Golgi apparatus (glow scale) and microtubules (green) in a typical mammalian cell.
Active biomembranes not only constitute the envelope of eukaryotic cells but also structure the cell's interior via compartmentalization into organelles. On all biomembranes, lipids and proteins are acting in concert to fulfill specific duties, e.g., to trigger signaling cascades and to form transport vesicles. These processes often consume chemical energy (hence the term “active” biomembranes) and they are crucial for the viability of the cell, i.e., malfunctions are related to severe diseases like cancer.
Working at the interface of physics and biology, our mission is a quantitative understanding of active biomembranes. Due to its paradigmatic character, we have chosen the membrane traffic in the early secretory pathway (i.e. between the endoplasmic reticulum, ER, and the Golgi apparatus) as our favorite biological model system. While the local arrangement of lipids and proteins in this context is on nanometer and (sub-)microsecond scale, the formation of membrane domains and transport carriers (vesicles and tubules) is on the scale of several micrometers and minutes. The biogenesis of an organelle like the Golgi apparatus due to ER-derived membrane traffic happens on even larger scales. Thus, understanding membrane traffic along the early secretory pathway employs at least four orders of magnitude in space (1nm-10ìm) and ten orders of magnitude in time (100ns-100s) and is thus a Multi-scale problem in the length and time domain.
To approach the challenging questions associated with membrane traffic in eukaryotic cells, the group not only employs theoretical approaches but we also make use of advanced fluorescence microscopy techniques, e.g. fluorescence recovery after photobleaching (FRAP) and fluorescence correlation spectroscopy (FCS). With these techniques one can determine kinetic and diffusional parameters in living cells.
For further details please also have a look at open PhD projects and our publication list.