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See detailMolecular characterisation of a versatile peroxidase from a Bjerkandera strain
Moreira, Patricia R.; Duez, Colette ULg; Dehareng, Dominique ULg et al

in Journal of Biotechnology (2005), 118(4), 339-352

The cloning and sequencing of the rbpa gene coding for a versatile peroxidase from a novel Bjerkandera strain is hereby reported. The 1777 bp isolated fragment contained a 1698 bp peroxidase-encoding gene ... [more ▼]

The cloning and sequencing of the rbpa gene coding for a versatile peroxidase from a novel Bjerkandera strain is hereby reported. The 1777 bp isolated fragment contained a 1698 bp peroxidase-encoding gene, interrupted by 11 introns. The 367 amino acid-deduced sequence includes a 27 amino acid-signal peptide. The molecular model, built via homology modelling with crystal structures of four fungal peroxidases, highlighted the amino acid residues putatively involved in manganese binding and aromatic substrate oxidation. The potential heme pocket residues (R44, F47, H48, E79, N85, H177, F194 and D239) include both distal and proximal histidines (H48 and H177). RBP possesses potential calcium-binding residues (D49, G67, D69, S71, S178, D195, T197, I200 and D202) and eight cysteine residues (C3, C15, C16, C35, C121, C250, C286, C316). In addition, RIBP includes residues involved in substrate oxidation: three acidic residues (E37, E41 and D183)-putatively involved in manganese binding and H83 and W172-potentially involved in oxidation of aromatic substrates. Characterisation of nucleotide and amino acid sequences include RBP in versatile peroxidase group sharing catalytic properties of both UP and MnP. In addition, the RBP enzyme appears to be closely related with the ligninolytic peroxidases from the Trametes versicolor strain. (C) 2005 Published by Elsevier B.V. [less ▲]

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See detailMolecular characterization of a specific thiamine triphosphatase widely expressed in mammalian tissues
Lakaye, Bernard ULg; Makarchikov, Alexander F; Antunes, Adelio F et al

in Journal of Biological Chemistry (2002), 277(16), 13771-13777

Thiamine triphosphate (ThTP) is found at low concentrations in most animal tissues, and recent data suggest that it may act as a phosphate donor for the phosphorylation of some proteins. In the mammalian ... [more ▼]

Thiamine triphosphate (ThTP) is found at low concentrations in most animal tissues, and recent data suggest that it may act as a phosphate donor for the phosphorylation of some proteins. In the mammalian brain, ThTP synthesis is rapid, but its steady-state concentration remains low, presumably because of rapid hydrolysis. In this report we purified a soluble thiamine triphosphatase (ThTPase; EC 3.6.1.28) from calf brain. The bovine ThTPase is a 24-kDa monomer, hydrolyzing ThTP with virtually absolute specificity. Partial sequence data obtained from the purified bovine enzyme by tandem mass spectrometry were used to search the GenBank(TM) data base. A significant identity was found with only one human sequence, the hypothetical 230-amino acid protein MGC2652. The coding regions from human and bovine brain mRNA were amplified by reverse transcription-PCR, cloned in Escherichia coli, and sequenced. The human open reading frame was expressed in E. coli as a GST fusion protein. Transformed bacteria had a high isopropyl-beta-D-thiogalactopyranoside-inducible ThTPase activity. The recombinant ThTPase had properties similar to those of human brain ThTPase, and it was specific for ThTP. The mRNA was expressed in most human tissues but at relatively low levels. This is the first report of a molecular characterization of a specific ThTPase. [less ▲]

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See detailMOLECULAR CHARACTERIZATION OF CLOSTRIDIUM DIFFICILE STRAINS FROM ELDERLY CARE HOME RESIDENTS
Rodriguez Diaz, Cristina ULg

Poster (2013, October 11)

Clostridium difficile is the primary cause of nosocomial diarrhoea and pseudomembranous colitis after use of antibiotics. Production of toxins A and B are the main virulence factors responsible for its ... [more ▼]

Clostridium difficile is the primary cause of nosocomial diarrhoea and pseudomembranous colitis after use of antibiotics. Production of toxins A and B are the main virulence factors responsible for its pathogenicity. Increasing age, several co-morbidities, environmental contamination, antibiotic exposure and other intestinal perturbations appear to be the greatest risk factors for C. difficile infection (CDI). Therefore, elderly care home residents are considered particularly vulnerable to CDI. The aim of this study was to evaluate and follow the prevalence of C. difficile in a Belgian nursing home and to characterize the C. difficile strains isolated from faeces of elderly care home residents. [less ▲]

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See detailMolecular characterization of embryogenesis in Phaseolus
Abid, Ghassen ULg

Doctoral thesis (2011)

Chez les végétaux supérieurs, l’embryogenèse est une phase clé du développement au cours de laquelle l’embryon établit les principales structures de la future plante. La compréhension des processus ... [more ▼]

Chez les végétaux supérieurs, l’embryogenèse est une phase clé du développement au cours de laquelle l’embryon établit les principales structures de la future plante. La compréhension des processus moléculaires et physiologiques menant à la formation de la graine est donc d’un intérêt agronomique majeur. Chez Phaseolus la caractérisation moléculaire de l’embryogenèse permet de mieux comprendre les mécanismes du développement embryonnaire et de son dysfonctionnement observé chez les hybrides interspécifiques. Cette thèse s’inscrit dans ce cadre et vise à identifier et caractériser des gènes clés impliqués dans le développement de l'embryon chez Phaseolus. Des hybridations interspécifiques ont été réalisées entre l’espèce P.vulgaris L. (cultivar NI637) utilisée comme parent mâle et l’espèce P. coccineus L. (cultivar NI16) utilisée comme parent femelle. Des analyses ont aussi été effectuées sur un mutant obtenu par mutagenèse chimique à l'EMS (Ethyl Méthyl Sulfonate) de graines de la variété BAT93 de P.vulgaris. Une étude histologique comparative a permis de suivre la dynamique de l’embryogenèse du haricot commun à partir d’embryons prélevés 3 à 12 jours après la pollinisation et provenant de plantes normales et déficients dans la production de graines. Les embryons de P. vulgaris se développent plus rapidement par rapport à ceux issus du mutant EMS. Ces derniers présentent des anomalies au niveau de l’embryon et du suspenseur. La caractérisation fonctionnelle de deux gènes candidats MIPS (myo-inositol phosphate synthase) et Sus (sucrose synthase) a été réalisée par RT-PCR quantitative et hybridation in situ suite à une étude spatio-temporelle d’expression de ces deux gènes candidats au cours de développement embryonnaire chez Phaseolus. L’analyse du profil d’expression de ces deux gènes montre qu’ils sont exprimés différemment au niveau des tissus de l’embryon et du suspenseur. L’analyse in silico nous a permis de sélectionner 22 gènes candidats dont nous avons vérifié l'expression au cours de développement de la graine chez Phaseolus. Des variations au niveau de la méthylation de l’ADN ont été déterminées chez les hybrides interspécifiques comparativement à leurs parents. La technique de l’HSS a permis d’isoler des fragments d’ADNs complémentaires différemment exprimés au cours de développement de la graine chez Phaseolus. L’analyse des séquences de ces ADNs complémentaires montre qu’ils codent pour plusieurs protéines intervenant dans le développement cellulaire et embryonnaire, en particulier le "storage protein activator" (SPA), le "pentatricopeptide repeat-containing protein" (PPR) et l’acetyl-CoA carboxylase (ACCase). La caractérisation de ces différents gènes exprimés au cours du développement de la graine, fournit de nouveaux outils susceptibles de mettre en évidence des mécanismes de dysfonctionnement embryonnaire chez le genre Phaseolus. [less ▲]

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See detailMolecular characterization of geminivirus-derived small RNAs in different plant species.
Akbergenov, Rashid; Si-Ammour, Azeddine; Blevins, Todd et al

in Nucleic acids research (2006), 34(2), 462-71

DNA geminiviruses are thought to be targets of RNA silencing. Here, we characterize small interfering (si) RNAs-the hallmarks of silencing-associated with Cabbage leaf curl begomovirus in Arabidopsis and ... [more ▼]

DNA geminiviruses are thought to be targets of RNA silencing. Here, we characterize small interfering (si) RNAs-the hallmarks of silencing-associated with Cabbage leaf curl begomovirus in Arabidopsis and African cassava mosaic begomovirus in Nicotiana benthamiana and cassava. We detected 21, 22 and 24 nt siRNAs of both polarities, derived from both the coding and the intergenic regions of these geminiviruses. Genetic evidence showed that all the 24 nt and a substantial fraction of the 22 nt viral siRNAs are generated by the dicer-like proteins DCL3 and DCL2, respectively. The viral siRNAs were 5' end phosphorylated, as shown by phosphatase treatments, and methylated at the 3'-nucleotide, as shown by HEN1 miRNA methylase-dependent resistance to beta-elimination. Similar modifications were found in all types of endogenous and transgene-derived siRNAs tested, but not in a major fraction of siRNAs from a cytoplasmic RNA tobamovirus. We conclude that several distinct silencing pathways are involved in DNA virus-plant interactions. [less ▲]

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See detailMolecular characterization of the AMPA-receptor potentiator S70340 in rat primary cortical culture: Whole-genome expression profiling.
Mourlevat, S.; Galizzi, J. P.; Guigal-Stephan, N. et al

in Neuroscience Research (2011), 70

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See detailMolecular characterization of the bovine GHRL gene
Colinet, Frédéric ULg; Portetelle, Daniel ULg; Renaville, Robert ULg

in Archiv für Tierzucht = Archives Animal Breeding (2009), 52(1), 79-84

Bovine ghrelin, a 27 amino acid pepticle, has been identified in oxyntic glands of the abomasum. It is an endogenous ligand for growth hormone secretagogue receptor and stimulates food intake and growth ... [more ▼]

Bovine ghrelin, a 27 amino acid pepticle, has been identified in oxyntic glands of the abomasum. It is an endogenous ligand for growth hormone secretagogue receptor and stimulates food intake and growth hormone secretion. The bovine GHRL gene was completely sequenced and consists of five exons and four introns. Like mouse and human GHRL genes, we found that the bovine GHRL gene also contains a first non-coding exon of 21 bp. The bovine GHRL gene codes for 116 amino acid pepticle named preproghrelin which contains the ghrelin pepticle and another pepticle similar to obestatin. Sequence analysis revealed eight polymorphisms, which are located in the non-coding sequence of the gene. [less ▲]

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See detailMolecular characterization of the caprine (Capra hircus) lymphocyte function-associated antigen-1 alpha subunit
Fett, Thomas ULg; Zecchinon, Laurent ULg; Baise, Etienne ULg et al

in BMC Veterinary Research (2005)

Background: Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alpha L beta 2) is required for many cellular adhesive interactions during the immune response. Results: The Capra hircus CD11a ... [more ▼]

Background: Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alpha L beta 2) is required for many cellular adhesive interactions during the immune response. Results: The Capra hircus CD11a-encoding cDNA was sequenced and compared with its human, murine, rat, bovine and ovine counterparts. Despite some focal differences, it shares all the main characteristics of its known mammalian homologues. Conclusion: Therefore, along with the caprine CD18-encoding cDNA, which has been available for a few months, the sequence data revealed here will allow the Capra hircus LFA-1 expression in vitro as a tool to explore the specificities of inflammation in the caprine species. [less ▲]

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See detailMolecular characterization of the host-pathogen relationships involved during an infection of GF-305 peach trees by the Peach latent mosaic viroid (PLMVd)
Parisi, Olivier ULg

Doctoral thesis (2011)

The Peach latent mosaic viroid (PLMVd) infects peach trees in all production areas. This pathogen is responsible of direct and indirect crop losses. However only a few data are available as regards on one ... [more ▼]

The Peach latent mosaic viroid (PLMVd) infects peach trees in all production areas. This pathogen is responsible of direct and indirect crop losses. However only a few data are available as regards on one hand the determinant of pathogenicity of this viroid and on the other hand the resistance mechanisms of plants against this pathogen. The original approach of this work was to give the foundation of this double characterization. Firstly, the role of the P8 pseudoknot, present in every sequenced PLMVd, was studied by directed mutagenesis. Secondly, the molecular response of different peach trees infected by different variants was evaluated by the use of the cDNA-AFLP. The main objective of this thesis was to identify a metabolic pathway implicated in the plant defence against the PLMVd. In the term of this work, it seemed that the P8 pseudoknot was implicated either in the stability or in the replication of the viroid into the infected cells. Indeed, the inoculated variant (with a destabilized pseudoknot) has shown a reduced replication during the cultural season. In spite of the presence of the mutated variant in the plants, no symptom was observed on the peach tree leaves. However, we cannot conclude if this absence of symptom is due to the low viroid quantity either to an implication of the pseudo-knot in the pathogenicity of the PLMVd. The characterization of the gene expression in the infected peach trees has allowed to highlight that the PLMVd represses genes implicated in the photosynthesis and more specifically genes involved in the protection of the two photosystems. This particular gene expression in the infected leaves was linked to the chlorosis and mosaic induced by the PLMVd. However, we cannot conclude with certitude if these symptoms are a cause or a consequence of this particular genes expression. The cDNA-AFLP has also allowed to identify the repression of genes coding for heat shock proteins (HSPs) in symptomatic leaves. These proteins generally have a role in the protein folding, assembly, translocation, stabilization and degradation. The regulation of their expression may have a great influence in the infected plants and, maybe, play a role in the symptoms expression. The gene coding for the novel cap-binding protein (nCBP) was also identified has repressed in the symptomatic leaves. The biological role of these proteins is unclear but it seems that these proteins act in the regulation of the mRNA translation. The repression of nCBP may thus have an important impact and to destabilize various biological pathways. Finally, two genes implicated in the plant defence were identified. One coding for a polygalacturonase inhibitor (over-expressed in symptomatic leaves) and the other one coding for a thiamine intermediate (involved in the SAR and over-expressed in the non-symptomatic leaves). The role of these proteins in the plant defence against the PLMVd is however unclear. To our knowledge, this is the first work where the host-pathogen relationship established during a PLMVd infection are studied. This is also the first time were the gene expression is linked to the viroid-induced symptoms. [less ▲]

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See detailMolecular characterization of tunisian variants of Peach Latent Mosaic viroid (PLMVD).
Fekih Hassen, I.; Massart, Sébastien ULg; Roussel, S. et al

Conference (2006)

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See detailMolecular characterization of varicella-zoster virus gene expression
Defechereux, Patricia; Baudoux, Laurence; Jackers, Pascale ULg et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

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See detailMolecular classification of T-cell lymphomas.
De Leval, Laurence ULg; Bisig, Bettina ULg; Thielen, Caroline ULg et al

in Critical Reviews in Oncology/Hematology (2009)

T-cell neoplasms encompass a heterogeneous group of relatively rare disease entities. This review, focused on lymphoblastic tumors (T-ALL/LBL) and nodal-based peripheral T-cell lymphomas (PTCL ... [more ▼]

T-cell neoplasms encompass a heterogeneous group of relatively rare disease entities. This review, focused on lymphoblastic tumors (T-ALL/LBL) and nodal-based peripheral T-cell lymphomas (PTCL), summarizes recent advances in the molecular characterization of these diseases. In T-ALL/LBL, molecular subgroups delineated by gene expression profiling correlate with leukemic arrest at specific stages of normal thymocyte development and different oncogenic pathways, and seem to be of interest for prognosis prediction. Angioimmunoblastic T-cell lymphoma (AITL), one of the most common PTCL entities, comprises neoplastic cells with a molecular signature similar to normal follicular helper T cells, and this cellular derivation might account for several of the peculiar aspects of this disease. Except in ALK-positive anaplastic large cell lymphoma, defined by ALK gene fusions, chromosomal translocations are otherwise rare in PTCLs, but some recurrent rearrangements might be associated with distinct lymphoma subtypes. In PTCL, not otherwise specified (PTCL, NOS), novel molecular biomarkers of potential therapeutic interest have been recently identified. [less ▲]

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See detailMolecular cloning and characterisation of the CD18 partner in ovine (Ovis aries) beta(2)-integrins
Zecchinon, Laurent ULg; Fett, Thomas ULg; Baise, Etienne ULg et al

in Gene (2004), 334

The leukocyte integrins play a critical role in a number of cellular adhesive interactions during the immune response. We describe here the isolation and characterization of the ovine beta(2) (CD18 ... [more ▼]

The leukocyte integrins play a critical role in a number of cellular adhesive interactions during the immune response. We describe here the isolation and characterization of the ovine beta(2) (CD18) subunit, common to the leukocyte beta(2)-integrin family. The deduced 770-amino-acid sequence reveals a transmembrane protein with 81%, 83% and 95% identity with its murine, human and bovine homologues, respectively. Comparisons of CD18 sequences emphasize the functional importance of the beta(2) subunit I-like domain and included metal ion-dependent adhesion site (MIDAS)-like motif and confirm that of the cytoplasmic tail. The data provided here will offer the possibility to explore new avenues in studies based on the ovine model. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailMolecular cloning and characterization of a soluble inorganic pyrophosphatase in potato.
du Jardin, Patrick ULg; Rojas-Beltran, J.; Gebhardt, C. et al

in Plant Physiology (1995), 109(3), 853-60

A cDNA clone encoding a soluble inorganic pyrophosphatase (EC 3.6.1.1) of potato (Solanum tuberosum L.) was isolated by screening a developing tuber library with a heterologous probe. The central domain ... [more ▼]

A cDNA clone encoding a soluble inorganic pyrophosphatase (EC 3.6.1.1) of potato (Solanum tuberosum L.) was isolated by screening a developing tuber library with a heterologous probe. The central domain of the encoded polypeptide is nearly identical at the sequence level with its Arabidopsis homolog (J.J. Kieber and E.R. Signer [1991] Plant Mol Biol 16: 345-348). Computer-assisted analysis of the potato, Arabidopsis, and Escherichia coli soluble pyrophosphatases indicated a remarkably conserved organization of the hydrophobic protein domains. The enzymatic function of the potato protein could be deduced from the presence of amino acid residues highly conserved in soluble pyrophosphatases and was confirmed by its capacity to complement a thermosensitive pyrophosphatase mutation in E. coli. The potato polypeptide was purified from complemented bacterial cells and its pyrophosphatase activity was shown to be strictly dependent on Mg2+ and strongly inhibited by Ca2+. The subcellular location of the potato pyrophosphatase is unknown. Structure analysis of the N-terminal protein domain failed to recognize typical transit peptides and the calculated molecular mass of the polypeptide (24 kD) is significantly inferior to the values reported for the plastidic (alkaline) or mitochondrial pyrophosphatases in plants (28-42 kD). Two unlinked loci could be mapped by restriction fragment length polymorphism analysis in the potato genome using the full-length cDNA as probe. [less ▲]

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See detailMolecular Cloning And Characterization Of The Enzyme Udp-Glucose: Protein Transglucosylase From Potato
Bocca, Sn.; Kissen, R.; Rojas-Beltran, Ja. et al

in Plant Physiology and Biochemistry (1999), 37(11),

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See detailMolecular cloning and characterization of two forms of trout growth hormone cDNA: expression and secretion of tGH-II by Escherichia coli
Rentier-Delrue, Françoise ULg; Swennen, D.; Mercier, L. et al

in DNA (1989), 8(2), 109-17

We constructed a cDNA library using mRNA isolated from rainbow trout pituitaries. Two types of cDNA clones encoding growth hormone (GH) were isolated and their complete nucleotide sequences determined ... [more ▼]

We constructed a cDNA library using mRNA isolated from rainbow trout pituitaries. Two types of cDNA clones encoding growth hormone (GH) were isolated and their complete nucleotide sequences determined. Twenty seven nucleotide substitutions in the coding region and 108 in the noncoding region distinguish the cDNAs of trout GH-I and II. Both cDNAs encode polypeptides of 210 amino acids, including a putative signal peptide of 22 amino acids, which differ by 12 residues. In both trout and salmon, GH-I mRNA is predominant, which suggests that the variation in the amount of secreted GH originates from a transcriptional event. Moreover, comparison of rainbow trout and chum salmon GH reveals that, in both cases, the predominant GH-I has mutated less than its GH-II counterpart. Mature tGH-II was expressed in Escherichia coli using the pIN-III-ompA-Hind secretion vector. [less ▲]

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See detailMolecular cloning and chromosomal mapping of olfactory receptor genes expressed in the male germ line: evidence for their wide distribution in the human genome
Vanderhaeghen, P.; Schurmans, Stéphane ULg; Vassart, G. et al

in Biochemical and Biophysical Research Communications (1997), 237

Olfactory receptor genes constitute the largest family of G protein-coupled receptors. We have previously shown that members of this family are expressed during spermatogenesis, and that the corresponding ... [more ▼]

Olfactory receptor genes constitute the largest family of G protein-coupled receptors. We have previously shown that members of this family are expressed during spermatogenesis, and that the corresponding proteins are displayed on mature sperm cells. In each mammalian species, a restricted subset of olfactory receptors is expressed in male germ cells and displays a pattern of expression suggestive of their potential implication in the control of sperm physiology. In addition to the cDNA fragments available previously, we now report the molecular cloning of two olfactory receptor cDNAs from a human testis library. Five olfactory receptor genes expressed in germ cells were localized in the human genome by radiation hybrid mapping. Three of the genes map to the short arm of chromosome 19 (19p13.1-19p31.3), one to chromosome 11 (11q22.1-22.3), and one to chromosome 17 (17q21-22). The former two localizations fall within clusters previously identified for members of the putative olfactory receptor gene family expressed in olfactory mucosa. Similarly, sequence analysis has revealed that these testicular genes share no distinctive structural features from the other, non-testicular, members of the family. The expression of a subset of olfactory receptor genes in the male germ line is therefore not correlated to their belonging to a specific structural subgroup, or to a specific gene cluster or chromosomal segment [less ▲]

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See detailMolecular cloning and functional expression of a new aphid isoprenyl diphosphate synthase
Vandermoten, Sophie ULg; Beliveau, Catherine; Sen, Stephanie et al

Poster (2006, December 18)

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