161 research outputs found

    Eukaryotic translation elongation factor 1A (eEF1A) domain I from S. cerevisiae is required but not sufficient for inter-species complementation

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    Ethanolamine phosphoglycerol (EPG) is a protein modification attached exclusively to eukaryotic elongation factor 1A (eEF1A). In mammals and plants, EPG is linked to conserved glutamate residues located in eEF1A domains II and III, whereas in the unicellular eukaryote Trypanosoma brucei, only domain III is modified by a single EPG. A biosynthetic precursor of EPG and structural requirements for EPG attachment to T. brucei eEF1A have been reported, but nothing is known about the EPG modifying enzyme(s). By expressing human eEF1A in T. brucei, we now show that EPG attachment to eEF1A is evolutionarily conserved between T. brucei and Homo sapiens. In contrast, S. cerevisiae eEF1A, which has been shown to lack EPG is not modified in T. brucei. Furthermore, we show that eEF1A cannot functionally complement across species when using T. brucei and S. cerevisiae as model organisms. However, functional complementation in yeast can be obtained using eEF1A chimera containing domains II or III from other species. In contrast, yeast domain I is strictly required for functional complementation in S. cerevisia

    Seed-produced anti-globulin VHH-Fc antibodies retrieve globulin precursors in the insoluble fraction and modulate the Arabidopsis thaliana seed subcellular morphology

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    Key message Nanobody-heavy chain (VHH-Fc) antibody formats have the potential to immunomodulate even highly accumulating proteins and provide a valuable tool to experimentally modulate the subcellular distribution of seed storage proteins. Recombinant antibodies often obtain high accumulation levels in plants, and thus, besides being the actual end-product, antibodies targeting endogenous host proteins can be used to interfere with the localization and functioning of their corresponding antigens. Here, we compared the effect of a seed-expressed nanobody-heavy chain (VHH-Fc) antibody against the highly abundant Arabidopsis thaliana globulin seed storage protein cruciferin with that of a VHH-Fc antibody without endogenous target. Both antibodies reached high accumulation levels of around 10% of total soluble protein, but strikingly, another significant part was present in the insoluble protein fraction and was recovered only after extraction under denaturing conditions. In seeds containing the anti-cruciferin antibodies but not the antibody without endogenous target, the amount of soluble, processed globulin subunits was severely reduced and a major part of the cruciferin molecules was found as precursor in the insoluble fraction. Moreover, in these seeds, aberrant vacuolar phenotypes were observed that were different from the effects caused by the depletion of globulins in knock-out seeds. Remarkably, the seeds with strongly reduced globulin amounts are fully viable and germinate with frequencies similar to wild type, illustrating how flexible seeds can retrieve amino acids from the stored proteins to start germination

    Kommunikation, Konsens und Kohäsion im universitären Kontext

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    Gesellschaftlicher Zusammenhalt wird in Bildungseinrichtungen (Eckert 2007) als Teil eines individuellen, aber gesellschaftlich verantworteten Sozialisationsprozesses in den entsprechenden Lebensphasen (Abels et al. 2008) erfahren. Dafür sind Kommunikationsprozesse von Bedeutung, die entweder selbst zu einem Konsens führen oder in denen die Entstehung eines Konsenses nachvollzogen werden kann. In den kommunikativen Aushandlungsprozessen während eines Studiums werden Wissensbestände diskutiert und Wissensstrukturen aufgebaut. Studierende, aber auch Lehrende erleben so einen Lehr-Lernzusammenhang, der bestenfalls die Genese wissenschaftlichen Wissens verdeutlicht, und erkennen, dass gesättigtes wissenschaftliches Wissen vom Konsens der Beteiligten abhängig ist. Konsens führt damit zu einem geteilten Wissensbestand, der über den konkreten Lehrkontext hinaus Geltung hat und zu sozialer Kohäsion innerhalb der Universitätsgemeinschaft, darüber hinaus in der Scientific Community und in der Gesellschaft an sich führen kann. Dieser fragile Zusammenhang zwischen Kommunikation, Konsens und Kohäsion in der Wissenschaft ist abhängig von verfügbarem Wissen und damit von der Informationsbeschaffung. Veränderungen, wie sie während der Pandemie zu beobachten waren, als Bibliotheksbestände nurmehr digital zugänglich waren und alle Lehr- und Forschungsanstrengungen in die digitale Welt verlegt wurden (Breitenbach 2021), wirken sich deshalb direkt und indirekt auf die Kommunikation der Universitätsgemeinschaft (Mayrberger 2020; Morselli et al. 2021) aus. Deshalb muss die Frage gestellt werden, wie sich das wissenschaftliche, gesellschaftlich geteilte Wissen verändert und welche Auswirkung es haben kann, wenn nurmehr digitale Bestände und Medien genutzt werden können

    Oligo targeting for profiling drug resistance mutations in the parasitic trypanosomatids

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    Trypanosomatids cause the neglected tropical diseases, sleeping sickness, Chagas disease and the leishmaniases. Studies on these lethal parasites would be further facilitated by new and improved genetic technologies. Scalable precision editing methods, for example, could be used to improve our understanding of potential mutations associated with drug resistance, a current priority given that several new anti-trypanosomal drugs, with known targets, are currently in clinical development. We report the development of a simple oligo targeting method for rapid and precise editing of priority drug targets in otherwise wild type trypanosomatids. In Trypanosoma brucei, approx. 50-b single-stranded oligodeoxynucleotides were optimal, multiple base edits could be incorporated, and editing efficiency was substantially increased when mismatch repair was suppressed. Resistance-associated edits were introduced in T. brucei cyclin dependent kinase 12 (CRK12, L(482)F) or cleavage and polyadenylation specificity factor 3 (N(232)H), in the Trypanosoma cruzi proteasome β5 subunit (G(208)S), or in Leishmania donovani CRK12 (G(572)D). We further implemented oligo targeting for site saturation mutagenesis, targeting codon G(492) in T. brucei CRK12. This approach, combined with amplicon sequencing for codon variant scoring, revealed fourteen resistance conferring G(492) edits encoding six distinct amino acids. The outputs confirm on-target drug activity, reveal a variety of resistance-associated mutations, and facilitate rapid assessment of potential impacts on drug efficacy

    Communication Skills in Foreign Languages in Engineering

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    This article is devoted to innovative methods of teaching ESL. The factors of development of engineering activities are shown and the prerequisites for the component composition of a foreign language professional communicative competence are identified. The first positions in achieving the effectiveness of business communication are the verbal activities of the engineer

    A signal motif retains Arabidopsis ER-α-mannosidase I in the cis-Golgi and prevents enhanced glycoprotein ERAD

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    The Arabidopsis ER-α-mannosidase I (MNS3) generates an oligomannosidic N-glycan structure that is characteristically found on ER-resident glycoproteins. The enzyme itself has so far not been detected in the ER. Here, we provide evidence that in plants MNS3 exclusively resides in the Golgi apparatus at steady-state. Notably, MNS3 remains on dispersed punctate structures when subjected to different approaches that commonly result in the relocation of Golgi enzymes to the ER. Responsible for this rare behavior is a novel amino acid signal motif (LPYS) within the cytoplasmic tail of MNS3 that acts as a specific Golgi retention signal. This retention is a means to spatially separate MNS3 from ER-localized mannose trimming steps that generate the glycan signal required for flagging terminally misfolded glycoproteins for ERAD. The physiological importance of the very specific MNS3 localization is demonstrated here by means of a structurally impaired variant of the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1

    Symbiont-host interactome mapping reveals effector-targeted modulation of hormone networks and activation of growth promotion

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    Plants have benefited from interactions with symbionts for coping with challenging environments since the colonisation of land. The mechanisms of symbiont-mediated beneficial effects and similarities and differences to pathogen strategies are mostly unknown. Here, we use 106 (effector-) proteins, secreted by the symbiont Serendipita indica (Si) to modulate host physiology, to map interactions with Arabidopsis thaliana host proteins. Using integrative network analysis, we show significant convergence on target-proteins shared with pathogens and exclusive targeting of Arabidopsis proteins in the phytohormone signalling network. Functional in planta screening and phenotyping of Si effectors and interacting proteins reveals previously unknown hormone functions of Arabidopsis proteins and direct beneficial activities mediated by effectors in Arabidopsis. Thus, symbionts and pathogens target a shared molecular microbe-host interface. At the same time Si effectors specifically target the plant hormone network and constitute a powerful resource for elucidating the signalling network function and boosting plant productivity

    Resistance to the impact of interruptions during multitasking by healthy adults and dysexecutive patients

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    Two experiments (one with healthy adult volunteers and the other with controls and dysexecutive patients) assessed the impact of interruptions on a novel test of multitasking. The test involved switching repeatedly between four tasks (block construction, bead threading, paper folding, alphabetical searching) over a 10 minute period. In Experiment 1, there were 4 groups of 20 healthy participants. One group attempted multitasking with no interruption, a second group was interrupted early in the test, a third group late in the test and a fourth group was interrupted both early and late. Interruption involved carrying out a fifth, unexpected task for a period of one minute before returning to the four main tasks. There was no difference in multitasking performance between the groups. In Experiment 2 the participants were seven dysexecutive patients and 14 age-matched controls. A repeated measures approach was employed to assess the impact of two interruptions (early and late) for both groups. Contrary to predictions, the patients as well as controls were resistant to the effects of interruptions, despite their clearly impaired multitasking performance. These results suggest that the ability to deal with interruptions may be separable from the ability to organise and execute multiple tasks within a limited time frame
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