Following 70% hepatectomy, the induction of tyrosine aminotransferase mRNA by glucocorticoids was marginal at 1.5 h, significantly impaired between 3 and 8 h and, at 16 h post-hepatectomy, reached a value approx. 5-fold the basal level, similar to the level observed in quiescent liver. The fold induction of the mRNA was accounted for by a similar fold activation of transcription of the gene by glucocorticoids in regenerating but not in quiescent liver; in the latter, activation of transcription was marginal in spite of glucocorticoid-induced hypersensitivity to cleavage by DNase I at the glucocorticoid-dependent enhancer of the gene. The possibility that in quiescent liver glucocorticoids act at a transcriptional step beyond initiation, increasing the rate of elongation or overcoming a blockage in elongation, was excluded. However, a similar fold induction was determined for total and nuclear tyrosine aminotransferase mRNA in the presence of glucocorticoids, suggesting that in quiescent liver glucocorticoids promote efficient maturation of the tyrosine aminotransferase primary transcript. Thus a glucocorticoid-induced nuclear post-transcriptional up-regulation apparently compensates for impaired activation of transcription of the tyrosine aminotransferase gene by glucocorticoids in quiescent liver.
Skip Nav Destination
Article navigation
December 1996
- Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
Research Article|
December 15 1996
Regulation of tyrosine aminotransferase gene expression by glucocorticoids in quiescent and regenerating liver
Michael N. ALEXIS
Michael N. ALEXIS
*
1Institute of Biological Research and Biotechnology, The National Hellenic Research Foundation, 48 Vas. Constantinou Ave., Athens 11635, Greece
*To whom correspondence should be addressed.
Search for other works by this author on:
Biochem J (1996) 320 (3): 745–753.
Article history
Received:
April 01 1996
Revision Received:
July 15 1996
Accepted:
August 16 1996
Citation
Lia BAKI, Michael N. ALEXIS; Regulation of tyrosine aminotransferase gene expression by glucocorticoids in quiescent and regenerating liver. Biochem J 15 December 1996; 320 (3): 745–753. doi: https://doi.org/10.1042/bj3200745
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Biochemical Society Member Sign in
Sign InSign in via your Institution
Sign in via your InstitutionGet Access To This Article
Cited By
Related Articles
Effects of methylprednisolone on the energy metabolism of quiescent and conA-stimulated thymocytes of the rat
Biosci Rep (February,1993)
Bioenergetics of Human Peripheral Blood Mononuclear Cell Metabolism in Quiescent, Activated, and Glucocorticoid-Treated States
Biosci Rep (August,2000)
Among translational effectors, p70S6k is uniquely sensitive to inhibition by glucocorticoids
Biochem J (April,2000)