Glucocorticoid induction of the α2,6 sialyltransferase enzyme in a mouse neural cell line

✍ Scribed by Christine M. Coughlan; Kieran C. Breen

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 272 KB
• Volume: 51
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19980301)51:5<619::aid-jnr9>3.0.co;2-i

✦ Synopsis

Combined sialyltransferase (ST) activities were induced in the HN9 hippocampal cell line following treatment with the synthetic glucocorticoid dexamethasone (dex) for 24 hr. Induction occurred in a dosedependent manner, with the maximum induction of a 2-fold increase over control enzyme levels occurring at a concentration of 10 -8 M dex. A minimum of 6 hr pretreatment with drug was required before significant induction could be detected and elevated enzyme levels persisted for up to 48 hr post-treatment. The induced form of the enzyme showed an increase in reaction maximum velocity (V max ) while showing no change in affinity (K m ) for the acceptor substrate asialofetuin. The ␣2,6 ST enzyme was demonstrated to be the primary enzyme induced and there was no change in expression of the ␣2,3 ST enzyme. Lectin blot analysis demonstrated an increase in the levels of the ␣2,6-linked cellular sialoglycoproteins and a parallel decrease in the ␣2,3 sialoglycoprotein levels.