排序方式: 共有25条查询结果,搜索用时 15 毫秒
11.
12.
Zhang H Shinmyo Y Hirose A Mito T Inoue Y Ohuchi H Loukeris TG Eggleston P Noji S 《Development, growth & differentiation》2002,44(5):409-417
Effective germline transformation of insects has been shown to depend on the right choice of transposon system and selection marker. In this study the promoter region of a Gryllus cytoplasmic actin (GbA3/4) gene was isolated and characterized, and was used to drive the expression of Minos transposase in embryos of the cricket Gryllus bimaculatus. Active Minos transposase was produced in these embryos as monitored through established transposon excision and interplasmid transposition assays. In contrast, Drosophila melanogaster hsp70 promoter, previously used to express Minos transposase in a number of insect species and insect cell lines, failed to produce any detectable Minos transposase activity, as recorded by using the very sensitive transposon excision assay. In addition, the GbA3/4 promoter was found to drive expression of enhanced green fluorescent protein (eGFP) predominantly in vitellophages of the developing Gryllus eggs when a plasmid carrying a GbA3/4 promoter-eGFP fusion gene was transiently injected into embryos. These results strongly support the use of Minos transposons marked with the GbA3/4 promoter-eGFP for the genetic transformation of this emerging model insect species. 相似文献
13.
FR258900, a potential anti-hyperglycemic drug, binds at the allosteric site of glycogen phosphorylase 总被引:1,自引:0,他引:1
Tiraidis C Alexacou KM Zographos SE Leonidas DD Gimisis T Oikonomakos NG 《Protein science : a publication of the Protein Society》2007,16(8):1773-1782
FR258900 has been discovered as a novel inhibitor of human liver glycogen phosphorylase a and proved to suppress hepatic glycogen breakdown and reduce plasma glucose concentrations in diabetic mice models. To elucidate the mechanism of inhibition, we have determined the crystal structure of the cocrystallized rabbit muscle glycogen phosphorylase b-FR258900 complex and refined it to 2.2 A resolution. The structure demonstrates that the inhibitor binds at the allosteric activator site, where the physiological activator AMP binds. The contacts from FR258900 to glycogen phosphorylase are dominated by nonpolar van der Waals interactions with Gln71, Gln72, Phe196, and Val45' (from the symmetry-related subunit), and also by ionic interactions from the carboxylate groups to the three arginine residues (Arg242, Arg309, and Arg310) that form the allosteric phosphate-recognition subsite. The binding of FR258900 to the protein promotes conformational changes that stabilize an inactive T-state quaternary conformation of the enzyme. The ligand-binding mode is different from those of the potent phenoxy-phthalate and acyl urea inhibitors, previously described, illustrating the broad specificity of the allosteric site. 相似文献
14.
15.
16.
Patrick Kemmeren Katrin Sameith Loes A.L. van de Pasch Joris J. Benschop Tineke L. Lenstra Thanasis Margaritis Eoghan O’Duibhir Eva Apweiler Sake van Wageningen Cheuk W. Ko Sebastiaan van Heesch Mehdi M. Kashani Giannis Ampatziadis-Michailidis Mariel O. Brok Nathalie A.C.H. Brabers Anthony J. Miles Diane Bouwmeester Sander R. van Hooff Harm van Bakel Erik Sluiters Linda V. Bakker Berend Snel Philip Lijnzaad Dik van Leenen Marian J.A. Groot Koerkamp Frank C.P. Holstege 《Cell》2014
17.
Ioannis Spilanis Thanasis Kizos Maria Koulouri Julia Kondyli Hristos Vakoufaris Ioannis Gatsis 《Ecological Indicators》2009,9(1):179-187
The notion of sustainability is used widely at the policy level, but only few approaches deal with its measurement, especially at the local level. Here, we develop and apply a practical tool for the estimation of the sustainability state at the island level with the use of indicators selected and adapted from international agencies and institutes, in a framework which is an expanded version of the DPSR approach. The identification of the significant sustainability state factors and the selection of the indicators are based on areas’ characteristics, namely their insularity and the fact that they are in the Mediterranean. The values of these indicators were obtained or calculated for the islands of Paros and Kos in Greece. The findings reveal that the method can be of great use for the sustainability evaluation and for planning the sustainable development of islands. 相似文献
18.
Zoi Tampaki Ramadhan S. Mwakubambanya Evi Goulielmaki Sofia Kaforou Kami Kim Andrew P. Waters Vern B. Carruthers Inga Siden-Kiamos Thanasis G. Loukeris Konstantinos Koussis 《PloS one》2015,10(3)
Regulated proteolysis is known to control a variety of vital processes in apicomplexan parasites including invasion and egress of host cells. Serine proteases have been proposed as targets for drug development based upon inhibitor studies that show parasite attenuation and transmission blockage. Genetic studies suggest that serine proteases, such as subtilisin and rhomboid proteases, are essential but functional studies have proved challenging as active proteases are difficult to express. Proteinaceous Protease Inhibitors (PPIs) provide an alternative way to address the role of serine proteases in apicomplexan biology. To validate such an approach, a Neospora caninum Kazal inhibitor (NcPI-S) was expressed ectopically in two apicomplexan species, Toxoplasma gondii tachyzoites and Plasmodium berghei ookinetes, with the aim to disrupt proteolytic processes taking place within the secretory pathway. NcPI-S negatively affected proliferation of Toxoplasma tachyzoites, while it had no effect on invasion and egress. Expression of the inhibitor in P. berghei zygotes blocked their development into mature and invasive ookinetes. Moreover, ultra-structural studies indicated that expression of NcPI-S interfered with normal formation of micronemes, which was also confirmed by the lack of expression of the micronemal protein SOAP in these parasites. Our results suggest that NcPI-S could be a useful tool to investigate the function of proteases in processes fundamental for parasite survival, contributing to the effort to identify targets for parasite attenuation and transmission blockage. 相似文献
19.
20.
van Wageningen S Kemmeren P Lijnzaad P Margaritis T Benschop JJ de Castro IJ van Leenen D Groot Koerkamp MJ Ko CW Miles AJ Brabers N Brok MO Lenstra TL Fiedler D Fokkens L Aldecoa R Apweiler E Taliadouros V Sameith K van de Pasch LA van Hooff SR Bakker LV Krogan NJ Snel B Holstege FC 《Cell》2010,143(6):991-1004
To understand relationships between phosphorylation-based signaling pathways, we analyzed 150 deletion mutants of protein kinases and phosphatases in S. cerevisiae using DNA microarrays. Downstream changes in gene expression were treated as a phenotypic readout. Double mutants with synthetic genetic interactions were included to investigate genetic buffering relationships such as redundancy. Three types of genetic buffering relationships are identified: mixed epistasis, complete redundancy, and quantitative redundancy. In mixed epistasis, the most common buffering relationship, different gene sets respond in different epistatic ways. Mixed epistasis arises from pairs of regulators that have only partial overlap in function and that are coupled by additional regulatory links such as repression of one by the other. Such regulatory modules confer the ability to control different combinations of processes depending on condition or context. These properties likely contribute to the evolutionary maintenance of paralogs and indicate a way in which signaling pathways connect for multiprocess control. 相似文献