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71.
Proteome analysis of grape skins during ripening 总被引:3,自引:0,他引:3
Deytieux C Geny L Lapaillerie D Claverol S Bonneu M Donèche B 《Journal of experimental botany》2007,58(7):1851-1862
The characterization of proteins isolated from skin tissue is apparently an essential parameter for understanding grape ripening as this tissue contains the key compounds for wine quality. It has been particularly difficult to extract proteins from skins for analysis by two-dimensional electrophoresis gels and, therefore, a protocol for this purpose has been adapted. The focus was on the evolution of the proteome profile of grape skin during maturation. Proteome maps obtained at three stages of ripening were compared to assess the extent to which protein distribution differs in grape skin during ripening. The comparative analysis shows that numerous soluble skin proteins evolve during ripening and reveal specific distributions at different stages. Proteins involved in photosynthesis, carbohydrate metabolisms, and stress response are identified as being over-expressed at the beginning of colour-change. The end of colour-change is characterized by the over-expression of proteins involved in anthocyanin synthesis and, at harvest, the dominant proteins are involved in defence mechanisms. In particular, increases in the abundance of different chitinase and beta-1,3-glucanase isoforms were found as the berry ripens. This observation can be correlated with the increase of the activities of both of these enzymes during skin ripening. The differences observed in proteome maps clearly show that significant metabolic changes occur in grape skin during this crucial phase of ripening. This comparative analysis provides more detailed characterization of the fruit ripening process. 相似文献
72.
Matthew-Wood syndrome is caused by truncating mutations in the retinol-binding protein receptor gene STRA6 总被引:3,自引:0,他引:3 下载免费PDF全文
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75.
Casas J Magal C Sueur J 《Proceedings. Biological sciences / The Royal Society》2007,274(1613):1087-1092
Vibratory communication in arthropods is a widespread phenomenon. Arthropods living on plants have been reported to use only dispersive bending waves in the context of prey-predator, competition, social and sexual interactions. Differences in signal structure have also been postulated to work as species recognition mechanisms and speciation agents. Using two identical laser Doppler vibrometers and a wavelet analysis, we quantified the wave propagation modes in rush stems (Juncus effusus) over the whole range of frequencies used by arthropods. A non-dimensionalized analysis shows that mechanical waves propagate not only as dispersive bending waves, but also as non-dispersive waves. Our analysis implies that an arthropod can communicate through non-dispersive bending waves by either producing signals of high frequencies or by choosing large stems, two widely different options tapping into the physiological and the behavioural repertoires, respectively. Non-dispersive waves, unreported so far in insect vibratory communication in plants, present serious advantages over dispersive bending waves in terms of signal integrity and may well be much more widely used than anticipated, in particular for species recognition. 相似文献
76.
Matthieu Guillemain Romain Blanc Christelle Lucas Michel Lepley 《Biodiversity and Conservation》2007,16(12):3633-3651
Ecotourism is becoming very popular, especially in protected areas where wildlife concentrate and is easier to observe, but
the consequences of associated disturbance have seldom be quantified other than in the short-term, making the sustainability
of this activity untested. We combined a historical, an empirical and an experimental approach to assess the long-, medium-
and short-term consequences of disturbance to wintering wildfowl (Anatidae) in a wetland of international importance in the Camargue, Southern France. In the short-term, disturbance made teal (Anas crecca) move away temporarily from observation blinds without leaving the waterbody. Wildfowl fed more after disturbance, disrupting
their normal resting activities. In the medium-term, waterbodies with more tourists did not host fewer birds: conversely the
most heavily disturbed one hosted the highest wildfowl density. In the long term, wildfowl numbers were not related with the
number of visitors. When practiced with appropriate guiding of people, and where appropriate facilities are provided to limit
human disturbance as done here, ecotourism may not affect wintering wildfowl other than reversibly in the very short term.
The legitimate demand of the public for access, even in fragile protected areas, may therefore be sustainable under some conditions. 相似文献
77.
Rheological characteristics during chemical gelation with the cross-linker ethylene glycol diglycidyl ether (EGDE) of semidilute aqueous solutions of hydroxyethylcellulose (HEC) and of two hydrophobically modified analogues (HM-1-HEC and HM-2-HEC) are reported. In addition, rheological features of gelling samples (dextran and its hydrophobically modified analogue (HM-dextran)) of a different structure have been examined. Some swelling experiments on these gels in the postgel region are also reported. The gelation time of the hydroxyethylcellulose systems decreased with increasing cross-linker concentration, and incorporation of hydrophobic units of HEC resulted in a slower gelation. The time of gelation for the dextran system was only slightly affected by the incorporation of hydrophobic groups (HM-dextran). At the gel point, a power law frequency dependence of the dynamic storage modulus (G' proportional to omegan') and loss modulus (G' proportional to omegan') was observed for all gelling systems with n' = n' = n. The attachment of hydrophobic moieties on the dextran chains had virtually no impact on the value of n (n = 0.77), and the percolation model describes the incipient dextran gels. By increasing the number of hydrophobic groups of the HEC polymer, the value of n for the corresponding incipient gel drops significantly, and the value of the gel strength parameter increases strongly. Incorporation of hydrophobic units in the HEC chains promotes the formation of stronger incipient gels because of the contribution from the hydrophobic association effect. The frequency dependence of the complex viscosity reveals that all the investigated gels become more solidlike in the postgel domain. Far into the postgel region, the hydrophobicity of HEC plays a minor role for the strength of the gel network, whereas the values of the complex viscosity are significantly higher for HM-dextran than for the corresponding dextran gel. The swelling experiments on HEC, HM-1-HEC, and HM-2-HEC systems disclose that the degree of swelling of the postgels in water is quite different, depending on the relative distance from the gel point at which the cross-linker reaction is quenched. At a given distance from the gel point, the swelling of the HEC gel is less pronounced than for the corresponding hydrophobically modified samples. At this stage, the swelling of the HM-dextran gel is stronger than for the dextran gel. 相似文献
78.
Evidence for ACD5 ceramide kinase activity involvement in Arabidopsis response to cold stress 下载免费PDF全文
Christelle Dutilleul Heidy Chavarria Nathalie Rézé Bruno Sotta Emmanuel Baudouin Isabelle Guillas 《Plant, cell & environment》2015,38(12):2688-2697
Although sphingolipids emerged as important signals for plant response to low temperature, investigations have been limited so far to the function of long‐chain base intermediates. The formation and function of ceramide phosphates (Cer‐Ps) in chilled Arabidopsis were explored. Cer‐Ps were analysed by thin layer chromatography (TLC) following in vivo metabolic radiolabelling. Ceramide kinase activity, gene expression and growth phenotype were determined in unstressed and cold‐stressed wild type (WT) and Arabidopsis ceramide kinase mutant acd5. A rapid and transient formation of Cer‐P occurs in cold‐stressed WT Arabidopsis plantlets and cultured cells, which is strongly impaired in acd5 mutant. Although concomitant, Cer‐P formation is independent of long‐chain base phosphate (LCB‐P) formation. No variation of ceramide kinase activity was measured in vitro in WT plantlets upon cold stress but the activity in acd5 mutant was further reduced by cold stress. At the seedling stage, acd5 response to cold was similar to that of WT. Nevertheless, acd5 seed germination was hypersensitive to cold and abscisic acid (ABA), and ABA‐dependent gene expression was modified in acd5 seeds when germinated at low temperature. Our data involve for the first time Cer‐P and ACD5 in low temperature response and further underline the complexity of sphingolipid signalling operating during cold stress. 相似文献
79.
Christelle Borel Pedro?G. Ferreira Federico Santoni Olivier Delaneau Alexandre Fort Konstantin?Y. Popadin Marco Garieri Emilie Falconnet Pascale Ribaux Michel Guipponi Ismael Padioleau Piero Carninci Emmanouil?T. Dermitzakis Stylianos?E. Antonarakis 《American journal of human genetics》2015,96(1):70-80
80.
Mineem Saliba Nick Ramalanjaona Sandrine Gulberti Isabelle Bertin-Jung Aline Thomas Samir Dahbi Chrystel Lopin-Bon Jean-Claude Jacquinet Christelle Breton Mohamed Ouzzine Sylvie Fournel-Gigleux 《The Journal of biological chemistry》2015,290(12):7658-7670
Among glycosaminoglycan (GAG) biosynthetic enzymes, the human β1,4-galactosyltransferase 7 (hβ4GalT7) is characterized by its unique capacity to take over xyloside derivatives linked to a hydrophobic aglycone as substrates and/or inhibitors. This glycosyltransferase is thus a prime target for the development of regulators of GAG synthesis in therapeutics. Here, we report the structure-guided design of hβ4GalT7 inhibitors. By combining molecular modeling, in vitro mutagenesis, and kinetic measurements, and in cellulo analysis of GAG anabolism and decorin glycosylation, we mapped the organization of the acceptor binding pocket, in complex with 4-methylumbelliferone-xylopyranoside as prototype substrate. We show that its organization is governed, on one side, by three tyrosine residues, Tyr194, Tyr196, and Tyr199, which create a hydrophobic environment and provide stacking interactions with both xylopyranoside and aglycone rings. On the opposite side, a hydrogen-bond network is established between the charged amino acids Asp228, Asp229, and Arg226, and the hydroxyl groups of xylose. We identified two key structural features, i.e. the strategic position of Tyr194 forming stacking interactions with the aglycone, and the hydrogen bond between the His195 nitrogen backbone and the carbonyl group of the coumarinyl molecule to develop a tight binder of hβ4GalT7. This led to the synthesis of 4-deoxy-4-fluoroxylose linked to 4-methylumbelliferone that inhibited hβ4GalT7 activity in vitro with a Ki 10 times lower than the Km value and efficiently impaired GAG synthesis in a cell assay. This study provides a valuable probe for the investigation of GAG biology and opens avenues toward the development of bioactive compounds to correct GAG synthesis disorders implicated in different types of malignancies. 相似文献