Search results for "transcriptional regulation"
showing 10 items of 154 documents
Transcription of heat shock gene loci versus non-heat shock loci in Chironomus polytene chromosomes: evidence for heat-induced formation of novel put…
1995
The heat shock response of Chironomus polytene chromosomes was reexamined. The in vivo effects of heat shock on chromosomal [3H]uridine labeling, RNA polymerase II distribution and ribonucleoprotein (RNP) formation were investigated. One primary result is a clarification of the number and location of chromosomal sites strongly induced by treatment at 37 degrees C for 60 min. In total, seven major heat shock loci were identified by transcription autoradiography in Chironomus tentans: I-20A, II-16B, II-10C, II-4B, II-1C, III-12B, and IV-5C. Secondly, combining immunofluorescence with transcription autoradiography, I find RNA polymerase II occurring after heat shock at multiple chromosomal sit…
Nouvelles perspectives concernant la structure et la fonction du domaine carboxyl terminal de Hfq
2015
Accumulating evidence indicates that RNA metabolism components assemble into supramolecular cellular structures to mediate functional compartmentalization within the cytoplasmic membrane of the bacterial cell. This cellular compartmentalization could play important roles in the processes of RNA degradation and maturation. These components include Hfq, the RNA chaperone protein, which is involved in the post-transcriptional control of protein synthesis mainly by the virtue of its interactions with several small regulatory ncRNAs (sRNA). The Escherichia coli Hfq is structurally organized into two domains. An N-terminal domain that folds as strongly bent β-sheets within individual protomers to…
Expression profiling of autoimmune regulator AIRE mRNA in a comprehensive set of human normal and neoplastic tissues.
2006
Defects in the autoimmune regulator (AIRE) gene cause the monogenic autoimmune disease autoimmune polyendocrinopathy syndrome type 1 (APS-1), which is characterized by a loss of self-tolerance to multiple organs. In concordance with its role in immune tolerance, AIRE is strongly expressed in medullary thymic epithelial cells (mTECs). Data on mechanisms controlling AIRE activation and the expression of this gene in other tissues are fragmentary and controversial. We report here AIRE mRNA expression profiling of a large set of normal human tissues and cells, tumor specimen and methylation deficient cell lines. On this broad data basis we found that AIRE mRNA expression is confined to mTECs in…
Etude de la régulation transcriptionnelle des lymphocytes T CD4 dans un contexte de cancer : application en immunothérapie anticancéreuse
2015
Immune surveillance of tumors is based on the ability of effector cells of the immune system to detect and eliminate the cancer cells. Notwithstanding, the complete and spontaneous regression of established cancers was observed only in very few cases. The failure of cancer resolution by the immune system could result from the combination of several factors: i) inadequate immune response related to a low tumor immunogenicity, ii) incompetent immune system consecutively to induced or acquired immunodeficiencies and iii) the selection of resistant tumor variants able to thwart immune surveillance or subverting immune responses. Developing novel cancer immunotherapy strategies leading to potent…
ID: 156
2015
Innate lymphoid cells (ILCs) are a recently discovered family of innate lymphocytes that are substantially represented at mucosal surfaces and have been implicated in the protection of epithelial barriers. Various types of ILCs can be discriminated based on the expression of distinct transcription factors controlling the expression of a distinct set of cytokine genes endowing the various ILC subsets with a specific range of effector functions. Currently, three groups of ILCs are being recognized. Group 1 ILCs (ILC1s) are a diverse group of ILCs comprised of natural killer (NK) cells and other, poorly defined subsets of ILCs. It is believed that the ILC1 fate decision is controlled by the T-…
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 …
The oxygen-responsive transcriptional regulator FNR ofEscherichia coli : the search for signals and reactions
1997
The FNR (fumarate and nitrate reductase regulation) protein of Escherichia coli is an oxygen-responsive transcriptional regulator required for the switch from aerobic to anaerobic metabolism. In the absence of oxygen, FNR changes from the inactive to the active state. The sensory and the regulatory functions reside in separate domains of FNR. The sensory domain contains a Fe-S cluster, which is of the [4Fe-4S]2+ type under anaerobic conditions. It is suggested that oxygen is supplied to the cytoplasmic FNR by diffusion and inactivates FNR by direct interaction. Reactivation under anoxic conditions requires cellular reductants. In vitro, the Fe-S cluster is converted to a [3Fe-4S]+ or a [2Fe…
Expressional control of the ‘constitutive’ isoforms of nitric oxide synthase (NOS I and NOS III)
1998
Nitric oxide synthase (NOS) exists in three established isoforms. NOS I (NOS1, ncNOS) was originally discovered in neurons. This enzyme and splice variants thereof have since been found in many other cells and tissues. NOS II (NOS2, iNOS) was first identified in murine macrophages, but can also be induced in many other cell types. NOS III (NOS3, ecNOS) is expressed mainly in endothelial cells. Whereas NOS II is a transcriptionally regulated enzyme, NOS I and NOS III are considered constitutively expressed proteins. However, evidence generated in recent years indicates that these two isoforms are also subject to expressional regulation. In view of the important biological functions of these …
Transcriptional regulation of miR-224 upregulated in human HCCs by NFκB inflammatory pathways
2012
Background & Aims: miR-224 is up-regulated in human HCCs as compared to both paired peri-tumoral cirrhotic tissues and cirrhotic livers without HCC. Here, we have cloned the miR-224 regulatory region and characterized its transcriptional regulation by the NFκB-dependent inflammatory pathways. Methods: Mature miRNA expression was evaluated by a 2 step stem-loop real-time RT-PCR. The recruitment of polymerase II and transcription factors on the pre-miR-224 promoter has been assessed by ChIPSeq and ChIP. Results: We found miR-224 levels strongly up-regulated in both peri-tumoral cirrhotic livers and HCC samples as compared to normal livers. In silico analysis of the putative miR-224 promoter r…
A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio. Role of an intronic sequence in transcriptional a…
2004
0962-1075 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between i…