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991.
Tattoli I Lembo-Fazio L Nigro G Carneiro LA Ferraro E Rossi G Martino MC de Stefano ME Cecconi F Girardin SE Philpott DJ Bernardini ML 《Microbes and infection / Institut Pasteur》2008,10(10-11):1114-1123
Infected epithelial cells, which act as a first barrier against pathogens, seldom undergo apoptosis. Rather, infected epithelial cells undergo a slow cell death that displays hallmarks of necrosis. Here, we demonstrate that rapid intracellular lysis of Shigella flexneri, provoked by either the use of a diaminopimelic acid auxotroph mutant or treatment of infected cells with antibiotics of the beta-lactam family, resulted in a massive and rapid induction of apoptotic cell death. This intracellular bacteriolysis-mediated apoptotic death (IBAD) was characterized by the specific involvement of the mitochondrial-dependent cytochrome c/Apaf-1 axis that resulted in the activation of caspases-3, -6 and -9. Importantly, Bcl-2 family members and the NF-kappaB pathway seemed to be critical modulators of IBAD. Finally, we identified that IBAD was also triggered by Salmonella enterica serovar Typhimurium but not by the Gram-positive bacteria, Listeria monocytogenes. Together, our results demonstrate that, contrary to previous findings, epithelial cells are intrinsically able to mount an efficient apoptotic cell death response following infection. Indeed, apoptosis in normal circumstances is masked by powerful anti-apoptotic mechanisms, which are overcome in IBAD. Our results also uncover an unexpected consequence of the treatment of infected cells with certain classes of antibiotics. 相似文献
992.
Nascimento IP Dias WO Quintilio W Christ AP Moraes JF Vancetto MD Ribeiro-Dos-Santos G Raw I Leite LC 《Microbes and infection / Institut Pasteur》2008,10(2):198-202
The currently used pertussis vaccines are highly efficacious; however, neonates are susceptible to whooping cough up to the sixth month. In agreement, DTP-immunized neonate mice were not protected against intracerebral challenge with Bordetella pertussis. Neonate mice immunized with either DTP or a recombinant-BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin do not show a humoral immune response against PT. On the other hand, rBCG-Pertussis induces higher PT-specific IFN-gamma production and an increase in both IFN-gamma(+) and TNF-alpha(+)-CD4(+)-T cells than the whole cell pertussis vaccine and confers protection against a lethal intracerebral challenge with B. pertussis. 相似文献
993.
Aceves-Lara CA Trably E Bastidas-Oyenadel JR Ramirez I Latrille E Steyer JP 《Journal de la Société de Biologie》2008,202(3):177-189
This new century addresses several environmental challenges among which distribution of drinking water, global warming and availability of novel renewable energy sources to substitute for fossil fuels are of utmost importance. The last two concerns are closely related because the major part of carbon dioxide (CO(2)), considered as the main cause of the greenhouse effect, is widely produced from fossil fuel combustion. Renewable energy sources fully balanced in CO(2) are therefore of special interest, especially the issue of biological production from organic wastes. Among the possibilities of bioenergy production from wastes, two approaches are particularly interesting: The first one is relatively old and related to the production of biomethane by anaerobic digestion while the second one, more recent and innovative, relies on biohydrogen production by microbial ecosystems. 相似文献
994.
995.
Claudet J Osenberg CW Benedetti-Cecchi L Domenici P García-Charton JA Pérez-Ruzafa A Badalamenti F Bayle-Sempere J Brito A Bulleri F Culioli JM Dimech M Falcón JM Guala I Milazzo M Sánchez-Meca J Somerfield PJ Stobart B Vandeperre F Valle C Planes S 《Ecology letters》2008,11(5):481-489
Marine reserves are widely used throughout the world to prevent overfishing and conserve biodiversity, but uncertainties remain about their optimal design. The effects of marine reserves are heterogeneous. Despite theoretical findings, empirical studies have previously found no effect of size on the effectiveness of marine reserves in protecting commercial fish stocks. Using 58 datasets from 19 European marine reserves, we show that reserve size and age do matter: Increasing the size of the no-take zone increases the density of commercial fishes within the reserve compared with outside; whereas the size of the buffer zone has the opposite effect. Moreover, positive effects of marine reserve on commercial fish species and species richness are linked to the time elapsed since the establishment of the protection scheme. The reserve size-dependency of the response to protection has strong implications for the spatial management of coastal areas because marine reserves are used for spatial zoning. 相似文献
996.
We consider the problem of predicting cis-regulatory modules without knowledge of motifs. We formulate this problem in a pragmatic setting, and create over 30 new data sets, using Drosophila modules, to use as a 'benchmark'. We propose two new methods for the problem, and evaluate these, as well as two existing methods, on our benchmark. We find that the challenge of predicting cis-regulatory modules ab initio, without any input of relevant motifs, is a realizable goal. 相似文献
997.
Uri Keich Hong Gao Jeffrey S Garretson Anand Bhaskar Ivan Liachko Justin Donato Bik K Tye 《BMC bioinformatics》2008,9(1):372
Background
In analyzing the stability of DNA replication origins in Saccharomyces cerevisiae we faced the question whether one set of sequences is significantly enriched in the number and/or the quality of the matches of a particular position weight matrix relative to another set. 相似文献998.
Vladimir Paar Nenad Pavin Ivan Basar Marija Rosandić Matko Glunčić Nils Paar 《BMC bioinformatics》2008,9(1):466
Background
Identification of approximate tandem repeats is an important task of broad significance and still remains a challenging problem of computational genomics. Often there is no single best approach to periodicity detection and a combination of different methods may improve the prediction accuracy. Discrete Fourier transform (DFT) has been extensively used to study primary periodicities in DNA sequences. Here we investigate the application of DFT method to identify and study alphoid higher order repeats. 相似文献999.
Bacteria use protein phosphorylation to regulate all kinds of physiological processes. Protein phosphorylation plays a role in several key steps of the infection process of bacterial pathogens, such as adhesion to the host, triggering and regulation of pathogenic functions as well as biochemical warfare; scrambling the host signaling cascades and impairing its defense mechanisms. Recent phosphoproteomic studies indicate that the bacterial protein phosphorylation networks could be more complex than initially expected, comprising promiscuous kinases that regulate several distinct cellular functions by phosphorylating different protein substrates. Recent advances in protein labeling with stable isotopes in the field of quantitative mass spectrometry phosphoproteomics will enable us to chart the global phosphorylation networks and to understand the implication of protein phosphorylation in cellular regulation on the systems scale. For the study of bacterial pathogens, in particular, this research avenue will enable us to dissect phosphorylation-related events during different stages of infection and stimulate our efforts to find inhibitors for key kinases and phosphatases implicated therein. 相似文献
1000.
Protein dynamics is regulated by an elaborate interplay between different post-translational modifications. Ubiquitin and ubiquitin-like proteins (Ubls) are small proteins that are covalently conjugated to target proteins with important functional consequences. One such modifier is SUMO, which mainly modifies nuclear proteins. SUMO contains a unique N-terminal arm not present in ubiquitin and other Ubls, which functions in the formation of SUMO polymers. Here, we unambiguously show that serine 2 of the endogenous SUMO-1 N-terminal protrusion is phosphorylated in vivo using very high mass accuracy mass spectrometry at both the MS and the MS/MS level and complementary fragmentation techniques. Strikingly, we detected the same phosphorylation in yeast, Drosophila and human cells, suggesting an evolutionary conserved function for this modification. The nearly identical human SUMO-2 and SUMO-3 isoforms differ in serine 2; thus, only SUMO-3 could be phosphorylated at this position. Our finding that SUMO can be modified may point to an additional level of complexity through modifying a protein-modifier. 相似文献