Characterization of a novel Foxa (hepatocyte nuclear factor-3) site in the glucagon promoter that is conserved between rodents and humans.

ABSTRACT: The pancreatic islet hormone glucagon stimulates hepatic glucose production and thus maintains blood glucose levels in the fasting state. Transcription factors of the Foxa [Fox (forkhead box) subclass A; also known as HNF-3 (hepatocyte nuclear factor-3)] family are required for cell-specific activation of the glucagon gene in pancreatic islet alpha-cells. However, their action on the glucagon gene is poorly understood. In the present study, comparative sequence analysis and molecular characterization using protein-DNA binding and transient transfection assays revealed that the well-characterized Foxa-binding site in the G2 enhancer element of the rat glucagon gene is not conserved in humans and that the human G2 sequence lacks basal enhancer activity. A novel Foxa site was identified that

SUBMITTER: Sharma SK 

PROVIDER: S-EPMC1180734 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature