||Sulfatases, such as ARSG, hydrolyze sulfate esters from sulfated steroids, carbohydrates, proteoglycans, and glycolipids. They are involved in hormone biosynthesis, modulation of cell signaling, and degradation of macromolecules. This gene, a novel arylsulfatase, has activity toward pseudosubstrates including p-nitrocatechol sulfate and 4-methylumbelliferyl sulfate. Activity is competitively inhibited by phosphate. The unprocessed protein is active as a 63-kDa monomer and demonstrates an acidic pH optimum as typically seen for lysosomal sulfatases. The protein accumulates within lysosomes and is also a glycoprotein that binds specifically to mannose 6-phosphate receptors.