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See detailPhosphatidylinositol 3,4,5-trisphosphate modulation in Ship2-deficient mouse embryonic fibroblasts
Blero, D.; Zhang, J.; Pesesse, X. et al

in FEBS Journal (2005), 272

SHIP2, the ubiquitous SH2 domain containing inositol 5-phosphatase, includes a series of protein interacting domains and has the ability to dephosphorylate phosphatidylinositol 3,4,5-trisphosphate [PtdIns ... [more ▼]

SHIP2, the ubiquitous SH2 domain containing inositol 5-phosphatase, includes a series of protein interacting domains and has the ability to dephosphorylate phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] in vitro. The present study, which was undertaken to evaluate the impact of SHIP2 on PtdIns(3,4,5)P3 levels, was performed in a mouse embryonic fibroblast (MEF) model using SHIP2 deficient (– ⁄ –) MEF cells derived from knockout mice. PtdIns(3,4,5)P3 was upregulated in serum stimulated – ⁄ – MEF cells as compared to +⁄+ MEF cells. Although the absence of SHIP2 had no effect on basal PtdIns(3,4,5)P3 levels, we show here that this lipid was significantly upregulated in SHIP2 – ⁄ – cells but only after short-term (i.e. 5–10 min) incubation with serum. The difference in PtdIns(3,4,5)P3 levels in heterozygous fibroblast cells was intermediate between the +⁄+ and the – ⁄ – cells. In our model, insulin-like growth factor-1 stimulation did not show this upregulation. Serum stimulated phosphoinositide 3-kinase (PI 3-kinase) activity appeared to be comparable between +⁄+ and – ⁄ – cells. Moreover, protein kinase B, but not mitogen activated protein kinase activity, was also potentiated in SHIP2 deficient cells stimulated by serum. The upregulation of protein kinase B activity in serum stimulated cells was totally reversed in the presence of the PI 3-kinase inhibitor LY-294002, in both +⁄+ and – ⁄ – cells. Altogether, these data establish a link between SHIP2 and the acute control of PtdIns(3,4,5)P3 levels in intact cells [less ▲]

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See detailPhosphine- and ammonium-functionalized ordered mesoporous carbons as supports for cluster-derived metal nanoparticles
Vidick, Deborah; Léonard, Alexandre ULg; Poleunis, Claude et al

in Catalysis Today (2014), 235

An ordered mesoporous carbon (OMC) was functionalized with ammonium or chelating phosphine ligands. In both cases, the functionalization procedure started by oxidation by nitric acid treatment, followed ... [more ▼]

An ordered mesoporous carbon (OMC) was functionalized with ammonium or chelating phosphine ligands. In both cases, the functionalization procedure started by oxidation by nitric acid treatment, followed by activation of surface carboxylic acid groups with thionyl chloride, then formation of amide bonds with diamines. The pendant amine groups were then either quaternized or further reacted with phosphine. The introduced functions were used as anchors for molecular mixed-metal clusters. These organometallic grafted species could then be thermally transformed into hetero-metallic nanoparticles (NP) embedded within the mesoporous framework. The NP/OMC nanocomposites could find application in hydrogenation, heterogeneous catalysis or as electrodes in fuel cells. [less ▲]

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See detailPhosphoinositide phosphatases in a network of signaling reactions
Blero, D.; Payrastre, B.; Schurmans, Stéphane ULg et al

in Pflügers Archiv : European Journal of Physiology (2007), 455

Phosphoinositide phosphatases dephosphorylate the three positions (D-3, 4 and 5) of the inositol ring of the poly-phosphoinositides. They belong to different families of enzymes. The PtdIns(3,4)P(2) 4 ... [more ▼]

Phosphoinositide phosphatases dephosphorylate the three positions (D-3, 4 and 5) of the inositol ring of the poly-phosphoinositides. They belong to different families of enzymes. The PtdIns(3,4)P(2) 4-phosphatase family, the tumour suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN), SAC1 domain phosphatases and myotubularins belong to the tyrosine protein phosphatases superfamily. They share the presence of a conserved cysteine residue in the consensus CX(5)RT/S. Another family consists of the inositol polyphosphate 5-phosphatase isoenzymes. The importance of these phosphoinositide phosphatases in cell regulation is illustrated by multiple examples of their implications in human diseases such as Lowe syndrome, X-linked myotubular myopathy, cancer, diabetes or bacterial infection [less ▲]

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See detailPhospholipid-Binding And Lecithin-Cholesterol Acyltransferase Activation Properties Of Apolipoprotein-A-I Mutants
Holvoet, P.; Zhao, Za.; Vanloo, B. et al

in Biochemistry (1995), 34(41), 13334-42

Recombinant human apolipoprotein A-I (apo A-I) and three deletion mutants: apo A-I(delta Leu44-Leu126), apo A-I(delta Glu139-Leu170), and apo A-I(delta Ala190-Gln243), purified from the periplasmic space ... [more ▼]

Recombinant human apolipoprotein A-I (apo A-I) and three deletion mutants: apo A-I(delta Leu44-Leu126), apo A-I(delta Glu139-Leu170), and apo A-I(delta Ala190-Gln243), purified from the periplasmic space of Escherichia coli, were studied. The rate of turbidity decrease following mixing of apo A-I(delta Ala190-Gln243) with dimyristoylphosphatidylcholine (DMPC) vesicles at 23 degrees C was 10-fold lower than that of the other apo A-I proteins, confirming that the carboxy-terminal region of apo A-I plays a role in rapid lipid binding. The Stokes radii of reconstituted high-density lipoproteins (rHDL), containing dipalmitoylphosphatidylcholine and cholesterol, were larger for the three apo A-I mutants [6.3 nm for apo A-I(delta Leu44-Leu126), 6.1 nm for apo A-I(delta Glu139-Leu170), and 6.5 nm for apo A-I(delta Ala190-Gln243)] than for intact apo A-I (5.0 nm). The mutant rHDL all contained 4 apo A-I molecules per particle as compared to 2 for intact apo A-I. Circular dichroism measurements revealed 8 alpha-helices per apo A-I molecule, 5 per apo A-I(delta Leu44-Leu126), 6 per apo A-I(delta Glu139-Leu170), and 4 per apo A-I(delta Ala190-Gln243) molecule as compared to predicted values of 8, 5, 6, and 6 alpha-helices, respectively. [less ▲]

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See detailPhospholipids quantification in vegetable oil degumming residues by HPLC-ELSD
Pierart, Céline ULg; Danthine, Sabine ULg; Wathelet, B et al

Poster (2008)

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See detailThe phosphoprotein pp135 is an essential constituent of the fibrillar components of nucleoli and of coiled bodies.
Vandelaer, M.; Thiry, Marc ULg

in Histochemistry & Cell Biology (1998), 110(2), 169-77

We examined the distribution of the silver-stainable phosphoprotein, pp135, within Ehrlich tumor and HEp-2 cells by a postembedding Lowicryl immunogold labeling procedure. Identical labeling patterns were ... [more ▼]

We examined the distribution of the silver-stainable phosphoprotein, pp135, within Ehrlich tumor and HEp-2 cells by a postembedding Lowicryl immunogold labeling procedure. Identical labeling patterns were obtained in both cell types. During interphase, gold particles were found not only over the dense fibrillar component but were also evident over the fibrillar centers of nucleoli. By contrast, the granular component did not display any significant label. When rRNA synthesis was inhibited by actinomycin D, the same labeling was observed in segregated nucleoli; both fibrillar components were labeled. Aside from the nucleolar labeling, label was also consistently present in coiled bodies. During metaphase, label was visualized in silver-stainable material of the nucleolus organizing regions. It thus appears that, unlike the two major silver-stained proteins, nucleolin/C23 and B23, pp135 remains located in all major silver-stainable structures during the whole cell cycle. This finding strongly suggests that pp135 could be the component responsible for in situ silver staining. On the other hand, the maintenance of pp135 in the fibrillar centers throughout the cell cycle, like RNA polymerase I, upstream binding factor, and DNA topoisomerase I, suggests that pp135 could be a component involved in transcription of the rRNA genes. [less ▲]

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See detailLe phosphore est-il un facteur de risque cardiovasculaire?
Krzesinski, Jean-Marie ULg; Cohen, Eric P.

in Réalités Cardiologiques (2009), (255), 33-38

Chez l'insuffisant rénal terminal, le phosphore doit être considéré comme un facteur de risque cardiovasculaire. Chez les patients à fonction rénale normale ou subnormale, il peut être surtout le témoin ... [more ▼]

Chez l'insuffisant rénal terminal, le phosphore doit être considéré comme un facteur de risque cardiovasculaire. Chez les patients à fonction rénale normale ou subnormale, il peut être surtout le témoin de ce risque parce qu'il s'associe souvent à d'autres facteurs de risque d'athérosclérose. Il favorise cependant la rigidité artérielle. Le phosphore étant quantitativement élevé dans une alimentation occidentale fort riche, la relation entre cet ion et le risque cardiovasculaire n'est peut-être qu'indirecte. Pour prouver le rôle direct du phosphore sur le risque cardiovasculaire, il est nécessaire d'initier des études à plus grande échelle, prospectives et contrôlées, en connaissant l'alimentation des patients, leurs traitements et comorbidités et divers paramètres biologiques (lipidiques par exemple) à côté de la phosphorémie à déterminer à jeun. [less ▲]

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See detailPhosphorus availability : influence of soil characteristics and fertilization
Renneson, Malorie ULg

Scientific conference (2013, February 04)

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See detailPhosphorus availability in agricultural soils of Wallonia (Belgium) - A modeling approach
Cobert, Florian ULg; Pourret, Olivier; Renneson, Malorie ULg et al

Poster (2013, August)

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See detailPhosphorus intake in preterm babies and variation of tubular reabsorption for phosphate per liter glomerular filtrate
Battisti, Oreste ULg; Langhendries, J. P.; François, A. et al

in Biology of the Neonate (1992), 61

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See detailPhosphorylated HER-2 tyrosine kinase and Her-2/neu gene amplification as predictive factors of response to trastuzumab in patients with HER-2 overexpressing metastatic breast cancer (MBC).
Giuliani, Rosa; Durbecq, Virginie; Di Leo, Angelo et al

in European Journal of Cancer (2007), 43(4), 725-35

AIM: Trastuzumab (T), a humanised monoclonal antibody against HER-2, is active in HER-2-positive MBC patients. However, nearly 60% of the patients do not benefit from T, stressing the need for additional ... [more ▼]

AIM: Trastuzumab (T), a humanised monoclonal antibody against HER-2, is active in HER-2-positive MBC patients. However, nearly 60% of the patients do not benefit from T, stressing the need for additional predictive markers. The following markers could be implicated in response to T: (1) the magnitude of Her-2 gene amplification; (2) the co-expression of the other HER family receptors, possibly responsible for HER-2 trans-activation; (3) the activated status of HER-2; (4) the activated status of downstream effectors as mitogen-activated protein kinases (MAPKs), p38 and p27. METHODS: Medical files of patients with MBC treated with T either as a single agent or in combination with chemotherapy (CT) were reviewed. HER family members (EGFR, HER-2, HER-3, HER-4), the phosphorylated forms of EGFR (p-EGFR), HER-2 (p-HER-2) and of the downstream effectors were evaluated in the archival tumours. The correlation between clinical outcome and the expression of these markers was investigated. RESULTS: (1) Increasing values of Her-2 amplification were associated with a higher probability of achieving an objective response; (2) no statistical significant correlation between the expression of the HER family receptors was found; (3) p-HER-2 was predictive of response in patients treated with T+CT; (4) a statistically significant correlation between p-ERK 1/2, p-p38 and p-HER-2 emerged, pointing to the activated vertical pathway p-HER-2-->p-MAPKs. CONCLUSIONS: p-HER-2 and the magnitude of Her-2 amplification were predictive of response to T and their role deserves to be analysed in larger and more homogenous T-treated populations such as those from large phase III trials. [less ▲]

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See detailThe phosphorylated pathway of serine biosynthesis is essential both for male gametophyte and embryo development and for root growth in Arabidopsis
Cascales - Miñana, Borja ULg; Muñoz-Bertomeu, J.; Flores-Tornero, M. et al

in Plant Cell (2013), 25(6), 2084-2101

This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity ... [more ▼]

This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA under the control of Pro35S (Pro35S:PSP1). However, this construct, which was poorly expressed in the anther tapetum, did not complement mutant fertility. Microspore development in psp1.1/psp1.1 Pro35S:PSP1 arrested at the polarized stage. The tapetum from these lines displayed delayed and irregular development. The expression of PSP1 in the tapetum at critical stages of microspore development suggests that PSP1 activity in this cell layer is essential in pollen development. In addition to embryo death and male sterility, conditional psp1 mutants displayed a shortroot phenotype, which was reverted in the presence of Ser. A metabolomic study demonstrated that the PPSB plays a crucial role in plant metabolism by affecting glycolysis, the tricarboxylic acid cycle, and the biosynthesis of amino acids. We provide evidence of the crucial role of the PPSB in embryo, pollen, and root development and suggest that this pathway is an important link connecting primary metabolism with development. © 2013 American Society of Plant Biologists. All rights reserved. [less ▲]

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See detailThe phosphorylated pathway of serine biosynthesis: a forgotten minor pathway with an essential function in plants
Ros, Roc; Cascales - Miñana, Borja ULg; Toujani, Walid et al

Conference (2012, June)

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See detailPhosphorylated Thiamine Derivatives and Cortical Activity in the Baboon Papio Papio: Effect of Intermittent Light Stimulation
Bettendorff, Lucien ULg; Schoffeniels, Ernest; Naquet, R. et al

in Journal of Neurochemistry (1989), 53(1), 80-87

The effect of intermittent light stimulation (ILS) on the distribution of thiamine derivatives in three brain areas (occipital, motor, and premotor) was compared in photosensitive and nonphotosensitive ... [more ▼]

The effect of intermittent light stimulation (ILS) on the distribution of thiamine derivatives in three brain areas (occipital, motor, and premotor) was compared in photosensitive and nonphotosensitive baboons. ILS induces paroxysmal discharges in the motor and premotor areas of photosensitive animals only. In baboons submitted to ILS, thiamine triphosphate (TTP) decreases in both photosensitive and nonphotosensitive animals; thiamine monophosphate (TMP) increases in photosensitive animals, which present ILS-induced paroxysmal discharges, whereas it is unaffected in nonphotosensitive animals. The variations are the most significant in the occipital (visual) cortex. A consumption of TTP may result from electrical activity induced by light stimulation in the occipital area. No correlation between ILS-induced paroxysmal activity and a decrease in TTP contents was found. However, photosensitive animals are affected differently from nonphotosensitive animals, as their content of TMP in the cerebral cortex increases on stimulation. However, as long as the exact role of thiamine compounds in relation to membrane excitability in the nervous system remains unknown, it is impossible to conclude whether the differences observed in the metabolism of thiamine compounds are the cause or the consequence of the photosensitivity in the baboon Papio papio. [less ▲]

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See detailPhosphorylation At Ser244 By Ck1 Determines Nuclear Localization And Substrate Targeting Of Pkd2
Von Blume, J.; Knippschild, U.; Dequiedt, Franck ULg et al

in Embo Journal (2007), 26(22),

Protein kinase D2 (PKD2), a member of the PKD family of serine/threonine kinases, is localized in various subcellular compartments including the nucleus where the kinase accumulates upon activation of G ... [more ▼]

Protein kinase D2 (PKD2), a member of the PKD family of serine/threonine kinases, is localized in various subcellular compartments including the nucleus where the kinase accumulates upon activation of G-protein-coupled receptors. We define three critical post-translational modifications required for nuclear accumulation of PKD2 in response to activation of the CCK2 receptor (CCK2R): phosphorylation at Ser706 and Ser710 within the activation loop by PKC eta leading to catalytic activity and phosphorylation at Ser244 within the zinc-finger domain, which is crucial for blocking nuclear export of active PKD2 by preventing its interaction with the Crm-1 export machinery. We identify CK1delta and epsilon as upstream activated kinases by CCK2R that phosphorylate PKD2 at Ser244. Moreover, nuclear accumulation of active PKD2 is a prerequisite for efficient phosphorylation of its nuclear substrate, HDAC7. Only nuclear, active PKD2 mediates CCK2R-induced HDAC7 phosphorylation and Nur77 expression. Thus, we define a novel, compartment-specific signal transduction pathway downstream of CCK2R that phosphorylates PKD2 at three specific sites, results in nuclear accumulation of the active kinase and culminates in efficient phosphorylation of nuclear PKD2 substrates in human gastric cancer cells. [less ▲]

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See detailPhosphorylation of bovine leukemia virus Tax protein is required for in vitro transformation but not for transactivation.
Willems, Luc ULg; Grimonpont, Cathy; Kerkhofs, Pierre et al

in Oncogene (1998), 16(17), 2165-76

The Tax proteins of the oncovirinae viruses are phosphorylated transcriptional activators that exhibit oncogenic potential. The role of phosphorylation in their functional activities remains unknown. As a ... [more ▼]

The Tax proteins of the oncovirinae viruses are phosphorylated transcriptional activators that exhibit oncogenic potential. The role of phosphorylation in their functional activities remains unknown. As a model for the Human T-cell leukemia virus type I (HTLV-I), Bovine Leukemia Virus (BLV) permits the characterization of viral replication and leukemogenesis in vivo. Here, we show that the BLV Tax protein is phosphorylated on serine residues 106 and 293 both in insect and in mammalian cells. These sites can also be efficiently phosphorylated by the cdc2 and MAP kinases in vitro. Mutation of these residues does not affect the capacity of the Tax protein to function as a transactivator. Indeed, the Tax proteins mutated at one or both serines increase LTR-directed viral transcription at levels similar to those obtained with wild-type Tax in cell culture. Moreover, inhibition of Tax phosphorylation by W7, a calmodulin antagonist, does not alter its transactivation activity. Thus, phosphorylation on serines 106 and 293 is not required for transactivation by Tax. However, simultaneous substitution of both serines into alanine residues destroys the capacity of Tax to cooperate with the Ha-ras oncogene to transform primary rat embryo fibroblasts and induce tumors in nude mice. When the serines were replaced with aspartic acid residues, the oncogenic potential of Tax was maintained indicating that the negative charge rather than the phosphate group itself was required for Tax oncogenicity. Finally, to assess the role of the serine residues in vivo, recombinant viruses which express the Tax mutants were constructed and injected into sheep. It appeared that the mutated proviruses replicate at levels similar to the wild-type virus in vivo. We conclude that Tax phosphorylation is dispensable for transactivation and viral replication in vivo but is required for its oncogenic potential in vitro. [less ▲]

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See detailPhosphorylation Of Histone Deacetylase 7 By Protein Kinase D Mediates T Cell Receptor-Induced Nur77 Expression And Apoptosis
Dequiedt, Franck ULg; Van Lint, J.; Lecomte, E. et al

in Journal of Experimental Medicine (2005), 201(5),

Detailed reference viewed: 14 (4 ULg)