Overexpression of different isoforms of glucosaminyl N-deacetylase/N-sulfotransferase results in distinct heparan sulfate N-sulfation patterns

Biochemistry. 2000 Apr 18;39(15):4552-8. doi: 10.1021/bi992524l.

Abstract

Functional interactions of heparan sulfate (HS) with selected proteins depend on distinct saccharide sequences which are generated during biosynthesis of the polysaccharide. Glucosaminyl N-deacetylase/N-sulfotransferases (NDSTs) catalyze both the N-deacetylation and N-sulfation reactions that initiate the modification of the (GlcNAc-GlcA)(n) polysaccharide backbone. The N-acetyl/N-sulfate exchange is restricted to certain regions of the polysaccharide chains, and only these can be further modified by glucuronyl C5-epimerization and O-sulfation at various positions. To investigate whether NDST isoforms influenced differently the structure of HS, murine NDST-1 was overexpressed in human kidney 293 cells, and the structure of the HS produced was compared to HS from NDST-2 overexpressing cells [Cheung, W. F., Eriksson, I., Kusche-Gullberg M., Lindahl, U., and Kjellén, L. (1996) Biochemistry 35, 5250-5256]. The level of N-sulfation increased from 40% in control cells to 60% and 80%, respectively, in NDST-1 and NDST-2 transfected cells. Interestingly, the increase in N-sulfation was accompanied by an increased chain length, while no effect on IdoA content or O-sulfation was seen. The most extended N-sulfated domains were found in HS synthesized by NDST-2 transfected cells. Since both the N-deacetylase and the N-sulfotransferase activities were lower in these cells than in the NDST-1 overexpressing cells, we conclude that, in addition to the level of enzyme expression, the NDST isoform also is important in determining the N-sulfation pattern in HS.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Amidohydrolases / metabolism*
  • Animals
  • Cell Line
  • Chromatography, Gel
  • Disaccharides / analysis
  • Disaccharides / chemistry
  • Glucuronic Acid / analysis
  • Heparitin Sulfate / chemistry*
  • Heparitin Sulfate / isolation & purification
  • Heparitin Sulfate / metabolism*
  • Humans
  • Iduronic Acid / analysis
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Mice
  • Molecular Weight
  • Polysaccharides / chemistry
  • Polysaccharides / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sulfates / analysis
  • Sulfates / chemistry
  • Sulfates / metabolism*
  • Sulfotransferases / genetics
  • Sulfotransferases / metabolism*
  • Transfection

Substances

  • Disaccharides
  • Isoenzymes
  • Polysaccharides
  • RNA, Messenger
  • Sulfates
  • Iduronic Acid
  • Glucuronic Acid
  • Heparitin Sulfate
  • NDST2 protein, human
  • Ndst2 protein, mouse
  • Sulfotransferases
  • heparitin sulfotransferase
  • Amidohydrolases