spectrinankyrin

Spectrinankyrin refers to the spectrin–ankyrin complex, a core component of the membrane skeleton that underlies the inner surface of the plasma membrane in many animal cells. The complex is formed by spectrin tetramers—comprising two α-spectrin and two β-spectrin subunits—that are bound by ankyrin adaptor proteins. Ankyrin family members (ANK1, ANK2, ANK3) connect spectrin to a range of integral membrane proteins, including the anion exchanger band 3, Na+/K+ ATPases, and various ion channels and cell adhesion molecules, thereby linking the membrane to the spectrin–actin cytoskeleton and helping organize membrane domains.

Functionally, the spectrin–ankyrin network provides mechanical stability and elasticity to the plasma membrane, maintains cell shape, and coordinates localization and turnover of membrane proteins. In erythrocytes, the complex anchors membrane proteins to the cytoskeleton via the spectrin–band 3 axis, often with support from the cytoskeletal linker protein 4.1R. In neurons, ankyrin-G (often in complex with spectrin) clusters voltage-gated sodium channels at the axon initial segment and nodes of Ranvier, contributing to action potential initiation and propagation.

Clinical relevance is noted for defects in spectrin or ankyrin genes, which can cause hereditary spherocytosis and related hemolytic anemias, as well as potential disruptions in neuronal organization and signaling in some disorders. The spectrin–ankyrin network is evolutionarily conserved and regulated by phosphorylation and interactions with other cytoskeletal components, reflecting its central role in membrane integrity and cellular organization.