Taylor Schaffner

Many post-translational modification networks take place in the fluid yet structured plasma membrane. Lipid domains, sometimes termed rafts, have been implicated in the functioning of various membrane-bound signaling processes. In the first part of my talk, I present a model and a Monte Carlo simulation framework to investigate how changes in the domain size that arise from perturbations to the membrane phase transition can lead to changes in the rate of interactions among components, leading to altered outcomes. For simple reaction networks, I show that the activity can be highly sensitive to the thermodynamic parameters of the membrane phase transition, especially near the critical point. Experimental measurements of two otherwise dissimilar systems, zebrafish cells and yeast vacuoles, exhibit near constant gaps between growth temperature and membrane miscibility temperature, hinting at a potentially fundamental regulatory mechanism. In the second part of my talk, I will demonstrate how the sensitivity of interaction rates among membrane-bound proteins can be directed into a feedback mechanism to tune the membrane’s composition near to or within a fixed distance of a thermodynamic critical point.