Transcriptional induction of beta-galactoside alpha-2,6-sialyltransferase in rat fibroblast by dexamethasone.

The beta-galactoside alpha-2,6-sialyltransferase activity of Fisher rat fibroblasts is enhanced by dexamethasone while the activity of the beta-galactoside alpha-2,3-sialyltransferase remains unchanged. This glucocorticoid-dependent activation can be inhibited by the antagonist RU 38,486 and results from an elevated transcription rate of the 4.7-kb mRNA previously characterized in rat fibroblasts, distinct from the 4.3-kb liver-restricted mRNA. As shown by the binding of radiolabelled Sambucus nigra agglutinin, this activation leads to an increase of NeuNAc(alpha 2-6)Gal sequences on glycoproteins isolated from the dexamethasone-treated cells.