Erin D. Sheets

Nanoscale dynamics in cell surface signaling

Research in the Sheets group centers around understanding fundamental processes occurring on the cell surface that are critical for signal transduction and cellular function, and developing new tools for probing and modeling the dynamics of the molecular interactions that are involved. A major effort focuses on developing new spatially and temporally specific approaches for cell stimulation that will allow us to investigate quantitatively the critical interactions necessary for signaling. Receptor-ligand interactions that take place on the cell surface are essential for communication between the cell and its surrounding environment in processes as diverse as immune recognition, cell migration and cell differentiation. We are taking advantage of optical and engineering approaches, such as quantitative fluorescence microscopy and nanotechnology, to address very fundamental questions about signaling, which cannot be probed by more conventional means. Another project focuses on characterizing the physical behavior of specialized lipid domains (also referred to as "rafts") within model membranes and relating these dynamics to those in live cells. These rafts, which are enriched in cholesterol, participate in several signaling events, including IgE and T cell receptor signaling. By investigating the physical chemistry of rafts, we hope to gain a deeper understanding about how they function in vivo. Our cross-disciplinary laboratory capitalizes on the recent advances from many different fields to answer biological questions ranging from the physical chemistry of lipids to the initiation of signal transduction to cell motility.