Previous and current research
Our group is interested in the molecular mechanisms of endocytosis, an essential
function of all eukaryotic cells. We focus on 1) the mechanisms of endosome biogenesis,
2) how endocytic transport regulates and, in turn, is regulated by signalling
molecules and 3) the regulation of endocytosis in polarised cells. Much of our
progress originated from work on the small GTPase Rab5. By directing a network
of over 30 effectors, Rab5 integrates various functions in vesicle formation,
tethering and fusion, microtubule-dependent motility of early endosomes and signal
transduction. Based on the analysis of Rab5, we have formulated a model whereby
Rab-GTPases organize a mosaic of intercommunicating membrane domains, Rab-domains,
providing functional identity to cellular organelles
Future prospects and goals
We aim at a comprehensive understanding of endosome function with respect to
organelle biogenesis, signal transduction and cell polarity, capitalizing on
our progress on the Rab machinery and further extending the molecular analysis
to novel regulatory components. Our aims are the following:
1. A major focus of our group is the study of endosome dynamics in living cells.
We rely on fast live cell imaging techniques with subsequent analysis and quantification
using a software package developed in our group. Such combination of high-end
imaging and advanced image analysis methodologies offers a unique entry point
into fundamental aspects of membrane trafficking. Current projects include the
study of cargo- and machinery dynamics during endosomal transport, endosome movement
along cytoskeletal tracks and continuous refinement of our image analysis algorithms.
2. A further challenge is the cognitive analysis of high-throughput genome-wide
RNA interference screens to identify novel regulatory components of the endocytosis
and signalling machinery. We have developed algorithms for quantifying compartment
morphology, subcellular distribution and colocalization in the large image sets
resulting from high-throughput screens. These tools will provide a basis for
the development and implementation of new algorithms allowing supervised and
non-supervised quantitative phenotype definition. Reconstructing regulatory networks
and developing a systems biology approach to endocytosis (collaboration with
Prof. A. Deutsch, TU-Dresden) provide another challenging task for scientists
with a background in physics or computer sciences.
3. Cell polarity: we have been pursuing the identification and functional characterization
of novel molecules regulating endocytic transport in C. elegans, D. melanogaster,
zebrafish and mice).
4. We have discovered a novel specialized endosome devoted to signalling (see
figure). We are currently investigating the role of this new compartment during
development.
Selected publications
Miaczynska, M., Christoforidis, S., Giner, A., Shevchenko, A., Uttenweiler-Joseph, S., Habermann, B., Wilm, M., Parton, R.G., and Zerial, M. (2004): APPL Proteins Link Rab5 to Nuclear Signal Transduction via an Endosomal Compartment. Cell 116, 445-456.
Hoepfner, S., Severin, F., Cabezas, A., Habermann, B., Runge, A., Gillooly, D., Stenmark, H., and Zerial, M. (2005): Modulation of receptor recycling and degradation by the endosomal kinesin KIF16B. Cell 121, 437-50.
Pelkmans, L., Fava, E., Grabner, H., Hannus, M., Habermann, B., Krausz, E., and Zerial, M. (2005): Genome-wide analysis of human kinases in clathrin- and caveolae/raft-mediated endocytosis. Nature 436, 78-86.
Pelkmans, L., and Zerial, M. (2005): Kinase-regulated quantal assemblies and kiss-and-run recycling of caveolae. Nature 436, 128-33.
Rink, J., Ghigo, E., Kalaidzidis, Y., and Zerial, M. (2005): Rab conversion as a mechanism of progression from early to late endosomes. Cell 122, 735-49.
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Marino Zerial
1982: Ph.D. in Biology, University of Trieste, Italy
1983-1985: Postdoctoral Fellow, Institute J. Monod, Paris
1985-1988: Postdoctoral Fellow, EMBL, Heidelberg
1989-1991: Staff Scientist, EMBL, Heidelberg
1991-1997: Research Group Leader at Cell Biology Programme EMBL, Heidelberg
since 1998: Director, Max Planck Institute of Molecular Cell Biology and Genetics, Dresden
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