ST6Gal I
Author: Arun K. Datta
Reviewers: Karen J. Colley, Joseph T Y. Lau
PROW 2:23-31(2001)

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OVERVIEW Summary Sentence

• ST6Gal I is a sialyltransferase that transfers sialic acid (Sia) from CMP-Sia to C6 position of terminal galactose forming SiaAlpha2,6Galb1,4GlcNAc-sequence common to many Asparagine(N)-linked oligosaccharides

Abstract

• ST6Gal I is an enzyme belonging to the sialyltransferase family {Tsuji_S/Paulson_JC.1996.GLYCO} and forms SiaAlpha2,6Gal linkage on the GlaBeta1,4GlcNAc-sequence present on N-linked glycoproteins. So far, 16 enzymes have been cloned {Tsuji_S.1996.JBT} ; {Lee_YC/Tsuji_S.1999.JBC} ; {Okajima_T/Furukawa_K.1999.JBC} , each of which exhibits unique specificity for its acceptor substrates and forms one of four sialic acid linkages, namely, Neu5Aca2,6Gal, Neu5Aca2,3Gal, Neu5Aca2,6GalNAc, or Neu5Aca2,8Neu5Ac. ST6Gal I forms Neu5Aca2,6Gal linkage. This and other sialyltransferases are localized in the Golgi apparatus {Taatjes_DJ/Shaper_JH.1987.EJCB} and are type II membrane proteins with a short cytoplasmic domain, an N-terminal signal anchor, a "stem" region, and a large luminal domain that confers the catalytic activity. Another structural feature of ST6Gal I that is common among other sialyltransferases despite little homology is the presence of two conserved protein domains, termed, L-(Long) and S-(Short) sialylmotif {Datta_AK/Paulson_JC.1997.IJBB} *. Analysis by site-directed mutagenesis showed that these two motifs are linked by an essential disulfide linkage and important for substrate binding {Datta_AK/Paulson_JC.1995.JBC} ; {Datta_AK/Paulson_JC.1998.JBC} ; {Datta_AK/Paulson_JC.2001.JBC} . In addition, a very small motif of unknown function is found at the C-terminal {Geremia_RA/Delannoy_P.1997.GLYCO} . No structural information, however, is available from X-ray crystallography or NMR studies. The product of this ST6Gal I, Neu5Aca2,6Galb1,4GlcNAc is shown to be the ligand of CD22 , a receptor present on B cells {Powell_LD/Varki_A.1994.JBC} . In vivo functional study using ST6Gal I deficient mice indicated that this sialoside is essential in promoting B lymphocyte activation and immune function {Hennet_T/Marth_JD.1998.PNASU}

Molecular Families

• Families in which hST6gal 1 is a member
  • hST6gal 1-->sialyltransferase -->glycosyltransferase

Names

• SIAT1 [HUGO gene name]
• hST6gal 1 (STgal 1 , ST6gal 1 ) [For nomenclature, {Tsuji_S/Paulson_JC.1996.GLYCO} ]
• sialyltransferase 1
• beta-galactoside alpha-2,6-sialytransferase (CMP-N-acetylneuraminate beta-galactoside alpha-2,6-sialytransferase )
• EC 2.4.99.1 [ 2.4.99.1 ]

Major Links

• LocusLink: 6480
• Mendelian Inheritance in Man (OMIM): 109675
• SwissProt annotated protein record: P15907

Author's Additional Insights

• No information

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SYSTEM VIEW Disease Relevance / Function in Vivo

• ST6Gal I deficient mice showed symptoms of immunosuppression {Hennet_T/Marth_JD.1998.PNASU}
  • The symptoms were marked with reduced serum IgM levels with attenuated antibody production to T-independent and T-dependent antigens
  • The absence of the enzyme product did not effect B cell development, however these mice showed impaired B cell proliferation in response to IgM or CD40 crosslinking
  • The deficiency caused an alteration in phosphotyrosine accumulation following cross-linking of the B lymphocyte antigen receptor

Cellular Function

• ST6Gal I is localized in trans Golgi and trans Golgi network in which it acts to add sialic acid to the oligosaccharide chains of the newly synthesized protein while in transit through Golgi {Roth_J/Paulson_JC.1985.CELL} ; {Taatjes_DJ/Roth_J.1986.EJCB}
• The dimeric form of this enzyme is inactive and may act as galactose-specific lectin {Ma_J/Colley_KJ.1996.JBC}
• The enzyme product Sia6LacNAc is a ligand of CD22 , a receptor on B cell and shown to be essential in regulating B lymphocyte activation and immune function {Hennet_T/Marth_JD.1998.PNASU}
• NeuAc6LacNAc also plays a role in the expression of the biological activity of prolactin/growth hormone family members during rat pregnancy {Manzella_SM/Baenziger_JU.1997.JBC}

Protein Location

• ST6Gal I is localized in trans Golgi and trans Golgi network {Roth_J/Paulson_JC.1985.CELL}
• Proteolytically cleaved yet active enzyme is also found in body fluids such as colostrum, breast milk, blood, lymph, and semen {Hudgin_RL/Schachter_H.1971.CJB} ; {Bartholomew_BA/Roseman_S.1973.JBC} ; {Ratnam_S/Mookerjea_S.1981.BBA} ; {Daunter_B/Newlands_J.1981.ANDRO}

Cellular Expression

• ST6Gal I is a transmembrane protein with C-terminal catalytic domain residing in the Golgi lumen
• Low to high expression in heart, brain, placenta, liver, lung, skeletal muscle, kidney, spleen, thymus, prostate, ovary, small intestine, and colon {Kitagawa_H/Paulson_JC.1994.JBC}
  • liver has the highest expression
• Peripheral blood leukocyte
• Variable expression in HL-60 promyelocytic leukemia cell line and Burkitt's lymphoma B cell line (Daudi)
• High expression in mammary glands during late pregnancy and lactation {Dalziel_M/Lau_JTY.2001.GLYCO}
• Low to high expression during activation of resting B lymphocytes {A_Wuensch_S/T_Y_Lau_J.2000.GLYCO} **
• NOTE: ** in this section indicates added by reviewer JT Lau

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GENE Gene Sequence Links

• GenBank Accession Code: U27580 [liver-specific transcriptional promoter region and exon 1 {Wang_X/Lau_JT.1993.JBC} ], U27570 [promoter and exon 1, partial sequence {Wang_X/Lau_JT.1993.JBC} ]

Chromosomal Location

• 16 [mouse] [{Kalcheva_I/Lau_JT.1997.MG} ; Review in this section contributed by JT Lau]
• 3q21-q28 [human]

Gene Polymorphism

• No information

Transcription Regulating Molecules

Transcription_Factor	Comment
Promoter P1	Promoter P1 controls ST6Gal I expression in liver and intestinal epithelium {Wang_X/Lau_JT.1993.JBC} ; {Vertino-Bell_A/Lau_JT.1994.DB} . P1 activity is modulated by liver-enriched transcription factors HNF-1, DBP, and LAP {Svensson_EC/Paulson_JC.1992.JBC} as well as by glucocorticoid {Wang_XC/Lau_JT.1989.JBC}
Promoter P2	Promoter P2 region containing AP2, NF-kB, and TATA transcriptional start sites controls ST6Gal I expression in mature B cells {Lo_NW/Lau_JT.1996.BBRC}
Promoter P3	Promoter P3 was shown to control expression of hST6Gal I gene during HL-60 differentiation. The activity is modulated by Sp-1 and Oct-1 {Taniguchi_A/Matsumoto_K.2000.GLYCO}

Gene Annotation

• No information

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TRANSCRIPT Transcript Sequence Links

• GenBank Accession Code: X17247 [complete cDNA {Grundmann_U/Zettlmeissl_G.1990.NAR} ], U67847 [exon U {Lo_NW/Lau_JT.1996.GLYCO} ], U67848 [exon V {Lo_NW/Lau_JT.1996.GLYCO} ]

Post-transcriptional Modification

• The hST6Gal I gene comprises 7-8 exons of which 5 are coding exons {Wang_X/Lau_JT.1993.JBC}
• Multiple transcripts differing only in the 5'-untranslated region {Aasheim_HC/Smeland_EB.1993.EJB} ; {Wang_X/Lau_JT.1993.JBC} ; {Lo_NW/Lau_JT.1996.BBRC} ; {Lo_NW/Lau_JT.1996.GLYCO}
• Exon X, Y and Z are absent in liver
• Exon Y and Z are present in number of cells and tissues expressing ST6Gal mRNA
• Additional mRNA forms utilizing unique exons for the 5’-untranslated region documented in mouse {A_Wuensch_S/T_Y_Lau_J.2000.GLYCO} ; {Dalziel_M/Lau_JTY.2001.GLYCO} **
• NOTE: ** in this section indicates added by reviewer JT L

Transcript Annotation

• ST6Gal I expression is induced by:
  • cytokines {Hanasaki_K/Bevilacqua_MP.1994.JBC} ; {Dalziel_M/Lau_JT.1999.GLYCO}
  • n-butyrate {Shah_S/Baumann_H.1992.JBC}
  • glucocorticoids {Wang_XC/Lau_JT.1990.JBC}
  • dexamethasone {Wang_XC/Lau_JT.1989.JBC} ; {Wang_XC/Lau_JT.1990.JBC}
  • phorbol ester {Li_M/Lance_P.1998.AJP}

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PROTEIN Biochemical Activity

• ST6Gal I transfers sialic acid from CMP-NeuAc to GalBeta1,4GlcNAc on N-linked glycoproteins yielding NeuAcAlpha2-6 GalBeta1,4GlcNAc; in vitro, it can also transfers sialic acid to LacNAc and LacdiNAc {Nemansky_M/Van_den_Eijnden_DH.1992.BJ}
• ST6Gal I can transfer other forms of sialic acid although Neu5Ac is believed to be the precursor of all other varieties known {Varki_A.1992.GLYCO}
• Optimal pH for this enzyme is 6.0-6.5

Protein Sequence Links

• SwissProt annotated protein record: P15907

Protein Sequence Annotation

• Total protein 406 aa
  • cytoplasmic region: 1-9 aa
  • signal-anchor region: 10-26 aa
  • stem region: 27-96 aa {Chen_C/Colley_KJ.2000.GLYCO} *
  • catalytic domain: 97-403 aa*
  • N-linked glycosylation sites: 149 aa and 161 aa

Protein Polymorphism

• Two natural forms exist with Tyr or Cys at amino acid 123. These two forms differ in their proteolytic processing and cellular trafficking {Ma_J/Colley_KJ.1997.JBC} *

Protein Physical Properties

• Membrane bound enzyme has a molecular weight of 47 kDa {Roth_J/Paulson_JC.1985.CELL} , whereas the proteolytic released active enzyme is 37-43 kDa {Weinstein_J/Paulson_JC.1982.JBC}
• Membrane bound enzyme may also form inactive dimer and can act as galactose binding lectin {Ma_J/Colley_KJ.1996.JBC}
• The active monomer contains an intramolecular disulfide bond formed by two conserved Cys present in the large and small sialyl motifs {Datta_AK/Paulson_JC.2001.JBC} *

Post-translational Modification

• Two potential N-linked glycosylation sites at aa. 149 and 161 (aa 146 and 158 for rat) which were shown to be modified and important for activity and trafficking of the soluble rat enzyme but not the membrane-bound rat enzyme {Fast_DG/McCaffrey_G.1993.BBA} ; {Chen_C/Colley_KJ.2000.GLYCO} *
• Modification by phosphorylation has also been reported {Ma_J/Colley_KJ.1999.JBC}

Protein Structure Links

• No information

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MOLECULAR INTERACTIONS Molecular Pathways

• Glycosylation

Enzymes for which this is a Substrate

• No information in table

Substrates

Substrate	Comment
Terminal GalBeta1,4GlcNAc containing N-linked glycoproteins	Terminal GalBeta1,4GlcNAc containing N-linked glycoproteins, such as, prolactin {Manzella_SM/Baenziger_JU.1997.JBC}
lactoferrin	{Coddeville_B/Spik_G.1992.CR}
fat globule membrane CD36	{Nakata_N/Kobata_A.1993.BIOCH}
HB-6	{Bast_BJ/Tedder_TF.1992.JCB}
CD75s (formerly CDw75 and CDw76)	{Bast_BJ/Tedder_TF.1992.JCB}
Various milk oligosaccharides	{Gyorgy_P/Zilliken_F.1974.EJB}

Other Ligands and Associated Molecules

• No information in table

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REAGENTS Model Animal Strains

Species_or_Strain	Supplier	Comment
Homozygous ST6Gal deficient female mice	Dr. Jamey D. Marth Howard Hughes Medical Institute San Diego, CA	Homozygous ST6Gal I deficient female mice in C57BL/6 background {Hennet_T/Marth_JD.1998.PNASU}

Monoclonal Antibodies

• No information in table

Polyclonal Antibodies

• Not commercially available. However, a limited quantity of serum may be obtained from Dr. Karen Colley (University of Illinois, Chicago) or Dr. James C. Paulson (The Scripps Research Institute, La Jolla, CA). ST6Gal I is expressed in most cells at very low levels and is frequently undetectable using these polyclonal antibodies. These do work well to recognize the enzyme expressed at higher levels in transfected cells or in FTO2B and H-4-II-E rat hepatoma cells. Limited quantities are available for non-commerical use*

Drugs and Small Molecules

• No information in table

Genetic Constructs

• No information in table

Purified Protein

• Not commercially available

Reagents Misc.

Reagent	Supplier	Comment
alpha2,6-(N)-sialyltransferase, from rat liver	Calbiochem ( 566217 )
alpha2,6-(N)-sialyltransferase, rat, recombinant, Spodoptera frugiperda	Calbiochem ( 566222 )
Sialyltransferase	Sigma ( S2769 )

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REFERENCES References

REVIEWS
1. {Datta_AK/Paulson_JC.1997.IJBB}
Datta AK, Paulson JC. 1997. Sialylmotifs of sialyltransferases. Indian J Biochem Biophys 34:157-165
2. {Harduin-Lepers_A/Delannoy_P.1995.GLYCO}
Harduin-Lepers A, Recchi MA, Delannoy P. 1995. 1994, the year of sialyltransferases. Glycobiology 5:741-758
3. {Paulson_JC/Colley_KJ.1989.JBC}
Paulson JC, Colley KJ. 1989. Glycosyltransferases. Structure, localization, and control of cell type-specific glycosylation. J Biol Chem 264:17615-17618
4. {Roth_J.1991.JEMT}
Roth J. 1991. Localization of glycosylation sites in the Golgi apparatus using immunolabeling and cytochemistry. J Electron Microsc Tech 17:121-131
5. {Tsuji_S.1996.JBT}
Tsuji S. 1996. Molecular cloning and functional analysis of sialyltransferases. J Biochem 120:1-13

PRIMARY CITATIONS
6. {A_Wuensch_S/T_Y_Lau_J.2000.GLYCO}
A Wuensch S, Huang RY, Ewing J, Liang X, T Y Lau J. 2000. Murine B cell differentiation is accompanied by programmed expression of multiple novel beta-galactoside alpha2, 6-sialyltransferase mRNA forms. Glycobiology 10:67-75
7. {Aasheim_HC/Smeland_EB.1993.EJB}
Aasheim HC, Aas-Eng DA, Deggerdal A, Blomhoff HK, Funderud S, Smeland EB. 1993. Cell-specific expression of human beta-galactoside alpha 2,6-sialyltransferase transcripts differing in the 5' untranslated region. Eur J Biochem 213:467-475
8. {Bartholomew_BA/Roseman_S.1973.JBC}
Bartholomew BA, Jourdian GW, Roseman S. 1973. The sialic acids. XV. Transfer of sialic acid to glycoproteins by a sialyltransferase from colostrum. J Biol Chem 248:5751-5762
9. {Bast_BJ/Tedder_TF.1992.JCB}
Bast BJ, Zhou LJ, Freeman GJ, Colley KJ, Ernst TJ, Munro JM, Tedder TF. 1992. The HB-6, CDw75, and CD76 differentiation antigens are unique cell-surface carbohydrate determinants generated by the beta-galactoside alpha 2,6-sialyltransferase. J Cell Biol 116:423-435
10. {Chen_C/Colley_KJ.2000.GLYCO}
Chen C, Colley KJ. 2000. Minimal structural and glycosylation requirements for ST6Gal I activity and trafficking. Glycobiology 10:531-583
11. {Coddeville_B/Spik_G.1992.CR}
Coddeville B, Strecker G, Wieruszeski JM, Vliegenthart JF, van Halbeek H, Peter-Katalinic J, Egge H, Spik G. 1992. Heterogeneity of bovine lactotransferrin glycans. Characterization of alpha-D-Galp-(1-->3)-beta-D-Gal- and alpha-NeuAc-(2-->6)-beta-D-GalpNAc-(1-->4)- beta-D-GlcNAc-substituted N-linked glycans. Carbohydr Res 236:145-164
12. {Dall'Olio_F/Santini_D.2000.IJC}
Dall'Olio F, Chiricolo M, Ceccarelli C, Minni F, Marrano D, Santini D. 2000. Beta-galactoside alpha2,6 sialyltransferase in human colon cancer: contribution of multiple transcripts to regulation of enzyme activity and reactivity with Sambucus nigra agglutinin. Int J Cancer 88:58-65
13. {Dalziel_M/Lau_JT.1999.GLYCO}
Dalziel M, Lemaire S, Ewing J, Kobayashi L, Lau JT. 1999. Hepatic acute phase induction of murine beta-galactoside alpha 2,6 sialyltransferase (ST6Gal I) is IL-6 dependent and mediated by elevation of exon H-containing class of transcripts. Glycobiology 9:1003-1008
14. {Dalziel_M/Lau_JTY.2001.GLYCO}
Dalziel M, Huang RY, Dall'Olio F, Morris JR, Taylor-Papadimitriou J, Lau JTY. 2001. Mouse ST6Gal sialyltransferase gene expression during mammary gland lactation. Glycobiology 11:407-12
15. {Datta_AK/Paulson_JC.1995.JBC}
Datta AK, Paulson JC. 1995. The sialyltransferase "sialylmotif" participates in binding the donor substrate CMP-NeuAc. J Biol Chem 270:1497-1500
16. {Datta_AK/Paulson_JC.1998.JBC}
Datta AK, Sinha A, Paulson JC. 1998. Mutation of the sialyltransferase S-sialylmotif alters the kinetics of the donor and acceptor substrates. J Biol Chem 273:9608-9614
17. {Datta_AK/Paulson_JC.2001.JBC}
Datta AK, Chammas R, Paulson JC. 2001. Conserved cysteines in the sialyltransferase sialylmotifs form an essential disulfide bond. J Biol Chem 276:15200-7
18. {Daunter_B/Newlands_J.1981.ANDRO}
Daunter B, Newlands J. 1981. Seminal plasma biochemistry II: seminal plasma and spermatozoal cytidine monophosphate-sialic acid synthetase and sialyltransferase activities. Andrologia 13:215-224
19. {Fast_DG/McCaffrey_G.1993.BBA}
Fast DG, Jamieson JC, McCaffrey G. 1993. The role of the carbohydrate chains of Gal beta-1,4-GlcNAc alpha 2,6-sialyltransferase for enzyme activity. Biochim Biophys Acta 1202:325-330
20. {Geremia_RA/Delannoy_P.1997.GLYCO}
Geremia RA, Harduin-Lepers A, Delannoy P. 1997. Identification of two novel conserved amino acid residues in eukaryotic sialyltransferases: implications for their mechanism of action. Glycobiology 7:V-VII
21. {Grundmann_U/Zettlmeissl_G.1990.NAR}
Grundmann U, Nerlich C, Rein T, Zettlmeissl G. 1990. Complete cDNA sequence encoding human beta-galactoside alpha-2,6-sialyltransferase. Nucleic Acids Res 18:667
22. {Gyorgy_P/Zilliken_F.1974.EJB}
Gyorgy P, Jeanloz RW, Nicolai H von, Zilliken F. 1974. Undialyzable growth factors for Lactobacillus bifidus var. pennsylvanicus. Protective effect of sialic acid bound to glycoproteins and oligosaccharides against bacterial degradation. Eur J Biochem 43:29-33
23. {Hanasaki_K/Bevilacqua_MP.1994.JBC}
Hanasaki K, Varki A, Stamenkovic I, Bevilacqua MP. 1994. Cytokine-induced beta-galactoside alpha-2,6-sialyltransferase in human endothelial cells mediates alpha 2,6-sialylation of adhesion molecules and CD22 ligands. J Biol Chem 269:10637-10643
24. {Hennet_T/Marth_JD.1998.PNASU}
Hennet T, Chui D, Paulson JC, Marth JD. 1998. Immune regulation by the ST6Gal sialyltransferase. Proc Natl Acad Sci U S A 95:4504-4509
25. {Hudgin_RL/Schachter_H.1971.CJB}
Hudgin RL, Schachter H. 1971. Porcine sugar nucleotide: glycoprotein glycosyltransferases. I. Blood serum and liver sialyltransferase. Can J Biochem 49:829-837
26. {Kalcheva_I/Lau_JT.1997.MG}
Kalcheva I, Elliott RW, Dalziel M, Lau JT. 1997. The gene encoding beta-galactoside alpha2,6-sialyltransferase maps to mouse chromosome 16. Mamm Genome 8:619-620
27. {Kitagawa_H/Paulson_JC.1994.JBC}
Kitagawa H, Paulson JC. 1994. Differential expression of five sialyltransferase genes in human tissues. J Biol Chem 269:17872-17878
28. {Lee_YC/Tsuji_S.1999.JBC}
Lee YC, Kaufmann M, Kitazume-Kawaguchi S, Kono M, Takashima S, Kurosawa N, Liu H, Pircher H, Tsuji S. 1999. Molecular cloning and functional expression of two members of mouse NeuAcalpha2,3Galbeta1,3GalNAc GalNAcalpha2,6-sialyltransferase family, ST6GalNAc III and IV. J Biol Chem 274:11958-11967
29. {Li_M/Lance_P.1998.AJP}
Li M, Vemulapalli R, Ullah A, Izu L, Duffey ME, Lance P. 1998. Downregulation of a human colonic sialyltransferase by a secondary bile acid and a phorbol ester. Am J Physiol 274:G599-G606
30. {Lo_NW/Lau_JT.1996.BBRC}
Lo NW, Lau JT. 1996. Novel heterogeneity exists in the 5'-untranslated region of the beta-galactoside alpha 2,6-sialytransferase mRNAs in the human B-lymphoblastoid cell line, louckes. Biochem Biophys Res Commun 228:380-385
31. {Lo_NW/Lau_JT.1996.GLYCO}
Lo NW, Lau JT. 1996. Transcription of the beta-galactoside alpha 2,6-sialyltransferase gene in B lymphocytes is directed by a separate and distinct promoter. Glycobiology 6:271-279
32. {Ma_J/Colley_KJ.1996.JBC}
Ma J, Colley KJ. 1996. A disulfide-bonded dimer of the Golgi beta-galactoside alpha2,6-sialyltransferase is catalytically inactive yet still retains the ability to bind galactose. J Biol Chem 271:7758-7766
33. {Ma_J/Colley_KJ.1997.JBC}
Ma J, Qian R, Rausa FM 3rd, Colley KJ. 1997. Two naturally occurring alpha2,6-sialyltransferase forms with a single amino acid change in the catalytic domain differ in their catalytic activity and proteolytic processing. J Biol Chem 272:672-679
34. {Ma_J/Colley_KJ.1999.JBC}
Ma J, Simonovic M, Qian R, Colley KJ. 1999. Sialyltransferase isoforms are phosphorylated in the cis-medial Golgi on serine and threonine residues in their luminal sequences. J Biol Chem 274:8046-8052
35. {Manzella_SM/Baenziger_JU.1997.JBC}
Manzella SM, Dharmesh SM, Cohick CB, Soares MJ, Baenziger JU. 1997. Developmental regulation of a pregnancy-specific oligosaccharide structure, NeuAcalpha2,6GalNAcbeta1,4GlcNAc, on select members of the rat placental prolactin family. J Biol Chem 272:4775-4782
36. {Nakata_N/Kobata_A.1993.BIOCH}
Nakata N, Furukawa K, Greenwalt DE, Sato T, Kobata A. 1993. Structural study of the sugar chains of CD36 purified from bovine mammary epithelial cells: occurrence of novel hybrid-type sugar chains containing the Neu5Ac alpha 2-->6GalNAc beta 1-->4GlcNAc and the Man alpha 1-->2Man alpha 1-->3Man alpha 1-->6Man grou. Biochemistry 32:4369-4383
37. {Nemansky_M/Van_den_Eijnden_DH.1992.BJ}
Nemansky M, Van den Eijnden DH. 1992. Bovine colostrum CMP-NeuAc:Gal beta(1-->4)GlcNAc-R alpha(2-->6)-sialyltransferase is involved in the synthesis of the terminal NeuAc alpha(2-->6)GalNAc beta(1-->4)GlcNAc sequence occurring on N-linked glycans of bovine milk glycoproteins. Biochem J 287:311-316
38. {Okajima_T/Furukawa_K.1999.JBC}
Okajima T, Fukumoto S, Miyazaki H, Ishida H, Kiso M, Furukawa K, Urano T, Furukawa K. 1999. Molecular cloning of a novel alpha2,3-sialyltransferase (ST3Gal VI) that sialylates type II lactosamine structures on glycoproteins and glycolipids. J Biol Chem 274:11479-11486
39. {Powell_LD/Varki_A.1994.JBC}
Powell LD, Varki A. 1994. The oligosaccharide binding specificities of CD22 beta, a sialic acid-specific lectin of B cells. J Biol Chem 269:10628-10636
40. {Ratnam_S/Mookerjea_S.1981.BBA}
Ratnam S, Fraser IH, Collins JM, Lawrence JA, Barrowman JA, Mookerjea S. 1981. Elevated sialyltransferase activity in the intestinal lymph of colchicine-treated rats. Biochim Biophys Acta 673:435-442
41. {Roth_J/Paulson_JC.1985.CELL}
Roth J, Taatjes DJ, Lucocq JM, Weinstein J, Paulson JC. 1985. Demonstration of an extensive trans-tubular network continuous with the Golgi apparatus stack that may function in glycosylation. Cell 43:287-295
42. {Shah_S/Baumann_H.1992.JBC}
Shah S, Lance P, Smith TJ, Berenson CS, Cohen SA, Horvath PJ, Lau JT, Baumann H. 1992. n-butyrate reduces the expression of beta-galactoside alpha 2,6-sialyltransferase in Hep G2 cells. J Biol Chem 267:10652-10658
43. {Svensson_EC/Paulson_JC.1992.JBC}
Svensson EC, Conley PB, Paulson JC. 1992. Regulated expression of alpha 2,6-sialyltransferase by the liver-enriched transcription factors HNF-1, DBP, and LAP. J Biol Chem 267:3466-3472
44. {Taatjes_DJ/Roth_J.1986.EJCB}
Taatjes DJ, Roth J. 1986. The trans-tubular network of the hepatocyte Golgi apparatus is part of the secretory pathway. Eur J Cell Biol 42:344-350
45. {Taatjes_DJ/Shaper_JH.1987.EJCB}
Taatjes DJ, Roth J, Weinstein J, Paulson JC, Shaper NL, Shaper JH. 1987. Codistribution of galactosyl- and sialyltransferase: reorganization of trans Golgi apparatus elements in hepatocytes in intact liver and cell culture. Eur J Cell Biol 44:187-194
46. {Taniguchi_A/Matsumoto_K.2000.GLYCO}
Taniguchi A, Hasegawa Y, Higai K, Matsumoto K. 2000. Transcriptional regulation of human beta-galactoside alpha2, 6-sialyltransferase (hST6Gal I) gene during differentiation of the HL-60 cell line. Glycobiology 10:623-628
47. {Tsuji_S/Paulson_JC.1996.GLYCO}
Tsuji S, Datta AK, Paulson JC. 1996. Systematic nomenclature for sialyltransferases. Glycobiology 6:V-VII
48. {Varki_A.1992.GLYCO}
Varki A. 1992. Diversity in the sialic acids. Glycobiology 2:25-40
49. {Vertino-Bell_A/Lau_JT.1994.DB}
Vertino-Bell A, Ren J, Black JD, Lau JT. 1994. Developmental regulation of beta-galactoside alpha 2,6-sialyltransferase in small intestine epithelium. Dev Biol 165:126-136
50. {Wang_X/Lau_JT.1993.JBC}
Wang X, Vertino A, Eddy RL, Byers MG, Jani-Sait SN, Shows TB, Lau JT. 1993. Chromosome mapping and organization of the human beta-galactoside alpha 2,6-sialyltransferase gene. Differential and cell-type specific usage of upstream exon sequences in B-lymphoblastoid cells. J Biol Chem 268:4355-4361
51. {Wang_XC/Lau_JT.1989.JBC}
Wang XC, O'Hanlon TP, Lau JT. 1989. Regulation of beta-galactoside alpha 2,6-sialyltransferase gene expression by dexamethasone. J Biol Chem 264:1854-1859
52. {Wang_XC/Lau_JT.1990.JBC}
Wang XC, Smith TJ, Lau JT. 1990. Transcriptional regulation of the liver beta-galactoside alpha 2,6-sialyltransferase by glucocorticoids. J Biol Chem 265:17849-17853
53. {Weinstein_J/Paulson_JC.1982.JBC}
Weinstein J, de Souza-e-Silva U, Paulson JC. 1982. Purification of a Gal beta 1 to 4GlcNAc alpha 2 to 6 sialyltransferase and a Gal beta 1 to 3(4)GlcNAc alpha 2 to 3 sialyltransferase to homogeneity from rat liver. J Biol Chem 257:13835-13844

WWW Resources

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* indicates amended by reviewer, ** indicates added by reviewer
Modified 02/15/01 prow@ncbi.nlm.nih.gov