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. 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. Isoform 1 and isoform 2 are correctly targeted to the lysosomal compartment and are functional enzymes. Widely expressed, with highest level in leukocytes, heart, liver, skeletal muscle, lung, placenta and liver. 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. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. A signal sequence is predicted but has been shown not to be cleaved in the reticulum endoplasmic. Intralysosomal proteolytic cleavage is faster and enzymatic activity higher than isoform 2.