Proteolytic cleavage of the disease-related lysosomal membrane glycoprotein CLN7

► The lysosomal membrane glycoprotein CLN7 is proteolytically cleaved in lysosomes. ► Proteolytic cleavage can be mediated by cathepsin L and occurs in luminal loop L9. ► CLN7 cleavage occurs gradually and cleavage products are relatively stable. ► Disease-associated mutations in CLN7 result in increased proteolytic cleavage.