NDST isoforms

Four isoforms of NDST have been identified in human and mouse." " The isoforms can be divided into two subgroups NDST-1 and NDST-2 with 70% identities in amino acid sequence, andNDST-3 and NDST-4 with 80.4% identity. Those four NDST isoforms have distinct tissue expression patterns. NDST-1 and NDST-2 are expressed quite uniformly in different tissues, while the expression of NDST-3 and NDST-4 occurs predominantly in the brain. The NDST isoforms seem to have distinct deacetylase and sulfotransferase activities, with comparable levels of each. For example, NDST-3 has good deacetylase activity but very poor sulfotransferase activity, and NDST-4 shows the opposite with poor deacetylase activity and excellent sulfotransferase activity. The biological significance of the variations of the enzymatic activities of NDST isoforms is not fully understood, but it has been proposed that it may help generate unique sulfation patterns on HS." ... 

HS sulfotransferases are available, including NST-1, 3-OST-l and 3-OST-3. nST-1 is the AT-sulfotransferase domain of NDST isoform -1, which... 

Figure 1. Scheme of polymer-modification reactions in the biosynthesis of heparin/HS. In general, about half of the GlcN residues in HS, but 90% or more of those in heparin, will be A sulfated during biosynthesis. How the Af-sulfation pattern of a certain polysaccharide is regulated is not known but may in part depend on the type of NDST isoform(s) involved. 

---