MEMBRANE ADHESION AND OTHER FUNCTIONS FOR THE MYELIN BASIC-PROTEINS

The myelin basic proteins are a set of peripheral membrane polypeptide s which play an essential role in myelination. Their most well-documen ted property is the unique ability to 'seal' the cytoplasmic aspects o f the myelin membrane, but this is probably not the only function for these highly charged molecules. Despite extensive homology, the indivi dual myelin basic proteins (MBPs) exhibit different expression pattern s and biochemical properties, and so it is now believed that the vario us isoforms are not functionally equivalent in myelinating cells. We n ow think that while the major MBPs are intracellular adhesion molecule s, some of the quantitatively less abundant isoforms that are expresse d very early in development may have regulatory effects on the myelina tion program.