Cellular Distribution Center
In order to allocate the many proteins at the right time to the right place, the cell needs an address and distribution station: The Golgi apparatus. There the proteins are marked and send to the different areas of the cell. Julia von Blume investigates with her group, which molecules and structures are needed for this processes and how mistakes influence them.
After synthesis proteins are brought to the Golgi apparatus. This organelle consists of flat, membrane-bound compartments that are densely stacked on top of each other. Inside of these chambers the proteins are marked with an “address” by adding different signal molecules. Tagged like that they are transported into specific areas of the Golgi itself, carried off into other cell organelles or even transported to the surface or out of the cell.
Calcium is the key
In former studies von Blume already identified actin, a central support and transport molecule, as a key player in these processes. Also the complex ADF/cofilin, which regulates actin, is involved in protein sorting of the Golgi. Julia von Blume’s experiments suggest that these two factors interact in certain areas of the Golgi and recruit the calcium transporter SPCA1. SPCA1 is an important player, which increases the local concentration of calcium ions. If proteins bind to them, they are then enclosed in membrane vesicles and exported to the cell surface.
Beneath the skin
Von Blume would also like to understand, how the rare skin disease Hailey-Hailey evolves. Patients with this illness suffer from discoloration of the skin, itching and blistering. Due to a genetic defect, the calcium transporter SPCA1 does not work correctly. Certain proteins which are crucial for cell-cell adhesion in the epidermis can no longer be discharged from the cell. Julia von Blume wants to understand what impact this defect has on the sorting and transport of proteins.