Transcriptional activation and stabilization of malic enzyme mRNA precursor by thyroid hormone.

摘要: One of the responses to administration thyroid hormone is an increase in malic enzyme (EC 1.1.1.40) mRNA rat liver. We have previously shown that 3,5,3'-triiodo-L-thyronine (T3) causes a 3-4-fold rate transcription gene as determined by vitro run-off assays with cDNA probe following T3 treatment for 10 days (Dozin, B., Magnuson, M.A., and Nikodem, V. M. (1986) J. Biol. Chem. 261, 10290-10292). Since level cytoplasmic increases 10-15-fold, one or more additional mechanisms must be operative produce full effect. now analyzed time course effect on accumulation RNA nucleus using cDNAs intronic probes. There approximately 10-12-fold nuclear accompanied same mRNA, showing half-rise about 60 h. The occurred half-time 18 relative values either transcriptional activity were identical irrespective probes used. As control, we examined high carbohydrate diet which known without affecting Rall, E., Proc. Natl. Acad. Sci. U.S.A. 83, 4705-4709). expected, no change was found conclude both activates liver decreases degradation pre-mRNA coding enzyme.