New Trends in Understanding the Regulation of Red Cell Membrane Skeleton Organization

Abstract

Publisher Summary This chapter discusses the regulation of red cell membrane skeleton organization. The principal associations responsible for maintaining the integrity of the erythrocyte-membrane skeleton have been known and characterized for some time. The membrane skeleton is an interconnected network of proteins whose major constituents are spectrin, F-actin, band 4.1, and band 4.9. The spectrin molecules that are composed of two nonidentical polypeptide chains (α and β) exist principally in the form of α 2 β 2 tetramers. The protein-denoted band 4.1 plays a central role in membrane skeletal organization. The best understood role of this multifunctional protein is to promote or strengthen the association between spectrin and F-actin, one of the key skeletal interconnections. The proteins of the membrane skeleton that form a flexible two-dimensional lattice laminating the cytoplasmic membrane surface are responsible for the remarkable flexibility and resiliency of the red-cell membrane and for maintaining the shape of the normal red-blood cell. Abnormally shaped or fragile red cells that are characteristic of several types of inherited hemolytic anemias may, in some cases be the result of a genetic defect of one of the major membrane skeletal proteins.