title: Expression of heparan sulphate L-iduronyl 2-O-sulphotransferase in human kidney 293 cells results in increased D-glucuronyl 2-O-sulphation.
abstract: Functionally important interactions between heparan sulphate and a variety of proteins depend on the precise location of O-sulphate groups. Such residues occur at C-2 of L-iduronic (IdoA) and D-glucuronic acid (GlcA) units, and at C-3 and C-6 of D-glucosamine (GlcN) units. Stable transfection of human embryonic kidney 293 cells with a cDNA encoding mouse mastocytoma IdoA 2-O-sulphotransferase resulted in an approx. 6-fold increase in O-sulphotransferase activity, compared with control cells, as determined using O-desulphated heparin as an acceptor. Structural analysis of endogenous heparan sulphate in the transfected cells, following metabolic labelling with either [(3)H]GlcN or [(35)S]sulphate, showed appreciable formation of -GlcA(2-OSO(3))-GlcNSO(3)- disaccharide units (6% of total disaccharide units; 17% of total O-sulphated disaccharide units) that were essentially absent from heparan sulphate from control cells. The increase in GlcA 2-O-sulphation was accompanied by a decrease in the amount of IdoA formed, whereas overall 2-O-sulphation or 6-O-sulphation remained largely unaffected. These findings indicate that 2-O-sulphation of IdoA and GlcA residues is catalysed by the same enzyme in heparan sulphate biosynthesis.
authors.affiliation: Department of Medical Biochemistry and Microbiology, University of Uppsala, The Biomedical Center, Box 582, S-751 23 Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Rong
authors.forename: H
authors.initials: H
authors.lastname: Habuchi
authors.forename: K
authors.initials: K
authors.lastname: Kimata
authors.forename: U
authors.initials: U
authors.lastname: Lindahl
authors.forename: M
authors.initials: M
authors.lastname: Kusche-Gullberg
mesh_terms: D000818:Animals; D002238:Carbohydrate Epimerases / Q000378:metabolism*; D002460:Cell Line; D005965:Glucuronates / Q000378:metabolism; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D015238:Sulfotransferases / Q000378:metabolism*
chemical_list: D005965:Glucuronates; D019812:Heparan Sulfate Proteoglycans; D015238:Sulfotransferases; C406782:heparan sulfate L-iduronyl 2-O-sulfotransferase; D002238:Carbohydrate Epimerases