NDST2 (N-Deacetylase/N-Sulfotransferase-2) Enzyme Regulates Heparan Sulfate Chain Length*♦
- Audrey Deligny‡,
- Tabea Dierker‡1,
- Anders Dagälv‡1,
- Anders Lundequist‡1,
- Inger Eriksson‡,
- Alison V. Nairn§,
- Kelley W. Moremen§,
- Catherine L. R. Merry‡2 and
- Lena Kjellén‡3
- From the ‡Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, SE-75123 Uppsala, Sweden and
- the §Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
- ↵3 To whom correspondence should be addressed: Dept. of Medical Biochemistry and Microbiology, the Biomedical Center, Box 582, SE-751 23 Uppsala, Sweden. Tel.: 46-18-4714217; E-mail: lena.kjellen{at}imbim.uu.se.
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↵1 These authors contributed equally to this work.
Abstract
Analysis of heparan sulfate synthesized by HEK 293 cells overexpressing murine NDST1 and/or NDST2 demonstrated that the amount of heparan sulfate was increased in NDST2- but not in NDST1-overexpressing cells. Altered transcript expression of genes encoding other biosynthetic enzymes or proteoglycan core proteins could not account for the observed changes. However, the role of NDST2 in regulating the amount of heparan sulfate synthesized was confirmed by analyzing heparan sulfate content in tissues isolated from Ndst2−/− mice, which contained reduced levels of the polysaccharide. Detailed disaccharide composition analysis showed no major structural difference between heparan sulfate from control and Ndst2−/− tissues, with the exception of heparan sulfate from spleen where the relative amount of trisulfated disaccharides was lowered in the absence of NDST2. In vivo transcript expression levels of the heparan sulfate-polymerizing enzymes Ext1 and Ext2 were also largely unaffected by NDST2 levels, pointing to a mode of regulation other than increased gene transcription. Size estimation of heparan sulfate polysaccharide chains indicated that increased chain lengths in NDST2-overexpressing cells alone could explain the increased heparan sulfate content. A model is discussed where NDST2-specific substrate modification stimulates elongation resulting in increased heparan sulfate chain length.
Footnotes
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↵* This work was supported by grants from the Swedish Research Council (to L. K.), the Swedish Cancer Society (to L. K.), Stiftelsen för Proteoglykanforskning (to L. K.), and DAAD, German Academic Exchange Service (to T. D.), an International Academic Fellowship from the Leverhulme Trust (to C. L. R. M.), and National Institutes of Health Grant GM103490 (to K. M.). The authors declare that they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
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↵♦ This article was selected as a Paper of the Week.
- Received June 20, 2016.
- © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
