Abstract |
We have previously documented a dramatic elevation in the activity of alpha 2,6-sialytransferase towards Gal beta 1,4GlcNAc (EC 2.4.99.1) (alpha 2,6ST) in CaCo-2 cells maintained in culture for several days after confluence to elicit a high degree of enterocytic differentiation phenotype. Northern analysis performed with a probe complementary to a region of human alpha 2,6ST mRNA common to all known transcripts demonstrated that the expression of alpha 2,6ST mRNA in CaCo-2 cells increased with the degree with the degree of differentiation. When probes complementary to 5'-untranslated exons (Y + Z or X) previously identified in transcripts isolated from human placenta and from several human lymphoblastoid cell lines were used, no hybridization signal with mRNA of CaCo-2 cells was found, as reported for the mRNA of hepatoma cell line HepG2 (Wang XC, Vertino A, Eddy RL, Byers MG, Jani-Sait SN, Shows TB, Lau JTY (1993) J Biol Chem 268: 4355-61). These results support the notion that the major alpha 2,6ST transcript of CaCo-2 cells was the hepatoma isoform or a new one, so far unreported. Consistent with the differentiation-dependent increase in alpha 2,6ST-mRNA expression, an elevation of the reactivity with Sambucus nigra agglutinin of differentiated CaCo-2 cell-surface was observed, indicating an enhanced alpha 2,6-sialylation of membrane glycoconjugates.
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Authors | F Dall'Olio, N Malagolini, S Guerrini, J T Lau, F Serafini-Cessi |
Journal | Glycoconjugate journal
(Glycoconj J)
Vol. 13
Issue 1
Pg. 115-21
(Feb 1996)
ISSN: 0282-0080 [Print] United States |
PMID | 8785482
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- DNA Primers
- Glycoconjugates
- Oligosaccharides
- RNA, Messenger
- Sialyltransferases
- beta-D-Galactoside alpha 2-6-Sialyltransferase
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Topics |
- Base Sequence
- Caco-2 Cells
(enzymology)
- Carbohydrate Sequence
- Cell Differentiation
- DNA Primers
(genetics)
- Gene Expression
- Glycoconjugates
(chemistry, metabolism)
- Humans
- Kinetics
- Molecular Sequence Data
- Oligosaccharides
(chemistry, metabolism)
- RNA, Messenger
(genetics, metabolism)
- Sialyltransferases
(genetics, metabolism)
- Substrate Specificity
- beta-D-Galactoside alpha 2-6-Sialyltransferase
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