14 research outputs found

    DisA Limits RecG Activities at Stalled or Reversed Replication Forks

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    The DNA damage checkpoint protein DisA and the branch migration translocase RecG are implicated in the preservation of genome integrity in reviving haploid Bacillus subtilis spores. DisA synthesizes the essential cyclic 3′, 5′-diadenosine monophosphate (c-di-AMP) second messenger and such synthesis is suppressed upon replication perturbation. In vitro, c-di-AMP synthesis is suppressed when DisA binds DNA structures that mimic stalled or reversed forks (gapped forks or Holliday junctions [HJ]). RecG, which does not form a stable complex with DisA, unwinds branched intermediates, and in the presence of a limiting ATP concentration and HJ DNA, it blocks DisA-mediated c-di-AMP synthesis. DisA pre-bound to a stalled or reversed fork limits RecG-mediated ATP hydrolysis and DNA unwinding, but not if RecG is pre-bound to stalled or reversed forks. We propose that RecG-mediated fork remodeling is a genuine in vivo activity, and that DisA, as a molecular switch, limits RecG-mediated fork reversal and fork restoration. DisA and RecG might provide more time to process perturbed forks, avoiding genome breakage.This work was supported by the Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (MCIU/AEI)/FEDER PGC2018-097054-B-I00 to S.A. and J.C.A

    Presencia de Micromachismos en la sociedad española

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    El presente trabajo de fin de grado surge para dar respuesta sobre la presencia de los micromachismos en lasociedad española, y en la medida que la población está sensibilizada con ellos.El objetivo principal es identificar si existen o no micromachismos en la sociedad, así como de conseguir verlo sensibilizada que está la sociedad sobre ellos y el conocimiento que tienen acerca de los mismos. Paraconseguir este objetivo se ha desarrollado un estudio descriptivo transversal mediante una encuesta querecoge muestras de diferentes tipos de preguntas de identificación, sensibilización y consecuencias endiferentes ámbitos. Se ha realizado un análisis descriptivo y comparativo por género y edad. Además,también se mide como afecta en diferentes ámbitos, ya sea social, laboral, educativo…Por último, se presentan unas consideraciones finales, en las que se muestran la presencia de estosmicromachismos en la sociedad, el nivel de identificación y sensibilización con los mismos y sus repercusionesen ciertos ámbitos, así cómo las diferencias entre géneros y edad.<br /

    Relación estructura función en FAD sintetasas de origen procariótico

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    El FMN y el FAD se sintetizan en dos etapas secuenciales mediante la enzima FAD sintetasa (FADS) que, en procariotas, es una enzima bifuncional dividida en dos módulos, el dominio C-terminal, con actividad RF quinasa (RFK) y el N-terminal, con actividad FMN adenililtransferasa (FMNAT). Se propone la existencia de una estructura oligomérica, formada por un dímero de trímeros, que podría tener relevancia en el proceso catalítico. En este proyecto se han analizado los parámetros de unión de los ligandos y las actividades RFK y FMNAT de variantes mutadas de FADS de Corynebacterium ammoniagenes (CaFADS) en los residuos R66, K202, E203, D298 y E301, que están localizados en la interfase entre los dominios N- y C-terminal de cada dos monómeros que forman cada uno de los dos trímeros. Los mutantes presentan una estructura tridimensional similar a la de la proteína WT, y mantienen la capacidad de unión de los ligandos. El residuo R66, del módulo N-terminal es crítico para la actividad RFK del C-terminal y la unión de los ligandos, y podría colaborar junto con E268 como base catalítica en el módulo RFK. Los residuos K202 y E203, del módulo RFK, afectan a la unión de los ligandos y la actividad FMNAT, al influir en el bucle L8n del módulo FMNAT. El residuo D298, situado en el dominio C-terminal, es relevante para las actividades tanto RFK como FMNAT y el E301 está implicado en la unión de los ligandos en el sitio FMNAT de CaFADS. En conclusión, la influencia de la sustitución de residuos de un módulo en la actividad del otro apoya la hipótesis de que la forma oligomérica de CaFADS, en la que cada sitio activo estaría formado por residuos de su propio módulo y del módulo del protómero contiguo, juega un papel relevante durante la catálisis

    Eligibility criteria for Menopausal Hormone Therapy (MHT): a position statement from a consortium of scientific societies for the use of MHT in women with medical conditions. MHT Eligibility Criteria Group

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    This project aims to develop eligibility criteria for menopausal hormone therapy (MHT). The tool should be similar to those already established for contraception A consortium of scientific societies coordinated by the Spanish Menopause Society met to formulate recommendations for the use of MHT by women with medical conditions based on the best available evidence. The project was developed in two phases. As a first step, we conducted 14 systematic reviews and 32 metanalyses on the safety of MHT (in nine areas: age, time of menopause onset, treatment duration, women with thrombotic risk, women with a personal history of cardiovascular disease, women with metabolic syndrome, women with gastrointestinal diseases, survivors of breast cancer or of other cancers, and women who smoke) and on the most relevant pharmacological interactions with MHT. These systematic reviews and metanalyses helped inform a structured process in which a panel of experts defined the eligibility criteria according to a specific framework, which facilitated the discussion and development process. To unify the proposal, the following eligibility criteria have been defined in accordance with the WHO international nomenclature for the different alternatives for MHT (category 1, no restriction on the use of MHT; category 2, the benefits outweigh the risks; category 3, the risks generally outweigh the benefits; category 4, MHT should not be used). Quality was classified as high, moderate, low or very low, based on several factors (including risk of bias, inaccuracy, inconsistency, lack of directionality and publication bias). When no direct evidence was identified, but plausibility, clinical experience or indirect evidence were available, "Expert opinion" was categorized. For the first time, a set of eligibility criteria, based on clinical evidence and developed according to the most rigorous methodological tools, has been defined. This will provide health professionals with a powerful decision-making tool that can be used to manage menopausal symptoms

    Emerging trends in reassessing translation, conflict, and memory

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    New Approaches on Translation, Conflict, and Memory: Narratives of the Spanish Civil War and the Dictatorship is a collection of essays that endeavours to establish a new dialogue between translation, conflict, and memory studies. Focusing on cultural representations of the Spanish Civil War and the Franco Dictatorship, it explores the significance and the effect of translation within Spain and beyond. Drawing on fictional and non-fictional texts, reports from war zones, and audiovisual productions, the contributors to this volume examine the scope of translation in transmitting the conflict and the dictatorship from a contemporary perspective. Narratives produced during and after the Civil War and the dictatorship both in Spain and abroad have led to new debates arising from the reassessment of a conflict that continues to resonate

    Diverse Large HIV-1 Non-subtype B Clusters Are Spreading Among Men Who Have Sex With Men in Spain

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    In Western Europe, the HIV-1 epidemic among men who have sex with men (MSM) is dominated by subtype B. However, recently, other genetic forms have been reported to circulate in this population, as evidenced by their grouping in clusters predominantly comprising European individuals. Here we describe four large HIV-1 non-subtype B clusters spreading among MSM in Spain. Samples were collected in 9 regions. A pol fragment was amplified from plasma RNA or blood-extracted DNA. Phylogenetic analyses were performed via maximum likelihood, including database sequences of the same genetic forms as the identified clusters. Times and locations of the most recent common ancestors (MRCA) of clusters were estimated with a Bayesian method. Five large non-subtype B clusters associated with MSM were identified. The largest one, of F1 subtype, was reported previously. The other four were of CRF02_AG (CRF02_1; n = 115) and subtypes A1 (A1_1; n = 66), F1 (F1_3; n = 36), and C (C_7; n = 17). Most individuals belonging to them had been diagnosed of HIV-1 infection in the last 10 years. Each cluster comprised viruses from 3 to 8 Spanish regions and also comprised or was related to viruses from other countries: CRF02_1 comprised a Japanese subcluster and viruses from 8 other countries from Western Europe, Asia, and South America; A1_1 comprised viruses from Portugal, United Kingom, and United States, and was related to the A1 strain circulating in Greece, Albania and Cyprus; F1_3 was related to viruses from Romania; and C_7 comprised viruses from Portugal and was related to a virus from Mozambique. A subcluster within CRF02_1 was associated with heterosexual transmission. Near full-length genomes of each cluster were of uniform genetic form. Times of MRCAs of CRF02_1, A1_1, F1_3, and C_7 were estimated around 1986, 1989, 2013, and 1983, respectively. MRCA locations for CRF02_1 and A1_1 were uncertain (however initial expansions in Spain in Madrid and Vigo, respectively, were estimated) and were most probable in Bilbao, Spain, for F1_3 and Portugal for C_7. These results show that the HIV-1 epidemic among MSM in Spain is becoming increasingly diverse through the expansion of diverse non-subtype B clusters, comprising or related to viruses circulating in other countries

    Sak and Sak4 recombinases are required for bacteriophage replication in Staphylococcus aureus

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    Medical Research Council (UK) [MR/M003876/1]; Biotechnology and Biological Sciences Research Council (BBSRC, UK) [BB/N002873/1]; from European Union [ERC-ADG-2014 Proposal n° 670932 Dut-signal to J.R.P.]; MINECO (Spain) [BFU2012-39879-C02-02, BFU2015-67065-P to S.A.]; MINECO (Spain) [BIO2013-42619-P]; Valencian Government [Prometeo II/2014/029 to A.M.]. Funding for open access charge: Medical Research Council (UK).DNA-single strand annealing proteins (SSAPs) are recombinases frequently encoded in the genome of many bacteriophages. As SSAPs can promote homologous recombination among DNA substrates with an important degree of divergence, these enzymes are involved both in DNA repair and in the generation of phage mosaicisms. Here, analysing Sak and Sak4 as representatives of two different families of SSAPs present in phages infecting the clinically relevant bacterium Staphylococcus aureus, we demonstrate for the first time that these enzymes are absolutely required for phage reproduction. Deletion of the genes encoding these enzymes significantly reduced phage replication and the generation of infectious particles. Complementation studies revealed that these enzymes are required both in the donor (after prophage induction) and in the recipient strain (for infection). Moreover, our results indicated that to perform their function SSAPs require the activity of their cognate single strand binding (Ssb) proteins. Mutational studies demonstrated that the Ssb proteins are also required for phage replication, both in the donor and recipient strain. In summary, our results expand the functions attributed to the Sak and Sak4 proteins, and demonstrate that both SSAPs and Ssb proteins are essential for the life cycle of temperate staphylococcal phages.Publisher PDFPeer reviewe

    Sak and Sak4 recombinases are required for bacteriophage replication in <i>Staphylococcus aureus</i>

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    DNA-single strand annealing proteins (SSAPs) are recombinases frequently encoded in the genome of many bacteriophages. As SSAPs can promote homologous recombination among DNA substrates with an important degree of divergence, these enzymes are involved both in DNA repair and in the generation of phage mosaicisms. Here, analysing Sak and Sak4 as representatives of two different families of SSAPs present in phages infecting the clinically relevant bacterium Staphylococcus aureus, we demonstrate for the first time that these enzymes are absolutely required for phage reproduction. Deletion of the genes encoding these enzymes significantly reduced phage replication and the generation of infectious particles. Complementation studies revealed that these enzymes are required both in the donor (after prophage induction) and in the recipient strain (for infection). Moreover, our results indicated that to perform their function SSAPs require the activity of their cognate single strand binding (Ssb) proteins. Mutational studies demonstrated that the Ssb proteins are also required for phage replication, both in the donor and recipient strain. In summary, our results expand the functions attributed to the Sak and Sak4 proteins, and demonstrate that both SSAPs and Ssb proteins are essential for the life cycle of temperate staphylococcal phages
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