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Resumen del póster presentado a la EMBO Conference: Cell polarity and membrane dynamics, celebrada en Sant Feliu de Guixols (España) del 4 al 9 de junio de 2017., As an enveloped virus, HCMV exploits intracellular membranes for its assembly and release. We recently reported that HCMV induces the expression of the SNARE protein Syntaxin 3 (Stx3), which is required for virus production through a mechanism that involves late endosomes. Moreover, we have found that Stx3 mono-ubiquitination targets it to this compartment. Here we show that overexpression of a non-ubiquitinated Stx3 mutant (Stx3-5R) strongly inhibits infectious virus production. Stx3-5R not only reduced the expression of HCMV structural and non-structural proteins but also delayed the expression of the immediate-early gene product EA1. Using qPCR we found that transcript levels of the essential viral transactivators EA1 and EA2 were also reduced in the presence of Stx3-5R. We are currently studying the molecular mechanism that underlay this downregulation. Based on this we propose a novel role for Stx3 as a regulator of HCMV gene expression.

Objetivos: fazer uma revisão dos aspectos básicos da ultraestrutura do taquizoíto de Toxoplasma gondii, agente etiológico da toxoplasmose. Fonte de dados: os dados apresentados tomam como referência resultados recentes obtidos pelos principais grupos de pesquisadores no mundo, que se dedicam ao estudo do Toxoplasma gondii, incluindo-se dados do próprio grupo de autores. Síntese dos dados: os taquizoítos de Toxoplasma gondii são responsáveis pela fase aguda da infecção, penetrando ativamente, através do complexo apical, em células dos hospedeiros onde se multiplicam. São abordadas características ultraestruturais e moleculares particulares da película, do citoesqueleto, de organelas secretórias (róptrias, micronemas e grânulos densos) e não secretórias (apicoplasto) exclusivas do filo Apicomplexa, além das peculiaridades do núcleo, mitocôndria, acidocalcisomas, retículo endoplasmático e complexo de Golgi desses parasitos intracelulares. Conclusões: estas características confirmam que o sucesso nas etapas de adesão, invasão e multiplicação do parasito possui clara correlação com suas características morfofuncionais

Herbicides as Potential Chemotherapeutic Agents Against Parasitic Protozoa

Submitted by Lívia Oliveira (livia.oliveira2@hotmail.com) on 2012-06-25T14:34:33Z No. of bitstreams: 1 Plos One,v.7,n.3,e33440, 2012.pdf: 507586 bytes, checksum: 895174a86bdd2a2d9ebf6edac4726c60 (MD5) Rejected by Regina Mello(mrmello@inmetro.gov.br), reason: arquivo repetido on 2012-07-02T13:59:15Z (GMT) Submitted by Lívia Oliveira (livia.oliveira2@hotmail.com) on 2012-07-18T12:51:47Z No. of bitstreams: 1 Plos One,v.7,n.3,e33440, 2012.pdf: 507586 bytes, checksum: 895174a86bdd2a2d9ebf6edac4726c60 (MD5) Approved for entry into archive by Regina Mello(mrmello@inmetro.gov.br) on 2013-01-17T15:49:31Z (GMT) No. of bitstreams: 1 Plos One,v.7,n.3,e33440, 2012.pdf: 507586 bytes, checksum: 895174a86bdd2a2d9ebf6edac4726c60 (MD5) Made available in DSpace on 2013-01-17T15:49:31Z (GMT). No. of bitstreams: 1 Plos One,v.7,n.3,e33440, 2012.pdf: 507586 bytes, checksum: 895174a86bdd2a2d9ebf6edac4726c60 (MD5) Previous issue date: 2012 The invasive land snail Achatina fulica is one of the most damaging agricultural pests worldwide representing a potentially serious threat to natural ecosystems and human health. This species is known to carry parasites and harbors a dense and metabolically active microbial community; however, little is known about its diversity and composition. Here, we assessed for the first time the complexity of bacterial communities occurring in the digestive tracts of field-collected snails (FC) by using culture-independent molecular analysis. Crop and intestinal bacteria in FC were then compared to those from groups of snails that were reared in the laboratory (RL) on a sugarcane-based diet. Most of the sequences recovered were novel and related to those reported for herbivorous gut. Changes in the relative abundance of Bacteroidetes and Firmicutes were observed when the snails were fed a high-sugar diet, suggesting that the snail gut microbiota can influence the energy balance equation. Furthermore, this study represents a first step in gaining a better understanding of land snail gut microbiota and shows that this is a complex holobiont system containing diverse, abundant and active microbial communities. 6 p. : il.

Submitted by Lívia Oliveira (livia.oliveira2@hotmail.com) on 2012-06-28T16:23:37Z No. of bitstreams: 1 Garcia_2012.pdf: 1572444 bytes, checksum: 70c7fd3535d64524869d8286f0d2f82d (MD5) Approved for entry into archive by Regina Mello(mrmello@inmetro.gov.br) on 2012-06-28T16:30:08Z (GMT) No. of bitstreams: 1 Garcia_2012.pdf: 1572444 bytes, checksum: 70c7fd3535d64524869d8286f0d2f82d (MD5) Made available in DSpace on 2012-08-13T13:01:22Z (GMT). No. of bitstreams: 1 Garcia_2012.pdf: 1572444 bytes, checksum: 70c7fd3535d64524869d8286f0d2f82d (MD5) Previous issue date: 2012 Capsule production is common among bacterial species, but relatively rare in eukaryotic microorganisms. Members of the fungal Cryptococcus genus are known to produce capsules, which are major determinants of virulence in the highly pathogenic species Cryptococcus neoformans and Cryptococcus gattii. Although the lack of virulence of many species of the Cryptococcus genus can be explained solely by the lack of mammalian thermotolerance, it is uncertain whether the capsules from these organisms are comparable to those of the pathogenic cryptococci. In this study, we compared the characteristic of the capsule from the non-pathogenic environmental yeast Cryptococcus liquefaciens with that of C. neoformans. Microscopic observations revealed that C. liquefaciens has a capsule visible in India ink preparations that was also efficiently labeled by three antibodies generated to specific C. neoformans capsular antigens. Capsular polysaccharides of C. liquefaciens were incorporated onto the cell surface of acapsular C. neoformans mutant cells. Polysaccharide composition determinations in combination with confocal microscopy revealed that C. liquefaciens capsule consisted of mannose, xylose, glucose, glucuronic acid, galactose and N-acetylglucosamine. Physical chemical analysis of the C. liquefaciens polysaccharides in comparison with C. neoformans samples revealed significant differences in viscosity, elastic properties and macromolecular structure parameters of polysaccharide solutions such as rigidity, effective diameter, zeta potential and molecular mass, which nevertheless appeared to be characteristics of linear polysaccharides that also comprise capsular polysaccharide of C. neoformans. The environmental yeast, however, showed enhanced susceptibility to the antimicrobial activity of the environmental phagocytes, suggesting that the C. liquefaciens capsular components are insufficient in protecting yeast cells against killing by amoeba. These results suggest that capsular structures in pathogenic Cryptococcus species and environmental species share similar features, but also manifest significant difference that could influence their potential to virulence. 11 p. : il.

Made available in DSpace on 2022-04-29T06:01:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-01 The study was conducted at the Research Laboratory of Hydraulic and Irrigation Group in the Rural Engineering Department, Technical University of Madrid (Universidad Politecnica de Madrid), Madrid, Spain. Water temperatures of 20, 30, 40°C and system pressures often encountered in irrigation practices of 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 and 200 kPa were applied to determine the effects of different water temperatures and pressures on emitter discharge. Non-pressure compensating in-line emitter which has turbulent flow regime with a long-path (labyrinth), emitter discharge was 4 L h-1 at system pressure of 100 kPa according to the manufacturer recommended, was used. Emitters were spaced 20 cm along the drip laterals with 16 mm diameter. Discharge equations and coefficients of variation related to temperatures of 20, 30 and 40°C were obtained as q = 0.375H0.51, q = 0.358H0.52, q = 0.346H0.53 and 2.68, 2.09, 3.65, respectively. Discharge of the emitter was affected by different system pressures and increased as potentially (R = 0993-0996). In general, the emitter discharge increased with increasing temperature. However, especially in the common system pressures of 90-120 kPa, differences of obtained emitter discharges between the different water temperatures were not significant (1%). Suleyman Demirel University Agricultural Faculty Agricultural Structure and Irrigation Department, 32260, Isparta University of Estadual Paulista Júlio de Mesquita Filho Rural Engineering Department, 18603-970 Botucatu, Sao Paulo Technical University of Madrid (Universidad Politecnica de Madrid) Rural Engineering Department Hydraulic and Irrigation Group, 28040, Madrid University of Sao Paulo Department of Biosystem Engineering, 13418-900, Piracicaba, Sao Paulo University of Estadual Paulista Júlio de Mesquita Filho Rural Engineering Department, 18603-970 Botucatu, Sao Paulo

Submitted by Lívia Oliveira (livia.oliveira2@hotmail.com) on 2012-06-27T15:00:10Z No. of bitstreams: 1 Plos One,v.6,n.7,p.e22359,2011.pdf: 2088336 bytes, checksum: b90db6de1fd976cffa4d1e7d64f73793 (MD5) Approved for entry into archive by Regina Mello(mrmello@inmetro.gov.br) on 2012-06-27T17:23:26Z (GMT) No. of bitstreams: 1 Plos One,v.6,n.7,p.e22359,2011.pdf: 2088336 bytes, checksum: b90db6de1fd976cffa4d1e7d64f73793 (MD5) Made available in DSpace on 2012-06-27T18:22:08Z (GMT). No. of bitstreams: 1 Plos One,v.6,n.7,p.e22359,2011.pdf: 2088336 bytes, checksum: b90db6de1fd976cffa4d1e7d64f73793 (MD5) Previous issue date: 2011 Background: Reservosomes are lysosome-related organelles found in Trypanosoma cruzi epimastigotes. They represent the last step in epimastigote endocytic route, accumulating a set of proteins and enzymes related to protein digestion and lipid metabolism. The reservosome matrix contains planar membranes, vesicles and lipid inclusions. Some of the latter may assume rectangular or sword-shaped crystalloid forms surrounded by a phospholipid monolayer, resembling the cholesterol crystals in foam cells. Methodology/Principal Findings: Using Nile Red fluorimetry and fluorescence microscopy, as well as electron microscopy, we have established a direct correlation between serum concentration in culture medium and the presence of crystalloid lipid inclusions. Starting from a reservosome purified fraction, we have developed a fractionation protocol to isolate lipid inclusions. Gas-chromatography mass-spectrometry (GC-MS) analysis revealed that lipid inclusions are composed mainly by cholesterol and cholesterol esters. Moreover, when the parasites with crystalloid lipid-loaded reservosomes were maintained in serum free medium for 48 hours the inclusions disappeared almost completely, including the sword shaped ones. Conclusions/Significance: Taken together, our results suggest that epimastigote forms of T. cruzi store high amounts of neutral lipids from extracellular medium, mostly cholesterol or cholesterol esters inside reservosomes. Interestingly, the parasites are able to disassemble the reservosome cholesterol crystalloid inclusions when submitted to serum starvation. 12 p. : il.

Submitted by Lívia Oliveira (livia.oliveira2@hotmail.com) on 2012-06-22T13:18:03Z No. of bitstreams: 1 Plos One,v.6,n11, e27276, 2011.pdf: 1347454 bytes, checksum: b0ee3f52902baf6ce0e14aa8450c325d (MD5) Approved for entry into archive by Regina Mello(mrmello@inmetro.gov.br) on 2012-06-25T16:18:11Z (GMT) No. of bitstreams: 1 Plos One,v.6,n11, e27276, 2011.pdf: 1347454 bytes, checksum: b0ee3f52902baf6ce0e14aa8450c325d (MD5) Made available in DSpace on 2012-06-27T18:32:38Z (GMT). No. of bitstreams: 1 Plos One,v.6,n11, e27276, 2011.pdf: 1347454 bytes, checksum: b0ee3f52902baf6ce0e14aa8450c325d (MD5) Previous issue date: 2011 Background: The yolk of insect eggs is a cellular domain specialized in the storage of reserve components for embryo development. The reserve macromolecules are stored in different organelles and their interactions with the embryo cells are mostly unknown. Acidocalcisomes are lysosome-related organelles characterized by their acidic nature, high electron density and large content of polyphosphate bound to several cations. In this work, we report the presence of acidocalcisome-like organelles in eggs of the insect vector Rhodnius prolixus. Methodology/Principal findings: Characterization of the elemental composition of electron-dense vesicles by electron probe X-ray microanalysis revealed a composition similar to that previously described for acidocalcisomes. Following subcellular fractionation experiments, fractions enriched in acidocalcisomes were obtained and characterized. Immunofluorescence showed that polyphosphate polymers and the vacuolar proton translocating pyrophosphatase (V-H+-PPase, considered as a marker for acidocalcisomes) are found in the same vesicles and that these organelles are mainly localized in the egg cortex. Polyphosphate quantification showed that acidocalcisomes contain a significant amount of polyphosphate detected at day-0 eggs. Elemental analyses of the egg fractions showed that 24.560.65% of the egg calcium are also stored in such organelles. During embryogenesis, incubation of acidocalcisomes with acridine orange showed that these organelles are acidified at day-3 (coinciding with the period of yolk mobilization) and polyphosphate quantification showed that the levels of polyphosphate tend to decrease during early embryogenesis, being approximately 30% lower at day-3 compared to day-0 eggs. Conclusions: We found that acidocalcisomes are present in the eggs and are the main storage compartments of polyphosphate and calcium in the egg yolk. As such components have been shown to be involved in a series of dynamic events that may control embryo growth, results reveal the potential involvement of a novel organelle in the storage and mobilization of inorganic elements to the embryo cells. 11 p. : il.

Submitted by Jonathan Barbosa (jon_crf@hotmail.com) on 2012-02-29T12:24:36Z No. of bitstreams: 1 Souza_2011.pdf: 4463774 bytes, checksum: 1087c84f106fb474e5514f9803de2564 (MD5) Rejected by Catarina Soares(cfsoares@inmetro.gov.br), reason: Corrigir nomes dos autores na referencia bibliografica on 2012-03-15T18:14:33Z (GMT) Submitted by Jonathan Barbosa (jon_crf@hotmail.com) on 2012-03-16T12:56:36Z No. of bitstreams: 1 Souza_2011.pdf: 4463774 bytes, checksum: 1087c84f106fb474e5514f9803de2564 (MD5) Approved for entry into archive by Regina Mello(mrmello@inmetro.gov.br) on 2012-06-28T17:27:50Z (GMT) No. of bitstreams: 1 Souza_2011.pdf: 4463774 bytes, checksum: 1087c84f106fb474e5514f9803de2564 (MD5) Made available in DSpace on 2012-08-13T13:06:00Z (GMT). No. of bitstreams: 1 Souza_2011.pdf: 4463774 bytes, checksum: 1087c84f106fb474e5514f9803de2564 (MD5) Previous issue date: 2011 Cellulases from thermophiles are capable of cleaving sugar chains from cellulose efficiently at high temperatures. The thermo-resistant Cel9A-68 cellulase possesses two important domains: CBM and a catalytic domain connected by a Pro/Ser/Thr rich linker. These domains act cooperatively to allow efficient catalysis. Despite exhaustive efforts to characterize cellulase binding and mechanism of action, a detailed description of the cellulose intrinsic flexibility is still lacking. From computational simulations we studied the temperature influence on the enzyme plasticity, prior to substrate binding. Interestingly, we observed an enhancement of collective motions at high temperatures. These motions are the most representative and describe an intrinsic hinge bending transition. A detailed analysis of these motions revealed an interdomain approximation where D459 and G460, located at the linker region, are the hinge residues. Therefore, we propose a new putative site for mutagenesis targeting the modulation of such conformational transition that may be crucial for activity. 12 p. : il.