Biochemical responses

Currently, along with the economic development, the urbanization process has been taking place strongly, putting great pressure on the water supply for urban areas and industrial zones, leading to conflicts, overlapping and obstacles to the water supply management.

4p vibecca 01-10-2024 2 1   Download

The significant alterations were observed in SOD, CAT, GST and AChE activity for both oral and contact exposure pathways. In conclusion, cypermethrin modulated the activities of biomarkers of oxidative stress and altered the level of energy metabolites in the bees.

10p thebadguys 15-01-2022 9 0   Download

Trehalose metabolism is an essential component of the stress response in yeast cells. In this work we show that the products of the principal genes involved in trehalose metabolism in Schizosaccharomyces pombe, tps1+ (coding for trehalose6-P synthase, Tps1p), ntp1+ (encoding neutral trehalase, Ntp1p) and tpp1+ (that codes for trehalose-6-P phosphatase, Tpp1p), interact in vitro with each other and with themselves to form protein complexes. Disruption of the gene tps1+ blocks the activation of the neutral trehalase induced by heat shock but not by osmotic stress.

9p system191 01-06-2013 28 4   Download

The transcription factor serum response factor (SRF) regulates expression of growth factor-dependent genes and muscle-specific genes in vertebrates. Homologous factors regulate differentiation of some ectodermic tissues in invertebrates. To explore the molecular basis of these different physiological functions, the functionality of human, Drosophila melanogaster and Artemia franciscana SRFs in mammalian cells has been compared in this article. D. melanogaster and, to a lesser extend, A.

9p system191 01-06-2013 32 5   Download

Starch defines a semicrystalline polymer made of two different polysaccharide fractions. The A- and B-type crystalline lattices define the distinct structures reported in cereal and tuber starches, respectively. Amylopectin, the major fraction of starch, is thought to be chiefly responsible for this semicrystalline organization while amylose is generally considered as an amorphous polymer with little or no impact on the overall crystalline organization.

11p system191 01-06-2013 45 4   Download

P-glycoprotein (Pgp), a membrane pump often responsible for the multidrug resistance of cancer cells, undergoes conformational changes in the presence of substrates/modulators, or upon ATP depletion, reflected by its enhanced reactivity with the UIC2 monoclonal antibody. When the UIC2-shift was elicited by certain modulators (e.g. cyclosporin A or vinblastine, but not with verapamil or Tween 80), the subsequent binding of other monoclonal anti-Pgp Ig sharing epitopes with UIC2 (e.g. MM12.10) was abolished [Nagy, H., Goda, K., Arceci, R., Cianfriglia, M., ´ Mechetner, E. & Szabo Jr, G.

6p system191 01-06-2013 62 7   Download

The promoter of the early growth response gene (Egr-1) has been described to be activated by ionizing radiation, and it seems to be clear that this process involves di€erent mitogen activated protein (MAP) kinases, dependent on the speci®c cell type examined. However, early steps leading to activation of the corresponding pathways and thus to overexpression of Egr-1 are not well understood.

10p research12 29-04-2013 45 2   Download

Once platelets are activated, the first event tooccur is a rapid change in shape, associated with Ca 2+ /calmodulin-dependent myosin light chain (MLC) phosphorylation and withRhokinase activation. The purpose of this studywas to investigate which is the biochemical pathway that leads to platelet shape change in response to convulxin, a selective GpVI activator, and to verify whether MLC phosphoryla-tion is essential for this process.

7p tumor12 22-04-2013 37 3   Download

Plant lipoxygenases (LOXs) are a class of dioxygenases which display diverse functions in several physiological processes such as growth, development and response to biotic and abiotic stresses.Even though LOXs have been characterized from several plant species, the physiological role of seed LOXs is still unclear.With the aim to better clarify the occurrence of LOXs and their influence on hazelnut seed quality, we carried out the biochemical and molecular characterization of the main LOX isoforms expressed during seed development....

11p tumor12 20-04-2013 34 4   Download

It was shown previously [Riedinger, H. J., van Betteraey-Nikoleit, M & Probst, H. (2002)Eur. J. Biochem.269, 2383–2393] that initiation ofin vivo SV40 DNA replication is reversibly suppressed by hypoxia in a state where viral minichromosomes exhibit a nearly complete set of repli-cation proteins. Reoxygenation triggers fast completion and post-translational modifications.

11p tumor12 20-04-2013 30 2   Download

In Klebsiella pneumoniae, the flavoprotein, NifL regulates NifA mediated transcriptional activation of the N2-fixation (nif) genes in response tomolecular O2and ammonium.We investigated the influence of membrane-bound oxidoreduc-tases on nif-regulation by biochemical analysis of purified NifLandbymonitoringNifA-mediated expressionofnifH¢-¢lacZ reporter fusions in different mutant backgrounds. NifL-bound FAD-cofactor was reduced by NADH only in the presence of a redox-mediator or inside-out vesicles derived from anaerobically grown K.pneumoniaecells,...

12p tumor12 20-04-2013 33 4   Download

Anumber of cellular systems cooperate in redox regulation, providing metabolic responses according to changes in the oxidation (or reduction)of the redox active components of a cell. Key systems of central metabolism, such as the 2-oxo acid dehydrogenase complexes, are important participants in redox regulation, because their function is controlled by the NADH/NAD + ratio and the complex-bound dihydro-lipoate/lipoate ratio.

7p tumor12 20-04-2013 37 4   Download

All higher organisms divide major biochemical steps into different cellular compartments and often use tissue-specific division of metabolism for the same purpose.Such spatial resolution is accompanied with temporal changes of meta-bolite synthesis in response to environmental stimuli or developmental needs.Although analyses of primary and secondary gene products, i.e. transcripts, proteins, and metabolites, regularly do not cope with this spatial and temporal resolution, these gene products are often observed to be highly coregulated forming complex networks....

10p tumor12 20-04-2013 34 2   Download

Four distinct eukaryotic initiation factor 2a(eIF2a)kinases phosphorylate eIF2aat S51and regulateprotein synthesis in response to various environmental stresses. These are the hemin-regulated inhibitor (HRI), the interferon-inducible dsRNA-dependent kinase (PKR), the endoplasmic reticu-lum (ER)-resident kinase (PERK) and the GCN2 protein kinase. Whereas HRI and PKR appear to be restricted to mammalian cells, GCN2 and PERK seem to be widely distributed in eukaryotes.

14p tumor12 20-04-2013 26 4   Download

Ca 2+ and cAMP are ubiquitous second messengers in euk-aryotes and control numerous physiological responses ran-ging fromfertilization to cell death induction 1 . Todistinguish between these different responses, their subtle regulation in time, space and amplitude is needed. Therefore, the char-acterization of the signalling process requires measurement of secondmessengers with tools of precise localization, high dynamic range and as little disturbance of cell physiology as possible.

10p fptmusic 16-04-2013 41 4   Download

Spontaneous oxidation of 3-hydroxykynureine (3-HK), a metabolic inter-mediate of the tryptophan degradation pathway, elicits a remarkable oxida-tive stress response in animal tissues. In the yellow fever mosquito Aedes aegyptithe excess of this toxic metabolic intermediate is efficiently removed by a specific 3-HK transaminase, which converts 3-HK into the more sta-ble compound xanthurenic acid.

10p fptmusic 12-04-2013 39 3   Download

The molecular response to hypoxia stress in aquatic invertebrates remains relatively unknown. In this study, we investigated the response of the Pacific oyster Crassostrea gigasto hypoxia under experimental conditions and focused on the analysis of the differential expression patterns of specific genes associated with hypoxia response. A suppression subtractive hybridiza-tion method was used to identify specific hypoxia up- and downregulated genes, in gills, mantle and digestive gland, after 7–10 days and 24 days of exposure....

18p fptmusic 12-04-2013 48 3   Download

The ciliated protozoanTetrahymenahas a unique apoptosis-like process, which is called programmed nuclear death (PND). During conjugation, the new germinal micro- and somatic macro-nuclei differentiate from a zygotic fertilized nucleus, whereas the old parental macronucleus degenerates, ensuring that only the new macronucleus is responsible for expression of the progeny genotype.

10p fptmusic 12-04-2013 30 1   Download

p38 Mitogen-activated protein kinase alpha (p38 MAPKa) is a member of the MAPK family. It is activated by cellular stresses and has a number of cellular substrates whose coordinated regulation mediates inflammatory responses. In addition, it is a useful anti-inflammatory drug target that has a high specificity for Ser-Pro or Thr-Pro motifs in proteins and contains a number of transcription factors as well as protein kinases in its catalog of known substrates.

15p fptmusic 11-04-2013 42 3   Download

Ultrasensitive responses are common in cellular information transfer because they allow cells to decode extracellular stimuli in an all-or-none manner. Biochemical responses are usually analyzed by fitting the Hill equation, and the estimated Hill coefficient is taken as a measure of sensi-tivity. However, this approach is not appropriate if the response under con-sideration significantly deviates from the best-fit Hill equation.

9p fptmusic 11-04-2013 30 2   Download