Erythrocyte and brain forms of spectrin in cerebellum: distinct membrane-cytoskeletal domains in neurons.

Chicken cerebellum expresses a polypeptide antigenically and biochemically related to the alpha subunit of spectrin, an erythrocyte membrane-cytoskeletal protein. Most of this polypeptide is associated with a brain specific spectrin subunit, gamma-spectrin, and is localized in virtually all neuronal cell bodies and processes. Cerebellum also expresses polypeptides antigenically related to the beta subunits of erythrocyte spectrin and these are also found in association with cerebellar alpha-spectrin but are confined to the plasmalemma of the neuronal cell bodies. This suggests that there is a mechanism for segregating different spectrin complexes into distinct membrane domains within a single cell.