title: Immunoelectron microscopic localization of s-100 protein in cultured rat glioma cells.
abstract: Immunoelectron microscopic localization of the nervous system specific protein S-100 in the cultured rat glioma cells was successfully conducted by an unique immunocytochemical technique using peroxidase-labeled antigen binding Fab' fragments. The intensely electron dense reaction product for S-100 protein was localized mainly at ribosome granules associated with endoplasmic reticulum membranes and at free ribosome granules. S-100 protein was also associated to some extent with the cytoplasmic and nuclear membranes. A positive reaction was localized at the nuclear pores as if it were being prevented from entering into the nucleus. No activity was found in the nucleoplasm except for a slightly positive reaction product associated with nucleolus. The possible role for S-100 protein in neural cells was discussed in relation to the nuclear acidic proteins involved in genomic regulation.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005910:Glioma / Q000032:analysis*; D007124:Immunoenzyme Techniques; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009685:Nuclear Envelope / Q000648:ultrastructure; D051381:Rats; D012270:Ribosomes / Q000648:ultrastructure; D009418:S100 Proteins / Q000032:analysis*
chemical_list: D009419:Nerve Tissue Proteins; D009418:S100 Proteins