Hydrolases are transported to lysosomes after binding to mannose 6-phosphate receptors in the trans-Golgi network. This gene encodes the enzyme that catalyzes the second step in the formation of the mannose 6-phosphate recognition marker on lysosomal hydrolases. Commonly known as 'uncovering enzyme' or UCE, this enzyme removes N-acetyl-D-glucosamine (GlcNAc) residues from GlcNAc-alpha-P-mannose moieties and thereby produces the recognition marker. The encoded preproprotein is proteolytically processed by furin to generate the mature enzyme, a homotetramer of two disulfide-linked homodimers. Mutations in this gene are associated with developmental stuttering in human patients. [provided by RefSeq, Oct 2015].