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Ultrastructural Localization of P 2 Protein in Actively Myelinating Rat Schwann Cells
Author(s) -
Trapp Bruce D.,
DuboisDalcq Monique,
Quarles Richard H.
Publication year - 1984
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1984.tb12828.x
Subject(s) - cytoplasm , myelin , axon , schwann cell , antiserum , organelle , cytosol , immunocytochemistry , biology , membrane , staining , microbiology and biotechnology , ultrastructure , axolemma , biochemistry , anatomy , antibody , central nervous system , immunology , neuroscience , genetics , endocrinology , enzyme
The myelin specific protein, P 2 , was localized immunocytochemically in electron micrographs of 4‐day‐old rat peripheral nerve by a preembedding technique. P 2 staining was restricted to Schwann cells that had established a one‐to‐one relationship with an axon. P 2 antiserum produced a diffuse staining throughout the entire cytosol of myelinating Schwann cells. In addition, the cytoplasmic side of Schwann cell plasma membranes and the membranes of cytoplasmic organelles that were exposed to cytosol were stained by P 2 antiserum. This cytoplasmic localization of P 2 protein is similar to that described for soluble or peripheral membrane proteins that are synthesized on free ribosomes. P 2 antiserum stained the cytoplasmic side of Schwann cell membranes that formed single or multiple loose myelin spirals around an axon. In the region of the outer mesaxon, P 2 antiserum stained the major dense line of compact myelin. These results demonstrate that P 2 protein is located on the cytoplasmic side of compact myelin membranes and are consistent with biochemical studies demonstrating P 2 to be a peripheral membrane protein.