Cátia Bárria

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Micro-organisms react to a rapid temperature downshift by triggering a physiological response to ensure survival in unfavourable conditions. Adaptation includes changes in membrane composition and in the translation and transcription machineries. The cold shock response leads to a growth block and overall repression of translation; however, there is the(More)
Trypanosoma cruzi, a parasitic protozoan, is the etiological agent of Chagas disease, an endemic and neglected pathology in Latin America. It presents a life cycle that involves a hematophagous insect and man as well as domestic and wild mammals. The parasitic infection is not eliminated by the immune system of mammals; thus, the vertebrate host serves as a(More)
The isolation and preliminary characterization of a trypsin-like protease with high activity at 20 degrees C is described. This protease was isolated from Antarctic krill (Euphasia superba) by a two-step chromatography process and the use of zymogram analyses. The protease has a molecular weight of 30 kDa and a pI of 4.1. Its specific activity at 20 degrees(More)
The release of cholecystokinin from the dorsal and ventral region of the rat bed nucleus of stria terminalis was studied. Minislices from both regions were superfused with Krebs-Ringer-phosphate, and the cholecystokinin released into the physiological medium was concentrated previous to radioimmunoassay determination. For this purpose, cholecystokinin was(More)
In this study we employed the TAP tag purification method coupled with mass spectrometry analysis to identify proteins that co-purify with Escherichia coli RNase R during exponential growth and after temperature downshift. Our initial results suggested that RNase R can interact with bacterial ribosomes. We subsequently confirmed this result using sucrose(More)
In the last decade regulatory RNAs have emerged as powerful tools to regulate the expression of genes both in prokaryotes and in eukaryotes. RNases, by degrading these RNA molecules, control the right amount of regulatory RNAs, which is fundamental for an accurate regulation of gene expression in the cell. Remarkably the first antisense RNAs identified were(More)
Gene expression not only depends on the rate of transcription but is also largely controlled at the post-transcriptional level. Translation rate and mRNA decay greatly influence the final protein levels. Surveillance mechanisms are essential to ensure the quality of the RNA and proteins produced. Trans-translation is one of the most important systems in the(More)
Ribonucleases (RNases) are important factors for the establishment of virulence in an increasing number of pathogens. These enzymes are responsible for the maturation and degradation of RNA molecules, being key players in RNA metabolism. In this opinion we will focus on exoribonucleases from the RNB family, whose members are known to be involved in the(More)
of the chicken gut and a decreased ability to adhere and invade cells. Defects in motility are suggested to be responsible for many of the attenuation of the virulent traits of C. jejuni in the mutant pnp strain. Interestingly, the authors suggest that PNPase may be able to affect flagella-dependent motility by modulation of the NANA synthetase (neuB),(More)
Contaminated food is the source of many severe infections in humans. Recent advances in food science have discovered new foodborne pathogens and progressed in characterizing their biology, life cycle, and infection processes. All this knowledge has been contributing to prevent food contamination, and to develop new therapeutics to treat the infections(More)