Figure 1: 4.1R80 interaction with membrane proteins in erythrocytes. Organization of the erythrocyte plasma membrane. A protein network forming a “cytoskeleton” underlies the cytoplasmic surface of the red blood cell lipid bilayer spectrin spectrin (α and β), actin, 4.1R, p55 and ankyrin are the main constituents of the skeleton. Interactions between these proteins are defined as lateral interactions. This protein network is anchored to the lipid bilayer through two vertical interactions, one involving ankyrin and band 3, the other one involving 4.1R80, p55 and GPC. The organization of several additional actinassociated proteins, including myosin, protein 4.9, adducin and tropomodulin is presented in figure 2A.