Physics of sensing and shaping membranes in living cells

Living cells need to exert tight control over their lipid membranes to maintain their internal structure, to guard their outside boundary, to establish potential and concentration gradients as their energy source, or to transmit signals between their compartments and to the outside. As a consequence, elaborate molecular machineries have evolved that allow cells to sense and regulate both shapes and physical characteristics of their lipid membranes. The molecular modeling of these machineries faces significant challenges because of their complexity, size, and dynamic nature. To address these challenges, we combine atomistic and coarse-grained simulations of protein-membrane systems. In my talk, I will examine mechanisms used by eukaryotic cells to sense the physical state of their membranes, and to create their intricately shaped membrane structures. Remarkably, physical aspects of the membranes emerge as key factors: fluctuation characteristics and first-order-like transitions in shape space.