Publications

• Identification and expression of a sialyltransferase responsible for the synthesis of disialylgalactosylgloboside in normal and malignant kidney cells: downregulation of ST6GalNAc VI in renal cancers.

  Senda M., Ito A., Tsuchida A., Hagiwara T., Kaneda T., Nakamura Y., Kasama K., Kiso M., Yoshikawa K., Katagiri Y., Ono Y., Ogiso M., Urano T., Furukawa K., Oshima S., Furukawa K.

  Although disialyl glycosphingolipids such as GD3 and GD2 have been considered to be associated with malignant tumours, whether branched-type disialyl glycosphingolipids show such an association is not well understood. We investigated the sialyltransferases responsible for the biosynthesis of DSGG ... >> More

  Although disialyl glycosphingolipids such as GD3 and GD2 have been considered to be associated with malignant tumours, whether branched-type disialyl glycosphingolipids show such an association is not well understood. We investigated the sialyltransferases responsible for the biosynthesis of DSGG (disialylgalactosylgloboside) from MSGG (monosialylgalactosylgloboside). Among six GalNAc:alpha2,6-sialyltransferases cloned to date, we focused on ST6GalNAc III, V and VI, which utilize sialylglycolipids as substrates. In vitro enzyme analyses revealed that ST6GalNAc III and VI generated DSGG from MSGG with V(max)/K(m) values of 1.91 and 4.16 respectively. Transfection of the cDNA expression vectors for these enzymes resulted in DSGG expression in a renal cancer cell line. Although both ST6GalNAc III and VI genes were expressed in normal kidney cells, the expression profiles of ST6GalNAc VI among 20 renal cancer cell lines correlated clearly with those of DSGG, suggesting that the sialyltransferase involved in the synthesis of DSGG in the kidney is ST6GalNAc-VI. ST6GalNAc-VI and DSGG were found in proximal tubule epithelial cells in normal kidney tissues, while they were downregulated in renal cancer cell lines and cancer tissues. All these findings indicated that DSGG was suppressed during the malignant transformation of the proximal tubules as a maturation arrest of glycosylation. << Less

  Biochem. J. 402:459-470(2007) [PubMed] [EuropePMC]

  This publication is cited by 7 other entries.

• Molecular cloning and expression of mouse GD1alpha/GT1aalpha/GQ1balpha synthase (ST6GalNAc VI) gene.

  Okajima T., Chen H.-H., Ito H., Kiso M., Tai T., Furukawa K., Urano T., Furukawa K.

  A novel member of the mouse CMP-NeuAc:beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc VI, was identified by BLAST analysis of expressed sequence tags. The sequence of the cDNA clone of ST6GalNAc VI encoded a type II membrane protein with 43 amino ... >> More

  A novel member of the mouse CMP-NeuAc:beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc VI, was identified by BLAST analysis of expressed sequence tags. The sequence of the cDNA clone of ST6GalNAc VI encoded a type II membrane protein with 43 amino acids composing the cytoplasmic domain, 21 amino acids composing the transmembrane region, and 269 amino acids composing the catalytic domain. The predicted amino acid sequence showed homology to the previously cloned ST6GalNAc III, IV, and V, with common amino acid sequences in sialyl motif L and S among these four enzymes. A fusion protein with protein A and extracts from L cells transfected with ST6GalNAc VI in an expression vector showed enzyme activity of alpha2,6-sialyltransferase for GM1b, GT1b, and GD1a but not toward glycoproteins. Thin layer chromatography-immunostaining revealed that the products were GD1alpha, GQ1balpha, and GT1aalpha. Northern blotting revealed that this gene was expressed in a wide range of mouse tissues such as colon, liver, heart, spleen, and brain. It is concluded that this enzyme is a novel sialyltransferase involved in the synthesis of alpha-series gangliosides in the nervous tissues and many other tissues. << Less

  J. Biol. Chem. 275:6717-6723(2000) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.

• Synthesis of disialyl Lewis a (Le(a)) structure in colon cancer cell lines by a sialyltransferase, ST6GalNAc VI, responsible for the synthesis of alpha-series gangliosides.

  Tsuchida A., Okajima T., Furukawa K., Ando T., Ishida H., Yoshida A., Nakamura Y., Kannagi R., Kiso M., Furukawa K.

  Biosynthesis of disialyl Lewis a (Lea) was analyzed using previously cloned ST6GalNAc V and ST6GalNAc VI, which were responsible for the synthesis of alpha-series gangliosides. Among lactotetraosylceramide (Lc4), neolactotetraosylceramide, and their sialyl forms, only sialyl Lc4 was sialylated wit ... >> More

  Biosynthesis of disialyl Lewis a (Lea) was analyzed using previously cloned ST6GalNAc V and ST6GalNAc VI, which were responsible for the synthesis of alpha-series gangliosides. Among lactotetraosylceramide (Lc4), neolactotetraosylceramide, and their sialyl forms, only sialyl Lc4 was sialylated with ST6GalNAc V and ST6GalNAc VI. The products were confirmed to be disialyl Lea in TLC-immunostaining. Compared with the original substrate GM1b, the synthetic rates of disialyl Lea were 22 and 38% with ST6GalNAc V and ST6GalNAc VI, respectively. Since sialyl Lea could not be converted to disialyl Lea, disialyl Lea was produced only from disialyl Lc4. Therefore, it appears that ST6GalNAc V/VI and fucosyltransferase III (FUT-3) compete for sialyl Lc4, their common substrate. The results of either one transfection or co-transfection of two genes into COS1 cells revealed that both ST6GalNAc VI and FUT-3 contributed in the synthesis of disialyl Lea but partly compete with each other. Many colon cancer cell lines expressed the ST6GalNAc VI gene more or less, and some of them actually expressed disialyl Lea. None of them expressed ST6GalNAc V. These results suggested the novel substrate specificity of ST6GalNAc VI, which is responsible for the synthesis of disialyl Lea but not for alpha-series gangliosides in human colon tissues. << Less

  J. Biol. Chem. 278:22787-22794(2003) [PubMed] [EuropePMC]

  This publication is cited by 4 other entries.

• Molecular cloning and functional expression of two members of mouse NeuAc-alpha-2,3Gal-beta-1,3GalNAc GalNAc-alpha2,6-sialyltransferase family, ST6GalNAc III and IV.

  Lee Y.-C., Kaufman M., Kitazume-Kawaguchi S., Kono M., Takashima S., Kurosawa N., Liu H., Pircher H., Tsuji S.

  Two cDNA clones encoding NeuAcalpha2,3Galbeta1,3GalNAc GalNAcalpha2, 6-sialyltransferase have been isolated from mouse brain cDNA libraries. One of the cDNA clones is a homologue of previously reported rat ST6GalNAc III according to the amino acid sequence identity (94.4%) and the substrate specif ... >> More

  Two cDNA clones encoding NeuAcalpha2,3Galbeta1,3GalNAc GalNAcalpha2, 6-sialyltransferase have been isolated from mouse brain cDNA libraries. One of the cDNA clones is a homologue of previously reported rat ST6GalNAc III according to the amino acid sequence identity (94.4%) and the substrate specificity of the expressed recombinant enzyme, while the other cDNA clone includes an open reading frame coding for 302 amino acids. The deduced amino acid sequence is not identical to those of other cloned mouse sialyltransferases, although it shows the highest sequence similarity with mouse ST6GalNAc III (43.0%). The expressed soluble recombinant enzyme exhibited activity toward NeuAcalpha2, 3Galbeta1, 3GalNAc, fetuin, and GM1b, while no significant activity was detected toward Galbeta1,3GalNAc or asialofetuin, or the other glycoprotein substrates tested. The sialidase sensitivity of the 14C-sialylated residue of fetuin, which was sialylated by this enzyme with CMP-[14C]NeuAc, was the same as that of ST6GalNAc III. These results indicate that the expressed enzyme is a new type of GalNAcalpha2,6-sialyltransferase, which requires sialic acid residues linked to Galbeta1,3GalNAc residues for its activity; therefore, we designated it mouse ST6GalNAc IV. Although the substrate specificity of this enzyme is similar to that of ST6GalNAc III, ST6GalNAc IV prefers O-glycans to glycolipids. Glycolipids, however, are better substrates for ST6GalNAc III. << Less

  J. Biol. Chem. 274:11958-11967(1999) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.

• Molecular cloning of brain specific GD1alpha synthase (ST6GalNAc V) containing CAG/glutamine repeats.

  Okajima T., Fukumoto S., Ito H., Kiso M., Hirabayashi Y., Urano T., Furukawa K.

  A novel member of the mouse CMP-NeuAc: beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc V, was identified by BLAST analysis of expressed sequence tags. The sequence of the longest cDNA clone of ST6GalNAc V encoded a type II membrane protein with 8 ... >> More

  A novel member of the mouse CMP-NeuAc: beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc V, was identified by BLAST analysis of expressed sequence tags. The sequence of the longest cDNA clone of ST6GalNAc V encoded a type II membrane protein with 8 amino acids comprising the cytoplasmic domain, 21 amino acids comprising the transmembrane region, and 306 amino acids comprising the catalytic domain. The predicted amino acid sequence showed homology to the previously cloned ST6GalNAc III and IV, with common amino acid sequences in sialyl motifs L and S among these three enzymes. Eleven CAG repeats were found in the stem region. A fusion protein with protein A and extracts from L cells transfected with ST6GalNAc V in a expression vector showed enzyme activity of alpha2,6-sialyltransferase almost exclusively for GM1b, but not toward glycoproteins. Sialidase treatment and thin layer chromatography immunostaining revealed that the product was GD1alpha. Northern blotting revealed that three transcripts of the gene were expressed specifically in brain tissues. It is concluded that this enzyme is involved in the synthesis of GD1alpha in the nervous tissues, and the CAG repeats may have implications in neurodegenerative diseases. << Less

  J. Biol. Chem. 274:30557-30562(1999) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• A novel glycosyltransferase with a polyglutamine repeat; a new candidate for GD1alpha synthase (ST6GalNAc V).

  Ikehara Y., Shimizu N., Kono M., Nishihara S., Nakanishi H., Kitamura T., Narimatsu H., Tsuji S., Tatematsu M.

  The fifth type GalNAcalpha2,6-sialyltransferase (mST6GalNAc V) was cloned from a mouse brain cDNA library. mST6GalNAc V exhibited type II transmembrane topology containing a polyglutamine repeat, which showed 42.6% and 44.8% identity to mouse ST6GalNAc III and IV, respectively. Northern blot analy ... >> More

  The fifth type GalNAcalpha2,6-sialyltransferase (mST6GalNAc V) was cloned from a mouse brain cDNA library. mST6GalNAc V exhibited type II transmembrane topology containing a polyglutamine repeat, which showed 42.6% and 44.8% identity to mouse ST6GalNAc III and IV, respectively. Northern blot analysis revealed that the mST6GalNAc V gene was specifically expressed in forebrain and cerebellum. mST6GalNAc V exhibited GD1alpha synthetic activity from GM1b the same as mST6GalNAc III and IV. The activity ratio of GM1b toward fetuin and the expression pattern were completely different among the three ST6GalNAcs. Interestingly, the polyglutamine repeat number was different from that of inbred mice. We report the first glycosyltransferase with a polymorphic polyglutamine repeat. << Less

  FEBS Lett. 463:92-96(1999) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.

• Molecular cloning and expression of human ST6GalNAc III: restricted tissue distribution and substrate specificity.

  Tsuchida A., Ogiso M., Nakamura Y., Kiso M., Furukawa K., Furukawa K.

  We isolated human ST6GalNAc III cDNA clones. The typical cDNA clones predicted a type II membrane protein of 305 amino acids with a short cytoplasmic transmembrane domain of sixteen amino acids and a catalytic domain of 280 amino acids. A short form clone predicted a protein of 240 amino acids lac ... >> More

  We isolated human ST6GalNAc III cDNA clones. The typical cDNA clones predicted a type II membrane protein of 305 amino acids with a short cytoplasmic transmembrane domain of sixteen amino acids and a catalytic domain of 280 amino acids. A short form clone predicted a protein of 240 amino acids lacking 65 amino acids including the transmembrane portion. The alternative usage of the second exon seemed to generate these two transcripts. Both had two common regions found among sialyltransferases cloned so far, i.e. sialyl motif L and sialyl motif S. Alignments of human, mouse and rat orthologs indicated that high homologies, i.e. 85-95% identity among these species at amino acid levels. We analyzed the expression pattern and substrate specificity of the product, demonstrating a very restricted expression pattern and a high substrate specificity. Northern blotting revealed that hST6GalNAc III is expressed in kidney and brain as a single band at 3.2 kb. In enzyme assay of the long form, the transfer of sialic acid onto alpha2,3-sialylated acceptor substrates, i.e. GM1b and sialyl lactotetraosylceramide, was observed. hST6GalNAc III also showed sialyltransferase activity toward O-glycans (but not N-glycans) in fetuin. << Less

  J. Biochem. 138:237-243(2005) [PubMed] [EuropePMC]

  This publication is cited by 4 other entries.

• Molecular cloning of a developmentally regulated N-acetylgalactosamine alpha2,6-sialyltransferase specific for sialylated glycoconjugates.

  Sjoberg E.R., Kitagawa H., Glushka J., van Halbeek H., Paulson J.C.

  A cDNA encoding a novel sialyltransferase has been isolated employing the polymerase chain reaction using degenerate primers to conserved regions of the sialylmotif that is present in all eukaryotic members of the sialyltransferase gene family examined to date. The cDNA sequence revealed an open r ... >> More

  A cDNA encoding a novel sialyltransferase has been isolated employing the polymerase chain reaction using degenerate primers to conserved regions of the sialylmotif that is present in all eukaryotic members of the sialyltransferase gene family examined to date. The cDNA sequence revealed an open reading frame coding for 305 amino acids, making it the shortest sialyltransferase cloned to date. This open reading frame predicts all the characteristic structural features of other sialyltransferases including a type II membrane protein topology and both sialylmotifs, one centrally located and the second in the carboxyl-terminal portion of the cDNA. When compared with all other sialyltransferase cDNAs, the predicted amino acid sequence displays the lowest homology in the sialyltransferase gene family. Northern analysis shows this sialyltransferase to be developmentally regulated in brain with expression persisting through adulthood in spleen, kidney, and lung. Stable transfection of the full-length cDNA in the human kidney carcinoma cell line 293 produced an active sialyltransferase with marked specificity for the sialoside, Neu5Ac-alpha2,3Gal-beta1,3GalNAc and glycoconjugates carrying the same sequence such as G(M1b) and fetuin. The disialylated tetrasaccharide formed by reacting the sialyltransferase with the aforementioned sialoside was analyzed by one- and two-dimensional 1H and 13C NMR spectroscopy and was shown to be the Neu5Ac-alpha2,3Gal-beta1,3(Neu5Ac-alpha2,6)GalNAc sialoside. This indicates that the enzyme is a GalNAc alpha-2,6-sialyltransferase. Since two other ST6GalNAc sialyltransferase cDNAs have been isolated, this sialyltransferase has been designated ST6GalNAc III. Of these three, ST6GalNAc III displays the most restricted acceptor specificity and is the only sialyltransferase cloned to date capable of forming the developmentally regulated ganglioside G(D1alpha) from G(M1b). << Less

  J. Biol. Chem. 271:7450-7459(1996) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.