TRANSCRIPTIONAL CONTROL OF THE HUMAN HARVEY RAS PROTOONCOGENE - ROLE OF MULTIPLE ELEMENTS IN THE PROMOTER REGION

In the promoter region of the human c-Ha-rasl gene, multiple elements for transcriptional control are dispersed. To examine the role of each element, we made a series of deletion mutants of this promoter region, including internal deletion mutants, and measured the promoter activities of these mutants. Any two of the four Spl-binding sites upstream from the CCAAT-box element were sufficient for the maximal activity of the c-Ha-rasl promoter. Either one of the two Spl-binding sites downstream from the CACCC-box element was also necessary for the maximal promoter activity. Deletion of the CCAAT-box or CACCC-box elements reduced the level of transcription to 25% or 41% of that with the wild-type promoter. These results indicated that at least three Spl-binding sites, and the CCAAT-box and CACCC-box elements contributed in concert to the activity of the human c-Ha-rasl promoter. © 1990.