Alternative titles; symbols
HGNC Approved Gene Symbol: NDST2
Cytogenetic location: 10q22.2 Genomic coordinates (GRCh38): 10:73,801,916-73,811,820 (from NCBI)
The initial step in the processing of heparan polymers to heparan sulfate or heparin is N-deacetylation/N-sulfation. This step is catalyzed by heparan N-deacetylase/N-sulfotransferases, such as NDST2 (Humphries et al., 1998).
Using PCR of human endothelial cell cDNA with primers based on the sequence of rat liver Ndst1 (600853), Humphries et al. (1998) isolated a partial NDST2 cDNA. Using the partial cDNA to screen endothelial cell and fibroblast libraries, they isolated cDNAs corresponding to the entire NDST2 coding region. The predicted 883-amino acid protein is 70% similar to NDST1. Northern blot analysis revealed that NDST2 was expressed as a 4-kb mRNA and a less abundant 4.4-kb mRNA in all human tissues tested. The strongest expression was observed in pancreas.
Orellana et al. (1994) and Eriksson et al. (1994) cloned cDNAs encoding a heparan N-sulfotransferase from a heparin-producing mouse mastocytoma cell line. Humphries et al. (1998) reported that the predicted mouse protein is 94% identical to NDST2.
Aikawa et al. (2001) cloned mouse Ndst2, which encodes a deduced 883-amino acid protein. RT-PCR detected high Ndst2 expression in all adult mouse tissues examined and in whole mouse embryos at all developmental stages examined.
Using N-acetylheparosan purified from E. coli capsular polysaccharide as substrate, Aikawa et al. (2001) found that recombinant mouse Ndst enzymes showed distinct ratios of N-acetylglucosamine N-deacetylase to N-sulfotransferase activities. Ndst2 had similarly robust activity in both reactions with this substrate.
Heparan sulfate is modified by N- and O-sulfation and epimerization. Using RT-PCR, Holmborn et al. (2004) found that Ndst1 and Ndst2 were the major sulfotransferases expressed in mouse embryonic fibroblasts (MEFs). Ndst1 -/- and Ndst2 -/- double-knockdown MEFs synthesized heparin that completely lacked N-sulfation and showed reduced, but not eliminated, O-sulfation.
Humphries et al. (1998) determined that the NDST2 gene contains 13 exons spanning 6.5 kb. The 12 introns that interrupt the coding region occur at similar sites within the coding sequence of NDST1. The similarity of the NDST2 and NDST1 genomic organization and encoded proteins suggested to Humphries et al. (1998) that the 2 genes derive from a common ancestral gene.
Ahmed et al. (2001) stated that NDST2 is 1 of 3 genes that are nested in the introns of PCDH15 (605514).
By fluorescence in situ hybridization, Humphries et al. (1998) mapped the NDST2 gene to 10q22.
Aikawa et al. (2001) determined that 3 gene duplication events likely occurred to give rise to the 4 vertebrate NDST genes. They proposed that after the initial gene duplication event, a duplication produced NDST1 and NDST2, followed by a much later duplication that produced NDST3 (603950) and NDST4 (615039).
Forsberg et al. (1999) and Humphries et al. (1999) independently targeted disruption of the mouse Ndst2 gene by homologous recombination. Humphries et al. (1999) found that mast cells in the skeletal muscle that normally contain heparin lacked metachromatic granules and failed to store appreciable amounts of mouse mast-cell protease-4, mast-cell protease-5, and mast-cell carboxypeptidase A (114851). Mast cells developed from the bone marrow of the Ndst2 -/- mice contained high levels of various protease transcripts and had substantial amounts of mast-cell protease-6 (191080) protein in their granules. However, they failed to express mast-cell protease-5 and mast-cell carboxypeptidase A. Humphries et al. (1999) concluded that heparin controls, through a posttranslational mechanism, the levels of specific cassettes of positively charged proteases inside mast cells. Forsberg et al. (1999) found that their Ndst2 knockout mice were unable to synthesize sulfated heparin. The mice were viable and fertile, as were those of Humphries et al. (1999), but had fewer connective tissue-type mast cells. The connective tissue-type mast cells had an altered morphology and contained severely reduced amounts of histamine and mast-cell proteases. Commenting on the papers by Forsberg et al. (1999) and Humphries et al. (1999), Zehnder and Galli (1999) stated that heparin had long been thought to be a storage site in the mast-cell granule for the positively charged amines histamine and serotonin. Forsberg et al. (1999) reported that the peritoneal mast cells in their Ndst2-deficient mice showed a large--roughly 94%--reduction in cell-associated histamine. Humphries et al. (1999), however, reported a more modest reduction of about 30%. Zehnder and Galli (1999) suggested that the discrepancies may be related to the variation in the age of the mice studied, as mast cells can be long-lived and accumulate additional granules with age, or that the differences may be strain-dependent.
Ahmed, Z. M., Riazuddin, S., Bernstein, S. L., Ahmed, Z., Khan, S., Griffith, A. J., Morell, R. J., Friedman, T. B., Riazuddin, S., Wilcox, E. R. Mutations of the protocadherin gene PCDH15 cause Usher syndrome type 1F. Am. J. Hum. Genet. 69: 25-34, 2001. [PubMed: 11398101] [Full Text: https://doi.org/10.1086/321277]
Aikawa, J., Grobe, K., Tsujimoto, M., Esko, J. D. Multiple isozymes of heparan sulfate/heparin GlcNAc N-deacetylase/GlcN N-sulfotransferase: structure and activity of the fourth member, NDST4. J. Biol. Chem. 276: 5876-5882, 2001. [PubMed: 11087757] [Full Text: https://doi.org/10.1074/jbc.M009606200]
Eriksson, I., Sandback, D., Ek, B., Lindahl, U., Kjellen, L. cDNA cloning and sequencing of mouse mastocytoma glucosaminyl N-deacetylase/N-sulfotransferase, an enzyme involved in the biosynthesis of heparin. J. Biol. Chem. 269: 10438-10443, 1994. [PubMed: 8144627]
Forsberg, E., Pejler, G., Ringvall, M., Lunderius, C., Tomasini-Johansson, B., Kusche-Gullberg, M., Eriksson, I., Ledin, J., Hellman, L., Kjellen, L. Abnormal mast cells in mice deficient in a heparin-synthesizing enzyme. Nature 400: 773-776, 1999. [PubMed: 10466727] [Full Text: https://doi.org/10.1038/23488]
Holmborn, K., Ledin, J., Smeds, E., Eriksson, I., Kusche-Gullberg, M., Kjellen, L. Heparan sulfate synthesized by mouse embryonic stem cells deficient in NDST1 and NDST2 is 6-O-sulfated but contains no N-sulfate groups. J. Biol. Chem. 279: 42355-42358, 2004. [PubMed: 15319440] [Full Text: https://doi.org/10.1074/jbc.C400373200]
Humphries, D. E., Lanciotti, J., Karlinsky, J. B. cDNA cloning, genomic organization and chromosomal localization of human heparan glucosaminyl N-deacetylase/N-sulphotransferase-2. Biochem. J. 332: 303-307, 1998. [PubMed: 9601056] [Full Text: https://doi.org/10.1042/bj3320303]
Humphries, D. E., Wong, G. W., Friend, D. S., Gurish, M. F., Qiu, W.-T., Huang, C., Sharpe, A. H., Stevens, R. L. Heparin is essential for the storage of specific granule proteases in mast cells. Nature 400: 769-772, 1999. [PubMed: 10466726] [Full Text: https://doi.org/10.1038/23481]
Orellana, A., Hirschberg, C. B., Wei, Z., Swiedler, S. J., Ishihara, M. Molecular cloning and expression of a glycosaminoglycan N-acetylglucosaminyl N-deacetylase/N-sulfotransferase from a heparin-producing cell line. J. Biol. Chem. 269: 2270-2276, 1994. [PubMed: 8294485]
Zehnder, J. L., Galli, S. J. Mast-cell heparin demystified. Nature 400: 714-715, 1999. [PubMed: 10466718] [Full Text: https://doi.org/10.1038/23360]