Induction of mRNA for phosphoenolpyruvate carboxykinase (GTP) by dexamethasone in cultured rat hepatocytes requires on-going protein synthesis.
Dexamethasone is necessary and sufficient to induce mRNA for phosphoenolpyruvate carboxykinase (GTP) (PEPCK) by 19-fold in rat hepatocytes cultured in serum-free medium. However, the time required for maximum induction is 16 h. The slow induction suggested that glucocorticoids regulate the expression of an intermediate gene product(s) which is required for glucocorticoid stimulation of PEPCK-gene expression. Consistent with this notion was the finding that cycloheximide completely blocked the response to dexamethasone. In contrast, cycloheximide did not block the response to a cyclic AMP analogue.
Nebes
V L
VL
Department of Microbiology, Biochemistry and Molecular Biology, University of Pittsburgh, PA 15261.
Morris
S M
SM
D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D005786:Gene Expression Regulation; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000235:genetics*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013873:Thionucleotides / Q000494:pharmacology
D012333:RNA, Messenger; D013873:Thionucleotides; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D003907:Dexamethasone; D003513:Cycloheximide; D000242:Cyclic AMP; D010729:Phosphoenolpyruvate Carboxykinase (GTP)