinase inactivates GSK3 under these conditions, and we demonstrate that it is the product of the proto-oncogene protein kinase B (PKB, also known as Akt/RAC). Like the inhibition of GSK3 (refs 10, 14), the activation of PKB is prevented by inhibitors of phosphatidylinositol (PI) 3-kinase.
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PMID:Inhibition of glycogen synthase kinase-3 by insulin mediated by protein kinase B. 852 13

AP-1 is a collection of dimeric sequence specific, DNA binding, transcriptional activators composed of Jun and Fos subunits. The composition, the level and the activity of AP-1 complexes are regulated in response to extracellular stimuli. An important role in this regulation is played by mitogen-activated protein kinases (MAPKs). The specific roles of three MAPKs, namely ERK, JNK and FRK, in modulation of both the level and activity of AP-1, are discussed.
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PMID:The regulation of AP-1 activity by mitogen-activated protein kinases. 865 Feb 58

Human granulocyte-macrophage colony-stimulating factor (hGM-CSF) activates a set of genes such as c-fos, jun, myc, and early growth response gene 1 (egr-1). Studies on BA/F3 cells that express hGM-CSF receptor (hGMR) showed that two different signaling pathways controlled by distinct regions within the beta subunit are involved in activation of c-fos/c-jun genes and in c-myc, respectively. However, the region(s) of the beta subunit responsible for activation of the egr-1 gene and other regulatory genes has not been identified. We describe here how egr-1 promoter is activated by hGMR through two regions of the beta subunit, with these regions being required for activation of the c-fos promoter. Coexpression of dominant negative (dn) Ras (N17ras) or dn JAK2 almost completely suppressed the activation of egr-1 and c-fos promoters. Deletion analysis of egr-1 promoter showed two cis-acting regions responsible for activation by hGM-CSF or mouse interleukin-3 (mIL-3), one between nucleotide positions (nt) -56 and -116, and the other between nt -235 and -480, which contains tandem repeats of the serum response element (SRE) sites. Similar experiments with the c-fos promoter showed that cis-acting regions containing the SRE/AP-1 sites is sufficient for activation by hGM-CSF. Based on these observations, we propose that signaling pathways activating egr-1 and c-fos promoters are controlled by SRE elements, either through the same or overlapping pathways that involve JAK2 and Ras.
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PMID:Characterization of cis-acting sequences and trans-acting signals regulating early growth response 1 and c-fos promoters through the granulocyte-macrophage colony-stimulating factor receptor in BA/F3 cells. 902 42

Cross-linking of the high affinity IgE receptor (FcepsilonRI) on mast cells induces secretion of cytokines, including interleukin (IL)-2, through transcriptional activation of cytokine genes. Previously, defects in the gene coding for Bruton's tyrosine kinase (Btk) were shown to result in defective cytokine production in mast cells, and thereby mice carrying btk mutations exhibited diminished anaphylactic reactions in response to IgE and antigen. In this study, we provide evidence that the transcription factors involved in the IL-2 gene expression in T cells are also required for maximal activation of the IL-2 gene in FcepsilonRI-stimulated mast cells. Among them, AP-1 (Jun/Fos) and NF-AT were identified as candidate transcription factors that are regulated by Btk. Consistent with our previous data indicating that Btk regulates stress-activated protein kinases, c-Jun N-terminal kinase (JNK), c-Jun and other JNK-regulatable transcription factors are activated by FcepsilonRI cross-linking in a Btk-dependent manner. Further, FcepsilonRI-induced IL-2 gene activation is dependent on c-Jun and a component, SEK1, of its upstream activation pathway. Collectively, these data demonstrate that Btk regulates the transcription of the IL-2 gene through the JNK-regulatable transcription factors in FcepsilonRI-stimulated mast cells.
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PMID:Bruton's tyrosine kinase-mediated interleukin-2 gene activation in mast cells. Dependence on the c-Jun N-terminal kinase activation pathway. 955 77

The effect of L-arginine (L-ARG), a nitric oxide donor, or Nomega-nitro-L-arginine (L-NAME), a nitric oxide synthase inhibitor, on the regulation of kainic acid (KA)-induced proenkephalin (proENK) and prodynorphin (proDYN) mRNA expressions in rat hippocampus was studied. The proENK and proDYN mRNA levels were markedly increased 6 h after KA (10 mg/kg, i.p.) administration. The elevations of both proENK and proDYN mRNA levels induced by KA was effectively inhibited by pre-administration of L-ARG (400 mg/kg, i.p.), but was not affected by pre-treatment with L-NAME (200 mg/kg, i.p.). The blockade of KA-induced proENK and proDYN mRNA levels by the pre-treatment with L-ARG was well correlated with proto-oncoprotein levels, such as c-Fos, Fra-2, FosB, JunD, JunB, and c-Jun, as well as AP-1 and ENKCRE-2 DNA binding activities. The pre-administration with L-NAME further increased KA-induced c-jun and c-fos mRNA levels in addition to their protein product levels, although the pre-treatment with L-NAME did not affect KA-induced FosB, Fra-2, JunB, and JunD protein levels at 6 h after treatment. In addition, the pre-administration with L-NAME further increased the KA-induced AP-1 and ENKCRE-2 DNA binding activities. Our results suggest that L-ARG plays an important role in inhibiting KA-induced proENK or proDYN mRNA expression, and its inhibitory action may be mediated through reducing the proto-oncoprotein levels, such as c-Fos, Fra-2, FosB, c-Jun, JunD, and JunB. In addition, L-NAME potentiated the c-Fos or c-Jun gene expression, as well as AP-1 or ENKCRE-2 DNA binding activity. However, these increases did not show the potentiative effect on KA-induced increases of proENK and proDYN mRNA level.
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PMID:The modulatory role of nitric oxide in the regulation of proenkephalin and prodynorphin gene expressions induced by kainic acid in rat hippocampus. 960 69

Activity of the c-jun N-terminal kinase (JNK) has been shown in hematopoietic cells transformed by p210 BCR-ABL. However, analysis has not been reported for hematopoietic cells on the consequences of this activity for c-jun promoter regulation within its distinctive proximal 8-base consensus CRE-like element, an element linked to JNK-mediated increase in c-jun transcription. In the present study, regulation of the proximal c-jun promoter was studied in murine myeloid cells transformed by p210 BCR-ABL. Promoter regulation in p210 BCR-ABL transformed cells was compared with regulation of the promoter in nontransformed interleukin-3 (IL-3)-dependent parental cells. The composition of nuclear AP-1 proteins contained within cells with p210 BCR-ABL, and their binding to the c-jun promoter proximal CRE-like element, was compared with the composition and binding of AP-1 proteins in IL-3-treated parental cells without p210 BCR-ABL. The present analysis found fivefold increased c-jun transcription occurring in p210 BCR-ABL transformed murine myeloid cells possessing a corresponding magnitude of increased kinase activity of JNK, compared with IL-3-stimulated parental cells. Augmented JNK activity was accompanied by increased nuclear abundance of c-jun and c-fos proteins that bound specifically to the proximal c-jun promoter CRE element. Also, representative human leukemic cell lines expressing p210 BCR-ABL and possessing abundant kinase activity of JNK, when compared with parental cells that were deficient in JNK activity, had increased c-jun and c-fos proteins. Finally, to show the relevance of these observations in model systems, we studied blast cells from patients with Philadelphia chromosome-positive acute leukemic transformation, and observed comparable activities of JNK catalysis and c-jun/AP-1 protein relative to the cell lines that possessed p210 BCR-ABL and JNK activity. These studies provide a basis for investigating the set of downstream genes which augmented c-jun/AP-1 activity enlists in the process of transformation by p210 BCR-ABL.
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PMID:Regulation of the c-jun gene in p210 BCR-ABL transformed cells corresponds with activity of JNK, the c-jun N-terminal kinase. 974 85

p21ras is activated by the T cell antigen receptor (TCR) and then co-ordinates important signaling pathways for T lymphocyte activation. Effector pathways for this guanine nucleotide binding protein in T cells are mediated by the serine/threonine kinase Raf-1 and the Ras-related GTPase Rac-1. In fibroblasts, an important effector for the Ras oncogene is Phosphatidylinositol 3-kinase (PtdIns 3-kinase). Activation of this lipid kinase is able to induce critical Rac-1 signaling pathways and can couple p21ras to cell survival mechanisms via the serine/threonine kinase Akt/PKB. The role of PtdIns 3-kinase in Ras signaling in T cells has not been explored. In the present study, we examined the ability of PtdIns 3-kinase to initiate the Rac-1 signaling pathways important for T cell activation. We also examined the possibility that Akt/PKB is regulated by Ras signaling pathways in T lymphocytes. The results show that Ras can initiate a Rac-1 mediated pathway that regulates the transcriptional function of AP-1 complexes. PtdIns 3-kinase signals cannot mimic p21ras and induce the Rac mediated responses of AP-1 transcriptional activation. Moreover, neither TCR or Ras activation of AP-1 is dependent on PtdIns 3-kinase. PKB is activated in response to triggering of the T cell antigen receptor; PtdIns 3-kinase activity is both required and sufficient for this TCR response. In contrast, p21ras signals are unable to induce Akt/PKB activity in T cell nor is Ras function required for Akt/PKB activation in response to the TCR. The present data thus highlight that PtdIns 3-kinase and Akt/PKB are not universal Ras effector molecules. Ras can initiate Rac-1 regulated signaling pathways in the context of T cell antigen receptor function independently of PtdIns 3-kinase activity.
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PMID:p21ras initiates Rac-1 but not phosphatidyl inositol 3 kinase/PKB, mediated signaling pathways in T lymphocytes. 979 2

Oestrogens regulate the expression of genes both positively and negatively in a range of cell types. These effects are mediated via the oestrogen receptor (ER) and involve direct interactions between the ER and DNA response elements, as well as interactions between the ER and other nuclear proteins. We have examined the potential of the ERalpha to regulate the expression of reporter genes under the control of oestrogen response elements (EREs), NFkappaB response elements (NREs) or AP-1/TPA response elements (TREs) in HeLa cells and in human embryonic kidney (HEK-293) cells. Transiently transfected ERalpha was able to activate expression of beta-galactosidase under the control of EREs in an oestradiol (E2)-dependent manner in both HeLa and HEK-293 cells. The ERalpha was able to repress by 80% the TNF-mediated expression of beta-galactosidase under the control of NREs in an E2-dependent manner in HeLa cells but not in HEK-293 cells. ERalpha/E2 also induced a two-fold potentiation of TPA-mediated expression of beta-galactosidase under the control of TREs in HeLa cells but not in HEK-293 cells. These results suggest that the ERalpha is capable of regulating gene expression in a cell-specific manner. We further investigated the mechanisms by which the ERalpha regulates gene expression in these systems by co-expressing the ERalpha and the reporter gene constructs with known cofactors of the ERalpha. We have shown that expression of steroid receptor coactivator-1 alpha (SRC-1alpha) and receptor interacting protein-140 (RIP-140) have no effect on the capacity of the ERalpha to modulate NFkappaB reporter gene activity in HeLa cells. Furthermore, the expression of SRC-1alpha or RIP-140 does not enable the ERalpha to repress NFkappaB or to potentiate an AP-1 response in HEK-293 cells. This suggests that factors other than SRC-1alpha or RIP-140 are responsible for the cell-specific effects seen with ERalpha.
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PMID:The oestrogen receptor regulates NFkappaB and AP-1 activity in a cell-specific manner. 987 7


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