Geschlechtsdifferenzierte Genexpression(S. 12)
Sonja Grath, John Parsch
Sexual dimorphism, the difference in morphology, physiology and be - havior between males and females, is a widespread phenomenon. Differential gene expression between the sexes, known as sex-biased gene expression, is a major contributor to sexual dimorphism and has been investigated in many diverse species. Here, we discuss how genes with sex-biased expression are defined and identified, and how understanding their special characteristics is important for various fields of biology, ranging from evolution to medicine.
Grenzgänger – Proteine zwischen Kaliumtransportern und -kanälen(S. 15)
Inga Hänelt , Charlotte Stock, Marina Schrecker, Vedrana Mikusevic
Channels and transporters are traditionally considered as two completely different entities. However, members of the superfamily of potassium transporters question this strict separation. They function as odd ion channels or chimeras of channels and transporters to meet their specific requirements. Recent structural data reveal the molecular basis of their unique functions.
Mit modernen Methoden zu magnetischen Mikroben(S. 18)
Dirk Schüler, Rudolf Amann
Magnets, methods, and microbes have contributed to the study of magnetotactic bacteria over the past decades. On the way from an unlikely discovery to making Magnetospirillum the “Microbe of 2019” there has been a fruitful interaction of classical microbiological methods with emerging molecular techniques. This has turned the view of magnetotactic bacteria from microbial curiosities towards established models for prokaryotic cell biology and biomineralization.
Nanokristalle für die Magnetfeldorientierung – Biogenese von Magnetosomen(S. 22)
Dirk Schüler, René Uebe
Alphaproteobacteria of the genus Magnetospirillum use dedicated organelles, the magnetosomes, to navigate along geomagnetic field lines in their natural environment. Magnetosomes are nanocrystals of magnetite (Fe3O4) which are biomineralized within specific membrane vesicles and become aligned into chains by a dedicated cytoskeleton. This article also highlights the potential for functionalization and application of these bacterial magnetic nanoparticles.
Monitoring von Giftstoffen im Meer(S. 26)
Jennifer S. Strehse, Jennifer Baas, Edmund Maser
The seas worldwide are threatened by a “new” source of pollution: Millions of tonnes of all kind of munition that have been dumped after World War II will corrode and start to leak. As part of a BMBF funded consortium we are establishing an open sea water program to monitor contaminations of the marine ecosphere by using passive samplers and the mussel Mytilus edulis. The data derived will be important to address the safety of the marine ecosphere, marine fishery resources and, finally, the health of human sea food consumers.
Eine oder zwei Membranen bei Prokaryoten: Was war zuerst da?(S. 29)
Jennifer Flechsler, Carolin Pickl, Andreas Klingl
From a classical perspective, the bacterial cell wall is divided into Grampositive and Gram-negative. It was shown recently that several Grampositive bacterial groups (monoderm) might have developed from diderm bacteria by losing the outer membrane. Within the archaea, recent studies also describe diderm cell walls via high-resolution electron microscopy. A rising number of structural information on uncultivated microorganisms sheds new light on potential cell wall architectures of the first living cells.
Probennahme per Laserablation von Krebsgeweben für Proteomics(S. 32)
Hartmut Schlüter, Tobias Lange
Distant metastasis is the major cause of cancer-related death in virtually all tumour types. We used spontaneous metastasis xenograft mouse models to study differences between primary tumours and corresponding metastases at the proteome level. Sampling of tissues for proteomics with mechanical homogenization is critical, because by this process many proteins are getting lost. For improving the protein yield infrared laser ablation was applied for sampling.
Selektive Proteinmarkierung mit Nanometerpräzision in lebenden Zellen(S. 37)
Many dynamic biological processes are regulated by protein-protein interactions and protein localization. Experimental techniques and tools with high precision are required to gain a deeper understanding of biological processes. Microfluidic cell squeezing facilitated the high-throughput labeling of proteins by high-affinity probes and nanobodies. The method combines target-specific tracing of proteins with the fine-tuned delivery of nanomolar concentrations and allows the live-cell super-resolution microscopy.
Das maßgeschneiderte Proteom: Proteinmodifikation durch Proteolyse(S. 41)
Fatih Demir, Andreas Perrar, Pitter Huesgen
Site-specific proteolytic processing is an irreversible post-translational protein modification with essential regulatory functions. Dedicated methods enable proteome-wide characterization of differentially processed proteoforms based on their distinct protease-generated N termini. Exemplary profiling of murine glomeruli revealed processed forms of proteins with important functions in the renal filtration barrier. Altered processing was observed in cellular and animal models of glomerular disease.
Proteomik-Analyse von dynamischen Proteinkomplexen(S. 45)
Stefanie Egetemaier, Julien Béthune
Analytical methods are required to characterize the protein-protein interactions that underlie all biological processes. Beside affinity purification/ mass spectrometry approaches, proximity-dependent labeling techniques rely on the biotinylation of interacting proteins in living cells for their proteomic analysis. We summarize here the principles of these approaches and present a split proximity-dependent labeling assay that allows the analysis of context-dependent protein complexes.
Anwendungen & Produkte
Expression und Untersuchung von Pflanzenproteinen mit Leishmania tarentolae(S. 60)
Elfriede Dall, Andreas Licht, Hans Brandstetter
Glycosylation is an important post-translational modification that can be found in many eukaryotic proteins. Since it can be crucial for protein structure and function, properly glycosylated proteins are of paramount importance for crystal structure determination. The eukaryotic expression system LEXSY, based on the protozoan Leishmania tarentolae, has been used to express and crystallize fully glycosylated Arabidopsis thaliana legumain γ and elucidate the role of glycosylation for its function.
Vereinfachung der routinemäßigen Mykoplasmen-Testung in der Zellkultur(S. 62)
Jürgen Weidner, Burkhard Greve, Wolfgang Göhde, Josef Wischmann
The contamination of cell cultures with Mycoplasma ssp. is unfortunately well known in the scientific community. A good laboratory management is needed to avoid these unwanted contaminations. To provide a reliable tool for routine testing of cell cultures, we would like to introduce a new freeze dried Mycoplasma PCR Detection Kit. Only a few working steps are needed to obtain the results within three hours.
Karriere, Köpfe & Konzepte
Raubtiere und zahnlose Tiger: Publizieren in Zeiten von Predatory Journals(S. 96)
Geht das Vertrauen in die Wissenschaft durch skrupellose, korrupte Raubtierverlage, Fake-Konferenzen und Fake-Publikationen verloren? Betrügen Wissenschaftler systematisch und verpulvern Steuergelder, um ihre Reputation und ihre Eitelkeit aufzuplustern? Die Antwort ist nein – aber es gibt Einschränkungen, und die Probleme, warum es diese Einschränkungen gibt, sind nicht so einfach zu lösen.