Project (Sarah Köster)
Our group focuses on cellular mechanics, in particular the cytoskeleton. We are interested in how the different filament types (actin filaments, microtubules, intermediate filaments) assemble and disassemble, how their intrinsic interactions (within and between filaments) lead to distinct mechanical behavior and how this influences cell function. Importantly, we use a variety of biophysical tools (imaging: optical microscopy, x-rays; scattering: x-rays; manipulation and force measurements: optical tweezers, atomic force microscopy) in combination with cell and protein biology and biochemistry and quantitative data analysis.
We have open position in different fields available:
(A) Interactions between synaptic vesicles and the cytoskeleton: We have developed a novel combination of microfluidics and single molecular fluorescence spectroscopy, with which we are able to measure the interaction of biological molecules and assemblies. In this project we will use this method, along with TIRF microscopy and high-resolution imaging methods (confocal, STED, expansion microscopy) to shed light on the interplay between synaptic vesicles and cytoskeletal protein filaments as it takes place in the synapse. We will use an in vitro setting and try to answer questions like “does the synaptic vesicle cluster organize the actin cytoskeleton around it or vice versa?”
(B) X-ray imaging of biological cells: X-rays provide a great complementary probe for imaging small structures in biological cells. We are now at a point where we can combine x-ray imaging with other, complementary methods, such as light microscopy. This project will develop these novel methods further. This includes work at synchrotron radiation sources (e.g., DESY in Hamburg or ESRF in Grenoble), design and building of new instrumentation, measurements on relevant biological systems (cell lines, primary, cells, tissues or biofilms) and innovative data analysis. The aim is to combine information from x-ray measurements with data from light microscopy.
(C) Mechanics of cytoskeletal filaments: The cytoskeleton is a versatile “composite” network of biopolymers. Depending on their share in this network, their interactions and the structures formed, the cell can mechanically adapt to situations as different as, e.g., migration, contraction or division. We have a number of in vitro and cellular approaches in place to quantitatively study these aspects and aim to answer questions like “do the filaments directly interact and if so, which forces are involved?”; “Which role do cross-linking agents play?”; “Which dynamics do we observe when molecular motors are involved?”
Homepage Research Group
https://www.uni-goettingen.de/koesterlab
Publications:
Laura Schaedel*, Charlotta Lorenz*, Anna V. Schepers, Stefan Klumpp, and Sarah Köster (*equal contribution): Vimentin intermediate filaments stabilize dynamic microtubules by direct interactions, Nature Communications (2021), 12, 3799, DOI: 10.1038/s41467-021-23523-z
Andrew Wittmeier, Chiara Cassini, Mareike Töpperwien, Manuela Denz, Johannes Hagemann, Markus Osterhoff, Tim Salditt, and Sarah Köster: Combined Scanning Small Angle X-Ray Scattering and Holography Probes Multiple Length Scales in Cell Nuclei, Journal of Synchrotron Radiation (2021), 28, DOI: 10.1107/S1600577520016276
Charlotta Lorenz, Johanna Forsting, Anna V. Schepers, Julia Kraxner, Susanne Bauch, Hannes Witt, Stefan Klumpp, Sarah Köster: Lateral Subunit Coupling Determines Intermediate Filament Mechanics, Physical Review Letters (2019), 123, 188102, DOI:10.1103/PhysRevLett.123.188102
Eleonora Perego and Sarah Köster: Exploring early time points of vimentin assembly inflow by fluorescence fluctuation spectroscopy, Lab on a Chip (2021), 21, 735 - 745, DOI: 10.1039/D0LC00985G