Molecular biology

  • Bacterial Pac Man molecule snaps at sugar

    The P domain (yellow) patrols with its mouth open until it encounters a sialic acid molecule (purple). This movement was analyzed with distance measurements using the spin markers shown in blue.  © Dr. Gregor Hagelüken/Uni Bonn

    Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

  • Chemists Create Clusters of Organelles by Mimicking Nature

    Two polymersomes assemble by DNA hybridization: the single DNA strands on the surface of the compartments interconnect, creating an extremely stable DNA bridge. University of Basel

    Scientists from the University of Basel have succeeded in organizing spherical compartments into clusters mimicking the way natural organelles would create complex structures. They managed to connect the synthetic compartments by creating bridges made of DNA between them. This represents an important step towards the realization of so-called molecular factories. The journal Nano Letters has published their results.

  • Cholesterol important for signal transmission in cells

    CXCR4 receptor which belongs to a group known as G protein-coupled receptors. FAU/Rainer Böckmann

    Cholesterol can bind important molecules into pairs, enabling human cells to react to external signals. Researchers at Friedrich-Alexander University Erlangen-Nürnberg’s (FAU) Chair of Biotechnology have studied these processes in more detail using computer simulations. Their findings have now been published in the latest volume of the journal PLOS Computational Biology*. FAU researchers Kristyna Pluhackova and Stefan Gahbauer discovered that cholesterol strongly influences signal transmission in the body. Their study focused on the chemokine receptor CXCR4, which belong to a group known as G protein-coupled receptors (GPCRs). These receptors sense external stimuli such as light, hormones or sugar and pass these signals on to the interior of the cell which reacts to them. CXCR4 normally supports the human immune system. However, it also plays an important role in the formation of metastases and the penetration of HIV into the cell interior.

  • Genregulation: In Form für den richtigen Schnitt

    Bindung der großen Untereinheit von U2AF an die Vorläufer-Boten-mRNA Bild: Christoph Hohmann / NIM

    Bevor genetische Information in Proteine umgesetzt wird, entfernt eine komplexe molekulare Maschine – das Spleißosom – nicht benötigte Sequenzen. Dabei spielt dessen Struktur eine wichtige Rolle, wie LMU-Wissenschaftler zeigen. Ribonukleinsäure – kurz RNA – übermittelt die in den Genen gespeicherten Erbinformationen und damit die Bauanleitung für Proteine. Bei der Genabschrift im Zellkern entsteht zuerst eine Vorläufer-Boten RNA (mRNA), aus der durch eine komplexe molekulare Maschine im Zellkern – das Spleißosom –unterschiedliche nicht benötigte Abschnitte herausgeschnitten und entfernt werden. Dieser Vorgang wird als alternatives Spleißen bezeichnet und spielt für die Genregulation eine wichtige Rolle, denn jeder der zurechtgeschnittenen mRNA-Stränge liefert den Bauplan für ein anderes Protein – ein Gen kann also in mehrere Proteine mit unterschiedlicher Funktion umgesetzt werden.

  • Immune system reactions elucidated by mathematics

    Bacteria of the species Streptococcus pneumoniae colonising an endothelial cell. HZI/M. Rohde

    Using computer-based simulations and mouse experiments, HZI researchers disentangled the effects of proinflammatory signaling molecules on the post-influenza susceptibility to pneumococcal coinfection. A body infected by the influenza virus is particularly susceptible to other pathogens. Bacteria like Streptococcus pneumoniae, i.e. the pathogen causing pneumonia, find it easy to attack an influenza-modulated immune system and to spread widely. This can even be fatal in some cases. The reasons for the bacterial growth in the presence of a coinfection by influenza virus and bacteria is still debatable.

  • Molecules change shape when wet

    The preferred structure of a crown ether changes when water molecules bind to it (dashed lines). © C. Pérez et al.

    Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water. In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max Planck Institute for the Structure and Dynamics of Matter at CFEL and from the Hamburg Centre for Ultrafast Imaging (CUI) show that water promotes the reshaping of crown ethers and biphenyl molecules, two classes of chemically fascinating molecules. Crown ethers are key systems in catalysis, separation and encapsulation processes, while biphenyl-based systems are employed in asymmetric synthesis and drug design.

  • New software helps to find out why “jumping genes” are activated

    Transposons - Jumping genes © Nanobay

    Jumping genes, so-called transposons, reproduce as parasites in the genome. This selfish behaviour can be an evolutionary advantage for the organism or harm it. There is still a debate about the factors controlling the activity of transposons. Comparisons between populations could shed an answer on this but have been biased due to technical problems. The software PoPoolationTE2 developed by the Institute of Population Genetics at Vetmeduni Vienna enables an unbiased analysis for the first time and determines the frequency of transposons. This might also be useful for cancer research and neurology. The software was presented in the renowned journals Molecular Biology and Evolution.

  • Novel mechanisms of action discovered for the skin cancer medication Imiquimod

    Dr. Christina J. Groß (links) and Dr. Ritu Mishra.

    Imiquimod is a medication successfully used in the treatment of skin diseases. In addition to its known mechanism of action, it also triggers other processes in the body. Scientists at the Technical University of Munich (TUM) have succeeded in explaining the molecular fundamentals of these additional effects. The results also shine a new light on other known molecular processes which could indicate an approach to the treatment of inflammatory illnesses.

  • Paradigm shift in the research field of photoreceptor transplantation

    See press release.  © CRTD

    Paradigm shift in the research field of photoreceptor transplantation: mechanism improving the function of the retina works different than previously assumed

    The research group of Prof. Dr. Marius Ader, group leader at the DFG-Center for Regenerative Therapies Dresden (CRTD), Cluster of Excellence at TU Dresden, introduces a new understanding of the mechanism of cell transplantations that aim to improve retinal function. Affected retinal degenerative diseases are for example age-related macular degeneration (AMD) and Retinitis Pigmentosa (RP) with a current total of approximately 1.6 million patients affected in Germany.

  • Protein with Multiple Duties

    molecular barrel structure serves various functions in the mitochondria.

    Freiburg researchers demonstrate how a molecular barrel structure serves various functions in the mitochondria

  • Research team at the CRTD identifies cells that form new bone during Axolotl finger regeneration

    Joshua Currie and Elly Tanaka. © CRTD

    At the DFG-Center for Regenerative Therapies Dresden (CRTD) - Cluster of Excellence at the TU Dresden, a team of researchers lead by Joshua Currie, PhD, and Elly Tanaka, PhD, used live imaging during axolotl regeneration to identify the unique migration kinetics of various connective tissue cell types which choreograph their fate and tissue contribution during regeneration. The results were published in the scientific journal Developmental Cell on November 21, 2016.

  • Researchers uncover protein-based “cancer signature”

    Gene expression level of individual ribosomal proteins (RP) in different types of cancer (blue: lower level; red: higher level compared to normal tissue). University of Basel, Biozentrum

    A research team at the University of Basel’s Biozentrum has investigated the expression of ribosomal proteins in a wide range of human tissues including tumors and discovered a cancer type specific signature. As the researchers report in “Genome Biology” this “cancer signature” could potentially be used to predict the progression of the disease. Proteins are the building blocks of life. They are produced by molecular machines, called ribosomes. A human ribosome contains some eighty ribosomal proteins. Prof. Mihaela Zavolan’s research group at the Biozentrum of the University of Basel has now discovered that about a quarter of the ribosomal proteins have tissue-specific expression and that different cancer types have their own individual expression pattern of ribosomal proteins. In the future, these patterns may serve as a prognostic marker for cancer and may point towards new therapeutic opportunities.