NAGPA
Domain
The tyrosine-based internalization signal may be essential for its retrieval from the plasma membrane to the TGN.
The C-terminal NPFKD sequence is an attractive candidate for either an endocytosis signal acting at the plasma membrane or a retrieval signal acting at the TGN to return the enzyme to the cis/medial-Golgi.
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. Also hydrolyzes UDP-GlcNAc, a sugar donor for Golgi N-acetylglucosaminyltransferases.
Involvement in disease
Defects in NAGPA have been suggested to play a role in susceptibility to persistent stuttering. Stuttering is a common speech disorder characterized by repetitions, prolongations, and interruptions in the flow of speech.
Pathway
Protein modification; protein glycosylation.
Post-translational modifications
The precursor is cleaved and activated in the trans-Golgi network by a furin endopeptidase.
Tissue Specificity
Isoform 2 may be brain-specific.
Cellular localization
- Golgi apparatus
- Golgi stack membrane
- Single-pass type I membrane protein
- Golgi apparatus
- trans-Golgi network
- Cis/medial Golgi.
Alternative names
N-acetylglucosamine-1-phosphodiester alpha-N-acetylglucosaminidase, Mannose 6-phosphate-uncovering enzyme, Phosphodiester alpha-GlcNAcase, NAGPA