Prosaposin is a precursor of four lysosomal saposin proteins (saposin A, B, C and D). Saposins are heat-stable glycoproteins that facilitate the catabolism of glycosphingolipids with short oligosaccharide groups. It stimulates neurite outgrowth and increases choline acetyltransferase activity. Secreted prosaposin is presumed to have additional functions in human milk, cerebrospinal fluid and seminal plasma.
- References to SAP Protein (Proactivator polypeptide, Prosaposin, PSAP)