Advances in Biosciences Seminar: Dr Darius Koester, University of Warwick - "Using minimal systems to study mechanisms governing cell membrane organisation"
| Dates: | 21 May 2024 |
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| Times: | 13:00 - 14:00 |
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| What is it: | Seminar |
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| Organiser: | Faculty of Biology, Medicine and Health |
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| Who is it for: | University staff |
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| Speaker: | Darius Koester |
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Abstract: Cells in our body and in other organisms are constantly exposed to mechanical signals from their environment. The cell plasma membrane and its underlying actin cytoskeleton are the primary receiver of these signals and act as a processing platform for signalling as well as the uptake and release of cargo, to name a few processes. My research interest lies in the understanding of the molecular and physical principles that govern these processes at the plasma membrane. Particularly, by which mechanisms the force generating machinery of the cell cortex, structural filaments, and motor proteins, govern and regulate the mechanical properties of the cell membrane and dynamics of cell membrane components, and vice versa, how membrane organisation and signalling events feed-back to the regulation of the cortex machinery. These mechanisms, which in turn regulate cell motility and cell-cell interactions, underlie important, poorly understood human diseases that constitute global health problems.
Here, we use reconstituted minimal systems of the membrane – cortex interface to dissect and understand the interlinked contributions of cytoskeletal activity and membrane organisation. We use quantitative imaging approaches, controlled mechanical and biochemical manipulations and work with theoretical physicists to understand how cells might use the active cell cortex to generate local and temporal order in the plasma membrane. In a second part, I will present how studying cells adhering to functionalised lipid bilayers can offer new insights into the cell cortex dynamics during E-cadherin mediated cell-cell adhesion.
Bio: Darius Koester is an Associate Professor in the Centre for Mechanochemcial Cell Biology at the University of Warwick working on questions concerning cell surface mechanics. After studying Physics at University of Leipzig, he joined 2007 the groups of Patricia Bassereau (Physics) and Christophe Lamaze (Biology) at Institut Curie (Paris) for a PhD supervised by Pierre Nassoy. He employed optical tweezers to measure cell membrane tension in combination with micro-mechanical, biochemical, and genetic manipulations to decipher the role of Caveolae, cell membrane invaginations, as a buffer for cell membrane tension, protecting the cell plasma membrane from rupture.
This was followed in 2011 by a postdoc with Satyajit (Jitu) Mayor at the National Centre for Biological Sciences (Bangalore). Here, he designed and did set up a minimal system of acto-myosin networks connected to supported lipid bilayers to study the effect of the active, remodelling actin network on the dynamics and clustering of membrane proteins. He could show that this minimal system constitutes an active composite system displaying increased membrane molecule clustering and dynamics, which corroborated a novel theoretical model developed by Madan Rao to understand protein clustering in the cell plasma membrane.
In 2017, he moved to Warwick University to work with Mohan Balasubramanian on the reconstitution of the cytokinetic ring machinery and started his own group in 2018 as an assistant professor in the Centre for Mechanochemical Cell Biology. His group develops methods to study active membrane systems in 2D and 3D combined with mechanical manipulation and aims to expand to more complex lipid and membrane proteins mixtures to understand the role of cortex-membrane interactions in membrane tension and mechano-signalling.
Speaker
Darius Koester
Role: Associate Professor
Organisation: University of Warwick
Travel and Contact Information
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Michael Smith Lecture Theatre
Michael Smith Building
Manchester
