University of Würzburg

About: University of Würzburg is a education organization based out in Wurzburg, Bayern, Germany. It is known for research contribution in the topics: Population & Gene. The organization has 31437 authors who have published 62203 publications receiving 2337033 citations. The organization is also known as: Julius-Maximilians-Universität Würzburg & Würzburg University.

From research to action: Enhancing crop yield through wild pollinators

Abstract: Recent evidence highlights the value of wild-insect species richness and abundance for crop pollination worldwide. Yet, deliberate physical importation of single species (eg European honey bees) into crop fields for pollination remains the mainstream management approach, and implementation of practices to enhance crop yield (production per area) through wild insects is only just beginning. With few exceptions, studies measuring the impacts of pollinator-supporting practices on wild-insect richness and pollination service success – particularly in relation to long-term crop yield and economic profit – are rare. Here, we provide a general framework and examples of approaches for enhancing pollinator richness and abundance, quantity and quality of pollen on stigmas, crop yield, and farmers' profit, including some benefits detected only through long-term monitoring. We argue for integrating the promotion of wild-insect species richness with single-species management to benefit farmers and society.

Bcl-2 interacting protein, BAG-1, binds to and activates the kinase Raf-1

Abstract: The Bcl-2 protein blocks programmed cell death (apoptosis) through an unknown mechanism. Previously we identified a Bcl-2 interacting protein BAG-1 that enhances the anti-apoptotic effects of Bcl-2. Like BAG-1, the serine/threonine protein kinase Raf-1 also can functionally cooperate with Bcl-2 in suppressing apoptosis. Here we show that Raf-1 and BAG-1 specifically interact in vitro and in yeast two-hybrid assays. Raf-1 and BAG-1 can also be coimmunoprecipitated from mammalian cells and from insect cells infected with recombinant baculoviruses encoding these proteins. Furthermore, bacterially-produced BAG-1 protein can increase the kinase activity of Raf-1 in vitro. BAG-1 also activates this mammalian kinase in yeast. These observations suggest that the Bcl-2 binding protein BAG-1 joins Ras and 14-3-3 proteins as potential activators of the kinase Raf-1.

Expression of the cathelicidin LL-37 is modulated by short chain fatty acids in colonocytes: relevance of signalling pathways.

Abstract: Background and aims: Short chain fatty acids (SCFA) exert profound effects on the colonic mucosa. In particular, SCFA modulate mucosal immune functions. The antimicrobial cathelicidin LL-37 is expressed by colon epithelial cells. In the present study the effect of SCFA on LL-37 expression was investigated. Methods: LL-37 expression in vivo was assessed by immunohistochemistry. Real time quantitative reverse transcription-polymerase chain reaction was employed to determine LL-37 expression in colonocytes in vitro after treatment with various cytokines, SCFA, or flavone. LL-37 levels were correlated to cell differentiation which was determined by alkaline phosphatase (AP) activity. In addition, intracellular signalling pathways such as MEK-ERK (mitogen/extracellular signal protein kinase (MEK)/extracellular signal regulated protein kinase (ERK)) and p38/mitogen activated protein (MAP) kinase were explored. Results: In vivo, LL-37 expression in healthy mucosa was restricted to differentiated epithelial cells in human colon and ileum. In colonocytes, increased LL-37 expression associated with cell differentiation was detected in vitro following treatment with butyrate, isobutyrate, propionate, and trichostatin A. Flavone induced LL-37 transcription but did not affect AP activity while cytokines had no effect. To dissect pathways mediating differentiation and LL-37 expression, specific inhibitors were applied. Inhibition of the protein kinase MEK enhanced butyrate induced AP activity while LL-37 expression in colon epithelial cells was blocked. In contrast, inhibition of p38/MAP kinase blocked cell differentiation without inhibiting LL-37 expression. Conclusions: Expression of the cathelicidin LL-37 in colonocytes and cellular differentiation are separately modulated by SCFA via distinct signalling pathways. These data may provide a rationale for dietary modulation of mucosal defence mechanisms.

Photoproduction of Proton Gradients with π-Stacked Fluorophore Scaffolds in Lipid Bilayers

Abstract: Rigid p-octiphenyl rods were used to create helical tetrameric pi-stacks of blue, red-fluorescent naphthalene diimides that can span lipid bilayer membranes. In lipid vesicles containing quinone as electron acceptors and surrounded by ethylenediaminetetraacetic acid as hole acceptors, transmembrane proton gradients arose through quinone reduction upon excitation with visible light. Quantitative ultrafast and relatively long-lived charge separation was confirmed as the origin of photosynthetic activity by femtosecond fluorescence and transient absorption spectroscopy. Supramolecular self-organization was essential in that photoactivity was lost upon rod shortening (from p-octiphenyl to biphenyl) and chromophore expansion (from naphthalene diimide to perylene diimide). Ligand intercalation transformed the photoactive scaffolds into ion channels.