Navegando por Autor "Mota, Bruno Eduardo Fernandes"

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Detailed search for protein kinase(s) involved in plasma membrane H+-ATPase activity regulation of yeast cells.
(2015) Pereira, Renata Rebeca; Castanheira, Diogo Dias; Teixeira, Janaina Aparecida; Bouillet, Leoneide Érica Maduro; Ribeiro, Erica Milena de Castro; Trópia, Maria José Magalhães; Alvarez, Florencia; Correa, Lygia Fátima da Mata; Mota, Bruno Eduardo Fernandes; Conceição, Luís Eduardo Fernandes Rodrigues da; Castro, Ieso de Miranda; Brandão, Rogélio Lopes
This study displays a screening using yeast strains deficient in protein kinases known to exist in Saccharomyces cerevisiae. From 95 viable single mutants, 20 mutants appear to be affected in the glucose-induced extracellular acidification. The mutants that are unaffected in calcium signaling were tested for their sensitivity to hygromycin B. Furthermore, we verified whether the remaining mutants produced enzymes that are appropriately incorporated at plasma membrane. Finally, we measure the kinetic properties of the enzyme in purified plasma membranes from glucose-starved as well as glucose-fermenting cells. We confirmed the kinase Ptk2 involvement in H+−ATPase regulation (increase of affinity for ATP). However, the identification of the kinase(s) responsible for phosphorylation that leads to an increase in Vmax appears to be more complex. Complementary experiments were performed to check how those protein kinases could be related to the control of the plasma membrane H+−ATPase and/or the potential membrane. In summary, our results did not permit us to identify the protein kinase(s) involved in regulating the catalytic efficiency of the plasma membrane H+−ATPase. Therefore, our results indicate that the current regulatory model based on the phosphorylation of two different sites located in the C-terminus tail of the enzyme could be inappropriate.
Variable flocculation profiles of yeast strains isolated from cachaça distilleries.
(2014) Alvarez, Florencia; Correa, Lygia Fátima da Mata; Araújo, Thalita Macedo; Mota, Bruno Eduardo Fernandes; Conceição, Luís Eduardo Fernandes Rodrigues da; Castro, Ieso de Miranda; Brandão, Rogélio Lopes
In cachaça production, the use of yeast cells as starters with predictable flocculation behavior facilitates the cell recovery at the end of each fermentation cycle. Therefore, the aim of this work was to explain the behavior of cachaça yeast strains in fermentation vats containing sugarcane through the determination of biochemical and molecular parameters associated with flocculation phenotypes. By analyzing thirteen cachaça yeast strains isolated from different distilleries, our results demonstrated that neither classic biochemical measurements (e.g., percentage of flocculation, EDTA sensitivity, cell surface hydrophobicity, and sugar residues on the cell wall) nor modern molecular approaches, such as polymerase chain reaction (PCR) and real-time PCR (q-PCR), were sufficient to distinctly classify the cachaça yeast strains according to their flocculation behavior. It seems that flocculation is indeed a strain-specific phenomenon that is difficult to explain and/or categorize by the available methodologies
Virulence in murine model shows the existence of two distinct populations of Brazilian vaccinia virus strains.
(2008) Ferreira, Jaqueline Maria Siqueira; Drumond, Betânia Paiva; Guedes, Maria Isabel Maldonado Coelho; Xavier, Marcelo Antônio Pascoal; Leite, Camila Megale Almeida; Arantes, Rosa Maria Esteves; Mota, Bruno Eduardo Fernandes; Abrahão, Jônatas Santos; Alves, Pedro Augusto; Oliveira, Fernando Meireles; Ferreira, Paulo César Peregrino; Bonjardim, Cláudio Antônio; Lobato, Zélia Inês Portela; Kroon, Erna Geessien
Brazilian Vaccinia virus had been isolated from sentinel mice, rodents and recently from humans, cows and calves during outbreaks on dairy farms in several rural areas in Brazil, leading to high economic and social impact. Some phylogenetic studies have demonstrated the existence of two different populations of Brazilian Vaccinia virus strains circulating in nature, but little is known about their biological characteristics. Therefore, our goal was to study the virulence pattern of seven Brazilian Vaccinia virus strains. Infected BALB/c mice were monitored for morbidity, mortality and viral replication in organs as trachea, lungs, heart, kidneys, liver, brain and spleen. Based on the virulence potential, the Brazilian Vaccinia virus strains were grouped into two groups. One group contained GP1V, VBH, SAV and BAV which caused disease and death in infected mice and the second one included ARAV, GP2V and PSTV which did not cause any clinical signals or death in infected BALB/ c mice. The subdivision of Brazilian Vaccinia virus strains into two groups is in agreement with previous genetic studies. Those data reinforce the existence of different populations circulating in Brazil regarding the genetic and virulence characteristics.