Interaction domains of neurofilament light chain and brain spectrin.
We have previously demonstrated that brain spectrin binds to the low-molecular-mass subunit of neurofilaments (NF-L) [Frappier, Regnouf & Pradel (1987) Eur. J. Biochem. 169, 651-657]. In the present study, we seek to locate their respective binding domains. In the first part we demonstrate that brain spectrin binds to a 20 kDa domain of NF-L. This domain is part of the rod domain of neurofilaments and plays a role in the polymerization process. However, the polymerization state does not seem to have any influence on the interaction. In the second part, we provide evidence that NF-L binds to the beta-subunit of not only brain spectrin but also human and avian erythrocyte spectrins. The microtubule-associated protein, MAP2, which has also been shown to bind to microfilaments and neurofilaments, binds to the same domain of NF-L as spectrin does. Finally, among the tryptic peptides of brain spectrin, we show that some peptides of low molecular mass (35, 25, 20 and 18 kDa) co-sediment with either NF-L or F-actin.
Frappier
T
T
C.N.R.S. U.A. 1089, Laboratoire de Biophysique, Institut de Biologie Physico-Chimique, Paris, France.
Stetzkowski-Marden
F
F
Pradel
L A
LA
D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D007381:Intermediate Filament Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D007382:Intermediate Filaments / Q000378:metabolism / Q000648:ultrastructure; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008970:Molecular Weight; D016900:Neurofilament Proteins; D011485:Protein Binding; D013049:Spectrin / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D013116:Spinal Cord / Q000378:metabolism*; D013552:Swine
D007381:Intermediate Filament Proteins; D046911:Macromolecular Substances; D016900:Neurofilament Proteins; D013049:Spectrin