N-acetylglucosamine-1-phosphodiester alpha-N-acetylglucosaminidase is an enzyme that in humans is encoded by the NAGPA gene.

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. This reaction most likely occurs in the trans-Golgi network. This enzyme functions as a homotetramer of two disulfide-linked homodimers. In addition to having an N-terminal signal peptide, the protein's C-terminus contains multiple signals for trafficking it between lysosomes, the plasma membrane, and trans-Golgi network. [provided by RefSeq, Jul 2008]. Sequence Note: This RefSeq record was created from transcript and genomic sequence data to make the sequence consistent with the reference genome assembly. The genomic coordinates used for the transcript record were based on transcript alignments.
Function: Catalyzes the second step in the formation of the mannose 6-phosphate targeting signal on lysosomal enzyme oligosaccharides by removing GlcNAc residues from GlcNAc-alpha-P-mannose moieties, which are formed in the first step.