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See detailTHE FUNCTION OF HMG-BOX TRANSCRIPTION FACTORS Sox4a AND Sox4b IN ZEBRAFISH BONE DEVELOPMENT AND HOMEOSTASIS.
Aceto, Jessica ULg; Motte, Patrick ULg; Martial, Joseph ULg et al

in Journal of Gravitational Physiology : A Journal of the International Society for Gravitational Physiology (2008), 15

In mammals, the Sox4 gene is involved in development of endocardial crests, the brain, the lung, teeth, gonads and lymphocytes. Recently, Sox4 was shown to control bone mass and mineralization in mice. In ... [more ▼]

In mammals, the Sox4 gene is involved in development of endocardial crests, the brain, the lung, teeth, gonads and lymphocytes. Recently, Sox4 was shown to control bone mass and mineralization in mice. In zebrafish, two homologs for the mammalian Sox4 are present, sox4a and sox4b. Here we investigate the function of the sox4a and sox4b genes in cartilage and bone development in zebrafish. Therefore, we focus our attention on the first bone structures to be formed, the head skeleton and more precisely the pharyngeal cartilage. We show that both genes are expressed in the pharyngeal region, albeit at different time points during development. Double in situ hybridization experiments are used to exactly define the particular tissues where they are expressed. Furthermore, microinjection experiments of antisense oligonucleotides are used to block translation of these specific genes and to define their precise function during cartilage and bone development. [less ▲]

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See detailFunction of Penicillin-binding protein 3 in Streptococcus Faecium
Coyette, Jacques; Somzé, Anne; Briquet, Jean-Jacques et al

in Hakenbeck, Regine; Höltje, Joachim-Volker; Labischinski, Harald (Eds.) The Target Penicillin : the Murein Sacculus of Bacterial Cell Walls Architecture and Growth : Proceedings (1983)

Cefotaxime at concns. around the min. inhibitory concn. (MIC, 5 μM) or below (0.1-1.0 μM) causes transformation of the normal S. faecium cells to bacilliform cells whose length increases with increasing ... [more ▼]

Cefotaxime at concns. around the min. inhibitory concn. (MIC, 5 μM) or below (0.1-1.0 μM) causes transformation of the normal S. faecium cells to bacilliform cells whose length increases with increasing duration of treatment. Septa are initiated but never reach completion. Affinity detn. for cefotaxime binding showed that the antibiotic binds preferentially to the 3 highest mol. wt. penicillin-binding proteins (PBP); PBP-2 and PBP-3 are about 100-fold more sensitive to cefotaxime than PBP-1. It appears, therefore, that PbP-2 and PBP-3 are involved in cell septation. This was confirmed by using cefatoxime in subinhibitory concns. (1 μM). From cell samples collected 30 and 60 min after addn. of cefotaxime, membranes were isolated, labeled with satg. [3H]benzylpenicillin and examd. by fluorog. Under these conditions only PBP-2 and PBP-3 were satd. by cefotaxime. At this stage no distinction could be made between the 2 proteins; either both or 1 of them may be involved in cell division. Cefoxitin produced morphol. alteration of a different nature than cefotaxime. The cefoxitin-treated cells had increased diam. and were slightly elongated. The most striking alteration was the frequent presence of conical poles contrasting with round poles obsd. in control cells. The morphol. alteration obsd. in cefoxitin-treated cells could be attributed to the inhibition of the function of PBP-1, PBP-2, or PBP-3. Elongated cells similar to those obtained with cefotaxime were not found with cefoxitin at concns. sufficient to sat. PBP-2. The main difference between cefotaxime- and cefoxitin-treated cells is that PBP-3 is satd. by cefotaxime but not altered at all by cefoxitin. Thus, septation inhibition must be due to the interaction of cefotaxime with PBP-3 [less ▲]

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See detailFunction of the Chloroplast Hydrogenase in the Microalga Chlamydomonas: The Role of Hydrogenase and State Transitions during Photosynthetic Activation in Anaerobiosis
Ghysels, Bart ULg; Godaux, Damien ULg; Matagne, René-Fernand ULg et al

in PLoS ONE (2013), 8(5), 64161

Like a majority of photosynthetic microorganisms, the green unicellular alga Chlamydomonas reinhardtii may encounter O2 deprived conditions on a regular basis. In response to anaerobiosis or in a ... [more ▼]

Like a majority of photosynthetic microorganisms, the green unicellular alga Chlamydomonas reinhardtii may encounter O2 deprived conditions on a regular basis. In response to anaerobiosis or in a respiration defective context, the photosynthetic electron transport chain of Chlamydomonas is remodeled by a state transition process to a conformation that favours the photoproduction of ATP at the expense of reductant synthesis. In some unicellular green algae including Chlamydomonas, anoxia also triggers the induction of a chloroplast-located, oxygen sensitive hydrogenase, which accepts electrons from reduced ferredoxin to convert protons into molecular hydrogen. Although microalgal hydrogen evolution has received much interest for its biotechnological potential, its physiological role remains unclear. By using specific Chlamydomonas mutants, we demonstrate that the state transition ability and the hydrogenase function are both critical for induction of photosynthesis in anoxia. These two processes are thus important for survival of the cells when they are transiently placed in an anaerobic environment. [less ▲]

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See detailFunction of the chloroplastic NAD(P)H dehydrogenase Nda2 for H(2) photoproduction in sulphur-deprived Chlamydomonas reinhardtii.
Mignolet, Emmanuel; Lecler, Renaud; Ghysels, Bart ULg et al

in Journal of biotechnology (2012), 162(1), 81-8

The relative contributions of the PSII-dependent and Nda2-dependent pathways for H(2) photoproduction were investigated in the green microalga Chlamydomonas reinhardtii after suphur-deprivation. For this ... [more ▼]

The relative contributions of the PSII-dependent and Nda2-dependent pathways for H(2) photoproduction were investigated in the green microalga Chlamydomonas reinhardtii after suphur-deprivation. For this purpose, H(2) gas production was compared for wild-type and Nda2-deficient cells with or without DCMU (a PSII-inhibitor) in the same experimental conditions. Nda2-deficiency caused a 30% decrease of the maximal H(2) photoevolution rate observed shortly after the establishment of anoxia, and an acceleration of the decline of H(2) photoevolution rate with time. DCMU addition to Nda2-deficient cells completely inhibited H(2) photoproduction, showing that the PSII-independent H(2) photoproduction relies on the presence of Nda2, which feeds the photosynthetic electron transport chain with electrons derived from oxidative catabolism. Nda2-protein abundance increased as a result of sulphur deprivation and further during the H(2) photoproduction process, resulting in high rates of non-photochemical plastoquinone reduction in control cells. Nda2-deficiency had no significant effect on photosynthetic and respiratory capacities in sulphur-deprived cells, but caused changes in the cell energetic status (ATP and NADPH/NADP+ ratio). The rapid decline of H(2) photoevolution rate with time in Nda2-deficient cells revealed a more pronounced inhibition of H(2) photoproduction by accumulated H(2) in the absence of non-photochemical plastoquinone reduction. Nda2 is therefore important for linking H(2) photoproduction with catabolism of storage carbon compounds, and seems also involved in regulating the redox poise of the photosynthetic electron transport chain during H(2) photoproduction. [less ▲]

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See detailFunction of the chloroplastic NADP(H) dehydrogenase NDA2 for the H2 photoproduction in sulphur-deprived Chlamydomonas reinhardtii
Mignolet, Emmanuel ULg; Lecler, Renaud ULg; Ghysels, Bart ULg et al

in Journal of Biotechnology (2012), 162

The relative contributions of the PSII-dependent and Nda2-dependent pathways for H2 photoproduction were investigated in the green microalga Chlamydomonas reinhardtii after suphur-deprivation. For this ... [more ▼]

The relative contributions of the PSII-dependent and Nda2-dependent pathways for H2 photoproduction were investigated in the green microalga Chlamydomonas reinhardtii after suphur-deprivation. For this purpose, H2 gas production was compared for wild-type and Nda2-deficient cells with or without DCMU (a PSII-inhibitor) in the same experimental conditions. Nda2-deficiency caused a 30 % decrease of the maximal H2 photoevolution rate observed shortly after the establishment of anoxia, and an acceleration of the decline of H2 photoevolution rate with time. DCMU addition to Nda2-deficient cells completely inhibited H2 photoproduction, showing that the PSII-independent H2 photoproduction relies on the presence of Nda2, which feeds the photosynthetic electron transport chain with electrons derived from oxidative catabolism. Nda2-protein abundance increased as a result of sulphur deprivation and further during the H2 photoproduction process, resulting in high rates of non-photochemical plastoquinone reduction in control cells. Nda2-deficiency had no significant effect on photosynthetic and respiratory capacities in sulphur-deprived cells, but caused changes in the cell energetic status (ATP and NADPH/NADP+ ratio). The rapid decline of H2 photoevolution rate with time in Nda2-deficient cells revealed a more pronounced inhibition of H2 photoproduction by accumulated H2 in the absence of non-photochemical plastoquinone reduction. Nda2 is therefore important for linking H2 photoproduction with catabolism of storage carbon compounds, and seems also involved in regulating the redox poise of the photosynthetic electron transport chain during H2 photoproduction. [less ▲]

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See detailThe function of the transcription factor Egr1 in zebrafish cartilage development
Dalcq, Julia ULg; Pasque, Vincent; Ramos, Sonia Davila et al

in Developmental Biology (2007, June 01), 306(1), 439-440

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See detailFunction, diversity and therapeutic potential of the N-terminal domain of human chemokine receptors
Szpakowska, Martyna ULg; Fievez, Virginie; Arumugan, Karthik et al

in Biochemical Pharmacology (2012)

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See detailFunctional amphiphilic and biodegradable copolymers for intravenous vectorization
Van Butsele, Kathy ULg; Jérôme, Robert ULg; Jérôme, Christine ULg

in Polymer (2007), 48

This paper aims at reporting on the design of polymeric drug nanocarriers used in cancer therapy, with a special emphasis on the control of their biodistribution. First, the prominent role of poly ... [more ▼]

This paper aims at reporting on the design of polymeric drug nanocarriers used in cancer therapy, with a special emphasis on the control of their biodistribution. First, the prominent role of poly(ethylene oxide) in the lifetime of nanocarriers circulating in the blood stream is highlighted, and the origin of a passive targeting based on a difference in the anatomy of tumors and normal tissues is discussed. The main body of the review is devoted to the targeting of nanocarriers towards tumors and the underlying concepts. As a rule, either the constitutive polymer is stimuli-responsive and the locus of drug release is where the stimulation occurs, or a ligand endowed with specific recognition is grafted onto the nanocarrier. Finally, the fate of the nanocarrier after drug delivery and the bioelimination of the polymer(s) involved are briefly considered. [less ▲]

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See detailFunctional amphiphilic and degradable copolymers for drug delivery systems
Freichels, Hélène ULg; Pourcelle, Vincent; Plapied, Laurence et al

Poster (2008, December 18)

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See detailFunctional Analysis and the Finite Element Method
Stainier, Laurent; Tossings, Patricia ULg

Learning material (2008)

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See detailFunctional analysis of an FLC-LIKE gene in root chicory
Périlleux, Claire ULg; Pieltain, Alexandra ULg; D'Aloia, Maria ULg et al

in Comparative Biochemistry and Physiology. Part A, Physiology (2009), 153A(2/Suppl.), 198-199

Vernalization is known to promote flowering in Arabidopsis thaliana by inhibiting the expression of a strong repressor: FLOWERING LOCUS C (FLC). The recent cloning of an FLC-LIKE gene in sugar beet (Beta ... [more ▼]

Vernalization is known to promote flowering in Arabidopsis thaliana by inhibiting the expression of a strong repressor: FLOWERING LOCUS C (FLC). The recent cloning of an FLC-LIKE gene in sugar beet (Beta vulgaris; BvFL1) and – here – in root chicory (Cichorium intybus; CiFL1) suggests the conservation of FLC biological function during evolution of eudicots. Hence physiological questions that remain difficult to address in Arabidopsis can be studied in other species. We investigated the correlation between CiFL1 expression and plant-age dependent responsiveness to vernalization. We also studied the effect of post-vernalization growing temperature, which can stabilize or erase the vernalized state. [less ▲]

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See detailFunctional analysis of hydrogen photoproduction in respiratory-deficient mutants of Chlamydomonas reinhardtii
Lecler, Renaud ULg; Godaux, Damien ULg; Vigeolas, Hélène ULg et al

in International Journal of Hydrogen Energy (2011), 36

In this paper, mitochondrial mutants of Chlamydomonas reinhardtii defective for respiratory complex I (NADH:ubiquinone oxidoreductase), complex III (ubiquinol cytochrome c oxidoreductase) and both ... [more ▼]

In this paper, mitochondrial mutants of Chlamydomonas reinhardtii defective for respiratory complex I (NADH:ubiquinone oxidoreductase), complex III (ubiquinol cytochrome c oxidoreductase) and both complexes I and III were analyzed for H2 photoproduction. Several parameters were followed during the S-deficiency stage and the anaerobic stage leading to H2 photoproduction. At the early aerobic S-deficiency stage, starch and neutral lipids accumulated in all strains but their amount was significantly decreased in mutants compared to wild type. During the H2 photoproduction process, whereas starch content strongly decreased in all strains, neutral lipid amount remained nearly unchanged, suggesting that starch degraded by glycolysis is the preferential substrate for energy production during anaerobiosis. The mutants displayed a decrease in H2 photoproduction correlating to the number of active mitochondrial proton-pumping sites lost in the strains. Our results thus highlight the critical role of oxidative phosphorylation during the first (aerobic) stage of S-starvation when carbon resources are accumulated. [less ▲]

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See detailFunctional analysis of the Antirrhinum floral homeotic DEFICIENS gene in vivo and in vitro by using a temperature-sensitive mutant.
Zachgo, S.; Silva, E de A; Motte, Patrick ULg et al

in Development (1995), 121(9), 2861-75

Flowers of the temperature-sensitive DEFICIENS (DEF) mutant, def-101, display sepaloid petals and carpelloid stamens when grown at 26 degrees C, the non-permissive temperature. In contrast, when ... [more ▼]

Flowers of the temperature-sensitive DEFICIENS (DEF) mutant, def-101, display sepaloid petals and carpelloid stamens when grown at 26 degrees C, the non-permissive temperature. In contrast, when cultivated under permissive conditions at 15 degrees C, the morphology of def-101 flowers resembles that of the wild type. Temperature shift experiments during early and late phases of flower development revealed that second and third whorl organ development is differentially sensitive to changes in DEF expression. In addition, early DEF expression seems to control the spatially correct initiation of fourth whorl organ development. Reduction of the def-101 gene dosage differentially affects organogenesis in adjacent whorls: at the lower temperature development of petals in the second whorl and initiation of carpels in the centre of the flower is not affected while third whorl organogenesis follows the mutant (carpelloid) pattern. The possible contribution of accessory factors to organ-specific DEF functions is discussed. In situ analyses of mRNA and protein expression patterns during def-101 flower development at 15 degrees C and at 26 degrees C support previously proposed combinatorial regulatory interactions between the MADS-box proteins DEF and GLOBOSA (GLO), and provide evidence that the autoregulatory control of DEF and GLO expression by the DEF/GLO heterodimer starts after initiation of all organ primordia. Immunolocalisation revealed that both proteins are located in the nucleus. Interestingly, higher growth temperature affects the stability of both the DEF-101 and GLO proteins in vivo. In vitro DNA binding studies suggest that the temperature sensitivity of the def-101 mutant is due to an altered heterodimerisation/DNA-binding capability of the DEF-101 protein, conditioned by the deletion of one amino acid within the K-box, a protein region thought to be involved in protein-protein interaction. In addition, we introduce a mutant allele of GLO, glo-confusa, where insertion of one amino acid impairs the hydrophobic carboxy-terminal region of the MADS-box, but which confers no strong phenotypic changes to the flower. The strong mutant phenotype of flowers of def-101/glo-conf double mutants when grown in the cold represents genetic evidence for heterodimerisation between DEF and GLO in vivo. The potential to dissect structural and functional domains of MADS-box transcription factors is discussed. [less ▲]

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See detailFunctional analysis of the cell division protein FtsW of Escherichia coli
Pastoret, Soumya; Fraipont, Claudine ULg; den Blaauwen, Tanneke et al

in Journal of Bacteriology (2004), 186(24), 8370-8379

Site-directed mutagenesis experiments combined with fluorescence microscopy shed light on the role of Escherichia coli FtsW, a membrane protein belonging to the SEDS family that is involved in ... [more ▼]

Site-directed mutagenesis experiments combined with fluorescence microscopy shed light on the role of Escherichia coli FtsW, a membrane protein belonging to the SEDS family that is involved in peptidoglycan assembly during cell elongation, division, and sporulation. This essential cell division protein has 10 transmembrane segments (TMSs). It is a late recruit to the division site and is required for subsequent recruitment of penicillin-binding protein 3 (PBP3) catalyzing peptide cross-linking. The results allow identification of several domains of the protein with distinct functions. The localization of PBP3 to the septum was found to be dependent on the periplasmic loop located between TMSs 9 and 10. The E240-A249 amphiphilic peptide in the periplasmic loop between TMSs 7 and 8 appears to be a key element in the functioning of FtsW in the septal peptidoglycan assembly machineries. The intracellular loop (containing the R166-FI78 amphiphilic peptide) between TMSs 4 and 5 and Gly 311 in TMS 8 are important components of the amino acid sequence-folding information. [less ▲]

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See detailThe functional analysis of the Mousterian and Micoquian assemblages of Sesselfelsgrotte, Germany. Tool use and Hafting in the European Late Middle Paleolithic
Rots, Veerle ULg

in Quartär : Jahrbuch für Erforschung des Eiszeitalters und seiner Kulturen (2009), 56

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