UPSTREAM ELEMENT FROM THE HUMAN INSULIN-RECEPTOR GENE PROMOTER CONTAINS BINDING-SITES FOR C EBP-BETA AND NF-1/

We have shown previously that a 500-bp region of the human insulin rec eptor promoter (-0.3 to -1.8 kb) was able to stimulate transcription f rom a heterologous thymidine kinase promoter in HepG2 hepatoma cells b ut not in Hela fibroblasts. Footprint analysis localized the transcrip tion factor binding sites to a 36-bp region at -1420. In this paper, w e analyze the factors that recognize this element and show that it con tains binding sites for the CAAT/enhancer binding protein C/EBP and nu clear factor 1 (NF-1). in addition we show that both C/EBP alpha and t he C/EBP beta can transactivate the human insulin receptor promoter in a dose-dependent manner.