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71.
Cleavage of colicin Ia by the Escherichia coli K-12 outer membrane is not mediated by the colicin Ia receptor. 总被引:9,自引:8,他引:1 下载免费PDF全文
Colicin Ia can be cleaved by isolated outer membranes prepared from sensitive and resistant (lacking the colicin Ia receptor) strains of Escherichia coli. Both active and heat-denatured colicin Ia are extensively fragmented. Such proteolysis does not occur when colicin Ia is added to whole sensitive or resistant cells. These results demonstrate that cleavage of colicin Ia is not mediated by its outer membrane receptor. 相似文献
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Restriction fragment length polymorphism (RFLP) analysis, previously shown to be a relatively simple and reproducible method for distinguishing discrete strains of E. granulosus, could not discriminate between E. granulosus originating from central Queensland macropod marsupials, Australian mainland sheep or United Kingdom sheep. Furthermore, sheep cyst material from Tasmania and the Australian mainland was indistinguishable using this approach. As a result of this DNA analysis, the existence of three distinct strains of E. granulosus in Australia, previously described on the basis of morphological, biochemical and developmental differences, may require re-evaluation. 相似文献
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J Bussenius CM Blazey N Aay NK Anand A Arcalas T Baik OJ Bowles CA Buhr S Costanzo JK Curtis SC Defina L Dubenko TS Heuer P Huang C Jaeger A Joshi AR Kennedy AI Kim K Lara J Lee J Li JC Lougheed S Ma S Malek JC Manalo JF Martini G McGrath M Nicoll JM Nuss M Pack CJ Peto TH Tsang L Wang SW Womble M Yakes W Zhang KD Rice 《Bioorganic & medicinal chemistry letters》2012,22(17):5396-5404
With structural guidance, tropane-derived HTS hits were modified to optimize for HSP90 inhibition and a desirable in vivo profile. Through an iterative SAR development process 12i (XL888) was discovered and shown to reduce HSP90 client protein content in PD studies. Furthermore, efficacy experiments performed in a NCI-N87 mouse xenograft model demonstrated tumor regression in some dosing regimens. 相似文献
78.
Soil warming alters nitrogen cycling in a New England forest: implications for ecosystem function and structure 总被引:5,自引:0,他引:5
Butler SM Melillo JM Johnson JE Mohan J Steudler PA Lux H Burrows E Smith RM Vario CL Scott L Hill TD Aponte N Bowles F 《Oecologia》2012,168(3):819-828
Global climate change is expected to affect terrestrial ecosystems in a variety of ways. Some of the more well-studied effects include the biogeochemical feedbacks to the climate system that can either increase or decrease the atmospheric load of greenhouse gases such as carbon dioxide and nitrous oxide. Less well-studied are the effects of climate change on the linkages between soil and plant processes. Here, we report the effects of soil warming on these linkages observed in a large field manipulation of a deciduous forest in southern New England, USA, where soil was continuously warmed 5°C above ambient for 7 years. Over this period, we have observed significant changes to the nitrogen cycle that have the potential to affect tree species composition in the long term. Since the start of the experiment, we have documented a 45% average annual increase in net nitrogen mineralization and a three-fold increase in nitrification such that in years 5 through 7, 25% of the nitrogen mineralized is then nitrified. The warming-induced increase of available nitrogen resulted in increases in the foliar nitrogen content and the relative growth rate of trees in the warmed area. Acer rubrum (red maple) trees have responded the most after 7 years of warming, with the greatest increases in both foliar nitrogen content and relative growth rates. Our study suggests that considering species-specific responses to increases in nitrogen availability and changes in nitrogen form is important in predicting future forest composition and feedbacks to the climate system. 相似文献
79.
The PCNA-associated factor KIAA0101/p15(PAF) binds the potential tumor suppressor product p33ING1b 总被引:1,自引:0,他引:1
Simpson F Lammerts van Bueren K Butterfield N Bennetts JS Bowles J Adolphe C Simms LA Young J Walsh MD Leggett B Fowles LF Wicking C 《Experimental cell research》2006,312(1):73-85
The KIAA0101/p15(PAF)/OEATC-1 protein was initially isolated in a yeast two-hybrid screen for proliferating cell nuclear antigen (PCNA) binding partners, and was shown to bind PCNA competitively with the cell cycle regulator p21(WAF). PCNA is involved in DNA replication and damage repair. Using polyclonal antisera raised against a p15(PAF) fusion protein, we have shown that in a range of mammalian tumor and non-tumor cell lines the endogenous p15(PAF) protein localises to the nucleus and the mitochondria. Under normal conditions no co-localisation with PCNA could be detected, however following exposure to UV it was possible to co-immunoprecipitate p15(PAF) and PCNA from a number of cell lines, suggesting a UV-enhanced association of the two proteins. Overexpression of p15(PAF) in mammalian cells was also found to protect cells from UV-induced cell death. Based on similarities between the behaviour of p15(PAF) and the potential tumor suppressor product p33ING1b, we have further shown that these two proteins interact in the same complex in cell cultures. This suggests that p15(PAF) forms part of a larger protein complex potentially involved in the regulation of DNA repair, apoptosis and cell cycle progression. 相似文献
80.
Priest DM Ambrose SJ Vaistij FE Elias L Higgins GS Ross AR Abrams SR Bowles DJ 《The Plant journal : for cell and molecular biology》2006,46(3):492-502
A glucosyltransferase (GT) of Arabidopsis, UGT71B6, recognizing the naturally occurring enantiomer of abscisic acid (ABA) in vitro, has been used to disturb ABA homeostasis in planta. Transgenic plants constitutively overexpressing UGT71B6 (71B6-OE) have been analysed for changes in ABA and the related ABA metabolites abscisic acid glucose ester (ABA-GE), phaseic acid (PA), dihydrophaseic acid (DPA), 7'-hydroxyABA and neo-phaseic acid. Overexpression of the GT led to massive accumulation of ABA-GE and reduced levels of the oxidative metabolites PA and DPA, but had marginal effect on levels of free ABA. The control of ABA homeostasis, as reflected in levels of the different metabolites, differed in the 71B6-OEs whether the plants were grown under standard conditions or subjected to wilt stress. The impact of increased glucosylation of ABA on ABA-related phenotypes has also been assessed. Increased glucosylation of ABA led to phenotypic changes in post-germinative growth. The use of two structural analogues of ABA, known to have biological activity but to differ in their capacity to act as substrates for 71B6 in vitro, confirmed that the phenotypic changes arose specifically from the increased glucosylation caused by overexpression of 71B6. The phenotype and profile of ABA and related metabolites in a knockout line of 71B6, relative to wild type, has been assessed during Arabidopsis development and following stress treatments. The lack of major changes in these parameters is discussed in the context of functional redundancy of the multigene family of GTs in Arabidopsis. 相似文献