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dc.contributor.advisor Janshoff, Andreas Prof. Dr.
dc.contributor.author Brückner, Bastian Rouven
dc.date.accessioned 2017-04-12T08:06:28Z
dc.date.available 2017-04-12T08:06:28Z
dc.date.issued 2017-04-12
dc.identifier.uri http://hdl.handle.net/11858/00-1735-0000-0023-3E12-7
dc.language.iso eng de
dc.relation.uri http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject.ddc 571.4 de
dc.title Membrane tension homeostasis of mammalian cells de
dc.title.alternative -mechanosensitive study of the area regulation of adherent cells de
dc.type doctoralThesis de
dc.contributor.referee Janshoff, Andreas Prof. Dr.
dc.date.examination 2016-06-03
dc.description.abstracteng Although a cell is the smallest unit that is viable on its own, its construction and processes are of great complexity. Many functions, which keep a cell alive, are only poorly understood up to now. Plasma membrane tension is supposed to be a key player in controlling a variety of cellular functions, such as cell migration, division or apoptosis. In order to investigate how membrane tension is controlled by enlargement or reduction of excess surface area, polarised epithelial cell monolayers were studied. Madin-Darby canine kidney cells (MDCK II) serve as a cellular model system to unravel the question how tension-driven membrane surface area regulation is realised to accommodate tension changes. The mechanical behaviour of cells was measured by force-indentation experiments followed by membrane tether extraction. These experiments carried out by atomic force microscopy (AFM) in conjunction with the application of a powerful mechanical model, the tension model, provide a deep insight into the interplay between tension control and excess surface area regulation. The performance of the tension model in reproducing the mechanical behaviour of plasma membranes was investigated. In order to provoke tremendous changes in the mechanical behaviour of cells, the role of the cytoskeleton for tension homeostasis was unravelled. Since the membrane-cytoskeleton attachment dominates membrane tension, the importance of the linker molecule ezrin was studied by ezrin depletion. Cells stabilise each other in a confluent monolayer by forming tight connections to neighbouring cells. Tight junctions mediated by zonula occludens-1 and adherens junctions built up by E-cadherins are important cell-cell connections in MDCK II cells. The role of both proteins for tension homeostasis was clarified by experiments disrupting one or the other connection. Furthermore, the role of endocytosis, a process driven by membrane surface area changes and cytoskeleton rearrangement, was investigated in terms of tension and membrane surface area adjustment. In summary, this study allows us to draw a comprehensive picture of membrane tension homeostasis by surface area regulation. Our data demonstrate the importance of an intact cytoskeleton and an intact membrane-cytoskeleton interface for tension maintenance. Alterations of the cellular morphology of the cell monolayer do not necessarily provoke an altered mechanical behaviour of the cells, as long as the cytoskeleton is unaffected and a stable contact to binding partners is maintained. de
dc.contributor.coReferee Köster, Sarah Prof. Dr.
dc.subject.eng Atomic Force Microscopy de
dc.subject.eng Cell Mechanics de
dc.subject.eng Tension Homeostasis de
dc.subject.eng Cell Membrane de
dc.subject.eng Epithelial Cells de
dc.identifier.urn urn:nbn:de:gbv:7-11858/00-1735-0000-0023-3E12-7-8
dc.affiliation.institute Göttinger Graduiertenschule für Neurowissenschaften, Biophysik und molekulare Biowissenschaften (GGNB) de
dc.subject.gokfull Biologie (PPN619462639) de
dc.identifier.ppn 884472582

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