Eukaryotes achieve their high performance by distributing their various functions on spatially membrane-bound subcellular compartments. By doing so, however, they are challenged by a severe problem: Subcellular structuring abolishes the principle of free intracellular accessibility at the expense of functional gain, as is still the case with prokaryotes. The membranes of all eukaryotic compartments, whether those of the nucleus, mitochondria, peroxisomes or chloroplasts, represent a significant diffusion barrier for the majority of molecules in a cell. Few of these molecules can overcome them, usually only with a high energy input. Compartmentalization or accessibility - an insurmountable contradiction? This is where the research of our group begins.
To address this question, we use quantitative methods of protein biochemistry, cell biology, electrophysiology and single-molecule microscopy and, in collaboration with other research groups, high-resolution cryo-electron microscopy.
Specifically, the following topics are addressed in our department:
Of particular interest is the molecular architecture of the protein translocase of mitochondrial outer membranes, and the question of how proteins are transported by this translocase into mitochondria.
The release of cytotoxic proteins from mitochondria regulated by proteins of the Bcl-2 family is considered a key event of apoptosis. The modification of the Bcl-2 protein BAX with a palmitic acid residue and thus its integration into mitochondrial outer membranes play a crucial role. Based on this observation, we are seeking for new concepts for the control of malignant tumor cells, in which the palmitoylation of BAX is reduced.
As part of the research network Functional Nanostructures of the Baden-Württemberg Foundation, we are developping new technologies for the integration of biological nanopores into supported lipid bilayers to be use for biosensor applications.