Chapter 5 Ankyrins: A Family of Proteins that Link Diverse Membrane Proteins to the Spectrin Skeleton

Spectrin is a flexible rod-shaped molecule, comprising two subunits, aligned side-to-side to form hetero-dimers and head-to-head into tetramers that are capable of cross-linking actin, with binding sites, for actin on both ends. Two classes of protein interactions have been identified as an essential for the assembly of spectrin tetramers into a membrane-associated network; linkage of spectrin to the membrane and association of multiple spectrin molecules with actin to form a two-dimensional meshwork. Principal that can be derived, from the erythrocyte membrane, is that spectrin alone does not polymerize or assemble into higher order structures without the aid of accessory proteins. This chapter discusses ankyrins that comprise an important class of spectrin-organizing proteins that are candidates to link a number of integral membrane proteins to the spectrin skeleton in specialized plasma membrane domains. The chapter discusses ankyrin structure of ankyrins being a multigene family, functional diversity of ankyrin, because of alternative splicing of messenger RNA (mRNA) and of mapping the binding sites of ankyrin. Ankyrins are a family of structural proteins, associated with the plasma membrane, that are candidates to link integral membrane proteins to the spectrin skeleton. Ankyrin-binding proteins include three different ion channels: the anion exchanger of erythrocytes and kidney collecting ducts, the Na+/K+- adenosine triphosphate (ATP)ase of kidney distal tubules, and the voltage-dependent sodium channel of the brain. © 1991, Elsevier Inc. All rights reserved.

Duke Scholars

Author Vann Bennett Biochemistry