scholarly journals Wild-type p53 mediates positive regulation of gene expression through a specific DNA sequence element.

1992 ◽  
Vol 6 (7) ◽  
pp. 1143-1152 ◽  
Author(s):  
G P Zambetti ◽  
J Bargonetti ◽  
K Walker ◽  
C Prives ◽  
A J Levine
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anastasia Ricci ◽  
Sara Orazi ◽  
Federica Biancucci ◽  
Mauro Magnani ◽  
Michele Menotta

AbstractAtaxia telangiectasia (AT) is a rare genetic neurodegenerative disease. To date, there is no available cure for the illness, but the use of glucocorticoids has been shown to alleviate the neurological symptoms associated with AT. While studying the effects of dexamethasone (dex) in AT fibroblasts, by chance we observed that the nucleoplasmic Lamin A/C was affected by the drug. In addition to the structural roles of A-type lamins, Lamin A/C has been shown to play a role in the regulation of gene expression and cell cycle progression, and alterations in the LMNA gene is cause of human diseases called laminopathies. Dex was found to improve the nucleoplasmic accumulation of soluble Lamin A/C and was capable of managing the large chromatin Lamin A/C scaffolds contained complex, thus regulating epigenetics in treated cells. In addition, dex modified the interactions of Lamin A/C with its direct partners lamin associated polypeptide (LAP) 2a, Retinoblastoma 1 (pRB) and E2F Transcription Factor 1 (E2F1), regulating local gene expression dependent on E2F1. These effects were differentially observed in both AT and wild type (WT) cells. To our knowledge, this is the first reported evidence of the role of dex in Lamin A/C dynamics in AT cells, and may represent a new area of research regarding the effects of glucocorticoids on AT. Moreover, future investigations could also be extended to healthy subjects or to other pathologies such as laminopathies since glucocorticoids may have other important effects in these contexts as well.


1990 ◽  
Vol 10 (8) ◽  
pp. 4080-4088
Author(s):  
F Vauti ◽  
P Morandini ◽  
J Blusch ◽  
A Sachse ◽  
W Nellen

We dissected the promoter of the developmentally induced and cyclic AMP-repressed discoidin I gamma gene and identified a sequence element essential for developmental induction. Transfer of the element to an inactive heterologous promoter demonstrated that this sequence is sufficient to confer expression in axenically growing cells and to induce gene activity in development after growth on bacteria. A 16-base-pair sequence within this element was shown to be sufficient for induction in the discoidin promoter context and was used to reactivate different truncated promoter constructs. This led to the localization of an element necessary for down regulation of gene expression by extracellular cyclic AMP.


1990 ◽  
Vol 10 (8) ◽  
pp. 4080-4088 ◽  
Author(s):  
F Vauti ◽  
P Morandini ◽  
J Blusch ◽  
A Sachse ◽  
W Nellen

We dissected the promoter of the developmentally induced and cyclic AMP-repressed discoidin I gamma gene and identified a sequence element essential for developmental induction. Transfer of the element to an inactive heterologous promoter demonstrated that this sequence is sufficient to confer expression in axenically growing cells and to induce gene activity in development after growth on bacteria. A 16-base-pair sequence within this element was shown to be sufficient for induction in the discoidin promoter context and was used to reactivate different truncated promoter constructs. This led to the localization of an element necessary for down regulation of gene expression by extracellular cyclic AMP.


2010 ◽  
Vol 104 (10) ◽  
pp. 709-717 ◽  
Author(s):  
Dániel Töröcsik ◽  
Lajos Széles ◽  
György Paragh ◽  
Zsuzsa Rákosy ◽  
Helga Bárdos ◽  
...  

SummaryFactor XIII subunit A (FXIII-A) is one of the most overrepresented genes that is expressed during the alternative activation of macrophages. Based on its substrate profile and its cellular localisation, FXIII-A is thought to function as an intracellular/intranuclear transglutaminase. Our aim was to find role for the intracellular FXIII-A by comparing the microarray profiles of alternatively activated monocyte-derived macrophages. Microarray analyses of FXIII-A-deficient patients and healthy controls were evaluated, followed by functional clustering of the differentially expressed genes. After a 48-hour differentiation in the presence of interleukin 4 (IL4), 1,017 probes out of the 24,398 expressed in macrophages from FXIII-A- deficient samples were IL4 sensitive, while only 596 probes were IL4 sensitive in wild-type samples. Of these genes, 307 were induced in both the deficient and the wild-type macrophages. Our results revealed that FXIII-A has important role(s) in mediating gene expression changes in macrophages during alternative activation. Functional clustering of the target genes carried out using Cytoscape/BiNGO and Ingenuity Pathways Analysis programs showed that, in the absence of FXIII-A, the most prominent differences are related to immune functions and to wound response. Our findings suggest that functional impairment of macrophages at the level of gene expression regulation plays a role in the wound healing defects of FXIII-A-deficient patients.


2012 ◽  
Vol 78 (16) ◽  
pp. 5699-5707 ◽  
Author(s):  
James Matsunaga ◽  
Mariana L. Coutinho

ABSTRACTLeptospirosis is a potentially deadly zoonotic disease that afflicts humans and animals.Leptospira interrogans, the predominant agent of leptospirosis, encounters diverse conditions as it proceeds through its life cycle, which includes stages inside and outside the host. Unfortunately, the number of genetic tools available for examining the regulation of gene expression inL. interrogansis limited. Consequently, little is known about the genetic circuits that control gene expression inLeptospira. To better understand the regulation of leptospiral gene expression, theL. interrogans kdplocus, encoding homologs of the P-type ATPase KdpABC potassium transporter with their KdpD sensors and KdpE response regulators, was selected for analysis. We showed that akdpEmutation inL. interrogansprevented the increase inkdpABCmRNA levels observed in the wild-typeL. interrogansstrain when external potassium levels were low. To confirm that KdpE was a positive regulator ofkdpABCtranscription, we developed a novel approach for constructing chromosomal genetic fusions to the endogenousbgaL(β-galactosidase) gene of the nonpathogenLeptospira biflexa. We demonstrated positive regulation of akdpA′-bgaLfusion inL. biflexaby theL. interrogansKdpE response regulator. A controllipL32′-bgaLfusion was not regulated by KdpE. These results demonstrate the utility of genetic fusions to thebgaLgene ofL. biflexafor examining leptospiral gene regulation.


Blood ◽  
1994 ◽  
Vol 83 (8) ◽  
pp. 2063-2071 ◽  
Author(s):  
P Lamb ◽  
LV Kessler ◽  
C Suto ◽  
DE Levy ◽  
HM Seidel ◽  
...  

Many cytokines and growth factors trigger rapid changes in gene expression upon binding to their receptors. In many cases, the mechanism by which these changes are affected is unknown. In this report, we show that interleukin-2 (IL-2), IL-3, IL-4, IL-6, leukemia inhibitory factor (LIF), erythropoietin (Epo), and granulocyte- macrophage colony-stimulating factor (GM-CSF) treatment of cells causes rapid activation of DNA-binding activities that recognize a DNA sequence element previously implicated in regulation of gene expression by interferon gamma (IFN gamma). The IL-4-, IL-6-, and GM-CSF-induced complexes can be distinguished from the recently characterized IFN gamma-activated protein p91 on the basis of mobility in polyacrylamide gels, sequence preferences, and lack of reactivity with an anti-p91 antiserum. The IL-4- and GM-CSF-induced complexes react with antiphosphotyrosine antibodies, demonstrating the presence of phosphotyrosine-containing proteins in these DNA-binding complexes. Transcriptional activation of a reporter gene linked to a synthetic IFN gamma-responsive promoter is observed in response to IFN gamma, IL-6, and LIF. These data suggest a pathway by which cytokines induce rapid changes in gene expression.


2019 ◽  
Vol 201 (17) ◽  
Author(s):  
Florian Lamouche ◽  
Anaïs Chaumeret ◽  
Ibtissem Guefrachi ◽  
Quentin Barrière ◽  
Olivier Pierre ◽  
...  

ABSTRACTSoil bacteria called rhizobia trigger the formation of root nodules on legume plants. The rhizobia infect these symbiotic organs and adopt an intracellular lifestyle within the nodule cells, where they differentiate into nitrogen-fixing bacteroids. Several legume lineages force their symbionts into an extreme cellular differentiation, comprising cell enlargement and genome endoreduplication. The antimicrobial peptide transporter BclA is a major determinant of this process inBradyrhizobiumsp. strain ORS285, a symbiont ofAeschynomenespp. In the absence of BclA, the bacteria proceed until the intracellular infection of nodule cells, but they cannot differentiate into enlarged polyploid and functional bacteroids. Thus, thebclAnodule bacteria constitute an intermediate stage between the free-living soil bacteria and the nitrogen-fixing bacteroids. Metabolomics on whole nodules ofAeschynomene afrasperaandAeschynomene indicainfected with the wild type or thebclAmutant revealed 47 metabolites that differentially accumulated concomitantly with bacteroid differentiation. Bacterial transcriptome analysis of these nodules demonstrated that the intracellular settling of the rhizobia in the symbiotic nodule cells is accompanied by a first transcriptome switch involving several hundred upregulated and downregulated genes and a second switch accompanying the bacteroid differentiation, involving fewer genes but ones that are expressed to extremely elevated levels. The transcriptomes further suggested a dynamic role for oxygen and redox regulation of gene expression during nodule formation and a nonsymbiotic function of BclA. Together, our data uncover the metabolic and gene expression changes that accompany the transition from intracellular bacteria into differentiated nitrogen-fixing bacteroids.IMPORTANCELegume-rhizobium symbiosis is a major ecological process, fueling the biogeochemical nitrogen cycle with reduced nitrogen. It also represents a promising strategy to reduce the use of chemical nitrogen fertilizers in agriculture, thereby improving its sustainability. This interaction leads to the intracellular accommodation of rhizobia within plant cells of symbiotic organs, where they differentiate into nitrogen-fixing bacteroids. In specific legume clades, this differentiation process requires the bacterial transporter BclA to counteract antimicrobial peptides produced by the host. Transcriptome analysis ofBradyrhizobiumwild-type andbclAmutant bacteria in culture and in symbiosis withAeschynomenehost plants dissected the bacterial transcriptional response in distinct phases and highlighted functions of the transporter in the free-living stage of the bacterial life cycle.


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