Search results for "Promoter"
showing 10 items of 584 documents
The dnaK operon of Streptomyces coelicolor encodes a novel heat-shock protein which binds to the promoter region of the operon
1995
Transcriptional studies have demonstrated that the dnaK gene of Streptomyces coelicolor A3(2) is contained within a 4.3 kb operon. The operon is transcribed from a single (transiently) heat-inducible promoter, dnaKp, that resembles the typical vegetative (sigma 70-recognized) eubacterial consensus promoter sequence. dnaK transcription was found to be heat-inducible at all stages of development in surface-grown cultures. In addition, at the normal growth temperature of 30 degrees C, dnaK transcript levels were shown to vary at different stages of development, being more abundant in young germinating cultures and in mycelium undergoing sporogenesis. The nucleotide sequence of the dnaK operon …
Generation and characterization of tTS-H4: a novel transcriptional repressor that is compatible with the reverse tetracycline-controlled TET-ON system
2007
Background Conditional gene regulatory systems ensuring tight and adjustable expression of therapeutic genes are central for developing future gene therapy strategies. Among various regulatory systems, tetracycline-controlled gene expression has emerged as a safe and reliable option. Moreover, the tightness of tetracycline-regulated gene switches can be substantially improved by complementing transcriptional activators with antagonizing repressors. Methods To develop novel tetracycline-responsive transcriptional repressors, we fused various transcriptional silencing domains to the TetR (B/E) DNA-binding and dimerization domain of the Tn10-encoded tetracycline resistance operon (TetR (B/E)).…
Regulation ofMUC1Expression in Human Mammary Cell Lines by the c-ErbB2 and Ras Signaling Pathways
2001
The MUC1 protein is a highly O-glycosylated transmembrane molecule that is expressed at the luminal surface of most glandular epithelial cells and is upregulated in carcinomas. Here, we report the effect of the activation of the c-ErbB2 --Ras pathway on the expression of the MUC1 gene in the nontumorigenic mammary cell lines MTSV1-7 and HB2 and in the malignant cell lines T47D and ZR75. Endogenous levels of MUC1 mRNA and protein in HB2 clones permanently overexpressing c-ErbB2 or V12-H-Ras were markedly reduced compared with levels in the parental cell lines. Furthermore, in transient transfection assays, the transcription of a CAT reporter construct driven by the MUC1 promoter was inhibite…
Transcriptional Mechanisms of Proneural Factors and REST in Regulating Neuronal Reprogramming of Astrocytes
2015
Summary Direct lineage reprogramming induces dramatic shifts in cellular identity, employing poorly understood mechanisms. Recently, we demonstrated that expression of Neurog2 or Ascl1 in postnatal mouse astrocytes generates glutamatergic or GABAergic neurons. Here, we take advantage of this model to study dynamics of neuronal cell fate acquisition at the transcriptional level. We found that Neurog2 and Ascl1 rapidly elicited distinct neurogenic programs with only a small subset of shared target genes. Within this subset, only NeuroD4 could by itself induce neuronal reprogramming in both mouse and human astrocytes, while co-expression with Insm1 was required for glutamatergic maturation. Cu…
Genome-wide analysis of factors regulating gene expression in liver
2007
In recent decades, multiple individual genes have been studied with respect to their level of expression in liver tissue and in many cases substantial progress has been made in identifying individual factors promoting gene expression in liver. However, the overall picture is still undefined and general rules or factors regulating gene expression in liver have not yet been established. Thus, a genome-wide screen for factors regulating gene expression in liver is of high interest, as it may reveal common regulatory mechanisms for most genes highly expressed in liver. These factors represent potential new targets in liver disease associated with differential gene expression. Using a novel bioi…
New insights into the regulatory mechanisms of ppGpp and DksA on Escherichia coli RNA polymerase-promoter complex
2015
The stringent response modulators, guanosine tetraphosphate (ppGpp) and protein DksA, bind RNA polymerase (RNAP) and regulate gene expression to adapt bacteria to different environmental conditions. Here, we use Atomic Force Microscopy and in vitro transcription assays to study the effects of these modulators on the conformation and stability of the open promoter complex (RPo) formed at the rrnA P1, rrnB P1, its discriminator (dis) variant and lambda pR promoters. In the absence of modulators, RPo formed at these promoters show different extents of DNA wrapping which correlate with the position of UP elements. Addition of the modulators affects both DNA wrapping and RPo stability in a promo…
The Kelch protein NS1-BP interacts with alpha-enolase/MBP-1 and is involved in c-Myc gene transcriptional control
2007
Alpha-enolase is a key glycolytic enzyme that plays a functional role in several physiological processes depending on the cellular localization. The enzyme is mainly localized in the cytoplasm whereas an alternative translated form, named MBP-1, is predominantly nuclear. The MBP-1 protein has been characterized as a c-Myc promoter binding protein that negatively controls transcription. In the present study, we identified the kelch protein NS1-BP as one of the alpha-enolase/MBP-1 partners by using a yeast two-hybrid screening. Although NS1-BP has been originally described as a protein mainly localized in the nucleus, we provide evidence that NS1-BP also interacts with actin in human cells, a…
Estrogens increase transcription of the human endothelial NO synthase gene: analysis of the transcription factors involved.
1998
Abstract —Estrogens have been found to reduce the incidence of cardiovascular disease that has been ascribed in part to an increased expression and/or activity of the vasoprotective endothelial NO synthase (NOS III). Some reports have shown that the level of expression of this constitutive enzyme can be upregulated by estrogens. The current study investigates the molecular mechanism of the NOS III upregulation in human endothelial EA.hy 926 cells. Incubation of EA.hy 926 cells with 17β-estradiol or the more stable 17α-ethinyl estradiol enhanced NOS III mRNA and protein expression up to 1.8-fold, without changing the stability of the NOS III mRNA. There was no enhancement of NOS III mRNA af…
Regulation of stress response in Oenococcus oeni as a function of environmental changes and growth phase
2000
International audience; Oenococcus oeni is a lactic acid bacterium which is able to grow in wine and perform malolactic fermentation. To survive and grow in such a harsh environment as wine, O. oeni uses several mechanisms of resistance including stress protein synthesis. The molecular characterisation of three stress genes hsp18, clpX, trxA encoding for a small heat shock protein, an ATPase regulation component of ClpP protease and a thioredoxin, respectively, allow us to suggest the existence in O. oeni of multiple regulation mechanisms as is the case in Bacillus subtilis. One common feature of these genes is that they are expressed under the control of housekeeping promoters. The express…
Pharmacological genome demethylation increases radiosensitivity of head and neck squamous carcinoma cells
2011
Aberrant inactivation of tumor suppressor genes by promoter hypermethylation has been recognized as a crucial step of tumor development and is related to aggressiveness and therapy resistance. To identify potential novel treatment strategies, we evaluated pharmacological genome demethylation for the increase of irradiation treatment effectiveness in head and neck squamous cell carcinoma (HNSCC) in this in vitro study. HNSCC cells were cultured with 2 different concentrations of 5-azacytidine (5-Aza) for 72 h, followed by a single fraction irradiation with 4 or 50 Gy, respectively. To show successful genome demethylation, the methylation status of the tumor suppressor gene hic1 (hypermethyla…