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211.
Auxin receptors: a new role for F-box proteins 总被引:15,自引:0,他引:15
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Claudia Cerella Christiane Scherer Silvia Cristofanon Estelle Henry Awais Anwar Corinna Busch Mathias Montenarh Mario Dicato Claus Jacob Marc Diederich 《Apoptosis : an international journal on programmed cell death》2009,14(5):641-654
Naturally occurring organic sulfur compounds (OSCs), such as linear allylsulfides from Allium species, are attracting attention in cancer research, since several OSCs were shown to act beneficially both in chemoprevention
and in chemotherapy, while hardly exerting any harmful side effects. Hence, we investigated the possible role of different
OSCs in the treatment of leukemia. Thereby, we found that the compounds tested in this study induced apoptosis in U937 cells,
with an efficiency depending on the number of sulfides, and selected the most promising candidate, diallyltetrasulfide (Al2S4),
for detailed mechanistic studies. Here we show that Al2S4 induced an accumulation of cells in early mitosis (G2/M phase),
followed by the activation of caspase-dependent apoptosis. The compound counteracted different anti-apoptotic Bcl-2 family
members (Bcl-xL, phospho-Bad and Bcl-2), promoted activation of Bax and Bak and induced the release of cytochrome c into the cytoplasm. Treatment by Al2S4 let to the identification of early apoptotic events including Bcl-xL degradation,
Bak activation and release of cytochrome c followed by late events including Bcl-2 proteolysis, Bax activation, Bad dephosphorylation, caspase activation, nuclear fragmentation
and phosphatidylserine exposure.
Claudia Cerella and Christiane Scherer, both authors equally contributed to this work. 相似文献
215.
Pierre E. Galand Connie Lovejoy rew K. Hamilton R. Grant Ingram Estelle Pedneault Eddy C. Carmack 《Environmental microbiology》2009,11(4):971-980
Evidence of microbial zonation in the open ocean is rapidly accumulating, but while the distribution of communities is often described according to depth, the other physical factors structuring microbial diversity and function remain poorly understood. Here we identify three different water masses in the North Water (eastern Canadian Arctic), defined by distinct temperature and salinity characteristics, and show that they contained distinct archaeal communities. Moreover, we found that one of the water masses contained an increased abundance of the archaeal alpha-subunit of the ammonia monooxygenase gene ( amoA ) and accounted for 70% of the amoA gene detected overall. This indicates likely differences in putative biogeochemical capacities among different water masses. The ensemble of our results strongly suggest that the widely accepted view of depth stratification did not explain microbial diversity, but rather that parent water masses provide the framework for predicting communities and potential microbial function in an Arctic marine system. Our results emphasize that microbial distributions are strongly influenced by oceanic circulation, implying that shifting currents and water mass boundaries resulting from climate change may well impact patterns of microbial diversity by displacing whole biomes from their historic distributions. This relocation could have the potential to establish a substantially different geography of microbial-driven biogeochemical processes and associated oceanic production. 相似文献
216.
Jessica Normand Marie-Christine Ralet Jean-François Thibault Hélène Rogniaux Philippe Delavault Estelle Bonnin 《Applied microbiology and biotechnology》2010,86(2):577-588
A novel rhamnogalacturonase (RGase) acting on an acetylated substrate was detected in the commercial preparation Driselase,
an enzymatic mixture derived from the basidiomycete Irpex lacteus. The activity was isolated by hydrophobic interaction chromatography, gel filtration, and preparative isoelectric focusing,
resulting in the isolation of five different rhamnogalacturonan hydrolases exhibiting various isoelectric points from 6.2
to 7.7. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and mass spectrometry analyses after trypsin cleavage of
the five fractions revealed that the five rhamnogalacturonases have a molar mass of 55 kDa without any divergences in the
identified peptides. The RGase with a pI of 7.2 exhibited a pH optimum between 4.5 and 5 and a temperature optimum between
40°C and 50°C. Its mode of action was analyzed by mass spectrometry of the oligosaccharides produced after hydrolysis of acetylated
and nonacetylated rhamnogalacturonan. Oligomers esterified by an acetyl group on the reducing galacturonic acid residue or
fully acetylated were detected in the hydrolysate showing that the novel enzyme is able to bind acetylated galacturonic acid
in its active site. 相似文献
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218.
Aleš Snoj Branko Glamuzina Andrej Razpet John Zablocki Ivan Bogut Estelle Lerceteau-Köhler Naris Pojskić Simona Sušnik 《Hydrobiologia》2010,651(1):199-212
The genetic structure of Salmo dentex and its phylogenetic relations to sympatric salmonids in the Neretva and Skadar River basins were evaluated using mitochondrial
DNA (mtDNA) control region, eight microsatellites, and somatolactin (SL) gene. In the Neretva River basin of Bosnia–Herzegovina,
the results based on mtDNA analysis showed extensive haplotype sharing between S. marmoratus, S. dentex, and S. trutta, and were therefore not conclusive; however, F-statistics and assignment testing based on nuclear DNA markers indicated that S. dentex of the Neretva basin were grouped in a genetically unified cluster with S. marmoratus in the Neretva basin. Using the same analytical approach, S. dentex from the Skadar basin in Montenegro appeared to be genetically distinct from S. marmoratus in the same basin and indistinct from local S. trutta. Molecular data also indicated that S. dentex of the Neretva basin in Bosnia–Herzegovina are not closely related to S. dentex of the Skadar basin in Montenegro. Based on these results, we hypothesize S. dentex to be a particular life history form of S. marmoratus in the Neretva basin and of S. trutta in the Skadar basin. These results clearly demonstrate that S. dentex does not represent a monophyletic lineage and should not be considered a distinct species. 相似文献
219.
Duverger A Carré JM Jee J Leppla SH Cormet-Boyaka E Tang WJ Tomé D Boyaka PN 《Journal of immunology (Baltimore, Md. : 1950)》2010,185(10):5943-5952
We have shown that intranasal coapplication of Bacillus anthracis protective Ag (PA) together with a B. anthracis edema factor (EF) mutant having reduced adenylate cyclase activity (i.e., EF-S414N) enhances anti-PA Ab responses, but also acts as a mucosal adjuvant for coadministered unrelated Ags. To elucidate the role of edema toxin (EdTx) components in its adjuvanticity, we examined how a PA mutant lacking the ability to bind EF (PA-U7) or another mutant that allows the cellular uptake of EF, but fails to efficiently mediate its translocation into the cytosol (PA-dFF), would affect EdTx-induced adaptive immunity. Native EdTx promotes costimulatory molecule expression by macrophages and B lymphocytes, and a broad spectrum of cytokine responses by cervical lymph node cells in vitro. These effects were reduced or abrogated when cells were treated with EF plus PA-dFF, or PA-U7 instead of PA. We also intranasally immunized groups of mice with a recombinant fusion protein of Yersinia pestis F1 and LcrV Ags (F1-V) together with EdTx variants consisting of wild-type or mutants PA and EF. Analysis of serum and mucosal Ab responses against F1-V or EdTx components (i.e., PA and EF) revealed no adjuvant activity in mice that received PA-U7 instead of PA. In contrast, coimmunization with PA-dFF enhanced serum Ab responses. Finally, immunization with native PA and an EF mutant lacking adenylate cyclase activity (EF-K346R) failed to enhance Ab responses. In summary, a fully functional PA and a minimum of adenylate cyclase activity are needed for EdTx to act as a mucosal adjuvant. 相似文献
220.
Larisa C. Lotoski F. Estelle R. Simons Rishma Chooniedass Joel Liem Isha Ostopowich Allan B. Becker Kent T. HayGlass 《PloS one》2010,5(6)