TY  - GEN
ID  - heidok12658
Y1  - 2011///
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/12658/
N2  - In the first part of this thesis, we study the diffusive motion of the (un)folded transmembrane protein VSVG in the endoplasmic reticulum (ER). Unfolded VSVG interacts with the ER?s quality control machinery. These interactions are probed by Fluorescence Correlation Spectroscopy in vivo. We find that both, folded and unfolded VSVG show anomalous diffusion, however, the unfolded protein has a significantly stronger anomaly. Our experimental data and accompanying simulations suggest that parts of the quality control oligomerize unfolded VSVG, leading to a more anomalous/obstructed diffusion. The difference in anomaly subsides when unfolded VSVG is in a complex with its chaperone calnexin. Hence, calnexin dissolves the oligomers and thus prevents ER poisoning. The second part of this work is dedicated to the influence of cell?s shape on its internal organization. We find that organelle positions show large variations in ensembles of equally shaped cells, hence challenging the idea of a ?standard cell?. However, depending on cell geometry and symmetry, the centrosome shows a preferential direction of displacement from the cell center. Simulations that include pushing forces of microtubules on the centrosome and the repulsion of the nucleus by the cell membrane explain this localization.
TI  - On the spatial organization of cell organelles and diffusion of proteins in organelle membranes
A1  - Malchus, Nina Isabelle
AV  - public
KW  - Zellorganisationanomalous diffusion 
KW  -  membrane proteins 
KW  -  cell organization
ER  -