40 research outputs found
Aprendizaje autónomo del Laboratorio de Química Inorgánica mediante el uso de TICs
Se ha creado un Entorno Virtual de Enseñanza y Aprendizaje (EVEA) circunscrito a la realización de prácticas en el Laboratorio de Química Inorgánica orientado a incrementar el grado de interacción entre el alumno con algún tipo de dificultad auditiva o dificultad idiomática y el profesor o el resto de sus compañeros mediante el uso conjunto del material elaborado y el uso de sistemas basados en redes sociales, mensajerías
Interactions of Kid–Kis toxin–antitoxin complexes with the parD operator-promoter region of plasmid R1 are piloted by the Kis antitoxin and tuned by the stoichiometry of Kid–Kis oligomers
The parD operon of Escherichia coli plasmid R1 encodes a toxin–antitoxin system, which is involved in plasmid stabilization. The toxin Kid inhibits cell growth by RNA degradation and its action is neutralized by the formation of a tight complex with the antitoxin Kis. A fascinating but poorly understood aspect of the kid–kis system is its autoregulation at the transcriptional level. Using macromolecular (tandem) mass spectrometry and DNA binding assays, we here demonstrate that Kis pilots the interaction of the Kid–Kis complex in the parD regulatory region and that two discrete Kis-binding regions are present on parD. The data clearly show that only when the Kis concentration equals or exceeds the Kid concentration a strong cooperative effect exists between strong DNA binding and Kid(2)–Kis(2)–Kid(2)–Kis(2) complex formation. We propose a model in which transcriptional repression of the parD operon is tuned by the relative molar ratio of the antitoxin and toxin proteins in solution. When the concentration of the toxin exceeds that of the antitoxin tight Kid(2)–Kis(2)–Kid(2) complexes are formed, which only neutralize the lethal activity of Kid. Upon increasing the Kis concentration, (Kid(2)–Kis(2))(n) complexes repress the kid–kis operon
La enseñanza en el máster de abogacía a través del análisis de casos reales de carácter multidisciplinar. Aprendizaje "a partir del estudio de razonamientos parciales temáticos"
Generar blog para publicaciones de alumnos del Máster Abogacía, con "entradas" dirigidas. Habría análisis desde varias disciplinas añadiéndose estudios con enfoque basado en otras áreas de conocimiento, generando interdisciplinariedad
Regulación e interacciones modulares del sistema parD del factor de resistencia a antibióticos R1
En esta tesis se estudia el sistema toxina-antitoxin parD del plásmido R1, un módulo auxiliar de mantenimiento del plásmido con un doble objetivo:1) analizar la regulación
transcripcional de este sistema y 2) estudiar el acoplamiento entre este módulo auxiliar de mantenimiento, sistema parD, y el módulo esencial de mantenimiento del plásmido denominado replicón básico. La introducción revisa la información relevante sobre lareplicación y el módulo toxina-antitoxina parD del plásmido R1 en el contexto general de los sistemas de mantenimiento de plásmidos bacterianos y de los objetivos de esta tesis doctoral
Transverse(Diff) theories of gravity
Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Teórica. Fecha de lectura: 20/12/201
Coupling between the Basic Replicon and the Kis-Kid Maintenance System of Plasmid R1: Modulation by Kis Antitoxin Levels and Involvement in Control of Plasmid Replication
kis-kid, the auxiliary maintenance system of plasmid R1 and copB, the auxiliary copy number control gene of this plasmid, contribute to increase plasmid replication efficiency in cells with lower than average copy number. It is thought that Kis antitoxin levels decrease in these cells and that this acts as the switch that activates the Kid toxin; activated Kid toxin reduces copB-mRNA levels and this increases RepA levels that increases plasmid copy number. In support of this model we now report that: (i) the Kis antitoxin levels do decrease in cells containing a mini-R1 plasmid carrying a repA mutation that reduces plasmid copy number; (ii) kid-dependent replication rescue is abolished in cells in which the Kis antitoxin levels or the CopB levels are increased. Unexpectedly we found that this coordination significantly increases both the copy number of the repA mutant and of the wt mini-R1 plasmid. This indicates that the coordination between plasmid replication functions and kis-kid system contributes significantly to control plasmid R1 replication.This study was founded by projects CSD2008-00013 and BFU2011-25939 of the Spanish Ministry
of Science and Innovation. Discussions related to this work with members of the group are kindly
acknowledged. The comments and corrections to the manuscript of Elizabeth Diago-Navarro are
kindly acknowledged.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)
Bacterial toxin-antitoxin systems targeting translation
10 p.-2 fig.Toxin-antitoxin systems (TAS) emerged more than 25 years ago and have since developed as an important field in molecular microbiology. TAS are autoregulated operons coding a stable toxin and an unstable antitoxin found in the plasmids and chromosomes of Bacteria and Archaea. The conditional activation of their toxins interferes with cell growth/viability and, depending on the context, can influence plasmid maintenance,stress management, bacterial persistence, cell differentiation and, it is likely also bacterial virulence. This review summarizes recent results on the parD system of plasmid R1 and on the chromosomal relBE systems
found in Escherichia coli and in Streptococcus pneumoniae with a focus on the RNase activity of their toxins,their regulation and their biomedical applications and implications.The authors acknowledge the financial support of the MICINN, the Spanish Ministry of Science and Innovation, (CSD2008-00013; BFU2008-
00179-E/BMC)Peer reviewe
The ribonucleolytic activity of the ribotoxin α-sarcin is not essential for in vitro protein biosynthesis inhibition
Fungal ribotoxins are toxic secreted ribonucleases that cleave a conserved single phosphodiester bond located at the sarcin/ricin loop of the larger rRNA. This cleavage inactivates ribosomes leading to protein biosynthesis inhibition and cell death. It has been proposed that interactions other than those found at the active site of ribotoxins are needed to explain their exquisite specific activity. The study presented shows the ability of a catalytically inactive α-sarcin mutant (H137Q) to bind eukaryotic ribosomes and interfere with in vitro protein biosynthesis. The results obtained are compatible with previous observations that α-sarcin can promote cell death by a mechanism that is independent of rRNA cleavage, expanding the potential set of activities performed by this family of toxins