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Baptista J.M.,New University of Lisbon | Justino M.C.,New University of Lisbon | Melo A.M.P.,Institute Investigacao Cientifica Tropical | Teixeira M.,New University of Lisbon | Saraiva L.M.,New University of Lisbon
Journal of Bacteriology | Year: 2012

Mammalian cells of innate immunity respond to pathogen invasion by activating proteins that generate a burst of oxidative and nitrosative stress. Pathogens defend themselves from the toxic compounds by triggering a variety of detoxifying enzymes. Escherichia coli flavorubredoxin is a nitric oxide reductase that is expressed under nitrosative stress conditions. We report that in contrast to nitrosative stress alone, exposure to both nitrosative and oxidative stresses abolishes the expression of flavorubredoxin. Electron paramagnetic resonance (EPR) experiments showed that under these conditions, the iron center of the flavorubredoxin transcription activator NorR loses the ability to bind nitric oxide. Accordingly, triggering of the NorR ATPase activity, a requisite for flavorubredoxin activation, was impaired by treatment of the protein with the double stress. Studies of macrophages revealed that the contribution of flavorubredoxin to the survival of E. coli depends on the stage of macrophage infection and that the lack of protection observed at the early phase is related to inhibition of NorR activity by the oxidative burst. We propose that the time-dependent activation of flavorubredoxin contributes to the adaptation of E. coli to the different fluxes of hydrogen peroxide and nitric oxide to which the bacterium is subjected during the course of macrophage infection. © 2012, American Society for Microbiology.

The male is described by the first time for Lasiotheus Paclt, 1963 (Nicoletiidae: Atelurinae) upon a sample of L. nanus (Escherich, 1903) obtained in Gabon, from where the genus was previously unknown. The real independence of Lasiotheus relatively to Gastrotheus Casey, 1890 s.s. and to Pseudogastrotheus Mendes, 2003 (all previously considered under Gastrotheus Casey, 1890) is reinforced. Five tribes are recognized in Nicoletiidae (Atelurinae), characterized on morphological characteristics shared by groups of genera: Atelurini Remington, 1954, Atopatelurini n. tribe, Dinatelurini n. tribe, Dionychellini n. tribe and Grassiellini n. tribe. Identification keys are proposed to the ca. 70 genera today known in the subfamily. Copyright © 2012 · Magnolia Press.

Hernandez-Castellano L.E.,University of Las Palmas de Gran Canaria | Almeida A.M.,New University of Lisbon | Almeida A.M.,Institute Investigacao Cientifica Tropical | Castro N.,University of Las Palmas de Gran Canaria | Arguello A.,University of Las Palmas de Gran Canaria
Current Protein and Peptide Science | Year: 2014

In this review authors address colostrum proteins implications in different domestic ruminant species. The colostrogenesis process and how different factors, such as litter size or nutrition during gestation can alter the different components concentrations in colostrum are also reviewed. The different colostrum fractions will be described, focusing on high and low abundant proteins. This review describes the major function of such proteins and their role on the passive immune transfer and nutrition in the newborn animal. It will be also performed a comprehensive review on different techniques and commercial kits available for high abundant protein depletion in colostrum. We will finally focus on how proteomics has been used to address this issue and how it can contribute to the major questions about colostrum associated immunology.© 2014 Bentham Science Publishers.

Sousa P.M.F.,Institute Investigacao Cientifica Tropical | Sousa P.M.F.,New University of Lisbon | Videira M.A.M.,Institute Investigacao Cientifica Tropical | Melo A.M.P.,Institute Investigacao Cientifica Tropical
FEBS Letters | Year: 2013

The Escherichia coli formate:oxygen oxidoreductase supercomplex (FdOx) was investigated with respect to function and composition. Formate oxidoreductase activity was detected in blue native polyacrylamide gel electrophoresis (BN-PAGE) resolved membranes of E. coli, which were also capable of cyanide sensitive formate:oxygen oxidoreductase activity. The latter was compromised in strains devoid of specific oxygen reductases, particularly, in those devoid of cytochrome bo3 or bdI. A principal component analysis (PCA) integrating E. coli aerobic respiratory chain gene transcription, enzyme activity and growth dynamics was performed, correlating formate:oxygen oxidoreductase activity and the transcription of the genes encoding cytochromes bo3 and bdI, and corroborating previous evidence that associated these complexes in FdOx. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Agency: Cordis | Branch: FP7 | Program: CSA-SA | Phase: FP7-PEOPLE-2009-NIGHT | Award Amount: 84.69K | Year: 2010

Continuing the SettingTheStage project organized in 2009, scientists will be called again on stage to celebrate the Researchers Night 2010 not only through performing arts (incl. theatre) but also through sports. These media will allow scientists to express themselves, their visions and their work. SettingTheStage II brings back together entities from four major cities across Portugal (North, Centre, South) with the aim of creating multiple spaces where scientists and the public can actively engage in the reality of being a scientist. At the core of the project is a series of arts performances to be specifically produced for RN2010, designed to stimulate reflection, discussion and debate on topics related to researchers and their everyday lives: the power and limits of their research, the impact of their research in society. Researchers and arts performers will work together to produce several performances, aimed at different age groups. In the same way, researchers and the public will share and discuss scientific concepts linked to the sports activities that will be organized during the event. Themes for the activities will be, among others, linked to the celebration of the International Year of Biodiversity and the World Day of the Heart, which will be celebrated at the end of September. Artistic performances and sport activities will be complemented with interactive hands-on activities, from small experiments and demos for youngsters, to speed-dating sessions with scientists, science cafe/bar and visits to museums. Awareness will be achieved through a concerted marketing campaign, bringing together the expertise and resources of all partners involved, including the maintenance/updating of the 2009 project design/image, website and blog. SettingTheStage II brings back together a large number of partners involved in the 2009 edition committed to guarantee a successful action.

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