PEPCK Gene as Model of Inhibitory Effects of Insulin on Gene Transcription

Abstract

Regulation of gene transcription is a major action of insulin. Most of the >20 examples of this effect involve the stimulation of transcription, but a few involve an inhibition. The inhibition of transcription of the phosphoenolpyruvate carboxykinase (PEPCK) gene has been studied in detail. Most of this effect is exerted at the level of transcription initiation. Hormone effects on transcription are thought to be mediated through cisacting DNA sequences located in the 5'-flanking sequence adjacent to the transcription initiation site. The techniques of transient and stable transfection of fusion genes containing various segments of the PEPCKgene promoter are being used to locate the insulinresponsive sequences.