Plenary Talk: Cell Surface Topography: How Protein Size can Alter Organization and Signaling at Cell-Cell Interfaces

Membrane interfaces formed at junctions between cells are often associated with characteristic patterns of membrane protein organization, such as in epithelial tissues and between cells of the immune system. The size of cell surface proteins is emerging as a critical property that can directly affect cell-cell interface formation and contribute to spatial arrangement of membrane proteins at junctions, as well as their downstream signaling. This talk will describe a new method for characterizing cell surface protein size that enables nanometer-scale height measurements. With this information, we use in vitro systems based on giant unilamellar vesicles and live immune cells to show that fluid membrane interfaces linked by adhesion proteins can drive segregation of non-adhesive proteins, directly affecting macrophage signaling during receptor-mediated target recognition. Results from these studies support a model in which cell surface protein size plays a key role in mediating cell-cell communication and function.