Involvement of tristetraprolin in transcriptional activation of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase by insulin
- Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, FL 33612 (United States)
Highlights: Black-Right-Pointing-Pointer siRNAs to tristetraprolin blocks transcription of HMGR in vivo in rat liver. Black-Right-Pointing-Pointer siRNAs to tristetraprolin inhibits insulin activation of HMGR transcription. Black-Right-Pointing-Pointer Insulin acts to rapidly increase tristetraprolin in liver nuclear extracts. -- Abstract: Several AU-rich RNA binding element (ARE) proteins were investigated for their possible effects on transcription of hepatic 3-hydroxy-3-methyglutaryl coenzyme A reductase (HMGR) in normal rats. Using in vivo electroporation, four different siRNAs to each ARE protein were introduced together with HMGR promoter (-325 to +20) luciferase construct and compared to saline controls. All four siRNAs to tristetraprolin (TTP) completely eliminated transcription from the HMGR promoter construct. Since insulin acts to rapidly increase hepatic HMGR transcription, the effect of TTP siRNA on induction by insulin was tested. The 3-fold stimulation by insulin was eliminated by this treatment. In comparison, siRNA to AU RNA binding protein/enoyl coenzyme A hydratase (AUH) had no effect. These findings indicate a role for TTP in the insulin-mediated activation of hepatic HMGR transcription.
- OSTI ID:
- 22207788
- Journal Information:
- Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 1 Vol. 420; ISSN 0006-291X; ISSN BBRCA9
- Country of Publication:
- United States
- Language:
- English
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