Biology and Geography

Medical Biology Research

The Structural and Medical Biochemistry ­research group successfully concluded its work on the design of a protein-based MRI contrast agent. The group also studied the interaction of the domains of the mitotic regulator Pin1, which is a key regulator of the cell cycle and is involved in protein quality control and microtubuli formation. The group is also working on the orth­ologous proteins from the parasites Trypanosoma brucei and Leishmania major and has commenced research on the toxicity and therapeutic efficacy of antimicrobial peptides as a promising alter­native to conventional antibiotics.

In cooperation with experimental research scientists, the Bioinformatics group (Prof. Daniel Hoffmann) studies biological systems over a wide range of spatial and temporal scales, with evolution as the underlying link between them. ­Recent results include the identification of gen­etic markers in Chinese variants of HIV (with Prof. Rongge Yang, Wuhan Institute of Virology), the detection of new ways in which Hepatitis C virus evades the immune system (with Prof. Jörg Timm, University Hospital Essen), and the discovery of enzymatic activity in sonic hedgehog, a protein which plays a crucial role in embryonic development (with Prof. Kay Grobe, University of Münster, and the Developmental Biology group of Prof. Andrea Vortkamp).

Prof. Vortkamp’s Developmental Biology group investigates the molecular mechanisms regulating chondrocyte differentiation in endochondral bones during embryonic development and misregulation in degenerative diseases like osteo­arthritis. One current focus of the group’s work is on the role of heparan sulfate as a regulator of extracellular growth factor signalling and the role of transcription factors and epigenetic modifiers in regulating chondrocyte differentiation. Researchers from the group were recently able to reveal the role of the transcription factor Trps1 as a regulator of histone deacetylase activity linking transcriptional activity with epigenetic modification. This work further demonstrated that Trps1-deficient mice have an increased ­histone 3 acetylation level, which leads to defects in cell cycle progression.

The Microbiology research group led by Prof. Michael Ehrmann uses genetic, molecular biology and biochemical methods to elucidate the key mechanisms of protein quality control. The work focuses on the widely conserved HtrA family of serine proteases, consisting of a protease and an additional PDZ domain, the latter functioning as a protein-protein interaction module. Recent work has revealed additional mechanistic information on PDZ proteases. Structural and biochemical studies showed how another protease, CtpB, regulates sporulation in Gram-positive bacteria. Prof. Ehrmann received two distinctions for his outstanding scientific contributions: In 2013, he was elected Fellow of the American Academy of Microbiology and appointed Professorial Research Fellow of Cardiff University, UK, for 2013 and 2014.

The group of Prof. Hemmo Meyer (Molecular Biology I) works on fundamental molecular mechanisms that ensure correct inheritance of the genome during cell division. Errors in this process lead to genomic instability, which in turn is a hallmark of cancer cells. The group has now shown that, if genome damage occurs, a molecular machine called p97 helps to rapidly degrade the cell division factor CDC25A in order to prevent the cell from dividing and propagating chromosome aberrations to the daughter cells. The group also studied the spindle apparatus that segregates the chromosomes during cell ­division. They revealed how the regulatory factor SDS22 modulates protein modification to correct errors in the attachment of the chromosomes to the spindle in order to ensure equal partitioning of the genome to the daughter cells.

The research group headed by Prof. Markus Kaiser in preparative Chemical Biology focuses on the development of novel chemical tools for biomedical basic research, chemical proteomics or as a starting point for chemotherapeutic drug discovery efforts. One focus of the group’s work has been on developing a chemical probe for plant biology applications and identifying and elucidating the underlying molecular mechanisms. These studies have resulted in the identification of the first chemical inhibitor of jasmonate ­signalling, an essential system that controls immunity to pathogens in plants. The chemical probe for this system has opened up new avenues in basic plant science and agricultural research. Together with other groups at the University of Duisburg-Essen, the group has developed structurally novel inhibitors for selected medically relevant enzymes, which make it possible to study the function of these proteins in the onset or progression of disease (e. g. cancer).

The research interests of Prof. Shirley Knauer’s group (Molecular Biology II) focus on trans­lational clinical oncology and cell biology. One aim of their work is to gain a detailed understanding of the regulation of nucleo-cytoplasmic transport, its impact on cellular homeostasis, malignant transformation in cancer development and as a potential target for new therapy strategies. Current projects concentrate on the molecular and pathophysiological functions of the inhibitor of apoptosis and mitotic regulator protein survivin, to which a decisive role is ­attributed in cancer development, and on the oncologically relevant protease Taspase1. Work on gaining a detailed molecular understanding of the effects and therapeutic applications of nanoparticles and their surrounding protein ­corona has become a further central interest in the group. The German Life Science Award of the GBM and Roche was awarded in 2013 in ­recognition of this exemplary interdisciplinary integration of basic and translational biomedical research.

The focus of Prof. Perihan Nalbant’s group is the study of cellular signalling cascades that control the reorganisation of the actin cytoskeleton during dynamic processes. By using modern ­fluorescence microscopy methods in combination with RNAi-based protein manipulation, the group was able to identify a signalling cascade in invasive tumour cells that guarantees the formation of contractile fibres by assembling short actin ­filaments in the protrusive cell front. The group is now studying the spatial and temporal crosstalk of this contractility signalling cascade with other actin regulatory proteins in order to gain a deeper understanding of the molecular basis of complex cell movements.