Lysosomal acetyltransferase that acetylates the non-reducing terminal alpha-glucosamine residue of intralysosomal heparin or heparan sulfate, converting it into a substrate for luminal alpha-N-acetyl glucosaminidase. acetyl-CoA + alpha-D-glucosaminyl-[heparan sulfate](n) = CoA + H(+) + N-acetyl-alpha-D-glucosaminyl-[heparan sulfate](n) Homooligomer. Homooligomerization is necessary for enzyme activity (By similarity). Colocalizes with the lysosomal marker LAMP2. The signal peptide is not cleaved upon translocation into the endoplasmic reticulum; the precursor is probably targeted to the lysosomes via the adapter protein complex-mediated pathway that involves tyrosine- and/or dileucine-based conserved amino acid motifs in the last C-terminus 16-amino acid domain (By similarity). Expressed in the retina. Expressed in the developing eye as early as 14 dpc, with equal high expression levels after birth (postnatal day 1 (P1) and postnatal day 30 (P30)). Undergoes intralysosomal proteolytic cleavage; occurs within the end of the first and/or the beginning of the second luminal domain and is essential for the activation of the enzyme. Glycosylated. A signal sequence is predicted but has been shown not to be cleaved in the reticulum endoplasmic. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.