Cloning and characterization of the TATA-less promoter from the human GFI1 proto-oncogene.

The growth factor independent 1 (GFI1) gene encodes a zinc finger protein which acts as a transcriptional repressor and confers growth factor independence on tumor cells, as suggested by the study of its mouse ortholog, Gfi1. We previously isolated the human GFI1 gene but no information about the structure and location of the promotor of this gene has been reported. In this study we have cloned and characterized the human GFI1 promoter. The nucleotide sequence of the promoter region is GC-rich and does not contain a typical TATA or CAAT box. Several Sp1 sites are present and computer predictions indicate that either of the two Sp1 sites might serve as the sites for transcription initiation. Analysis of various lengths of the promoter region using the luciferase reporter assay identifies a functional promoter that is active in NIH3T3 cells. The strongest activity lies within a region 312-602 basepairs upstream from the translation start site.