NYU School of Medicine
November 13, 2012
Structural characterization of the Red Blood Cell skeleton by Cryoelectron Tomography
During its passage through the circulation, an erythrocyte must repeatedly squeeze through very small capillaries and undergo extensive passive deformation, yet, it needs to be stable to resist fragmentation. The ability of the red blood cell (RBC) to do so is essential for both its function and its survival. The red blood cell is unique among eukaryotic cells in that its principal structure is its membrane, which encloses a concentrated hemoglobin solution, thus, all of the structural properties of this cell are in one way or another linked to the cell membrane. The RBC membrane is composed of a lipid bilayer to which is anchored a filamentous network of proteins that underlies the cytoplasmic surface of the membrane. This network, also referred to as the membrane skeleton or cytoskeleton, has been extensively studied by many biochemical and biophysical methods, both as a model membrane system and to investigate its role in gas exchange and transport. Yet, our understanding of the ultrastructural aspects of the network is still limited. We have used cryoelectron tomography in an effort to clearly visualize the cytoskeletal network structure in very close to native conditions and obtain an empirically determined 3D structure that reveals the supramolecular organization of the cytoskeleton and the nature of its intermolecular contacts. In this talk I will present the results of our work.