Neuroplastin (NPTN)

Neuroplastin is a type I transmembrane protein belonging to the Ig superfamily. The protein is believed to be involved in cell-cell interactions or cell-substrate interactions. The alpha and beta transcripts show differential localization within the brain.

The deduced mature Gp55 and Gp65 proteins contain 253 and 365 amino acid residues with calculated molecular masses of 28.8 and 41.4 kD, respectively. Both species contain a single putative membrane spanning domain, and Gp55 has 2 extracellular Ig domains whereas Gp65 has 3 extracellular Ig domains. Gp55 shares similarity with basigin Ig domain proteins. Immunocytochemical studies localized Gp55 and Gp65 to the cell membrane in HEK293 cells.