Berlin 2018 – scientific programme

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BP: Fachverband Biologische Physik

BP 9: Postersession I

BP 9.15: Poster

Monday, March 12, 2018, 17:30–19:30, Poster A

Organelle-specific density measurements of the V-ATPase using atomic force microscopy — Elisabeth Eilers², •Julia Teckentrup^1,2, Katharina Schiller², Volker Walhorn¹, Thorsten Seidel², Karl-Josef Dietz², and Dario Anselmetti¹ — ¹Experimental Biophysics and Applied Nanoscience, Bielefeld University, Germany — ²Plant Biochemistry and Physiology, Bielefeld University, Germany

The V-ATPase functions as a membrane-embedded rotational proton pump, which creates a proton motif force and thus drives secondary active transport of solutes across endomembranes. Therefore, these enzymes are essential for cellular pH- and ion homeostasis.

V-ATPases are located in the endomembranes of the endoplasmic reticulum, the Golgi apparatus as well as the vacuolar membrane in plants, which we could show using molecular biology techniques and fluorescence microscopy. In atomic force microscopy (AFM) images, V-ATPases showed prominent structures with a height of roughly 10 nm corresponding to the hexameric arrangement of their catalytic head. Using AFM we aim to investigate the differences in the number of V-ATPases between different compartments of plant cells. We will further apply AFM-based single molecule force spectroscopy to test the stability of the complexes. The latter is driven by the observation, that the vacuolar enzyme shows a diffuse organization of its stabilizing stalk proteins in the presence of desoxyglucose as observed by FRET-microscopy (Schnitzer et al., 2011, Plant Cell Physiol.).