Modulated adhesion: a proposal for the role of myelin-associated glycoprotein in myelin wrapping.

Abstract

Myelin-associated glycoprotein (MAG) is a 100-kDa integral membrane glycoprotein expressed by oligodendrocytes and Schwann cells in the central and peripheral nervous systems, respectively. It is found first in loosely wrapped myelin and then periaxonally after compaction. Clinical findings, structural analysis, and cell assays indicate a role for MAG in adhesion. We propose that the phosphorylation state of MAG modulates its adhesion and that a minimum spatial requirement for the separation of the kinase and phosphatase activities postulated by this model may explain the correlation between axon size and myelination state.