46 research outputs found

    Aminoacyl-tRNA-Charged Eukaryotic Elongation Factor 1A Is the Bona Fide Substrate for Legionella pneumophila Effector Glucosyltransferases

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    Legionella pneumophila, which is the causative organism of LegionnaireĹ› disease, translocates numerous effector proteins into the host cell cytosol by a type IV secretion system during infection. Among the most potent effector proteins of Legionella are glucosyltransferases (lgt's), which selectively modify eukaryotic elongation factor (eEF) 1A at Ser-53 in the GTP binding domain. Glucosylation results in inhibition of protein synthesis. Here we show that in vitro glucosylation of yeast and mouse eEF1A by Lgt3 in the presence of the factors Phe-tRNAPhe and GTP was enhanced 150 and 590-fold, respectively. The glucosylation of eEF1A catalyzed by Lgt1 and 2 was increased about 70-fold. By comparison of uncharged tRNA with two distinct aminoacyl-tRNAs (His-tRNAHis and Phe-tRNAPhe) we could show that aminoacylation is crucial for Lgt-catalyzed glucosylation. Aminoacyl-tRNA had no effect on the enzymatic properties of lgt's and did not enhance the glucosylation rate of eEF1A truncation mutants, consisting of the GTPase domain only or of a 5 kDa peptide covering Ser-53 of eEF1A. Furthermore, binding of aminoacyl-tRNA to eEF1A was not altered by glucosylation. Taken together, our data suggest that the ternary complex, consisting of eEF1A, aminoacyl-tRNA and GTP, is the bona fide substrate for lgt's

    Outcome of Communication Training in Veterinary Studies: Influence on the Perception of the Relevance of Veterinary Competencies and Self-Assessment of Communication Skills

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    Since communication skills contribute significantly to professional success among veterinarians, there is a particular focus on developing communication classes in veterinary curricula. At Freie Universität Berlin, an e-learning course covering the basics of communication and a practical communication course based on role plays with and without simulation persons have been established. The outcome of these communication courses on the assessment of the relevance of several veterinary competencies and on the self-assessment of communication skills using the SE-12 questionnaire was investigated. For this purpose, students were surveyed before and after the e-learning course as well as before and after the practical course. Veterinarians were also surveyed on the relevance of veterinary competencies. The relevance of communicative competencies for professional success was rated significantly higher by the students after completing the practical course than by the other students and the veterinarians. Self-assessment of communication skills showed little increase after the e-learning course, but a significant increase after the practical course. Thus, an effective outcome of the communication classes was observed mainly after the practical course. However, the effect of the e-learning course cannot be ruled out since the students participating in the practical course have also completed the e-learning course beforehand

    Leave Me Alone With Your Symptoms! Social Exclusion at the Workplace Mediates the Relationship of Employee's Mental Illness and Sick Leave

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    Although a substantial part of employees suffers from a mental illness, the work situation of this population still is understudied. Previous research suggests that people with a mental illness experience discrimination in the workplace, which is known to have detrimental effects on health. Building on the stereotype content model and allostatic load theory, the present study investigated whether employees with a mental illness become socially excluded at the workplace and therefore show more days of sick leave. Overall, 86 employees diagnosed with a mental disorder were interviewed and completed online-surveys. Path analyses supported the hypotheses, yielding a serial mediation: The interview-rated severity of the mental disorder had an indirect effect on the days of sick leave, mediated by the symptomatic burden and the social exclusion at the workplace. In the light of the costs associated with absenteeism the present paper highlights the harmfulness of discrimination. Organizations and especially supervisors need to be attentive for signs of exclusion within their teams and try to counteract as early as possible

    Epstein-Barr Virus Stimulates Torque Teno Virus Replication: A Possible Relationship to Multiple Sclerosis

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    Viral infections have been implicated in the pathogenesis of multiple sclerosis. Epstein-Barr virus (EBV) has frequently been investigated as a possible candidate and torque teno virus (TTV) has also been discussed in this context. Nevertheless, mechanistic aspects remain unresolved. We report viral replication, as measured by genome amplification, as well as quantitative PCR of two TTV-HD14 isolates isolated from multiple sclerosis brain in a series of EBV-positive and -negative lymphoblastoid and Burkitt's lymphoma cell lines. Our results demonstrate the replication of both transfected TTV genomes up to day 21 post transfection in all the evaluated cell lines. Quantitative amplification indicates statistically significant enhanced TTV replication in the EBV-positive cell lines, including the EBV-converted BJAB line, in comparison to the EBV-negative Burkitt's lymphoma cell line BJAB. This suggests a helper effect of EBV infections in the replication of TTV. The present study provides information on a possible interaction of EBV and TTV in the etiology and progression of multiple sclerosis

    High-resolution transcriptomic and epigenetic profiling identifies novel regulators of COPD

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    Patients with chronic obstructive pulmonary disease (COPD) are still waiting for curative treatments. Considering its environmental cause, we hypothesized that COPD will be associated with altered epigenetic signaling in lung cells. We generated genome-wide DNA methylation maps at single CpG resolution of primary human lung fibroblasts (HLFs) across COPD stages. We show that the epigenetic landscape is changed early in COPD, with DNA methylation changes occurring predominantly in regulatory regions. RNA sequencing of matched fibroblasts demonstrated dysregulation of genes involved in proliferation, DNA repair, and extracellular matrix organization. Data integration identified 110 candidate regulators of disease phenotypes that were linked to fibroblast repair processes using phenotypic screens. Our study provides high-resolution multi-omic maps of HLFs across COPD stages. We reveal novel transcriptomic and epigenetic signatures associated with COPD onset and progression and identify new candidate regulators involved in the pathogenesis of chronic lung diseases. The presence of various epigenetic factors among the candidates demonstrates that epigenetic regulation in COPD is an exciting research field that holds promise for novel therapeutic avenues for patients

    „Der bösartige Mensch bedarf einer bösartigen Umgebung“.Paul Lehmanns "Die vertauschte Königin" und das Szenenbild des DEFA-Märchenfilms

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    Kinderfilme nahmen im Schaffen der DEFA-Studios einen besonderen Platz ein. Immerhin wurde ein Fünftel der Produktion Kinderfilmen gewidmet, von denen ein beachtlicher Teil Märchen waren. Der Film galt als Medium sozialistischer Erziehung. Innerhalb der - mal mehr mal weniger - restriktiven Vorgaben, leisteten auch die Szenenbildner ihren Anteil zu den pädagogisch wertvollen Streifen. Ihre Aufgabe bestand z. B. darin Charaktere mit Hilfe von Szenenbildern eindeutig zu zeichnen. Andererseits konnten die Szenenbildner der DEFA ihrer Fantasie selten so sehr freien Lauf lassen wie im Märchenfilm. Denn während in den meisten Spielfilmen das Postulat historischer Korrektheit galt um über Handlungsort und -zeit zu informieren und dabei historische wie auch soziale Zusammenhänge zu verdeutlichen, verlangten Märchen, die keine Zeit und keinen Ort haben, einzig nach Märchenhaftem. Es kommt daher zu wahrlich exotischen Kombinationen von Stilen verschiedenster Epochen und Länder, verbunden mit gänzlich fantastischen Elementen. Es entstanden Filmarchitekturen, die es zu keiner Zeit und an keinem Ort je gegeben hat. Am Beispiel des Märchenfilms Die Vertauschte Königin von 1984 mit den Szenenbildern von Paul Lehmann untersucht dieses Essay die Arbeit zwischen pädagogischem Auftrag und künstlerischer Freiheit

    Carbon, water and energy fluxes at the TERENO/ICOS ecosystem station Hohes Holz in Central Germany since 2015

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    Continuous measurements of carbon, water and energy fluxes are performed using the eddy covariance (EC) method in a mixed-beech forest ecosystem in central Germany (52° 5'12N, 11°13'20E, 193 m asl), accompanied by relevant abiotic measurements. The site was established in the Bode catchment as part of the TERENO Harz/Central German Lowland Observatory, a mesoscale water catchment within the Elbe river basin covering an area of approximately 3300 km2. The forest area Hohes Holz is the only larger forested area in the otherwise agriculturally intensively-farmed western part of the Magdeburger Börde with an area of about 1500 ha [Wollschläger et al., 2017]. The forest is a protected area with the centre (150 ha) being a nature reserve (Natura 2000) and is dominated by common beech (Fagus sylvatica L.), sessile oak (Quercus petraea) and hornbeam (Carpinus betulus L.) of about 90 years in age, an average tree height of 23.5 m and a stand density of 260 trees/ha. The long term average of annual precipitation is 563 mm and mean annual temperature is 9.1 °C (1981 – 2010 DWD station Ummendorf, #5158). The eddy covariance system consists of a CSAT-3 anemometer (Campbell Scientific Inc., Logan, UT, USA) and a LI-7500 gas analyser (Li-Cor Inc., Lincoln, NE, USA), established in 2014 in 49 m on a scaffolding tower within the research area. Data presented here comprise energy, water (H and LE), and carbon fluxes (NEE) from the EC-system since 2015 as well as gross primary productivity (GPP) and ecosystem respiration (Reco) derived from partitioning of NEE-data. Complimentary data from the turbulence data set and prioritized driver variables as a basis for ecosystem process analysis are added. High-frequency data (20Hz) were acquired with a Campbell data logger and the Eddymeas data acquisition software [Kolle and Rebmann, 2007]. Flux computation from high frequency raw data was performed with the Eddy-Pro® software (v. 7.0.6). After removing physically unrealistic flux values from the time series, subsequent post-processing steps such as estimating the u*-threshold, gap-filling and flux partitioning were performed according to Wutzler et al. [2018] with the REddyProc package. Full details of site instrumentation, metadata information and R-packages used for processing can be found in the supplementary material. Since January 2019 the site is approved as an ICOS ecosystem class 1 station (DE-HoH). ICOS standard procedures required an additional EC-setup consisting of a Gill HS-50 ultrasonic anemometer (Gill Instruments Ltd., Lymington, Hampshire, UK) and a LI-7200 gas analyser which runs in parallel to the above described system (see ICOS carbon portal: https://www.icos-cp.eu/data-products/ecosystem-release)

    Fluxes and related variables from EddyPro®-Output from eddy-covariance measurements above the forest ecosystem Hohes Holz in 2015

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    Continuous measurements of carbon, water and energy fluxes are performed using the eddy covariance (EC) method in a mixed-beech forest ecosystem in central Germany (52° 5'12N, 11°13'20E, 193 m asl), accompanied by relevant abiotic measurements. The site was established in the Bode catchment as part of the TERENO Harz/Central German Lowland Observatory, a mesoscale water catchment within the Elbe river basin covering an area of approximately 3300 km2. The forest area Hohes Holz is the only larger forested area in the otherwise agriculturally intensively-farmed western part of the Magdeburger Börde with an area of about 1500 ha [Wollschläger et al., 2017]. The forest is a protected area with the centre (150 ha) being a nature reserve (Natura 2000) and is dominated by common beech (Fagus sylvatica L.), sessile oak (Quercus petraea) and hornbeam (Carpinus betulus L.) of about 90 years in age, an average tree height of 23.5 m and a stand density of 260 trees/ha. The long term average of annual precipitation is 563 mm and mean annual temperature is 9.1 °C (1981 – 2010 DWD station Ummendorf, #5158). The eddy covariance system consists of a CSAT-3 anemometer (Campbell Scientific Inc., Logan, UT, USA) and a LI-7500 gas analyser (Li-Cor Inc., Lincoln, NE, USA), established in 2014 in 49 m on a scaffolding tower within the research area. Data presented here comprise energy, water (H and LE), and carbon fluxes (NEE) from the EC-system since 2015 as well as gross primary productivity (GPP) and ecosystem respiration (Reco) derived from partitioning of NEE-data. Complimentary data from the turbulence data set and prioritized driver variables as a basis for ecosystem process analysis are added. High-frequency data (20Hz) were acquired with a Campbell data logger and the Eddymeas data acquisition software [Kolle and Rebmann, 2007]. Flux computation from high frequency raw data was performed with the Eddy-Pro® software (v. 7.0.6). After removing physically unrealistic flux values from the time series, subsequent post-processing steps such as estimating the u*-threshold, gap-filling and flux partitioning were performed according to Wutzler et al. [2018] with the REddyProc package. Full details of site instrumentation, metadata information and R-packages used for processing can be found in the supplementary material. Since January 2019 the site is approved as an ICOS ecosystem class 1 station (DE-HoH). ICOS standard procedures required an additional EC-setup consisting of a Gill HS-50 ultrasonic anemometer (Gill Instruments Ltd., Lymington, Hampshire, UK) and a LI-7200 gas analyser which runs in parallel to the above described system (see ICOS carbon portal: https://www.icos-cp.eu/data-products/ecosystem-release)
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