Mathematical Physics Seminar 23/3 – Dr David Zwicker – Controlling phase separation inside biological cells
Abstract: Biological cells consist of thousands of different biomolecules that move and react rapidly. Yet, cells display robust behavior, partly because they separate molecules into distinct compartments. It is now clear that many small compartments are droplets formed via phase separation, but we do not yet understand how cells control these droplets. In this talk, I will discuss two specific control mechanisms. First, I will introduce a novel method to study phase separation in multicomponent fluids. I will use it to show how cells can adjust molecular interactions over evolutionary time scales to form multiple different types of droplets robustly. Second, I will turn to non-equilibrium systems and demonstrate that driven chemical reactions provide a powerful way to regulate droplets. These reactions influence the physical properties of droplet components and thus their phase behavior. I will show that such active droplets can stably coexist with controlled size and position. These two examples demonstrate how cells can leverage phase separation to control their spatial structure over relevant time scales.