2Department of Biochemistry, Osaka University Medical School, 22 Yamadaoka, Suita, Osaka 5650871, Japan and 3Department of Obstetrics and Gynecology, Asahikawa Medical College, Nishikagura 45311, Asahikawa, Hokkaido 0788510, Japan
Received on September 16, 1999; revised on November 12, 1999; accepted on November 15, 1999.
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Abstract |
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Key words: fucosyltransferase/N-glycan
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Introduction |
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1,6-Fucosyltransferase is widely distributed in mammalian tissues, as evidenced by activity assay and Northern hybridization (Miyoshi et al., 1997
). While oligosaccharides that contain
1,6-fucose residues are frequently found in the N-glycans of a variety of glycoproteins, this structure is not found in the serum proteins biosynthesized by the liver, probably because of the very low activity of the enzyme in hepatocytes (Campion et al., 1989
; Yamashita et al., 1989
; Noda et al., 1998a
). Nevertheless,
1,6-fucosyltransferase activity is increased in the liver for cases of certain diseased states such as hepatocellular carcinomas, and, as a result, the content of
1,6-fucose residues in the Asn-linked oligosaccharides of the serum proteins, produced in the liver, are significantly elevated in such cases (Aoyagi et al., 1985
, 1993a,b; Hutchinson et al., 1991
; Ohno et al., 1992
; Noda et al., 1998b
). It has been proposed that this structural alteration, which is associated with carcinogenesis, could be of value in the differential diagnosis of the malignant diseases.
In order to investigate the molecular basis for oligosaccharide alteration associated with the hepatocarcinogesis, we have purified 1,6-fucosyltransferase from pig brain and a human gastric cancer cell line, cloned their cDNAs, and analyzed the genomic structure of the human enzyme (Uozumi et al., 1996a
; Yanagidani et al., 1997
; Yamaguchi et al., 1999
). Structural analyses of the cDNA clones indicates that the enzyme is a type II membrane protein, and that the domain structure of the enzyme is similar to those of other classes of fucosyltransferases, as well as other glycosyltransferases. However, when the complete amino acid sequence was compared with those of the other fucosyltransferases, no remarkable homology was found among them. Only a small region in the
1,6-fucosyltransferase was found to be significantly homologous to a portion of
1,2-fucosyltransferase, based on a comparison of their sequences (Breton et al., 1998
). This suggests that the motif would be involved in functional properties which are common to the
1,2- and
1,6-fucosyltransferases.
Of the numerous fucosyltransferases, the catalytic properties of the 1,3- or
1,3/4-fucosyltransferase involved in the biosynthesis of Lewis antigens have been intensively investigated in terms of kinetic properties and catalytic mechanism (Murray et al., 1996
, 1997; Nguyen et al., 1998
; Sherwood et al., 1998
; Vo et al., 1998
). On the other hand, although Glick et al. purified the
1,6-fucosyltransferase from cultured skin fibroblasts and characterized some of the kinetic properties of the enzyme (Voynow et al., 1991
), the detailed catalytic mechanism remains unclear. Moreover, amino acid residues that are involved or essential for activity have not yet been identified. Information, as obtained by chemical modification studies or site-directed mutagenesis, would be highly desirable for the elucidation of the catalytic mechanism of the enzyme.
In this study, the residues conserved in the homologous motifs between 1,2- and
1,6-fucosyltransferases were selected as likely candidate residues which might play an essential or important role in the function of the enzyme, and then prepared mutant
1,6-fucosyltransferases in which these residues were replaced. These mutants, as well as the wild-type enzyme, were produced using a baculovirusinsect cell expression system, and were characterized by kinetic analyses to examine the role of the identified residues.
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Results |
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Discussion |
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Although it is entirely possible that the catalytic mechanism of 1,6-fucosyltransferases is similar to that of
1,2-fucosyltransferase and involves these conserved residues, it was found that Arg-366, a conserved residue, is not a significant participant in the catalysis of the enzyme.
1,6-Fucosyltransferase shares only a common donor substrate, GDP-fucose, with
1,2-fucosyltransferase, but not a common acceptor. Therefore, it can reasonably be argued that the residues play a significant role, primarily in interactions with the donor, rather than with acceptors.
The nature of the interaction of the arginine residues of 1,6-fucosyltransferase with the nucleotide sugar is not clearly known. In general, enzymes which bind nucleotides, such as, for example, kinases, appear to frequently contain the positively charged amino acid residues, Lys and Arg in the nucleotide-binding site, and these residues interact directly with diphosphate or triphosphate groups of the substrates in an electrostatic manner. Furthermore in some enzymes or proteins, even a mutation which retains a positive charge, Arg-to-Lys or Lys-to-Arg, at such a residue, interaction with the nucleotide leads to the abolition of binding (Shen et al., 1991
; Li et al., 1995
; Chan and Gill, 1996
; Tohgo et al., 1997
; Kazuta et al., 1998
). Thus, an electrostatic interaction would be the most likely interaction between the arginine residue identified in the enzyme and the nucleotide sugar. The character specific to arginine such as the capability of forming two hydrogen bonds, the bulkiness of the guanidino group, and a wider distribution of the positive charge may be of critical importance for interaction of the enzyme with the donor substrate.
In many glycosyltransferases requiring a metal ion such as Mn2+ for reaction, the metal ion is believed to allow the diphosphate moiety of the nucleotide sugar to coordinate and thus facilitate the binding to the enzymes (Powell and Brew, 1976a,b; Andree and Berliner, 1980
; Boeggeman et al., 1995
). In addition, the divalent metal ion might possibly play a role, even as an electrostatic catalyst, stabilizing the negative charge which develops on the cleavage of the donor nucleotide. On the other hand,
1,6-fucosyltransferase,
1,2-fucosyltransferase, and certain other glycosyltransferases do not require a divalent cation for reaction, and thus it is conceivable that a positively charged residue, probably arginine in this case, substitutes for the divalent metal. The absolute requirement of Arg-365 could be explained by its involvement both in substrate binding and catalysis, and, in this case, the residue might possibly serve as a substitute for the divalent metal ion. A more detailed characterization of the Arg-365-substituted mutant of
1,6-fucosyltransferase may contribute to our understanding of the catalytic mechanism of divalent metal-independent glycosyltransferases.
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Materials and methods |
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Construction of transfer plasmids
Human 1,6-fucosyltransferase cDNA, which was previously cloned in our laboratory (Yanagidani et al., 1997
), was excised from the pBluescript, and inserted into a transfer vector, pVL1393, by BamHI and EcoRI sites. The resultant plasmids were purified by a Qiagen plasmid purification kit, and then subjected to the transfection experiments.
Site-directed mutagenesis
Site-directed mutagenesis was carried out according to Kunkel (Kunkel, 1985), as described previously (Ikeda et al., 1995a
). A 0.5 kb fragment obtained by digestion of human
1,6-fucosyltransferase cDNA with HindIII was subcloned into pBluescript KS+, and the resulting plasmid was used for transformation of CJ236 (dut , ung). The uracil-substituted single stranded DNA was prepared by infection of the transformed CJ236 with helper phage M13K07. This template was used with oligonucleotide primers to replace the conserved residues. The primers used in this study were 5'-GTTATTGGAGTGGCCGTCAGACGCAC-3' for replacement of His-363 by Ala (designated as H363A), 5'-GTCCATGTCGCGCGCACAGAC-3' for Arg-365 by Ala (R365A), 5'-GTCCATGTCAGAGCCACAGACAAAG-3' for Arg-366 by Ala (R366A), 5'-GGAGTCCATGTCGCGGCCACAGACAAAGTG-3' for the double replacement of Arg-365 by Ala and Arg-366 by Ala (R365A/R366A), 5'-GGAGTCCATGTCAAGCGCACAGACAAAGTG-3' for Arg-365 by Lys (R365K), 5'-GGAGTCCATGTGCGCAAGACAGACAAAGTG-3' for Arg-366 by Lys (R366K) and 5'-GTTATTGGAGTACATGTCAAAAAGACAGACAAAGTG-3' for the double substitution of Lys for Arg-365 and Arg-366. The resulting mutations were verified by dideoxy sequencing using a DNA sequencer (Applied Biosystems, model 373A), as were the entire sequences which had been subjected to mutagenesis. The corresponding region of the wild-type
1,6-fucosyltransferase cDNA was replaced by each mutant sequence. The transfer plasmids for these mutant enzymes were constructed in a manner similar to that of the wild-type enzyme, and used for transfection.
Cell culture and general manipulation of viruses
Spodoptera frugiperda (Sf) 21 cells were maintained at 27°C in Graces insect media (GIBCO-BRL) supplemented with 10% fetal bovine serum, 3.33 g/l yeastolate, 3.33 g/l lactalbumin hydrolysate, and 100 mg/l kanamycin. Recombinant viruses were manipulated as described (Piwnica-Worms, 1987).
Preparation of recombinant viruses
The purified transfer plasmids containing the wild-type or mutant 1,6-fucosyltransferase (1 µg) were cotransfected into 5 x 105 Sf21 cells with 10 ng of BaculoGold DNA (PharMingen). Transfection experiments were carried out by the Lipofectin (GIBCO-BRL) method (Felgner et al., 1987
), as described previously (Ikeda et al., 1995b
,c). Media containing the recombinant viruses generated by homologous recombinations were collected 6 days after transfection. The recombinant viruses were further amplified to more than 5 x 107 plaque forming units/ml prior to use.
Electrophoresis and immunoblot analysis
SDS-PAGE analysis was carried out on 10% gels, according to Laemmli (Laemmli, 1970). The separated proteins were transferred onto PVDF membrane, and the resultant blot was blocked by 5% skim milk. The membrane was reacted with the anti-peptide antibody specific to porcine and human
1,6-fucosyltransferases, followed by reaction with a horseradish peroxidaseconjugated anti-rabbit IgG-antibody. The reactive bands were visualized by an ECL kit (Amersham).
Activity assay
1,6-Fucosyltransferase activity was assayed using a fluorescence-labeled sugar chain substrate, according to the method of Uozumi (Uozumi et al., 1996b
). An agalacto-biantennary sugar chain labeled with pyridylaminobutylamine was used as an acceptor substrate. Cell homogenates were incubated at 37°C with 5 µM of the acceptor substrate and 0.5 mM GDP-fucose as a donor in 0.1 M MES-NaOH, 1% Triton X-100 (pH 7.0). The reactions were terminated by boiling after an appropriate reaction time, and the mixtures were centrifuged at 10,000 x g in a microcentrifuge for 10 min. The resulting supernatants were injected to a reversed phase HPLC equipped with TSKgel, ODS 80TM (4.6 x 150 mm). The product and the substrate were separated isocratically with 20 mM ammonium acetate buffer (pH 4.0) containing 0.15% n-butanol. Fluorescence of the column elute was detected with fluorescence detector (Shimazu, model RF-10AXL) at excitation and emission wavelengths of 320 nm and 400 nm, respectively.
Kinetic analysis and inhibition study with nucleotides
Kinetic analysis was carried out under essentially the same conditions as used above with the exception of the concentration of the substrates. When the kinetic parameters for GDP-fucose were assessed, the concentration of the fluorescence-labeled acceptor, 5 µM, was used with variable concentrations of the donor. For the determination of parameters for the acceptor substrate, the concentration of GDP-fucose was fixed at 0.5 mM. Apparent kinetic parameters for these substrates were obtained by double reciprocal plots. Ki values for GDP and GMP in competition with the donor substrate were determined in the activity assay using various concentrations of the donor and fixed concentration (5 µM) of the acceptor.
Protein determination
Protein content was determined according to the method of Bradford using bovine serum albumin as a standard (Bradford, 1976).
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Acknowledgments |
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Abbreviations |
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Footnotes |
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References |
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Aoyagi,Y., Isemura,M., Yoshizawa,Z., Suzuki,Y., Sekine,C., Ono,T. and Ichida,F. (1985) Fucosylation of serum alpha-fetoprotein in patients with primary hepatocellular carcinoma. Biochim. Biophys. Acta, 830, 217233.[ISI][Medline]
Aoyagi,Y., Suzuki,Y., Igarashi,A., Saitoh,M., Oguro,T., Yokota,S., Mori,T., Suda,T., Isemura,M. and Asakura,H. (1993a) Carbohydrate structures of human alpha-fetoprotein of patients with hepatocellular carcinoma: presence of fucosylated and non-fucosylated triantennary glycans. Br. J. Cancer, 67, 486492.[ISI][Medline]
Aoyagi,Y., Suzuki,Y., Igarashi,A., Yokota,S., Mori,T., Suda,T., Naitou,A., Isemura,M. and Asakura,H. (1993b) Highly enhanced fucosylation of -fetoprotein in patients with germ cell tumor. Cancer, 72, 615618.[ISI][Medline]
Boeggeman,E.E., Balaji,P.V. and Qasba,P.K. (1995) Functional domains of bovine beta-1,4 galactosyltransferase. Glycoconj. J., 12, 865878.[ISI][Medline]
Bradford,M.M. (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem., 72, 248254.[ISI][Medline]
Breton,C., Oriol,R. and Imberty,A. (1998) Conserved structural features in eukaryotic and prokaryotic fucosyltransferases. Glycobiology, 8, 8794.
Campion,B., Leger,D., Wieruszeski,J.M., Montreuil,J. and Spik,G. (1989) Presence of fucosylated triantennary, tetraantennary and pentaantennary glycans in transferrin synthesized by the human hepatocarcinoma cell line Hep G2. Eur. J. Biochem. 184, 405413.[Abstract]
Chan,C.L. and Gill,G.N. (1996) Mutational analysis of the nucleotide binding site of the epidermal growth factor receptor and v-Src protein-tyrosine kinases. J. Biol. Chem., 271, 2261922623.
Costache,M., Apoil,P.A., Cailleau,A., Elmgren,A., Larson,G., Henry,S., Blancher,A., Iordachescu,D., Oriol,R. and Mollicone,R. (1997) Evolution of fucosyltransferase genes in vertebrates. J. Biol. Chem., 272, 2972129728.
Felgner,P.L., Gadek,T.R., Holm,M., Roman,R., Chan,H.W., Wenz,M., Northrop,J.R., Ringold,G.M. and Danielsen,M. (1987) Lipofection: a highly efficient, lipid-mediated DNA-transfection procedure. Proc. Natl. Acad. Sci. USA, 84, 74137417.[Abstract]
Hutchinson,W.L., Du,M.Q., Johnson,P.J. and Williams,R. (1991) Fucosyltransferases: differential plasma and tissue alterations in hepatocellular carcinoma and cirrhosis. Hepatology, 13, 683688.[ISI][Medline]
Ikeda,Y., Fujii,J., Taniguchi,N. and Meister,A. (1995a) Human gamma-glutamyl transpeptidase mutants involving conserved aspartate residues and the unique cysteine residue of the light subunit. J. Biol. Chem., 270, 1247112475.
Ikeda,Y., Fujii,J., Taniguchi,N. and Meister,A. (1995b) Expression of an active glycosylated human gamma-glutamyl transpeptidase mutant that lacks a membrane anchor domain. Proc. Natl Acad. Sci. USA 92, 126130.[Abstract]
Ikeda,Y., Fujii,J. anderson,M.E., Taniguchi,N. and Meister,A. (1995c) Involvement of Ser-451 and Ser-452 in the catalysis of human gamma-glutamyl transpeptidase. J. Biol. Chem., 270, 2222322228.
Kazuta,Y., Tokunaga,E., Aramaki,E. and Kondo,H. (1998) Identification of lysine-238 of Escherichia coli biotin carboxylase as an ATP-binding residue. FEBS Lett., 427, 377380.[ISI][Medline]
Kunkel,T.A. (1985) Rapid and efficient site-specific mutagenesis without phenotypic selection. Proc. Natl. Acad. Sci. USA, 82, 488492.[Abstract]
Laemmli,U.K. (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature, 227, 680685.[ISI][Medline]
Li,W., Yu,J.C., Shin,D.Y. and Pierce,J.H. (1995) Characterization of a protein kinase C-delta (PKC-delta) ATP binding mutant. An inactive enzyme that competitively inhibits wild type PKC-delta enzymatic activity. J. Biol. Chem., 270, 83118318.
Longmore,G.D. and Schachter,H. (1982) Product-identification and substrate-specificity studies of the GDP-L-fucose:2-acetamido-2-deoxy-ß-D-glucoside (FUC goes to Asn-linked GlcNAc) 6--L-fucosyltransferase in a Golgi-rich fraction from porcine liver. Carbohydr. Res., 100, 365392.[ISI][Medline]
Mergaert,P., DHaeze,W., Fernandez, Lopez,M., Geelen,D., Goethals,K., Prome,J.C., Van-Montagu,M. and Holsters,M. (1996) Fucosylation and arabinosylation of Nod factors in Azorhizobium caulinodans: involvement of nolK, nodZ as well as noeC and/or downstream genes. Mol. Microbiol., 21, 409419.[ISI][Medline]
Miyoshi,E., Uozumi,N., Noda,K., Hayashi,N., Hori,M., Taniguchi,N. Expression of 1-6 fucosyltransferase in rat tissues and human cancer cell lines. (1997) Int. J. Cancer, 72, 11171121.[ISI][Medline]
Murray,B.W., Takayama,S., Schultz,J. and Wong,C.H. (1996) Mechanism and specificity of human -1,3-fucosyltransferase V. Biochemistry, 35, 1118311195.[ISI][Medline]
Murray,B.W., Wittmann,V., Burkart,M.D., Hung,S.C. and Wong,C.H. (1997) Mechanism of human -1,3-fucosyltransferase V: glycosidic cleavage occurs prior to nucleophilic attack. Biochemistry 36, 823831.[ISI][Medline]
Nguyen,A.T., Holmes,E.H., Whitaker,J.M., Ho,S., Shetterly,S. and Macher,B.A. (1998) Human 1,3/4-fucosyltransferases. I. Identification of amino acids involved in acceptor substrate binding by site-directed mutagenesis. J. Biol. Chem., 273, 2524425249.
Noda,K., Miyoshi,E., Uozumi,N., Gao, CX., Suzuki,K., Hayashi,N., Hori,M., Taniguchi,N. (1998b) High expression of -16 fucosyltransferase during rat hepatocarcinogenesis. Int. J. Cancer, 75, 444450.[ISI][Medline]
Noda,K., Miyoshi,E., Uozumi,N., Yanagidani,S., Ikeda,Y., Gao,C., Suzuki,K., Yoshihara,H., Yoshikawa,M., Kawano,K., Hayashi,N., Hori,M. and Taniguchi,N. (1998a) Gene expression of alpha1-6 fucosyltransferase in human hepatoma tissues: a possible implication for increased fucosylation of -fetoprotein. Hepatology, 28, 944952.[ISI][Medline]
Ohno,M., Nishikawa,A., Kouketsu,M., Taga,H., Endo,Y., Hada,T., Higashino,K. and Taniguchi,N. (1992) Enzymatic basis of sugar structures of -fetoprotein in hepatoma and hepatoblastoma cell lines: correlation with activities of
16 fucosyltransferase and N-acetylglucosaminyltransferases III and V. Int. J. Cancer, 51, 315317.[ISI][Medline]
Piwnica-Worms,H. (1987) In Ausubel,F.M., Brent,R.E., Moore,D.D., Seidman,J.G., Smith,J.A. and Struhl,K. (eds.), Current Protocols in Molecular Biology. Greene Publishing Associates and Wiley-Interscience, New York, pp. 16.8.116.11.7.
Powell,J.T. and Brew,K. (1976a) Affinity labeling of bovine colostrum galactosyltransferase with a uridine 5'-diphosphate derivative. Biochemistry, 15, 34993505.[ISI][Medline]
Powell,J.T. and Brew,K. (1976b) Metal ion activation of galactosyltransferase. J. Biol. Chem., 251, 36453652.[Abstract]
Schachter,H. (1986) Biosynthetic controls that determine the branching and microheterogeneity of protein-bound oligosaccharides. Biochem. Cell Biol.., 64, 163181.[ISI][Medline]
Shen,J.B., Orozco,E.M. Jr. and Ogren,W.L. (1991) Expression of the two isoforms of spinach ribulose 1,5-bisphosphate carboxylase activase and essentiality of the conserved lysine in the consensus nucleotide-binding domain. J. Biol. Chem., 266, 89638968.
Sherwood,A.L., Nguyen,A.T., Whitaker,J.M., Macher,B.A., Stroud,M.R. and Holmes,E.H. (1998) Human 1,3/4-fucosyltransferases. III. A Lys/Arg residue located within the
1,3-FucT motif is required for activity but not substrate binding. J. Biol. Chem., 273, 2525625260.
Stacey,G., Luka,S., Sanjuan,J., Banfalvi,Z., Nieuwkoop,A.J., Chun,J.Y., Forsberg,L.S. and Carlson,R. (1994) nodZ, a unique host-specific nodulation gene, is involved in the fucosylation of the lipooligosaccharide nodulation signal of Bradyrhizobium japonicum. J. Bacteriol., 176, 620633.[Abstract]
Tohgo,A., Munakata,H., Takasawa,S., Nata,K., Akiyama,T., Hayashi,N. and Okamoto,H. (1997) Lysine 129 of CD38 (ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase) participates in the binding of ATP to inhibit the cyclic ADP-ribose hydrolase. J. Biol. Chem., 272, 38793882.
Uozumi,N., Yanagidani,S., Miyoshi,E., Ihara,Y., Sakuma,T., Gao,C.X., Teshima,T., Fujii,S., Shiba,T. and Taniguchi,N. (1996a) Purification and cDNA cloning of porcine brain GDP-L-Fuc:N-acetyl-ß-D-glucosaminide 1
6fucosyltransferase. J. Biol. Chem., 271, 2781027817.
Uozumi,N., Teshima,T., Yamamoto,T., Nishikawa,A., Gao,Y.E., Miyoshi,E., Gao,C.X., Noda,K., Islam,K.N., Ihara,Y., Fujii,S., Shiba,T. and Taniguchi,N. (1996b) A fluorescent assay method for GDP-L-Fuc:N-acetyl-ß-D-glucosaminide 16fucosyltransferase activity, involving high performance liquid chromatography. J. Biochem., 120, 385392.[Abstract]
Vo,L., Lee,S., Marcinko,M.C., Holmes,E.H. and Macher,B.A. (1998) Human 1,3/4-fucosyltransferases. II. A single amino acid at the COOH terminus of FucT III and V alters their kinetic properties. J. Biol. Chem., 273, 2525025255.
Voynow,J.A., Kaiser,R.S., Scanlin,T.F. and Glick,M.C. (1991) Purification and characterization of GDP-L-fucose-N-acetyl beta-D-glucosaminide 1-6fucosyltransferase from cultured human skin fibroblasts. Requirement of a specific biantennary oligosaccharide as substrate. J. Biol. Chem., 266, 2157272157.
Wilson,J.R., Williams,D. and Schachter,H. (1976) The control of glycoprotein synthesis: N-acetylglucosamine linkage to a mannose residue as a signal for the attachment of L-fucose to the asparagine-linked N-acetylglucosamine residue of glycopeptide from 1-acid glycoprotein. Biochem. Biophys. Res. Commun., 72, 909916.[ISI][Medline]
Yamaguchi,Y., Fujii,J., Inoue,S., Uozumi,N., Yanagidani,S., Ikeda,Y., Egashira,M., Miyoshi,O., Niikawa,N. and Taniguchi,N. (1999) Mapping of the -1,6-fucosyltransferase gene, FUT8, to human chromosome 14q24.3. Cytogenet. Cell Genet., 84, 5860.[ISI][Medline]
Yamashita,K., Koide. N., Endo. T., Iwaki. Y. and Kobata. A. (1989) Altered glycosylation of serum transferrin of patients with hepatocellular carcinoma. J. Biol. Chem. 264, 24152423.
Yanagidani,S., Uozumi,N., Ihara,Y., Miyoshi,E., Yamaguchi,N. and Taniguchi,N. (1997) Purification and cDNA cloning of GDP-L-Fuc:N-acetyl-ß-D-glucosaminide:1-6 fucosyltransferase (
1-6 FucT) from human gastric cancer MKN45 cells. J. Biochem., 121, 626632.[Abstract]