The challenge of lipid rafts.

The Singer-Nicholson model of membranes postulated a uniform lipid bilayer randomly studded with floating proteins. However, it became clear almost immediately that membranes were not uniform and that clusters of lipids in a more ordered state existed within the generally disorder lipid milieu of the membrane. These clusters of ordered lipids are now referred to as lipid rafts. This review summarizes current thinking on the nature of lipid rafts focusing on the role of proteomics and lipidomics in understanding the structure of these domains. It also outlines the contribution of single-molecule methods in defining the forces that drive the formation and dynamics of these membrane domains.