title: Molecular cloning and expression of the pituitary glycoprotein hormone N-acetylgalactosamine-4-O-sulfotransferase.
abstract: N-Linked oligosaccharides terminating with the sequence SO(4)-4-GalNAcbeta1,4GlcNAcbeta1,2Manalpha are present on the pituitary hormones lutropin (LH), thyrotropin, and pro-opiomelanocortin. The sulfated structures on LH are essential for expression of its biologic function in vivo. We have cloned the N-acetylgalactosamine-4-sulfotransferase (GalNAc-4-ST1, GenBank(TM) accession number ), which mediates sulfate addition to the N-linked oligosaccharides on LH and other pituitary glycoproteins with terminal (beta1,4-linked GalNAc based on its homology to HNK-1 sulfotransferase (HNK-1 ST). GalNAc-4-ST1 displays 23% identity to HNK-1 ST and 28% to chondroitin 4-sulfotransferase 1 (C4ST-1) and 26% to chondroitin 4-sulfotransferase 2 (C4ST-2). The cDNA predicts a type II transmembrane protein of 424 amino acids with four potential N-linked glycosylation sites and a single membrane-spanning domain. GalNAc-4-ST1 has putative 5'-phosphosulfonate and 3'-phosphate binding sites. Three more carboxyl-terminal regions of unknown function also show a high degree of identity with HNK-1 ST, C4ST-1, and C4ST-2. The membrane-bound form of GalNAc-4-ST1 transfers sulfate to GalNAcbeta1, 4GlcNAcbeta-R but not to chondroitin, whereas truncated forms of GalNAc-4-ST1 that are released into the medium transfer sulfate to both GalNAcbeta1,4GlcNAcbeta-R and chondroitin. The first 118 amino acids of GalNAc-4-ST1 appear to contribute to both its activity and specificity for terminal beta1,4-linked GalNAc. GalNAc-4-ST1 also efficiently transfers sulfate to N-linked oligosaccharides on native LH and other glycoproteins terminating with beta1,4-linked GalNAc. A single transcript of 2.4 kilobases is most highly expressed in the pituitary and other regions of the central nervous system. The GalNAc-4-ST1 gene is located on human chromosome 19q13.1.
authors.affiliation: Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: G
authors.initials: G
authors.lastname: Xia
authors.forename: M R
authors.initials: MR
authors.lastname: Evers
authors.forename: H G
authors.initials: HG
authors.lastname: Kang
authors.forename: M
authors.initials: M
authors.lastname: Schachner
authors.forename: J U
authors.initials: JU
authors.lastname: Baenziger
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002240:Carbohydrate Sequence; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19; D003001:Cloning, Molecular; D006224:Cricetinae; D006801:Humans; D007986:Luteinizing Hormone / Q000378:metabolism; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry; D010908:Pituitary Hormones, Anterior / Q000737:chemistry / Q000378:metabolism*; D011333:Pro-Opiomelanocortin / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015238:Sulfotransferases / Q000235:genetics* / Q000378:metabolism*; D013972:Thyrotropin / Q000378:metabolism; D014162:Transfection
chemical_list: D009844:Oligosaccharides; D010908:Pituitary Hormones, Anterior; D011994:Recombinant Proteins; D011333:Pro-Opiomelanocortin; D007986:Luteinizing Hormone; D013972:Thyrotropin; C498300:CHST9 protein, human; C092527:N-acetylgalactosamine-4-sulfotransferase; D015238:Sulfotransferases