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991.
Nucleolar binding sequences of the ribosomal protein S6e family reside in evolutionary highly conserved peptide clusters 总被引:1,自引:0,他引:1
Kundu-Michalik S Bisotti MA Lipsius E Bauche A Kruppa A Klokow T Kammler G Kruppa J 《Molecular biology and evolution》2008,25(3):580-590
Proteomic analyses of the nucleolus have revealed almost 700 functionally diverse proteins implicated in ribosome biogenesis, nucleolar assembly, and regulation of vital cellular processes. However, this nucleolar inventory has not unveiled a specific consensus motif necessary for nucleolar binding. The ribosomal protein family characterized by their basic nature should exhibit distinct binding sequences that enable interactions with the rRNA precursor molecules facilitating subunit assembly. We succeeded in delineating 2 minimal nucleolar binding sequences of human ribosomal protein S6 by fusing S6 cDNA fragments to the 5' end of the LacZ gene and subsequently detecting the intracellular localization of the beta-galactosidase fusion proteins. Nobis1 (nucleolar binding sequence 1), comprising of 4 highly conserved amino acid clusters separated by glycine or proline, functions independently of the 3 authentic nuclear localization signals (NLSs). Nobis2 consists of 2 conserved peptide clusters and requires the authentic NLS2 in its native context. Similarly, we deduced from previous publications that the single Nobis of ribosomal protein S25 is also highly conserved. The functional protein domain organization of the ribosomal protein S6e family consists of 3 modules: NLS, Nobis, and the C-terminal serine cluster of the phosphorylation sites. This modular structure is evolutionary conserved in vertebrates, invertebrates, and fungi. Remarkably, nucleolar binding sequences of small and large ribosomal proteins reside in peptide clusters conserved over millions of years. 相似文献
992.
993.
Cancer chemopreventive agents block the transformation of normal cells and/or suppress the promotion of premalignant cells to malignant cells. Certain agents may achieve these objectives by modulating xenobiotic biotransformation, protecting cellular elements from oxidative damage, or promoting a more differentiated phenotype in target cells. Conversely, various cancer chemopreventive agents can encourage apoptosis in premalignant and malignant cells in vivo and/or in vitro, which is conceivably another anticancer mechanism. Furthermore, it is evident that many of these apoptogenic agents function as prooxidants in vitro. The constitutive intracellular redox environment dictates a cell's response to an agent that alters this environment. Thus, it is highly probable that normal cells, through adaption, could acquire resistance to transformation via exposure to a chemopreventive agent that promotes oxidative stress or disrupts the normal redox tone of these cells. In contrast, transformed cells, which typically endure an oxidizing intracellular environment, would ultimately succumb to apoptosis due to an uncontrollable production of reactive oxygen species caused by the same agent. Here, we provide evidence to support the hypothesis that reactive oxygen species and cellular redox tone are exploitable targets in cancer chemoprevention via the stimulation of cytoprotection in normal cells and/or the induction of apoptosis in transformed cells. 相似文献
994.
Edgar Botero Carlos Naranjo Julián Aguirre 《The International Journal of Life Cycle Assessment》2008,13(2):172-174
Background, Aims and Scope In the world there are more than thirty LCA software products, but they do not have inventories or an evaluation method either
with regional applicability, especially for Colombia. A special software for Life Cycle Assessment and the Environmental Performance
Evaluation has been developed, which considers the environmental impacts generated by products during their life cycle and
processes involving productive activities. It accounts with inventories applicable to Colombia, for processes and services
like electrical energy production, transport and waste disposition. The Ecoscarcity evaluation method was adapted to Colombia
with national legislation and agreements for polluting reduction signed by country and the EPI (Environmental Points of Impact)
was established for 353 substances.
Methods The software allows users to use the methodology which corresponds to the standard ISO 14030 and 14040 directives. The database
uses the SPOLD international format. For ApeironPro software, database information used from monitoring air emissions and
effluents on factories in the region were realized by the Environmental Research Group from Pontificia Bolivariana University
and secondary type information has been obtained starting from studies realized by environmental organizations and factories
in the country which are interested in the management of quality environmental indicators. The antiquity of the information
was restricted from the last 5 years, 1998 to 2003, in order to possess temporal representativity. The Ecoscarcity method
uses information of the Environmental Ministry and Environmental Institutes of Colombia for the actual current load (F), and
target norm for total load (Fk), using information with national legislation and agreements for polluting reduction signed by the respective countries.
The software was designed in Web ambience with the database in MySQL, while the programming language was JAVA from Sun Microsystem.
Results The software has inventories for energy (electricity from coal, natural gas, fuel oil, hydroelectricity) transport (mean air,
truck, motor bus), processes (plastics, rubber, sugar, paints production, detergent production, combustion in heaters, foundry
of copper, iron, gold), waste disposal (incineration and landfill).
Discussion The Ecoscarcity method was analyzed for seven impact categories: climate change, acidification, stratospheric ozone depletion,
photo-oxidant formation, eutrophication, ecotoxicity and depletion of abiotic resources (coal, oil, natural gas, copper, nickel).
Conclusions For Colombia, the highest environmental impact is associated with the ozone layer depletion (235.7 Ecopoints/g) while the
lowest is associated with depletion of coal (8.6 × 10−7 Ecopoints/g), although this is reasonable since Colombia is the tenth largest producer of coal in the world.
Recommendations and Perspectives Latin America and Colombia need more inventories for their processes and to identify the more significant environmental impacts
of their industries. This work is an initial step in the research about Life Cycle Assessment and can also improve the work
in ecolabels for Colombia. 相似文献
995.
Anke Batsch Andrea Noetel Christian Fork Anita Urban Daliborka Lazic Tina Lucas Julia Pietsch Andreas Lazar Edgar Schömig Dirk Gründemann 《BMC bioinformatics》2008,9(1):95
Background
In real-time PCR, it is necessary to consider the efficiency of amplification (EA) of amplicons in order to determine initial target levels properly. EAs can be deduced from standard curves, but these involve extra effort and cost and may yield invalid EAs. Alternatively, EA can be extracted from individual fluorescence curves. Unfortunately, this is not reliable enough. 相似文献996.
Viruses lack self-propulsion. To move in multi-cellular hosts they must therefore manipulate infected cells. Herpesviruses provide an archetype for many aspects of host manipulation, but only for alpha-herpesviruses in is there much information about they move. Other herpesviruses are not necessarily the same. Here we show that Murine gamma-herpesvirus-68 (MHV-68) induces the outgrowth of long, branched plasma membrane fronds to create an intercellular network for virion traffic. The fronds were actin-based and RhoA-dependent. Time-lapse imaging showed that the infected cell surface became highly motile and that virions moved on the fronds. This plasma membrane remodelling was driven by the cytoplasmic tail of gp48, a MHV-68 glycoprotein previously implicated in intercellular viral spread. The MHV-68 ORF58 was also required, but its role was simply transporting gp48 to the plasma membrane, since a gp48 mutant exported without ORF58 did not require ORF58 to form membrane fronds either. Together, gp48/ORF58 were sufficient to induce fronds in transfected cells, as were the homologous BDLF2/BMRF2 of Epstein-Barr virus. Gp48/ORF58 therefore represents a conserved module by which gamma-herpesviruses rearrange cellular actin to increase intercellular contacts and thereby promote their spread. 相似文献
997.
Oil palm cultivation is frequently cited as a major threat to tropical biodiversity as it is centered on some of the world's most biodiverse regions. In this report, Web of Science was used to find papers on oil palm published since 1970, which were assigned to different subject categories to visualize their research focus. Recent years have seen a broadening in the scope of research, with a slight growth in publications on the environment and a dramatic increase in those on biofuel. Despite this, less than 1% of publications are related to biodiversity and species conservation. In the context of global vegetable oil markets, palm oil and soyabean account for over 60% of production but are the subject of less than 10% of research. Much more work must be done to establish the impacts of habitat conversion to oil palm plantation on biodiversity. Results from such studies are crucial for informing conservation strategies and ensuring sustainable management of plantations. 相似文献
998.
Rhodes KE Gekas C Wang Y Lux CT Francis CS Chan DN Conway S Orkin SH Yoder MC Mikkola HK 《Cell Stem Cell》2008,2(3):252-263
The mouse placenta was unveiled as an important reservoir for hematopoietic stem cells (HSCs), yet the origin of placental HSCs was unknown. By tracking developing HSCs by expression of Runx1-lacZ and CD41, we have found that HSCs emerge in large vessels in the placenta. Analysis of Ncx1(-/-) embryos, which lack a heartbeat, verified that HSC development is initiated in the placental vasculature independent of blood flow. However, fewer CD41+ hematopoietic cells were found in Ncx1(-/-) placentas than in controls, implying that some HSCs/progenitors colonize the placenta via circulation and/or HSC emergence is compromised without blood flow. Importantly, placentas from Ncx1(-/-) embryos possessed equal potential to generate myelo-erythroid and B and T lymphoid cells upon explant culture, verifying intact multilineage hematopoietic potential, characteristic of developing HSCs. These data suggest that, in addition to providing a niche for a large pool of HSCs prior to liver colonization, the placenta is a true site of HSC generation. 相似文献
999.
Ernesto San-Blas Mariangel Luzardo Edgar Portillo Yvan Fuenmayor Brynelly Bastidas 《BioControl》2017,62(6):847-855
Fungus gnats (FG) have been reported in Venezuelan greenhouses recently. Bradysia difformis Frey (Diptera, Mycetophilidae) was found attacking Daisy gerbera plants [Gerbera sp. L. (Asterales: Asteraceae)] and many other crops in the country causing serious damages. Heterorhabditis amazonensis Andaló et al. (Rhabditida: Heterorhabditidae), was used to assess the mortality of larvae and adults of FG, number of invader nematodes per larvae and to compare the mortality of FG using nematodes and/or ciromazine under laboratory conditions. In a commercial flower farm, different doses of these nematodes were applied for eight weeks to control FG. The results showed 95% of mortality of the B. difformis larvae under laboratory conditions and performed better in the field when 50,000 nematodes were applied in every pot as a base dose to initiate a control programme. According to our results, H. amazonensis has the potential to become a regular organism for controlling fungus gnat larvae in tropical greenhouses. 相似文献
1000.
Sylvia Caiuby Novaes Edgar Teodoro da Cunha 《Visual Anthropology: Published in cooperation with the Commission on Visual Anthropology》2017,30(2):105-146
Although rarely mentioned in English-language texts, Rituais de Festas Borôro has long been acknowledged as a masterpiece of early ethnographic film in the French and Brazilian literature. Shot in 1916 by a Brazilian army officer, Luiz Thomaz Reis, and released in 1917, the film is mainly about the funeral ceremony of the Bororo, an indigenous people of Central Brazil. Here we contrast this work with other ethnographic films of the period and suggest that it has a strong claim to be seen as the first ethnographic documentary in the modern sense of the term. We also consider the political circumstances that led to the filming in this particular form, its status as an ethnographic account of the funeral, and its place in the personal filmography of Luiz Thomaz Reis. 相似文献