Cellular Electron Microscopy

Contact: Michael W. Hess, PhD
Associate Professor of Cell Biology
telephone: +43 (0)512 9003 71176
mobile phone: +43 (0)676 4998916
Michael.Hess@i-med.ac.at; Karin Gutleben
Research Technician
telephone: +43 (0)512 9003 71177
Karin.Gutleben@i-med.ac.at

Our cell biological research concentrates on ultrastructural aspects of membrane traffic, in particular on intracellular signalling pathways. We investigate the spatial and temporal regulation of the EGFR-ERK-cascade in model organisms such as mouse and Drosophila by means of cryo-based (immuno-) electron microscopy (high-pressure freezing, freeze-substitution, Tokuyasu-immunolabelling). These studies focus on the role of endosomal compartments as signalling platforms, and are carried out in close collaboration with the group of Prof. Lukas A. Huber (Division of Cell Biology, Innsbruck-Biocenter). Moreover, we perform methodological research on various organisms from all kingdoms aiming at the improvement and development of specimen and labelling procedures as well as of mammalian cell culture systems. State-of-the-art EM-equipment is at our disposal: transmission electron microscopes (PHILIPS CM120, ZEISS EM 10A), high-pressure freezing apparatus (BAL-TEC HPM010), freeze-substitution device (LEICA AFS), ultra-microtomes (LEICA Ultracut S, plus cryosectioning chamber LEICA FCS); field-emission scanning electron microscope (ZEISS DSM 982 Gemini plus Centaurus BSE-detector), freeze-fracture device (BALZERS BA360M), Critical Point Dryer and SEM-coating-device (BAL-TEC CPD030 and MED 020, respectively).

Funding by: FWF-Austrian Science Funds, ÖNB-Austrian National Bank, TWF-Tyrolean Science Funds, MFF- Tyrolean Medical Research Funds, TILAK-Tiroler Landeskrankenanstalten, Innsbruck Medical University.

Selected references

Hess, M. W. (2006). Cryopreparation methodology for plant cell biology. In "Cellular Electron Microscopy" (J. R. McIntosh, Ed.). Methods Cell Biol Vol 79, Academic Press, Elsevier Inc., San Diego, in press.
Hess, M.W., Pfaller, K., Hampolz, B., Longato, S., Teis, D., Florl, A., Gutleben, K., and Huber, L.A. (2006). Microscopy of the Drosophila facet eye: Vademecum for standardized fixation, embedding, and sectioning. Microsc Res Tech 69, 93-98.
Teis, D., Kurzbauer, R., Taub, N., Hilber, D., Erlacher, M., Villunger, A., Geley, S., Bohn, G., Klein, C., Hess, M. W., and Huber, L. A. (2006). The p14/MP1-MEK1-signalling complex links the late endosomal transport of the EGFR with mitogenic ERK signalling. Submitted
Puhakainen, T., Hess, M. W., Makela, P., Svensson, J., Heino, P., and Palva, E. T. (2004). Overexpression of multiple dehydrin genes enhances tolerance to freezing stress in Arabidopsis. Plant Mol Biol 54, 743-53.
Hess, M.W. (2003). Of plants and other pets: practical aspects of freeze-substitution and resin embedding. J Microsc 212, 44-52.
Haller, T., Dietl, P., Pfaller, K., Frick, M., Mair, N., Paulmichl, M., Hess, M.W., Furst, J., and Maly, K. (2001). Fusion pore expansion is a slow, discontinuous, and Ca2+-dependent process regulating secretion from alveolar type II cells. J Cell Biol 155, 279-289.
Hess, M.W., Muller, M., Debbage, P.L., Vetterlein, M., and Pavelka, M. (2000). Cryopreparation provides new insight into the effects of brefeldin A on the structure of the HepG2 Golgi apparatus. J Struct Biol 130, 63-72.
Hess, M.W., Schwendinger, M.G., Eskelinen, E.L., Pfaller, K., Pavelka, M., Dierich, M.P., and Prodinger, W.M. (2000). Tracing uptake of C3dg-conjugated antigen into B cells via complement receptor type 2 (CR2, CD21). Blood 95, 2617-2623.
Poranen, M.M., Daugelavicius, R., Ojala, P.M., Hess, M.W., and Bamford, D.H. (1999). A novel virus-host cell membrane interaction. Membrane voltage-dependent endocytic-like entry of bacteriophage straight phi6 nucleocapsid. J Cell Biol 147, 671-682.