BMP-Signaltransduktion – begleitet von control freaks und gate keepers(S. 686)
Gina Dörpholz, Patrizia Weigell, Petra Knaus
Bone morphogenetic proteins (BMPs) are crucial growth factors from embryonic development up to adult organ/tissue homeostasis since they regulate versatile processes such as stem cell maintenance, differentiation and migration. Aberrant signalling leads to pathologies including cancer or musculoskeletal and vascular diseases. Here, we provide an overview of the BMP signalling cascade and its complex regulation and show how we investigate this tightly controlled protein network in physiological and pathological model systems.
Zellwandkanäle von Corynebacteriales(S. 691)
In addition to a thick peptidoglycan layer, the cell wall of Corynebacteriales contains mycolic acids covalently linked to arabinogalactan. The mycolic acids are organized with extractable lipids in a permeability barrier. The cell wall of different families of Corynebacteriales contains channels responsible for its permeability. These channels have a structure completely different from porins of Gram-negative bacteria. Their structures depend on the length of the mycolic acids of the corresponding genera.
BAG3-vermittelte selektive Makroautophagie bei Proteinstress und Alterung(S. 695)
Selectivity of macroautophagy is provided by ubiquitin receptors, adaptors and auxiliary proteins allowing specific targeting of degradation substrates. The co-chaperone BAG3 (Bcl-2-associated athanogene 3) mediates degradation of aggregation-prone proteins in concert with Hsp70. BAG3-mediated selective macroautophagy is an adaptive mechanism to maintain proteostasis during aging and cellular stress and may ultimately provide flexibility and functional stability, especially for post-mitotic cells as neurons.
Faltung und Einbau von Außenmembranproteinen in Lipidmembranen(S. 700)
Lisa Gerlach, Nicole Schürmann, Jörg H. Kleinschmidt
β-barrel transmembrane proteins are present in outer membranes of bacteria and organelles of eukaryotic cells like mitochondria and chloroplasts. After their synthesis in the cytosol, bacterial outer membrane proteins are translocated in unfolded form across the cytoplasmic membrane into the periplasm. Chaperones assist their transport to the β-barrel assembly machinery BAM of the outer membrane. Biophysical studies on outer membrane protein A indicated a concerted folding and insertion mechanism into lipid bilayers for which the activation energy is lowered by the BAM-complex.
Neue seitenspezifische Proteinfunktionalität mit einem Klick(S. 704)
Christine Köhler, Edward A. Lemke
Genetic encoding of custom designed non-canonical amino acids has emerged as one of the most versatile tools to install site-specific “click-reactive” functionalities into proteins. These non-toxic groups can readily react with suitable substances carrying a compatible clickchemistry. The technology can be used for a variety of applications, such as fluorescent labelling of protein in cells to visualize molecular machines and to custom-engineer better drugs.
Neue Einblicke in die Welt isolierter Mikroben(S. 708)
Andreas Schmid, Christian Dusny
Single cell analysis is one of the key technologies for the investigation of cellular functionality. The physical laws at the microscale can be exploited with microfluidic bioreactors for decoupling a cell from the population bias and for cultivating and analyzing it in controllable artificial micro - environments. This gives direct access to the cellular physiology of the minimal unit of life, the single cell.
Komponenten-aufgelöste Diagnostik der Hymenopterengiftallergie(S. 713)
Anke Gräßel, Maximilian Schiener, Stefanie Etzold, Dennis Rußkamp, Simon Blank
Anaphylaxis due to stings of honeybees and wasps is one of the most severe IgE-mediated hypersensitivity reactions. In the last years, increasing knowledge about the venom composition on a molecular level and the availability of recombinant allergens with advanced characteristics, have facilitated the development of component-resolved diagnostics. Here we will give examples for the advantages of such an approach over classical diagnostics and for potential therapeutic implications.
Steroidsulfatierung – von Sexualhormonen und neuen Krebsmedikamenten(S. 717)
Hendrik Reuper, Jonathan Wolf Mueller
In healthy human physiology, several steroid hormones are regulated in a dynamic equilibrium between sulfation and desulfation reactions. Inhibitors of steroid desulfation may soon enter clinical practice in cancer treatment. Sulfation pathways also include sulfate activation and transfer. Targeting the enzymes involved here may be another pharmacological strategy to boost sulfation pathways.
Automatische Bildanalyse für Histologie und Immunhistochemie(S. 720)
Roland Schwarzer, Hannah Sperber, Katharina Paulick
The automated analysis of biological images is improving the quality of image-based studies. Manifold image analysis software is available. However, the vast majority of biological image quantification in diagnosis and research is performed manually. Using automated analysis, results are delivered instantly once a project is setup. The application of this technique will speed up image quantification scans more than 90 percent and objective results can be obtained for scientific users and diagnostic laboratories.
Anwendungen & Produkte
Yeast three-hybrid-Targetidentifizierung per Klick-Chemie(S. 734)
Stefano Rizzo, Rene Lang, Jacqueline Franke, Miriam Bittner
The yeast three-hybrid (Y3H) technology shows substantial potential for the identification of small molecule-target interactions in vivo. However, despite its manifold advantages as a molecular target identification method, the Y3H technique has not yet been widely used, mainly due to the challenges of synthesis of the chemical inducers of dimerization (CIDs) which are essential for this approach. Using the familiar click-technology that is able to connect molecules in an efficient and economical way, Y3H approaches can be developed into a popular target screening technology.
Welche Eigenschaften von Nanopartikeln bestimmen deren Aufnahme in Zellen?(S. 762)
Tobias Schunck, Helen Onyema, Oliver Zupke, Dr. Musyanovych
Even minor discrepancies in the physicochemical properties of nanoparticles (NP) contribute significantly to their interaction with the living cells. The effect of polymer type and surface coating on cellular uptake of polylactide (PLLA) and polystyrene (PS) NP was studied in C6 from rat and human U251 MG cell lines. In C6 cells, NP covered with anionic surfactant show better uptake compared to NP covered with Tween 80. In human cells, the presence of Tween 80 enhances the uptake of PLLA NP, but inhibits the internalization of PS ones.
Lichtgetriebene Ganzzellbiotransformation mit rekombinanten Cyanobakterien(S. 765)
Marc Nowacyk, Robert Kourist
Photosynthetic microorganisms have received considerable attention as production organisms for chemicals. An investigation of the photosynthetic NADPH supply for enantioselective biotransformations with recombinant cyanobacteria showed that the specific activity of the cells is comparable to heterotrophic organisms. Light-dispersion of the cells, however, limits the approach. A wide use as production organisms requires an improvement of several magnitudes.