A calcium-dependent mechanism for synapse and nerve cell membrane modulation.
A theory is presented according to which the neuronal membrane and synapses are influenced by membrane-bound S100 protein and a membrane-associated network of actin-like, 20-A-diameter, coiled filaments and the competition by both proteins for Ca(2+). The discussion is based on observations made with fluorescein- and peroxidase-conjugated antiserum against S100 protein on isolated nerve cells. A small part of the S100 protein is membrane-bound in a polar localization that develops postnatally. The competition for Ca(2+) can influence the state of the network filaments which uncoil on binding Ca(2+) and affect differently the conformational state of synapses and membrane depending on the S100 protein content.
D000199:Actins / Q000378:metabolism; D000818:Animals; D000906:Antibodies; D000937:Antigen-Antibody Reactions; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002469:Cell Separation; D007158:Immunologic Techniques; D008854:Microscopy, Electron; D008959:Models, Neurological; D008961:Models, Structural; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000648:ultrastructure*; D011487:Protein Conformation; D011817:Rabbits; D009418:S100 Proteins / Q000276:immunology / Q000378:metabolism*; D013569:Synapses / Q000648:ultrastructure*
D000199:Actins; D000906:Antibodies; D009419:Nerve Tissue Proteins; D009418:S100 Proteins; D002118:Calcium