Protein zero (P-0) is a member of the immunoglobulin gene superfamily
(IgCAM) that is expressed at high levels in myelinated vertebrates in
central (fish and amphibia) and peripheral (all species) myelin, This
glycoprotein is the major adhesive component of peripheral myelin, whe
re it mediates self-adhesion of the Schwann cell plasma membrane. Alth
ough the expression of P-0 is naturally limited to Schwann cells, the
molecular mechanisms of P-0-mediated adhesion can be considered genera
l and ''obligatory'' because, when expressed in a variety of cell line
s, P-0 induces strong intercellular adhesion. Modeling studies, X-ray
crystallographic analysis, and experimental site-directed mutagenesis
have provided excellent working models for understanding how P-0 media
tes adhesion at the atomic level. These models remain to be experiment
ally tested. However, in humans, certain mutations in P-0 produce dysm
yelinating disease, possibly due to disruptions in the predicted P-0 l
attice. J. Neurosci, Res. 54:137-146, 1998. (C) 1998 Wiley-Liss, Inc.