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151.
Gekas J Hindié M Faucheux N Lanvin O Mazière C Fuentès V Gouilleux-Gruart V David B Mazière JC Lassoued K Nagel MD 《FEBS letters》2004,563(1-3):103-107
Cell shape was found to be a strong indicator of whether individual cells grow or die, and may play an important role in controlling apoptosis as well as cell growth. We compared here the behaviour of rounded Swiss 3T3 cells aggregated on a cellulose cuprophan membrane to those cultured on dish polystyrene. We demonstrated that cells aggregated on cellulose substrates for up to 48 h underwent programmed cell death that was associated with phosphatidylserine flipping and caspase 9 and caspase 3 activation, suggesting a mitochondria-dependent apoptotic process. In addition, we found that this phenomenon cannot be entirely explained by disengagement of alpha 5 beta 1 integrin ligation. 相似文献
152.
Demanèche S Meyer C Micoud J Louwagie M Willison JC Jouanneau Y 《Applied and environmental microbiology》2004,70(11):6714-6725
In this study, the enzymes involved in polycyclic aromatic hydrocarbon (PAH) degradation in the chrysene-degrading organism Sphingomonas sp. strain CHY-1 were investigated. [14C]chrysene mineralization experiments showed that PAH-grown bacteria produced high levels of chrysene-catabolic activity. One PAH-induced protein displayed similarity with a ring-hydroxylating dioxygenase beta subunit, and a second PAH-induced protein displayed similarity with an extradiol dioxygenase. The genes encoding these proteins were cloned, and sequence analysis revealed two distinct loci containing clustered catabolic genes with strong similarities to corresponding genes found in Novosphingobium aromaticivorans F199. In the first locus, two genes potentially encoding a terminal dioxygenase component, designated PhnI, were followed by a gene coding for an aryl alcohol dehydrogenase (phnB). The second locus contained five genes encoding an extradiol dioxygenase (phnC), a ferredoxin (phnA3), another oxygenase component (PhnII), and an isomerase (phnD). PhnI was found to be capable of converting several PAHs, including chrysene, to the corresponding dihydrodiols. The activity of PhnI was greatly enhanced upon coexpression of genes encoding a ferredoxin (phnA3) and a reductase (phnA4). Disruption of the phnA1a gene encoding the PhnI alpha subunit resulted in a mutant strain that had lost the ability to grow on PAHs. The recombinant PhnII enzyme overproduced in Escherichia coli functioned as a salicylate 1-hydroxylase. PhnII also used methylsalicylates and anthranilate as substrates. Our results indicated that a single enzyme (PhnI) was responsible for the initial attack of a range of PAHs, including chrysene, in strain CHY-1. Furthermore, the conversion of salicylate to catechol was catalyzed by a three-component oxygenase unrelated to known salicylate hydroxylases. 相似文献
153.
Lemercier C Legube G Caron C Louwagie M Garin J Trouche D Khochbin S 《The Journal of biological chemistry》2003,278(7):4713-4718
Here we show that the phosphorylation of histone acetyltransferase Tip60, a target of human immunodeficiency virus, type 1-encoded transactivator Tat, plays a crucial role in the control of its catalytic activity. Baculovirus-based expression and purification of Tip60 combined with mass spectrometry allowed the identification of serines 86 and 90 as two major sites of phosphorylation in vivo. The phosphorylation of Tip60 was found to modulate its histone acetyltransferase activity. One of the identified phosphorylated serines, Ser-90, was within a consensus cyclin B/Cdc2 site. Ser-90 was specifically phosphorylated in vitro by the cyclin B/Cdc2 complex. Accordingly, the phosphorylation of Tip60 was enhanced after drug-induced arrest of cells in G(2)/M. This G(2)/M-dependent phosphorylation of Tip60 was abolished by treating cells with a specific inhibitor of the cyclin-dependent kinase, roscovitin. All together, these results strongly suggest a G(2)/M-dependent control of Tip60 activity. 相似文献
154.
Irena Bo
kaj Tosca E. I. Martini Eduardo S. de Camargo Magalhes Petra L. Bakker Tiny G. J. Meeuwsen-de Boer Inna Armandari Saskia L. Meuleman Marin T. Mondria Colin Stok Yannick P. Kok Bjorn Bakker Ren Wardenaar Jonas Seiler Mathilde J. C. Broekhuis Hilda van den Bos Diana C. J. Spierings Femke C. A. Ringnalda Hans Clevers Ulrich Schüller Marcel A. T. M. van Vugt Floris Foijer Sophia W. M. Bruggeman 《PLoS genetics》2021,17(11)
While comprehensive molecular profiling of histone H3.3 mutant pediatric high-grade glioma has revealed extensive dysregulation of the chromatin landscape, the exact mechanisms driving tumor formation remain poorly understood. Since H3.3 mutant gliomas also exhibit high levels of copy number alterations, we set out to address if the H3.3K27M oncohistone leads to destabilization of the genome. Hereto, we established a cell culture model allowing inducible H3.3K27M expression and observed an increase in mitotic abnormalities. We also found enhanced interaction of DNA replication factors with H3.3K27M during mitosis, indicating replication defects. Further functional analyses revealed increased genomic instability upon replication stress, as represented by mitotic bulky and ultrafine DNA bridges. This co-occurred with suboptimal 53BP1 nuclear body formation after mitosis in vitro, and in human glioma. Finally, we observed a decrease in ultrafine DNA bridges following deletion of the K27M mutant H3F3A allele in primary high-grade glioma cells. Together, our data uncover a role for H3.3 in DNA replication under stress conditions that is altered by the K27M mutation, promoting genomic instability and potentially glioma development. 相似文献
155.
Michel Ntetani Aloni René Makwala Ngiyulu Jean-Lambert Gini-Ehungu Célestin Ndosimao Nsibu Mathilde Bothale Ekila Fran?ois Bompeka Lepira Nazaire Mangani Nseka 《PloS one》2014,9(5)
Background
The prevalence of Sickle cell disease is extremely high in Democratic Republic of Congo. Despite this high prevalence of the disease, data on renal abnormalities in children are rare.Method
The study proposed to assess blood pressure, glomerular function, urea and uric acid levels in 65 steady state Congolese children with homozygous sickle cell disease and 67 normal controls.Results
In Hb-SS group, blood pressure level tended to be lower than Hb-AA groups but there was no statistically significant difference (p>0.05) between the two groups. The absolute values for GFR corrected for BSA were significantly higher in Hb-SS group compared to Hb-AA group (130.5±34.1 ml/min/1.73 m2 vs 113.7±24.5 ml/min/1.73 m2; p = 0.004). Children with Hb-SS were more likely to hyperfiltrate (30.8% of subjects) than children with Hb-AA (6.1% of subjects). Proteinuria was found in 4 (6.2%) children with Hb-SS. Uric acid level was significantly increased in children with Hb-SS compared to corresponding values in control group (4.4±1.3 mg/dl vs 3.5±1.1 mg/dl; p<0.001). Urea level was significantly decreased compared to corresponding values in Hb-AA group (15.3±8.3 mg/dl vs 22.9±10.1 mg/dl; p<0.001).Conclusion
Hyperfiltration, low creatinine, lower urea and high uric acid are more common in children with sickle cell disease than in normal controls. 相似文献156.
Inge Geurden Peter Borchert Mukundh N. Balasubramanian Johan W. Schrama Mathilde Dupont-Nivet Edwige Quillet Sadasivam J. Kaushik Stéphane Panserat Fran?oise Médale 《PloS one》2013,8(12)
Sustainable aquaculture, which entails proportional replacement of fish-based feed sources by plant-based ingredients, is impeded by the poor growth response frequently seen in fish fed high levels of plant ingredients. This study explores the potential to improve, by means of early nutritional exposure, the growth of fish fed plant-based feed. Rainbow trout swim-up fry were fed for 3 weeks either a plant-based diet (diet V, V-fish) or a diet containing fishmeal and fish oil as protein and fat source (diet M, M-fish). After this 3-wk nutritional history period, all V- or M-fish received diet M for a 7-month intermediate growth phase. Both groups were then challenged by feeding diet V for 25 days during which voluntary feed intake, growth, and nutrient utilisation were monitored (V-challenge). Three isogenic rainbow trout lines were used for evaluating possible family effects. The results of the V-challenge showed a 42% higher growth rate (P = 0.002) and 30% higher feed intake (P = 0.005) in fish of nutritional history V compared to M (averaged over the three families). Besides the effects on feed intake, V-fish utilized diet V more efficiently than M-fish, as reflected by the on average 18% higher feed efficiency (P = 0.003). We noted a significant family effect for the above parameters (P<0.001), but the nutritional history effect was consistent for all three families (no interaction effect, P>0.05). In summary, our study shows that an early short-term exposure of rainbow trout fry to a plant-based diet improves acceptance and utilization of the same diet when given at later life stages. This positive response is encouraging as a potential strategy to improve the use of plant-based feed in fish, of interest in the field of fish farming and animal nutrition in general. Future work needs to determine the persistency of this positive early feeding effect and the underlying mechanisms. 相似文献
157.
158.
Anna K. Hundsdoerfer Michael B. Mende Ian J. Kitching Mathilde Cordellier 《Zoologica scripta》2011,40(4):403-417
Hundsdoerfer, AK., Mende, MB., Kitching, IJ. & Cordellier, M. (2011). Taxonomy, phylogeography and climate relations of the Western Palaearctic spurge hawkmoth (Lepidoptera, Sphingidae, Macroglossinae). —Zoologica Scripta, 40, 403–417. The primary aim of this study was to analyse mitochondrial genetic variability within the Hyles euphorbiae lineage in the Western Palaearctic, where observations of morphology have indicated much greater differentiation than is implied by the current taxonomy. The scope of the study is broadened further by including an analysis of the possible influences of climatic factors on lineage distributions. Mitochondrial sequences from three genes totalling an unambiguous alignment of 2284 bp were obtained for 356 individuals of the H. euphorbiae complex (HEC) s.s. Genetic admixture, network and climatic factor analyses were used to analyse the data. Unexpected mitochondrial variability was uncovered within the distribution range of H. euphorbiae in southern Europe, with two additional distinct clusters being found, both with rather patchy occurrences. The results of the genetic analysis presented here confirm a distinct H. cretica on Crete and the Dodecanese Islands and a distinct H. robertsi in Iran that hybridises with H. euphorbiae. Comparison of the molecular data with larval morphology shows only limited correlation of genetic clusters with pattern elements. The genetic network of the HEC s.s. shows strong incongruence with traditional taxonomy. Ecological niche modelling based on climate data revealed that the three best‐sampled clusters (H. tithymali, the well‐known H. euphorbiae lineage from Europe, and the previously unknown mitochondrial H. euphorbiae lineage that occurs mainly in Italy) could all occur in southern Italy and on the Mediterranean Islands. Biotic interactions appear to explain the observed ranges better than abiotic factors alone. 相似文献
159.
A reassessment of the presumed Badegoulian skull from Rond‐du‐Barry cave (Polignac,France), using direct AMS radiocarbon dating 下载免费PDF全文
160.
Christophe Sallaud Denis Rontein Sandrine Onillon Fran?oise Jabès Philippe Duffé Cécile Giacalone Samuel Thoraval Camille Escoffier Ga?tan Herbette Nathalie Leonhardt Mathilde Causse Alain Tissier 《The Plant cell》2009,21(1):301-317
In the wild tomato Solanum habrochaites, the Sst2 locus on chromosome 8 is responsible for the biosynthesis of several class II sesquiterpene olefins by glandular trichomes. Analysis of a trichome-specific EST collection from S. habrochaites revealed two candidate genes for the synthesis of Sst2-associated sesquiterpenes. zFPS encodes a protein with homology to Z-isoprenyl pyrophosphate synthases and SBS (for Santalene and Bergamotene Synthase) encodes a terpene synthase with homology to kaurene synthases. Both genes were found to cosegregate with the Sst2 locus. Recombinant zFPS protein catalyzed the synthesis of Z,Z-FPP from isopentenylpyrophosphate (IPP) and dimethylallylpyrophosphate (DMAPP), while coincubation of zFPS and SBS with the same substrates yielded a mixture of olefins identical to the Sst2-associated sesquiterpenes, including (+)-α-santalene, (+)-endo-β-bergamotene, and (−)-endo-α-bergamotene. In addition, headspace analysis of tobacco (Nicotiana sylvestris) plants expressing zFPS and SBS in glandular trichomes afforded the same mix of sesquiterpenes. Each of these proteins contains a putative plastid targeting sequence that mediates transport of a fused green fluorescent protein to the chloroplasts, suggesting that the biosynthesis of these sesquiterpenes uses IPP and DMAPP from the plastidic DXP pathway. These results provide novel insights into sesquiterpene biosynthesis and have general implications concerning sesquiterpene engineering in plants. 相似文献