Search results for " Regulation"
showing 10 items of 3187 documents
Post-Transcriptional Regulation of Human Inducible Nitric-Oxide Synthase Expression by the Jun N-terminal Kinase
2007
Human inducible nitric-oxide synthase (iNOS) expression is regulated both at transcriptional and post-transcriptional levels. In the present study, the effect of Jun N-terminal kinase (JNK) on human iNOS expression was investigated. In A549/8 human alveolar epithelial cells, both the inhibition of JNK by a pharmacological inhibitor anthra[1,9-cd]pyrazol-6(2H)-one1,9-pyrazoloanthrone (SP600125) and small interfering RNA (siRNA)-mediated down-regulation of JNK led to a reduction of iNOS mRNA and protein expression. iNOS promoter activity was not affected by these treatments. Hence, JNK seems to regulate iNOS expression through post-transcriptional mechanisms by stabilizing iNOS mRNA. Our labo…
Response of yeast cells to high glucose involves molecular and physiological differences when compared to other osmostress conditions.
2015
Yeast cells can be affected by several causes of osmotic stress, such as high salt, sorbitol or glucose concentrations. The last condition is particularly interesting during natural processes where this microorganism participates. Response to osmostress requires the HOG (High Osmolarity Glycerol) pathway and several transcription factors, including Hot1, which plays a key role in high glucose concentrations. In this work, we describe how the yeast response to osmotic stress shows differences in accordance with the stress agent responsible for it. Compared with other conditions, under high glucose stress, delocalization of MAPK (Mitogen-Activated Protein Kinase) Hog1 is slower, induction of …
Role of secondary transporters and phosphotransferase systems in glucose transport by Oenococcus oeni.
2011
ABSTRACT Glucose uptake by the heterofermentative lactic acid bacterium Oenococcus oeni B1 was studied at the physiological and gene expression levels. Glucose- or fructose-grown bacteria catalyzed uptake of [ 14 C]glucose over a pH range from pH 4 to 9, with maxima at pHs 5.5 and 7. Uptake occurred in two-step kinetics in a high- and low-affinity reaction. The high-affinity uptake followed Michaelis-Menten kinetics and required energization. It accumulated the radioactivity of glucose by a factor of 55 within the bacteria. A large portion (about 80%) of the uptake of glucose was inhibited by protonophores and ionophores. Uptake of the glucose at neutral pH was not sensitive to degradation …
Virtual team functioning: Modeling the affective and cognitive effects of an emotional management intervention.
2020
Emotional separation and detachment as two distinct dimensions of parent--adolescent relationships
2011
The study examined adolescents’ emotional separation and detachment from parents, analyzing their relations with connectedness and agency, with some aspects of self—other boundary regulation and with problem behavior. The participants were 331 Italian adolescents, aged from 16 to 19 years (mean age = 17.40, SD = 1.14). Separation and detachment were positively related; they were negatively related to connectedness; detachment was also negatively associated to agency. Emotional separation was negatively predicted by empathic concern, perspective-taking and separate self; emotional detachment was negatively predicted by empathic concern and self—other differentiation. Separation negatively p…
Is more competition better? Retail electricity prices and switching rates in the European Union.
2022
The European Union (EU) promotes the liberalization of retail electricity markets to achieve lower prices, diversified offers, greater customer participation, and sustainable consumption behaviours. While retail competition has been a reality in most EU member states, most studies find that retail competition is suitable for large customers, but the evidence on small customers is inconclusive. We analyze data on electricity prices and switching rates in 27 EU member states and the UK from 2000 to 2019. We find that retail competition is associated with lower prices and that the effect of full liberalization is greater than that of partial liberalization.
Neuroglobin, cytoglobin, and myoglobin contribute to hypoxia adaptation of the subterranean mole rat Spalax.
2010
The subterranean mole rat Spalax is an excellent model for studying adaptation of a mammal toward chronic environmental hypoxia. Neuroglobin (Ngb) and cytoglobin (Cygb) are O 2 -binding respiratory proteins and thus candidates for being involved in molecular hypoxia adaptations of Spalax . Ngb is expressed primarily in vertebrate nerves, whereas Cygb is found in extracellular matrix-producing cells and in some neurons. The physiological functions of both proteins are not fully understood but discussed with regard to O 2 supply, the detoxification of reactive oxygen or nitrogen species, and apoptosis protection. Spalax Ngb and Cygb coding sequences are strongly conserved. However, mRNA and …
Production of Norspermidine Contributes to Aminoglycoside Resistance in pmrAB Mutants of Pseudomonas aeruginosa
2019
Emergence of resistance to polymyxins in Pseudomonas aeruginosa is mainly due to mutations in two-components systems, that promote addition of 4-amino-4-deoxy-L-arabinose to the lipopolysaccharide (LPS) through upregulation of operon arnBCADTEF-ugd (arn) expression. Here, we demonstrate that mutations occurring in different domains of histidine kinase PmrB or in response regulator PmrA result in coresistance to aminoglycosides and colistin. All seventeen clinical strains tested exhibiting such a cross-resistance phenotype were found to be pmrAB mutants. As shown by gene deletion experiments, the decreased susceptibility of the mutants to aminoglycosides was independent from operon arn but r…
Tryptophan promotes morphological and physiological differentiation in Streptomyces coelicolor.
2015
The molecular mechanisms regulating tryptophan biosynthesis in actinomycetes are poorly understood; similarly, the possible roles of tryptophan in the differentiation program of microorganism life-cycle are still underexplored. To unveil the possible regulatory effect of this amino acid on gene expression, an integrated study based on quantitative teverse transcription-PCR (qRT-PCR) and proteomic approaches was performed on the actinomycete model Streptomyces coelicolor. Comparative analyses on the microorganism growth in a minimal medium with or without tryptophan supplementation showed that biosynthetic trp gene expression in S. coelicolor is not subjected to a negative regulation by the …
Sponge biosilica formation involves syneresis following polycondensation in vivo.
2011
Syneresis is a process observed during the maturation/aging of silica gels obtained by sol-gel synthesis that results in shrinkage and expulsion of water due to a rearrangement and increase in the number of bridging siloxane bonds. Here we describe how the process of biosilica deposition during spicule ("biosilica" skeleton of the siliceous sponges) formation involves a phase of syneresis that occurs after the enzyme-mediated polycondensation reaction. Primmorphs from the demosponge Suberites domuncula were used to study syneresis and the inhibition of this mechanism. We showed by scanning electron microscopy that spicules added to primmorphs that have been incubated with manganese sulfate …