Cell type-specific association between two types of spectrin and two types of intermediate filaments.
We have demonstrated a differential association between two types of spectrin, from erythrocytes and brain, with two types of intermediate filaments, vimentin filaments and neurofilaments. Electron microscopy showed that erythrocyte spectrin promoted the binding of vimentin filaments to red cell inside-out vesicles via lateral associations with the filaments. In vitro binding studies showed that the association of spectrin with vimentin filaments was apparently saturable, increased with temperature, and could be prevented by heat denaturation of the spectrin. Comparisons were made between erythrocyte and brain spectrin binding to both vimentin filaments and neurofilaments. We found that vimentin filaments bound more erythrocyte spectrin than brain spectrin, while neurofilaments bound more brain spectrin than erythrocyte spectrin. Our results show that both erythroid and nonerythroid spectrins are capable of binding to intermediate filaments and that such associations may be characterized by differential affinities of the various types of spectrin with the several classes of intermediate filaments present in cells. Our results also suggest a role for both erythroid and nonerythroid spectrins in mediating the association of intermediate filaments with plasma membranes or other cytoskeletal elements.
Langley
R C
RC
Department of Biomedical Research, St. Elizabeth's Hospital, Boston, MA 02135.
Cohen
C M
CM
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000648:ultrastructure; D002417:Cattle; D003598:Cytoskeletal Proteins; D003599:Cytoskeleton / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000378:metabolism; D006801:Humans; D007382:Intermediate Filaments / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D008565:Membrane Proteins / Q000097:blood; D008854:Microscopy, Electron; D009479:Neuropeptides; D011485:Protein Binding; D013049:Spectrin / Q000378:metabolism*; D014746:Vimentin / Q000378:metabolism
D001798:Blood Proteins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D009479:Neuropeptides; D014746:Vimentin; C028841:erythrocyte membrane band 4.1 protein; C120557:erythrocyte membrane protein band 4.1-like 1; D013049:Spectrin