71 research outputs found
Sequence-dependent cleavage site selection by RNase Z from the cyanobacterium synechocystis sp. PCC 6803
Biosynthesis of transfer RNA requires processing from longer precursors at the 5′- and 3′-ends. In eukaryotes, in archaea, and in those bacteria where the 3′-terminal CCA sequence is not encoded, 3′ processing is carried out by the endonuclease RNase Z, which cleaves after the discriminator nucleotide to generate a mature 3′-end ready for the addition of the CCA sequence. We have identified and cloned the gene coding for RNase Z in the cyanobacterium Synechocystis sp. PCC 6803. The gene has been expressed in Escherichia coli, and the recombinant protein was purified. The enzymatic activity of RNase Z from Synechocystis has been studied in vitro with a variety of substrates. The presence of C or CC after the discriminator nucleotide modifies the cleavage site of RNase Z so that it is displaced by one and two nucleotides to the 3′-side, respectively. The presence of the complete 3′-terminal CCA sequence in the precursor of the tRNA completely inhibits RNase Z activity. The inactive CCA-containing precursor binds to Synechocystis RNase Z with similar affinity than the mature tRNA. The properties of the enzyme described here could be related with the mechanism by which CCA is added in this organism, with the participation of two separate nucleotidyl transferases, one specific for the addition of C and another for the addition of A. This work is the first characterization of RNase Z from a cyanobacterium, and the first from an organism with two separate nucleotidyl transferases.Ministerio de Ciencia y TecnologÃa BMC2001–3789, BFU2004 – 00076/BMCJunta de AndalucÃa CVI21
Adaptación al espacio europeo de educación superior en la Diplomatura en Turismo: una experiencia piloto en la Universidad de Sevilla
E
ste trabajo parte de una experiencia piloto desarrollada en las asignaturas de Dirección de Operaciones de la Diplomatura en Turismo de la Universidad de Sevilla, con objeto de iniciar el proceso de adaptación a los requerimientos de la Declaración de Bolonia ante el proyecto de creación del Espacio Europeo de Educación Superior. Esta investigación se incluye en otra de mayor alcance en la que se analiza, de forma detallada, la experiencia piloto de implantación del Sistema de Créditos Europeo (ECTS ) en tres asignaturas impartidas por las autoras de este trabajo.T
his article begins with a pilot experience through the Operations Management subjects teaching in Tourism Degree in the University of Seville in order to adapt this subject to the Bolonia specifications and the creation of the European Higher Education Area. This research is part of an investigation that analyses the pilot experience of implementation of the European Credit Transfer and Acumulation System in three subjects teaching by the authors
Experiencia piloto de adaptación de las asignaturas de operaciones de la Diplomatura en Turismo de la Universidad de Sevilla al sistema ECTS
Este trabajo gira en torno a una experiencia piloto desarrollada en tres asignaturas de Dirección de Operaciones que forman parte de la Diplomatura en Turismo de la Universidad de Sevilla, con objeto de iniciar el proceso de adaptación al Sistema de Créditos Europeo (ECTS: European Credit Transfer and Accumulation System). Creemos que dicha experiencia puede ser útil a otros profesores que aún no hayan comenzado la adaptación de las asignaturas que imparten a los requerimientos para la creación del Espacio Europeo de Educación Superior (European Higher Education Area).This study deals with a pilot scheme conducted in Operations Management courses that are part of the Tourism studies at the University of Seville, with a view to initiating the process for adapting to the European Credit Transfer and Accumulation System (ECTS ). In our opinion this experience may be of use to other teachers that have still not adapted the subjects to the requirements that the creation of the European Higher Education Area entails
A positioned +1 nucleosome enhances promoter-proximal pausing
Chromatin distribution is not uniform along the human genome. In most genes there is a promoter-associated nucleosome free region (NFR) followed by an array of nucleosomes towards the gene body in which the first (+1) nucleosome is strongly positioned. The function of this characteristic chromatin distribution in transcription is not fully understood. Here we show in vivo that the +1 nucleosome plays a role in modulating RNA polymerase II (RNAPII) promoter-proximal pausing. When a +1 nucleosome is strongly positioned, elongating RNAPII has a tendency to stall at the promoter-proximal region, recruits more negative elongation factor (NELF) and produces less mRNA. The nucleosome-induced pause favors pre-mRNA quality control by promoting the addition of the cap to the nascent RNA. Moreover, the uncapped RNAs produced in the absence of a positioned nucleosome are degraded by the 5′-3′ exonuclease XRN2. Interestingly, reducing the levels of the chromatin remodeler ISWI factor SNF2H decreases +1 nucleosome positioning and increases RNAPII pause release. This work demonstrates a function for +1 nucleosome in regulation of transcription elongation, pre-mRNA processing and gene expression.España, Ministerio de EconomÃa y Competitividad BFU- 2011-2344
Neoplasia intraepitelial cervical en mujeres menores de 25 años
Fundamento: aunque la incidencia de lesiones preinvasivas del cervix ha sido mayor en mujeres de la tercera a cuarta década de la vida, en los últimos años se ha encontrando un número no despreciable de mujeres menores de 25 años afectadas por este tipo de lesiones de bajo o alto grado. Objetivo: describir el comportamiento de las neoplasias intraepiteliales cervicales diagnosticadas en mujeres menores de 25 años de edad, y tratadas con radiocirugÃa. Métodos: estudio retrospectivo y descriptivo de 67 pacientes menores de 25 años de edad, con diagnóstico de neoplasia intraepitelial cervical y tratadas por el método de radiocirugÃa en el Hospital General de Cienfuegos. Se analizaron las variables: edad, tipo de NIC, grado de la NIC y presencia de VPH. Resultados: el grupo más afectado fue el de las mujeres de 21 a 25 años de edad, portador del 70,4 % de lesiones. El 86, 56 % de las lesiones fue de alto grado. Las lesiones estuvieron asociadas con elevada frecuencia (88,05 %) a condiloma, evidencia histológica indirecta de la citotoxicidad por la infestación tisular del VPH. Conclusiones: La presencia de NIC en mujeres menores de 25 años de edad, se configura en nuestro medio como problema de salud. El presente estudio puede servir como sustrato para desarrollar investigaciones similares en varios lugares del paÃs, con la finalidad de aportar evidencia global que conduzca al cambio.</p
The chromatin remodeller CHD8 is required for E2F-dependent transcription activation of S-phase genes
The precise regulation of S-phase-specific genes is critical for cell proliferation. How the repressive chromatin configuration mediated by the retinoblastoma protein and repressor E2F factors changes at the G1/S transition to allow transcription activation is unclear. Here we show ChIP-on-chip studies that reveal that the chromatin remodeller CHD8 binds ∼2000 transcriptionally active promoters. The spectrum of CHD8 target genes was enriched in E2F-dependent genes. We found that CHD8 binds E2F-dependent promoters at the G1/S transition but not in quiescent cells. Consistently, CHD8 was required for G1/S-specific expression of these genes and for cell cycle re-entry on serum stimulation of quiescent cells. We also show that CHD8 interacts with E2F1 and, importantly, loading of E2F1 and E2F3, but not E2F4, onto S-specific promoters, requires CHD8. However, CHD8 recruiting is independent of these factors. Recruiting of MLL histone methyltransferase complexes to S-specific promoters was also severely impaired in the absence of CHD8. Furthermore, depletion of CHD8 abolished E2F1 overexpression-dependent S-phase stimulation of serum-starved cells, highlighting the essential role of CHD8 in E2F-dependent transcription activation
Genome-wide study of chromatin remodeling factor CHD8 role in transcription
1 página. Cold Spring Harbor Laboratory (CSHL) Meeting on Mechanisms of Eukaryotic Trasncription 2011. August 30 - september 3, 2011.CHD8 (Chromodomain-Helicase-DNA binding protein 8) is a member of the chromodomain helicase DNA-binding (CHD) subfamily of enzymes, which also belongs to the SNF2 family of ATP-dependent chromatin remodelers.Peer reviewe
DIAGNÓSTICO DEL CLIMA ORGANIZACIONAL DEL HOSPITAL DE LA MUJER ZACATECANA
Determinar el clima organizacional del Hospital de la Mujer Zacatecana. Estudio observacional, transversal y analÃtico, donde la selección de la muestra aleatoria fue de 80 trabajadores (médicos y enfermeras). El clima organizacional del nosocomio resultó no satisfactorio entre las cuatro dimensiones que lo conforman. Las dimensiones Liderazgo y Motivación obtuvieron porcentajes por debajo del 50 por ciento, evaluándose como no satisfactorias. Las dimensiones Reciprocidad y Participación se catalogaron de poco satisfactorias, sus porcentajes de respuestas a favor del clima estuvieron por arriba del 50 por ciento, pero por abajo de un 80 por ciento para haber sido consideradas como satisfactorias. Diagnosticado el clima del nosocomio se plantea llevar a cabo la retroalimentación de procesos y procedimientos orientados al logro de los objetivos dentro de la unidad con el fin de generar un ambiente de trabajo más agradable.  Absctract Determine the organizational climate of Zacatecas Women's Hospital. Observational, transversal and analytical, you select a random sample of 80 workers (doctors and nurses). The organizational climate of the hospital was unsatisfactory in four dimensions that comprise it. Leadership and Motivation dimensions percentages were below 50 percent, evaluated as unsatisfactory. The dimensions were classified reciprocity and participation of unsatisfactory, their response rates for climate were above 50 percent, but down from 80 percent to have been considered satisfactory. Hospital diagnosed the climate arises to carry out the feedback processes and procedures aimed at achieving the objectives within the unit to generate a more pleasant working environment. Palabras claves: Clima organizacional, hospital, personal médico y de enfermerÃa.
ConsultorÃa integral en una empresa fabricante de muebles de diseño en el municipio de Zapotlanejo
ITESO, A.C
The Cornelia de Lange Syndrome-associated factor NIPBL interacts with BRD4 ET domain for transcription control of a common set of genes
Mutations in NIPBL are the major cause of Cornelia de Lange Syndrome (CdLS). NIPBL is the cohesin-loading factor and has recently been associated with the BET (bromodomains and extra-terminal (ET) domain) proteins BRD2 and BRD4. Related to this, a CdLS-like phenotype has been described associated to BRD4 mutations. Here, we show direct interaction of NIPBL with different BET members in yeast, and selective interaction with BRD4 in cells, being the ET domain involved in the interaction. To understand the relationship between NIPBL and BET proteins, we have performed RNA-Seq expression analysis following depletion of the different proteins. Results indicate that genes regulated by NIPBL largely overlap with those regulated by BRD4 but not with those regulated by BRD2. ChIP-Seq analysis indicates preferential NIPBL occupancy at promoters, and knockdown experiments show mutual stabilization of NIPBL and BRD4 on co-regulated promoters. Moreover, human fibroblasts from CdLS probands with mutations in NIPBL show reduced BRD4 at co-occupied promoters. Functional analysis in vivo, using mutants of Drosophila melanogaster, confirmed the genetic interaction between Nipped-B and fs(1)h, the orthologs of human NIPBL and BRD4, respectively. Thus, we provide evidence for NIPBL and BRD4 cooperation in transcriptional regulation, which should contribute to explain the recently observed CdLS-like phenotype associated with BRD4 mutations.Ministry of Economy and Competitiveness (MINECO), Spain BFU2015-64721-
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