RepA-WH1 prionoid: Clues from bacteria on factors governing phase transitions in amyloidogenesis

10 p.-1 fig.In bacterial plasmids, Rep proteins initiate DNA replication by undergoing a structural transformation coupled to dimer dissociation. Amyloidogenesis of the ‘winged-helix’ N-terminal domain of RepA (WH1) is triggered in vitro upon binding to plasmid-specific DNA sequences, and occurs at the bacterial nucleoid in vivo. Amyloid fibers are made of distorted RepA-WH1 monomers that assemble as single or double intertwined tubular protofilaments. RepA-WH1 causes in E. coli an amyloid proteinopathy, which is transmissible from mother to daughter cells, but not infectious, and enables conformational imprinting in vitro and in vivo; i.e. RepA-WH1 is a ‘prionoid’. Microfluidics allow the assessment of the intracellular dynamics of RepA-WH1: bacterial lineages maintain two types (strains-like) of RepA-WH1 amyloids, either multiple compact cytotoxic particles or a single aggregate with the appearance of a fluidized hydrogel that it is mildly detrimental to growth. The Hsp70 chaperone DnaK governs the phase transition between both types of RepA-WH1 aggregates in vivo, thus modulating the vertical propagation of the prionoid. Engineering chimeras between the Sup35p/[PSI*] prion and RepA-WH1 generates [REP-PSI*], a synthetic prion exhibiting strong and weak phenotypic variants in yeast. These recent findings on a synthetic, self-contained bacterial prionoid illuminate central issues of protein amyloidogenesis.Research on RepA-WH1 amyloids at CIBCSIC is currently financed by Spanish MINECO grants BIO2012-30852 and CSD2009-00088.Peer reviewe

A Bacterial Shortcut to Amyloidosis

21 p.-10 fig.The synthetic bacterial prionoid RepA-WH1 causes a vertically transmissible amyloid proteinopathy in Escherichia coli that inhibits growth and eventually kills the cells. Recent in vitro studies show that RepA-WH1 builds pores through model lipid membranes, suggesting a possible mechanism for bacterial cell death. By comparing acutely (A31V) and mildly (ΔN37) cytotoxic mutant variants of the protein, we report here that RepA-WH1(A31V) expression decreases the intracellular osmotic pressure and compromise bacterial viability under either aerobic or anaerobic conditions. Both are effects expected from threatening membrane integrity and are in agreement with findings on the impairment by RepA-WH1(A31V) of the proton motive force (PMF)-dependent transport of ions (Fe3+) and ATP1 synthesis. Systems approaches reveal that, in aerobiosis, the PMF-independent respiratory dehydrogenase NdhII is induced in response to the reduction in intracellular levels of iron. While NdhII is known to generate H2O2 as a by-product of the autoxidation of its FAD cofactor, key proteins in the defense against oxidative stress (OxyR, KatE), together with other stress-resistance factors, are sequestered by co-aggregation with the RepA-WH1(A31V) amyloid. Our findings suggest a route for RepA-WH1 toxicity in bacteria: a primary hit of damage to the membrane, compromising bionergetics, triggers a stroke of oxidative stress, which is exacerbated due to the aggregation-dependent inactivation of enzymes and transcription factors that enable the cellular response to such injury. The proteinopathy caused by the prion-like protein RepA-WH1 in bacteria recapitulates some of the core hallmarks of human amyloid diseases.This work has been supported by grants from Spanish AEI / EU-FEDER (BIO2012-30852, BIO2015- 68730-R and CSD2009-00088) and CSIC (i-LINK0889) to R.G. We acknowledge support of the publication fee by the CSIC Open Access Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe

Francisco del Castillo, autor de la fachada de la Chancillería de Granada

En la larga lista de personajes que ocuparon la presidencia de la Real Chancillería de Granada, en el primer siglo de su funcionamiento en esta ciudad, cada uno se distingui6 en su mandato por aspectos diferentes, lo que les hizo dejar una importante huella per sonal en la ciudad

Defining a novel domain that provides an essential contribution to site-specific interaction of Rep protein with DNA

15 p.-6 fig.An essential feature of replication initiation proteins is their ability to bind to DNA. In this work, we describe a new domain that contributes to a replication initiator sequence-specific interaction with DNA. Applying biochemical assays and structure prediction methods coupled with DNA-protein crosslinking, mass spectrometry, and construction and analysis of mutant proteins, we identified that the replication initiator of the broad host range plasmid RK2, in addition to two winged helix domains, contains a third DNA-binding domain. The phylogenetic analysis revealed that the composition of this unique domain is typical within the described TrfA-like protein family. Both in vitro and in vivo experiments involving the constructed TrfA mutant proteins showed that the newly identified domain is essential for the formation of the protein complex with DNA, contributes to the avidity for interaction with DNA, and the replication activity of the initiator. The analysis of mutant proteins, each containing a single substitution, showed that each of the three domains composing TrfA is essential for the formation of the protein complex with DNA. Furthermore, the new domain, along with the winged helix domains, contributes to the sequence specificity of replication initiator interaction within the plasmid replication origin.National Science Centre [2012/04/A/NZ1/00048 to I.K.;2017/26/D/NZ1/00239 to K.W.]; Foundation for Polish Science [TEAM, POIR.04.04.00-00-5C75/17-00 to I.K.]; International Institute of Molecular and Cell Biology in Warsaw (to J.M.B.); Ministerio de Economía,Industria y Competitividad (MINECO/AEI) [BIO2012-30852, RTI2018-094549-B-I00 to R.G.]. Funding for open access charge: Foundation for Polish Science [TEAM,POIR.04.04.00-00-5C75/17-00].Peer reviewe

Plan de comunicación interna y externa de la Facultad de Ciencias Sociales. Programa de Actividades Complementarias y de Difusión Cultural de la Facultad II

Memoria ID-0258. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

Effectiveness of a strategy that uses educational games to implement clinical practice guidelines among Spanish residents of family and community medicine (e-EDUCAGUIA project):A clinical trial by clusters

This study was funded by the Fondo de Investigaciones Sanitarias FIS Grant Number PI11/0477 ISCIII.-REDISSEC Proyecto RD12/0001/0012 AND FEDER Funding.Background: Clinical practice guidelines (CPGs) have been developed with the aim of helping health professionals, patients, and caregivers make decisions about their health care, using the best available evidence. In many cases, incorporation of these recommendations into clinical practice also implies a need for changes in routine clinical practice. Using educational games as a strategy for implementing recommendations among health professionals has been demonstrated to be effective in some studies; however, evidence is still scarce. The primary objective of this study is to assess the effectiveness of a teaching strategy for the implementation of CPGs using educational games (e-learning EDUCAGUIA) to improve knowledge and skills related to clinical decision-making by residents in family medicine. The primary objective will be evaluated at 1 and 6months after the intervention. The secondary objectives are to identify barriers and facilitators for the use of guidelines by residents of family medicine and to describe the educational strategies used by Spanish teaching units of family and community medicine to encourage implementation of CPGs. Methods/design: We propose a multicenter clinical trial with randomized allocation by clusters of family and community medicine teaching units in Spain. The sample size will be 394 residents (197 in each group), with the teaching units as the randomization unit and the residents comprising the analysis unit. For the intervention, both groups will receive an initial 1-h session on clinical practice guideline use and the usual dissemination strategy by e-mail. The intervention group (e-learning EDUCAGUIA) strategy will consist of educational games with hypothetical clinical scenarios in a virtual environment. The primary outcome will be the score obtained by the residents on evaluation questionnaires for each clinical practice guideline. Other included variables will be the sociodemographic and training variables of the residents and the teaching unit characteristics. The statistical analysis will consist of a descriptive analysis of variables and a baseline comparison of both groups. For the primary outcome analysis, an average score comparison of hypothetical scenario questionnaires between the EDUCAGUIA intervention group and the control group will be performed at 1 and 6months post-intervention, using 95% confidence intervals. A linear multilevel regression will be used to adjust the model. Discussion: The identification of effective teaching strategies will facilitate the incorporation of available knowledge into clinical practice that could eventually improve patient outcomes. The inclusion of information technologies as teaching tools permits greater learning autonomy and allows deeper instructor participation in the monitoring and supervision of residents. The long-term impact of this strategy is unknown; however, because it is aimed at professionals undergoing training and it addresses prevalent health problems, a small effect can be of great relevance. Trial registration: ClinicalTrials.gov: NCT02210442.Publisher PDFPeer reviewe

Vegetation and fire dynamics during the last 4000 years in the Cabañeros National Park (central Spain)

The Holocene vegetation dynamics of low- and mid-altitude areas of inland Iberia remain largely unknown, masking possible legacy effects of past land-use on current and future ecosystem trajectories. Here we present a 4000-year long palaeoecological record (pollen, spores, microscopic charcoal) from a mire located in the Cabañeros National Park (Toledo Mountains, central Spain), a region with key conservation challenges due to ongoing land-use changes. We reconstruct late Holocene vegetation history and assess the extent to which climate, land-use and disturbances played a role in the observed changes. Our results show that oak (Quercus) woodlands have been the main forested community of the Toledo Mountains over millennia, with deciduous Quercus pyrenaica and Quercus faginea more abundant than evergreen Quercus ilex and Quercus suber, particularly on the humid soils of the valley bottoms. Deciduous oak woodlands spread during drier periods replacing hygrophilous communities (Betula, Salix, hygrophilous Ericaceae) on the edges of the mire, and could cope with fire disturbance variability under dry conditions (e.g. ca. 3800–3000–1850–1050 BC- and 1300–100 cal BP–AD 650–1850-) as suggested by regional palaeoclimatic reconstructions. Pollen and coprophilous fungi data suggest that enhanced fire occurrence at ca. 1300–100 cal BP (AD 650–1850) was due to deliberate burning by local people to promote pastoral and arable farming at the expense of woodlands/shrublands under dry conditions. While historical archives date the onset of strong human impact on the vegetation of Cabañeros to the period at and after the Ecclesiastical Confiscation (ca. 150–100 cal BP, AD 1800–1850), our palaeoecological data reveal that land-use was already intense during the Arab period (ca. 1250–900 cal BP, AD 700–1050) and particularly marked during the subsequent City of Toledo's rule (ca. 700–150 cal BP, AD 1250–1800). Finally, we hypothesize that persistent groundwater discharge allowed the mires of the Toledo Mountains to act as interglacial hydrologic microrefugia for some hygrophilous woody plants (Betula, Myrica gale, Erica tetralix) during pronounced dry spells over the past millennia

75 años como referente de la investigación agraria y medioambiental española en condiciones de clima mediterráneo [Sitio Web]

1 .pdf con imagen de acceso al “website”, su url y los créditos relacionados con su creación y diseño.-- Créditos: Organización, Estación Experimental de Aula Dei (EEAD-CSIC); Dirección, Jesús Val Falcón; Coordinación, Ana Álvarez-Fernandez, Jorge Álvaro-Fuentes, Ernesto Igartua; Contenido, Anunciación Abadía, Javier Abadía, Carlos Albiñana, Miguel Alfonso, Arancha Arbeloa, Raúl Arbués, Isabel Armillas, Manuel Becana, Santiago Beguería, Carmen Castañeda, Ana Castillo, José Cavero, Bruno Contreras, Azahara Díaz, Edgar García, Elena García, Juan Manuel Gascuñana, Leticia Gaspar, Yolanda Gogorcena, Juan Herrero, Victoria Lafuente, María Victoria López, Juan Antonio Marín, José Martínez, José Carlos Martínez-Giménez, Ana Pilar Mata, Manuel Matamoros, Pierre Mignard, María Ángeles Moreno, Paula Murillo, Ana Navas, Antonio Pérez, Rafael Picorel, María Pilar Vallés, Irene Villar, Inmaculada Yruela, Nery Zapata, Isabel Zarazaga; Diseño y programación: DigitalWorks (Juanjo Ascaso y Asun Dieste); Vídeo, Delegación del CSIC en Aragón (Sara Gutiérrez y Yolanda Hernáiz); Fotografía, Archivo EEAD-CSIC, Anunciación Abadía, Jorge Álvaro-Fuentes, Arancha Arbeloa, Juanjo Ascaso, Santiago Beguería, Elena García, Ernesto Igartua, Ignasi Iglesias, José Manuel Lasa, José Carlos Martínez-Giménez, Pierre Mignard, María Ángeles Moreno, Rubén Sancho, Kosana Suvocarev, María Pilar Vallés, Nery Zapata."Sitio web" de nueva creación y conmemorativo del 75 Aniversario de la EEAD-CSIC que contiene: 1) Foto esférica de su personal en activo; 2) Recopilación de sus hitos históricos más destacados, en orden cronológico; 3) Un vídeo con participación de su personal y muestra de algunas de sus instalaciones; 4) Un mapa con la distribución geográfica de los egresado del Instituto; 5) Algunas fotos, destacando las tomadas a su personal en las celebraciones del 25 y 50 Aniversarios de la EEAD-CSIC.Presentado durante la "Jornada. 75 Aniversario EEAD-CSIC (Zaragoza, Patio de la Infanta. 30 octubre 2019)".Financiación: CSIC, Vicepresidencia Adjunta de Organización y Cultura Científica.N

Un motivo clave en la proteína Orc4p para el ensamblaje del complejo iniciador de la replicación en S. cerevisae

Leída en la Universidad Complutense de Madrid. Facultad de Ciencias Biológicas el 11-17-2008; 134 págs.Beca Formación de Personal Investigador Ministerio de Ciencia e Innovación (BES-2004-5221)Peer reviewe

Antitoxin ε Reverses Toxin ζ-Facilitated Ampicillin Dormants

© 2020 by the authors.Toxin-antitoxin (TA) modules are ubiquitous in bacteria, but their biological importance in stress adaptation remains a matter of debate. The inactive ζ-ε2-ζ TA complex is composed of one labile ε2 antitoxin dimer flanked by two stable ζ toxin monomers. Free toxin ζ reduces the ATP and GTP levels, increases the (p)ppGpp and c-di-AMP pool, inactivates a fraction of uridine diphosphate-N-acetylglucosamine, and induces reversible dormancy. A small subpopulation, however, survives toxin action. Here, employing a genetic orthogonal control of ζ and ε levels, the fate of bacteriophage SPP1 infection was analyzed. Toxin ζ induces an active slow-growth state that halts SPP1 amplification, but it re-starts after antitoxin expression rather than promoting abortive infection. Toxin ζ-induced and toxin-facilitated ampicillin (Amp) dormants have been revisited. Transient toxin ζ expression causes a metabolic heterogeneity that induces toxin and Amp dormancy over a long window of time rather than cell persistence. Antitoxin ε expression, by reversing ζ activities, facilitates the exit of Amp-induced dormancy both in rec+ and recA cells. Our findings argue that an unexploited target to fight against antibiotic persistence is to disrupt toxin-antitoxin interactions.This research was funded by the Spanish Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación (MCI/AEI)/FEDER, EU) PGC2018-097054-B-I00 to J.C.A.Peer reviewe