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81.
Bastien Hermant Agnès Desroches-Castan Marie-Hélène Prandini Philippe Huber Daniel Vittet 《BMC biotechnology》2007,7(1):20
Background
Angiogenesis assays are important tools for the identification of regulatory molecules and the potential development of therapeutic strategies to modulate neovascularization. Although numerous in vitro angiogenesis models have been developed in the past, they exhibit limitations since they do not recapitulate the entire angiogenic process or correspond to multi-step procedures that are not easy to use. Convenient, reliable, easily quantifiable and physiologically relevant assays are still needed for pharmacological screenings of angiogenesis. 相似文献82.
Yvon Sterkers Laurence Lachaud Nathalie Bourgeois Lucien Crobu Patrick Bastien Michel Pagès 《Molecular microbiology》2012,86(1):15-23
Leishmania are unicellular eukaryotes that have many markedly original molecular features compared with other uni‐ or multicellular eukaryotes like yeasts or mammals. Genome plasticity in this parasite has been the subject of many publications, and has been associated with drug resistance or adaptability. Aneuploidy has been suspected by several authors and it is now confirmed using state‐of‐the‐art technologies such as high‐throughput DNA sequencing. The analysis of genome contents at the single cell level using fluorescence in situ hybridization (FISH) has brought a new light on the genome organization: within a cell population, every chromosome, in every cell, may be present in at least two ploidy states (being either monosomic, disomic or trisomic), and the chromosomal content varies greatly from cell to cell, thus generating a constitutive intra‐strain genomic heterogeneity, here termed ‘mosaic aneuploidy’. Mosaic aneuploidy deeply affects the genetics of these organisms, leading, for example, to an extreme degree of intra‐strain genomic diversity, as well as to a clearance of heterozygous cells in the population without however affecting genetic heterogeneity. Second, mosaic aneuploidy might be considered as a powerful strategy evolved by the parasite for adapting to modifications of environment conditions as well as for the emergence of drug resistance. On the whole, mosaic aneuploidy may be considered as a novel mechanism for generating phenotypic diversity driven by genomic plasticity. 相似文献
83.
Sophie Y. Dillen Véronique Storme Nicolas Marron Catherine Bastien Sabrina Neyrinck Marijke Steenackers Reinhart Ceulemans Wout Boerjan 《Tree Genetics & Genomes》2009,5(1):147-164
Interspecific hybrids of Populus species are known for their superior growth. In this study, we examined the effect of the genetic background and contrasting
environmental conditions on growth and searched for quantitative trait loci (QTL) affecting growth traits. To this end, two
hybrid poplar families resulting from controlled crosses, Populus deltoides ‘S9-2’ × P. nigra ‘Ghoy’ (D × N, 180 F1) and P. deltoides ‘S9-2’ × P. trichocarpa ‘V24’ (D × T, 182 F1), were grown at two contrasting sites, Northern Italy and Central France. At the end of the second growing season, tree dimensions
(stem height, circumference, and volume) were assessed. The performances of both families significantly differed within and
between sites. Tree volume was significantly larger at the Italian site as compared to the French site. Genotype by environment
interactions were significant but low for both families and for all growth traits. Tight correlations among the individual
growth traits indicated that there may be a common genetic mechanism with pleiotropic effects on these growth traits. In line
with previous studies, linkage groups I, VII, IX, X, XVI, XVII, and XIX appeared to have genomic regions with the largest
effects on growth traits. This study revealed that (1) both families have high potential for selection of superior poplar
hybrids due to the pronounced heterosis (hybrid vigor) and the large genetic variability in terms of growth and (2) the choice
of site is crucial for poplar cultivation.
Dillen and Storme contributed equally to the work.
An erratum to this article can be found at 相似文献
84.
Dominic Bastien Valérie Leblanc Éric Asselin Gervais Bérubé 《Bioorganic & medicinal chemistry letters》2010,20(7):2078-2081
The synthesis of two separable isomeric testosterone dimers is reported. The dimers are made from testosterone in a 5 step sequence and with 36% overall yield. The key dimerization step was performed using Hoveyda–Grubb’s metathesis catalysts on 7α-allyltestosterone with 75% yield. The synthesis led to separable isomeric dimers (trans and cis, 2:1). X-ray diffraction crystallography, performed on monocrystal of the minor isomer, confirms the cis geometry of the double bound between the two testosterone units. MTT assays showed that the cis dimer has the highest activity against prostate cancer cell lines. The novel cis dimer is more active than the antiandrogen cyproterone acetate indicating the possible therapeutic value of this molecule. 相似文献
85.
86.
Emmanuelle Dubots Magali Audry Yoshiki Yamaryo Olivier Bastien Hiroyuki Ohta Christelle Breton Eric Mar��chal Maryse A. Block 《The Journal of biological chemistry》2010,285(9):6003-6011
One of the major characteristics of chloroplast membranes is their enrichment in galactoglycerolipids, monogalactosyldiacylglycerol (MGDG), and digalactosyldiacylglycerol (DGDG), whereas phospholipids are poorly represented, mainly as phosphatidylglycerol (PG). All these lipids are synthesized in the chloroplast envelope, but galactolipid synthesis is also partially dependent on phospholipid synthesis localized in non-plastidial membranes. MGDG synthesis was previously shown essential for chloroplast development. In this report, we analyze the regulation of MGDG synthesis by phosphatidic acid (PA), which is a general precursor in the synthesis of all glycerolipids and is also a signaling molecule in plants. We demonstrate that under physiological conditions, MGDG synthesis is not active when the MGDG synthase enzyme is supplied with its substrates only, i.e. diacylglycerol and UDP-gal. In contrast, PA activates the enzyme when supplied. This is shown in leaf homogenates, in the chloroplast envelope, as well as on the recombinant MGDG synthase, MGD1. PG can also activate the enzyme, but comparison of PA and PG effects on MGD1 activity indicates that PA and PG proceed through different mechanisms, which are further differentiated by enzymatic analysis of point-mutated recombinant MGD1s. Activation of MGD1 by PA and PG is proposed as an important mechanism coupling phospholipid and galactolipid syntheses in plants. 相似文献
87.
Job B Bernheim A Beau-Faller M Camilleri-Broët S Girard P Hofman P Mazières J Toujani S Lacroix L Laffaire J Dessen P Fouret P;LG Investigators 《PloS one》2010,5(12):e15145
Background
Lung cancer in never smokers would rank as the seventh most common cause of cancer death worldwide.Methods and Findings
We performed high-resolution array comparative genomic hybridization analysis of lung adenocarcinoma in sixty never smokers and identified fourteen new minimal common regions (MCR) of gain or loss, of which five contained a single gene (MOCS2, NSUN3, KHDRBS2, SNTG1 and ST18). One larger MCR of gain contained NSD1. One focal amplification and nine gains contained FUS. NSD1 and FUS are oncogenes hitherto not known to be associated with lung cancer. FISH showed that the amplicon containing FUS was joined to the next telomeric amplicon at 16p11.2. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. Other cancer genes present in aberrations included ARNT, BCL9, CDK4, CDKN2B, EGFR, ERBB2, MDM2, MDM4, MET, MYC and KRAS. Unsupervised hierarchical clustering with adjustment for false-discovery rate revealed clusters differing by the level and pattern of aberrations and displaying particular tumor characteristics. One cluster was strongly associated with gain of MYC. Another cluster was characterized by extensive losses containing tumor suppressor genes of which RB1 and WRN. Tumors in that cluster frequently harbored a central scar-like fibrosis. A third cluster was associated with gains on 7p and 7q, containing ETV1 and BRAF, and displayed the highest rate of EGFR mutations. SNP array analysis validated copy-number aberrations and revealed that RB1 and WRN were altered by recurrent copy-neutral loss of heterozygosity.Conclusions
The present study has uncovered new aberrations containing cancer genes. The oncogene FUS is a candidate gene in the 16p region that is frequently gained in never smokers. Multiple genetic pathways defined by gains of MYC, deletions of RB1 and WRN or gains on 7p and 7q are involved in lung adenocarcinoma in never smokers. 相似文献88.
Lawson TG Gronros DL Evans PE Bastien MC Michalewich KM Clark JK Edmonds JH Graber KH Werner JA Lurvey BA Cate JM 《The Journal of biological chemistry》1999,274(14):9871-9880
The amino acid sequence LLVRGRTLVV, which is probably located in a strand-turn-strand structure, has been identified as a protein destruction signal in the rapidly degraded encephalomyocarditis virus 3C protease. Mutations within this sequence reduced the susceptibility of the 3C protease toward ubiquitination and degradation in rabbit reticulocyte lysate. This signal is transferable, since poliovirus 3C protease, which is a poor ubiquitin-mediated proteolytic system substrate, was found to be ubiquitinated and degraded when the signal sequence was either generated at an internal location in the protein or fused to the N terminus. An evaluation of the behavior of 3C protease proteins containing mutations in the signal region indicates that considerable variability in the primary structure is tolerated, although the conservation of certain features appears to be required for signal function. Two E3 ubiquitin-protein ligases that recognize the encephalomyocarditis virus 3C protease as a substrate were also partially purified. One of these was identified as the previously described E3alpha, and this was shown to require the destruction signal sequence to catalyze efficiently the ubiquitination of the 3C protease. The other is a Ubc5-dependent E3 that appears to recognize a different, unidentified feature of the 3C protease. 相似文献
89.
A single amino acid determinant governs the species-specific sensitivity of APOBEC3G to Vif action 总被引:18,自引:0,他引:18
APOBEC3G (also known as CEM15) is an innate intracellular antiretroviral factor that is counteracted by the Vif protein of lentiviruses. While APOBEC3G orthologues from several species are active against a broad range of retroviruses, given Vif proteins have a narrow spectrum of activity. For instance, HIV-1 Vif efficiently blocks APOBEC3G from human but not African green monkey (AGM), whereas the reverse is observed with SIV(AGM) Vif. Here, we demonstrate that a single amino acid at position 128 of human and AGM APOBEC3G governs the virus-specific sensitivity of these proteins to Vif-mediated inhibition. Furthermore, we show that this phenotype correlates with the ability of Vif to bind APOBEC3G and interfere with its incorporation into virions. These results shed light on an important determinant of the tropism of primate lentiviruses. 相似文献
90.
Hermant B Bibert S Concord E Dublet B Weidenhaupt M Vernet T Gulino-Debrac D 《The Journal of biological chemistry》2003,278(16):14002-14012
Transmigration of neutrophils across the endothelium occurs at the cell-cell junctions where the vascular endothelium cadherin (VE cadherin) is expressed. This adhesive receptor was previously demonstrated to be involved in the maintenance of endothelium integrity. We propose that neutrophil transmigration across the vascular endothelium goes in parallel with cleavage of VE cadherin by elastase and cathepsin G present on the surface of neutrophils. This hypothesis is supported by the following lines of evidence. 1) Proteolytic fragments of VE cadherin are released into the culture medium upon adhesion of neutrophils to endothelial cell monolayers; 2) conditioned culture medium, obtained after neutrophil adhesion to endothelial monolayers, cleaves the recombinantly expressed VE cadherin extracellular domain; 3) these cleavages are inhibited by inhibitors of elastase; 4) VE cadherin fragments produced by conditioned culture medium or by exogenously added elastase are identical as shown by N-terminal sequencing and mass spectrometry analysis; 5) both elastase- and cathepsin G-specific VE cadherin cleavage patterns are produced upon incubation with tumor necrosis factor alpha-stimulated and fixed neutrophils; 6) transendothelial permeability increases in vitro upon addition of either elastase or cathepsin G; and 7) neutrophil transmigration is reduced in vitro in the presence of elastase and cathepsin G inhibitors. Our results suggest that cleavage of VE cadherin by neutrophil surface-bound proteases induces formation of gaps through which neutrophils transmigrate. 相似文献