Noves troballes en el llevat Saccharomyces cerevisiae

Investigadors de la UAB, en col·laboració amb la Universitat de Stellenbosch (Sudàfrica), acaben de descriure l'estructura de l'enzim PPC descarboxilasa (PPCDC) en el llevat Saccharomyces cerevisiae, organisme d'enorme interès biotecnològic i excel·lent model per a la investigació biològica. Els científics han comprovat que aquesta estructura difereix substancialment de la que hi ha en els humans, el que, juntament amb el seu caràcter d'enzim essencial, el converteix en una potencial diana terapèutica.Investigadores de la UAB, en colaboración con la Universidad de Stellenbosch (Sudáfrica), acaban de describir la estructura del enzima PPC descarboxilasa, (PPCDC), en la levadura Saccharomyces cerevisiae, organismo de enorme interés biotecnológico y excelente modelo para la investigación biológica. Los científicos han comprobado que ésta difiere sustancialmente de la que tiene en los humanos, lo que, junto a su carácter de enzima esencial, la convierte en una potencial diana terapéutica.Researchers at UAB in collaboration with the University of Stellenbosch, South Africa, have discovered the structure of the PPC descarboxilase (PPCDC) enzyme present in the yeast Saccharomyces cerevisiae, a very important organism in biotechnology and an excellent model for biological research. Scientists have verified that its structure differs substantially from that found in humans, which, in addition to its characteristic as an essential enzyme, makes it a potential therapeutic target

Els efectes de la manca de potassi a la cèl·lula

Els efectes de la manca de potassi, un catió primordial en la majoria dels éssers vius, en les cèl·lules del llevat Saccharomyces cerevisiae ha estat estudiada per un grup d'investigadors de la UAB. L'escassetat d'aquest element pot afectar diversos aspectes de la fisiologia de la cèl·lula, alguns dels quals encara desconeguts. Aquesta investigació en revela noves funcions que poden ser extrapolades també a plantes i animals.Los efectos de la falta de potasio, un catión primordial en la mayoría de los seres vivos, en las células de la levadura Saccharomyces cerevisiae han sido estudiados por un grupo de investigadores de la UAB. La escasez de este elemento puede afectar varios aspectos de la fisiología de la célula, algunos de los cuales todavía desconocidos. Esta investigación revela nuevas funciones que pueden ser extrapoladas también a plantas y animales

Una proteïna, tres funcions

Ja fa gairebé tres dècades el descobriment de proteïnes que podien realitzar dues funcions diferents va suposar un punt de ruptura en la percepció clàssica de la biologia molecular, desafiant el concepte "una proteïna, una funció". Recentment, un equip internacional liderat per investigadors de la UAB ha trobat en un llevat un gen que codifica una proteïna que realitza tres funcions, diferents però importants per mantenir l'estabilitat genòmica i evitar la ruptura del DNA.Hace ya casi tres décadas el descubrimiento de proteínas que podían realizar dos funciones diferentes supuso un punto de ruptura en la percepción clásica de la biología molecular, desafiando el concepto "una proteína, una función". Recientemente, un equipo internacional liderado por investigadores de la UAB ha encontrado en una levadura un gen que codifica una proteína que realiza tres funciones distintas, pero todas ellas importantes para mantener la estabilidad genómica y evitar la ruptura del DNA.Almost three decades ago,the discovery of proteins that could perform two different functions was a breaking point in the perception of classical molecular biology, changelling the concept of "one protein, one function". Recently, an international team lead by researchers from the UAB found a yeast gene encoding a protein that performs three different functions, important for maintaining genomic stability and prevent DNA breakdown

Els llevats com a organisme model de recerca en biologia

Els llevats, i en particular el llevat Saccharomyces cerevisiae, han estat durant molts anys un excel·lent organisme model per a estudis fonamentals en bioquímica, biologia cel·lular i genètica eucariòtica, i també per a la recerca aplicada. S. cerevisiae acumula una sèrie d'avantatges que no es troben en altres models, com un genoma compacte, una genètica senzilla i una manipulació molt fàcil, i és especialment adequat per a les aproximacions d'alt rendiment en genòmica, proteòmica i interactòmica. Per aquesta raó, és l'organisme d'elecció per desenvolupar i verificar noves tecnologies i per investigar processos biològics fonamentals i conservats evolutivament.Yeasts, and particularly the budding yeast Saccharomyces cerevisiae, have been for many years an outstanding model organism for fundamental studies in eukaryotic biochemistry, cell biology and genetics, as well as for applied research. S. cerevisiae accumulates a number of advantages that are not found in other models, such as a compact genome, straightforward genetics and easy manipulation, and it is particularly suitable for highthroughput genomic, proteomic and interactomic approaches. For that reason it is the organism of choice to develop and test new technologies and to investigate fundamental and evolutionarily conserved biological processes

Biochemical characterization of recombinant yeast PPZ1, a protein phosphatase involved in salt tolerance

AbstractThe Saccharomyces cerevisiae gene PPZ1 codes for a 692-residues protein that shows in its carboxyl-terminal half about 60% identity with the catalytic subunit of mammalian and yeast protein phosphatase-1 and that is involved in salt homeostasis. T The complete PPZ1 protein has been succesfully expressed as a soluble glutathione-S-transferase fusion protein. The recombinant protein, after purification by a single affinity chromatography step, displayed phosphatase activity towards a number of substrates, including myelin basic protein, histone 2A and casein, but was ineffective in dephosphorylating glycogen phosphorylase. It was also active towards p-nitrophenylphosphate. The activity was severalfold increased by the presence of Mn2+ ions and by limited trypsinolysis. The enzyme was inhibited by okadaic acid and microcystin-LR at concentrations comparable to what is found for type 1 protein phosphatase although it was much less sensitive to inhibitor-2. The recombinant protein was phosphorylated in vitro by cAMP-dependent protein kinase, protein kinase C and casein kinase-2. Phosphorylation affected preferentially sites located in the amino-terminal half of the protein and did not alter the activity of the phosphatase

Deportividad y violencia en el fútbol base : un programa de evaluación y de prevención de partidos de riesgo

This studys primary objective was to evaluate sportsmanship and violence in soccer matches. In order to do so, all the trainers and referees in one of the feeder teams categories of the Zaragoza and Vitoria Football Clubs took part as experts and judges in drafting a football match evaluation checklist. Two trainers and a referee used this checklist after each match to evaluate the degree of sportsmanlike/unsportsmanlike behaviours that had taken place. The results of the evaluations of all the matches in the 2005-2006 season show that parents and spectators displayed the most unsportsmanlike behaviours, followed by the same types of behaviour in players and trainers. There was a lower incidence of violent, unsportsmanlike behaviours. This studys second objective was to evaluate a protocol to prevent violent incidents during high-risk matches in the leagues second round. This process consisted in signing a collaboration agreement with the training staff of teams that had displayed violent behaviour in the leagues first round. The trainers of these teams were trained to hold meetings and conduct specific exercises during team training sessions to encourage parents and players to behave in a sportsmanlike manner. The results show the positive contribution of these protocols, not only in the absence of violent incidents during high-risk matches, but also in the higher scores on the football match evaluation checklist achieved by participant trainers during the leagues second round, compared with non-participant trainers in the same category

Genome-wide recruitment profiling of transcription factor Crz1 in response to high pH stress

Background: Exposure of the budding Saccharomyces cerevisiae to an alkaline environment produces a robust transcriptional response involving hundreds of genes. Part of this response is triggered by an almost immediate burst of calcium that activates the Ser/Thr protein phosphatase calcineurin. Activated calcineurin dephosphorylates the transcription factor (TF) Crz1, which moves to the nucleus and binds to calcineurin/Crz1 responsive gene promoters. In this work we present a genome-wide study of the binding of Crz1 to gene promoters in response to high pH stress. Results: Environmental alkalinization promoted a time-dependent recruitment of Crz1 to 152 intergenic regions, the vast majority between 1 and 5 min upon stress onset. Positional evaluation of the genomic coordinates combined with existing transcriptional studies allowed identifying 140 genes likely responsive to Crz1 regulation. Gene Ontology analysis confirmed the relevant impact of calcineurin/Crz1 on a set of genes involved in glucose utilization, and uncovered novel targets, such as genes responsible for trehalose metabolism. We also identified over a dozen of genes encoding TFs that are likely under the control of Crz1, suggesting a possible mechanism for amplification of the signal at the transcription level. Further analysis of the binding sites allowed refining the consensus sequence for Crz1 binding to gene promoters and the effect of chromatin accessibility in the timing of Crz1 recruitment to promoters. Conclusions: The present work defines at the genomic-wide level the kinetics of binding of Crz1 to gene promoters in response to alkaline stress, confirms diverse previously known Crz1 targets and identifies many putative novel ones. Because of the relevance of calcineurin/Crz1 in signaling diverse stress conditions, our data will contribute to understand the transcriptional response in other circumstances that also involve calcium signaling, such as exposition to sexual pheromones or saline stress

Ser/Thr protein phosphatases in fungi: structure, regulation and function

Reversible phospho-dephosphorylation of proteins is a major mechanism for the control of cellular functions. By large, Ser and Thr are the most frequently residues phosphorylated in eukaryotes. Removal of phosphate from these amino acids is catalyzed by a large family of well-conserved enzymes, collectively called Ser/Thr protein phosphatases. The activity of these enzymes has an enormous impact on cellular functioning. In this work we present the members of this family in S. cerevisiae and other fungal species, and review the most recent findings concerning their regulation and the roles they play in the most diverse aspects of cell biology