Ein neues Signalmolekül in Burkholderia cenocepacia(S. 368)
Leo Eberl, Christian Jenul, Simon Sieber, Karl Gademann
Many social behaviours of bacteria are regulated by quorum sensing through the production and perception of structurally diverse signal molecules. The opportunistic pathogen Burkholderia cenocepacia uses classic N-acyl-homoserinlactones and cis-2-unsatturated fatty acids for communication. A recent study has identified an additional signal, valdiazen, which carries an unusual diazenium diolate group. Genomic information suggests that valdiazen-like compounds constitute a new class of signal molecules.
Das Kiwellinprotein: über die biologische Funktion eines Allergens(S. 372)
Regine Kahmann, Gert Bange, Xiaowei Han, Florian Altegoer
Kiwellin proteins of plants have previously been recognized as important human allergens, however their biological role remained unknown. Here, we discuss recent progress towards an understanding of their role as plant-defense proteins towards pathogenic fungi and beyond.
TALEs – 10 Jahre nach Entschlüsselung des Codes(S. 375)
Jens Boch, Stefanie Mücke
Plant-pathogenic bacteria of the genus Xanthomonas use transcription activator-like effectors (TALEs) to induce gene expression in host plants and promote disease. Deciphering the code of TALE-DNA binding in 2009 was a milestone, which enabled researchers to predict TALE virulence targets and generate resistant plants with modern genome editing tools.
Krieg und Frieden: molekulares Ping- Pong zwischen Pilzen und Pflanzen(S. 378)
Gunther Döhlemann, Katharina Eitzen, Jan Schulze Hüynck, Selma Schurack
The outcome of plant-microbe interactions is determined by the interplay of the microbial virulence repertoire with the plant immune system. We are using the interaction of the biotrophic fungal pathogen Ustilago maydis with its host plant maize as a model system. The fungus secretes effector proteins to modulate host metabolism, development, and immune responses. Functional characterization of these effectors helps us to understand the molecular basis of the complex interactions of plants and microbes.
Neue Einblicke in die Entstehung von komplexen Karyotypen bei Krebs(S. 382)
Zuzana Storchova, Sara Vanessa Bernhard
Cancer cells differ from healthy cells by massively altered genomes. This includes point mutations as well as chromosomal rearrangements and changes in chromosome numbers. Novel in vitro models mimic chromosomal aberrations and allow their systematic analysis. Here we present recent findings how changes in chromosome numbers and their structure alter physiology of human cells and instigate further genomic instability, thus recapitulating the processes that occur during tumorigenesis.
Membranproteinfaltung – Kernwissen aus (nicht zu) vereinfachten Systemen(S. 385)
Alexej Kedrov, Maryna Löwe, Michael Kamel, Athanasios Papadopoulos
Despite their functional and structural diversity, membrane proteins of all living cells are inserted and assembled via a few evolutionary conserved pathways. Here, we describe how studies in model membranes provide insights into the functionality of the Sec translocon, a primary machinery for the insertion of a-helical membrane proteins, but also for translocation of unfolded polypeptide chains across the membrane. To bring together in vitro and in vivo analysis, further developments of new membrane mimetics are suggested.
Lysinacetylierung – eine kleine Modifikation mit großer Wirkung(S. 389)
Michael Lammers, Robert Vogt, Magdalena Kremer, Leona Berndt
Ageing is the main risk factor for the development of cancer, cardiovascular diseases, neurodegenerative and metabolic disorders. It is important to develop strategies to ensure a healthy ageing process. Caloric/dietary restriction is beneficial for an organism’s healthspan and results in changes in cellular lysine acetylation patterns. Therefore, lysine acetylation likely constitutes an important mediator of this intervention. Here we describe recent developments in the research field.
Optogenetischer Werkzeugkasten für neue experimentelle Ansätze(S. 398)
Amelie Bergs, Jana Liewald, Alexander Gottschalk
In rhodopsin-based optogenetics the light-activatable cation channel ChR2 is employed to selectively gain control over single neurons. As arising experimental questions become more and more challenging, there is a strong need to further expand the optogenetic toolbox. Along with the discovery of various natural rhodopsins, molecular engineering facilitates the development of custom tools for a variety of applications, ranging from cell culture to light-control of whole organisms like Caenorhabditis elegans.
Anwendungen & Produkte
Apoptose und Nekrose in Echtzeit messen(S. 412)
Measuring mechanisms and timing of cell death is important to distinguish physiological from pathological cellular events or to find suitable cancer therapies. A microplate assay measures apoptosis based on extracellular phosphatidylserine exposure of apoptotic cells. The specific binding of annexin V to phosphatidylserine is converted to a luminescent signal. In parallel, the assay reports on necrosis by a non-permeable fluorescent DNA dye entering only cells with a disrupted cell membrane.
Semi-automatische Rekonstruktion von Neuronen(S. 414)
Adrian A. Wanner, My-Tien Nguyen, Julia Tran, Marie E. Müller
The vast amount of data that is generated by today’s imaging technologies renders manual annotation and analysis infeasible. Novel workflows combining human and artificial intelligence are able to process terabytesized datasets. A new online neuron reconstruction service for light microscopy data achieves excellent accuracy meeting high scientific standards and reduces the required efforts to trace neurons.
Wurzelkulturen als Produktionssystem(S. 455)
Michael Wink, Bernhard Wetterauer
A number of plant natural products are of commercial interest for pharmacy, medicine, agriculture, or nutrition. A challenge for biotechnology is the production of such compounds in vitro. Whereas callus and suspension cultures of plants mostly fail as production systems, differentiated root cultures provide a better platform. We established normal and transformed root cultures of Ophiorrhiza mungos, which produce the anticancer drug camptothecin in yields, which are similar to differentiated plants.
Eutektische Lösungsmittel in der Biokatalyse(S. 458)
Dirk Holtmann, Magdalena Pätzold
Perfect solvents in biocatalysis have to fulfill a large number of requirements, such as high enzyme activity and stability, and high substrate solubility. Deep eutectic solvents (DES) have recently been evaluated as new solvents in different biocatalytic reactions. They can provide improvements in substrate supply, conversion and stability. The best results were obtained when the DES is formed by the substrates of an enzymatic reaction.