Search results for "repression"
showing 10 items of 92 documents
Habituation and Sensitization Processes in Depressive Disorders
1999
The aim of the present study was to investigate further into habituation and sensitization processes in depressive disorders. The depressive subjects were 27 outpatients. All of them were diagnosed according to DSM-III-R criteria. Controls were 27 normal subjects. The amplitudes of electrodermal responses and the basal levels were recorded during a stimuli series of 15 80-dB tones and of 1 100-dB tone in the 11th trial. The depressive patients displayed lower basal conductance levels and lower conductance amplitudes in orienting responses to the first stimulus and to stimulus change. No differences were found in conductance response amplitudes of stimuli series, although a tendency towards …
The Fumarate/Succinate Antiporter DcuB of Escherichia coli Is a Bifunctional Protein with Sites for Regulation of DcuS-dependent Gene Expression
2008
DcuB of Escherichia coli catalyzes C4-dicarboxylate/succinate antiport during growth by fumarate respiration. The expression of genes of fumarate respiration, including the genes for DcuB (dcuB) and fumarate reductase (frdABCD) is transcriptionally activated by C4-dicarboxylates via the DcuS-DcuR two-component system, comprising the sensor kinase DcuS, which contains a periplasmic sensing domain for C4-dicarboxylates. Deletion or inactivation of dcuB caused constitutive expression of DcuS-regulated genes in the absence of C4-dicarboxylates. The effect was specific for DcuB and not observed after inactivation of the homologous DcuA or the more distantly related DcuC transporter. Random and s…
The down-regulation of miR-125b in chronic lymphocytic leukemias leads to metabolic adaptation of cells to a transformed state
2012
AbstractMiR-125b-1 maps at 11q24, a chromosomal region close to the epicenter of 11q23 deletions in chronic lymphocytic leukemias (CLLs). Our results establish that both aggressive and indolent CLL patients show reduced expression of miR-125b. Overexpression of miR-125b in CLL-derived cell lines resulted in the repression of many transcripts encoding enzymes implicated in cell metabolism. Metabolomics analyses showed that miR-125b overexpression modulated glucose, glutathione, lipid, and glycerolipid metabolism. Changes on the same metabolic pathways also were observed in CLLs. We furthermore analyzed the expression of some of miR-125b–target transcripts that are potentially involved in the…
Regulation of IL-12 p40 Promoter Activity in Primary Human Monocytes: Roles of NF-κB, CCAAT/Enhancer-Binding Protein β, and PU.1 and Identification o…
2001
Abstract Appropriate regulation of IL-12 expression is critical for cell-mediated immune responses. In the present study, we have analyzed the regulation of IL-12 p40 promoter activity in primary human monocytes in vivo. Accordingly, we analyzed the p40 promoter by in vivo footprinting in resting and activated primary human blood CD14+ monocytes. Interestingly, footprints at binding sites for trans-activating proteins such as C/EBP, NF-κB, and ETS were only found upon stimulation with LPS and IFN-γ. In contrast, a footprint over a purine-rich sequence at −155, termed GA-12 (GATA sequence in the IL-12 promoter), was observed in resting, but not activated, cells. Further characterization of t…
Targeting MYCN in Pediatric and Adult Cancers
2021
The deregulation of theMYCfamily of oncogenes, includingc-MYC,MYCNandMYCLoccurs in many types of cancers, and is frequently associated with a poor prognosis. The majority of functional studies have focused onc-MYCdue to its broad expression profile in human cancers. The existence of highly conserved functional domains betweenMYCNandc-MYCsuggests thatMYCNparticipates in similar activities.MYCencodes a basic helix-loop-helix-leucine zipper (bHLH-LZ) transcription factor (TF) whose central oncogenic role in many human cancers makes it a highly desirable therapeutic target. Historically, as a TF, MYC has been regarded as “undruggable”. Thus, recent efforts focus on investigating methods to indi…
Abdominal-A mediated repression of Cyclin E expression during cell-fate specification in the Drosophila central nervous system
2009
Homeotic/Hox genes are known to specify a given developmental pathway by regulating the expression of downstream effector genes. During embryonic CNS development of Drosophila, the Hox protein Abdominal-A (AbdA) is required for the specification of the abdominal NB6-4 lineage. It does so by down regulating the expression of the cell cycle regulator gene Dcyclin E (CycE). CycE is normally expressed in the thoracic NB6-4 lineage to give rise to mixed lineage of neurons and glia, while only glial cells are produced from the abdominal NB6-4 lineage due to the repression of CycE by AbdA. Here we investigate how AbdA represses the expression of CycE to define the abdominal fate of a single NB6-4 …
Engineering of a Promoter Repressed by a Light-Regulated Transcription Factor in Escherichia coli
2021
Light-regulated gene expression systems allow controlling gene expression in space and time with high accuracy. Contrary to previous synthetic light sensors that incorporate two-component systems which require localization at the plasma membrane, soluble one-component repression systems provide several advantageous characteristics. Firstly, they are soluble and able to diffuse across the cytoplasm. Secondly, they are smaller and of lower complexity, enabling less taxing expression and optimization of fewer parts. Thirdly, repression through steric hindrance is a widespread regulation mechanism that does not require specific interaction with host factors, potentially enabling implementation…
Down-regulation of early sea urchin histone H2A gene relies on cis regulative sequences located in the 5' and 3' regions and including the enhancer b…
2004
The tandem repeated sea urchin alpha-histone genes are developmentally regulated by gene-specific promoter elements. Coordinate transcription of the five genes begins after meiotic maturation of the oocyte, continues through cleavage, and reaches its maximum at morula stage, after which these genes are shut off and maintained in a silenced state for the life cycle of the animal. Although cis regulative sequences affecting the timing and the level of expression of these genes have been characterized, much less is known about the mechanism of their repression. Here we report the results of a functional analysis that allowed the identification of the sequence elements needed for the silencing …
«ESTERMINARE DALLE BOTTEGHE DE’ LIBRAI I LIBRI» CIRCOLAZIONE LIBRARIA E CENSURA BORBONICA IN SICILIA NEL ‘700
2014
In Sicilia nel XVIII secolo si assiste all’innalzamento della soglia di attenzione rivolta ai libri stampati nel regno e a quelli di importazione. Il controllo censorio è ora saldamente nelle mani del governo borbonico, soprattutto dopo l’abolizione dell’Inquisizione e negli anni cruciali della repressione antigiacobina. L’attenzione censoria è rivolta ai libri dei feudisti ostili alla corona e favorevoli alle prerogative baronali, più che alla produzione filosofica e libertina d’oltralpe. In un panorama contraddistinto dalla progressiva ed esorbitante presenza della censura e dell’ampliamento delle sue prerogative, che confluiscono man mano entro l’alveo delle competenze della polizia, è d…