TRANSCRIPTIONAL REGULATION OF THE HEPATIC GLUTAMINASE GENE IN THE STREPTOZOTOCIN-DIABETIC RAT

1. Liver possesses a unique isozyme of phosphate activated glutaminase which is subject to long-term regulation. 2. In the rat streptozotoci n-diabetes results in a 4-fold increase in the rate of transcription o f the rat hepatic glutaminase gene. 3. This is consistent with previou s reports from this laboratory of increases, of similar magnitude, in the relative abundance of hepatic glutaminase mRNA (Smith and Watford (1990) J. Biol. Chem. 265, 10631-10636), and enzyme activity (Watford, et al. (1984) Biochem. J. 224, 207-214). 4. The work establishes that , in contrast to the regulation of renal glutaminase where mRNA stabil ity plays an important role, the predominant site of long-term regulat ion of hepatic glutaminase is at the level of gene transcription.