Role of sphingolipids in the transport of prosaposin to the lysosomes

Prosaposin is the precursor of four lysosomal saposins that promote the degradation of glycosphingolipids (GSLs) by acidic hydrolases. GSLs contain a hydrophobic ceramide moiety, which acts as a membrane anchor, and a hydrophilic oligosaccharide chain that faces the lumen of the Golgi apparatus and extracellular spaces. By using fumonisin B1, PDMP and D609, we tested the hypothesis that sphingolipids mediate the transport of prosaposin to the …