title: Expression of human H-type alpha1,2-fucosyltransferase encoding for blood group H(O) antigen in Chinese hamster ovary cells. Evidence for preferential fucosylation and truncation of polylactosamine sequences.
abstract: The human H(O) blood group is specified by the structure Fucalpha1-2Galbeta1-R, but the factors regulating expression of this determinant on cell surface glycoconjugates are not well understood. To learn more about the regulation of H blood group expression, cDNA encoding the human H-type GDPFuc:beta-D-galactoside alpha1, 2-fucosyltransferase (alpha1,2FT) was stably transfected into Chinese hamster ovary (CHO) cells. The new cell line, designated CHO(alpha1,2)FT, expressed surface neoglycans containing the H antigen. The structures of the fucosylated neoglycans in CHO(alpha1, 2)FT cells and the distribution of these glycans on glycoproteins were characterized. Seventeen percent of the [3H]Gal-labeled glycopeptides from CHO(alpha1,2)FT cells bound to the immobilized H blood group-specific lectin Ulex europaeus agglutinin-I (UEA-I), whereas none from parental CHO cells bound to the lectin. The glycopeptides from CHO(alpha1,2)FT cells binding to UEA-I contained polylactosamine [3Galbeta1-4GlcNAcbeta1-]n with the terminal sequence Fucalpha1-2Galbeta1- 4GlcNAc-R. Fucosylation of the polylactosamine sequences on complex-type N-glycans in CHO(alpha1, 2)FT cells caused a decrease in both sialylation and length of polylactosamine. Unexpectedly, only small amounts of terminal fucosylation was found in diantennary complex-type N-glycans. The O-glycans and glycolipids were not fucosylated by the H-type alpha1, 2FT. Two major high molecular weight glycoproteins, one of which was shown to be the lysosome-associated membrane glycoprotein LAMP-1, preferentially contained the H-type structure and were bound by immobilized UEA-I. These results demonstrate that in CHO cells the expressed H-type alpha1,2FT does not indiscriminately fucosylate terminal galactosyl residues in complex-type N-glycans, but it favors glycans containing polylactosamine and dramatically alters their length and sialylation.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Prieto
authors.forename: R D
authors.initials: RD
authors.lastname: Larsen
authors.forename: M
authors.initials: M
authors.lastname: Cho
authors.forename: H N
authors.initials: HN
authors.lastname: Rivera
authors.forename: A
authors.initials: A
authors.lastname: Shilatifard
authors.forename: J B
authors.initials: JB
authors.lastname: Lowe
authors.forename: R D
authors.initials: RD
authors.lastname: Cummings
authors.forename: D F
authors.initials: DF
authors.lastname: Smith
mesh_terms: D000017:ABO Blood-Group System; D000606:Amino Sugars / Q000737:chemistry*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D001345:Autoradiography; D016466:CHO Cells; D002851:Chromatography, High Pressure Liquid; D002854:Chromatography, Paper; D006224:Cricetinae; D003412:Cricetulus; D005434:Flow Cytometry; D005643:Fucose / Q000378:metabolism; D005647:Fucosyltransferases / Q000378:metabolism*; D006801:Humans; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D019081:O Antigens / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D000097631:Galactoside 2-alpha-L-fucosyltransferase
chemical_list: D000017:ABO Blood-Group System; D000606:Amino Sugars; D015703:Antigens, CD; D005643:Fucose; D005647:Fucosyltransferases; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D019081:O Antigens; D011134:Polysaccharides; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C066929:polylactosamine