PSAP/Prosaposin Protein, Human (HEK293, His)

The PSAP/Prosaposin Protein, encoded by this gene, is a highly conserved preproprotein that undergoes proteolytic processing to yield four main cleavage products—saposins A, B, C, and D. Each domain of the precursor protein, approximately 80 amino acid residues long, exhibits nearly identical placement of cysteine residues and glycosylation sites. Saposins A-D primarily localize to the lysosomal compartment, where they play a crucial role in facilitating the catabolism of glycosphingolipids with short oligosaccharide groups. The precursor protein exists in both secretory and integral membrane forms and possesses neurotrophic activities. Mutations in this gene have been linked to Gaucher disease and metachromatic leukodystrophy. Alternative splicing yields multiple transcript variants, with at least one encoding an isoform that undergoes proteolytic processing. The gene displays ubiquitous expression, with elevated levels detected in the spleen (RPKM 523.6), gall bladder (RPKM 491.5), and 25 other tissues, emphasizing its essential role across various physiological contexts in multiple organs.