Tight Junctions in CNS Myelin

Abstract

M yelin in the central nervous system (CNS) is composed of a complex multilamellar sheath wrapped around axons facilitating axonal conduction. Tight junctions (TJs) between plasma membrane layers of myelin were recognized over 40 years ago but only recendy has the molecular composition been determined. CNS myelin TJs stain with anti-OSP/claudin-11 antibodies and are absent when the OSP/claudin-11 gene is disrupted. These TJs, along with PLP/DM20, serve an adhesive fiinaion maintaining myelin compac-tion. In addition to its structural role in mature myelin, OSP/claudin-11 associates with a member of the tetraspanin superfamily and pi integrin, and regulates proliferation and migration of oligodendrocyte progenitor cells.