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Auflistung Publikationen im Open Access gefördert durch die UB nach Auflistung nach DDC "ddc:570"
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Item A Complex Network of Sigma Factors and sRNA StsR Regulates Stress Responses in R. sphaeroides(2021) Eisenhardt, Katrin M. H.; Remes, Bernhardt; Grützner, Julian; Spanka, Daniel-Timon; Jäger, Andreas; Klug, GabrieleItem A dominant clonal lineage of Streptococcus uberis in cattle in Germany(2022) Fenske, Linda; Noll, Irene; Blom, Jochen; Ewers, Christa; Semmler, Torsten; Fawzy, Ahmad; Eisenberg, TobiasItem A major checkpoint for protein expression in Rhodobacter sphaeroides during heat stress response occurs at the level of translation(2021) McIntosh, Matthew; Köchling, Thorsten; Latz, Anna; Kretz, Jonas; Heinen, Sandra; Konzer, Anne; Klug, GabrieleItem A new lipoxygenase from the agaric fungus Agrocybe aegerita: Biochemical characterization and kinetic properties(2019) Karrer, Dominik; Rühl, MartinOxylipins are metabolites with a variety of biological functions. However, the biosynthetic pathway is widely unknown. It is considered that the first step is the oxygenation of polyunsaturated fatty acids like linoleic acid. Therefore, a lipoxygenase (LOX) from the edible basidiomycete Agrocybe aegerita was investigated. The AaeLOX4 was heterologously expressed in E. coli and purified via affinity chromatography and gel filtration. Biochemical properties and kinetic parameters of the purified AaeLOX4 were determined with linoleic acid and linolenic acid as substrates. The obtained Km, vmax and kcat values for linoleic acid were 295.5 μM, 16.5 μM · min⁻¹ · mg⁻¹ and 103.9 s⁻¹ , respectively. For linolenic acid Km, vmax and kcat values of 634.2 μM, 19.5 μM · min⁻¹ · mg⁻¹ and 18.3 s⁻¹ were calculated. Maximum activities were observed at pH 7.5 and 25 ˚C. The main product of linoleic acid conversion was identified with normal-phase HPLC. This analysis revealed an explicit production of 13-hydroperoxy-9,11-octadecadienoic acid (13-HPOD). The experimental regio specificity is underpinned by the amino acid residues W384, F450, R594 and V635 considered relevant for regio specificity in LOX. In conclusion, HPLC-analysis and alignments revealed that Aae-LOX4 is a 13-LOX.Item A protocol for laser microdissection (LMD) followed by transcriptome analysis of plant reproductive tissue in phylogenetically distant angiosperms(2019) Kivivirta, Kimmo; Herbert, Denise; Lange, Matthias; Beuerlein, Knut; Altmüller, Janine; Becker, AnnetteItem A revision of the extant species of Theodoxus (Gastropoda, Neritidae) in Asia, with the description of three new species(2020) Sands, Arthur Francis; Glöer, Peter; Gürlek, Mustafa E.; Albrecht, Christian; Neubauer, ThomasItem A Shift in Perspective: A Role for the Type I Toxin TisB as Persistence-Stabilizing Factor(2022) Edelmann, Daniel; Berghoff, Bork A.Item A Single Residue within the MCR-1 Protein Confers Anticipatory Resilience(2023) Frantz, Renate; Gwozdzinski, Konrad; Gisch, Nicolas; Doijad, Swapnil Prakash; Hudel, Martina; Wille, Maria; Abu Mraheil, Mobarak; Schwudke, Dominik; Imirzalioglu, Can; Falgenhauer, Linda; Ehrmann, Michael; Chakraborty, TrinadThe envelope stress response (ESR) of Gram-negative enteric bacteria senses fluctuations in nutrient availability and environmental changes to avert damage and promote survival. It has a protective role toward antimicrobials, but direct interactions between ESR components and antibiotic resistance genes have not been demonstrated. Here, we report interactions between a central regulator of ESR viz., the twocomponent signal transduction system CpxRA (conjugative pilus expression), and the recently described mobile colistin resistance protein (MCR-1). Purified MCR-1 is specifically cleaved within its highly conserved periplasmic bridge element, which links its Nterminal transmembrane domain with the C-terminal active-site periplasmic domain, by the CpxRA-regulated serine endoprotease DegP. Recombinant strains harboring cleavage site mutations in MCR-1 are either protease resistant or degradation susceptible, with widely differing consequences for colistin resistance. Transfer of the gene encoding a degradation-susceptible mutant to strains that lack either DegP or its regulator CpxRA restores expression and colistin resistance. MCR-1 production in Escherichia coli imposes growth restriction in strains lacking either DegP or CpxRA, effects that are reversed by transactive expression of DegP. Excipient allosteric activation of the DegP protease specifically inhibits growth of isolates carrying mcr-1 plasmids. As CpxRA directly senses acidification, growth of strains at moderately low pH dramatically increases both MCR-1-dependent phosphoethanolamine (PEA) modification of lipid A and colistin resistance levels. Strains expressing MCR-1 are also more resistant to antimicrobial peptides and bile acids. Thus, a single residue external to its active site induces ESR activity to confer resilience in MCR-1-expressing strains to commonly encountered environmental stimuli, such as changes in acidity and antimicrobial peptides. Targeted activation of the nonessential protease DegP can lead to the elimination of transferable colistin resistance in Gram-negative bacteria.Item A succinate/SUCNR1-brush cell defense program in the tracheal epithelium(2023) Perniss, Alexander; Boonen, Brett; Tonack, Sarah; Thiel, Moritz; Poharkar, Krupali; Alnouri, Mohamad Wessam; Keshavarz, Maryam; Papadakis, Tamara; Wiegand, Silke; Pfeil, Uwe; Richter, Katrin; Althaus, Mike; Oberwinkler, Johannes; Schütz, Burkhard; Boehm, Ulrich; Offermanns, Stefan; Leinders-Zufall, Trese; Zufall, Frank; Kummer, WolfgangHost-derived succinate accumulates in the airways during bacterial infection. Here, we show that luminal succinate activates murine tracheal brush (tuft) cells through a signaling cascade involving the succinate receptor 1 (SUCNR1), phospholipase Cβ2, and the cation channel transient receptor potential channel subfamily M member 5 (TRPM5). Stimulated brush cells then trigger a long-range Ca2+ wave spreading radially over the tracheal epithelium through a sequential signaling process. First, brush cells release acetylcholine, which excites nearby cells via muscarinic acetylcholine receptors. From there, the Ca2+ wave propagates through gap junction signaling, reaching also distant ciliated and secretory cells. These effector cells translate activation into enhanced ciliary activity and Cl− secretion, which are synergistic in boosting mucociliary clearance, the major innate defense mechanism of the airways. Our data establish tracheal brush cells as a central hub in triggering a global epithelial defense program in response to a danger-associated metabolite.Item A systematic comparison of chloroplast genome assembly tools(2020) Freudenthal, Jan A.; Pfaff, Simon; Terhoeven, Niklas; Korte, Arthur; Ankenbrand, Markus Johannes; Förster, FrankItem Adaptation of the Alphaproteobacterium Rhodobacter sphaeroidesto stationary phase(2019) McIntosh, Matthew; Eisenhardt, Katrin; Remes, Bernhard; Konzer, Anne; Klug, GabrieleItem Adaptation to Photooxidative Stress: Common and Special Strategies of the Alphaproteobacteria Rhodobacter sphaeroides and Rhodobacter capsulatus(2020) Licht, Mathieu; Nuß, Aaron Mischa; Volk, Marcel; Konzer, Anne; Beckstette, Michael; Berghoff, Bork Ansgar; Klug, GabrieleItem Against the Flow: The Colonisation of the Lesotho Highlands by Freshwater Limpets(2022) Sands, Arthur F.; Riedel, Frank; Gummersbach, Venise S.; Albrecht, ChristianItem Agro-Fruit-Forest Systems Based on Argan Tree in Morocco: A Review of Recent Results(2022) Chakhchar, Abdelghani; Ben Salah, Imane; El Kharrassi, Youssef; Filali-Maltouf, Abdelkarim; El Modafar, Cherkaoui; Lamaoui, MounaItem Annual movements of a migratory seabird - the NW European red-throated diver (Gavia stellata) - reveals high individual repeatability but low migratory connectivity(2022) Kleinschmidt, Birgit; Burger, Claudia; Bustamante, Paco; Dorsch, Monika; Heinänen, Stefan; Morkunas, Julius; Žydelis, Ramunas; Nehls, Georg; Quillfeldt, PetraIn this study, the annual movements of a seabird species, the red-throated diver (Gavia stellata), were investigated in space and time. Between 2015 and 2017, 33 individuals were fitted with satellite transmitters at the German Bight (eastern North Sea). In addition, stable isotope analyses of feathers (δ13C) were used to identify staging areas during the previous moult. The German Bight is an important area for this species, but is also strongly affected by anthropogenic impacts. To understand how this might affect populations, we aimed to determine the degree of connectivity and site fidelity, and the extent to which seasonal migrations vary among different breeding locations in the high Arctic. Tagged individuals migrated to Greenland (n = 2), Svalbard (n = 2), Norway (n = 4) and northern Russia (n = 25). Although individuals from a shared breeding region (northern Russia) largely moved along the same route, individuals dispersed to different, separate areas during the non-breeding phase. Kernel density estimates also overlapped only partially, indicating low connectivity. The timing of breeding was correlated with the breeding longitude, with 40 days later arrival at the easternmost than westernmost breeding sites. Repeatability analyses between years revealed a generally high individual site fidelity with respect to spring staging, breeding and moulting sites. In summary, low connectivity and the distribution to different sites suggests some resilience to population decline among subpopulations. However, it should be noted that the majority of individuals breeding in northern Russia migrated along a similar route and that disturbance in areas visited along this route could have a greater impact on this population. In turn, individual site fidelity could indicate low adaptability to environmental changes and could lead to potential carry-over effects. Annual migration data indicate that conservation planning must consider all sites used by such mobile species.Item The Antarctic Circumpolar Current as a diversification trigger for deep-sea octocorals(2016) Dueñas, Luisa F.; Tracey, Dianne M.; Crawford, Andrew J.; Wilke, Thomas; Alderslade, Phil; Sánchez, Juan A.Background: Antarctica is surrounded by the Antarctic Circumpolar Current (ACC), the largest and strongest current in the world. Despite its potential importance for shaping biogeographical patterns, the distribution and connectivity of deep-sea populations across the ACC remain poorly understood. In this study we conducted the first assessment of phylogeographical patterns in deep-sea octocorals in the South Pacific and Southern Ocean, specifically a group of closely related bottlebrush octocorals (Primnoidae: Tokoprymno and Thourella), as a test case to study the effect of the ACC on the population structure of brooding species. We assessed the degree to which the ACC constitutes a barrier to gene flow between northern and southern populations and whether the onset of diversification of these corals coincides with the origin of the ACC (Oligocene-Miocene boundary). Results: Based on DNA sequences of two nuclear genes from 80 individuals and a combination of phylogeographic model-testing approaches we found a phylogenetic break corresponding to the spatial occurrence of the ACC. We also found significant genetic structure among our four regional populations. However, we uncovered shared haplotypes among certain population pairs, suggesting long-distance, asymmetrical migration. Our divergence time analyses indicated that the separation of amphi-ACC populations took place during the Middle Miocene around 12.6 million years ago, i.e., after the formation of the ACC. Conclusion: We suggest that the ACC constitutes a semi-permeable barrier to these deep-sea octocorals capable of separating and structuring populations, while allowing short periods of gene flow. The fluctuations in latitudinal positioning of the ACC during the Miocene likely contributed to the diversification of these octocorals. Additionally, we provide evidence that the populations from each of our four sampling regions could actually constitute different species.Item Antimicrobial Peptides from Rat-Tailed Maggots of the Drone Fly Eristalis tenax Show Potent Activity against Multidrug-Resistant Gram-Negative Bacteria(2020) Hirsch, Rolf; Wiesner, Jochen; Bauer, Armin; Marker, Alexander; Vogel, Heiko; Hammann, Peter E.; Vilcinskas, AndreasItem Aphid gel saliva : Sheath structure, protein composition and secretory dependence on stylet-tip milieu(2012) Will, Torsten; Steckbauer, Kathrin; Hardt, Martin; van Bel, Aart J. E.In order to separate and analyze saliva types secreted during stylet propagation and feeding, aphids were fed on artificial diets. Gel saliva was deposited as chains of droplets onto Parafilm membranes covering the diets into which watery saliva was secreted. Saliva compounds collected from the diet fluid were separated by SDS-PAGE, while non-soluble gel saliva deposits were processed in a novel manner prior to protein separation by SDS-PAGE. Soluble (watery saliva) and non-soluble (gel saliva) protein fractions were significantly different. To test the effect of the stylet milieu on saliva secretion, aphids were fed on various diets. Hardening of gel saliva is strongly oxygen-dependent, probably owing to formation of sulfide bridges by oxidation of sulphydryl groups. Surface texture of gel saliva deposits is less pronounced under low-oxygen conditions and disappears in dithiothreitol containing diet. Using diets mimicking sieve-element sap and cell-wall fluid respectively showed that the soluble protein fraction was almost exclusively secreted in sieve elements while non-soluble fraction was preferentially secreted at cell wall conditions. This indicates that aphids are able to adapt salivary secretion in dependence of the stylet milieu.Item Artenschwund trotz Naturschutz(2019) Gemeinholzer, Birgit; Demant, Laura; Dieterich, Martin; Eser, Uta; Farwig, Nina; Geske, Christian; Feldhaar, Heike; Lauterbach, Daniel; Reis, Michael; Weisser, Wolfgang; Werk, KlausItem ASA3P: An automatic and scalable pipeline for the assembly, annotation and higher-level analysis of closely related bacterial isolates(2020) Schwengers, Oliver; Hoek, Andreas; Fritzenwanker, Moritz; Falgenhauer, Linda; Hain, Torsten; Chakraborty, Trinad; Goesmann, Alexander