It is a 4 transmembrane domain protein which is proposed to bind other copies of itself on the extracellular side of the membrane.

This protein may play a role in the compaction, stabilization, and maintenance of myelin sheaths, as well as in oligodendrocyte development and axonal survival.

Mutations associated with this gene cause X-linked Pelizaeus–Merzbacher disease and spastic paraplegia type 2.

Two transcript variants encoding distinct isoforms have been identified for this gene.

[5] In melanocytic cells PLP1 gene expression may be regulated by MITF.