The main focus of our research is the role of the spatiotemporal organization of membrane protein complexes in cellular bioenergetics. On the molecular and physiological level, we aim to understand how the specific ultrastructure and dynamics of mitochondria contribute to an optimal adaptation of the organelle in response to different metabolic requirements and conditions. The functionality of mitochondria under certain demands and also threats is closely associated with ultrastructural and morphological changes of the organelles, but details of the relation are still poorly understood. Thus, a main focus of our studies lies on dissecting the mobility of mitochondrial membrane proteins, the plasticity of the inner mitochondrial membrane and the morpho-dynamic changes of the mitochondrial network governed by fusion and fission dynamics, which together generate mitochondrial heterogeneity in terms of function. In this context, we analyze the association of membrane proteins into macromolecular complexes or supercomplexes as a key element of adaptive function in situ. Part of this research is further to understand the spatiotemporal organization of oxidative phosphorylation (OXPHOS) complexes in mitochondria on the single molecule level.
We study mitochondria in live mammalian cells with diverse advanced microscopic methods. To determine mitochondrial function on the sub-organellar level in situ, we continuously develop and refine fluorescent reporter systems for high and superresolution imaging. For quantitative analysis, programs are adapted in cooperation with the CALMOS and the Biophysics group/Osnabrück. Different transgenic cell lines are used to investigate basic mitochondrial morpho-functional interrelations and the overall significance of organelle and protein dynamics. The spatio-temporal organization of OXPHOS complexes is addressed by dual color superresolution fluorescence and immuno-electron microscopy.
Multi-color Localization Microscopy of Single Membrane Proteins in Organelles of Live Mammalian Cells
1School of Biology, University of Osnabrück,
2Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück,
3Department of Biology, WWU Münster