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BP: Fachverband Biologische Physik
BP 1: Membranes, Vesicles, Synthetic Cells
BP 1.2: Talk
Monday, March 27, 2023, 09:45–10:00, BAR Schö
Surface-induced phase separation of reconstituted nascent integrin clusters — •Chiao-Peng Hsu1, Jonas Aretz2, Reinhard Fässler2, and Andreas Bausch1 — 1Center for Functional Protein Assemblies and Lehrstuhl für Zellbiophysik (E27), Physics Department, Technische Universität München, Garching, Germany — 2Max Planck Institute of Biochemistry, Martinsried, Germany
Integrin adhesion complexes are essential membrane-associated cellular compartments for multi-cellular life. While biomolecular condensates organize specific functions in cells, cell membranes can regulate the positions and dynamics of many biomolecular condensates. Yet, the role played by membrane surfaces in the formation of initial integrin adhesion complexes still needs to be fully understood. Here, we report that phosphoinositides containing lipid membranes induce minimal integrin adhesion condensates composed of integrin β tails, kindlin, talin, paxillin, and FAK at physiological ionic strengths and protein concentrations. We show that the presence of phosphoinositides is key to enriching kindlin and talin on the membrane, forming first nascent integrin complexes, which in turn are necessary to further nucleate condensates. These results demonstrate that the biophysical properties of lipid membranes are key for inducing specific membrane-associated condensates throughout the cell.