Differentiation -dependent expression of human beta-galactoside alpha 2,6-sialyltransferase mRNA in colon carcinoma CaCo-2 cells.

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.

• 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.)

Chemical References

• DNA Primers
• Glycoconjugates
• Oligosaccharides
• RNA, Messenger
• Sialyltransferases
• beta-D-Galactoside alpha 2-6-Sialyltransferase

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