SKM 2023 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 11: Poster Session I
BP 11.49: Poster
Dienstag, 28. März 2023, 12:30–15:30, P1
Amplified self-stabilization of cell adhesions under load — •Julia Müllner1,2 and Benedikt Sabass1,2 — 1Institute for Infectious Diseases and Zoonoses, Department of Veterinary Sciences, LMU München — 2Department of Physics, LMU München
Cell adhesion is crucial for the structural organization of living organisms. Experimentally, it was found that planar cell-matrix adhesions respond to an increase in shear force by growing in size in order to maintain structural stability. As part of this process, the protein vinculin binds to force-activated binding sites of talin and to actin, thereby strengthening the cluster. However, it is not fully understood how mechanical forces induce adhesion molecules to drive adhesion growth. We present a minimalist model to explore the dynamics of an adhesion cluster under shear force. The system is reduced to a single adapter molecule species (talin) that can undergo conformational changes when being stretched. As in an open system, molecules are exchanged between a reservoir and the adhesion cluster. To account for adhesion growth upon molecule unfolding, we expand the reservoir rate to be proportional to the number of unfolded molecules. Simulation results show that the number of adhesion bonds rises with increasing shear force, as seen in experiments. A state diagram is constructed, delineating regimes of adhesion stabilization from unbounded growth and adhesion rupture. An analytical mean-field model yields solutions that are in good agreement with the simulation results. Overall, we describe and characterize a mechanism that amplifies self-stabilization of cellular adhesions under load.