Search results for "DNA-BINDING PROTEIN"
showing 10 items of 449 documents
Tristetraprolin Regulates the Expression of the Human Inducible Nitric-Oxide Synthase Gene
2005
The expression of human inducible NO synthase (iNOS) is regulated both by transcriptional and post-transcriptional mechanisms. Stabilization of mRNAs often depends on activation of p38 mitogen-activated protein kinase (p38 MAPK). In human DLD-1 cells, inhibition of p38 MAPK by the compound 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) or by overexpression of a dominant-negative p38 MAPKalpha protein resulted in a reduction of human iNOS mRNA and protein expression, whereas human iNOS promoter activity was not affected. An important RNA binding protein regulated by the p38 MAPK pathway and involved in the regulation of the stability of several mRNAs is tr…
Diacylglycerols containing Omega 3 and Omega 6 fatty acids bind to RasGRP and modulate MAP kinase activation.
2003
We elucidated the effects of different diacylglycerols (DAGs), i.e. 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG), 1-stearoyl-2-docosahexaenoyl-sn-glycerol (SDG), and 1-stearoyl-2-eicosapentaenoyl-sn-glycerol (SEG), on [3H]PDBu binding to RasGRP. The competition studies with these DAGs on [3H]PDBu binding to RasGRP revealed different Ki values for these DAG molecular species. Furthermore, we transfected human Jurkat T cells by a plasmid containing RasGRP and assessed the implication of endogenous DAGs on activation of MAP kinases ERK1/ERK2, induced by phorbol-12-myristate-13-acetate (PMA). In control cells, GF109203X, a protein kinase C inhibitor, inhibited ERK1/ERK2 activation. However, this…
The Drosophila ACP65A cuticle gene: deletion scanning analysis of cis-regulatory sequences and regulation by DHR38
2005
1526-954X (Print) Journal Article Research Support, Non-U.S. Gov't; The regulatory sequences of the Drosophila ACP65A cuticle gene were analyzed in vivo in transgenic flies, using both fusion genes constructs and transposase-mediated deletions within a P element containing ACP65A regulatory sequences fused to the lacZ gene (deletion scanning). The sequences located between -594 and +161 are sufficient to confer both temporal and spatial expression specificities, indicating the presence of tissue-specific enhancers and response elements to hormone-induced factors. In addition, timing of expression and tissue-specificity appear to be controlled by distinct cis-regulatory elements, which sugge…
Transcriptional regulation of the proton translocating NADH dehydrogenase genes (nuoA-N) of Escherichia coli by electron acceptors, electron donors a…
1995
The promoter region and transcriptional regulation of the nuoA-N gene locus encoding the proton-translocating NADH:quinone oxidoreductase was analysed. A 560 bp intergenic region upstream of the nuo locus was followed by a gene (designated lrhA for LysR homologue A) coding for a gene regulator similar to those of the LysR family. Disruption of lrhA did not affect growth (respiratory or non-respiratory) or expression of nuo significantly. Transcriptional regulation of nuo by electron acceptors, electron donors and the transcriptional regulators ArcA, FNR, NarL and NarP, and by IHF (integration host factor) was studied with protein and operon fusions containing the promoter region up to base …
Induction of interferon regulatory factors, 2′‐5′ oligoadenylate synthetase, P68 kinase and RNase L in chronic myelogenous leukaemia cells and its re…
1996
The genes crucially determining the therapeutic response of chronic myelogenous leukaemia (CML) to interferon-alpha (IFN-alpha) are unknown. Recently, two independent IFN-alpha signalling pathways were identified: the classic pathway mediates induction of 2'-5' oligoadenylate synthetase (2-5 OAS), p68 kinase and IFN regulatory factor-2 (IRF-2), whereas the alternate pathway leads to activation of IFN regulatory factor-1 (IRF-1). We investigated whether deficient or imbalanced expression of components of these two pathways is associated with resistance of CML cells to antiproliferative action of IFN alpha/beta. Constitutive and IFN-induced transcript levels of IFN-dependent genes in mononucl…
Study of the cytolethal distending toxin (CDT)-activated cell cycle checkpoint. Involvement of the CHK2 kinase.
2001
AbstractThe bacterial cytolethal distending toxin (CDT) triggers a G2/M cell cycle arrest in eukaryotic cells by inhibiting the CDC25C phosphatase-dependent CDK1 dephosphorylation and activation. We report that upon CDT treatment CDC25C is fully sequestered in the cytoplasmic compartment, an effect that is reminiscent of DNA damage-dependent checkpoint activation. We show that the checkpoint kinase CHK2, an upstream regulator of CDC25C, is phosphorylated and activated after CDT treatment. In contrast to what is observed with other DNA damaging agents, we demonstrate that the activation of CHK2 can only take place during S-phase. Use of wortmannin and caffeine suggests that this effect is no…
A genome-wide transcriptional study reveals that iron deficiency inhibits the yeast TORC1 pathway
2019
Iron is an essential micronutrient that participates as a cofactor in a broad range of metabolic processes including mitochondrial respiration, DNA replication, protein translation and lipid biosynthesis. Adaptation to iron deficiency requires the global reorganization of cellular metabolism directed to optimize iron utilization. The budding yeast Saccharomyces cerevisiae has been widely used to characterize the responses of eukaryotic microorganisms to iron depletion. In this report, we used a genomic approach to investigate the contribution of transcription rates to the modulation of mRNA levels during adaptation of yeast cells to iron starvation. We reveal that a decrease in the activity…
Yeast Dun1 Kinase Regulates Ribonucleotide Reductase Inhibitor Sml1 in Response to Iron Deficiency
2014
Iron is an essential micronutrient for all eukaryotic organisms because it participates as a redox-active cofactor in many biological processes, including DNA replication and repair. Eukaryotic ribonucleotide reductases (RNRs) are Fe-dependent enzymes that catalyze deoxyribonucleoside diphosphate (dNDP) synthesis. We show here that the levels of the Sml1 protein, a yeast RNR large-subunit inhibitor, specifically decrease in response to both nutritional and genetic Fe deficiencies in a Dun1-dependent but Mec1/Rad53- and Aft1-independent manner. The decline of Sml1 protein levels upon Fe starvation depends on Dun1 forkhead-associated and kinase domains, the 26S proteasome, and the vacuolar pr…
Resistance of keratinocytes to TGFbeta-mediated growth restriction and apoptosis induction accelerates re-epithelialization in skin wounds.
2002
The pleiotropic growth factor TGFβ plays an important role in regulating responses to skin injury. TGFβ targets many different cell types and is involved in all aspects of wound healing entailing inflammation,re-epithelialization, matrix formation and remodeling. To elucidate the role of TGFβ signal transduction in keratinocytes during cutaneous wound healing, we have used transgenic mice expressing a dominant negative type II TGFβ receptor exclusively in keratinocytes. We could demonstrate that this loss of TGFβ signaling in keratinocytes led to an accelerated re-epithelialization of full thickness excisional wounds accompanied by an increased proliferation in keratinocytes at the wound ed…
Leptin: A pivotal mediator of intestinal inflammation in mice
2002
Abstract Background & Aims: In addition to acting as a regulator of food intake and energy expenditure, leptin can also modulate immune and inflammatory responses. The role of leptin in intestinal inflammation is the focus of the present study. Methods: Acute and chronic colitis were induced in leptin-deficient ob/ob or wild-type (WT) mice using dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS). The severity of colitis was evaluated, and possible mechanisms were studied. Results: Leptin directly stimulates intraepithelial lymphocytes (IELs) and lamina propria mononuclear cells (LPMCs). In the DSS acute model, ob/ob mice exhibited a 72% reduction of colitis severity and sp…