New insights into red cell network structure, elasticity, and spectrin unfolding--a current review.

The red cell membrane's well-recognized ability to withstand the stresses of circulation clearly has its origins in various levels of spectrin-actin network structure. We highlight recently obtained insights into this sub-structure and also briefly explain the implications to membrane components that interact with the network. Novel insights into the resilience of this cytoskeleton are being provided by experiments that range from atomic force microscopy (AFM) tests of single, unfoldable spectrin chains to micropatterned photobleaching of a pipette-deformed network. Continued progress in atomic level structure determinations of non-erythroid spectrin and related repeats are further complemented by theoretical efforts--computational approaches most notably--that have begun to correlate molecular scale aspects of structure with micro-mechanical measures. All of this recent activity in the biophysics of red cell structure-function challenges and refines some of the most basic tenets in cell membrane response.