Panta rhei an der Plasmamembran: Phosphoinositlipide in der Endozytose(S. 607)
Michael Krauss, Volker Haucke
Phosphoinositides (PIs) serve as signposts for membrane traffic and cell signalling. Clathrin-mediated endocytosis from the cell surface is initiated by phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. The following maturation of endocytic structures and their progression towards the endosomal system is accompanied by the generation of phosphatidylinositol-3,4- bisphosphate [PI(3,4)P2] and the dephosphorylation of PI(4,5)P2. Here we summarize the mechanism of PI conversion and its implications for human disease.
Der Beitrag von Mikroorganismen zur Bodenfruchtbarkeit(S. 611)
Anja Miltner, Matthias Kästner
Soil organic matter (SOM) is essential for soil fertility and ecosystem services. Recent results show that easily degradable plant material is degraded by microbes with conversion to CO2 and microbial biomass. Turnover studies with 13C-labelled microbial biomass in soils showed that around 50 percent of the bulk carbon of microbial biomass is stabilized in SOM. Instead of modified plant material microbial necromass after cell death is thus a major constituent of SOM. This has an important impact on the understanding of global soil processes.
Thermophile Archaea – RNA im Kochtopf(S. 615)
Michael Daume, Lennart Randau
Hyperthermophilic archaea need to adapt to their permanently hot habitats. RNA-Seq analyses were applied to obtain insights into small RNA synthesis, maturation, and stability at extreme growth temperatures. Modifications, including methylation and circularization, are used to stabilize RNA molecules. Antiviral measures are abundant in hyper - thermophilic archaea which might include the frequently occurring fragmentation of tRNA genes.
Quantitatives Imaging durch molekulare Auflösung(S. 618)
Sebastian Van de Linde, Markus Sauer, Nadine ehmann, Robert J. Kittel
Among all powerful super-resolution fluorescence imaging methods single-molecule localization microscopy excels as it delivers virtually molecular resolution and thus direct information about the distribution of molecules in cells. When efficient labelling is ensured it can be even used to estimate absolute numbers of molecules. Thus, this microscopy method has the potential to provide fascinating insights into how bio - logical functions, such as neuronal plasticity, memory, and behaviour are encoded at the molecular level.
Dynamik nativer mRNA am Beispiel der Balbiani-Ring-mRNPs(S. 622)
Jan-Peter Siebrasse, Ulrich Kubitscheck
The transport of messenger RNA-protein particles (mRNPs) has been studied by numerous experimental approaches with quite controverse results. Only a close look into experimental details and recent single molecule experiments using the Balbiani ring mRNPs of the salivary gland cells of Chironomus tentans allowed to resolve the contradictory data. Intranuclear mRNP transport requires some ten seconds, and thus is not rate-limiting for gene expression, since transcription and translation take minutes up to hours for very long genes.
Das Y-Chromosom als forensischer und genealogischer Marker(S. 627)
Lutz Roewer, Maria Geppert, Josephine Purps, Sascha Willuweit
DNA markers on the human Y chromosome are used as an investigative tool in crime labs all over the world. Especially in sexual assault cases the Y chromosome provides essential evidence. Because male relatives share for several generations an identical Y chromosome profile and paternal relatives tend to live in the geographic and cultural territory of their ancestors, the Y chromosome analysis can also infer the probable geographic origin of an unknown male DNA.
Digitale Polymerasekettenreaktion (dPCR)(S. 632)
Patrick Gürtler, Lars Gerdes
Real-time PCR used to be the gold standard when it comes to detection of rare mutations, copy number variations or genetically modified organisms. A new option for DNA analyses is the digital PCR. In digital PCR, the reaction mix is distributed to many partitions and endpoint PCR is performed. The fraction of positive partitions can be used to calculate the initial concentration. Digital PCR is highly sensitive and allows quantification of absolute copy numbers without using a standard curve.
Molekulare Analyse aminerger Signalwege im ZNS der Taufliege(S. 636)
Christine Fink, Stella Schukies, Jakob von frieling, Thomas Roeder
Biogenic amines such as dopamine and octopamine (the invertebrate counterpart of epinephrine) are highly relevant to control numerous behaviours. In humans, deregulation of these signalling systems is associated with various neurological disorders. To understand the underlying molecular and cellular processes, we combine comprehensive analysis of transcriptomic events in different cell populations of the dopaminergic and octopaminergic signalling systems with tailored manipulation of these cell populations using the fruit fly Drosophila as a model system.
Anwendungen & Produkte
ExoIN-Technologie – ein schneller Weg zu stabilen Assay-Zelllinien(S. 648)
Bettina Baumann, Doetmar Lenz
Clonal cell lines stably expressing a target protein are a common tool in research, but the generation of such cell lines is laborious and time-consuming. In contrast, the novel ExoIN technology guarantees easy-to-handle and fast cell line generation. By expressing selection marker and target as a polyprotein that is efficiently cleaved at the ribosome, unmodified free protein is homogeneously expressed in all cells of the stable cell population.
Bacillus megaterium – ein Produktionssystem für rekombinante Proteine(S. 650)
Arne Schulz, Maren Fräger, Linda Holtkamp, Jörg Ronnenberg, Rebekka Bidendieck
During the past years plasmid systems for recombinant protein production using Bacillus megaterium were developed. These systems are based on multicopy plasmids with functional elements for cloning in Escherichia coli and induced gene expression in B. megaterium. Different promoters, signals for protein secretion and affinity tags for purification arranged in a high variety of combinations are available. By using these systems, recombinant proteins can be produced and secreted in the grams per litre scale.
Effiziente Detektion und Differenzierung von Norovirus-RNA(S. 652)
Ute Hofmann, Melanie Kelm, Awad Osman, Alexander Berka
To provide an efficient routine sample testing norovirus detection methods must meet a number of important criteria. Due to the seasonal varying sample loads and beside sufficient sensitivity and specificity the amendment to high throughput modifications is of particular importance.
Koordinatenbestimmung von Proteinpunkten in 2D-PAGE-Gelen(S. 655)
Marina Hanneken, Doreen Ackermann, Simone König
A major problem in two-dimensional protein gel electrophoresis is the little comparability of gel images. A reference grid of marker proteins in parallel to the separation of the analyte by use of two fluorescent dyes allows the correction of protein coordinates. The deviation from mean is improved by an order of magnitude. The technology called comparative 2D fluorescence gel electrophoresis (CoFGE) can be carried out in both vertical and horizontal electrophoresis instrumentation.
Corynebacterium glutamicum als Produzent von Pyruvat-abgeleiteten Produkten(S. 694)
Bastian Blombach, Bernhard Eikmanns
Pyruvate as a key metabolite of the central metabolism in bacteria is also a precursor for several biotechnologically relevant compounds. Therefore, efforts have been made to tailor the metabolism of the industrially relevant Corynebacterium glutamicum for optimal pyruvate availability and an optimal flux towards pyruvate-derived products. Here we summarize the recent achievements on metabolic engineering of C. glutamicum for production of pyruvate, L-valine, 2-ketoisovalerate and isobutanol.