title: Differential expression and enzymatic properties of GalNAc-4-sulfotransferase-1 and GalNAc-4-sulfotransferase-2.
abstract: We have cloned two GalNAc-4-sulfotransferases, GalNAc-4-ST1 and GalNAc-4-ST2, that transfer sulfate to terminal beta1,4-linked GalNAc. In conjunction with the action of protein-specific beta1,4GalNAc-transferases, GalNAc-4-ST1 and GalNAc-4-ST2 account for the presence of terminal beta1,4-linked GalNAc-4-SO(4) on glycoproteins such as lutropin, thyrotropin (TSH), proopiomelanocortin (POMC), carbonic anhydratase-VI (CA-VI), and tenascin-R. GalNAc-4-ST1 and GalNAc-4-ST2 can be distinguished by their differing specificity for oligosaccharide acceptors and temperature lability. The differences in properties have been used to show that the levels of GalNAc-4-ST1 and GalNAc-4-ST2 activity are proportionate to the levels of their respective transcripts. Furthermore, we have found that both transcript and activity levels of GalNAc-4-ST1 and GalNAc-4-ST2 vary widely among different tissues indicating that the regulation of their expression differs. Differences in specificity and the regulation of expression may account for existence of two GalNAc-4-sulfotransferases in vivo. The highest levels of both GalNAc-4-ST1 and GalNAc-4-ST2 transcripts are present in the pituitary of the mouse with multiple cell types that produce glycoproteins terminating with GalNAc-4-SO(4). Genetic ablation of both GalNAc-4-ST1 and GalNAc-4-ST2 may be necessary to alter the pattern and/or extent of sulfate addition to terminal beta1,4GalNAc in tissues such as pituitary.
authors.affiliation: Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Rajeev K
authors.initials: RK
authors.lastname: Boregowda
authors.forename: YiLing
authors.initials: Y
authors.lastname: Mi
authors.forename: Hongyin
authors.initials: H
authors.lastname: Bu
authors.forename: Jacques U
authors.initials: JU
authors.lastname: Baenziger
mesh_terms: D000818:Animals; D016466:CHO Cells; D002256:Carbonic Anhydrases / Q000737:chemistry; D002412:Cations; D003001:Cloning, Molecular; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007986:Luteinizing Hormone / Q000737:chemistry; D051379:Mice; D009419:Nerve Tissue Proteins; D009844:Oligosaccharides / Q000737:chemistry; D010902:Pituitary Gland / Q000201:enzymology; D011333:Pro-Opiomelanocortin / Q000737:chemistry; D021122:Protein Subunits / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D012335:RNA, Ribosomal / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013379:Substrate Specificity; D013431:Sulfates / Q000737:chemistry; D015238:Sulfotransferases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D013696:Temperature; D019063:Tenascin / Q000737:chemistry; D013972:Thyrotropin / Q000737:chemistry; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D002412:Cations; D009419:Nerve Tissue Proteins; D009844:Oligosaccharides; D021122:Protein Subunits; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D013431:Sulfates; D019063:Tenascin; C074638:tenascin R; D011333:Pro-Opiomelanocortin; D007986:Luteinizing Hormone; D013972:Thyrotropin; C092527:N-acetylgalactosamine-4-sulfotransferase; D015238:Sulfotransferases; D002256:Carbonic Anhydrases; C477051:carbonic anhydrase VI