Search results for " phosphatase"
showing 10 items of 329 documents
Molecular characterization and evolution of the protein phosphatase 2A B' regulatory subunit family in plants.
2002
Abstract Type 2A serine/threonine protein phosphatases (PP2A) are important components in the reversible protein phosphorylation events in plants and other organisms. PP2A proteins are oligomeric complexes constituted by a catalytic subunit and several regulatory subunits that modulate the activity of these phosphatases. The analysis of the complete genome of Arabidopsis allowed us to characterize four novel genes, AtB′ε, AtB′ζ,AtB′η, and AtB′θ, belonging to the PP2A B′ regulatory subunit family. Because four genes of this type had been described previously, this family is composed of eight members. Reverse transcriptase-polymerase chain reaction experiments showed thatAtB′ε mRNAs are prese…
Humoral responses during wound healing in Holothuria tubulosa (Gmelin, 1788)
2021
Abstract Wounds in living organisms trigger tissue-repair mechanisms. The sea cucumber (Holoturia tubulosa) is an excellent model species for achieving a better understanding of the humoral and cellular aspects involved in such healing processes. Consequently, this study assesses data on its morphometric, physiological and humoral responses 1, 2, 6, 24 and 48h after wound induction. In particular, morphometric data on the weight, width, length and coelomic-fluid volume of the species were estimated at different times during our experiments. In addition, the humoral aspects related to the enzymatic activity of esterase, alkaline phosphatase and peroxidase, as well as the cytotoxic activity o…
Amorphous Ca2+ polyphosphate nanoparticles regulate the ATP level in bone-like SaOS-2 cells
2015
ABSTRACT Polyphosphate (polyP) is a physiologically occurring polyanion that is synthesized especially in bone-forming osteoblast cells and blood platelets. We used amorphous polyP nanoparticles, complexed with Ca2+, that have a globular size of ∼100 nm. Because polyP comprises inorganic orthophosphate units that are linked together through high-energy phosphoanhydride bonds, we questioned whether the observed morphogenetic effect, elicited by polyP, is correlated with the energy-generating machinery within the cells. We show that exposure of SaOS-2 osteoblast-like cells to polyP results in a strong accumulation of mitochondria and a parallel translocation of the polyP-degrading enzyme alka…
Investigations on the Mechanism of Induction of the Alkaline Phosphatase by Bromodesoxyuridine in Herpes simplex Virus Transformed Cells and the Tran…
1980
Addition of BrdUrd in combination with prednisolone to HSVi-transformed hamster embryo cells induces an alkaline phosphatase (AP). FdUrd enhances, dThd reduces the inducing capacity of BrdUrd and prednisolone. Induction is prevented by addition of cycloheximide or of cytosine arabinoside. BrdUrd reduces transport and phosphorylation of exogenously applied labeled Urd, especially the amount of UTP, UDP and Urd-diphosphate sugars. The Lineweaver-Burk-plot of uridine-uptake after addition of BrdUrd reveales the characteristics of the mixed type inhibition (competitive-noncompetitive).
Phospholipidosis and down-regulation of the PI3-K/PDK-1/Akt signalling pathway are vitamin E inhibitable events associated with 7-ketocholesterol-ind…
2007
International audience; Among the oxysterols accumulating in atherosclerotic plaque, 7-ketocholesterol (7KC) is a potent apoptotic inducer, which favours myelin figure formation and polar lipid accumulation. This investigation performed on U937 cells consisted in characterizing the myelin figure formation process; determining the effects of 7KC on the PI3-K/PDK-1/Akt signalling pathway; evaluating the activities of vitamin E (Vit-E) (α-tocopherol) on the formation of myelin figures and the PI3-K/PDK-1/Akt signalling pathway and assessing the effects of PI3-K inhibitors (LY-294002, 3-methyladenine) on the activity of Vit-E on cell death and polar lipid accumulation. The ultrastructural and b…
Extracorporeal shock wave-mediated changes in proliferation, differentiation, and gene expression of human osteoblasts.
2008
The goal of this study was to determine whether cell proliferation, differentiation, and gene expression of primary human osteoblasts (hOB) are influenced by shock wave application (SWA).Osteoblast cultures were isolated from cancellous bone fragments and treated with 500 impulses of energy flux densities of 0.06 mJ/mm, 0.18 mJ/mm, 0.36 mJ/mm, and 0.50 mJ/mm. Twenty-four hours and 96 hours after SWA cell proliferation, alkaline phosphatase activity, and mineralization were analyzed. The global gene expression profiling was determined 96 hours after SWA employing Affymetrix HG-U133A microarrays.After 24 hours, hOB showed a dose-dependent increase in cell proliferation from 68.7% (at 0.06 mJ/…
Glucocorticoids inhibit MAP kinase via increased expression and decreased degradation of MKP-1
2001
Glucocorticoids inhibit the proinflammatory activities of transcription factors such as AP-1 and NF-kappa B as well as that of diverse cellular signaling molecules. One of these signaling molecules is the extracellular signal-regulated kinase (Erk-1/2) that controls the release of allergic mediators and the induction of proinflammatory cytokine gene expression in mast cells. The mechanism of inhibition of Erk-1/2 activity by glucocorticoids is unknown. Here we report a novel dual action of glucocorticoids for this inhibition. Glucocorticoids increase the expression of the MAP kinase phosphatase-1 (MKP-1) gene at the promoter level, and attenuate proteasomal degradation of MKP-1, which we re…
Disulfide stress: a novel type of oxidative stress in acute pancreatitis.
2013
Glutathione oxidation and protein glutathionylation are considered hallmarks of oxidative stress in cells because they reflect thiol redox status in proteins. Our aims were to analyze the redox status of thiols and to identify mixed disulfides and targets of redox signaling in pancreas in experimental acute pancreatitis as a model of acute inflammation associated with glutathione depletion. Glutathione depletion in pancreas in acute pancreatitis is not associated with any increase in oxidized glutathione levels or protein glutathionylation. Cystine and homocystine levels as well as protein cysteinylation and γ-glutamyl cysteinylation markedly rose in pancreas after induction of pancreatitis…
Critical Structural Defects Explain Filamin A Mutations Causing Mitral Valve Dysplasia
2019
Mitral valve diseases affect approximately 3% of the population and are the most common reasons for valvular surgery because no drug-based treatments exist. Inheritable genetic mutations have now been established as the cause of mitral valve insufficiency, and four different missense mutations in the filamin A gene (FLNA) have been found in patients suffering from non-syndromic mitral valve dysplasia (MVD). The FLNA protein is expressed, in particular, in endocardial endothelia during fetal valve morphogenesis and is key in cardiac development. The FLNA-MVD causing mutations are clustered in the N-terminal region of FLNA. How the mutations in FLNA modify its structure and function, have mos…
Different protein turnover of interleukin-6-type cytokine signalling components.
1999
Interleukin (IL)-6 and IL-6-type cytokines signal through the gp130/Jak/STAT signal transduction pathway. The key components involved are the signal transducing receptor subunit gp130, the Janus kinases Jak1, Jak2 and Tyk2, STAT1 and STAT3 of the family of signal transducers and activators of transcription, the protein tyrosine phosphatase SHP2 and the suppressors of cytokine signalling SOCS1, SOCS2 and SOCS3. Whereas considerable information has been accumulated concerning the time-course of activation for the individual signalling molecules, data on the availability of the proteins involved in IL-6-type cytokine signal transduction are scarce. Nevertheless, availability of these molecules…