Oligodendrocytes, the myelin-forming cells of the central nervous system, were cultured from newborn rat brain and optic nerve to allow us to analyze whether two transmembranous myelin proteins, myelin-associated glycoprotein (MAG) and proteolipid protein (PLP), were expressed together with myelin basic protein (MBP) in defined medium with low serum and in the absence of neurons. Using double l...

Oligodendrocytes synthesize the CNS myelin sheath by enwrapping axonal segments with elongations of their plasma membrane. Spatial and temporal control of membrane traffic is a prerequisite for proper myelin formation. The major myelin proteolipid protein (PLP) accumulates in late endosomal storage compartments and multivesicular bodies (MVBs). Fusion of MVBs with the plasma membrane results in...

We have investigated the patterns of postnatal brain expression and DNA binding of Gtx, a homeodomain transcription factor. Gtx mRNA accumulates in parallel with the RNAs encoding the major structural proteins of myelin, myelin basic protein (MBP), and proteolipid protein (PLP) during postnatal brain development; Gtx mRNA decreases in parallel with MBP and PLP mRNAs in the brains of myelin-defi...

Examination of brain myelin proteins by sodium dodecyl sulfate-gel electrophoresis followed by fluorography clearly showed that both proteolipid protein (PLP) and DM-20 were acylated 24 h after the intracerebral injection of 30-day-old rats with C3H]palmitic acid. The radioactivity associated with PLP remained after purification, re-electrophoresis, and fluorography. Most of the radioactivity a...

A gene encoding myelin proteolipid protein (PLP) and its smaller isoform DM20 is expressed at least 1 week before myelination. Mutations within the gene cause abnormalities in the development of premyelinating oligodendrocytes, resulting in hypomyelinating disorders. These findings suggest a premyelinating function of the PLP gene products. We previously demonstrated that PLP gene expression is...

The cervical spinal cords of 23-day-old myelin-deficient (md) rats, an X chromosome-linked myelin mutant, and their normal littermates were studied by light and electron microscopy, immunocytochemistry, and in situ hybridization. Light microscopy showed that there were scattered myelinated fibers in the md rat, particularly in the lateral and ventral columns. Ultrastructural examination of thes...

CNS myelination by oligodendrocytes requires directed transport of myelin membrane components and a timely and spatially controlled membrane expansion. In this study, we show the functional involvement of the R-soluble N-ethylmaleimide-sensitive factor attachment protein receptor (R-SNARE) proteins VAMP3/cellubrevin and VAMP7/TI-VAMP in myelin membrane trafficking. VAMP3 and VAMP7 colocalize wi...

The myelin proteolipid protein (PLP) gene (i.e., the PLP/DM20 gene) has been of some interest because of its role in certain human demyelinating diseases, such as Pelizaeus-Merzbacher disease. A substantial amount of evidence, including neuronal pathology in knock-out and transgenic animals, suggests the gene also has functions unrelated to myelin structure, but the products of the gene respons...

Experimental autoimmune encephalomyelitis (EAE) induced with myelin proteolipid protein (PLP) residues 139-151 (HSLGKWLGHPDKF) can be prevented by treatment with a T cell receptor (TCR) antagonist peptide (L144/R147) generated by substituting at the two principal TCR contact residues in the encephalitogenic peptide. The TCR antagonist peptide blocks activation of encephalitogenic Th1 helper cel...